FFPROBE-ALL(1)                                                                                                       FFPROBE-ALL(1)

NAME
       ffprobe - ffprobe media prober

SYNOPSIS
       ffprobe [options] input_url

DESCRIPTION
       ffprobe gathers information from multimedia streams and prints it in human- and machine-readable fashion.

       For example it can be used to check the format of the container used by a multimedia stream and the format and type of each
       media stream contained in it.

       If a url is specified in input, ffprobe will try to open and probe the url content. If the url cannot be opened or
       recognized as a multimedia file, a positive exit code is returned.

       If no output is specified as output with o ffprobe will write to stdout.

       ffprobe may be employed both as a standalone application or in combination with a textual filter, which may perform more
       sophisticated processing, e.g. statistical processing or plotting.

       Options are used to list some of the formats supported by ffprobe or for specifying which information to display, and for
       setting how ffprobe will show it.

       ffprobe output is designed to be easily parsable by a textual filter, and consists of one or more sections of a form defined
       by the selected writer, which is specified by the print_format option.

       Sections may contain other nested sections, and are identified by a name (which may be shared by other sections), and an
       unique name. See the output of sections.

       Metadata tags stored in the container or in the streams are recognized and printed in the corresponding "FORMAT", "STREAM"
       or "PROGRAM_STREAM" section.

OPTIONS
       All the numerical options, if not specified otherwise, accept a string representing a number as input, which may be followed
       by one of the SI unit prefixes, for example: 'K', 'M', or 'G'.

       If 'i' is appended to the SI unit prefix, the complete prefix will be interpreted as a unit prefix for binary multiples,
       which are based on powers of 1024 instead of powers of 1000. Appending 'B' to the SI unit prefix multiplies the value by 8.
       This allows using, for example: 'KB', 'MiB', 'G' and 'B' as number suffixes.

       Options which do not take arguments are boolean options, and set the corresponding value to true. They can be set to false
       by prefixing the option name with "no". For example using "-nofoo" will set the boolean option with name "foo" to false.

   Stream specifiers
       Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers are used to precisely specify which stream(s)
       a given option belongs to.

       A stream specifier is a string generally appended to the option name and separated from it by a colon. E.g. "-codec:a:1 ac3"
       contains the "a:1" stream specifier, which matches the second audio stream. Therefore, it would select the ac3 codec for the
       second audio stream.

       A stream specifier can match several streams, so that the option is applied to all of them. E.g. the stream specifier in
       "-b:a 128k" matches all audio streams.

       An empty stream specifier matches all streams. For example, "-codec copy" or "-codec: copy" would copy all the streams
       without reencoding.

       Possible forms of stream specifiers are:

       stream_index
           Matches the stream with this index. E.g. "-threads:1 4" would set the thread count for the second stream to 4. If
           stream_index is used as an additional stream specifier (see below), then it selects stream number stream_index from the
           matching streams. Stream numbering is based on the order of the streams as detected by libavformat except when a program
           ID is also specified. In this case it is based on the ordering of the streams in the program.

       stream_type[:additional_stream_specifier]
           stream_type is one of following: 'v' or 'V' for video, 'a' for audio, 's' for subtitle, 'd' for data, and 't' for
           attachments. 'v' matches all video streams, 'V' only matches video streams which are not attached pictures, video
           thumbnails or cover arts. If additional_stream_specifier is used, then it matches streams which both have this type and
           match the additional_stream_specifier. Otherwise, it matches all streams of the specified type.

       p:program_id[:additional_stream_specifier]
           Matches streams which are in the program with the id program_id. If additional_stream_specifier is used, then it matches
           streams which both are part of the program and match the additional_stream_specifier.

       #stream_id or i:stream_id
           Match the stream by stream id (e.g. PID in MPEG-TS container).

       m:key[:value]
           Matches streams with the metadata tag key having the specified value. If value is not given, matches streams that
           contain the given tag with any value.

       u   Matches streams with usable configuration, the codec must be defined and the essential information such as video
           dimension or audio sample rate must be present.

           Note that in ffmpeg, matching by metadata will only work properly for input files.

   Generic options
       These options are shared amongst the ff* tools.

       -L  Show license.

       -h, -?, -help, --help [arg]
           Show help. An optional parameter may be specified to print help about a specific item. If no argument is specified, only
           basic (non advanced) tool options are shown.

           Possible values of arg are:

           long
               Print advanced tool options in addition to the basic tool options.

           full
               Print complete list of options, including shared and private options for encoders, decoders, demuxers, muxers,
               filters, etc.

           decoder=decoder_name
               Print detailed information about the decoder named decoder_name. Use the -decoders option to get a list of all
               decoders.

           encoder=encoder_name
               Print detailed information about the encoder named encoder_name. Use the -encoders option to get a list of all
               encoders.

           demuxer=demuxer_name
               Print detailed information about the demuxer named demuxer_name. Use the -formats option to get a list of all
               demuxers and muxers.

           muxer=muxer_name
               Print detailed information about the muxer named muxer_name. Use the -formats option to get a list of all muxers and
               demuxers.

           filter=filter_name
               Print detailed information about the filter named filter_name. Use the -filters option to get a list of all filters.

           bsf=bitstream_filter_name
               Print detailed information about the bitstream filter named bitstream_filter_name.  Use the -bsfs option to get a
               list of all bitstream filters.

           protocol=protocol_name
               Print detailed information about the protocol named protocol_name.  Use the -protocols option to get a list of all
               protocols.

       -version
           Show version.

       -buildconf
           Show the build configuration, one option per line.

       -formats
           Show available formats (including devices).

       -demuxers
           Show available demuxers.

       -muxers
           Show available muxers.

       -devices
           Show available devices.

       -codecs
           Show all codecs known to libavcodec.

           Note that the term 'codec' is used throughout this documentation as a shortcut for what is more correctly called a media
           bitstream format.

       -decoders
           Show available decoders.

       -encoders
           Show all available encoders.

       -bsfs
           Show available bitstream filters.

       -protocols
           Show available protocols.

       -filters
           Show available libavfilter filters.

       -pix_fmts
           Show available pixel formats.

       -sample_fmts
           Show available sample formats.

       -layouts
           Show channel names and standard channel layouts.

       -dispositions
           Show stream dispositions.

       -colors
           Show recognized color names.

       -sources device[,opt1=val1[,opt2=val2]...]
           Show autodetected sources of the input device.  Some devices may provide system-dependent source names that cannot be
           autodetected.  The returned list cannot be assumed to be always complete.

                   ffmpeg -sources pulse,server=192.168.0.4

       -sinks device[,opt1=val1[,opt2=val2]...]
           Show autodetected sinks of the output device.  Some devices may provide system-dependent sink names that cannot be
           autodetected.  The returned list cannot be assumed to be always complete.

                   ffmpeg -sinks pulse,server=192.168.0.4

       -loglevel [flags+]loglevel | -v [flags+]loglevel
           Set logging level and flags used by the library.

           The optional flags prefix can consist of the following values:

           repeat
               Indicates that repeated log output should not be compressed to the first line and the "Last message repeated n
               times" line will be omitted.

           level
               Indicates that log output should add a "[level]" prefix to each message line. This can be used as an alternative to
               log coloring, e.g. when dumping the log to file.

           Flags can also be used alone by adding a '+'/'-' prefix to set/reset a single flag without affecting other flags or
           changing loglevel. When setting both flags and loglevel, a '+' separator is expected between the last flags value and
           before loglevel.

           loglevel is a string or a number containing one of the following values:

           quiet, -8
               Show nothing at all; be silent.

           panic, 0
               Only show fatal errors which could lead the process to crash, such as an assertion failure. This is not currently
               used for anything.

           fatal, 8
               Only show fatal errors. These are errors after which the process absolutely cannot continue.

           error, 16
               Show all errors, including ones which can be recovered from.

           warning, 24
               Show all warnings and errors. Any message related to possibly incorrect or unexpected events will be shown.

           info, 32
               Show informative messages during processing. This is in addition to warnings and errors. This is the default value.

           verbose, 40
               Same as "info", except more verbose.

           debug, 48
               Show everything, including debugging information.

           trace, 56

           For example to enable repeated log output, add the "level" prefix, and set loglevel to "verbose":

                   ffmpeg -loglevel repeat+level+verbose -i input output

           Another example that enables repeated log output without affecting current state of "level" prefix flag or loglevel:

                   ffmpeg [...] -loglevel +repeat

           By default the program logs to stderr. If coloring is supported by the terminal, colors are used to mark errors and
           warnings. Log coloring can be disabled setting the environment variable AV_LOG_FORCE_NOCOLOR, or can be forced setting
           the environment variable AV_LOG_FORCE_COLOR.

       -report
           Dump full command line and log output to a file named "program-YYYYMMDD-HHMMSS.log" in the current directory.  This file
           can be useful for bug reports.  It also implies "-loglevel debug".

           Setting the environment variable FFREPORT to any value has the same effect. If the value is a ':'-separated key=value
           sequence, these options will affect the report; option values must be escaped if they contain special characters or the
           options delimiter ':' (see the ``Quoting and escaping'' section in the ffmpeg-utils manual).

           The following options are recognized:

           file
               set the file name to use for the report; %p is expanded to the name of the program, %t is expanded to a timestamp,
               "%%" is expanded to a plain "%"

           level
               set the log verbosity level using a numerical value (see "-loglevel").

           For example, to output a report to a file named ffreport.log using a log level of 32 (alias for log level "info"):

                   FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output

           Errors in parsing the environment variable are not fatal, and will not appear in the report.

       -hide_banner
           Suppress printing banner.

           All FFmpeg tools will normally show a copyright notice, build options and library versions. This option can be used to
           suppress printing this information.

       -cpuflags flags (global)
           Allows setting and clearing cpu flags. This option is intended for testing. Do not use it unless you know what you're
           doing.

                   ffmpeg -cpuflags -sse+mmx ...
                   ffmpeg -cpuflags mmx ...
                   ffmpeg -cpuflags 0 ...

           Possible flags for this option are:

           x86
               mmx
               mmxext
               sse
               sse2
               sse2slow
               sse3
               sse3slow
               ssse3
               atom
               sse4.1
               sse4.2
               avx
               avx2
               xop
               fma3
               fma4
               3dnow
               3dnowext
               bmi1
               bmi2
               cmov
           ARM
               armv5te
               armv6
               armv6t2
               vfp
               vfpv3
               neon
               setend
           AArch64
               armv8
               vfp
               neon
           PowerPC
               altivec
           Specific Processors
               pentium2
               pentium3
               pentium4
               k6
               k62
               athlon
               athlonxp
               k8
       -cpucount count (global)
           Override detection of CPU count. This option is intended for testing. Do not use it unless you know what you're doing.

                   ffmpeg -cpucount 2

       -max_alloc bytes
           Set the maximum size limit for allocating a block on the heap by ffmpeg's family of malloc functions. Exercise extreme
           caution when using this option. Don't use if you do not understand the full consequence of doing so.  Default is
           INT_MAX.

   AVOptions
       These options are provided directly by the libavformat, libavdevice and libavcodec libraries. To see the list of available
       AVOptions, use the -help option. They are separated into two categories:

       generic
           These options can be set for any container, codec or device. Generic options are listed under AVFormatContext options
           for containers/devices and under AVCodecContext options for codecs.

       private
           These options are specific to the given container, device or codec. Private options are listed under their corresponding
           containers/devices/codecs.

       For example to write an ID3v2.3 header instead of a default ID3v2.4 to an MP3 file, use the id3v2_version private option of
       the MP3 muxer:

               ffmpeg -i input.flac -id3v2_version 3 out.mp3

       All codec AVOptions are per-stream, and thus a stream specifier should be attached to them:

               ffmpeg -i multichannel.mxf -map 0:v:0 -map 0:a:0 -map 0:a:0 -c:a:0 ac3 -b:a:0 640k -ac:a:1 2 -c:a:1 aac -b:2 128k out.mp4

       In the above example, a multichannel audio stream is mapped twice for output.  The first instance is encoded with codec ac3
       and bitrate 640k.  The second instance is downmixed to 2 channels and encoded with codec aac. A bitrate of 128k is specified
       for it using absolute index of the output stream.

       Note: the -nooption syntax cannot be used for boolean AVOptions, use -option 0/-option 1.

       Note: the old undocumented way of specifying per-stream AVOptions by prepending v/a/s to the options name is now obsolete
       and will be removed soon.

   Main options
       -f format
           Force format to use.

       -unit
           Show the unit of the displayed values.

       -prefix
           Use SI prefixes for the displayed values.  Unless the "-byte_binary_prefix" option is used all the prefixes are decimal.

       -byte_binary_prefix
           Force the use of binary prefixes for byte values.

       -sexagesimal
           Use sexagesimal format HH:MM:SS.MICROSECONDS for time values.

       -pretty
           Prettify the format of the displayed values, it corresponds to the options "-unit -prefix -byte_binary_prefix
           -sexagesimal".

       -of, -print_format writer_name[=writer_options]
           Set the output printing format.

           writer_name specifies the name of the writer, and writer_options specifies the options to be passed to the writer.

           For example for printing the output in JSON format, specify:

                   -print_format json

           For more details on the available output printing formats, see the Writers section below.

       -sections
           Print sections structure and section information, and exit. The output is not meant to be parsed by a machine.

       -select_streams stream_specifier
           Select only the streams specified by stream_specifier. This option affects only the options related to streams (e.g.
           "show_streams", "show_packets", etc.).

           For example to show only audio streams, you can use the command:

                   ffprobe -show_streams -select_streams a INPUT

           To show only video packets belonging to the video stream with index 1:

                   ffprobe -show_packets -select_streams v:1 INPUT

       -show_data
           Show payload data, as a hexadecimal and ASCII dump. Coupled with -show_packets, it will dump the packets' data. Coupled
           with -show_streams, it will dump the codec extradata.

           The dump is printed as the "data" field. It may contain newlines.

       -show_data_hash algorithm
           Show a hash of payload data, for packets with -show_packets and for codec extradata with -show_streams.

       -show_error
           Show information about the error found when trying to probe the input.

           The error information is printed within a section with name "ERROR".

       -show_format
           Show information about the container format of the input multimedia stream.

           All the container format information is printed within a section with name "FORMAT".

       -show_format_entry name
           Like -show_format, but only prints the specified entry of the container format information, rather than all. This option
           may be given more than once, then all specified entries will be shown.

           This option is deprecated, use "show_entries" instead.

       -show_entries section_entries
           Set list of entries to show.

           Entries are specified according to the following syntax. section_entries contains a list of section entries separated by
           ":". Each section entry is composed by a section name (or unique name), optionally followed by a list of entries local
           to that section, separated by ",".

           If section name is specified but is followed by no "=", all entries are printed to output, together with all the
           contained sections. Otherwise only the entries specified in the local section entries list are printed. In particular,
           if "=" is specified but the list of local entries is empty, then no entries will be shown for that section.

           Note that the order of specification of the local section entries is not honored in the output, and the usual display
           order will be retained.

           The formal syntax is given by:

                   <LOCAL_SECTION_ENTRIES> ::= <SECTION_ENTRY_NAME>[,<LOCAL_SECTION_ENTRIES>]
                   <SECTION_ENTRY>         ::= <SECTION_NAME>[=[<LOCAL_SECTION_ENTRIES>]]
                   <SECTION_ENTRIES>       ::= <SECTION_ENTRY>[:<SECTION_ENTRIES>]

           For example, to show only the index and type of each stream, and the PTS time, duration time, and stream index of the
           packets, you can specify the argument:

                   packet=pts_time,duration_time,stream_index : stream=index,codec_type

           To show all the entries in the section "format", but only the codec type in the section "stream", specify the argument:

                   format : stream=codec_type

           To show all the tags in the stream and format sections:

                   stream_tags : format_tags

           To show only the "title" tag (if available) in the stream sections:

                   stream_tags=title

       -show_packets
           Show information about each packet contained in the input multimedia stream.

           The information for each single packet is printed within a dedicated section with name "PACKET".

       -show_frames
           Show information about each frame and subtitle contained in the input multimedia stream.

           The information for each single frame is printed within a dedicated section with name "FRAME" or "SUBTITLE".

       -show_log loglevel
           Show logging information from the decoder about each frame according to the value set in loglevel, (see "-loglevel").
           This option requires "-show_frames".

           The information for each log message is printed within a dedicated section with name "LOG".

       -show_streams
           Show information about each media stream contained in the input multimedia stream.

           Each media stream information is printed within a dedicated section with name "STREAM".

       -show_programs
           Show information about programs and their streams contained in the input multimedia stream.

           Each media stream information is printed within a dedicated section with name "PROGRAM_STREAM".

       -show_chapters
           Show information about chapters stored in the format.

           Each chapter is printed within a dedicated section with name "CHAPTER".

       -count_frames
           Count the number of frames per stream and report it in the corresponding stream section.

       -count_packets
           Count the number of packets per stream and report it in the corresponding stream section.

       -read_intervals read_intervals
           Read only the specified intervals. read_intervals must be a sequence of interval specifications separated by ",".
           ffprobe will seek to the interval starting point, and will continue reading from that.

           Each interval is specified by two optional parts, separated by "%".

           The first part specifies the interval start position. It is interpreted as an absolute position, or as a relative offset
           from the current position if it is preceded by the "+" character. If this first part is not specified, no seeking will
           be performed when reading this interval.

           The second part specifies the interval end position. It is interpreted as an absolute position, or as a relative offset
           from the current position if it is preceded by the "+" character. If the offset specification starts with "#", it is
           interpreted as the number of packets to read (not including the flushing packets) from the interval start. If no second
           part is specified, the program will read until the end of the input.

           Note that seeking is not accurate, thus the actual interval start point may be different from the specified position.
           Also, when an interval duration is specified, the absolute end time will be computed by adding the duration to the
           interval start point found by seeking the file, rather than to the specified start value.

           The formal syntax is given by:

                   <INTERVAL>  ::= [<START>|+<START_OFFSET>][%[<END>|+<END_OFFSET>]]
                   <INTERVALS> ::= <INTERVAL>[,<INTERVALS>]

           A few examples follow.

           •   Seek to time 10, read packets until 20 seconds after the found seek point, then seek to position "01:30" (1 minute
               and thirty seconds) and read packets until position "01:45".

                       10%+20,01:30%01:45

           •   Read only 42 packets after seeking to position "01:23":

                       01:23%+#42

           •   Read only the first 20 seconds from the start:

                       %+20

           •   Read from the start until position "02:30":

                       %02:30

       -show_private_data, -private
           Show private data, that is data depending on the format of the particular shown element.  This option is enabled by
           default, but you may need to disable it for specific uses, for example when creating XSD-compliant XML output.

       -show_program_version
           Show information related to program version.

           Version information is printed within a section with name "PROGRAM_VERSION".

       -show_library_versions
           Show information related to library versions.

           Version information for each library is printed within a section with name "LIBRARY_VERSION".

       -show_versions
           Show information related to program and library versions. This is the equivalent of setting both -show_program_version
           and -show_library_versions options.

       -show_pixel_formats
           Show information about all pixel formats supported by FFmpeg.

           Pixel format information for each format is printed within a section with name "PIXEL_FORMAT".

       -show_optional_fields value
           Some writers viz. JSON and XML, omit the printing of fields with invalid or non-applicable values, while other writers
           always print them. This option enables one to control this behaviour.  Valid values are "always"/1, "never"/0 and
           "auto"/"-1".  Default is auto.

       -bitexact
           Force bitexact output, useful to produce output which is not dependent on the specific build.

       -i input_url
           Read input_url.

       -o output_url
           Write output to output_url. If not specified, the output is sent to stdout.

WRITERS
       A writer defines the output format adopted by ffprobe, and will be used for printing all the parts of the output.

       A writer may accept one or more arguments, which specify the options to adopt. The options are specified as a list of
       key=value pairs, separated by ":".

       All writers support the following options:

       string_validation, sv
           Set string validation mode.

           The following values are accepted.

           fail
               The writer will fail immediately in case an invalid string (UTF-8) sequence or code point is found in the input.
               This is especially useful to validate input metadata.

           ignore
               Any validation error will be ignored. This will result in possibly broken output, especially with the json or xml
               writer.

           replace
               The writer will substitute invalid UTF-8 sequences or code points with the string specified with the
               string_validation_replacement.

           Default value is replace.

       string_validation_replacement, svr
           Set replacement string to use in case string_validation is set to replace.

           In case the option is not specified, the writer will assume the empty string, that is it will remove the invalid
           sequences from the input strings.

       A description of the currently available writers follows.

   default
       Default format.

       Print each section in the form:

               [SECTION]
               key1=val1
               ...
               keyN=valN
               [/SECTION]

       Metadata tags are printed as a line in the corresponding FORMAT, STREAM or PROGRAM_STREAM section, and are prefixed by the
       string "TAG:".

       A description of the accepted options follows.

       nokey, nk
           If set to 1 specify not to print the key of each field. Default value is 0.

       noprint_wrappers, nw
           If set to 1 specify not to print the section header and footer.  Default value is 0.

   compact, csv
       Compact and CSV format.

       The "csv" writer is equivalent to "compact", but supports different defaults.

       Each section is printed on a single line.  If no option is specified, the output has the form:

               section|key1=val1| ... |keyN=valN

       Metadata tags are printed in the corresponding "format" or "stream" section. A metadata tag key, if printed, is prefixed by
       the string "tag:".

       The description of the accepted options follows.

       item_sep, s
           Specify the character to use for separating fields in the output line.  It must be a single printable character, it is
           "|" by default ("," for the "csv" writer).

       nokey, nk
           If set to 1 specify not to print the key of each field. Its default value is 0 (1 for the "csv" writer).

       escape, e
           Set the escape mode to use, default to "c" ("csv" for the "csv" writer).

           It can assume one of the following values:

           c   Perform C-like escaping. Strings containing a newline (\n), carriage return (\r), a tab (\t), a form feed (\f), the
               escaping character (\) or the item separator character SEP are escaped using C-like fashioned escaping, so that a
               newline is converted to the sequence \n, a carriage return to \r, \ to \\ and the separator SEP is converted to
               \SEP.

           csv Perform CSV-like escaping, as described in RFC4180.  Strings containing a newline (\n), a carriage return (\r), a
               double quote ("), or SEP are enclosed in double-quotes.

           none
               Perform no escaping.

       print_section, p
           Print the section name at the beginning of each line if the value is 1, disable it with value set to 0. Default value is
           1.

   flat
       Flat format.

       A free-form output where each line contains an explicit key=value, such as "streams.stream.3.tags.foo=bar". The output is
       shell escaped, so it can be directly embedded in sh scripts as long as the separator character is an alphanumeric character
       or an underscore (see sep_char option).

       The description of the accepted options follows.

       sep_char, s
           Separator character used to separate the chapter, the section name, IDs and potential tags in the printed field key.

           Default value is ..

       hierarchical, h
           Specify if the section name specification should be hierarchical. If set to 1, and if there is more than one section in
           the current chapter, the section name will be prefixed by the name of the chapter. A value of 0 will disable this
           behavior.

           Default value is 1.

   ini
       INI format output.

       Print output in an INI based format.

       The following conventions are adopted:

       •   all key and values are UTF-8

       •   . is the subgroup separator

       •   newline, \t, \f, \b and the following characters are escaped

       •   \ is the escape character

       •   # is the comment indicator

       •   = is the key/value separator

       •   : is not used but usually parsed as key/value separator

       This writer accepts options as a list of key=value pairs, separated by :.

       The description of the accepted options follows.

       hierarchical, h
           Specify if the section name specification should be hierarchical. If set to 1, and if there is more than one section in
           the current chapter, the section name will be prefixed by the name of the chapter. A value of 0 will disable this
           behavior.

           Default value is 1.

   json
       JSON based format.

       Each section is printed using JSON notation.

       The description of the accepted options follows.

       compact, c
           If set to 1 enable compact output, that is each section will be printed on a single line. Default value is 0.

       For more information about JSON, see <http://www.json.org/>.

   xml
       XML based format.

       The XML output is described in the XML schema description file ffprobe.xsd installed in the FFmpeg datadir.

       An updated version of the schema can be retrieved at the url <http://www.ffmpeg.org/schema/ffprobe.xsd>, which redirects to
       the latest schema committed into the FFmpeg development source code tree.

       Note that the output issued will be compliant to the ffprobe.xsd schema only when no special global output options (unit,
       prefix, byte_binary_prefix, sexagesimal etc.) are specified.

       The description of the accepted options follows.

       fully_qualified, q
           If set to 1 specify if the output should be fully qualified. Default value is 0.  This is required for generating an XML
           file which can be validated through an XSD file.

       xsd_strict, x
           If set to 1 perform more checks for ensuring that the output is XSD compliant. Default value is 0.  This option
           automatically sets fully_qualified to 1.

       For more information about the XML format, see <https://www.w3.org/XML/>.

TIMECODE
       ffprobe supports Timecode extraction:

       •   MPEG1/2 timecode is extracted from the GOP, and is available in the video stream details (-show_streams, see timecode).

       •   MOV timecode is extracted from tmcd track, so is available in the tmcd stream metadata (-show_streams, see
           TAG:timecode).

       •   DV, GXF and AVI timecodes are available in format metadata (-show_format, see TAG:timecode).

SYNTAX
       This section documents the syntax and formats employed by the FFmpeg libraries and tools.

   Quoting and escaping
       FFmpeg adopts the following quoting and escaping mechanism, unless explicitly specified. The following rules are applied:

       •   ' and \ are special characters (respectively used for quoting and escaping). In addition to them, there might be other
           special characters depending on the specific syntax where the escaping and quoting are employed.

       •   A special character is escaped by prefixing it with a \.

       •   All characters enclosed between '' are included literally in the parsed string. The quote character ' itself cannot be
           quoted, so you may need to close the quote and escape it.

       •   Leading and trailing whitespaces, unless escaped or quoted, are removed from the parsed string.

       Note that you may need to add a second level of escaping when using the command line or a script, which depends on the
       syntax of the adopted shell language.

       The function "av_get_token" defined in libavutil/avstring.h can be used to parse a token quoted or escaped according to the
       rules defined above.

       The tool tools/ffescape in the FFmpeg source tree can be used to automatically quote or escape a string in a script.

       Examples

       •   Escape the string "Crime d'Amour" containing the "'" special character:

                   Crime d\'Amour

       •   The string above contains a quote, so the "'" needs to be escaped when quoting it:

                   'Crime d'\''Amour'

       •   Include leading or trailing whitespaces using quoting:

                   '  this string starts and ends with whitespaces  '

       •   Escaping and quoting can be mixed together:

                   ' The string '\'string\'' is a string '

       •   To include a literal \ you can use either escaping or quoting:

                   'c:\foo' can be written as c:\\foo

   Date
       The accepted syntax is:

               [(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...]]])|(HHMMSS[.m...]]]))[Z]
               now

       If the value is "now" it takes the current time.

       Time is local time unless Z is appended, in which case it is interpreted as UTC.  If the year-month-day part is not
       specified it takes the current year-month-day.

   Time duration
       There are two accepted syntaxes for expressing time duration.

               [-][<HH>:]<MM>:<SS>[.<m>...]

       HH expresses the number of hours, MM the number of minutes for a maximum of 2 digits, and SS the number of seconds for a
       maximum of 2 digits. The m at the end expresses decimal value for SS.

       or

               [-]<S>+[.<m>...][s|ms|us]

       S expresses the number of seconds, with the optional decimal part m.  The optional literal suffixes s, ms or us indicate to
       interpret the value as seconds, milliseconds or microseconds, respectively.

       In both expressions, the optional - indicates negative duration.

       Examples

       The following examples are all valid time duration:

       55  55 seconds

       0.2 0.2 seconds

       200ms
           200 milliseconds, that's 0.2s

       200000us
           200000 microseconds, that's 0.2s

       12:03:45
           12 hours, 03 minutes and 45 seconds

       23.189
           23.189 seconds

   Video size
       Specify the size of the sourced video, it may be a string of the form widthxheight, or the name of a size abbreviation.

       The following abbreviations are recognized:

       ntsc
           720x480

       pal 720x576

       qntsc
           352x240

       qpal
           352x288

       sntsc
           640x480

       spal
           768x576

       film
           352x240

       ntsc-film
           352x240

       sqcif
           128x96

       qcif
           176x144

       cif 352x288

       4cif
           704x576

       16cif
           1408x1152

       qqvga
           160x120

       qvga
           320x240

       vga 640x480

       svga
           800x600

       xga 1024x768

       uxga
           1600x1200

       qxga
           2048x1536

       sxga
           1280x1024

       qsxga
           2560x2048

       hsxga
           5120x4096

       wvga
           852x480

       wxga
           1366x768

       wsxga
           1600x1024

       wuxga
           1920x1200

       woxga
           2560x1600

       wqsxga
           3200x2048

       wquxga
           3840x2400

       whsxga
           6400x4096

       whuxga
           7680x4800

       cga 320x200

       ega 640x350

       hd480
           852x480

       hd720
           1280x720

       hd1080
           1920x1080

       2k  2048x1080

       2kflat
           1998x1080

       2kscope
           2048x858

       4k  4096x2160

       4kflat
           3996x2160

       4kscope
           4096x1716

       nhd 640x360

       hqvga
           240x160

       wqvga
           400x240

       fwqvga
           432x240

       hvga
           480x320

       qhd 960x540

       2kdci
           2048x1080

       4kdci
           4096x2160

       uhd2160
           3840x2160

       uhd4320
           7680x4320

   Video rate
       Specify the frame rate of a video, expressed as the number of frames generated per second. It has to be a string in the
       format frame_rate_num/frame_rate_den, an integer number, a float number or a valid video frame rate abbreviation.

       The following abbreviations are recognized:

       ntsc
           30000/1001

       pal 25/1

       qntsc
           30000/1001

       qpal
           25/1

       sntsc
           30000/1001

       spal
           25/1

       film
           24/1

       ntsc-film
           24000/1001

   Ratio
       A ratio can be expressed as an expression, or in the form numerator:denominator.

       Note that a ratio with infinite (1/0) or negative value is considered valid, so you should check on the returned value if
       you want to exclude those values.

       The undefined value can be expressed using the "0:0" string.

   Color
       It can be the name of a color as defined below (case insensitive match) or a "[0x|#]RRGGBB[AA]" sequence, possibly followed
       by @ and a string representing the alpha component.

       The alpha component may be a string composed by "0x" followed by an hexadecimal number or a decimal number between 0.0 and
       1.0, which represents the opacity value (0x00 or 0.0 means completely transparent, 0xff or 1.0 completely opaque). If the
       alpha component is not specified then 0xff is assumed.

       The string random will result in a random color.

       The following names of colors are recognized:

       AliceBlue
           0xF0F8FF

       AntiqueWhite
           0xFAEBD7

       Aqua
           0x00FFFF

       Aquamarine
           0x7FFFD4

       Azure
           0xF0FFFF

       Beige
           0xF5F5DC

       Bisque
           0xFFE4C4

       Black
           0x000000

       BlanchedAlmond
           0xFFEBCD

       Blue
           0x0000FF

       BlueViolet
           0x8A2BE2

       Brown
           0xA52A2A

       BurlyWood
           0xDEB887

       CadetBlue
           0x5F9EA0

       Chartreuse
           0x7FFF00

       Chocolate
           0xD2691E

       Coral
           0xFF7F50

       CornflowerBlue
           0x6495ED

       Cornsilk
           0xFFF8DC

       Crimson
           0xDC143C

       Cyan
           0x00FFFF

       DarkBlue
           0x00008B

       DarkCyan
           0x008B8B

       DarkGoldenRod
           0xB8860B

       DarkGray
           0xA9A9A9

       DarkGreen
           0x006400

       DarkKhaki
           0xBDB76B

       DarkMagenta
           0x8B008B

       DarkOliveGreen
           0x556B2F

       Darkorange
           0xFF8C00

       DarkOrchid
           0x9932CC

       DarkRed
           0x8B0000

       DarkSalmon
           0xE9967A

       DarkSeaGreen
           0x8FBC8F

       DarkSlateBlue
           0x483D8B

       DarkSlateGray
           0x2F4F4F

       DarkTurquoise
           0x00CED1

       DarkViolet
           0x9400D3

       DeepPink
           0xFF1493

       DeepSkyBlue
           0x00BFFF

       DimGray
           0x696969

       DodgerBlue
           0x1E90FF

       FireBrick
           0xB22222

       FloralWhite
           0xFFFAF0

       ForestGreen
           0x228B22

       Fuchsia
           0xFF00FF

       Gainsboro
           0xDCDCDC

       GhostWhite
           0xF8F8FF

       Gold
           0xFFD700

       GoldenRod
           0xDAA520

       Gray
           0x808080

       Green
           0x008000

       GreenYellow
           0xADFF2F

       HoneyDew
           0xF0FFF0

       HotPink
           0xFF69B4

       IndianRed
           0xCD5C5C

       Indigo
           0x4B0082

       Ivory
           0xFFFFF0

       Khaki
           0xF0E68C

       Lavender
           0xE6E6FA

       LavenderBlush
           0xFFF0F5

       LawnGreen
           0x7CFC00

       LemonChiffon
           0xFFFACD

       LightBlue
           0xADD8E6

       LightCoral
           0xF08080

       LightCyan
           0xE0FFFF

       LightGoldenRodYellow
           0xFAFAD2

       LightGreen
           0x90EE90

       LightGrey
           0xD3D3D3

       LightPink
           0xFFB6C1

       LightSalmon
           0xFFA07A

       LightSeaGreen
           0x20B2AA

       LightSkyBlue
           0x87CEFA

       LightSlateGray
           0x778899

       LightSteelBlue
           0xB0C4DE

       LightYellow
           0xFFFFE0

       Lime
           0x00FF00

       LimeGreen
           0x32CD32

       Linen
           0xFAF0E6

       Magenta
           0xFF00FF

       Maroon
           0x800000

       MediumAquaMarine
           0x66CDAA

       MediumBlue
           0x0000CD

       MediumOrchid
           0xBA55D3

       MediumPurple
           0x9370D8

       MediumSeaGreen
           0x3CB371

       MediumSlateBlue
           0x7B68EE

       MediumSpringGreen
           0x00FA9A

       MediumTurquoise
           0x48D1CC

       MediumVioletRed
           0xC71585

       MidnightBlue
           0x191970

       MintCream
           0xF5FFFA

       MistyRose
           0xFFE4E1

       Moccasin
           0xFFE4B5

       NavajoWhite
           0xFFDEAD

       Navy
           0x000080

       OldLace
           0xFDF5E6

       Olive
           0x808000

       OliveDrab
           0x6B8E23

       Orange
           0xFFA500

       OrangeRed
           0xFF4500

       Orchid
           0xDA70D6

       PaleGoldenRod
           0xEEE8AA

       PaleGreen
           0x98FB98

       PaleTurquoise
           0xAFEEEE

       PaleVioletRed
           0xD87093

       PapayaWhip
           0xFFEFD5

       PeachPuff
           0xFFDAB9

       Peru
           0xCD853F

       Pink
           0xFFC0CB

       Plum
           0xDDA0DD

       PowderBlue
           0xB0E0E6

       Purple
           0x800080

       Red 0xFF0000

       RosyBrown
           0xBC8F8F

       RoyalBlue
           0x4169E1

       SaddleBrown
           0x8B4513

       Salmon
           0xFA8072

       SandyBrown
           0xF4A460

       SeaGreen
           0x2E8B57

       SeaShell
           0xFFF5EE

       Sienna
           0xA0522D

       Silver
           0xC0C0C0

       SkyBlue
           0x87CEEB

       SlateBlue
           0x6A5ACD

       SlateGray
           0x708090

       Snow
           0xFFFAFA

       SpringGreen
           0x00FF7F

       SteelBlue
           0x4682B4

       Tan 0xD2B48C

       Teal
           0x008080

       Thistle
           0xD8BFD8

       Tomato
           0xFF6347

       Turquoise
           0x40E0D0

       Violet
           0xEE82EE

       Wheat
           0xF5DEB3

       White
           0xFFFFFF

       WhiteSmoke
           0xF5F5F5

       Yellow
           0xFFFF00

       YellowGreen
           0x9ACD32

   Channel Layout
       A channel layout specifies the spatial disposition of the channels in a multi-channel audio stream. To specify a channel
       layout, FFmpeg makes use of a special syntax.

       Individual channels are identified by an id, as given by the table below:

       FL  front left

       FR  front right

       FC  front center

       LFE low frequency

       BL  back left

       BR  back right

       FLC front left-of-center

       FRC front right-of-center

       BC  back center

       SL  side left

       SR  side right

       TC  top center

       TFL top front left

       TFC top front center

       TFR top front right

       TBL top back left

       TBC top back center

       TBR top back right

       DL  downmix left

       DR  downmix right

       WL  wide left

       WR  wide right

       SDL surround direct left

       SDR surround direct right

       LFE2
           low frequency 2

       Standard channel layout compositions can be specified by using the following identifiers:

       mono
           FC

       stereo
           FL+FR

       2.1 FL+FR+LFE

       3.0 FL+FR+FC

       3.0(back)
           FL+FR+BC

       4.0 FL+FR+FC+BC

       quad
           FL+FR+BL+BR

       quad(side)
           FL+FR+SL+SR

       3.1 FL+FR+FC+LFE

       5.0 FL+FR+FC+BL+BR

       5.0(side)
           FL+FR+FC+SL+SR

       4.1 FL+FR+FC+LFE+BC

       5.1 FL+FR+FC+LFE+BL+BR

       5.1(side)
           FL+FR+FC+LFE+SL+SR

       6.0 FL+FR+FC+BC+SL+SR

       6.0(front)
           FL+FR+FLC+FRC+SL+SR

       hexagonal
           FL+FR+FC+BL+BR+BC

       6.1 FL+FR+FC+LFE+BC+SL+SR

       6.1 FL+FR+FC+LFE+BL+BR+BC

       6.1(front)
           FL+FR+LFE+FLC+FRC+SL+SR

       7.0 FL+FR+FC+BL+BR+SL+SR

       7.0(front)
           FL+FR+FC+FLC+FRC+SL+SR

       7.1 FL+FR+FC+LFE+BL+BR+SL+SR

       7.1(wide)
           FL+FR+FC+LFE+BL+BR+FLC+FRC

       7.1(wide-side)
           FL+FR+FC+LFE+FLC+FRC+SL+SR

       octagonal
           FL+FR+FC+BL+BR+BC+SL+SR

       hexadecagonal
           FL+FR+FC+BL+BR+BC+SL+SR+WL+WR+TBL+TBR+TBC+TFC+TFL+TFR

       downmix
           DL+DR

       22.2
           FL+FR+FC+LFE+BL+BR+FLC+FRC+BC+SL+SR+TC+TFL+TFC+TFR+TBL+TBC+TBR+LFE2+TSL+TSR+BFC+BFL+BFR

       A custom channel layout can be specified as a sequence of terms, separated by '+'.  Each term can be:

       •   the name of a single channel (e.g. FL, FR, FC, LFE, etc.), each optionally containing a custom name after a '@', (e.g.
           FL@Left, FR@Right, FC@Center, LFE@Low_Frequency, etc.)

       A standard channel layout can be specified by the following:

       •   the name of a single channel (e.g. FL, FR, FC, LFE, etc.)

       •   the name of a standard channel layout (e.g. mono, stereo, 4.0, quad, 5.0, etc.)

       •   a number of channels, in decimal, followed by 'c', yielding the default channel layout for that number of channels (see
           the function "av_channel_layout_default"). Note that not all channel counts have a default layout.

       •   a number of channels, in decimal, followed by 'C', yielding an unknown channel layout with the specified number of
           channels. Note that not all channel layout specification strings support unknown channel layouts.

       •   a channel layout mask, in hexadecimal starting with "0x" (see the "AV_CH_*" macros in libavutil/channel_layout.h.

       Before libavutil version 53 the trailing character "c" to specify a number of channels was optional, but now it is required,
       while a channel layout mask can also be specified as a decimal number (if and only if not followed by "c" or "C").

       See also the function "av_channel_layout_from_string" defined in libavutil/channel_layout.h.

EXPRESSION EVALUATION
       When evaluating an arithmetic expression, FFmpeg uses an internal formula evaluator, implemented through the
       libavutil/eval.h interface.

       An expression may contain unary, binary operators, constants, and functions.

       Two expressions expr1 and expr2 can be combined to form another expression "expr1;expr2".  expr1 and expr2 are evaluated in
       turn, and the new expression evaluates to the value of expr2.

       The following binary operators are available: "+", "-", "*", "/", "^".

       The following unary operators are available: "+", "-".

       The following functions are available:

       abs(x)
           Compute absolute value of x.

       acos(x)
           Compute arccosine of x.

       asin(x)
           Compute arcsine of x.

       atan(x)
           Compute arctangent of x.

       atan2(x, y)
           Compute principal value of the arc tangent of y/x.

       between(x, min, max)
           Return 1 if x is greater than or equal to min and lesser than or equal to max, 0 otherwise.

       bitand(x, y)
       bitor(x, y)
           Compute bitwise and/or operation on x and y.

           The results of the evaluation of x and y are converted to integers before executing the bitwise operation.

           Note that both the conversion to integer and the conversion back to floating point can lose precision. Beware of
           unexpected results for large numbers (usually 2^53 and larger).

       ceil(expr)
           Round the value of expression expr upwards to the nearest integer. For example, "ceil(1.5)" is "2.0".

       clip(x, min, max)
           Return the value of x clipped between min and max.

       cos(x)
           Compute cosine of x.

       cosh(x)
           Compute hyperbolic cosine of x.

       eq(x, y)
           Return 1 if x and y are equivalent, 0 otherwise.

       exp(x)
           Compute exponential of x (with base "e", the Euler's number).

       floor(expr)
           Round the value of expression expr downwards to the nearest integer. For example, "floor(-1.5)" is "-2.0".

       gauss(x)
           Compute Gauss function of x, corresponding to "exp(-x*x/2) / sqrt(2*PI)".

       gcd(x, y)
           Return the greatest common divisor of x and y. If both x and y are 0 or either or both are less than zero then behavior
           is undefined.

       gt(x, y)
           Return 1 if x is greater than y, 0 otherwise.

       gte(x, y)
           Return 1 if x is greater than or equal to y, 0 otherwise.

       hypot(x, y)
           This function is similar to the C function with the same name; it returns "sqrt(x*x + y*y)", the length of the
           hypotenuse of a right triangle with sides of length x and y, or the distance of the point (x, y) from the origin.

       if(x, y)
           Evaluate x, and if the result is non-zero return the result of the evaluation of y, return 0 otherwise.

       if(x, y, z)
           Evaluate x, and if the result is non-zero return the evaluation result of y, otherwise the evaluation result of z.

       ifnot(x, y)
           Evaluate x, and if the result is zero return the result of the evaluation of y, return 0 otherwise.

       ifnot(x, y, z)
           Evaluate x, and if the result is zero return the evaluation result of y, otherwise the evaluation result of z.

       isinf(x)
           Return 1.0 if x is +/-INFINITY, 0.0 otherwise.

       isnan(x)
           Return 1.0 if x is NAN, 0.0 otherwise.

       ld(var)
           Load the value of the internal variable with number var, which was previously stored with st(var, expr).  The function
           returns the loaded value.

       lerp(x, y, z)
           Return linear interpolation between x and y by amount of z.

       log(x)
           Compute natural logarithm of x.

       lt(x, y)
           Return 1 if x is lesser than y, 0 otherwise.

       lte(x, y)
           Return 1 if x is lesser than or equal to y, 0 otherwise.

       max(x, y)
           Return the maximum between x and y.

       min(x, y)
           Return the minimum between x and y.

       mod(x, y)
           Compute the remainder of division of x by y.

       not(expr)
           Return 1.0 if expr is zero, 0.0 otherwise.

       pow(x, y)
           Compute the power of x elevated y, it is equivalent to "(x)^(y)".

       print(t)
       print(t, l)
           Print the value of expression t with loglevel l. If l is not specified then a default log level is used.  Returns the
           value of the expression printed.

           Prints t with loglevel l

       random(x)
           Return a pseudo random value between 0.0 and 1.0. x is the index of the internal variable which will be used to save the
           seed/state.

       root(expr, max)
           Find an input value for which the function represented by expr with argument ld(0) is 0 in the interval 0..max.

           The expression in expr must denote a continuous function or the result is undefined.

           ld(0) is used to represent the function input value, which means that the given expression will be evaluated multiple
           times with various input values that the expression can access through ld(0). When the expression evaluates to 0 then
           the corresponding input value will be returned.

       round(expr)
           Round the value of expression expr to the nearest integer. For example, "round(1.5)" is "2.0".

       sgn(x)
           Compute sign of x.

       sin(x)
           Compute sine of x.

       sinh(x)
           Compute hyperbolic sine of x.

       sqrt(expr)
           Compute the square root of expr. This is equivalent to "(expr)^.5".

       squish(x)
           Compute expression "1/(1 + exp(4*x))".

       st(var, expr)
           Store the value of the expression expr in an internal variable. var specifies the number of the variable where to store
           the value, and it is a value ranging from 0 to 9. The function returns the value stored in the internal variable.  Note,
           Variables are currently not shared between expressions.

       tan(x)
           Compute tangent of x.

       tanh(x)
           Compute hyperbolic tangent of x.

       taylor(expr, x)
       taylor(expr, x, id)
           Evaluate a Taylor series at x, given an expression representing the "ld(id)"-th derivative of a function at 0.

           When the series does not converge the result is undefined.

           ld(id) is used to represent the derivative order in expr, which means that the given expression will be evaluated
           multiple times with various input values that the expression can access through "ld(id)". If id is not specified then 0
           is assumed.

           Note, when you have the derivatives at y instead of 0, "taylor(expr, x-y)" can be used.

       time(0)
           Return the current (wallclock) time in seconds.

       trunc(expr)
           Round the value of expression expr towards zero to the nearest integer. For example, "trunc(-1.5)" is "-1.0".

       while(cond, expr)
           Evaluate expression expr while the expression cond is non-zero, and returns the value of the last expr evaluation, or
           NAN if cond was always false.

       The following constants are available:

       PI  area of the unit disc, approximately 3.14

       E   exp(1) (Euler's number), approximately 2.718

       PHI golden ratio (1+sqrt(5))/2, approximately 1.618

       Assuming that an expression is considered "true" if it has a non-zero value, note that:

       "*" works like AND

       "+" works like OR

       For example the construct:

               if (A AND B) then C

       is equivalent to:

               if(A*B, C)

       In your C code, you can extend the list of unary and binary functions, and define recognized constants, so that they are
       available for your expressions.

       The evaluator also recognizes the International System unit prefixes.  If 'i' is appended after the prefix, binary prefixes
       are used, which are based on powers of 1024 instead of powers of 1000.  The 'B' postfix multiplies the value by 8, and can
       be appended after a unit prefix or used alone. This allows using for example 'KB', 'MiB', 'G' and 'B' as number postfix.

       The list of available International System prefixes follows, with indication of the corresponding powers of 10 and of 2.

       y   10^-24 / 2^-80

       z   10^-21 / 2^-70

       a   10^-18 / 2^-60

       f   10^-15 / 2^-50

       p   10^-12 / 2^-40

       n   10^-9 / 2^-30

       u   10^-6 / 2^-20

       m   10^-3 / 2^-10

       c   10^-2

       d   10^-1

       h   10^2

       k   10^3 / 2^10

       K   10^3 / 2^10

       M   10^6 / 2^20

       G   10^9 / 2^30

       T   10^12 / 2^40

       P   10^15 / 2^40

       E   10^18 / 2^50

       Z   10^21 / 2^60

       Y   10^24 / 2^70

CODEC OPTIONS
       libavcodec provides some generic global options, which can be set on all the encoders and decoders. In addition each codec
       may support so-called private options, which are specific for a given codec.

       Sometimes, a global option may only affect a specific kind of codec, and may be nonsensical or ignored by another, so you
       need to be aware of the meaning of the specified options. Also some options are meant only for decoding or encoding.

       Options may be set by specifying -option value in the FFmpeg tools, or by setting the value explicitly in the
       "AVCodecContext" options or using the libavutil/opt.h API for programmatic use.

       The list of supported options follow:

       b integer (encoding,audio,video)
           Set bitrate in bits/s. Default value is 200K.

       ab integer (encoding,audio)
           Set audio bitrate (in bits/s). Default value is 128K.

       bt integer (encoding,video)
           Set video bitrate tolerance (in bits/s). In 1-pass mode, bitrate tolerance specifies how far ratecontrol is willing to
           deviate from the target average bitrate value. This is not related to min/max bitrate. Lowering tolerance too much has
           an adverse effect on quality.

       flags flags (decoding/encoding,audio,video,subtitles)
           Set generic flags.

           Possible values:

           mv4 Use four motion vector by macroblock (mpeg4).

           qpel
               Use 1/4 pel motion compensation.

           loop
               Use loop filter.

           qscale
               Use fixed qscale.

           pass1
               Use internal 2pass ratecontrol in first pass mode.

           pass2
               Use internal 2pass ratecontrol in second pass mode.

           gray
               Only decode/encode grayscale.

           psnr
               Set error[?] variables during encoding.

           truncated
               Input bitstream might be randomly truncated.

           drop_changed
               Don't output frames whose parameters differ from first decoded frame in stream.  Error AVERROR_INPUT_CHANGED is
               returned when a frame is dropped.

           ildct
               Use interlaced DCT.

           low_delay
               Force low delay.

           global_header
               Place global headers in extradata instead of every keyframe.

           bitexact
               Only write platform-, build- and time-independent data. (except (I)DCT).  This ensures that file and data checksums
               are reproducible and match between platforms. Its primary use is for regression testing.

           aic Apply H263 advanced intra coding / mpeg4 ac prediction.

           ilme
               Apply interlaced motion estimation.

           cgop
               Use closed gop.

           output_corrupt
               Output even potentially corrupted frames.

       time_base rational number
           Set codec time base.

           It is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented. For fixed-fps
           content, timebase should be "1 / frame_rate" and timestamp increments should be identically 1.

       g integer (encoding,video)
           Set the group of picture (GOP) size. Default value is 12.

       ar integer (decoding/encoding,audio)
           Set audio sampling rate (in Hz).

       ac integer (decoding/encoding,audio)
           Set number of audio channels.

       cutoff integer (encoding,audio)
           Set cutoff bandwidth. (Supported only by selected encoders, see their respective documentation sections.)

       frame_size integer (encoding,audio)
           Set audio frame size.

           Each submitted frame except the last must contain exactly frame_size samples per channel. May be 0 when the codec has
           CODEC_CAP_VARIABLE_FRAME_SIZE set, in that case the frame size is not restricted. It is set by some decoders to indicate
           constant frame size.

       frame_number integer
           Set the frame number.

       delay integer
       qcomp float (encoding,video)
           Set video quantizer scale compression (VBR). It is used as a constant in the ratecontrol equation. Recommended range for
           default rc_eq: 0.0-1.0.

       qblur float (encoding,video)
           Set video quantizer scale blur (VBR).

       qmin integer (encoding,video)
           Set min video quantizer scale (VBR). Must be included between -1 and 69, default value is 2.

       qmax integer (encoding,video)
           Set max video quantizer scale (VBR). Must be included between -1 and 1024, default value is 31.

       qdiff integer (encoding,video)
           Set max difference between the quantizer scale (VBR).

       bf integer (encoding,video)
           Set max number of B frames between non-B-frames.

           Must be an integer between -1 and 16. 0 means that B-frames are disabled. If a value of -1 is used, it will choose an
           automatic value depending on the encoder.

           Default value is 0.

       b_qfactor float (encoding,video)
           Set qp factor between P and B frames.

       codec_tag integer
       bug flags (decoding,video)
           Workaround not auto detected encoder bugs.

           Possible values:

           autodetect
           xvid_ilace
               Xvid interlacing bug (autodetected if fourcc==XVIX)

           ump4
               (autodetected if fourcc==UMP4)

           no_padding
               padding bug (autodetected)

           amv
           qpel_chroma
           std_qpel
               old standard qpel (autodetected per fourcc/version)

           qpel_chroma2
           direct_blocksize
               direct-qpel-blocksize bug (autodetected per fourcc/version)

           edge
               edge padding bug (autodetected per fourcc/version)

           hpel_chroma
           dc_clip
           ms  Workaround various bugs in microsoft broken decoders.

           trunc
               trancated frames

       strict integer (decoding/encoding,audio,video)
           Specify how strictly to follow the standards.

           Possible values:

           very
               strictly conform to an older more strict version of the spec or reference software

           strict
               strictly conform to all the things in the spec no matter what consequences

           normal
           unofficial
               allow unofficial extensions

           experimental
               allow non standardized experimental things, experimental (unfinished/work in progress/not well tested) decoders and
               encoders.  Note: experimental decoders can pose a security risk, do not use this for decoding untrusted input.

       b_qoffset float (encoding,video)
           Set QP offset between P and B frames.

       err_detect flags (decoding,audio,video)
           Set error detection flags.

           Possible values:

           crccheck
               verify embedded CRCs

           bitstream
               detect bitstream specification deviations

           buffer
               detect improper bitstream length

           explode
               abort decoding on minor error detection

           ignore_err
               ignore decoding errors, and continue decoding.  This is useful if you want to analyze the content of a video and
               thus want everything to be decoded no matter what. This option will not result in a video that is pleasing to watch
               in case of errors.

           careful
               consider things that violate the spec and have not been seen in the wild as errors

           compliant
               consider all spec non compliancies as errors

           aggressive
               consider things that a sane encoder should not do as an error

       has_b_frames integer
       block_align integer
       rc_override_count integer
       maxrate integer (encoding,audio,video)
           Set max bitrate tolerance (in bits/s). Requires bufsize to be set.

       minrate integer (encoding,audio,video)
           Set min bitrate tolerance (in bits/s). Most useful in setting up a CBR encode. It is of little use elsewise.

       bufsize integer (encoding,audio,video)
           Set ratecontrol buffer size (in bits).

       i_qfactor float (encoding,video)
           Set QP factor between P and I frames.

       i_qoffset float (encoding,video)
           Set QP offset between P and I frames.

       dct integer (encoding,video)
           Set DCT algorithm.

           Possible values:

           auto
               autoselect a good one (default)

           fastint
               fast integer

           int accurate integer

           mmx
           altivec
           faan
               floating point AAN DCT

       lumi_mask float (encoding,video)
           Compress bright areas stronger than medium ones.

       tcplx_mask float (encoding,video)
           Set temporal complexity masking.

       scplx_mask float (encoding,video)
           Set spatial complexity masking.

       p_mask float (encoding,video)
           Set inter masking.

       dark_mask float (encoding,video)
           Compress dark areas stronger than medium ones.

       idct integer (decoding/encoding,video)
           Select IDCT implementation.

           Possible values:

           auto
           int
           simple
           simplemmx
           simpleauto
               Automatically pick a IDCT compatible with the simple one

           arm
           altivec
           sh4
           simplearm
           simplearmv5te
           simplearmv6
           simpleneon
           xvid
           faani
               floating point AAN IDCT

       slice_count integer
       ec flags (decoding,video)
           Set error concealment strategy.

           Possible values:

           guess_mvs
               iterative motion vector (MV) search (slow)

           deblock
               use strong deblock filter for damaged MBs

           favor_inter
               favor predicting from the previous frame instead of the current

       bits_per_coded_sample integer
       aspect rational number (encoding,video)
           Set sample aspect ratio.

       sar rational number (encoding,video)
           Set sample aspect ratio. Alias to aspect.

       debug flags (decoding/encoding,audio,video,subtitles)
           Print specific debug info.

           Possible values:

           pict
               picture info

           rc  rate control

           bitstream
           mb_type
               macroblock (MB) type

           qp  per-block quantization parameter (QP)

           dct_coeff
           green_metadata
               display complexity metadata for the upcoming frame, GoP or for a given duration.

           skip
           startcode
           er  error recognition

           mmco
               memory management control operations (H.264)

           bugs
           buffers
               picture buffer allocations

           thread_ops
               threading operations

           nomc
               skip motion compensation

       cmp integer (encoding,video)
           Set full pel me compare function.

           Possible values:

           sad sum of absolute differences, fast (default)

           sse sum of squared errors

           satd
               sum of absolute Hadamard transformed differences

           dct sum of absolute DCT transformed differences

           psnr
               sum of squared quantization errors (avoid, low quality)

           bit number of bits needed for the block

           rd  rate distortion optimal, slow

           zero
               0

           vsad
               sum of absolute vertical differences

           vsse
               sum of squared vertical differences

           nsse
               noise preserving sum of squared differences

           w53 5/3 wavelet, only used in snow

           w97 9/7 wavelet, only used in snow

           dctmax
           chroma
       subcmp integer (encoding,video)
           Set sub pel me compare function.

           Possible values:

           sad sum of absolute differences, fast (default)

           sse sum of squared errors

           satd
               sum of absolute Hadamard transformed differences

           dct sum of absolute DCT transformed differences

           psnr
               sum of squared quantization errors (avoid, low quality)

           bit number of bits needed for the block

           rd  rate distortion optimal, slow

           zero
               0

           vsad
               sum of absolute vertical differences

           vsse
               sum of squared vertical differences

           nsse
               noise preserving sum of squared differences

           w53 5/3 wavelet, only used in snow

           w97 9/7 wavelet, only used in snow

           dctmax
           chroma
       mbcmp integer (encoding,video)
           Set macroblock compare function.

           Possible values:

           sad sum of absolute differences, fast (default)

           sse sum of squared errors

           satd
               sum of absolute Hadamard transformed differences

           dct sum of absolute DCT transformed differences

           psnr
               sum of squared quantization errors (avoid, low quality)

           bit number of bits needed for the block

           rd  rate distortion optimal, slow

           zero
               0

           vsad
               sum of absolute vertical differences

           vsse
               sum of squared vertical differences

           nsse
               noise preserving sum of squared differences

           w53 5/3 wavelet, only used in snow

           w97 9/7 wavelet, only used in snow

           dctmax
           chroma
       ildctcmp integer (encoding,video)
           Set interlaced dct compare function.

           Possible values:

           sad sum of absolute differences, fast (default)

           sse sum of squared errors

           satd
               sum of absolute Hadamard transformed differences

           dct sum of absolute DCT transformed differences

           psnr
               sum of squared quantization errors (avoid, low quality)

           bit number of bits needed for the block

           rd  rate distortion optimal, slow

           zero
               0

           vsad
               sum of absolute vertical differences

           vsse
               sum of squared vertical differences

           nsse
               noise preserving sum of squared differences

           w53 5/3 wavelet, only used in snow

           w97 9/7 wavelet, only used in snow

           dctmax
           chroma
       dia_size integer (encoding,video)
           Set diamond type & size for motion estimation.

           (1024, INT_MAX)
               full motion estimation(slowest)

           (768, 1024]
               umh motion estimation

           (512, 768]
               hex motion estimation

           (256, 512]
               l2s diamond motion estimation

           [2,256]
               var diamond motion estimation

           (-1,  2)
               small diamond motion estimation

           -1  funny diamond motion estimation

           (INT_MIN, -1)
               sab diamond motion estimation

       last_pred integer (encoding,video)
           Set amount of motion predictors from the previous frame.

       precmp integer (encoding,video)
           Set pre motion estimation compare function.

           Possible values:

           sad sum of absolute differences, fast (default)

           sse sum of squared errors

           satd
               sum of absolute Hadamard transformed differences

           dct sum of absolute DCT transformed differences

           psnr
               sum of squared quantization errors (avoid, low quality)

           bit number of bits needed for the block

           rd  rate distortion optimal, slow

           zero
               0

           vsad
               sum of absolute vertical differences

           vsse
               sum of squared vertical differences

           nsse
               noise preserving sum of squared differences

           w53 5/3 wavelet, only used in snow

           w97 9/7 wavelet, only used in snow

           dctmax
           chroma
       pre_dia_size integer (encoding,video)
           Set diamond type & size for motion estimation pre-pass.

       subq integer (encoding,video)
           Set sub pel motion estimation quality.

       me_range integer (encoding,video)
           Set limit motion vectors range (1023 for DivX player).

       global_quality integer (encoding,audio,video)
       slice_flags integer
       mbd integer (encoding,video)
           Set macroblock decision algorithm (high quality mode).

           Possible values:

           simple
               use mbcmp (default)

           bits
               use fewest bits

           rd  use best rate distortion

       rc_init_occupancy integer (encoding,video)
           Set number of bits which should be loaded into the rc buffer before decoding starts.

       flags2 flags (decoding/encoding,audio,video,subtitles)
           Possible values:

           fast
               Allow non spec compliant speedup tricks.

           noout
               Skip bitstream encoding.

           ignorecrop
               Ignore cropping information from sps.

           local_header
               Place global headers at every keyframe instead of in extradata.

           chunks
               Frame data might be split into multiple chunks.

           showall
               Show all frames before the first keyframe.

           export_mvs
               Export motion vectors into frame side-data (see "AV_FRAME_DATA_MOTION_VECTORS") for codecs that support it. See also
               doc/examples/export_mvs.c.

           skip_manual
               Do not skip samples and export skip information as frame side data.

           ass_ro_flush_noop
               Do not reset ASS ReadOrder field on flush.

       export_side_data flags (decoding/encoding,audio,video,subtitles)
           Possible values:

           mvs Export motion vectors into frame side-data (see "AV_FRAME_DATA_MOTION_VECTORS") for codecs that support it. See also
               doc/examples/export_mvs.c.

           prft
               Export encoder Producer Reference Time into packet side-data (see "AV_PKT_DATA_PRFT") for codecs that support it.

           venc_params
               Export video encoding parameters through frame side data (see "AV_FRAME_DATA_VIDEO_ENC_PARAMS") for codecs that
               support it. At present, those are H.264 and VP9.

           film_grain
               Export film grain parameters through frame side data (see "AV_FRAME_DATA_FILM_GRAIN_PARAMS").  Supported at present
               by AV1 decoders.

       threads integer (decoding/encoding,video)
           Set the number of threads to be used, in case the selected codec implementation supports multi-threading.

           Possible values:

           auto, 0
               automatically select the number of threads to set

           Default value is auto.

       dc integer (encoding,video)
           Set intra_dc_precision.

       nssew integer (encoding,video)
           Set nsse weight.

       skip_top integer (decoding,video)
           Set number of macroblock rows at the top which are skipped.

       skip_bottom integer (decoding,video)
           Set number of macroblock rows at the bottom which are skipped.

       profile integer (encoding,audio,video)
           Set encoder codec profile. Default value is unknown. Encoder specific profiles are documented in the relevant encoder
           documentation.

       level integer (encoding,audio,video)
           Possible values:

           unknown
       lowres integer (decoding,audio,video)
           Decode at 1= 1/2, 2=1/4, 3=1/8 resolutions.

       mblmin integer (encoding,video)
           Set min macroblock lagrange factor (VBR).

       mblmax integer (encoding,video)
           Set max macroblock lagrange factor (VBR).

       skip_loop_filter integer (decoding,video)
       skip_idct        integer (decoding,video)
       skip_frame       integer (decoding,video)
           Make decoder discard processing depending on the frame type selected by the option value.

           skip_loop_filter skips frame loop filtering, skip_idct skips frame IDCT/dequantization, skip_frame skips decoding.

           Possible values:

           none
               Discard no frame.

           default
               Discard useless frames like 0-sized frames.

           noref
               Discard all non-reference frames.

           bidir
               Discard all bidirectional frames.

           nokey
               Discard all frames excepts keyframes.

           nointra
               Discard all frames except I frames.

           all Discard all frames.

           Default value is default.

       bidir_refine integer (encoding,video)
           Refine the two motion vectors used in bidirectional macroblocks.

       keyint_min integer (encoding,video)
           Set minimum interval between IDR-frames.

       refs integer (encoding,video)
           Set reference frames to consider for motion compensation.

       trellis integer (encoding,audio,video)
           Set rate-distortion optimal quantization.

       mv0_threshold integer (encoding,video)
       compression_level integer (encoding,audio,video)
       bits_per_raw_sample integer
       channel_layout integer (decoding/encoding,audio)
           Possible values:

       request_channel_layout integer (decoding,audio)
           Possible values:

       rc_max_vbv_use float (encoding,video)
       rc_min_vbv_use float (encoding,video)
       ticks_per_frame integer (decoding/encoding,audio,video)
       color_primaries integer (decoding/encoding,video)
           Possible values:

           bt709
               BT.709

           bt470m
               BT.470 M

           bt470bg
               BT.470 BG

           smpte170m
               SMPTE 170 M

           smpte240m
               SMPTE 240 M

           film
               Film

           bt2020
               BT.2020

           smpte428
           smpte428_1
               SMPTE ST 428-1

           smpte431
               SMPTE 431-2

           smpte432
               SMPTE 432-1

           jedec-p22
               JEDEC P22

       color_trc integer (decoding/encoding,video)
           Possible values:

           bt709
               BT.709

           gamma22
               BT.470 M

           gamma28
               BT.470 BG

           smpte170m
               SMPTE 170 M

           smpte240m
               SMPTE 240 M

           linear
               Linear

           log
           log100
               Log

           log_sqrt
           log316
               Log square root

           iec61966_2_4
           iec61966-2-4
               IEC 61966-2-4

           bt1361
           bt1361e
               BT.1361

           iec61966_2_1
           iec61966-2-1
               IEC 61966-2-1

           bt2020_10
           bt2020_10bit
               BT.2020 - 10 bit

           bt2020_12
           bt2020_12bit
               BT.2020 - 12 bit

           smpte2084
               SMPTE ST 2084

           smpte428
           smpte428_1
               SMPTE ST 428-1

           arib-std-b67
               ARIB STD-B67

       colorspace integer (decoding/encoding,video)
           Possible values:

           rgb RGB

           bt709
               BT.709

           fcc FCC

           bt470bg
               BT.470 BG

           smpte170m
               SMPTE 170 M

           smpte240m
               SMPTE 240 M

           ycocg
               YCOCG

           bt2020nc
           bt2020_ncl
               BT.2020 NCL

           bt2020c
           bt2020_cl
               BT.2020 CL

           smpte2085
               SMPTE 2085

           chroma-derived-nc
               Chroma-derived NCL

           chroma-derived-c
               Chroma-derived CL

           ictcp
               ICtCp

       color_range integer (decoding/encoding,video)
           If used as input parameter, it serves as a hint to the decoder, which color_range the input has.  Possible values:

           tv
           mpeg
               MPEG (219*2^(n-8))

           pc
           jpeg
               JPEG (2^n-1)

       chroma_sample_location integer (decoding/encoding,video)
           Possible values:

           left
           center
           topleft
           top
           bottomleft
           bottom
       log_level_offset integer
           Set the log level offset.

       slices integer (encoding,video)
           Number of slices, used in parallelized encoding.

       thread_type flags (decoding/encoding,video)
           Select which multithreading methods to use.

           Use of frame will increase decoding delay by one frame per thread, so clients which cannot provide future frames should
           not use it.

           Possible values:

           slice
               Decode more than one part of a single frame at once.

               Multithreading using slices works only when the video was encoded with slices.

           frame
               Decode more than one frame at once.

           Default value is slice+frame.

       audio_service_type integer (encoding,audio)
           Set audio service type.

           Possible values:

           ma  Main Audio Service

           ef  Effects

           vi  Visually Impaired

           hi  Hearing Impaired

           di  Dialogue

           co  Commentary

           em  Emergency

           vo  Voice Over

           ka  Karaoke

       request_sample_fmt sample_fmt (decoding,audio)
           Set sample format audio decoders should prefer. Default value is "none".

       pkt_timebase rational number
       sub_charenc encoding (decoding,subtitles)
           Set the input subtitles character encoding.

       field_order  field_order (video)
           Set/override the field order of the video.  Possible values:

           progressive
               Progressive video

           tt  Interlaced video, top field coded and displayed first

           bb  Interlaced video, bottom field coded and displayed first

           tb  Interlaced video, top coded first, bottom displayed first

           bt  Interlaced video, bottom coded first, top displayed first

       skip_alpha bool (decoding,video)
           Set to 1 to disable processing alpha (transparency). This works like the gray flag in the flags option which skips
           chroma information instead of alpha. Default is 0.

       codec_whitelist list (input)
           "," separated list of allowed decoders. By default all are allowed.

       dump_separator string (input)
           Separator used to separate the fields printed on the command line about the Stream parameters.  For example, to separate
           the fields with newlines and indentation:

                   ffprobe -dump_separator "
                                             "  -i ~/videos/matrixbench_mpeg2.mpg

       max_pixels integer (decoding/encoding,video)
           Maximum number of pixels per image. This value can be used to avoid out of memory failures due to large images.

       apply_cropping bool (decoding,video)
           Enable cropping if cropping parameters are multiples of the required alignment for the left and top parameters. If the
           alignment is not met the cropping will be partially applied to maintain alignment.  Default is 1 (enabled).  Note: The
           required alignment depends on if "AV_CODEC_FLAG_UNALIGNED" is set and the CPU. "AV_CODEC_FLAG_UNALIGNED" cannot be
           changed from the command line. Also hardware decoders will not apply left/top Cropping.

DECODERS
       Decoders are configured elements in FFmpeg which allow the decoding of multimedia streams.

       When you configure your FFmpeg build, all the supported native decoders are enabled by default. Decoders requiring an
       external library must be enabled manually via the corresponding "--enable-lib" option. You can list all available decoders
       using the configure option "--list-decoders".

       You can disable all the decoders with the configure option "--disable-decoders" and selectively enable / disable single
       decoders with the options "--enable-decoder=DECODER" / "--disable-decoder=DECODER".

       The option "-decoders" of the ff* tools will display the list of enabled decoders.

VIDEO DECODERS
       A description of some of the currently available video decoders follows.

   av1
       AOMedia Video 1 (AV1) decoder.

       Options

       operating_point
           Select an operating point of a scalable AV1 bitstream (0 - 31). Default is 0.

   rawvideo
       Raw video decoder.

       This decoder decodes rawvideo streams.

       Options

       top top_field_first
           Specify the assumed field type of the input video.

           -1  the video is assumed to be progressive (default)

           0   bottom-field-first is assumed

           1   top-field-first is assumed

   libdav1d
       dav1d AV1 decoder.

       libdav1d allows libavcodec to decode the AOMedia Video 1 (AV1) codec.  Requires the presence of the libdav1d headers and
       library during configuration.  You need to explicitly configure the build with "--enable-libdav1d".

       Options

       The following options are supported by the libdav1d wrapper.

       framethreads
           Set amount of frame threads to use during decoding. The default value is 0 (autodetect).  This option is deprecated for
           libdav1d >= 1.0 and will be removed in the future. Use the global option "threads" instead.

       tilethreads
           Set amount of tile threads to use during decoding. The default value is 0 (autodetect).  This option is deprecated for
           libdav1d >= 1.0 and will be removed in the future. Use the global option "threads" instead.

       filmgrain
           Apply film grain to the decoded video if present in the bitstream. Defaults to the internal default of the library.
           This option is deprecated and will be removed in the future. See the global option "export_side_data" to export Film
           Grain parameters instead of applying it.

       oppoint
           Select an operating point of a scalable AV1 bitstream (0 - 31). Defaults to the internal default of the library.

       alllayers
           Output all spatial layers of a scalable AV1 bitstream. The default value is false.

   libdavs2
       AVS2-P2/IEEE1857.4 video decoder wrapper.

       This decoder allows libavcodec to decode AVS2 streams with davs2 library.

   libuavs3d
       AVS3-P2/IEEE1857.10 video decoder.

       libuavs3d allows libavcodec to decode AVS3 streams.  Requires the presence of the libuavs3d headers and library during
       configuration.  You need to explicitly configure the build with "--enable-libuavs3d".

       Options

       The following option is supported by the libuavs3d wrapper.

       frame_threads
           Set amount of frame threads to use during decoding. The default value is 0 (autodetect).

   QSV Decoders
       The family of Intel QuickSync Video decoders (VC1, MPEG-2, H.264, HEVC, JPEG/MJPEG, VP8, VP9, AV1).

       Common Options

       The following options are supported by all qsv decoders.

       async_depth
           Internal parallelization depth, the higher the value the higher the latency.

       gpu_copy
           A GPU-accelerated copy between video and system memory

           default
           on
           off

       HEVC Options

       Extra options for hevc_qsv.

       load_plugin
           A user plugin to load in an internal session

           none
           hevc_sw
           hevc_hw
       load_plugins
           A :-separate list of hexadecimal plugin UIDs to load in an internal session

   v210
       Uncompressed 4:2:2 10-bit decoder.

       Options

       custom_stride
           Set the line size of the v210 data in bytes. The default value is 0 (autodetect). You can use the special -1 value for a
           strideless v210 as seen in BOXX files.

AUDIO DECODERS
       A description of some of the currently available audio decoders follows.

   ac3
       AC-3 audio decoder.

       This decoder implements part of ATSC A/52:2010 and ETSI TS 102 366, as well as the undocumented RealAudio 3 (a.k.a. dnet).

       AC-3 Decoder Options

       -drc_scale value
           Dynamic Range Scale Factor. The factor to apply to dynamic range values from the AC-3 stream. This factor is applied
           exponentially. The default value is 1.  There are 3 notable scale factor ranges:

           drc_scale == 0
               DRC disabled. Produces full range audio.

           0 < drc_scale <= 1
               DRC enabled.  Applies a fraction of the stream DRC value.  Audio reproduction is between full range and full
               compression.

           drc_scale > 1
               DRC enabled. Applies drc_scale asymmetrically.  Loud sounds are fully compressed.  Soft sounds are enhanced.

   flac
       FLAC audio decoder.

       This decoder aims to implement the complete FLAC specification from Xiph.

       FLAC Decoder options

       -use_buggy_lpc
           The lavc FLAC encoder used to produce buggy streams with high lpc values (like the default value). This option makes it
           possible to decode such streams correctly by using lavc's old buggy lpc logic for decoding.

   ffwavesynth
       Internal wave synthesizer.

       This decoder generates wave patterns according to predefined sequences. Its use is purely internal and the format of the
       data it accepts is not publicly documented.

   libcelt
       libcelt decoder wrapper.

       libcelt allows libavcodec to decode the Xiph CELT ultra-low delay audio codec.  Requires the presence of the libcelt headers
       and library during configuration.  You need to explicitly configure the build with "--enable-libcelt".

   libgsm
       libgsm decoder wrapper.

       libgsm allows libavcodec to decode the GSM full rate audio codec. Requires the presence of the libgsm headers and library
       during configuration. You need to explicitly configure the build with "--enable-libgsm".

       This decoder supports both the ordinary GSM and the Microsoft variant.

   libilbc
       libilbc decoder wrapper.

       libilbc allows libavcodec to decode the Internet Low Bitrate Codec (iLBC) audio codec. Requires the presence of the libilbc
       headers and library during configuration. You need to explicitly configure the build with "--enable-libilbc".

       Options

       The following option is supported by the libilbc wrapper.

       enhance
           Enable the enhancement of the decoded audio when set to 1. The default value is 0 (disabled).

   libopencore-amrnb
       libopencore-amrnb decoder wrapper.

       libopencore-amrnb allows libavcodec to decode the Adaptive Multi-Rate Narrowband audio codec. Using it requires the presence
       of the libopencore-amrnb headers and library during configuration. You need to explicitly configure the build with
       "--enable-libopencore-amrnb".

       An FFmpeg native decoder for AMR-NB exists, so users can decode AMR-NB without this library.

   libopencore-amrwb
       libopencore-amrwb decoder wrapper.

       libopencore-amrwb allows libavcodec to decode the Adaptive Multi-Rate Wideband audio codec. Using it requires the presence
       of the libopencore-amrwb headers and library during configuration. You need to explicitly configure the build with
       "--enable-libopencore-amrwb".

       An FFmpeg native decoder for AMR-WB exists, so users can decode AMR-WB without this library.

   libopus
       libopus decoder wrapper.

       libopus allows libavcodec to decode the Opus Interactive Audio Codec.  Requires the presence of the libopus headers and
       library during configuration. You need to explicitly configure the build with "--enable-libopus".

       An FFmpeg native decoder for Opus exists, so users can decode Opus without this library.

SUBTITLES DECODERS
   libaribb24
       ARIB STD-B24 caption decoder.

       Implements profiles A and C of the ARIB STD-B24 standard.

       libaribb24 Decoder Options

       -aribb24-base-path path
           Sets the base path for the libaribb24 library. This is utilized for reading of configuration files (for custom unicode
           conversions), and for dumping of non-text symbols as images under that location.

           Unset by default.

       -aribb24-skip-ruby-text boolean
           Tells the decoder wrapper to skip text blocks that contain half-height ruby text.

           Enabled by default.

   dvbsub
       Options

       compute_clut
           -2  Compute clut once if no matching CLUT is in the stream.

           -1  Compute clut if no matching CLUT is in the stream.

           0   Never compute CLUT

           1   Always compute CLUT and override the one provided in the stream.

       dvb_substream
           Selects the dvb substream, or all substreams if -1 which is default.

   dvdsub
       This codec decodes the bitmap subtitles used in DVDs; the same subtitles can also be found in VobSub file pairs and in some
       Matroska files.

       Options

       palette
           Specify the global palette used by the bitmaps. When stored in VobSub, the palette is normally specified in the index
           file; in Matroska, the palette is stored in the codec extra-data in the same format as in VobSub. In DVDs, the palette
           is stored in the IFO file, and therefore not available when reading from dumped VOB files.

           The format for this option is a string containing 16 24-bits hexadecimal numbers (without 0x prefix) separated by
           commas, for example "0d00ee, ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1, 7b2a0e, 0d950c,
           0f007b, cf0dec, cfa80c, 7c127b".

       ifo_palette
           Specify the IFO file from which the global palette is obtained.  (experimental)

       forced_subs_only
           Only decode subtitle entries marked as forced. Some titles have forced and non-forced subtitles in the same track.
           Setting this flag to 1 will only keep the forced subtitles. Default value is 0.

   libzvbi-teletext
       Libzvbi allows libavcodec to decode DVB teletext pages and DVB teletext subtitles. Requires the presence of the libzvbi
       headers and library during configuration. You need to explicitly configure the build with "--enable-libzvbi".

       Options

       txt_page
           List of teletext page numbers to decode. Pages that do not match the specified list are dropped. You may use the special
           "*" string to match all pages, or "subtitle" to match all subtitle pages.  Default value is *.

       txt_default_region
           Set default character set used for decoding, a value between 0 and 87 (see ETS 300 706, Section 15, Table 32). Default
           value is -1, which does not override the libzvbi default. This option is needed for some legacy level 1.0 transmissions
           which cannot signal the proper charset.

       txt_chop_top
           Discards the top teletext line. Default value is 1.

       txt_format
           Specifies the format of the decoded subtitles.

           bitmap
               The default format, you should use this for teletext pages, because certain graphics and colors cannot be expressed
               in simple text or even ASS.

           text
               Simple text based output without formatting.

           ass Formatted ASS output, subtitle pages and teletext pages are returned in different styles, subtitle pages are
               stripped down to text, but an effort is made to keep the text alignment and the formatting.

       txt_left
           X offset of generated bitmaps, default is 0.

       txt_top
           Y offset of generated bitmaps, default is 0.

       txt_chop_spaces
           Chops leading and trailing spaces and removes empty lines from the generated text. This option is useful for teletext
           based subtitles where empty spaces may be present at the start or at the end of the lines or empty lines may be present
           between the subtitle lines because of double-sized teletext characters.  Default value is 1.

       txt_duration
           Sets the display duration of the decoded teletext pages or subtitles in milliseconds. Default value is -1 which means
           infinity or until the next subtitle event comes.

       txt_transparent
           Force transparent background of the generated teletext bitmaps. Default value is 0 which means an opaque background.

       txt_opacity
           Sets the opacity (0-255) of the teletext background. If txt_transparent is not set, it only affects characters between a
           start box and an end box, typically subtitles. Default value is 0 if txt_transparent is set, 255 otherwise.

BITSTREAM FILTERS
       When you configure your FFmpeg build, all the supported bitstream filters are enabled by default. You can list all available
       ones using the configure option "--list-bsfs".

       You can disable all the bitstream filters using the configure option "--disable-bsfs", and selectively enable any bitstream
       filter using the option "--enable-bsf=BSF", or you can disable a particular bitstream filter using the option
       "--disable-bsf=BSF".

       The option "-bsfs" of the ff* tools will display the list of all the supported bitstream filters included in your build.

       The ff* tools have a -bsf option applied per stream, taking a comma-separated list of filters, whose parameters follow the
       filter name after a '='.

               ffmpeg -i INPUT -c:v copy -bsf:v filter1[=opt1=str1:opt2=str2][,filter2] OUTPUT

       Below is a description of the currently available bitstream filters, with their parameters, if any.

   aac_adtstoasc
       Convert MPEG-2/4 AAC ADTS to an MPEG-4 Audio Specific Configuration bitstream.

       This filter creates an MPEG-4 AudioSpecificConfig from an MPEG-2/4 ADTS header and removes the ADTS header.

       This filter is required for example when copying an AAC stream from a raw ADTS AAC or an MPEG-TS container to MP4A-LATM, to
       an FLV file, or to MOV/MP4 files and related formats such as 3GP or M4A. Please note that it is auto-inserted for MP4A-LATM
       and MOV/MP4 and related formats.

   av1_metadata
       Modify metadata embedded in an AV1 stream.

       td  Insert or remove temporal delimiter OBUs in all temporal units of the stream.

           insert
               Insert a TD at the beginning of every TU which does not already have one.

           remove
               Remove the TD from the beginning of every TU which has one.

       color_primaries
       transfer_characteristics
       matrix_coefficients
           Set the color description fields in the stream (see AV1 section 6.4.2).

       color_range
           Set the color range in the stream (see AV1 section 6.4.2; note that this cannot be set for streams using BT.709
           primaries, sRGB transfer characteristic and identity (RGB) matrix coefficients).

           tv  Limited range.

           pc  Full range.

       chroma_sample_position
           Set the chroma sample location in the stream (see AV1 section 6.4.2).  This can only be set for 4:2:0 streams.

           vertical
               Left position (matching the default in MPEG-2 and H.264).

           colocated
               Top-left position.

       tick_rate
           Set the tick rate (time_scale / num_units_in_display_tick) in the timing info in the sequence header.

       num_ticks_per_picture
           Set the number of ticks in each picture, to indicate that the stream has a fixed framerate.  Ignored if tick_rate is not
           also set.

       delete_padding
           Deletes Padding OBUs.

   chomp
       Remove zero padding at the end of a packet.

   dca_core
       Extract the core from a DCA/DTS stream, dropping extensions such as DTS-HD.

   dump_extra
       Add extradata to the beginning of the filtered packets except when said packets already exactly begin with the extradata
       that is intended to be added.

       freq
           The additional argument specifies which packets should be filtered.  It accepts the values:

           k
           keyframe
               add extradata to all key packets

           e
           all add extradata to all packets

       If not specified it is assumed k.

       For example the following ffmpeg command forces a global header (thus disabling individual packet headers) in the H.264
       packets generated by the "libx264" encoder, but corrects them by adding the header stored in extradata to the key packets:

               ffmpeg -i INPUT -map 0 -flags:v +global_header -c:v libx264 -bsf:v dump_extra out.ts

   dv_error_marker
       Blocks in DV which are marked as damaged are replaced by blocks of the specified color.

       color
           The color to replace damaged blocks by

       sta A 16 bit mask which specifies which of the 16 possible error status values are to be replaced by colored blocks. 0xFFFE
           is the default which replaces all non 0 error status values.

           ok  No error, no concealment

           err Error, No concealment

           res Reserved

           notok
               Error or concealment

           notres
               Not reserved

           Aa, Ba, Ca, Ab, Bb, Cb, A, B, C, a, b, erri, erru
               The specific error status code

           see page 44-46 or section 5.5 of
           <http://web.archive.org/web/20060927044735/http://www.smpte.org/smpte_store/standards/pdf/s314m.pdf>

   eac3_core
       Extract the core from a E-AC-3 stream, dropping extra channels.

   extract_extradata
       Extract the in-band extradata.

       Certain codecs allow the long-term headers (e.g. MPEG-2 sequence headers, or H.264/HEVC (VPS/)SPS/PPS) to be transmitted
       either "in-band" (i.e. as a part of the bitstream containing the coded frames) or "out of band" (e.g. on the container
       level). This latter form is called "extradata" in FFmpeg terminology.

       This bitstream filter detects the in-band headers and makes them available as extradata.

       remove
           When this option is enabled, the long-term headers are removed from the bitstream after extraction.

   filter_units
       Remove units with types in or not in a given set from the stream.

       pass_types
           List of unit types or ranges of unit types to pass through while removing all others.  This is specified as a
           '|'-separated list of unit type values or ranges of values with '-'.

       remove_types
           Identical to pass_types, except the units in the given set removed and all others passed through.

       Extradata is unchanged by this transformation, but note that if the stream contains inline parameter sets then the output
       may be unusable if they are removed.

       For example, to remove all non-VCL NAL units from an H.264 stream:

               ffmpeg -i INPUT -c:v copy -bsf:v 'filter_units=pass_types=1-5' OUTPUT

       To remove all AUDs, SEI and filler from an H.265 stream:

               ffmpeg -i INPUT -c:v copy -bsf:v 'filter_units=remove_types=35|38-40' OUTPUT

   hapqa_extract
       Extract Rgb or Alpha part of an HAPQA file, without recompression, in order to create an HAPQ or an HAPAlphaOnly file.

       texture
           Specifies the texture to keep.

           color
           alpha

       Convert HAPQA to HAPQ

               ffmpeg -i hapqa_inputfile.mov -c copy -bsf:v hapqa_extract=texture=color -tag:v HapY -metadata:s:v:0 encoder="HAPQ" hapq_file.mov

       Convert HAPQA to HAPAlphaOnly

               ffmpeg -i hapqa_inputfile.mov -c copy -bsf:v hapqa_extract=texture=alpha -tag:v HapA -metadata:s:v:0 encoder="HAPAlpha Only" hapalphaonly_file.mov

   h264_metadata
       Modify metadata embedded in an H.264 stream.

       aud Insert or remove AUD NAL units in all access units of the stream.

           pass
           insert
           remove

           Default is pass.

       sample_aspect_ratio
           Set the sample aspect ratio of the stream in the VUI parameters.  See H.264 table E-1.

       overscan_appropriate_flag
           Set whether the stream is suitable for display using overscan or not (see H.264 section E.2.1).

       video_format
       video_full_range_flag
           Set the video format in the stream (see H.264 section E.2.1 and table E-2).

       colour_primaries
       transfer_characteristics
       matrix_coefficients
           Set the colour description in the stream (see H.264 section E.2.1 and tables E-3, E-4 and E-5).

       chroma_sample_loc_type
           Set the chroma sample location in the stream (see H.264 section E.2.1 and figure E-1).

       tick_rate
           Set the tick rate (time_scale / num_units_in_tick) in the VUI parameters.  This is the smallest time unit representable
           in the stream, and in many cases represents the field rate of the stream (double the frame rate).

       fixed_frame_rate_flag
           Set whether the stream has fixed framerate - typically this indicates that the framerate is exactly half the tick rate,
           but the exact meaning is dependent on interlacing and the picture structure (see H.264 section E.2.1 and table E-6).

       zero_new_constraint_set_flags
           Zero constraint_set4_flag and constraint_set5_flag in the SPS. These bits were reserved in a previous version of the
           H.264 spec, and thus some hardware decoders require these to be zero. The result of zeroing this is still a valid
           bitstream.

       crop_left
       crop_right
       crop_top
       crop_bottom
           Set the frame cropping offsets in the SPS.  These values will replace the current ones if the stream is already cropped.

           These fields are set in pixels.  Note that some sizes may not be representable if the chroma is subsampled or the stream
           is interlaced (see H.264 section 7.4.2.1.1).

       sei_user_data
           Insert a string as SEI unregistered user data.  The argument must be of the form UUID+string, where the UUID is as hex
           digits possibly separated by hyphens, and the string can be anything.

           For example, 086f3693-b7b3-4f2c-9653-21492feee5b8+hello will insert the string ``hello'' associated with the given UUID.

       delete_filler
           Deletes both filler NAL units and filler SEI messages.

       display_orientation
           Insert, extract or remove Display orientation SEI messages.  See H.264 section D.1.27 and D.2.27 for syntax and
           semantics.

           pass
           insert
           remove
           extract

           Default is pass.

           Insert mode works in conjunction with "rotate" and "flip" options.  Any pre-existing Display orientation messages will
           be removed in insert or remove mode.  Extract mode attaches the display matrix to the packet as side data.

       rotate
           Set rotation in display orientation SEI (anticlockwise angle in degrees).  Range is -360 to +360. Default is NaN.

       flip
           Set flip in display orientation SEI.

           horizontal
           vertical

           Default is unset.

       level
           Set the level in the SPS.  Refer to H.264 section A.3 and tables A-1 to A-5.

           The argument must be the name of a level (for example, 4.2), a level_idc value (for example, 42), or the special name
           auto indicating that the filter should attempt to guess the level from the input stream properties.

   h264_mp4toannexb
       Convert an H.264 bitstream from length prefixed mode to start code prefixed mode (as defined in the Annex B of the ITU-T
       H.264 specification).

       This is required by some streaming formats, typically the MPEG-2 transport stream format (muxer "mpegts").

       For example to remux an MP4 file containing an H.264 stream to mpegts format with ffmpeg, you can use the command:

               ffmpeg -i INPUT.mp4 -codec copy -bsf:v h264_mp4toannexb OUTPUT.ts

       Please note that this filter is auto-inserted for MPEG-TS (muxer "mpegts") and raw H.264 (muxer "h264") output formats.

   h264_redundant_pps
       This applies a specific fixup to some Blu-ray streams which contain redundant PPSs modifying irrelevant parameters of the
       stream which confuse other transformations which require correct extradata.

       A new single global PPS is created, and all of the redundant PPSs within the stream are removed.

   hevc_metadata
       Modify metadata embedded in an HEVC stream.

       aud Insert or remove AUD NAL units in all access units of the stream.

           insert
           remove
       sample_aspect_ratio
           Set the sample aspect ratio in the stream in the VUI parameters.

       video_format
       video_full_range_flag
           Set the video format in the stream (see H.265 section E.3.1 and table E.2).

       colour_primaries
       transfer_characteristics
       matrix_coefficients
           Set the colour description in the stream (see H.265 section E.3.1 and tables E.3, E.4 and E.5).

       chroma_sample_loc_type
           Set the chroma sample location in the stream (see H.265 section E.3.1 and figure E.1).

       tick_rate
           Set the tick rate in the VPS and VUI parameters (time_scale / num_units_in_tick). Combined with num_ticks_poc_diff_one,
           this can set a constant framerate in the stream.  Note that it is likely to be overridden by container parameters when
           the stream is in a container.

       num_ticks_poc_diff_one
           Set poc_proportional_to_timing_flag in VPS and VUI and use this value to set num_ticks_poc_diff_one_minus1 (see H.265
           sections 7.4.3.1 and E.3.1).  Ignored if tick_rate is not also set.

       crop_left
       crop_right
       crop_top
       crop_bottom
           Set the conformance window cropping offsets in the SPS.  These values will replace the current ones if the stream is
           already cropped.

           These fields are set in pixels.  Note that some sizes may not be representable if the chroma is subsampled (H.265
           section 7.4.3.2.1).

       level
           Set the level in the VPS and SPS.  See H.265 section A.4 and tables A.6 and A.7.

           The argument must be the name of a level (for example, 5.1), a general_level_idc value (for example, 153 for level 5.1),
           or the special name auto indicating that the filter should attempt to guess the level from the input stream properties.

   hevc_mp4toannexb
       Convert an HEVC/H.265 bitstream from length prefixed mode to start code prefixed mode (as defined in the Annex B of the ITU-
       T H.265 specification).

       This is required by some streaming formats, typically the MPEG-2 transport stream format (muxer "mpegts").

       For example to remux an MP4 file containing an HEVC stream to mpegts format with ffmpeg, you can use the command:

               ffmpeg -i INPUT.mp4 -codec copy -bsf:v hevc_mp4toannexb OUTPUT.ts

       Please note that this filter is auto-inserted for MPEG-TS (muxer "mpegts") and raw HEVC/H.265 (muxer "h265" or "hevc")
       output formats.

   imxdump
       Modifies the bitstream to fit in MOV and to be usable by the Final Cut Pro decoder. This filter only applies to the
       mpeg2video codec, and is likely not needed for Final Cut Pro 7 and newer with the appropriate -tag:v.

       For example, to remux 30 MB/sec NTSC IMX to MOV:

               ffmpeg -i input.mxf -c copy -bsf:v imxdump -tag:v mx3n output.mov

   mjpeg2jpeg
       Convert MJPEG/AVI1 packets to full JPEG/JFIF packets.

       MJPEG is a video codec wherein each video frame is essentially a JPEG image. The individual frames can be extracted without
       loss, e.g. by

               ffmpeg -i ../some_mjpeg.avi -c:v copy frames_%d.jpg

       Unfortunately, these chunks are incomplete JPEG images, because they lack the DHT segment required for decoding. Quoting
       from <http://www.digitalpreservation.gov/formats/fdd/fdd000063.shtml>:

       Avery Lee, writing in the rec.video.desktop newsgroup in 2001, commented that "MJPEG, or at least the MJPEG in AVIs having
       the MJPG fourcc, is restricted JPEG with a fixed -- and *omitted* -- Huffman table. The JPEG must be YCbCr colorspace, it
       must be 4:2:2, and it must use basic Huffman encoding, not arithmetic or progressive. . . . You can indeed extract the MJPEG
       frames and decode them with a regular JPEG decoder, but you have to prepend the DHT segment to them, or else the decoder
       won't have any idea how to decompress the data. The exact table necessary is given in the OpenDML spec."

       This bitstream filter patches the header of frames extracted from an MJPEG stream (carrying the AVI1 header ID and lacking a
       DHT segment) to produce fully qualified JPEG images.

               ffmpeg -i mjpeg-movie.avi -c:v copy -bsf:v mjpeg2jpeg frame_%d.jpg
               exiftran -i -9 frame*.jpg
               ffmpeg -i frame_%d.jpg -c:v copy rotated.avi

   mjpegadump
       Add an MJPEG A header to the bitstream, to enable decoding by Quicktime.

   mov2textsub
       Extract a representable text file from MOV subtitles, stripping the metadata header from each subtitle packet.

       See also the text2movsub filter.

   mp3decomp
       Decompress non-standard compressed MP3 audio headers.

   mpeg2_metadata
       Modify metadata embedded in an MPEG-2 stream.

       display_aspect_ratio
           Set the display aspect ratio in the stream.

           The following fixed values are supported:

           4/3
           16/9
           221/100

           Any other value will result in square pixels being signalled instead (see H.262 section 6.3.3 and table 6-3).

       frame_rate
           Set the frame rate in the stream.  This is constructed from a table of known values combined with a small multiplier and
           divisor - if the supplied value is not exactly representable, the nearest representable value will be used instead (see
           H.262 section 6.3.3 and table 6-4).

       video_format
           Set the video format in the stream (see H.262 section 6.3.6 and table 6-6).

       colour_primaries
       transfer_characteristics
       matrix_coefficients
           Set the colour description in the stream (see H.262 section 6.3.6 and tables 6-7, 6-8 and 6-9).

   mpeg4_unpack_bframes
       Unpack DivX-style packed B-frames.

       DivX-style packed B-frames are not valid MPEG-4 and were only a workaround for the broken Video for Windows subsystem.  They
       use more space, can cause minor AV sync issues, require more CPU power to decode (unless the player has some decoded picture
       queue to compensate the 2,0,2,0 frame per packet style) and cause trouble if copied into a standard container like mp4 or
       mpeg-ps/ts, because MPEG-4 decoders may not be able to decode them, since they are not valid MPEG-4.

       For example to fix an AVI file containing an MPEG-4 stream with DivX-style packed B-frames using ffmpeg, you can use the
       command:

               ffmpeg -i INPUT.avi -codec copy -bsf:v mpeg4_unpack_bframes OUTPUT.avi

   noise
       Damages the contents of packets or simply drops them without damaging the container. Can be used for fuzzing or testing
       error resilience/concealment.

       Parameters:

       amount
           Accepts an expression whose evaluation per-packet determines how often bytes in that packet will be modified. A value
           below 0 will result in a variable frequency.  Default is 0 which results in no modification. However, if neither amount
           nor drop is specified, amount will be set to -1. See below for accepted variables.

       drop
           Accepts an expression evaluated per-packet whose value determines whether that packet is dropped.  Evaluation to a
           positive value results in the packet being dropped. Evaluation to a negative value results in a variable chance of it
           being dropped, roughly inverse in proportion to the magnitude of the value. Default is 0 which results in no drops. See
           below for accepted variables.

       dropamount
           Accepts a non-negative integer, which assigns a variable chance of it being dropped, roughly inverse in proportion to
           the value. Default is 0 which results in no drops. This option is kept for backwards compatibility and is equivalent to
           setting drop to a negative value with the same magnitude i.e. "dropamount=4" is the same as "drop=-4". Ignored if drop
           is also specified.

       Both "amount" and "drop" accept expressions containing the following variables:

       n   The index of the packet, starting from zero.

       tb  The timebase for packet timestamps.

       pts Packet presentation timestamp.

       dts Packet decoding timestamp.

       nopts
           Constant representing AV_NOPTS_VALUE.

       startpts
           First non-AV_NOPTS_VALUE PTS seen in the stream.

       startdts
           First non-AV_NOPTS_VALUE DTS seen in the stream.

       duration
       d   Packet duration, in timebase units.

       pos Packet position in input; may be -1 when unknown or not set.

       size
           Packet size, in bytes.

       key Whether packet is marked as a keyframe.

       state
           A pseudo random integer, primarily derived from the content of packet payload.

       Examples

       Apply modification to every byte but don't drop any packets.

               ffmpeg -i INPUT -c copy -bsf noise=1 output.mkv

       Drop every video packet not marked as a keyframe after timestamp 30s but do not modify any of the remaining packets.

               ffmpeg -i INPUT -c copy -bsf:v noise=drop='gt(t\,30)*not(key)' output.mkv

       Drop one second of audio every 10 seconds and add some random noise to the rest.

               ffmpeg -i INPUT -c copy -bsf:a noise=amount=-1:drop='between(mod(t\,10)\,9\,10)' output.mkv

   null
       This bitstream filter passes the packets through unchanged.

   pcm_rechunk
       Repacketize PCM audio to a fixed number of samples per packet or a fixed packet rate per second. This is similar to the
       asetnsamples audio filter but works on audio packets instead of audio frames.

       nb_out_samples, n
           Set the number of samples per each output audio packet. The number is intended as the number of samples per each
           channel. Default value is 1024.

       pad, p
           If set to 1, the filter will pad the last audio packet with silence, so that it will contain the same number of samples
           (or roughly the same number of samples, see frame_rate) as the previous ones. Default value is 1.

       frame_rate, r
           This option makes the filter output a fixed number of packets per second instead of a fixed number of samples per
           packet. If the audio sample rate is not divisible by the frame rate then the number of samples will not be constant but
           will vary slightly so that each packet will start as close to the frame boundary as possible. Using this option has
           precedence over nb_out_samples.

       You can generate the well known 1602-1601-1602-1601-1602 pattern of 48kHz audio for NTSC frame rate using the frame_rate
       option.

               ffmpeg -f lavfi -i sine=r=48000:d=1 -c pcm_s16le -bsf pcm_rechunk=r=30000/1001 -f framecrc -

   pgs_frame_merge
       Merge a sequence of PGS Subtitle segments ending with an "end of display set" segment into a single packet.

       This is required by some containers that support PGS subtitles (muxer "matroska").

   prores_metadata
       Modify color property metadata embedded in prores stream.

       color_primaries
           Set the color primaries.  Available values are:

           auto
               Keep the same color primaries property (default).

           unknown
           bt709
           bt470bg
               BT601 625

           smpte170m
               BT601 525

           bt2020
           smpte431
               DCI P3

           smpte432
               P3 D65

       transfer_characteristics
           Set the color transfer.  Available values are:

           auto
               Keep the same transfer characteristics property (default).

           unknown
           bt709
               BT 601, BT 709, BT 2020

           smpte2084
               SMPTE ST 2084

           arib-std-b67
               ARIB STD-B67

       matrix_coefficients
           Set the matrix coefficient.  Available values are:

           auto
               Keep the same colorspace property (default).

           unknown
           bt709
           smpte170m
               BT 601

           bt2020nc

       Set Rec709 colorspace for each frame of the file

               ffmpeg -i INPUT -c copy -bsf:v prores_metadata=color_primaries=bt709:color_trc=bt709:colorspace=bt709 output.mov

       Set Hybrid Log-Gamma parameters for each frame of the file

               ffmpeg -i INPUT -c copy -bsf:v prores_metadata=color_primaries=bt2020:color_trc=arib-std-b67:colorspace=bt2020nc output.mov

   remove_extra
       Remove extradata from packets.

       It accepts the following parameter:

       freq
           Set which frame types to remove extradata from.

           k   Remove extradata from non-keyframes only.

           keyframe
               Remove extradata from keyframes only.

           e, all
               Remove extradata from all frames.

   setts
       Set PTS and DTS in packets.

       It accepts the following parameters:

       ts
       pts
       dts Set expressions for PTS, DTS or both.

       duration
           Set expression for duration.

       time_base
           Set output time base.

       The expressions are evaluated through the eval API and can contain the following constants:

       N   The count of the input packet. Starting from 0.

       TS  The demux timestamp in input in case of "ts" or "dts" option or presentation timestamp in case of "pts" option.

       POS The original position in the file of the packet, or undefined if undefined for the current packet

       DTS The demux timestamp in input.

       PTS The presentation timestamp in input.

       DURATION
           The duration in input.

       STARTDTS
           The DTS of the first packet.

       STARTPTS
           The PTS of the first packet.

       PREV_INDTS
           The previous input DTS.

       PREV_INPTS
           The previous input PTS.

       PREV_INDURATION
           The previous input duration.

       PREV_OUTDTS
           The previous output DTS.

       PREV_OUTPTS
           The previous output PTS.

       PREV_OUTDURATION
           The previous output duration.

       NEXT_DTS
           The next input DTS.

       NEXT_PTS
           The next input PTS.

       NEXT_DURATION
           The next input duration.

       TB  The timebase of stream packet belongs.

       TB_OUT
           The output timebase.

       SR  The sample rate of stream packet belongs.

       NOPTS
           The AV_NOPTS_VALUE constant.

   text2movsub
       Convert text subtitles to MOV subtitles (as used by the "mov_text" codec) with metadata headers.

       See also the mov2textsub filter.

   trace_headers
       Log trace output containing all syntax elements in the coded stream headers (everything above the level of individual coded
       blocks).  This can be useful for debugging low-level stream issues.

       Supports AV1, H.264, H.265, (M)JPEG, MPEG-2 and VP9, but depending on the build only a subset of these may be available.

   truehd_core
       Extract the core from a TrueHD stream, dropping ATMOS data.

   vp9_metadata
       Modify metadata embedded in a VP9 stream.

       color_space
           Set the color space value in the frame header.  Note that any frame set to RGB will be implicitly set to PC range and
           that RGB is incompatible with profiles 0 and 2.

           unknown
           bt601
           bt709
           smpte170
           smpte240
           bt2020
           rgb
       color_range
           Set the color range value in the frame header.  Note that any value imposed by the color space will take precedence over
           this value.

           tv
           pc

   vp9_superframe
       Merge VP9 invisible (alt-ref) frames back into VP9 superframes. This fixes merging of split/segmented VP9 streams where the
       alt-ref frame was split from its visible counterpart.

   vp9_superframe_split
       Split VP9 superframes into single frames.

   vp9_raw_reorder
       Given a VP9 stream with correct timestamps but possibly out of order, insert additional show-existing-frame packets to
       correct the ordering.

FORMAT OPTIONS
       The libavformat library provides some generic global options, which can be set on all the muxers and demuxers. In addition
       each muxer or demuxer may support so-called private options, which are specific for that component.

       Options may be set by specifying -option value in the FFmpeg tools, or by setting the value explicitly in the
       "AVFormatContext" options or using the libavutil/opt.h API for programmatic use.

       The list of supported options follows:

       avioflags flags (input/output)
           Possible values:

           direct
               Reduce buffering.

       probesize integer (input)
           Set probing size in bytes, i.e. the size of the data to analyze to get stream information. A higher value will enable
           detecting more information in case it is dispersed into the stream, but will increase latency. Must be an integer not
           lesser than 32. It is 5000000 by default.

       max_probe_packets integer (input)
           Set the maximum number of buffered packets when probing a codec.  Default is 2500 packets.

       packetsize integer (output)
           Set packet size.

       fflags flags
           Set format flags. Some are implemented for a limited number of formats.

           Possible values for input files:

           discardcorrupt
               Discard corrupted packets.

           fastseek
               Enable fast, but inaccurate seeks for some formats.

           genpts
               Generate missing PTS if DTS is present.

           igndts
               Ignore DTS if PTS is set. Inert when nofillin is set.

           ignidx
               Ignore index.

           nobuffer
               Reduce the latency introduced by buffering during initial input streams analysis.

           nofillin
               Do not fill in missing values in packet fields that can be exactly calculated.

           noparse
               Disable AVParsers, this needs "+nofillin" too.

           sortdts
               Try to interleave output packets by DTS. At present, available only for AVIs with an index.

           Possible values for output files:

           autobsf
               Automatically apply bitstream filters as required by the output format. Enabled by default.

           bitexact
               Only write platform-, build- and time-independent data.  This ensures that file and data checksums are reproducible
               and match between platforms. Its primary use is for regression testing.

           flush_packets
               Write out packets immediately.

           shortest
               Stop muxing at the end of the shortest stream.  It may be needed to increase max_interleave_delta to avoid flushing
               the longer streams before EOF.

       seek2any integer (input)
           Allow seeking to non-keyframes on demuxer level when supported if set to 1.  Default is 0.

       analyzeduration integer (input)
           Specify how many microseconds are analyzed to probe the input. A higher value will enable detecting more accurate
           information, but will increase latency. It defaults to 5,000,000 microseconds = 5 seconds.

       cryptokey hexadecimal string (input)
           Set decryption key.

       indexmem integer (input)
           Set max memory used for timestamp index (per stream).

       rtbufsize integer (input)
           Set max memory used for buffering real-time frames.

       fdebug flags (input/output)
           Print specific debug info.

           Possible values:

           ts
       max_delay integer (input/output)
           Set maximum muxing or demuxing delay in microseconds.

       fpsprobesize integer (input)
           Set number of frames used to probe fps.

       audio_preload integer (output)
           Set microseconds by which audio packets should be interleaved earlier.

       chunk_duration integer (output)
           Set microseconds for each chunk.

       chunk_size integer (output)
           Set size in bytes for each chunk.

       err_detect, f_err_detect flags (input)
           Set error detection flags. "f_err_detect" is deprecated and should be used only via the ffmpeg tool.

           Possible values:

           crccheck
               Verify embedded CRCs.

           bitstream
               Detect bitstream specification deviations.

           buffer
               Detect improper bitstream length.

           explode
               Abort decoding on minor error detection.

           careful
               Consider things that violate the spec and have not been seen in the wild as errors.

           compliant
               Consider all spec non compliancies as errors.

           aggressive
               Consider things that a sane encoder should not do as an error.

       max_interleave_delta integer (output)
           Set maximum buffering duration for interleaving. The duration is expressed in microseconds, and defaults to 10000000 (10
           seconds).

           To ensure all the streams are interleaved correctly, libavformat will wait until it has at least one packet for each
           stream before actually writing any packets to the output file. When some streams are "sparse" (i.e. there are large gaps
           between successive packets), this can result in excessive buffering.

           This field specifies the maximum difference between the timestamps of the first and the last packet in the muxing queue,
           above which libavformat will output a packet regardless of whether it has queued a packet for all the streams.

           If set to 0, libavformat will continue buffering packets until it has a packet for each stream, regardless of the
           maximum timestamp difference between the buffered packets.

       use_wallclock_as_timestamps integer (input)
           Use wallclock as timestamps if set to 1. Default is 0.

       avoid_negative_ts integer (output)
           Possible values:

           make_non_negative
               Shift timestamps to make them non-negative.  Also note that this affects only leading negative timestamps, and not
               non-monotonic negative timestamps.

           make_zero
               Shift timestamps so that the first timestamp is 0.

           auto (default)
               Enables shifting when required by the target format.

           disabled
               Disables shifting of timestamp.

           When shifting is enabled, all output timestamps are shifted by the same amount. Audio, video, and subtitles desynching
           and relative timestamp differences are preserved compared to how they would have been without shifting.

       skip_initial_bytes integer (input)
           Set number of bytes to skip before reading header and frames if set to 1.  Default is 0.

       correct_ts_overflow integer (input)
           Correct single timestamp overflows if set to 1. Default is 1.

       flush_packets integer (output)
           Flush the underlying I/O stream after each packet. Default is -1 (auto), which means that the underlying protocol will
           decide, 1 enables it, and has the effect of reducing the latency, 0 disables it and may increase IO throughput in some
           cases.

       output_ts_offset offset (output)
           Set the output time offset.

           offset must be a time duration specification, see the Time duration section in the ffmpeg-utils(1) manual.

           The offset is added by the muxer to the output timestamps.

           Specifying a positive offset means that the corresponding streams are delayed bt the time duration specified in offset.
           Default value is 0 (meaning that no offset is applied).

       format_whitelist list (input)
           "," separated list of allowed demuxers. By default all are allowed.

       dump_separator string (input)
           Separator used to separate the fields printed on the command line about the Stream parameters.  For example, to separate
           the fields with newlines and indentation:

                   ffprobe -dump_separator "
                                             "  -i ~/videos/matrixbench_mpeg2.mpg

       max_streams integer (input)
           Specifies the maximum number of streams. This can be used to reject files that would require too many resources due to a
           large number of streams.

       skip_estimate_duration_from_pts bool (input)
           Skip estimation of input duration when calculated using PTS.  At present, applicable for MPEG-PS and MPEG-TS.

       strict, f_strict integer (input/output)
           Specify how strictly to follow the standards. "f_strict" is deprecated and should be used only via the ffmpeg tool.

           Possible values:

           very
               strictly conform to an older more strict version of the spec or reference software

           strict
               strictly conform to all the things in the spec no matter what consequences

           normal
           unofficial
               allow unofficial extensions

           experimental
               allow non standardized experimental things, experimental (unfinished/work in progress/not well tested) decoders and
               encoders.  Note: experimental decoders can pose a security risk, do not use this for decoding untrusted input.

   Format stream specifiers
       Format stream specifiers allow selection of one or more streams that match specific properties.

       The exact semantics of stream specifiers is defined by the "avformat_match_stream_specifier()" function declared in the
       libavformat/avformat.h header and documented in the Stream specifiers section in the ffmpeg(1) manual.

DEMUXERS
       Demuxers are configured elements in FFmpeg that can read the multimedia streams from a particular type of file.

       When you configure your FFmpeg build, all the supported demuxers are enabled by default. You can list all available ones
       using the configure option "--list-demuxers".

       You can disable all the demuxers using the configure option "--disable-demuxers", and selectively enable a single demuxer
       with the option "--enable-demuxer=DEMUXER", or disable it with the option "--disable-demuxer=DEMUXER".

       The option "-demuxers" of the ff* tools will display the list of enabled demuxers. Use "-formats" to view a combined list of
       enabled demuxers and muxers.

       The description of some of the currently available demuxers follows.

   aa
       Audible Format 2, 3, and 4 demuxer.

       This demuxer is used to demux Audible Format 2, 3, and 4 (.aa) files.

   aac
       Raw Audio Data Transport Stream AAC demuxer.

       This demuxer is used to demux an ADTS input containing a single AAC stream alongwith any ID3v1/2 or APE tags in it.

   apng
       Animated Portable Network Graphics demuxer.

       This demuxer is used to demux APNG files.  All headers, but the PNG signature, up to (but not including) the first fcTL
       chunk are transmitted as extradata.  Frames are then split as being all the chunks between two fcTL ones, or between the
       last fcTL and IEND chunks.

       -ignore_loop bool
           Ignore the loop variable in the file if set. Default is enabled.

       -max_fps int
           Maximum framerate in frames per second. Default of 0 imposes no limit.

       -default_fps int
           Default framerate in frames per second when none is specified in the file (0 meaning as fast as possible). Default is
           15.

   asf
       Advanced Systems Format demuxer.

       This demuxer is used to demux ASF files and MMS network streams.

       -no_resync_search bool
           Do not try to resynchronize by looking for a certain optional start code.

   concat
       Virtual concatenation script demuxer.

       This demuxer reads a list of files and other directives from a text file and demuxes them one after the other, as if all
       their packets had been muxed together.

       The timestamps in the files are adjusted so that the first file starts at 0 and each next file starts where the previous one
       finishes. Note that it is done globally and may cause gaps if all streams do not have exactly the same length.

       All files must have the same streams (same codecs, same time base, etc.).

       The duration of each file is used to adjust the timestamps of the next file: if the duration is incorrect (because it was
       computed using the bit-rate or because the file is truncated, for example), it can cause artifacts. The "duration" directive
       can be used to override the duration stored in each file.

       Syntax

       The script is a text file in extended-ASCII, with one directive per line.  Empty lines, leading spaces and lines starting
       with '#' are ignored. The following directive is recognized:

       "file path"
           Path to a file to read; special characters and spaces must be escaped with backslash or single quotes.

           All subsequent file-related directives apply to that file.

       "ffconcat version 1.0"
           Identify the script type and version.

           To make FFmpeg recognize the format automatically, this directive must appear exactly as is (no extra space or byte-
           order-mark) on the very first line of the script.

       "duration dur"
           Duration of the file. This information can be specified from the file; specifying it here may be more efficient or help
           if the information from the file is not available or accurate.

           If the duration is set for all files, then it is possible to seek in the whole concatenated video.

       "inpoint timestamp"
           In point of the file. When the demuxer opens the file it instantly seeks to the specified timestamp. Seeking is done so
           that all streams can be presented successfully at In point.

           This directive works best with intra frame codecs, because for non-intra frame ones you will usually get extra packets
           before the actual In point and the decoded content will most likely contain frames before In point too.

           For each file, packets before the file In point will have timestamps less than the calculated start timestamp of the
           file (negative in case of the first file), and the duration of the files (if not specified by the "duration" directive)
           will be reduced based on their specified In point.

           Because of potential packets before the specified In point, packet timestamps may overlap between two concatenated
           files.

       "outpoint timestamp"
           Out point of the file. When the demuxer reaches the specified decoding timestamp in any of the streams, it handles it as
           an end of file condition and skips the current and all the remaining packets from all streams.

           Out point is exclusive, which means that the demuxer will not output packets with a decoding timestamp greater or equal
           to Out point.

           This directive works best with intra frame codecs and formats where all streams are tightly interleaved. For non-intra
           frame codecs you will usually get additional packets with presentation timestamp after Out point therefore the decoded
           content will most likely contain frames after Out point too. If your streams are not tightly interleaved you may not get
           all the packets from all streams before Out point and you may only will be able to decode the earliest stream until Out
           point.

           The duration of the files (if not specified by the "duration" directive) will be reduced based on their specified Out
           point.

       "file_packet_metadata key=value"
           Metadata of the packets of the file. The specified metadata will be set for each file packet. You can specify this
           directive multiple times to add multiple metadata entries.  This directive is deprecated, use "file_packet_meta"
           instead.

       "file_packet_meta key value"
           Metadata of the packets of the file. The specified metadata will be set for each file packet. You can specify this
           directive multiple times to add multiple metadata entries.

       "option key value"
           Option to access, open and probe the file.  Can be present multiple times.

       "stream"
           Introduce a stream in the virtual file.  All subsequent stream-related directives apply to the last introduced stream.
           Some streams properties must be set in order to allow identifying the matching streams in the subfiles.  If no streams
           are defined in the script, the streams from the first file are copied.

       "exact_stream_id id"
           Set the id of the stream.  If this directive is given, the string with the corresponding id in the subfiles will be
           used.  This is especially useful for MPEG-PS (VOB) files, where the order of the streams is not reliable.

       "stream_meta key value"
           Metadata for the stream.  Can be present multiple times.

       "stream_codec value"
           Codec for the stream.

       "stream_extradata hex_string"
           Extradata for the string, encoded in hexadecimal.

       "chapter id start end"
           Add a chapter. id is an unique identifier, possibly small and consecutive.

       Options

       This demuxer accepts the following option:

       safe
           If set to 1, reject unsafe file paths and directives.  A file path is considered safe if it does not contain a protocol
           specification and is relative and all components only contain characters from the portable character set (letters,
           digits, period, underscore and hyphen) and have no period at the beginning of a component.

           If set to 0, any file name is accepted.

           The default is 1.

       auto_convert
           If set to 1, try to perform automatic conversions on packet data to make the streams concatenable.  The default is 1.

           Currently, the only conversion is adding the h264_mp4toannexb bitstream filter to H.264 streams in MP4 format. This is
           necessary in particular if there are resolution changes.

       segment_time_metadata
           If set to 1, every packet will contain the lavf.concat.start_time and the lavf.concat.duration packet metadata values
           which are the start_time and the duration of the respective file segments in the concatenated output expressed in
           microseconds. The duration metadata is only set if it is known based on the concat file.  The default is 0.

       Examples

       •   Use absolute filenames and include some comments:

                   # my first filename
                   file /mnt/share/file-1.wav
                   # my second filename including whitespace
                   file '/mnt/share/file 2.wav'
                   # my third filename including whitespace plus single quote
                   file '/mnt/share/file 3'\''.wav'

       •   Allow for input format auto-probing, use safe filenames and set the duration of the first file:

                   ffconcat version 1.0

                   file file-1.wav
                   duration 20.0

                   file subdir/file-2.wav

   dash
       Dynamic Adaptive Streaming over HTTP demuxer.

       This demuxer presents all AVStreams found in the manifest.  By setting the discard flags on AVStreams the caller can decide
       which streams to actually receive.  Each stream mirrors the "id" and "bandwidth" properties from the "<Representation>" as
       metadata keys named "id" and "variant_bitrate" respectively.

       Options

       This demuxer accepts the following option:

       cenc_decryption_key
           16-byte key, in hex, to decrypt files encrypted using ISO Common Encryption (CENC/AES-128 CTR; ISO/IEC 23001-7).

   imf
       Interoperable Master Format demuxer.

       This demuxer presents audio and video streams found in an IMF Composition.

   flv, live_flv, kux
       Adobe Flash Video Format demuxer.

       This demuxer is used to demux FLV files and RTMP network streams. In case of live network streams, if you force format, you
       may use live_flv option instead of flv to survive timestamp discontinuities.  KUX is a flv variant used on the Youku
       platform.

               ffmpeg -f flv -i myfile.flv ...
               ffmpeg -f live_flv -i rtmp://<any.server>/anything/key ....

       -flv_metadata bool
           Allocate the streams according to the onMetaData array content.

       -flv_ignore_prevtag bool
           Ignore the size of previous tag value.

       -flv_full_metadata bool
           Output all context of the onMetadata.

   gif
       Animated GIF demuxer.

       It accepts the following options:

       min_delay
           Set the minimum valid delay between frames in hundredths of seconds.  Range is 0 to 6000. Default value is 2.

       max_gif_delay
           Set the maximum valid delay between frames in hundredth of seconds.  Range is 0 to 65535. Default value is 65535 (nearly
           eleven minutes), the maximum value allowed by the specification.

       default_delay
           Set the default delay between frames in hundredths of seconds.  Range is 0 to 6000. Default value is 10.

       ignore_loop
           GIF files can contain information to loop a certain number of times (or infinitely). If ignore_loop is set to 1, then
           the loop setting from the input will be ignored and looping will not occur. If set to 0, then looping will occur and
           will cycle the number of times according to the GIF. Default value is 1.

       For example, with the overlay filter, place an infinitely looping GIF over another video:

               ffmpeg -i input.mp4 -ignore_loop 0 -i input.gif -filter_complex overlay=shortest=1 out.mkv

       Note that in the above example the shortest option for overlay filter is used to end the output video at the length of the
       shortest input file, which in this case is input.mp4 as the GIF in this example loops infinitely.

   hls
       HLS demuxer

       Apple HTTP Live Streaming demuxer.

       This demuxer presents all AVStreams from all variant streams.  The id field is set to the bitrate variant index number. By
       setting the discard flags on AVStreams (by pressing 'a' or 'v' in ffplay), the caller can decide which variant streams to
       actually receive.  The total bitrate of the variant that the stream belongs to is available in a metadata key named
       "variant_bitrate".

       It accepts the following options:

       live_start_index
           segment index to start live streams at (negative values are from the end).

       prefer_x_start
           prefer to use #EXT-X-START if it's in playlist instead of live_start_index.

       allowed_extensions
           ',' separated list of file extensions that hls is allowed to access.

       max_reload
           Maximum number of times a insufficient list is attempted to be reloaded.  Default value is 1000.

       m3u8_hold_counters
           The maximum number of times to load m3u8 when it refreshes without new segments.  Default value is 1000.

       http_persistent
           Use persistent HTTP connections. Applicable only for HTTP streams.  Enabled by default.

       http_multiple
           Use multiple HTTP connections for downloading HTTP segments.  Enabled by default for HTTP/1.1 servers.

       http_seekable
           Use HTTP partial requests for downloading HTTP segments.  0 = disable, 1 = enable, -1 = auto, Default is auto.

       seg_format_options
           Set options for the demuxer of media segments using a list of key=value pairs separated by ":".

   image2
       Image file demuxer.

       This demuxer reads from a list of image files specified by a pattern.  The syntax and meaning of the pattern is specified by
       the option pattern_type.

       The pattern may contain a suffix which is used to automatically determine the format of the images contained in the files.

       The size, the pixel format, and the format of each image must be the same for all the files in the sequence.

       This demuxer accepts the following options:

       framerate
           Set the frame rate for the video stream. It defaults to 25.

       loop
           If set to 1, loop over the input. Default value is 0.

       pattern_type
           Select the pattern type used to interpret the provided filename.

           pattern_type accepts one of the following values.

           none
               Disable pattern matching, therefore the video will only contain the specified image. You should use this option if
               you do not want to create sequences from multiple images and your filenames may contain special pattern characters.

           sequence
               Select a sequence pattern type, used to specify a sequence of files indexed by sequential numbers.

               A sequence pattern may contain the string "%d" or "%0Nd", which specifies the position of the characters
               representing a sequential number in each filename matched by the pattern. If the form "%d0Nd" is used, the string
               representing the number in each filename is 0-padded and N is the total number of 0-padded digits representing the
               number. The literal character '%' can be specified in the pattern with the string "%%".

               If the sequence pattern contains "%d" or "%0Nd", the first filename of the file list specified by the pattern must
               contain a number inclusively contained between start_number and start_number+start_number_range-1, and all the
               following numbers must be sequential.

               For example the pattern "img-%03d.bmp" will match a sequence of filenames of the form img-001.bmp, img-002.bmp, ...,
               img-010.bmp, etc.; the pattern "i%%m%%g-%d.jpg" will match a sequence of filenames of the form i%m%g-1.jpg,
               i%m%g-2.jpg, ..., i%m%g-10.jpg, etc.

               Note that the pattern must not necessarily contain "%d" or "%0Nd", for example to convert a single image file
               img.jpeg you can employ the command:

                       ffmpeg -i img.jpeg img.png

           glob
               Select a glob wildcard pattern type.

               The pattern is interpreted like a "glob()" pattern. This is only selectable if libavformat was compiled with
               globbing support.

           glob_sequence (deprecated, will be removed)
               Select a mixed glob wildcard/sequence pattern.

               If your version of libavformat was compiled with globbing support, and the provided pattern contains at least one
               glob meta character among "%*?[]{}" that is preceded by an unescaped "%", the pattern is interpreted like a "glob()"
               pattern, otherwise it is interpreted like a sequence pattern.

               All glob special characters "%*?[]{}" must be prefixed with "%". To escape a literal "%" you shall use "%%".

               For example the pattern "foo-%*.jpeg" will match all the filenames prefixed by "foo-" and terminating with ".jpeg",
               and "foo-%?%?%?.jpeg" will match all the filenames prefixed with "foo-", followed by a sequence of three characters,
               and terminating with ".jpeg".

               This pattern type is deprecated in favor of glob and sequence.

           Default value is glob_sequence.

       pixel_format
           Set the pixel format of the images to read. If not specified the pixel format is guessed from the first image file in
           the sequence.

       start_number
           Set the index of the file matched by the image file pattern to start to read from. Default value is 0.

       start_number_range
           Set the index interval range to check when looking for the first image file in the sequence, starting from start_number.
           Default value is 5.

       ts_from_file
           If set to 1, will set frame timestamp to modification time of image file. Note that monotonity of timestamps is not
           provided: images go in the same order as without this option. Default value is 0.  If set to 2, will set frame timestamp
           to the modification time of the image file in nanosecond precision.

       video_size
           Set the video size of the images to read. If not specified the video size is guessed from the first image file in the
           sequence.

       export_path_metadata
           If set to 1, will add two extra fields to the metadata found in input, making them also available for other filters (see
           drawtext filter for examples). Default value is 0. The extra fields are described below:

           lavf.image2dec.source_path
               Corresponds to the full path to the input file being read.

           lavf.image2dec.source_basename
               Corresponds to the name of the file being read.

       Examples

       •   Use ffmpeg for creating a video from the images in the file sequence img-001.jpeg, img-002.jpeg, ..., assuming an input
           frame rate of 10 frames per second:

                   ffmpeg -framerate 10 -i 'img-%03d.jpeg' out.mkv

       •   As above, but start by reading from a file with index 100 in the sequence:

                   ffmpeg -framerate 10 -start_number 100 -i 'img-%03d.jpeg' out.mkv

       •   Read images matching the "*.png" glob pattern , that is all the files terminating with the ".png" suffix:

                   ffmpeg -framerate 10 -pattern_type glob -i "*.png" out.mkv

   libgme
       The Game Music Emu library is a collection of video game music file emulators.

       See <https://bitbucket.org/mpyne/game-music-emu/overview> for more information.

       It accepts the following options:

       track_index
           Set the index of which track to demux. The demuxer can only export one track.  Track indexes start at 0. Default is to
           pick the first track. Number of tracks is exported as tracks metadata entry.

       sample_rate
           Set the sampling rate of the exported track. Range is 1000 to 999999. Default is 44100.

       max_size (bytes)
           The demuxer buffers the entire file into memory. Adjust this value to set the maximum buffer size, which in turn, acts
           as a ceiling for the size of files that can be read.  Default is 50 MiB.

   libmodplug
       ModPlug based module demuxer

       See <https://github.com/Konstanty/libmodplug>

       It will export one 2-channel 16-bit 44.1 kHz audio stream.  Optionally, a "pal8" 16-color video stream can be exported with
       or without printed metadata.

       It accepts the following options:

       noise_reduction
           Apply a simple low-pass filter. Can be 1 (on) or 0 (off). Default is 0.

       reverb_depth
           Set amount of reverb. Range 0-100. Default is 0.

       reverb_delay
           Set delay in ms, clamped to 40-250 ms. Default is 0.

       bass_amount
           Apply bass expansion a.k.a. XBass or megabass. Range is 0 (quiet) to 100 (loud). Default is 0.

       bass_range
           Set cutoff i.e. upper-bound for bass frequencies. Range is 10-100 Hz. Default is 0.

       surround_depth
           Apply a Dolby Pro-Logic surround effect. Range is 0 (quiet) to 100 (heavy). Default is 0.

       surround_delay
           Set surround delay in ms, clamped to 5-40 ms. Default is 0.

       max_size
           The demuxer buffers the entire file into memory. Adjust this value to set the maximum buffer size, which in turn, acts
           as a ceiling for the size of files that can be read. Range is 0 to 100 MiB.  0 removes buffer size limit (not
           recommended). Default is 5 MiB.

       video_stream_expr
           String which is evaluated using the eval API to assign colors to the generated video stream.  Variables which can be
           used are "x", "y", "w", "h", "t", "speed", "tempo", "order", "pattern" and "row".

       video_stream
           Generate video stream. Can be 1 (on) or 0 (off). Default is 0.

       video_stream_w
           Set video frame width in 'chars' where one char indicates 8 pixels. Range is 20-512. Default is 30.

       video_stream_h
           Set video frame height in 'chars' where one char indicates 8 pixels. Range is 20-512. Default is 30.

       video_stream_ptxt
           Print metadata on video stream. Includes "speed", "tempo", "order", "pattern", "row" and "ts" (time in ms). Can be 1
           (on) or 0 (off). Default is 1.

   libopenmpt
       libopenmpt based module demuxer

       See <https://lib.openmpt.org/libopenmpt/> for more information.

       Some files have multiple subsongs (tracks) this can be set with the subsong option.

       It accepts the following options:

       subsong
           Set the subsong index. This can be either  'all', 'auto', or the index of the subsong. Subsong indexes start at 0. The
           default is 'auto'.

           The default value is to let libopenmpt choose.

       layout
           Set the channel layout. Valid values are 1, 2, and 4 channel layouts.  The default value is STEREO.

       sample_rate
           Set the sample rate for libopenmpt to output.  Range is from 1000 to INT_MAX. The value default is 48000.

   mov/mp4/3gp
       Demuxer for Quicktime File Format & ISO/IEC Base Media File Format (ISO/IEC 14496-12 or MPEG-4 Part 12, ISO/IEC 15444-12 or
       JPEG 2000 Part 12).

       Registered extensions: mov, mp4, m4a, 3gp, 3g2, mj2, psp, m4b, ism, ismv, isma, f4v

       Options

       This demuxer accepts the following options:

       enable_drefs
           Enable loading of external tracks, disabled by default.  Enabling this can theoretically leak information in some use
           cases.

       use_absolute_path
           Allows loading of external tracks via absolute paths, disabled by default.  Enabling this poses a security risk. It
           should only be enabled if the source is known to be non-malicious.

       seek_streams_individually
           When seeking, identify the closest point in each stream individually and demux packets in that stream from identified
           point. This can lead to a different sequence of packets compared to demuxing linearly from the beginning. Default is
           true.

       ignore_editlist
           Ignore any edit list atoms. The demuxer, by default, modifies the stream index to reflect the timeline described by the
           edit list. Default is false.

       advanced_editlist
           Modify the stream index to reflect the timeline described by the edit list. "ignore_editlist" must be set to false for
           this option to be effective.  If both "ignore_editlist" and this option are set to false, then only the start of the
           stream index is modified to reflect initial dwell time or starting timestamp described by the edit list. Default is
           true.

       ignore_chapters
           Don't parse chapters. This includes GoPro 'HiLight' tags/moments. Note that chapters are only parsed when input is
           seekable. Default is false.

       use_mfra_for
           For seekable fragmented input, set fragment's starting timestamp from media fragment random access box, if present.

           Following options are available:

           auto
               Auto-detect whether to set mfra timestamps as PTS or DTS (default)

           dts Set mfra timestamps as DTS

           pts Set mfra timestamps as PTS

           0   Don't use mfra box to set timestamps

       use_tfdt
           For fragmented input, set fragment's starting timestamp to "baseMediaDecodeTime" from the "tfdt" box.  Default is
           enabled, which will prefer to use the "tfdt" box to set DTS. Disable to use the "earliest_presentation_time" from the
           "sidx" box.  In either case, the timestamp from the "mfra" box will be used if it's available and "use_mfra_for" is set
           to pts or dts.

       export_all
           Export unrecognized boxes within the udta box as metadata entries. The first four characters of the box type are set as
           the key. Default is false.

       export_xmp
           Export entire contents of XMP_ box and uuid box as a string with key "xmp". Note that if "export_all" is set and this
           option isn't, the contents of XMP_ box are still exported but with key "XMP_". Default is false.

       activation_bytes
           4-byte key required to decrypt Audible AAX and AAX+ files. See Audible AAX subsection below.

       audible_fixed_key
           Fixed key used for handling Audible AAX/AAX+ files. It has been pre-set so should not be necessary to specify.

       decryption_key
           16-byte key, in hex, to decrypt files encrypted using ISO Common Encryption (CENC/AES-128 CTR; ISO/IEC 23001-7).

       max_stts_delta
           Very high sample deltas written in a trak's stts box may occasionally be intended but usually they are written in error
           or used to store a negative value for dts correction when treated as signed 32-bit integers. This option lets the user
           set an upper limit, beyond which the delta is clamped to 1. Values greater than the limit if negative when cast to int32
           are used to adjust onward dts.

           Unit is the track time scale. Range is 0 to UINT_MAX. Default is "UINT_MAX - 48000*10" which allows upto a 10 second dts
           correction for 48 kHz audio streams while accommodating 99.9% of "uint32" range.

       Audible AAX

       Audible AAX files are encrypted M4B files, and they can be decrypted by specifying a 4 byte activation secret.

               ffmpeg -activation_bytes 1CEB00DA -i test.aax -vn -c:a copy output.mp4

   mpegts
       MPEG-2 transport stream demuxer.

       This demuxer accepts the following options:

       resync_size
           Set size limit for looking up a new synchronization. Default value is 65536.

       skip_unknown_pmt
           Skip PMTs for programs not defined in the PAT. Default value is 0.

       fix_teletext_pts
           Override teletext packet PTS and DTS values with the timestamps calculated from the PCR of the first program which the
           teletext stream is part of and is not discarded. Default value is 1, set this option to 0 if you want your teletext
           packet PTS and DTS values untouched.

       ts_packetsize
           Output option carrying the raw packet size in bytes.  Show the detected raw packet size, cannot be set by the user.

       scan_all_pmts
           Scan and combine all PMTs. The value is an integer with value from -1 to 1 (-1 means automatic setting, 1 means enabled,
           0 means disabled). Default value is -1.

       merge_pmt_versions
           Re-use existing streams when a PMT's version is updated and elementary streams move to different PIDs. Default value is
           0.

       max_packet_size
           Set maximum size, in bytes, of packet emitted by the demuxer. Payloads above this size are split across multiple
           packets. Range is 1 to INT_MAX/2. Default is 204800 bytes.

   mpjpeg
       MJPEG encapsulated in multi-part MIME demuxer.

       This demuxer allows reading of MJPEG, where each frame is represented as a part of multipart/x-mixed-replace stream.

       strict_mime_boundary
           Default implementation applies a relaxed standard to multi-part MIME boundary detection, to prevent regression with
           numerous existing endpoints not generating a proper MIME MJPEG stream. Turning this option on by setting it to 1 will
           result in a stricter check of the boundary value.

   rawvideo
       Raw video demuxer.

       This demuxer allows one to read raw video data. Since there is no header specifying the assumed video parameters, the user
       must specify them in order to be able to decode the data correctly.

       This demuxer accepts the following options:

       framerate
           Set input video frame rate. Default value is 25.

       pixel_format
           Set the input video pixel format. Default value is "yuv420p".

       video_size
           Set the input video size. This value must be specified explicitly.

       For example to read a rawvideo file input.raw with ffplay, assuming a pixel format of "rgb24", a video size of "320x240",
       and a frame rate of 10 images per second, use the command:

               ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw

   sbg
       SBaGen script demuxer.

       This demuxer reads the script language used by SBaGen <http://uazu.net/sbagen/> to generate binaural beats sessions. A SBG
       script looks like that:

               -SE
               a: 300-2.5/3 440+4.5/0
               b: 300-2.5/0 440+4.5/3
               off: -
               NOW      == a
               +0:07:00 == b
               +0:14:00 == a
               +0:21:00 == b
               +0:30:00    off

       A SBG script can mix absolute and relative timestamps. If the script uses either only absolute timestamps (including the
       script start time) or only relative ones, then its layout is fixed, and the conversion is straightforward. On the other
       hand, if the script mixes both kind of timestamps, then the NOW reference for relative timestamps will be taken from the
       current time of day at the time the script is read, and the script layout will be frozen according to that reference. That
       means that if the script is directly played, the actual times will match the absolute timestamps up to the sound
       controller's clock accuracy, but if the user somehow pauses the playback or seeks, all times will be shifted accordingly.

   tedcaptions
       JSON captions used for <http://www.ted.com/>.

       TED does not provide links to the captions, but they can be guessed from the page. The file tools/bookmarklets.html from the
       FFmpeg source tree contains a bookmarklet to expose them.

       This demuxer accepts the following option:

       start_time
           Set the start time of the TED talk, in milliseconds. The default is 15000 (15s). It is used to sync the captions with
           the downloadable videos, because they include a 15s intro.

       Example: convert the captions to a format most players understand:

               ffmpeg -i http://www.ted.com/talks/subtitles/id/1/lang/en talk1-en.srt

   vapoursynth
       Vapoursynth wrapper.

       Due to security concerns, Vapoursynth scripts will not be autodetected so the input format has to be forced. For ff* CLI
       tools, add "-f vapoursynth" before the input "-i yourscript.vpy".

       This demuxer accepts the following option:

       max_script_size
           The demuxer buffers the entire script into memory. Adjust this value to set the maximum buffer size, which in turn, acts
           as a ceiling for the size of scripts that can be read.  Default is 1 MiB.

METADATA
       FFmpeg is able to dump metadata from media files into a simple UTF-8-encoded INI-like text file and then load it back using
       the metadata muxer/demuxer.

       The file format is as follows:

       1.  A file consists of a header and a number of metadata tags divided into sections, each on its own line.

       2.  The header is a ;FFMETADATA string, followed by a version number (now 1).

       3.  Metadata tags are of the form key=value

       4.  Immediately after header follows global metadata

       5.  After global metadata there may be sections with per-stream/per-chapter metadata.

       6.  A section starts with the section name in uppercase (i.e. STREAM or CHAPTER) in brackets ([, ]) and ends with next
           section or end of file.

       7.  At the beginning of a chapter section there may be an optional timebase to be used for start/end values. It must be in
           form TIMEBASE=num/den, where num and den are integers. If the timebase is missing then start/end times are assumed to be
           in nanoseconds.

           Next a chapter section must contain chapter start and end times in form START=num, END=num, where num is a positive
           integer.

       8.  Empty lines and lines starting with ; or # are ignored.

       9.  Metadata keys or values containing special characters (=, ;, #, \ and a newline) must be escaped with a backslash \.

       10. Note that whitespace in metadata (e.g. foo = bar) is considered to be a part of the tag (in the example above key is foo
           , value is
            bar).

       A ffmetadata file might look like this:

               ;FFMETADATA1
               title=bike\\shed
               ;this is a comment
               artist=FFmpeg troll team

               [CHAPTER]
               TIMEBASE=1/1000
               START=0
               #chapter ends at 0:01:00
               END=60000
               title=chapter \#1
               [STREAM]
               title=multi\
               line

       By using the ffmetadata muxer and demuxer it is possible to extract metadata from an input file to an ffmetadata file, and
       then transcode the file into an output file with the edited ffmetadata file.

       Extracting an ffmetadata file with ffmpeg goes as follows:

               ffmpeg -i INPUT -f ffmetadata FFMETADATAFILE

       Reinserting edited metadata information from the FFMETADATAFILE file can be done as:

               ffmpeg -i INPUT -i FFMETADATAFILE -map_metadata 1 -codec copy OUTPUT

PROTOCOL OPTIONS
       The libavformat library provides some generic global options, which can be set on all the protocols. In addition each
       protocol may support so-called private options, which are specific for that component.

       Options may be set by specifying -option value in the FFmpeg tools, or by setting the value explicitly in the
       "AVFormatContext" options or using the libavutil/opt.h API for programmatic use.

       The list of supported options follows:

       protocol_whitelist list (input)
           Set a ","-separated list of allowed protocols. "ALL" matches all protocols. Protocols prefixed by "-" are disabled.  All
           protocols are allowed by default but protocols used by an another protocol (nested protocols) are restricted to a per
           protocol subset.

PROTOCOLS
       Protocols are configured elements in FFmpeg that enable access to resources that require specific protocols.

       When you configure your FFmpeg build, all the supported protocols are enabled by default. You can list all available ones
       using the configure option "--list-protocols".

       You can disable all the protocols using the configure option "--disable-protocols", and selectively enable a protocol using
       the option "--enable-protocol=PROTOCOL", or you can disable a particular protocol using the option
       "--disable-protocol=PROTOCOL".

       The option "-protocols" of the ff* tools will display the list of supported protocols.

       All protocols accept the following options:

       rw_timeout
           Maximum time to wait for (network) read/write operations to complete, in microseconds.

       A description of the currently available protocols follows.

   amqp
       Advanced Message Queueing Protocol (AMQP) version 0-9-1 is a broker based publish-subscribe communication protocol.

       FFmpeg must be compiled with --enable-librabbitmq to support AMQP. A separate AMQP broker must also be run. An example open-
       source AMQP broker is RabbitMQ.

       After starting the broker, an FFmpeg client may stream data to the broker using the command:

               ffmpeg -re -i input -f mpegts amqp://[[user]:[password]@]hostname[:port][/vhost]

       Where hostname and port (default is 5672) is the address of the broker. The client may also set a user/password for
       authentication. The default for both fields is "guest". Name of virtual host on broker can be set with vhost. The default
       value is "/".

       Muliple subscribers may stream from the broker using the command:

               ffplay amqp://[[user]:[password]@]hostname[:port][/vhost]

       In RabbitMQ all data published to the broker flows through a specific exchange, and each subscribing client has an assigned
       queue/buffer. When a packet arrives at an exchange, it may be copied to a client's queue depending on the exchange and
       routing_key fields.

       The following options are supported:

       exchange
           Sets the exchange to use on the broker. RabbitMQ has several predefined exchanges: "amq.direct" is the default exchange,
           where the publisher and subscriber must have a matching routing_key; "amq.fanout" is the same as a broadcast operation
           (i.e. the data is forwarded to all queues on the fanout exchange independent of the routing_key); and "amq.topic" is
           similar to "amq.direct", but allows for more complex pattern matching (refer to the RabbitMQ documentation).

       routing_key
           Sets the routing key. The default value is "amqp". The routing key is used on the "amq.direct" and "amq.topic" exchanges
           to decide whether packets are written to the queue of a subscriber.

       pkt_size
           Maximum size of each packet sent/received to the broker. Default is 131072.  Minimum is 4096 and max is any large value
           (representable by an int). When receiving packets, this sets an internal buffer size in FFmpeg. It should be equal to or
           greater than the size of the published packets to the broker. Otherwise the received message may be truncated causing
           decoding errors.

       connection_timeout
           The timeout in seconds during the initial connection to the broker. The default value is rw_timeout, or 5 seconds if
           rw_timeout is not set.

       delivery_mode mode
           Sets the delivery mode of each message sent to broker.  The following values are accepted:

           persistent
               Delivery mode set to "persistent" (2). This is the default value.  Messages may be written to the broker's disk
               depending on its setup.

           non-persistent
               Delivery mode set to "non-persistent" (1).  Messages will stay in broker's memory unless the broker is under memory
               pressure.

   async
       Asynchronous data filling wrapper for input stream.

       Fill data in a background thread, to decouple I/O operation from demux thread.

               async:<URL>
               async:http://host/resource
               async:cache:http://host/resource

   bluray
       Read BluRay playlist.

       The accepted options are:

       angle
           BluRay angle

       chapter
           Start chapter (1...N)

       playlist
           Playlist to read (BDMV/PLAYLIST/?????.mpls)

       Examples:

       Read longest playlist from BluRay mounted to /mnt/bluray:

               bluray:/mnt/bluray

       Read angle 2 of playlist 4 from BluRay mounted to /mnt/bluray, start from chapter 2:

               -playlist 4 -angle 2 -chapter 2 bluray:/mnt/bluray

   cache
       Caching wrapper for input stream.

       Cache the input stream to temporary file. It brings seeking capability to live streams.

       The accepted options are:

       read_ahead_limit
           Amount in bytes that may be read ahead when seeking isn't supported. Range is -1 to INT_MAX.  -1 for unlimited. Default
           is 65536.

       URL Syntax is

               cache:<URL>

   concat
       Physical concatenation protocol.

       Read and seek from many resources in sequence as if they were a unique resource.

       A URL accepted by this protocol has the syntax:

               concat:<URL1>|<URL2>|...|<URLN>

       where URL1, URL2, ..., URLN are the urls of the resource to be concatenated, each one possibly specifying a distinct
       protocol.

       For example to read a sequence of files split1.mpeg, split2.mpeg, split3.mpeg with ffplay use the command:

               ffplay concat:split1.mpeg\|split2.mpeg\|split3.mpeg

       Note that you may need to escape the character "|" which is special for many shells.

   concatf
       Physical concatenation protocol using a line break delimited list of resources.

       Read and seek from many resources in sequence as if they were a unique resource.

       A URL accepted by this protocol has the syntax:

               concatf:<URL>

       where URL is the url containing a line break delimited list of resources to be concatenated, each one possibly specifying a
       distinct protocol. Special characters must be escaped with backslash or single quotes. See the "Quoting and escaping"
       section in the ffmpeg-utils(1) manual.

       For example to read a sequence of files split1.mpeg, split2.mpeg, split3.mpeg listed in separate lines within a file
       split.txt with ffplay use the command:

               ffplay concatf:split.txt

       Where split.txt contains the lines:

               split1.mpeg
               split2.mpeg
               split3.mpeg

   crypto
       AES-encrypted stream reading protocol.

       The accepted options are:

       key Set the AES decryption key binary block from given hexadecimal representation.

       iv  Set the AES decryption initialization vector binary block from given hexadecimal representation.

       Accepted URL formats:

               crypto:<URL>
               crypto+<URL>

   data
       Data in-line in the URI. See <http://en.wikipedia.org/wiki/Data_URI_scheme>.

       For example, to convert a GIF file given inline with ffmpeg:

               ffmpeg -i "data:image/gif;base64,R0lGODdhCAAIAMIEAAAAAAAA//8AAP//AP///////////////ywAAAAACAAIAAADF0gEDLojDgdGiJdJqUX02iB4E8Q9jUMkADs=" smiley.png

   file
       File access protocol.

       Read from or write to a file.

       A file URL can have the form:

               file:<filename>

       where filename is the path of the file to read.

       An URL that does not have a protocol prefix will be assumed to be a file URL. Depending on the build, an URL that looks like
       a Windows path with the drive letter at the beginning will also be assumed to be a file URL (usually not the case in builds
       for unix-like systems).

       For example to read from a file input.mpeg with ffmpeg use the command:

               ffmpeg -i file:input.mpeg output.mpeg

       This protocol accepts the following options:

       truncate
           Truncate existing files on write, if set to 1. A value of 0 prevents truncating. Default value is 1.

       blocksize
           Set I/O operation maximum block size, in bytes. Default value is "INT_MAX", which results in not limiting the requested
           block size.  Setting this value reasonably low improves user termination request reaction time, which is valuable for
           files on slow medium.

       follow
           If set to 1, the protocol will retry reading at the end of the file, allowing reading files that still are being
           written. In order for this to terminate, you either need to use the rw_timeout option, or use the interrupt callback
           (for API users).

       seekable
           Controls if seekability is advertised on the file. 0 means non-seekable, -1 means auto (seekable for normal files, non-
           seekable for named pipes).

           Many demuxers handle seekable and non-seekable resources differently, overriding this might speed up opening certain
           files at the cost of losing some features (e.g. accurate seeking).

   ftp
       FTP (File Transfer Protocol).

       Read from or write to remote resources using FTP protocol.

       Following syntax is required.

               ftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg

       This protocol accepts the following options.

       timeout
           Set timeout in microseconds of socket I/O operations used by the underlying low level operation. By default it is set to
           -1, which means that the timeout is not specified.

       ftp-user
           Set a user to be used for authenticating to the FTP server. This is overridden by the user in the FTP URL.

       ftp-password
           Set a password to be used for authenticating to the FTP server. This is overridden by the password in the FTP URL, or by
           ftp-anonymous-password if no user is set.

       ftp-anonymous-password
           Password used when login as anonymous user. Typically an e-mail address should be used.

       ftp-write-seekable
           Control seekability of connection during encoding. If set to 1 the resource is supposed to be seekable, if set to 0 it
           is assumed not to be seekable. Default value is 0.

       NOTE: Protocol can be used as output, but it is recommended to not do it, unless special care is taken (tests, customized
       server configuration etc.). Different FTP servers behave in different way during seek operation. ff* tools may produce
       incomplete content due to server limitations.

   gopher
       Gopher protocol.

   gophers
       Gophers protocol.

       The Gopher protocol with TLS encapsulation.

   hls
       Read Apple HTTP Live Streaming compliant segmented stream as a uniform one. The M3U8 playlists describing the segments can
       be remote HTTP resources or local files, accessed using the standard file protocol.  The nested protocol is declared by
       specifying "+proto" after the hls URI scheme name, where proto is either "file" or "http".

               hls+http://host/path/to/remote/resource.m3u8
               hls+file://path/to/local/resource.m3u8

       Using this protocol is discouraged - the hls demuxer should work just as well (if not, please report the issues) and is more
       complete.  To use the hls demuxer instead, simply use the direct URLs to the m3u8 files.

   http
       HTTP (Hyper Text Transfer Protocol).

       This protocol accepts the following options:

       seekable
           Control seekability of connection. If set to 1 the resource is supposed to be seekable, if set to 0 it is assumed not to
           be seekable, if set to -1 it will try to autodetect if it is seekable. Default value is -1.

       chunked_post
           If set to 1 use chunked Transfer-Encoding for posts, default is 1.

       content_type
           Set a specific content type for the POST messages or for listen mode.

       http_proxy
           set HTTP proxy to tunnel through e.g. http://example.com:1234

       headers
           Set custom HTTP headers, can override built in default headers. The value must be a string encoding the headers.

       multiple_requests
           Use persistent connections if set to 1, default is 0.

       post_data
           Set custom HTTP post data.

       referer
           Set the Referer header. Include 'Referer: URL' header in HTTP request.

       user_agent
           Override the User-Agent header. If not specified the protocol will use a string describing the libavformat build.
           ("Lavf/<version>")

       reconnect_at_eof
           If set then eof is treated like an error and causes reconnection, this is useful for live / endless streams.

       reconnect_streamed
           If set then even streamed/non seekable streams will be reconnected on errors.

       reconnect_on_network_error
           Reconnect automatically in case of TCP/TLS errors during connect.

       reconnect_on_http_error
           A comma separated list of HTTP status codes to reconnect on. The list can include specific status codes (e.g. '503') or
           the strings '4xx' / '5xx'.

       reconnect_delay_max
           Sets the maximum delay in seconds after which to give up reconnecting

       mime_type
           Export the MIME type.

       http_version
           Exports the HTTP response version number. Usually "1.0" or "1.1".

       icy If set to 1 request ICY (SHOUTcast) metadata from the server. If the server supports this, the metadata has to be
           retrieved by the application by reading the icy_metadata_headers and icy_metadata_packet options.  The default is 1.

       icy_metadata_headers
           If the server supports ICY metadata, this contains the ICY-specific HTTP reply headers, separated by newline characters.

       icy_metadata_packet
           If the server supports ICY metadata, and icy was set to 1, this contains the last non-empty metadata packet sent by the
           server. It should be polled in regular intervals by applications interested in mid-stream metadata updates.

       cookies
           Set the cookies to be sent in future requests. The format of each cookie is the same as the value of a Set-Cookie HTTP
           response field. Multiple cookies can be delimited by a newline character.

       offset
           Set initial byte offset.

       end_offset
           Try to limit the request to bytes preceding this offset.

       method
           When used as a client option it sets the HTTP method for the request.

           When used as a server option it sets the HTTP method that is going to be expected from the client(s).  If the expected
           and the received HTTP method do not match the client will be given a Bad Request response.  When unset the HTTP method
           is not checked for now. This will be replaced by autodetection in the future.

       listen
           If set to 1 enables experimental HTTP server. This can be used to send data when used as an output option, or read data
           from a client with HTTP POST when used as an input option.  If set to 2 enables experimental multi-client HTTP server.
           This is not yet implemented in ffmpeg.c and thus must not be used as a command line option.

                   # Server side (sending):
                   ffmpeg -i somefile.ogg -c copy -listen 1 -f ogg http://<server>:<port>

                   # Client side (receiving):
                   ffmpeg -i http://<server>:<port> -c copy somefile.ogg

                   # Client can also be done with wget:
                   wget http://<server>:<port> -O somefile.ogg

                   # Server side (receiving):
                   ffmpeg -listen 1 -i http://<server>:<port> -c copy somefile.ogg

                   # Client side (sending):
                   ffmpeg -i somefile.ogg -chunked_post 0 -c copy -f ogg http://<server>:<port>

                   # Client can also be done with wget:
                   wget --post-file=somefile.ogg http://<server>:<port>

       send_expect_100
           Send an Expect: 100-continue header for POST. If set to 1 it will send, if set to 0 it won't, if set to -1 it will try
           to send if it is applicable. Default value is -1.

       auth_type
           Set HTTP authentication type. No option for Digest, since this method requires getting nonce parameters from the server
           first and can't be used straight away like Basic.

           none
               Choose the HTTP authentication type automatically. This is the default.

           basic
               Choose the HTTP basic authentication.

               Basic authentication sends a Base64-encoded string that contains a user name and password for the client. Base64 is
               not a form of encryption and should be considered the same as sending the user name and password in clear text
               (Base64 is a reversible encoding).  If a resource needs to be protected, strongly consider using an authentication
               scheme other than basic authentication. HTTPS/TLS should be used with basic authentication.  Without these
               additional security enhancements, basic authentication should not be used to protect sensitive or valuable
               information.

       HTTP Cookies

       Some HTTP requests will be denied unless cookie values are passed in with the request. The cookies option allows these
       cookies to be specified. At the very least, each cookie must specify a value along with a path and domain.  HTTP requests
       that match both the domain and path will automatically include the cookie value in the HTTP Cookie header field. Multiple
       cookies can be delimited by a newline.

       The required syntax to play a stream specifying a cookie is:

               ffplay -cookies "nlqptid=nltid=tsn; path=/; domain=somedomain.com;" http://somedomain.com/somestream.m3u8

   Icecast
       Icecast protocol (stream to Icecast servers)

       This protocol accepts the following options:

       ice_genre
           Set the stream genre.

       ice_name
           Set the stream name.

       ice_description
           Set the stream description.

       ice_url
           Set the stream website URL.

       ice_public
           Set if the stream should be public.  The default is 0 (not public).

       user_agent
           Override the User-Agent header. If not specified a string of the form "Lavf/<version>" will be used.

       password
           Set the Icecast mountpoint password.

       content_type
           Set the stream content type. This must be set if it is different from audio/mpeg.

       legacy_icecast
           This enables support for Icecast versions < 2.4.0, that do not support the HTTP PUT method but the SOURCE method.

       tls Establish a TLS (HTTPS) connection to Icecast.

               icecast://[<username>[:<password>]@]<server>:<port>/<mountpoint>

   ipfs
       InterPlanetary File System (IPFS) protocol support. One can access files stored on the IPFS network through so-called
       gateways. These are http(s) endpoints.  This protocol wraps the IPFS native protocols (ipfs:// and ipns://) to be sent to
       such a gateway. Users can (and should) host their own node which means this protocol will use one's local gateway to access
       files on the IPFS network.

       If a user doesn't have a node of their own then the public gateway "https://dweb.link" is used by default.

       This protocol accepts the following options:

       gateway
           Defines the gateway to use. When not set, the protocol will first try locating the local gateway by looking at
           $IPFS_GATEWAY, $IPFS_PATH and "$HOME/.ipfs/", in that order. If that fails "https://dweb.link" will be used.

       One can use this protocol in 2 ways. Using IPFS:

               ffplay ipfs://QmbGtJg23skhvFmu9mJiePVByhfzu5rwo74MEkVDYAmF5T

       Or the IPNS protocol (IPNS is mutable IPFS):

               ffplay ipns://QmbGtJg23skhvFmu9mJiePVByhfzu5rwo74MEkVDYAmF5T

   mmst
       MMS (Microsoft Media Server) protocol over TCP.

   mmsh
       MMS (Microsoft Media Server) protocol over HTTP.

       The required syntax is:

               mmsh://<server>[:<port>][/<app>][/<playpath>]

   md5
       MD5 output protocol.

       Computes the MD5 hash of the data to be written, and on close writes this to the designated output or stdout if none is
       specified. It can be used to test muxers without writing an actual file.

       Some examples follow.

               # Write the MD5 hash of the encoded AVI file to the file output.avi.md5.
               ffmpeg -i input.flv -f avi -y md5:output.avi.md5

               # Write the MD5 hash of the encoded AVI file to stdout.
               ffmpeg -i input.flv -f avi -y md5:

       Note that some formats (typically MOV) require the output protocol to be seekable, so they will fail with the MD5 output
       protocol.

   pipe
       UNIX pipe access protocol.

       Read and write from UNIX pipes.

       The accepted syntax is:

               pipe:[<number>]

       number is the number corresponding to the file descriptor of the pipe (e.g. 0 for stdin, 1 for stdout, 2 for stderr).  If
       number is not specified, by default the stdout file descriptor will be used for writing, stdin for reading.

       For example to read from stdin with ffmpeg:

               cat test.wav | ffmpeg -i pipe:0
               # ...this is the same as...
               cat test.wav | ffmpeg -i pipe:

       For writing to stdout with ffmpeg:

               ffmpeg -i test.wav -f avi pipe:1 | cat > test.avi
               # ...this is the same as...
               ffmpeg -i test.wav -f avi pipe: | cat > test.avi

       This protocol accepts the following options:

       blocksize
           Set I/O operation maximum block size, in bytes. Default value is "INT_MAX", which results in not limiting the requested
           block size.  Setting this value reasonably low improves user termination request reaction time, which is valuable if
           data transmission is slow.

       Note that some formats (typically MOV), require the output protocol to be seekable, so they will fail with the pipe output
       protocol.

   prompeg
       Pro-MPEG Code of Practice #3 Release 2 FEC protocol.

       The Pro-MPEG CoP#3 FEC is a 2D parity-check forward error correction mechanism for MPEG-2 Transport Streams sent over RTP.

       This protocol must be used in conjunction with the "rtp_mpegts" muxer and the "rtp" protocol.

       The required syntax is:

               -f rtp_mpegts -fec prompeg=<option>=<val>... rtp://<hostname>:<port>

       The destination UDP ports are "port + 2" for the column FEC stream and "port + 4" for the row FEC stream.

       This protocol accepts the following options:

       l=n The number of columns (4-20, LxD <= 100)

       d=n The number of rows (4-20, LxD <= 100)

       Example usage:

               -f rtp_mpegts -fec prompeg=l=8:d=4 rtp://<hostname>:<port>

   rist
       Reliable Internet Streaming Transport protocol

       The accepted options are:

       rist_profile
           Supported values:

           simple
           main
               This one is default.

           advanced
       buffer_size
           Set internal RIST buffer size in milliseconds for retransmission of data.  Default value is 0 which means the librist
           default (1 sec). Maximum value is 30 seconds.

       fifo_size
           Size of the librist receiver output fifo in number of packets. This must be a power of 2.  Defaults to 8192 (vs the
           librist default of 1024).

       overrun_nonfatal=1|0
           Survive in case of librist fifo buffer overrun. Default value is 0.

       pkt_size
           Set maximum packet size for sending data. 1316 by default.

       log_level
           Set loglevel for RIST logging messages. You only need to set this if you explicitly want to enable debug level messages
           or packet loss simulation, otherwise the regular loglevel is respected.

       secret
           Set override of encryption secret, by default is unset.

       encryption
           Set encryption type, by default is disabled.  Acceptable values are 128 and 256.

   rtmp
       Real-Time Messaging Protocol.

       The Real-Time Messaging Protocol (RTMP) is used for streaming multimedia content across a TCP/IP network.

       The required syntax is:

               rtmp://[<username>:<password>@]<server>[:<port>][/<app>][/<instance>][/<playpath>]

       The accepted parameters are:

       username
           An optional username (mostly for publishing).

       password
           An optional password (mostly for publishing).

       server
           The address of the RTMP server.

       port
           The number of the TCP port to use (by default is 1935).

       app It is the name of the application to access. It usually corresponds to the path where the application is installed on
           the RTMP server (e.g. /ondemand/, /flash/live/, etc.). You can override the value parsed from the URI through the
           "rtmp_app" option, too.

       playpath
           It is the path or name of the resource to play with reference to the application specified in app, may be prefixed by
           "mp4:". You can override the value parsed from the URI through the "rtmp_playpath" option, too.

       listen
           Act as a server, listening for an incoming connection.

       timeout
           Maximum time to wait for the incoming connection. Implies listen.

       Additionally, the following parameters can be set via command line options (or in code via "AVOption"s):

       rtmp_app
           Name of application to connect on the RTMP server. This option overrides the parameter specified in the URI.

       rtmp_buffer
           Set the client buffer time in milliseconds. The default is 3000.

       rtmp_conn
           Extra arbitrary AMF connection parameters, parsed from a string, e.g. like "B:1 S:authMe O:1 NN:code:1.23 NS:flag:ok
           O:0".  Each value is prefixed by a single character denoting the type, B for Boolean, N for number, S for string, O for
           object, or Z for null, followed by a colon. For Booleans the data must be either 0 or 1 for FALSE or TRUE, respectively.
           Likewise for Objects the data must be 0 or 1 to end or begin an object, respectively. Data items in subobjects may be
           named, by prefixing the type with 'N' and specifying the name before the value (i.e. "NB:myFlag:1"). This option may be
           used multiple times to construct arbitrary AMF sequences.

       rtmp_flashver
           Version of the Flash plugin used to run the SWF player. The default is LNX 9,0,124,2. (When publishing, the default is
           FMLE/3.0 (compatible; <libavformat version>).)

       rtmp_flush_interval
           Number of packets flushed in the same request (RTMPT only). The default is 10.

       rtmp_live
           Specify that the media is a live stream. No resuming or seeking in live streams is possible. The default value is "any",
           which means the subscriber first tries to play the live stream specified in the playpath. If a live stream of that name
           is not found, it plays the recorded stream. The other possible values are "live" and "recorded".

       rtmp_pageurl
           URL of the web page in which the media was embedded. By default no value will be sent.

       rtmp_playpath
           Stream identifier to play or to publish. This option overrides the parameter specified in the URI.

       rtmp_subscribe
           Name of live stream to subscribe to. By default no value will be sent.  It is only sent if the option is specified or if
           rtmp_live is set to live.

       rtmp_swfhash
           SHA256 hash of the decompressed SWF file (32 bytes).

       rtmp_swfsize
           Size of the decompressed SWF file, required for SWFVerification.

       rtmp_swfurl
           URL of the SWF player for the media. By default no value will be sent.

       rtmp_swfverify
           URL to player swf file, compute hash/size automatically.

       rtmp_tcurl
           URL of the target stream. Defaults to proto://host[:port]/app.

       tcp_nodelay=1|0
           Set TCP_NODELAY to disable Nagle's algorithm. Default value is 0.

           Remark: Writing to the socket is currently not optimized to minimize system calls and reduces the efficiency / effect of
           TCP_NODELAY.

       For example to read with ffplay a multimedia resource named "sample" from the application "vod" from an RTMP server
       "myserver":

               ffplay rtmp://myserver/vod/sample

       To publish to a password protected server, passing the playpath and app names separately:

               ffmpeg -re -i <input> -f flv -rtmp_playpath some/long/path -rtmp_app long/app/name rtmp://username:password@myserver/

   rtmpe
       Encrypted Real-Time Messaging Protocol.

       The Encrypted Real-Time Messaging Protocol (RTMPE) is used for streaming multimedia content within standard cryptographic
       primitives, consisting of Diffie-Hellman key exchange and HMACSHA256, generating a pair of RC4 keys.

   rtmps
       Real-Time Messaging Protocol over a secure SSL connection.

       The Real-Time Messaging Protocol (RTMPS) is used for streaming multimedia content across an encrypted connection.

   rtmpt
       Real-Time Messaging Protocol tunneled through HTTP.

       The Real-Time Messaging Protocol tunneled through HTTP (RTMPT) is used for streaming multimedia content within HTTP requests
       to traverse firewalls.

   rtmpte
       Encrypted Real-Time Messaging Protocol tunneled through HTTP.

       The Encrypted Real-Time Messaging Protocol tunneled through HTTP (RTMPTE) is used for streaming multimedia content within
       HTTP requests to traverse firewalls.

   rtmpts
       Real-Time Messaging Protocol tunneled through HTTPS.

       The Real-Time Messaging Protocol tunneled through HTTPS (RTMPTS) is used for streaming multimedia content within HTTPS
       requests to traverse firewalls.

   libsmbclient
       libsmbclient permits one to manipulate CIFS/SMB network resources.

       Following syntax is required.

               smb://[[domain:]user[:password@]]server[/share[/path[/file]]]

       This protocol accepts the following options.

       timeout
           Set timeout in milliseconds of socket I/O operations used by the underlying low level operation. By default it is set to
           -1, which means that the timeout is not specified.

       truncate
           Truncate existing files on write, if set to 1. A value of 0 prevents truncating. Default value is 1.

       workgroup
           Set the workgroup used for making connections. By default workgroup is not specified.

       For more information see: <http://www.samba.org/>.

   libssh
       Secure File Transfer Protocol via libssh

       Read from or write to remote resources using SFTP protocol.

       Following syntax is required.

               sftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg

       This protocol accepts the following options.

       timeout
           Set timeout of socket I/O operations used by the underlying low level operation. By default it is set to -1, which means
           that the timeout is not specified.

       truncate
           Truncate existing files on write, if set to 1. A value of 0 prevents truncating. Default value is 1.

       private_key
           Specify the path of the file containing private key to use during authorization.  By default libssh searches for keys in
           the ~/.ssh/ directory.

       Example: Play a file stored on remote server.

               ffplay sftp://user:password@server_address:22/home/user/resource.mpeg

   librtmp rtmp, rtmpe, rtmps, rtmpt, rtmpte
       Real-Time Messaging Protocol and its variants supported through librtmp.

       Requires the presence of the librtmp headers and library during configuration. You need to explicitly configure the build
       with "--enable-librtmp". If enabled this will replace the native RTMP protocol.

       This protocol provides most client functions and a few server functions needed to support RTMP, RTMP tunneled in HTTP
       (RTMPT), encrypted RTMP (RTMPE), RTMP over SSL/TLS (RTMPS) and tunneled variants of these encrypted types (RTMPTE, RTMPTS).

       The required syntax is:

               <rtmp_proto>://<server>[:<port>][/<app>][/<playpath>] <options>

       where rtmp_proto is one of the strings "rtmp", "rtmpt", "rtmpe", "rtmps", "rtmpte", "rtmpts" corresponding to each RTMP
       variant, and server, port, app and playpath have the same meaning as specified for the RTMP native protocol.  options
       contains a list of space-separated options of the form key=val.

       See the librtmp manual page (man 3 librtmp) for more information.

       For example, to stream a file in real-time to an RTMP server using ffmpeg:

               ffmpeg -re -i myfile -f flv rtmp://myserver/live/mystream

       To play the same stream using ffplay:

               ffplay "rtmp://myserver/live/mystream live=1"

   rtp
       Real-time Transport Protocol.

       The required syntax for an RTP URL is: rtp://hostname[:port][?option=val...]

       port specifies the RTP port to use.

       The following URL options are supported:

       ttl=n
           Set the TTL (Time-To-Live) value (for multicast only).

       rtcpport=n
           Set the remote RTCP port to n.

       localrtpport=n
           Set the local RTP port to n.

       localrtcpport=n'
           Set the local RTCP port to n.

       pkt_size=n
           Set max packet size (in bytes) to n.

       buffer_size=size
           Set the maximum UDP socket buffer size in bytes.

       connect=0|1
           Do a "connect()" on the UDP socket (if set to 1) or not (if set to 0).

       sources=ip[,ip]
           List allowed source IP addresses.

       block=ip[,ip]
           List disallowed (blocked) source IP addresses.

       write_to_source=0|1
           Send packets to the source address of the latest received packet (if set to 1) or to a default remote address (if set to
           0).

       localport=n
           Set the local RTP port to n.

       localaddr=addr
           Local IP address of a network interface used for sending packets or joining multicast groups.

       timeout=n
           Set timeout (in microseconds) of socket I/O operations to n.

           This is a deprecated option. Instead, localrtpport should be used.

       Important notes:

       1.  If rtcpport is not set the RTCP port will be set to the RTP port value plus 1.

       2.  If localrtpport (the local RTP port) is not set any available port will be used for the local RTP and RTCP ports.

       3.  If localrtcpport (the local RTCP port) is not set it will be set to the local RTP port value plus 1.

   rtsp
       Real-Time Streaming Protocol.

       RTSP is not technically a protocol handler in libavformat, it is a demuxer and muxer. The demuxer supports both normal RTSP
       (with data transferred over RTP; this is used by e.g. Apple and Microsoft) and Real-RTSP (with data transferred over RDT).

       The muxer can be used to send a stream using RTSP ANNOUNCE to a server supporting it (currently Darwin Streaming Server and
       Mischa Spiegelmock's <https://github.com/revmischa/rtsp-server>).

       The required syntax for a RTSP url is:

               rtsp://<hostname>[:<port>]/<path>

       Options can be set on the ffmpeg/ffplay command line, or set in code via "AVOption"s or in "avformat_open_input".

       The following options are supported.

       initial_pause
           Do not start playing the stream immediately if set to 1. Default value is 0.

       rtsp_transport
           Set RTSP transport protocols.

           It accepts the following values:

           udp Use UDP as lower transport protocol.

           tcp Use TCP (interleaving within the RTSP control channel) as lower transport protocol.

           udp_multicast
               Use UDP multicast as lower transport protocol.

           http
               Use HTTP tunneling as lower transport protocol, which is useful for passing proxies.

           Multiple lower transport protocols may be specified, in that case they are tried one at a time (if the setup of one
           fails, the next one is tried).  For the muxer, only the tcp and udp options are supported.

       rtsp_flags
           Set RTSP flags.

           The following values are accepted:

           filter_src
               Accept packets only from negotiated peer address and port.

           listen
               Act as a server, listening for an incoming connection.

           prefer_tcp
               Try TCP for RTP transport first, if TCP is available as RTSP RTP transport.

           Default value is none.

       allowed_media_types
           Set media types to accept from the server.

           The following flags are accepted:

           video
           audio
           data

           By default it accepts all media types.

       min_port
           Set minimum local UDP port. Default value is 5000.

       max_port
           Set maximum local UDP port. Default value is 65000.

       listen_timeout
           Set maximum timeout (in seconds) to establish an initial connection. Setting listen_timeout > 0 sets rtsp_flags to
           listen. Default is -1 which means an infinite timeout when listen mode is set.

       reorder_queue_size
           Set number of packets to buffer for handling of reordered packets.

       timeout
           Set socket TCP I/O timeout in microseconds.

       user_agent
           Override User-Agent header. If not specified, it defaults to the libavformat identifier string.

       When receiving data over UDP, the demuxer tries to reorder received packets (since they may arrive out of order, or packets
       may get lost totally). This can be disabled by setting the maximum demuxing delay to zero (via the "max_delay" field of
       AVFormatContext).

       When watching multi-bitrate Real-RTSP streams with ffplay, the streams to display can be chosen with "-vst" n and "-ast" n
       for video and audio respectively, and can be switched on the fly by pressing "v" and "a".

       Examples

       The following examples all make use of the ffplay and ffmpeg tools.

       •   Watch a stream over UDP, with a max reordering delay of 0.5 seconds:

                   ffplay -max_delay 500000 -rtsp_transport udp rtsp://server/video.mp4

       •   Watch a stream tunneled over HTTP:

                   ffplay -rtsp_transport http rtsp://server/video.mp4

       •   Send a stream in realtime to a RTSP server, for others to watch:

                   ffmpeg -re -i <input> -f rtsp -muxdelay 0.1 rtsp://server/live.sdp

       •   Receive a stream in realtime:

                   ffmpeg -rtsp_flags listen -i rtsp://ownaddress/live.sdp <output>

   sap
       Session Announcement Protocol (RFC 2974). This is not technically a protocol handler in libavformat, it is a muxer and
       demuxer.  It is used for signalling of RTP streams, by announcing the SDP for the streams regularly on a separate port.

       Muxer

       The syntax for a SAP url given to the muxer is:

               sap://<destination>[:<port>][?<options>]

       The RTP packets are sent to destination on port port, or to port 5004 if no port is specified.  options is a "&"-separated
       list. The following options are supported:

       announce_addr=address
           Specify the destination IP address for sending the announcements to.  If omitted, the announcements are sent to the
           commonly used SAP announcement multicast address 224.2.127.254 (sap.mcast.net), or ff0e::2:7ffe if destination is an
           IPv6 address.

       announce_port=port
           Specify the port to send the announcements on, defaults to 9875 if not specified.

       ttl=ttl
           Specify the time to live value for the announcements and RTP packets, defaults to 255.

       same_port=0|1
           If set to 1, send all RTP streams on the same port pair. If zero (the default), all streams are sent on unique ports,
           with each stream on a port 2 numbers higher than the previous.  VLC/Live555 requires this to be set to 1, to be able to
           receive the stream.  The RTP stack in libavformat for receiving requires all streams to be sent on unique ports.

       Example command lines follow.

       To broadcast a stream on the local subnet, for watching in VLC:

               ffmpeg -re -i <input> -f sap sap://224.0.0.255?same_port=1

       Similarly, for watching in ffplay:

               ffmpeg -re -i <input> -f sap sap://224.0.0.255

       And for watching in ffplay, over IPv6:

               ffmpeg -re -i <input> -f sap sap://[ff0e::1:2:3:4]

       Demuxer

       The syntax for a SAP url given to the demuxer is:

               sap://[<address>][:<port>]

       address is the multicast address to listen for announcements on, if omitted, the default 224.2.127.254 (sap.mcast.net) is
       used. port is the port that is listened on, 9875 if omitted.

       The demuxers listens for announcements on the given address and port.  Once an announcement is received, it tries to receive
       that particular stream.

       Example command lines follow.

       To play back the first stream announced on the normal SAP multicast address:

               ffplay sap://

       To play back the first stream announced on one the default IPv6 SAP multicast address:

               ffplay sap://[ff0e::2:7ffe]

   sctp
       Stream Control Transmission Protocol.

       The accepted URL syntax is:

               sctp://<host>:<port>[?<options>]

       The protocol accepts the following options:

       listen
           If set to any value, listen for an incoming connection. Outgoing connection is done by default.

       max_streams
           Set the maximum number of streams. By default no limit is set.

   srt
       Haivision Secure Reliable Transport Protocol via libsrt.

       The supported syntax for a SRT URL is:

               srt://<hostname>:<port>[?<options>]

       options contains a list of &-separated options of the form key=val.

       or

               <options> srt://<hostname>:<port>

       options contains a list of '-key val' options.

       This protocol accepts the following options.

       connect_timeout=milliseconds
           Connection timeout; SRT cannot connect for RTT > 1500 msec (2 handshake exchanges) with the default connect timeout of 3
           seconds. This option applies to the caller and rendezvous connection modes. The connect timeout is 10 times the value
           set for the rendezvous mode (which can be used as a workaround for this connection problem with earlier versions).

       ffs=bytes
           Flight Flag Size (Window Size), in bytes. FFS is actually an internal parameter and you should set it to not less than
           recv_buffer_size and mss. The default value is relatively large, therefore unless you set a very large receiver buffer,
           you do not need to change this option. Default value is 25600.

       inputbw=bytes/seconds
           Sender nominal input rate, in bytes per seconds. Used along with oheadbw, when maxbw is set to relative (0), to
           calculate maximum sending rate when recovery packets are sent along with the main media stream: inputbw * (100 +
           oheadbw) / 100 if inputbw is not set while maxbw is set to relative (0), the actual input rate is evaluated inside the
           library. Default value is 0.

       iptos=tos
           IP Type of Service. Applies to sender only. Default value is 0xB8.

       ipttl=ttl
           IP Time To Live. Applies to sender only. Default value is 64.

       latency=microseconds
           Timestamp-based Packet Delivery Delay.  Used to absorb bursts of missed packet retransmissions.  This flag sets both
           rcvlatency and peerlatency to the same value. Note that prior to version 1.3.0 this is the only flag to set the latency,
           however this is effectively equivalent to setting peerlatency, when side is sender and rcvlatency when side is receiver,
           and the bidirectional stream sending is not supported.

       listen_timeout=microseconds
           Set socket listen timeout.

       maxbw=bytes/seconds
           Maximum sending bandwidth, in bytes per seconds.  -1 infinite (CSRTCC limit is 30mbps) 0 relative to input rate (see
           inputbw) >0 absolute limit value Default value is 0 (relative)

       mode=caller|listener|rendezvous
           Connection mode.  caller opens client connection.  listener starts server to listen for incoming connections.
           rendezvous use Rendez-Vous connection mode.  Default value is caller.

       mss=bytes
           Maximum Segment Size, in bytes. Used for buffer allocation and rate calculation using a packet counter assuming fully
           filled packets. The smallest MSS between the peers is used. This is 1500 by default in the overall internet.  This is
           the maximum size of the UDP packet and can be only decreased, unless you have some unusual dedicated network settings.
           Default value is 1500.

       nakreport=1|0
           If set to 1, Receiver will send `UMSG_LOSSREPORT` messages periodically until a lost packet is retransmitted or
           intentionally dropped. Default value is 1.

       oheadbw=percents
           Recovery bandwidth overhead above input rate, in percents.  See inputbw. Default value is 25%.

       passphrase=string
           HaiCrypt Encryption/Decryption Passphrase string, length from 10 to 79 characters. The passphrase is the shared secret
           between the sender and the receiver. It is used to generate the Key Encrypting Key using PBKDF2 (Password-Based Key
           Derivation Function). It is used only if pbkeylen is non-zero. It is used on the receiver only if the received data is
           encrypted.  The configured passphrase cannot be recovered (write-only).

       enforced_encryption=1|0
           If true, both connection parties must have the same password set (including empty, that is, with no encryption). If the
           password doesn't match or only one side is unencrypted, the connection is rejected. Default is true.

       kmrefreshrate=packets
           The number of packets to be transmitted after which the encryption key is switched to a new key. Default is -1.  -1
           means auto (0x1000000 in srt library). The range for this option is integers in the 0 - "INT_MAX".

       kmpreannounce=packets
           The interval between when a new encryption key is sent and when switchover occurs. This value also applies to the
           subsequent interval between when switchover occurs and when the old encryption key is decommissioned. Default is -1.  -1
           means auto (0x1000 in srt library). The range for this option is integers in the 0 - "INT_MAX".

       snddropdelay=microseconds
           The sender's extra delay before dropping packets. This delay is added to the default drop delay time interval value.

           Special value -1: Do not drop packets on the sender at all.

       payload_size=bytes
           Sets the maximum declared size of a packet transferred during the single call to the sending function in Live mode. Use
           0 if this value isn't used (which is default in file mode).  Default is -1 (automatic), which typically means MPEG-TS;
           if you are going to use SRT to send any different kind of payload, such as, for example, wrapping a live stream in very
           small frames, then you can use a bigger maximum frame size, though not greater than 1456 bytes.

       pkt_size=bytes
           Alias for payload_size.

       peerlatency=microseconds
           The latency value (as described in rcvlatency) that is set by the sender side as a minimum value for the receiver.

       pbkeylen=bytes
           Sender encryption key length, in bytes.  Only can be set to 0, 16, 24 and 32.  Enable sender encryption if not 0.  Not
           required on receiver (set to 0), key size obtained from sender in HaiCrypt handshake.  Default value is 0.

       rcvlatency=microseconds
           The time that should elapse since the moment when the packet was sent and the moment when it's delivered to the receiver
           application in the receiving function.  This time should be a buffer time large enough to cover the time spent for
           sending, unexpectedly extended RTT time, and the time needed to retransmit the lost UDP packet. The effective latency
           value will be the maximum of this options' value and the value of peerlatency set by the peer side. Before version 1.3.0
           this option is only available as latency.

       recv_buffer_size=bytes
           Set UDP receive buffer size, expressed in bytes.

       send_buffer_size=bytes
           Set UDP send buffer size, expressed in bytes.

       timeout=microseconds
           Set raise error timeouts for read, write and connect operations. Note that the SRT library has internal timeouts which
           can be controlled separately, the value set here is only a cap on those.

       tlpktdrop=1|0
           Too-late Packet Drop. When enabled on receiver, it skips missing packets that have not been delivered in time and
           delivers the following packets to the application when their time-to-play has come. It also sends a fake ACK to the
           sender. When enabled on sender and enabled on the receiving peer, the sender drops the older packets that have no chance
           of being delivered in time. It was automatically enabled in the sender if the receiver supports it.

       sndbuf=bytes
           Set send buffer size, expressed in bytes.

       rcvbuf=bytes
           Set receive buffer size, expressed in bytes.

           Receive buffer must not be greater than ffs.

       lossmaxttl=packets
           The value up to which the Reorder Tolerance may grow. When Reorder Tolerance is > 0, then packet loss report is delayed
           until that number of packets come in. Reorder Tolerance increases every time a "belated" packet has come, but it wasn't
           due to retransmission (that is, when UDP packets tend to come out of order), with the difference between the latest
           sequence and this packet's sequence, and not more than the value of this option. By default it's 0, which means that
           this mechanism is turned off, and the loss report is always sent immediately upon experiencing a "gap" in sequences.

       minversion
           The minimum SRT version that is required from the peer. A connection to a peer that does not satisfy the minimum version
           requirement will be rejected.

           The version format in hex is 0xXXYYZZ for x.y.z in human readable form.

       streamid=string
           A string limited to 512 characters that can be set on the socket prior to connecting. This stream ID will be able to be
           retrieved by the listener side from the socket that is returned from srt_accept and was connected by a socket with that
           set stream ID. SRT does not enforce any special interpretation of the contents of this string.  This option doesnXt make
           sense in Rendezvous connection; the result might be that simply one side will override the value from the other side and
           itXs the matter of luck which one would win

       srt_streamid=string
           Alias for streamid to avoid conflict with ffmpeg command line option.

       smoother=live|file
           The type of Smoother used for the transmission for that socket, which is responsible for the transmission and congestion
           control. The Smoother type must be exactly the same on both connecting parties, otherwise the connection is rejected.

       messageapi=1|0
           When set, this socket uses the Message API, otherwise it uses Buffer API. Note that in live mode (see transtype) thereXs
           only message API available. In File mode you can chose to use one of two modes:

           Stream API (default, when this option is false). In this mode you may send as many data as you wish with one sending
           instruction, or even use dedicated functions that read directly from a file. The internal facility will take care of any
           speed and congestion control. When receiving, you can also receive as many data as desired, the data not extracted will
           be waiting for the next call. There is no boundary between data portions in the Stream mode.

           Message API. In this mode your single sending instruction passes exactly one piece of data that has boundaries (a
           message). Contrary to Live mode, this message may span across multiple UDP packets and the only size limitation is that
           it shall fit as a whole in the sending buffer. The receiver shall use as large buffer as necessary to receive the
           message, otherwise the message will not be given up. When the message is not complete (not all packets received or there
           was a packet loss) it will not be given up.

       transtype=live|file
           Sets the transmission type for the socket, in particular, setting this option sets multiple other parameters to their
           default values as required for a particular transmission type.

           live: Set options as for live transmission. In this mode, you should send by one sending instruction only so many data
           that fit in one UDP packet, and limited to the value defined first in payload_size (1316 is default in this mode). There
           is no speed control in this mode, only the bandwidth control, if configured, in order to not exceed the bandwidth with
           the overhead transmission (retransmitted and control packets).

           file: Set options as for non-live transmission. See messageapi for further explanations

       linger=seconds
           The number of seconds that the socket waits for unsent data when closing.  Default is -1. -1 means auto (off with 0
           seconds in live mode, on with 180 seconds in file mode). The range for this option is integers in the 0 - "INT_MAX".

       tsbpd=1|0
           When true, use Timestamp-based Packet Delivery mode. The default behavior depends on the transmission type: enabled in
           live mode, disabled in file mode.

       For more information see: <https://github.com/Haivision/srt>.

   srtp
       Secure Real-time Transport Protocol.

       The accepted options are:

       srtp_in_suite
       srtp_out_suite
           Select input and output encoding suites.

           Supported values:

           AES_CM_128_HMAC_SHA1_80
           SRTP_AES128_CM_HMAC_SHA1_80
           AES_CM_128_HMAC_SHA1_32
           SRTP_AES128_CM_HMAC_SHA1_32
       srtp_in_params
       srtp_out_params
           Set input and output encoding parameters, which are expressed by a base64-encoded representation of a binary block. The
           first 16 bytes of this binary block are used as master key, the following 14 bytes are used as master salt.

   subfile
       Virtually extract a segment of a file or another stream.  The underlying stream must be seekable.

       Accepted options:

       start
           Start offset of the extracted segment, in bytes.

       end End offset of the extracted segment, in bytes.  If set to 0, extract till end of file.

       Examples:

       Extract a chapter from a DVD VOB file (start and end sectors obtained externally and multiplied by 2048):

               subfile,,start,153391104,end,268142592,,:/media/dvd/VIDEO_TS/VTS_08_1.VOB

       Play an AVI file directly from a TAR archive:

               subfile,,start,183241728,end,366490624,,:archive.tar

       Play a MPEG-TS file from start offset till end:

               subfile,,start,32815239,end,0,,:video.ts

   tee
       Writes the output to multiple protocols. The individual outputs are separated by |

               tee:file://path/to/local/this.avi|file://path/to/local/that.avi

   tcp
       Transmission Control Protocol.

       The required syntax for a TCP url is:

               tcp://<hostname>:<port>[?<options>]

       options contains a list of &-separated options of the form key=val.

       The list of supported options follows.

       listen=2|1|0
           Listen for an incoming connection. 0 disables listen, 1 enables listen in single client mode, 2 enables listen in multi-
           client mode. Default value is 0.

       timeout=microseconds
           Set raise error timeout, expressed in microseconds.

           This option is only relevant in read mode: if no data arrived in more than this time interval, raise error.

       listen_timeout=milliseconds
           Set listen timeout, expressed in milliseconds.

       recv_buffer_size=bytes
           Set receive buffer size, expressed bytes.

       send_buffer_size=bytes
           Set send buffer size, expressed bytes.

       tcp_nodelay=1|0
           Set TCP_NODELAY to disable Nagle's algorithm. Default value is 0.

           Remark: Writing to the socket is currently not optimized to minimize system calls and reduces the efficiency / effect of
           TCP_NODELAY.

       tcp_mss=bytes
           Set maximum segment size for outgoing TCP packets, expressed in bytes.

       The following example shows how to setup a listening TCP connection with ffmpeg, which is then accessed with ffplay:

               ffmpeg -i <input> -f <format> tcp://<hostname>:<port>?listen
               ffplay tcp://<hostname>:<port>

   tls
       Transport Layer Security (TLS) / Secure Sockets Layer (SSL)

       The required syntax for a TLS/SSL url is:

               tls://<hostname>:<port>[?<options>]

       The following parameters can be set via command line options (or in code via "AVOption"s):

       ca_file, cafile=filename
           A file containing certificate authority (CA) root certificates to treat as trusted. If the linked TLS library contains a
           default this might not need to be specified for verification to work, but not all libraries and setups have defaults
           built in.  The file must be in OpenSSL PEM format.

       tls_verify=1|0
           If enabled, try to verify the peer that we are communicating with.  Note, if using OpenSSL, this currently only makes
           sure that the peer certificate is signed by one of the root certificates in the CA database, but it does not validate
           that the certificate actually matches the host name we are trying to connect to. (With other backends, the host name is
           validated as well.)

           This is disabled by default since it requires a CA database to be provided by the caller in many cases.

       cert_file, cert=filename
           A file containing a certificate to use in the handshake with the peer.  (When operating as server, in listen mode, this
           is more often required by the peer, while client certificates only are mandated in certain setups.)

       key_file, key=filename
           A file containing the private key for the certificate.

       listen=1|0
           If enabled, listen for connections on the provided port, and assume the server role in the handshake instead of the
           client role.

       http_proxy
           The HTTP proxy to tunnel through, e.g. "http://example.com:1234".  The proxy must support the CONNECT method.

       Example command lines:

       To create a TLS/SSL server that serves an input stream.

               ffmpeg -i <input> -f <format> tls://<hostname>:<port>?listen&cert=<server.crt>&key=<server.key>

       To play back a stream from the TLS/SSL server using ffplay:

               ffplay tls://<hostname>:<port>

   udp
       User Datagram Protocol.

       The required syntax for an UDP URL is:

               udp://<hostname>:<port>[?<options>]

       options contains a list of &-separated options of the form key=val.

       In case threading is enabled on the system, a circular buffer is used to store the incoming data, which allows one to reduce
       loss of data due to UDP socket buffer overruns. The fifo_size and overrun_nonfatal options are related to this buffer.

       The list of supported options follows.

       buffer_size=size
           Set the UDP maximum socket buffer size in bytes. This is used to set either the receive or send buffer size, depending
           on what the socket is used for.  Default is 32 KB for output, 384 KB for input.  See also fifo_size.

       bitrate=bitrate
           If set to nonzero, the output will have the specified constant bitrate if the input has enough packets to sustain it.

       burst_bits=bits
           When using bitrate this specifies the maximum number of bits in packet bursts.

       localport=port
           Override the local UDP port to bind with.

       localaddr=addr
           Local IP address of a network interface used for sending packets or joining multicast groups.

       pkt_size=size
           Set the size in bytes of UDP packets.

       reuse=1|0
           Explicitly allow or disallow reusing UDP sockets.

       ttl=ttl
           Set the time to live value (for multicast only).

       connect=1|0
           Initialize the UDP socket with "connect()". In this case, the destination address can't be changed with
           ff_udp_set_remote_url later.  If the destination address isn't known at the start, this option can be specified in
           ff_udp_set_remote_url, too.  This allows finding out the source address for the packets with getsockname, and makes
           writes return with AVERROR(ECONNREFUSED) if "destination unreachable" is received.  For receiving, this gives the
           benefit of only receiving packets from the specified peer address/port.

       sources=address[,address]
           Only receive packets sent from the specified addresses. In case of multicast, also subscribe to multicast traffic coming
           from these addresses only.

       block=address[,address]
           Ignore packets sent from the specified addresses. In case of multicast, also exclude the source addresses in the
           multicast subscription.

       fifo_size=units
           Set the UDP receiving circular buffer size, expressed as a number of packets with size of 188 bytes. If not specified
           defaults to 7*4096.

       overrun_nonfatal=1|0
           Survive in case of UDP receiving circular buffer overrun. Default value is 0.

       timeout=microseconds
           Set raise error timeout, expressed in microseconds.

           This option is only relevant in read mode: if no data arrived in more than this time interval, raise error.

       broadcast=1|0
           Explicitly allow or disallow UDP broadcasting.

           Note that broadcasting may not work properly on networks having a broadcast storm protection.

       Examples

       •   Use ffmpeg to stream over UDP to a remote endpoint:

                   ffmpeg -i <input> -f <format> udp://<hostname>:<port>

       •   Use ffmpeg to stream in mpegts format over UDP using 188 sized UDP packets, using a large input buffer:

                   ffmpeg -i <input> -f mpegts udp://<hostname>:<port>?pkt_size=188&buffer_size=65535

       •   Use ffmpeg to receive over UDP from a remote endpoint:

                   ffmpeg -i udp://[<multicast-address>]:<port> ...

   unix
       Unix local socket

       The required syntax for a Unix socket URL is:

               unix://<filepath>

       The following parameters can be set via command line options (or in code via "AVOption"s):

       timeout
           Timeout in ms.

       listen
           Create the Unix socket in listening mode.

   zmq
       ZeroMQ asynchronous messaging using the libzmq library.

       This library supports unicast streaming to multiple clients without relying on an external server.

       The required syntax for streaming or connecting to a stream is:

               zmq:tcp://ip-address:port

       Example: Create a localhost stream on port 5555:

               ffmpeg -re -i input -f mpegts zmq:tcp://127.0.0.1:5555

       Multiple clients may connect to the stream using:

               ffplay zmq:tcp://127.0.0.1:5555

       Streaming to multiple clients is implemented using a ZeroMQ Pub-Sub pattern.  The server side binds to a port and publishes
       data. Clients connect to the server (via IP address/port) and subscribe to the stream. The order in which the server and
       client start generally does not matter.

       ffmpeg must be compiled with the --enable-libzmq option to support this protocol.

       Options can be set on the ffmpeg/ffplay command line. The following options are supported:

       pkt_size
           Forces the maximum packet size for sending/receiving data. The default value is 131,072 bytes. On the server side, this
           sets the maximum size of sent packets via ZeroMQ. On the clients, it sets an internal buffer size for receiving packets.
           Note that pkt_size on the clients should be equal to or greater than pkt_size on the server. Otherwise the received
           message may be truncated causing decoding errors.

DEVICE OPTIONS
       The libavdevice library provides the same interface as libavformat. Namely, an input device is considered like a demuxer,
       and an output device like a muxer, and the interface and generic device options are the same provided by libavformat (see
       the ffmpeg-formats manual).

       In addition each input or output device may support so-called private options, which are specific for that component.

       Options may be set by specifying -option value in the FFmpeg tools, or by setting the value explicitly in the device
       "AVFormatContext" options or using the libavutil/opt.h API for programmatic use.

INPUT DEVICES
       Input devices are configured elements in FFmpeg which enable accessing the data coming from a multimedia device attached to
       your system.

       When you configure your FFmpeg build, all the supported input devices are enabled by default. You can list all available
       ones using the configure option "--list-indevs".

       You can disable all the input devices using the configure option "--disable-indevs", and selectively enable an input device
       using the option "--enable-indev=INDEV", or you can disable a particular input device using the option
       "--disable-indev=INDEV".

       The option "-devices" of the ff* tools will display the list of supported input devices.

       A description of the currently available input devices follows.

   alsa
       ALSA (Advanced Linux Sound Architecture) input device.

       To enable this input device during configuration you need libasound installed on your system.

       This device allows capturing from an ALSA device. The name of the device to capture has to be an ALSA card identifier.

       An ALSA identifier has the syntax:

               hw:<CARD>[,<DEV>[,<SUBDEV>]]

       where the DEV and SUBDEV components are optional.

       The three arguments (in order: CARD,DEV,SUBDEV) specify card number or identifier, device number and subdevice number (-1
       means any).

       To see the list of cards currently recognized by your system check the files /proc/asound/cards and /proc/asound/devices.

       For example to capture with ffmpeg from an ALSA device with card id 0, you may run the command:

               ffmpeg -f alsa -i hw:0 alsaout.wav

       For more information see: <http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html>

       Options

       sample_rate
           Set the sample rate in Hz. Default is 48000.

       channels
           Set the number of channels. Default is 2.

   android_camera
       Android camera input device.

       This input devices uses the Android Camera2 NDK API which is available on devices with API level 24+. The availability of
       android_camera is autodetected during configuration.

       This device allows capturing from all cameras on an Android device, which are integrated into the Camera2 NDK API.

       The available cameras are enumerated internally and can be selected with the camera_index parameter. The input file string
       is discarded.

       Generally the back facing camera has index 0 while the front facing camera has index 1.

       Options

       video_size
           Set the video size given as a string such as 640x480 or hd720.  Falls back to the first available configuration reported
           by Android if requested video size is not available or by default.

       framerate
           Set the video framerate.  Falls back to the first available configuration reported by Android if requested framerate is
           not available or by default (-1).

       camera_index
           Set the index of the camera to use. Default is 0.

       input_queue_size
           Set the maximum number of frames to buffer. Default is 5.

   avfoundation
       AVFoundation input device.

       AVFoundation is the currently recommended framework by Apple for streamgrabbing on OSX >= 10.7 as well as on iOS.

       The input filename has to be given in the following syntax:

               -i "[[VIDEO]:[AUDIO]]"

       The first entry selects the video input while the latter selects the audio input.  The stream has to be specified by the
       device name or the device index as shown by the device list.  Alternatively, the video and/or audio input device can be
       chosen by index using the

           B<-video_device_index E<lt>INDEXE<gt>>

       and/or

           B<-audio_device_index E<lt>INDEXE<gt>>

       , overriding any device name or index given in the input filename.

       All available devices can be enumerated by using -list_devices true, listing all device names and corresponding indices.

       There are two device name aliases:

       "default"
           Select the AVFoundation default device of the corresponding type.

       "none"
           Do not record the corresponding media type.  This is equivalent to specifying an empty device name or index.

       Options

       AVFoundation supports the following options:

       -list_devices <TRUE|FALSE>
           If set to true, a list of all available input devices is given showing all device names and indices.

       -video_device_index <INDEX>
           Specify the video device by its index. Overrides anything given in the input filename.

       -audio_device_index <INDEX>
           Specify the audio device by its index. Overrides anything given in the input filename.

       -pixel_format <FORMAT>
           Request the video device to use a specific pixel format.  If the specified format is not supported, a list of available
           formats is given and the first one in this list is used instead. Available pixel formats are: "monob, rgb555be,
           rgb555le, rgb565be, rgb565le, rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0,
            bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, yuv422p10, yuv444p10,
            yuv420p, nv12, yuyv422, gray"

       -framerate
           Set the grabbing frame rate. Default is "ntsc", corresponding to a frame rate of "30000/1001".

       -video_size
           Set the video frame size.

       -capture_cursor
           Capture the mouse pointer. Default is 0.

       -capture_mouse_clicks
           Capture the screen mouse clicks. Default is 0.

       -capture_raw_data
           Capture the raw device data. Default is 0.  Using this option may result in receiving the underlying data delivered to
           the AVFoundation framework. E.g. for muxed devices that sends raw DV data to the framework (like tape-based camcorders),
           setting this option to false results in extracted video frames captured in the designated pixel format only. Setting
           this option to true results in receiving the raw DV stream untouched.

       Examples

       •   Print the list of AVFoundation supported devices and exit:

                   $ ffmpeg -f avfoundation -list_devices true -i ""

       •   Record video from video device 0 and audio from audio device 0 into out.avi:

                   $ ffmpeg -f avfoundation -i "0:0" out.avi

       •   Record video from video device 2 and audio from audio device 1 into out.avi:

                   $ ffmpeg -f avfoundation -video_device_index 2 -i ":1" out.avi

       •   Record video from the system default video device using the pixel format bgr0 and do not record any audio into out.avi:

                   $ ffmpeg -f avfoundation -pixel_format bgr0 -i "default:none" out.avi

       •   Record raw DV data from a suitable input device and write the output into out.dv:

                   $ ffmpeg -f avfoundation -capture_raw_data true -i "zr100:none" out.dv

   bktr
       BSD video input device.

       Options

       framerate
           Set the frame rate.

       video_size
           Set the video frame size. Default is "vga".

       standard
           Available values are:

           pal
           ntsc
           secam
           paln
           palm
           ntscj

   decklink
       The decklink input device provides capture capabilities for Blackmagic DeckLink devices.

       To enable this input device, you need the Blackmagic DeckLink SDK and you need to configure with the appropriate
       "--extra-cflags" and "--extra-ldflags".  On Windows, you need to run the IDL files through widl.

       DeckLink is very picky about the formats it supports. Pixel format of the input can be set with raw_format.  Framerate and
       video size must be determined for your device with -list_formats 1. Audio sample rate is always 48 kHz and the number of
       channels can be 2, 8 or 16. Note that all audio channels are bundled in one single audio track.

       Options

       list_devices
           If set to true, print a list of devices and exit.  Defaults to false. This option is deprecated, please use the
           "-sources" option of ffmpeg to list the available input devices.

       list_formats
           If set to true, print a list of supported formats and exit.  Defaults to false.

       format_code <FourCC>
           This sets the input video format to the format given by the FourCC. To see the supported values of your device(s) use
           list_formats.  Note that there is a FourCC 'pal ' that can also be used as pal (3 letters).  Default behavior is
           autodetection of the input video format, if the hardware supports it.

       raw_format
           Set the pixel format of the captured video.  Available values are:

           auto
               This is the default which means 8-bit YUV 422 or 8-bit ARGB if format autodetection is used, 8-bit YUV 422
               otherwise.

           uyvy422
               8-bit YUV 422.

           yuv422p10
               10-bit YUV 422.

           argb
               8-bit RGB.

           bgra
               8-bit RGB.

           rgb10
               10-bit RGB.

       teletext_lines
           If set to nonzero, an additional teletext stream will be captured from the vertical ancillary data. Both SD PAL (576i)
           and HD (1080i or 1080p) sources are supported. In case of HD sources, OP47 packets are decoded.

           This option is a bitmask of the SD PAL VBI lines captured, specifically lines 6 to 22, and lines 318 to 335. Line 6 is
           the LSB in the mask. Selected lines which do not contain teletext information will be ignored. You can use the special
           all constant to select all possible lines, or standard to skip lines 6, 318 and 319, which are not compatible with all
           receivers.

           For SD sources, ffmpeg needs to be compiled with "--enable-libzvbi". For HD sources, on older (pre-4K) DeckLink card
           models you have to capture in 10 bit mode.

       channels
           Defines number of audio channels to capture. Must be 2, 8 or 16.  Defaults to 2.

       duplex_mode
           Sets the decklink device duplex/profile mode. Must be unset, half, full, one_sub_device_full, one_sub_device_half,
           two_sub_device_full, four_sub_device_half Defaults to unset.

           Note: DeckLink SDK 11.0 have replaced the duplex property by a profile property.  For the DeckLink Duo 2 and DeckLink
           Quad 2, a profile is shared between any 2 sub-devices that utilize the same connectors. For the DeckLink 8K Pro, a
           profile is shared between all 4 sub-devices. So DeckLink 8K Pro support four profiles.

           Valid profile modes for DeckLink 8K Pro(with DeckLink SDK >= 11.0): one_sub_device_full, one_sub_device_half,
           two_sub_device_full, four_sub_device_half

           Valid profile modes for DeckLink Quad 2 and DeckLink Duo 2: half, full

       timecode_format
           Timecode type to include in the frame and video stream metadata. Must be none, rp188vitc, rp188vitc2, rp188ltc,
           rp188hfr, rp188any, vitc, vitc2, or serial.  Defaults to none (not included).

           In order to properly support 50/60 fps timecodes, the ordering of the queried timecode types for rp188any is HFR, VITC1,
           VITC2 and LTC for >30 fps content. Note that this is slightly different to the ordering used by the DeckLink API, which
           is HFR, VITC1, LTC, VITC2.

       video_input
           Sets the video input source. Must be unset, sdi, hdmi, optical_sdi, component, composite or s_video.  Defaults to unset.

       audio_input
           Sets the audio input source. Must be unset, embedded, aes_ebu, analog, analog_xlr, analog_rca or microphone. Defaults to
           unset.

       video_pts
           Sets the video packet timestamp source. Must be video, audio, reference, wallclock or abs_wallclock.  Defaults to video.

       audio_pts
           Sets the audio packet timestamp source. Must be video, audio, reference, wallclock or abs_wallclock.  Defaults to audio.

       draw_bars
           If set to true, color bars are drawn in the event of a signal loss.  Defaults to true.

       queue_size
           Sets maximum input buffer size in bytes. If the buffering reaches this value, incoming frames will be dropped.  Defaults
           to 1073741824.

       audio_depth
           Sets the audio sample bit depth. Must be 16 or 32.  Defaults to 16.

       decklink_copyts
           If set to true, timestamps are forwarded as they are without removing the initial offset.  Defaults to false.

       timestamp_align
           Capture start time alignment in seconds. If set to nonzero, input frames are dropped till the system timestamp aligns
           with configured value.  Alignment difference of up to one frame duration is tolerated.  This is useful for maintaining
           input synchronization across N different hardware devices deployed for 'N-way' redundancy. The system time of different
           hardware devices should be synchronized with protocols such as NTP or PTP, before using this option.  Note that this
           method is not foolproof. In some border cases input synchronization may not happen due to thread scheduling jitters in
           the OS.  Either sync could go wrong by 1 frame or in a rarer case timestamp_align seconds.  Defaults to 0.

       wait_for_tc (bool)
           Drop frames till a frame with timecode is received. Sometimes serial timecode isn't received with the first input frame.
           If that happens, the stored stream timecode will be inaccurate. If this option is set to true, input frames are dropped
           till a frame with timecode is received.  Option timecode_format must be specified.  Defaults to false.

       enable_klv(bool)
           If set to true, extracts KLV data from VANC and outputs KLV packets.  KLV VANC packets are joined based on MID and PSC
           fields and aggregated into one KLV packet.  Defaults to false.

       Examples

       •   List input devices:

                   ffmpeg -sources decklink

       •   List supported formats:

                   ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'

       •   Capture video clip at 1080i50:

                   ffmpeg -format_code Hi50 -f decklink -i 'Intensity Pro' -c:a copy -c:v copy output.avi

       •   Capture video clip at 1080i50 10 bit:

                   ffmpeg -raw_format yuv422p10 -format_code Hi50 -f decklink -i 'UltraStudio Mini Recorder' -c:a copy -c:v copy output.avi

       •   Capture video clip at 1080i50 with 16 audio channels:

                   ffmpeg -channels 16 -format_code Hi50 -f decklink -i 'UltraStudio Mini Recorder' -c:a copy -c:v copy output.avi

   dshow
       Windows DirectShow input device.

       DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.  Currently only audio and video devices are
       supported.

       Multiple devices may be opened as separate inputs, but they may also be opened on the same input, which should improve
       synchronism between them.

       The input name should be in the format:

               <TYPE>=<NAME>[:<TYPE>=<NAME>]

       where TYPE can be either audio or video, and NAME is the device's name or alternative name..

       Options

       If no options are specified, the device's defaults are used.  If the device does not support the requested options, it will
       fail to open.

       video_size
           Set the video size in the captured video.

       framerate
           Set the frame rate in the captured video.

       sample_rate
           Set the sample rate (in Hz) of the captured audio.

       sample_size
           Set the sample size (in bits) of the captured audio.

       channels
           Set the number of channels in the captured audio.

       list_devices
           If set to true, print a list of devices and exit.

       list_options
           If set to true, print a list of selected device's options and exit.

       video_device_number
           Set video device number for devices with the same name (starts at 0, defaults to 0).

       audio_device_number
           Set audio device number for devices with the same name (starts at 0, defaults to 0).

       pixel_format
           Select pixel format to be used by DirectShow. This may only be set when the video codec is not set or set to rawvideo.

       audio_buffer_size
           Set audio device buffer size in milliseconds (which can directly impact latency, depending on the device).  Defaults to
           using the audio device's default buffer size (typically some multiple of 500ms).  Setting this value too low can degrade
           performance.  See also <http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx>

       video_pin_name
           Select video capture pin to use by name or alternative name.

       audio_pin_name
           Select audio capture pin to use by name or alternative name.

       crossbar_video_input_pin_number
           Select video input pin number for crossbar device. This will be routed to the crossbar device's Video Decoder output
           pin.  Note that changing this value can affect future invocations (sets a new default) until system reboot occurs.

       crossbar_audio_input_pin_number
           Select audio input pin number for crossbar device. This will be routed to the crossbar device's Audio Decoder output
           pin.  Note that changing this value can affect future invocations (sets a new default) until system reboot occurs.

       show_video_device_dialog
           If set to true, before capture starts, popup a display dialog to the end user, allowing them to change video filter
           properties and configurations manually.  Note that for crossbar devices, adjusting values in this dialog may be needed
           at times to toggle between PAL (25 fps) and NTSC (29.97) input frame rates, sizes, interlacing, etc.  Changing these
           values can enable different scan rates/frame rates and avoiding green bars at the bottom, flickering scan lines, etc.
           Note that with some devices, changing these properties can also affect future invocations (sets new defaults) until
           system reboot occurs.

       show_audio_device_dialog
           If set to true, before capture starts, popup a display dialog to the end user, allowing them to change audio filter
           properties and configurations manually.

       show_video_crossbar_connection_dialog
           If set to true, before capture starts, popup a display dialog to the end user, allowing them to manually modify crossbar
           pin routings, when it opens a video device.

       show_audio_crossbar_connection_dialog
           If set to true, before capture starts, popup a display dialog to the end user, allowing them to manually modify crossbar
           pin routings, when it opens an audio device.

       show_analog_tv_tuner_dialog
           If set to true, before capture starts, popup a display dialog to the end user, allowing them to manually modify TV
           channels and frequencies.

       show_analog_tv_tuner_audio_dialog
           If set to true, before capture starts, popup a display dialog to the end user, allowing them to manually modify TV audio
           (like mono vs. stereo, Language A,B or C).

       audio_device_load
           Load an audio capture filter device from file instead of searching it by name. It may load additional parameters too, if
           the filter supports the serialization of its properties to.  To use this an audio capture source has to be specified,
           but it can be anything even fake one.

       audio_device_save
           Save the currently used audio capture filter device and its parameters (if the filter supports it) to a file.  If a file
           with the same name exists it will be overwritten.

       video_device_load
           Load a video capture filter device from file instead of searching it by name. It may load additional parameters too, if
           the filter supports the serialization of its properties to.  To use this a video capture source has to be specified, but
           it can be anything even fake one.

       video_device_save
           Save the currently used video capture filter device and its parameters (if the filter supports it) to a file.  If a file
           with the same name exists it will be overwritten.

       use_video_device_timestamps
           If set to false, the timestamp for video frames will be derived from the wallclock instead of the timestamp provided by
           the capture device. This allows working around devices that provide unreliable timestamps.

       Examples

       •   Print the list of DirectShow supported devices and exit:

                   $ ffmpeg -list_devices true -f dshow -i dummy

       •   Open video device Camera:

                   $ ffmpeg -f dshow -i video="Camera"

       •   Open second video device with name Camera:

                   $ ffmpeg -f dshow -video_device_number 1 -i video="Camera"

       •   Open video device Camera and audio device Microphone:

                   $ ffmpeg -f dshow -i video="Camera":audio="Microphone"

       •   Print the list of supported options in selected device and exit:

                   $ ffmpeg -list_options true -f dshow -i video="Camera"

       •   Specify pin names to capture by name or alternative name, specify alternative device name:

                   $ ffmpeg -f dshow -audio_pin_name "Audio Out" -video_pin_name 2 -i video=video="@device_pnp_\\?\pci#ven_1a0a&dev_6200&subsys_62021461&rev_01#4&e2c7dd6&0&00e1#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\{ca465100-deb0-4d59-818f-8c477184adf6}":audio="Microphone"

       •   Configure a crossbar device, specifying crossbar pins, allow user to adjust video capture properties at startup:

                   $ ffmpeg -f dshow -show_video_device_dialog true -crossbar_video_input_pin_number 0
                        -crossbar_audio_input_pin_number 3 -i video="AVerMedia BDA Analog Capture":audio="AVerMedia BDA Analog Capture"

   fbdev
       Linux framebuffer input device.

       The Linux framebuffer is a graphic hardware-independent abstraction layer to show graphics on a computer monitor, typically
       on the console. It is accessed through a file device node, usually /dev/fb0.

       For more detailed information read the file Documentation/fb/framebuffer.txt included in the Linux source tree.

       See also <http://linux-fbdev.sourceforge.net/>, and fbset(1).

       To record from the framebuffer device /dev/fb0 with ffmpeg:

               ffmpeg -f fbdev -framerate 10 -i /dev/fb0 out.avi

       You can take a single screenshot image with the command:

               ffmpeg -f fbdev -framerate 1 -i /dev/fb0 -frames:v 1 screenshot.jpeg

       Options

       framerate
           Set the frame rate. Default is 25.

   gdigrab
       Win32 GDI-based screen capture device.

       This device allows you to capture a region of the display on Windows.

       There are two options for the input filename:

               desktop

       or

               title=<window_title>

       The first option will capture the entire desktop, or a fixed region of the desktop. The second option will instead capture
       the contents of a single window, regardless of its position on the screen.

       For example, to grab the entire desktop using ffmpeg:

               ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg

       Grab a 640x480 region at position "10,20":

               ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg

       Grab the contents of the window named "Calculator"

               ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg

       Options

       draw_mouse
           Specify whether to draw the mouse pointer. Use the value 0 to not draw the pointer. Default value is 1.

       framerate
           Set the grabbing frame rate. Default value is "ntsc", corresponding to a frame rate of "30000/1001".

       show_region
           Show grabbed region on screen.

           If show_region is specified with 1, then the grabbing region will be indicated on screen. With this option, it is easy
           to know what is being grabbed if only a portion of the screen is grabbed.

           Note that show_region is incompatible with grabbing the contents of a single window.

           For example:

                   ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg

       video_size
           Set the video frame size. The default is to capture the full screen if desktop is selected, or the full window size if
           title=window_title is selected.

       offset_x
           When capturing a region with video_size, set the distance from the left edge of the screen or desktop.

           Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor
           positioned to the left of your primary monitor, you will need to use a negative offset_x value to move the region to
           that monitor.

       offset_y
           When capturing a region with video_size, set the distance from the top edge of the screen or desktop.

           Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor
           positioned above your primary monitor, you will need to use a negative offset_y value to move the region to that
           monitor.

   iec61883
       FireWire DV/HDV input device using libiec61883.

       To enable this input device, you need libiec61883, libraw1394 and libavc1394 installed on your system. Use the configure
       option "--enable-libiec61883" to compile with the device enabled.

       The iec61883 capture device supports capturing from a video device connected via IEEE1394 (FireWire), using libiec61883 and
       the new Linux FireWire stack (juju). This is the default DV/HDV input method in Linux Kernel 2.6.37 and later, since the old
       FireWire stack was removed.

       Specify the FireWire port to be used as input file, or "auto" to choose the first port connected.

       Options

       dvtype
           Override autodetection of DV/HDV. This should only be used if auto detection does not work, or if usage of a different
           device type should be prohibited. Treating a DV device as HDV (or vice versa) will not work and result in undefined
           behavior.  The values auto, dv and hdv are supported.

       dvbuffer
           Set maximum size of buffer for incoming data, in frames. For DV, this is an exact value. For HDV, it is not frame exact,
           since HDV does not have a fixed frame size.

       dvguid
           Select the capture device by specifying its GUID. Capturing will only be performed from the specified device and fails
           if no device with the given GUID is found. This is useful to select the input if multiple devices are connected at the
           same time.  Look at /sys/bus/firewire/devices to find out the GUIDs.

       Examples

       •   Grab and show the input of a FireWire DV/HDV device.

                   ffplay -f iec61883 -i auto

       •   Grab and record the input of a FireWire DV/HDV device, using a packet buffer of 100000 packets if the source is HDV.

                   ffmpeg -f iec61883 -i auto -dvbuffer 100000 out.mpg

   jack
       JACK input device.

       To enable this input device during configuration you need libjack installed on your system.

       A JACK input device creates one or more JACK writable clients, one for each audio channel, with name client_name:input_N,
       where client_name is the name provided by the application, and N is a number which identifies the channel.  Each writable
       client will send the acquired data to the FFmpeg input device.

       Once you have created one or more JACK readable clients, you need to connect them to one or more JACK writable clients.

       To connect or disconnect JACK clients you can use the jack_connect and jack_disconnect programs, or do it through a
       graphical interface, for example with qjackctl.

       To list the JACK clients and their properties you can invoke the command jack_lsp.

       Follows an example which shows how to capture a JACK readable client with ffmpeg.

               # Create a JACK writable client with name "ffmpeg".
               $ ffmpeg -f jack -i ffmpeg -y out.wav

               # Start the sample jack_metro readable client.
               $ jack_metro -b 120 -d 0.2 -f 4000

               # List the current JACK clients.
               $ jack_lsp -c
               system:capture_1
               system:capture_2
               system:playback_1
               system:playback_2
               ffmpeg:input_1
               metro:120_bpm

               # Connect metro to the ffmpeg writable client.
               $ jack_connect metro:120_bpm ffmpeg:input_1

       For more information read: <http://jackaudio.org/>

       Options

       channels
           Set the number of channels. Default is 2.

   kmsgrab
       KMS video input device.

       Captures the KMS scanout framebuffer associated with a specified CRTC or plane as a DRM object that can be passed to other
       hardware functions.

       Requires either DRM master or CAP_SYS_ADMIN to run.

       If you don't understand what all of that means, you probably don't want this.  Look at x11grab instead.

       Options

       device
           DRM device to capture on.  Defaults to /dev/dri/card0.

       format
           Pixel format of the framebuffer.  This can be autodetected if you are running Linux 5.7 or later, but needs to be
           provided for earlier versions.  Defaults to bgr0, which is the most common format used by the Linux console and Xorg X
           server.

       format_modifier
           Format modifier to signal on output frames.  This is necessary to import correctly into some APIs.  It can be
           autodetected if you are running Linux 5.7 or later, but will need to be provided explicitly when needed in earlier
           versions.  See the libdrm documentation for possible values.

       crtc_id
           KMS CRTC ID to define the capture source.  The first active plane on the given CRTC will be used.

       plane_id
           KMS plane ID to define the capture source.  Defaults to the first active plane found if neither crtc_id nor plane_id are
           specified.

       framerate
           Framerate to capture at.  This is not synchronised to any page flipping or framebuffer changes - it just defines the
           interval at which the framebuffer is sampled.  Sampling faster than the framebuffer update rate will generate
           independent frames with the same content.  Defaults to 30.

       Examples

       •   Capture from the first active plane, download the result to normal frames and encode.  This will only work if the
           framebuffer is both linear and mappable - if not, the result may be scrambled or fail to download.

                   ffmpeg -f kmsgrab -i - -vf 'hwdownload,format=bgr0' output.mp4

       •   Capture from CRTC ID 42 at 60fps, map the result to VAAPI, convert to NV12 and encode as H.264.

                   ffmpeg -crtc_id 42 -framerate 60 -f kmsgrab -i - -vf 'hwmap=derive_device=vaapi,scale_vaapi=w=1920:h=1080:format=nv12' -c:v h264_vaapi output.mp4

       •   To capture only part of a plane the output can be cropped - this can be used to capture a single window, as long as it
           has a known absolute position and size.  For example, to capture and encode the middle quarter of a 1920x1080 plane:

                   ffmpeg -f kmsgrab -i - -vf 'hwmap=derive_device=vaapi,crop=960:540:480:270,scale_vaapi=960:540:nv12' -c:v h264_vaapi output.mp4

   lavfi
       Libavfilter input virtual device.

       This input device reads data from the open output pads of a libavfilter filtergraph.

       For each filtergraph open output, the input device will create a corresponding stream which is mapped to the generated
       output. Currently only video data is supported. The filtergraph is specified through the option graph.

       Options

       graph
           Specify the filtergraph to use as input. Each video open output must be labelled by a unique string of the form "outN",
           where N is a number starting from 0 corresponding to the mapped input stream generated by the device.  The first
           unlabelled output is automatically assigned to the "out0" label, but all the others need to be specified explicitly.

           The suffix "+subcc" can be appended to the output label to create an extra stream with the closed captions packets
           attached to that output (experimental; only for EIA-608 / CEA-708 for now).  The subcc streams are created after all the
           normal streams, in the order of the corresponding stream.  For example, if there is "out19+subcc", "out7+subcc" and up
           to "out42", the stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.

           If not specified defaults to the filename specified for the input device.

       graph_file
           Set the filename of the filtergraph to be read and sent to the other filters. Syntax of the filtergraph is the same as
           the one specified by the option graph.

       dumpgraph
           Dump graph to stderr.

       Examples

       •   Create a color video stream and play it back with ffplay:

                   ffplay -f lavfi -graph "color=c=pink [out0]" dummy

       •   As the previous example, but use filename for specifying the graph description, and omit the "out0" label:

                   ffplay -f lavfi color=c=pink

       •   Create three different video test filtered sources and play them:

                   ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3

       •   Read an audio stream from a file using the amovie source and play it back with ffplay:

                   ffplay -f lavfi "amovie=test.wav"

       •   Read an audio stream and a video stream and play it back with ffplay:

                   ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"

       •   Dump decoded frames to images and closed captions to a file (experimental):

                   ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin

   libcdio
       Audio-CD input device based on libcdio.

       To enable this input device during configuration you need libcdio installed on your system. It requires the configure option
       "--enable-libcdio".

       This device allows playing and grabbing from an Audio-CD.

       For example to copy with ffmpeg the entire Audio-CD in /dev/sr0, you may run the command:

               ffmpeg -f libcdio -i /dev/sr0 cd.wav

       Options

       speed
           Set drive reading speed. Default value is 0.

           The speed is specified CD-ROM speed units. The speed is set through the libcdio "cdio_cddap_speed_set" function. On many
           CD-ROM drives, specifying a value too large will result in using the fastest speed.

       paranoia_mode
           Set paranoia recovery mode flags. It accepts one of the following values:

           disable
           verify
           overlap
           neverskip
           full

           Default value is disable.

           For more information about the available recovery modes, consult the paranoia project documentation.

   libdc1394
       IIDC1394 input device, based on libdc1394 and libraw1394.

       Requires the configure option "--enable-libdc1394".

       Options

       framerate
           Set the frame rate. Default is "ntsc", corresponding to a frame rate of "30000/1001".

       pixel_format
           Select the pixel format. Default is "uyvy422".

       video_size
           Set the video size given as a string such as "640x480" or "hd720".  Default is "qvga".

   openal
       The OpenAL input device provides audio capture on all systems with a working OpenAL 1.1 implementation.

       To enable this input device during configuration, you need OpenAL headers and libraries installed on your system, and need
       to configure FFmpeg with "--enable-openal".

       OpenAL headers and libraries should be provided as part of your OpenAL implementation, or as an additional download (an
       SDK). Depending on your installation you may need to specify additional flags via the "--extra-cflags" and "--extra-ldflags"
       for allowing the build system to locate the OpenAL headers and libraries.

       An incomplete list of OpenAL implementations follows:

       Creative
           The official Windows implementation, providing hardware acceleration with supported devices and software fallback.  See
           <http://openal.org/>.

       OpenAL Soft
           Portable, open source (LGPL) software implementation. Includes backends for the most common sound APIs on the Windows,
           Linux, Solaris, and BSD operating systems.  See <http://kcat.strangesoft.net/openal.html>.

       Apple
           OpenAL is part of Core Audio, the official Mac OS X Audio interface.  See
           <http://developer.apple.com/technologies/mac/audio-and-video.html>

       This device allows one to capture from an audio input device handled through OpenAL.

       You need to specify the name of the device to capture in the provided filename. If the empty string is provided, the device
       will automatically select the default device. You can get the list of the supported devices by using the option
       list_devices.

       Options

       channels
           Set the number of channels in the captured audio. Only the values 1 (monaural) and 2 (stereo) are currently supported.
           Defaults to 2.

       sample_size
           Set the sample size (in bits) of the captured audio. Only the values 8 and 16 are currently supported. Defaults to 16.

       sample_rate
           Set the sample rate (in Hz) of the captured audio.  Defaults to 44.1k.

       list_devices
           If set to true, print a list of devices and exit.  Defaults to false.

       Examples

       Print the list of OpenAL supported devices and exit:

               $ ffmpeg -list_devices true -f openal -i dummy out.ogg

       Capture from the OpenAL device DR-BT101 via PulseAudio:

               $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg

       Capture from the default device (note the empty string '' as filename):

               $ ffmpeg -f openal -i '' out.ogg

       Capture from two devices simultaneously, writing to two different files, within the same ffmpeg command:

               $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg

       Note: not all OpenAL implementations support multiple simultaneous capture - try the latest OpenAL Soft if the above does
       not work.

   oss
       Open Sound System input device.

       The filename to provide to the input device is the device node representing the OSS input device, and is usually set to
       /dev/dsp.

       For example to grab from /dev/dsp using ffmpeg use the command:

               ffmpeg -f oss -i /dev/dsp /tmp/oss.wav

       For more information about OSS see: <http://manuals.opensound.com/usersguide/dsp.html>

       Options

       sample_rate
           Set the sample rate in Hz. Default is 48000.

       channels
           Set the number of channels. Default is 2.

   pulse
       PulseAudio input device.

       To enable this output device you need to configure FFmpeg with "--enable-libpulse".

       The filename to provide to the input device is a source device or the string "default"

       To list the PulseAudio source devices and their properties you can invoke the command pactl list sources.

       More information about PulseAudio can be found on <http://www.pulseaudio.org>.

       Options

       server
           Connect to a specific PulseAudio server, specified by an IP address.  Default server is used when not provided.

       name
           Specify the application name PulseAudio will use when showing active clients, by default it is the "LIBAVFORMAT_IDENT"
           string.

       stream_name
           Specify the stream name PulseAudio will use when showing active streams, by default it is "record".

       sample_rate
           Specify the samplerate in Hz, by default 48kHz is used.

       channels
           Specify the channels in use, by default 2 (stereo) is set.

       frame_size
           This option does nothing and is deprecated.

       fragment_size
           Specify the size in bytes of the minimal buffering fragment in PulseAudio, it will affect the audio latency. By default
           it is set to 50 ms amount of data.

       wallclock
           Set the initial PTS using the current time. Default is 1.

       Examples

       Record a stream from default device:

               ffmpeg -f pulse -i default /tmp/pulse.wav

   sndio
       sndio input device.

       To enable this input device during configuration you need libsndio installed on your system.

       The filename to provide to the input device is the device node representing the sndio input device, and is usually set to
       /dev/audio0.

       For example to grab from /dev/audio0 using ffmpeg use the command:

               ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav

       Options

       sample_rate
           Set the sample rate in Hz. Default is 48000.

       channels
           Set the number of channels. Default is 2.

   video4linux2, v4l2
       Video4Linux2 input video device.

       "v4l2" can be used as alias for "video4linux2".

       If FFmpeg is built with v4l-utils support (by using the "--enable-libv4l2" configure option), it is possible to use it with
       the "-use_libv4l2" input device option.

       The name of the device to grab is a file device node, usually Linux systems tend to automatically create such nodes when the
       device (e.g. an USB webcam) is plugged into the system, and has a name of the kind /dev/videoN, where N is a number
       associated to the device.

       Video4Linux2 devices usually support a limited set of widthxheight sizes and frame rates. You can check which are supported
       using -list_formats all for Video4Linux2 devices.  Some devices, like TV cards, support one or more standards. It is
       possible to list all the supported standards using -list_standards all.

       The time base for the timestamps is 1 microsecond. Depending on the kernel version and configuration, the timestamps may be
       derived from the real time clock (origin at the Unix Epoch) or the monotonic clock (origin usually at boot time, unaffected
       by NTP or manual changes to the clock). The -timestamps abs or -ts abs option can be used to force conversion into the real
       time clock.

       Some usage examples of the video4linux2 device with ffmpeg and ffplay:

       •   List supported formats for a video4linux2 device:

                   ffplay -f video4linux2 -list_formats all /dev/video0

       •   Grab and show the input of a video4linux2 device:

                   ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0

       •   Grab and record the input of a video4linux2 device, leave the frame rate and size as previously set:

                   ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg

       For more information about Video4Linux, check <http://linuxtv.org/>.

       Options

       standard
           Set the standard. Must be the name of a supported standard. To get a list of the supported standards, use the
           list_standards option.

       channel
           Set the input channel number. Default to -1, which means using the previously selected channel.

       video_size
           Set the video frame size. The argument must be a string in the form WIDTHxHEIGHT or a valid size abbreviation.

       pixel_format
           Select the pixel format (only valid for raw video input).

       input_format
           Set the preferred pixel format (for raw video) or a codec name.  This option allows one to select the input format, when
           several are available.

       framerate
           Set the preferred video frame rate.

       list_formats
           List available formats (supported pixel formats, codecs, and frame sizes) and exit.

           Available values are:

           all Show all available (compressed and non-compressed) formats.

           raw Show only raw video (non-compressed) formats.

           compressed
               Show only compressed formats.

       list_standards
           List supported standards and exit.

           Available values are:

           all Show all supported standards.

       timestamps, ts
           Set type of timestamps for grabbed frames.

           Available values are:

           default
               Use timestamps from the kernel.

           abs Use absolute timestamps (wall clock).

           mono2abs
               Force conversion from monotonic to absolute timestamps.

           Default value is "default".

       use_libv4l2
           Use libv4l2 (v4l-utils) conversion functions. Default is 0.

   vfwcap
       VfW (Video for Windows) capture input device.

       The filename passed as input is the capture driver number, ranging from 0 to 9. You may use "list" as filename to print a
       list of drivers. Any other filename will be interpreted as device number 0.

       Options

       video_size
           Set the video frame size.

       framerate
           Set the grabbing frame rate. Default value is "ntsc", corresponding to a frame rate of "30000/1001".

   x11grab
       X11 video input device.

       To enable this input device during configuration you need libxcb installed on your system. It will be automatically detected
       during configuration.

       This device allows one to capture a region of an X11 display.

       The filename passed as input has the syntax:

               [<hostname>]:<display_number>.<screen_number>[+<x_offset>,<y_offset>]

       hostname:display_number.screen_number specifies the X11 display name of the screen to grab from. hostname can be omitted,
       and defaults to "localhost". The environment variable DISPLAY contains the default display name.

       x_offset and y_offset specify the offsets of the grabbed area with respect to the top-left border of the X11 screen. They
       default to 0.

       Check the X11 documentation (e.g. man X) for more detailed information.

       Use the xdpyinfo program for getting basic information about the properties of your X11 display (e.g. grep for "name" or
       "dimensions").

       For example to grab from :0.0 using ffmpeg:

               ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg

       Grab at position "10,20":

               ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg

       Options

       select_region
           Specify whether to select the grabbing area graphically using the pointer.  A value of 1 prompts the user to select the
           grabbing area graphically by clicking and dragging. A single click with no dragging will select the whole screen. A
           region with zero width or height will also select the whole screen. This option overwrites the video_size, grab_x, and
           grab_y options. Default value is 0.

       draw_mouse
           Specify whether to draw the mouse pointer. A value of 0 specifies not to draw the pointer. Default value is 1.

       follow_mouse
           Make the grabbed area follow the mouse. The argument can be "centered" or a number of pixels PIXELS.

           When it is specified with "centered", the grabbing region follows the mouse pointer and keeps the pointer at the center
           of region; otherwise, the region follows only when the mouse pointer reaches within PIXELS (greater than zero) to the
           edge of region.

           For example:

                   ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg

           To follow only when the mouse pointer reaches within 100 pixels to edge:

                   ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg

       framerate
           Set the grabbing frame rate. Default value is "ntsc", corresponding to a frame rate of "30000/1001".

       show_region
           Show grabbed region on screen.

           If show_region is specified with 1, then the grabbing region will be indicated on screen. With this option, it is easy
           to know what is being grabbed if only a portion of the screen is grabbed.

       region_border
           Set the region border thickness if -show_region 1 is used.  Range is 1 to 128 and default is 3 (XCB-based x11grab only).

           For example:

                   ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg

           With follow_mouse:

                   ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg

       window_id
           Grab this window, instead of the whole screen. Default value is 0, which maps to the whole screen (root window).

           The id of a window can be found using the xwininfo program, possibly with options -tree and -root.

           If the window is later enlarged, the new area is not recorded. Video ends when the window is closed, unmapped (i.e.,
           iconified) or shrunk beyond the video size (which defaults to the initial window size).

           This option disables options follow_mouse and select_region.

       video_size
           Set the video frame size. Default is the full desktop or window.

       grab_x
       grab_y
           Set the grabbing region coordinates. They are expressed as offset from the top left corner of the X11 window and
           correspond to the x_offset and y_offset parameters in the device name. The default value for both options is 0.

RESAMPLER OPTIONS
       The audio resampler supports the following named options.

       Options may be set by specifying -option value in the FFmpeg tools, option=value for the aresample filter, by setting the
       value explicitly in the "SwrContext" options or using the libavutil/opt.h API for programmatic use.

       ich, in_channel_count
           Set the number of input channels. Default value is 0. Setting this value is not mandatory if the corresponding channel
           layout in_channel_layout is set.

       och, out_channel_count
           Set the number of output channels. Default value is 0. Setting this value is not mandatory if the corresponding channel
           layout out_channel_layout is set.

       uch, used_channel_count
           Set the number of used input channels. Default value is 0. This option is only used for special remapping.

       isr, in_sample_rate
           Set the input sample rate. Default value is 0.

       osr, out_sample_rate
           Set the output sample rate. Default value is 0.

       isf, in_sample_fmt
           Specify the input sample format. It is set by default to "none".

       osf, out_sample_fmt
           Specify the output sample format. It is set by default to "none".

       tsf, internal_sample_fmt
           Set the internal sample format. Default value is "none".  This will automatically be chosen when it is not explicitly
           set.

       icl, in_channel_layout
       ocl, out_channel_layout
           Set the input/output channel layout.

           See the Channel Layout section in the ffmpeg-utils(1) manual for the required syntax.

       clev, center_mix_level
           Set the center mix level. It is a value expressed in deciBel, and must be in the interval [-32,32].

       slev, surround_mix_level
           Set the surround mix level. It is a value expressed in deciBel, and must be in the interval [-32,32].

       lfe_mix_level
           Set LFE mix into non LFE level. It is used when there is a LFE input but no LFE output. It is a value expressed in
           deciBel, and must be in the interval [-32,32].

       rmvol, rematrix_volume
           Set rematrix volume. Default value is 1.0.

       rematrix_maxval
           Set maximum output value for rematrixing.  This can be used to prevent clipping vs. preventing volume reduction.  A
           value of 1.0 prevents clipping.

       flags, swr_flags
           Set flags used by the converter. Default value is 0.

           It supports the following individual flags:

           res force resampling, this flag forces resampling to be used even when the input and output sample rates match.

       dither_scale
           Set the dither scale. Default value is 1.

       dither_method
           Set dither method. Default value is 0.

           Supported values:

           rectangular
               select rectangular dither

           triangular
               select triangular dither

           triangular_hp
               select triangular dither with high pass

           lipshitz
               select Lipshitz noise shaping dither.

           shibata
               select Shibata noise shaping dither.

           low_shibata
               select low Shibata noise shaping dither.

           high_shibata
               select high Shibata noise shaping dither.

           f_weighted
               select f-weighted noise shaping dither

           modified_e_weighted
               select modified-e-weighted noise shaping dither

           improved_e_weighted
               select improved-e-weighted noise shaping dither

       resampler
           Set resampling engine. Default value is swr.

           Supported values:

           swr select the native SW Resampler; filter options precision and cheby are not applicable in this case.

           soxr
               select the SoX Resampler (where available); compensation, and filter options filter_size, phase_shift,
               exact_rational, filter_type & kaiser_beta, are not applicable in this case.

       filter_size
           For swr only, set resampling filter size, default value is 32.

       phase_shift
           For swr only, set resampling phase shift, default value is 10, and must be in the interval [0,30].

       linear_interp
           Use linear interpolation when enabled (the default). Disable it if you want to preserve speed instead of quality when
           exact_rational fails.

       exact_rational
           For swr only, when enabled, try to use exact phase_count based on input and output sample rate. However, if it is larger
           than "1 << phase_shift", the phase_count will be "1 << phase_shift" as fallback. Default is enabled.

       cutoff
           Set cutoff frequency (swr: 6dB point; soxr: 0dB point) ratio; must be a float value between 0 and 1.  Default value is
           0.97 with swr, and 0.91 with soxr (which, with a sample-rate of 44100, preserves the entire audio band to 20kHz).

       precision
           For soxr only, the precision in bits to which the resampled signal will be calculated.  The default value of 20 (which,
           with suitable dithering, is appropriate for a destination bit-depth of 16) gives SoX's 'High Quality'; a value of 28
           gives SoX's 'Very High Quality'.

       cheby
           For soxr only, selects passband rolloff none (Chebyshev) & higher-precision approximation for 'irrational' ratios.
           Default value is 0.

       async
           For swr only, simple 1 parameter audio sync to timestamps using stretching, squeezing, filling and trimming. Setting
           this to 1 will enable filling and trimming, larger values represent the maximum amount in samples that the data may be
           stretched or squeezed for each second.  Default value is 0, thus no compensation is applied to make the samples match
           the audio timestamps.

       first_pts
           For swr only, assume the first pts should be this value. The time unit is 1 / sample rate.  This allows for
           padding/trimming at the start of stream. By default, no assumption is made about the first frame's expected pts, so no
           padding or trimming is done. For example, this could be set to 0 to pad the beginning with silence if an audio stream
           starts after the video stream or to trim any samples with a negative pts due to encoder delay.

       min_comp
           For swr only, set the minimum difference between timestamps and audio data (in seconds) to trigger
           stretching/squeezing/filling or trimming of the data to make it match the timestamps. The default is that
           stretching/squeezing/filling and trimming is disabled (min_comp = "FLT_MAX").

       min_hard_comp
           For swr only, set the minimum difference between timestamps and audio data (in seconds) to trigger adding/dropping
           samples to make it match the timestamps.  This option effectively is a threshold to select between hard (trim/fill) and
           soft (squeeze/stretch) compensation. Note that all compensation is by default disabled through min_comp.  The default is
           0.1.

       comp_duration
           For swr only, set duration (in seconds) over which data is stretched/squeezed to make it match the timestamps. Must be a
           non-negative double float value, default value is 1.0.

       max_soft_comp
           For swr only, set maximum factor by which data is stretched/squeezed to make it match the timestamps. Must be a non-
           negative double float value, default value is 0.

       matrix_encoding
           Select matrixed stereo encoding.

           It accepts the following values:

           none
               select none

           dolby
               select Dolby

           dplii
               select Dolby Pro Logic II

           Default value is "none".

       filter_type
           For swr only, select resampling filter type. This only affects resampling operations.

           It accepts the following values:

           cubic
               select cubic

           blackman_nuttall
               select Blackman Nuttall windowed sinc

           kaiser
               select Kaiser windowed sinc

       kaiser_beta
           For swr only, set Kaiser window beta value. Must be a double float value in the interval [2,16], default value is 9.

       output_sample_bits
           For swr only, set number of used output sample bits for dithering. Must be an integer in the interval [0,64], default
           value is 0, which means it's not used.

SCALER OPTIONS
       The video scaler supports the following named options.

       Options may be set by specifying -option value in the FFmpeg tools, with a few API-only exceptions noted below.  For
       programmatic use, they can be set explicitly in the "SwsContext" options or through the libavutil/opt.h API.

       sws_flags
           Set the scaler flags. This is also used to set the scaling algorithm. Only a single algorithm should be selected.
           Default value is bicubic.

           It accepts the following values:

           fast_bilinear
               Select fast bilinear scaling algorithm.

           bilinear
               Select bilinear scaling algorithm.

           bicubic
               Select bicubic scaling algorithm.

           experimental
               Select experimental scaling algorithm.

           neighbor
               Select nearest neighbor rescaling algorithm.

           area
               Select averaging area rescaling algorithm.

           bicublin
               Select bicubic scaling algorithm for the luma component, bilinear for chroma components.

           gauss
               Select Gaussian rescaling algorithm.

           sinc
               Select sinc rescaling algorithm.

           lanczos
               Select Lanczos rescaling algorithm. The default width (alpha) is 3 and can be changed by setting "param0".

           spline
               Select natural bicubic spline rescaling algorithm.

           print_info
               Enable printing/debug logging.

           accurate_rnd
               Enable accurate rounding.

           full_chroma_int
               Enable full chroma interpolation.

           full_chroma_inp
               Select full chroma input.

           bitexact
               Enable bitexact output.

       srcw (API only)
           Set source width.

       srch (API only)
           Set source height.

       dstw (API only)
           Set destination width.

       dsth (API only)
           Set destination height.

       src_format (API only)
           Set source pixel format (must be expressed as an integer).

       dst_format (API only)
           Set destination pixel format (must be expressed as an integer).

       src_range (boolean)
           If value is set to 1, indicates source is full range. Default value is 0, which indicates source is limited range.

       dst_range (boolean)
           If value is set to 1, enable full range for destination. Default value is 0, which enables limited range.

       param0, param1
           Set scaling algorithm parameters. The specified values are specific of some scaling algorithms and ignored by others.
           The specified values are floating point number values.

       sws_dither
           Set the dithering algorithm. Accepts one of the following values. Default value is auto.

           auto
               automatic choice

           none
               no dithering

           bayer
               bayer dither

           ed  error diffusion dither

           a_dither
               arithmetic dither, based using addition

           x_dither
               arithmetic dither, based using xor (more random/less apparent patterning that a_dither).

       alphablend
           Set the alpha blending to use when the input has alpha but the output does not.  Default value is none.

           uniform_color
               Blend onto a uniform background color

           checkerboard
               Blend onto a checkerboard

           none
               No blending

FILTERING INTRODUCTION
       Filtering in FFmpeg is enabled through the libavfilter library.

       In libavfilter, a filter can have multiple inputs and multiple outputs.  To illustrate the sorts of things that are
       possible, we consider the following filtergraph.

                               [main]
               input --> split ---------------------> overlay --> output
                           |                             ^
                           |[tmp]                  [flip]|
                           +-----> crop --> vflip -------+

       This filtergraph splits the input stream in two streams, then sends one stream through the crop filter and the vflip filter,
       before merging it back with the other stream by overlaying it on top. You can use the following command to achieve this:

               ffmpeg -i INPUT -vf "split [main][tmp]; [tmp] crop=iw:ih/2:0:0, vflip [flip]; [main][flip] overlay=0:H/2" OUTPUT

       The result will be that the top half of the video is mirrored onto the bottom half of the output video.

       Filters in the same linear chain are separated by commas, and distinct linear chains of filters are separated by semicolons.
       In our example, crop,vflip are in one linear chain, split and overlay are separately in another. The points where the linear
       chains join are labelled by names enclosed in square brackets. In the example, the split filter generates two outputs that
       are associated to the labels [main] and [tmp].

       The stream sent to the second output of split, labelled as [tmp], is processed through the crop filter, which crops away the
       lower half part of the video, and then vertically flipped. The overlay filter takes in input the first unchanged output of
       the split filter (which was labelled as [main]), and overlay on its lower half the output generated by the crop,vflip
       filterchain.

       Some filters take in input a list of parameters: they are specified after the filter name and an equal sign, and are
       separated from each other by a colon.

       There exist so-called source filters that do not have an audio/video input, and sink filters that will not have audio/video
       output.

GRAPH
       The graph2dot program included in the FFmpeg tools directory can be used to parse a filtergraph description and issue a
       corresponding textual representation in the dot language.

       Invoke the command:

               graph2dot -h

       to see how to use graph2dot.

       You can then pass the dot description to the dot program (from the graphviz suite of programs) and obtain a graphical
       representation of the filtergraph.

       For example the sequence of commands:

               echo <GRAPH_DESCRIPTION> | \
               tools/graph2dot -o graph.tmp && \
               dot -Tpng graph.tmp -o graph.png && \
               display graph.png

       can be used to create and display an image representing the graph described by the GRAPH_DESCRIPTION string. Note that this
       string must be a complete self-contained graph, with its inputs and outputs explicitly defined.  For example if your command
       line is of the form:

               ffmpeg -i infile -vf scale=640:360 outfile

       your GRAPH_DESCRIPTION string will need to be of the form:

               nullsrc,scale=640:360,nullsink

       you may also need to set the nullsrc parameters and add a format filter in order to simulate a specific input file.

FILTERGRAPH DESCRIPTION
       A filtergraph is a directed graph of connected filters. It can contain cycles, and there can be multiple links between a
       pair of filters. Each link has one input pad on one side connecting it to one filter from which it takes its input, and one
       output pad on the other side connecting it to one filter accepting its output.

       Each filter in a filtergraph is an instance of a filter class registered in the application, which defines the features and
       the number of input and output pads of the filter.

       A filter with no input pads is called a "source", and a filter with no output pads is called a "sink".

   Filtergraph syntax
       A filtergraph has a textual representation, which is recognized by the -filter/-vf/-af and -filter_complex options in ffmpeg
       and -vf/-af in ffplay, and by the "avfilter_graph_parse_ptr()" function defined in libavfilter/avfilter.h.

       A filterchain consists of a sequence of connected filters, each one connected to the previous one in the sequence. A
       filterchain is represented by a list of ","-separated filter descriptions.

       A filtergraph consists of a sequence of filterchains. A sequence of filterchains is represented by a list of ";"-separated
       filterchain descriptions.

       A filter is represented by a string of the form:
       [in_link_1]...[in_link_N]filter_name@id=arguments[out_link_1]...[out_link_M]

       filter_name is the name of the filter class of which the described filter is an instance of, and has to be the name of one
       of the filter classes registered in the program optionally followed by "@id".  The name of the filter class is optionally
       followed by a string "=arguments".

       arguments is a string which contains the parameters used to initialize the filter instance. It may have one of two forms:

       •   A ':'-separated list of key=value pairs.

       •   A ':'-separated list of value. In this case, the keys are assumed to be the option names in the order they are declared.
           E.g. the "fade" filter declares three options in this order -- type, start_frame and nb_frames. Then the parameter list
           in:0:30 means that the value in is assigned to the option type, 0 to start_frame and 30 to nb_frames.

       •   A ':'-separated list of mixed direct value and long key=value pairs. The direct value must precede the key=value pairs,
           and follow the same constraints order of the previous point. The following key=value pairs can be set in any preferred
           order.

       If the option value itself is a list of items (e.g. the "format" filter takes a list of pixel formats), the items in the
       list are usually separated by |.

       The list of arguments can be quoted using the character ' as initial and ending mark, and the character \ for escaping the
       characters within the quoted text; otherwise the argument string is considered terminated when the next special character
       (belonging to the set []=;,) is encountered.

       The name and arguments of the filter are optionally preceded and followed by a list of link labels.  A link label allows one
       to name a link and associate it to a filter output or input pad. The preceding labels in_link_1 ... in_link_N, are
       associated to the filter input pads, the following labels out_link_1 ... out_link_M, are associated to the output pads.

       When two link labels with the same name are found in the filtergraph, a link between the corresponding input and output pad
       is created.

       If an output pad is not labelled, it is linked by default to the first unlabelled input pad of the next filter in the
       filterchain.  For example in the filterchain

               nullsrc, split[L1], [L2]overlay, nullsink

       the split filter instance has two output pads, and the overlay filter instance two input pads. The first output pad of split
       is labelled "L1", the first input pad of overlay is labelled "L2", and the second output pad of split is linked to the
       second input pad of overlay, which are both unlabelled.

       In a filter description, if the input label of the first filter is not specified, "in" is assumed; if the output label of
       the last filter is not specified, "out" is assumed.

       In a complete filterchain all the unlabelled filter input and output pads must be connected. A filtergraph is considered
       valid if all the filter input and output pads of all the filterchains are connected.

       Libavfilter will automatically insert scale filters where format conversion is required. It is possible to specify swscale
       flags for those automatically inserted scalers by prepending "sws_flags=flags;" to the filtergraph description.

       Here is a BNF description of the filtergraph syntax:

               <NAME>             ::= sequence of alphanumeric characters and '_'
               <FILTER_NAME>      ::= <NAME>["@"<NAME>]
               <LINKLABEL>        ::= "[" <NAME> "]"
               <LINKLABELS>       ::= <LINKLABEL> [<LINKLABELS>]
               <FILTER_ARGUMENTS> ::= sequence of chars (possibly quoted)
               <FILTER>           ::= [<LINKLABELS>] <FILTER_NAME> ["=" <FILTER_ARGUMENTS>] [<LINKLABELS>]
               <FILTERCHAIN>      ::= <FILTER> [,<FILTERCHAIN>]
               <FILTERGRAPH>      ::= [sws_flags=<flags>;] <FILTERCHAIN> [;<FILTERGRAPH>]

   Notes on filtergraph escaping
       Filtergraph description composition entails several levels of escaping. See the "Quoting and escaping" section in the
       ffmpeg-utils(1) manual for more information about the employed escaping procedure.

       A first level escaping affects the content of each filter option value, which may contain the special character ":" used to
       separate values, or one of the escaping characters "\'".

       A second level escaping affects the whole filter description, which may contain the escaping characters "\'" or the special
       characters "[],;" used by the filtergraph description.

       Finally, when you specify a filtergraph on a shell commandline, you need to perform a third level escaping for the shell
       special characters contained within it.

       For example, consider the following string to be embedded in the drawtext filter description text value:

               this is a 'string': may contain one, or more, special characters

       This string contains the "'" special escaping character, and the ":" special character, so it needs to be escaped in this
       way:

               text=this is a \'string\'\: may contain one, or more, special characters

       A second level of escaping is required when embedding the filter description in a filtergraph description, in order to
       escape all the filtergraph special characters. Thus the example above becomes:

               drawtext=text=this is a \\\'string\\\'\\: may contain one\, or more\, special characters

       (note that in addition to the "\'" escaping special characters, also "," needs to be escaped).

       Finally an additional level of escaping is needed when writing the filtergraph description in a shell command, which depends
       on the escaping rules of the adopted shell. For example, assuming that "\" is special and needs to be escaped with another
       "\", the previous string will finally result in:

               -vf "drawtext=text=this is a \\\\\\'string\\\\\\'\\\\: may contain one\\, or more\\, special characters"

TIMELINE EDITING
       Some filters support a generic enable option. For the filters supporting timeline editing, this option can be set to an
       expression which is evaluated before sending a frame to the filter. If the evaluation is non-zero, the filter will be
       enabled, otherwise the frame will be sent unchanged to the next filter in the filtergraph.

       The expression accepts the following values:

       t   timestamp expressed in seconds, NAN if the input timestamp is unknown

       n   sequential number of the input frame, starting from 0

       pos the position in the file of the input frame, NAN if unknown

       w
       h   width and height of the input frame if video

       Additionally, these filters support an enable command that can be used to re-define the expression.

       Like any other filtering option, the enable option follows the same rules.

       For example, to enable a blur filter (smartblur) from 10 seconds to 3 minutes, and a curves filter starting at 3 seconds:

               smartblur = enable='between(t,10,3*60)',
               curves    = enable='gte(t,3)' : preset=cross_process

       See "ffmpeg -filters" to view which filters have timeline support.

CHANGING OPTIONS AT RUNTIME WITH A COMMAND
       Some options can be changed during the operation of the filter using a command. These options are marked 'T' on the output
       of ffmpeg -h filter=<name of filter>.  The name of the command is the name of the option and the argument is the new value.

OPTIONS FOR FILTERS WITH SEVERAL INPUTS
       Some filters with several inputs support a common set of options.  These options can only be set by name, not with the short
       notation.

       eof_action
           The action to take when EOF is encountered on the secondary input; it accepts one of the following values:

           repeat
               Repeat the last frame (the default).

           endall
               End both streams.

           pass
               Pass the main input through.

       shortest
           If set to 1, force the output to terminate when the shortest input terminates. Default value is 0.

       repeatlast
           If set to 1, force the filter to extend the last frame of secondary streams until the end of the primary stream. A value
           of 0 disables this behavior.  Default value is 1.

AUDIO FILTERS
       When you configure your FFmpeg build, you can disable any of the existing filters using "--disable-filters".  The configure
       output will show the audio filters included in your build.

       Below is a description of the currently available audio filters.

   acompressor
       A compressor is mainly used to reduce the dynamic range of a signal.  Especially modern music is mostly compressed at a high
       ratio to improve the overall loudness. It's done to get the highest attention of a listener, "fatten" the sound and bring
       more "power" to the track.  If a signal is compressed too much it may sound dull or "dead" afterwards or it may start to
       "pump" (which could be a powerful effect but can also destroy a track completely).  The right compression is the key to
       reach a professional sound and is the high art of mixing and mastering. Because of its complex settings it may take a long
       time to get the right feeling for this kind of effect.

       Compression is done by detecting the volume above a chosen level "threshold" and dividing it by the factor set with "ratio".
       So if you set the threshold to -12dB and your signal reaches -6dB a ratio of 2:1 will result in a signal at -9dB. Because an
       exact manipulation of the signal would cause distortion of the waveform the reduction can be levelled over the time. This is
       done by setting "Attack" and "Release".  "attack" determines how long the signal has to rise above the threshold before any
       reduction will occur and "release" sets the time the signal has to fall below the threshold to reduce the reduction again.
       Shorter signals than the chosen attack time will be left untouched.  The overall reduction of the signal can be made up
       afterwards with the "makeup" setting. So compressing the peaks of a signal about 6dB and raising the makeup to this level
       results in a signal twice as loud than the source. To gain a softer entry in the compression the "knee" flattens the hard
       edge at the threshold in the range of the chosen decibels.

       The filter accepts the following options:

       level_in
           Set input gain. Default is 1. Range is between 0.015625 and 64.

       mode
           Set mode of compressor operation. Can be "upward" or "downward".  Default is "downward".

       threshold
           If a signal of stream rises above this level it will affect the gain reduction.  By default it is 0.125. Range is
           between 0.00097563 and 1.

       ratio
           Set a ratio by which the signal is reduced. 1:2 means that if the level rose 4dB above the threshold, it will be only
           2dB above after the reduction.  Default is 2. Range is between 1 and 20.

       attack
           Amount of milliseconds the signal has to rise above the threshold before gain reduction starts. Default is 20. Range is
           between 0.01 and 2000.

       release
           Amount of milliseconds the signal has to fall below the threshold before reduction is decreased again. Default is 250.
           Range is between 0.01 and 9000.

       makeup
           Set the amount by how much signal will be amplified after processing.  Default is 1. Range is from 1 to 64.

       knee
           Curve the sharp knee around the threshold to enter gain reduction more softly.  Default is 2.82843. Range is between 1
           and 8.

       link
           Choose if the "average" level between all channels of input stream or the louder("maximum") channel of input stream
           affects the reduction. Default is "average".

       detection
           Should the exact signal be taken in case of "peak" or an RMS one in case of "rms". Default is "rms" which is mostly
           smoother.

       mix How much to use compressed signal in output. Default is 1.  Range is between 0 and 1.

       Commands

       This filter supports the all above options as commands.

   acontrast
       Simple audio dynamic range compression/expansion filter.

       The filter accepts the following options:

       contrast
           Set contrast. Default is 33. Allowed range is between 0 and 100.

   acopy
       Copy the input audio source unchanged to the output. This is mainly useful for testing purposes.

   acrossfade
       Apply cross fade from one input audio stream to another input audio stream.  The cross fade is applied for specified
       duration near the end of first stream.

       The filter accepts the following options:

       nb_samples, ns
           Specify the number of samples for which the cross fade effect has to last.  At the end of the cross fade effect the
           first input audio will be completely silent. Default is 44100.

       duration, d
           Specify the duration of the cross fade effect. See the Time duration section in the ffmpeg-utils(1) manual for the
           accepted syntax.  By default the duration is determined by nb_samples.  If set this option is used instead of
           nb_samples.

       overlap, o
           Should first stream end overlap with second stream start. Default is enabled.

       curve1
           Set curve for cross fade transition for first stream.

       curve2
           Set curve for cross fade transition for second stream.

           For description of available curve types see afade filter description.

       Examples

       •   Cross fade from one input to another:

                   ffmpeg -i first.flac -i second.flac -filter_complex acrossfade=d=10:c1=exp:c2=exp output.flac

       •   Cross fade from one input to another but without overlapping:

                   ffmpeg -i first.flac -i second.flac -filter_complex acrossfade=d=10:o=0:c1=exp:c2=exp output.flac

   acrossover
       Split audio stream into several bands.

       This filter splits audio stream into two or more frequency ranges.  Summing all streams back will give flat output.

       The filter accepts the following options:

       split
           Set split frequencies. Those must be positive and increasing.

       order
           Set filter order for each band split. This controls filter roll-off or steepness of filter transfer function.  Available
           values are:

           2nd 12 dB per octave.

           4th 24 dB per octave.

           6th 36 dB per octave.

           8th 48 dB per octave.

           10th
               60 dB per octave.

           12th
               72 dB per octave.

           14th
               84 dB per octave.

           16th
               96 dB per octave.

           18th
               108 dB per octave.

           20th
               120 dB per octave.

           Default is 4th.

       level
           Set input gain level. Allowed range is from 0 to 1. Default value is 1.

       gains
           Set output gain for each band. Default value is 1 for all bands.

       precision
           Set which precision to use when processing samples.

           auto
               Auto pick internal sample format depending on other filters.

           float
               Always use single-floating point precision sample format.

           double
               Always use double-floating point precision sample format.

           Default value is "auto".

       Examples

       •   Split input audio stream into two bands (low and high) with split frequency of 1500 Hz, each band will be in separate
           stream:

                   ffmpeg -i in.flac -filter_complex 'acrossover=split=1500[LOW][HIGH]' -map '[LOW]' low.wav -map '[HIGH]' high.wav

       •   Same as above, but with higher filter order:

                   ffmpeg -i in.flac -filter_complex 'acrossover=split=1500:order=8th[LOW][HIGH]' -map '[LOW]' low.wav -map '[HIGH]' high.wav

       •   Same as above, but also with additional middle band (frequencies between 1500 and 8000):

                   ffmpeg -i in.flac -filter_complex 'acrossover=split=1500 8000:order=8th[LOW][MID][HIGH]' -map '[LOW]' low.wav -map '[MID]' mid.wav -map '[HIGH]' high.wav

   acrusher
       Reduce audio bit resolution.

       This filter is bit crusher with enhanced functionality. A bit crusher is used to audibly reduce number of bits an audio
       signal is sampled with. This doesn't change the bit depth at all, it just produces the effect. Material reduced in bit depth
       sounds more harsh and "digital".  This filter is able to even round to continuous values instead of discrete bit depths.
       Additionally it has a D/C offset which results in different crushing of the lower and the upper half of the signal.  An
       Anti-Aliasing setting is able to produce "softer" crushing sounds.

       Another feature of this filter is the logarithmic mode.  This setting switches from linear distances between bits to
       logarithmic ones.  The result is a much more "natural" sounding crusher which doesn't gate low signals for example. The
       human ear has a logarithmic perception, so this kind of crushing is much more pleasant.  Logarithmic crushing is also able
       to get anti-aliased.

       The filter accepts the following options:

       level_in
           Set level in.

       level_out
           Set level out.

       bits
           Set bit reduction.

       mix Set mixing amount.

       mode
           Can be linear: "lin" or logarithmic: "log".

       dc  Set DC.

       aa  Set anti-aliasing.

       samples
           Set sample reduction.

       lfo Enable LFO. By default disabled.

       lforange
           Set LFO range.

       lforate
           Set LFO rate.

       Commands

       This filter supports the all above options as commands.

   acue
       Delay audio filtering until a given wallclock timestamp. See the cue filter.

   adeclick
       Remove impulsive noise from input audio.

       Samples detected as impulsive noise are replaced by interpolated samples using autoregressive modelling.

       window, w
           Set window size, in milliseconds. Allowed range is from 10 to 100. Default value is 55 milliseconds.  This sets size of
           window which will be processed at once.

       overlap, o
           Set window overlap, in percentage of window size. Allowed range is from 50 to 95. Default value is 75 percent.  Setting
           this to a very high value increases impulsive noise removal but makes whole process much slower.

       arorder, a
           Set autoregression order, in percentage of window size. Allowed range is from 0 to 25. Default value is 2 percent. This
           option also controls quality of interpolated samples using neighbour good samples.

       threshold, t
           Set threshold value. Allowed range is from 1 to 100.  Default value is 2.  This controls the strength of impulsive noise
           which is going to be removed.  The lower value, the more samples will be detected as impulsive noise.

       burst, b
           Set burst fusion, in percentage of window size. Allowed range is 0 to 10. Default value is 2.  If any two samples
           detected as noise are spaced less than this value then any sample between those two samples will be also detected as
           noise.

       method, m
           Set overlap method.

           It accepts the following values:

           add, a
               Select overlap-add method. Even not interpolated samples are slightly changed with this method.

           save, s
               Select overlap-save method. Not interpolated samples remain unchanged.

           Default value is "a".

   adeclip
       Remove clipped samples from input audio.

       Samples detected as clipped are replaced by interpolated samples using autoregressive modelling.

       window, w
           Set window size, in milliseconds. Allowed range is from 10 to 100.  Default value is 55 milliseconds.  This sets size of
           window which will be processed at once.

       overlap, o
           Set window overlap, in percentage of window size. Allowed range is from 50 to 95. Default value is 75 percent.

       arorder, a
           Set autoregression order, in percentage of window size. Allowed range is from 0 to 25. Default value is 8 percent. This
           option also controls quality of interpolated samples using neighbour good samples.

       threshold, t
           Set threshold value. Allowed range is from 1 to 100.  Default value is 10. Higher values make clip detection less
           aggressive.

       hsize, n
           Set size of histogram used to detect clips. Allowed range is from 100 to 9999.  Default value is 1000. Higher values
           make clip detection less aggressive.

       method, m
           Set overlap method.

           It accepts the following values:

           add, a
               Select overlap-add method. Even not interpolated samples are slightly changed with this method.

           save, s
               Select overlap-save method. Not interpolated samples remain unchanged.

           Default value is "a".

   adecorrelate
       Apply decorrelation to input audio stream.

       The filter accepts the following options:

       stages
           Set decorrelation stages of filtering. Allowed range is from 1 to 16. Default value is 6.

       seed
           Set random seed used for setting delay in samples across channels.

   adelay
       Delay one or more audio channels.

       Samples in delayed channel are filled with silence.

       The filter accepts the following option:

       delays
           Set list of delays in milliseconds for each channel separated by '|'.  Unused delays will be silently ignored. If number
           of given delays is smaller than number of channels all remaining channels will not be delayed.  If you want to delay
           exact number of samples, append 'S' to number.  If you want instead to delay in seconds, append 's' to number.

       all Use last set delay for all remaining channels. By default is disabled.  This option if enabled changes how option
           "delays" is interpreted.

       Examples

       •   Delay first channel by 1.5 seconds, the third channel by 0.5 seconds and leave the second channel (and any other
           channels that may be present) unchanged.

                   adelay=1500|0|500

       •   Delay second channel by 500 samples, the third channel by 700 samples and leave the first channel (and any other
           channels that may be present) unchanged.

                   adelay=0|500S|700S

       •   Delay all channels by same number of samples:

                   adelay=delays=64S:all=1

   adenorm
       Remedy denormals in audio by adding extremely low-level noise.

       This filter shall be placed before any filter that can produce denormals.

       A description of the accepted parameters follows.

       level
           Set level of added noise in dB. Default is "-351".  Allowed range is from -451 to -90.

       type
           Set type of added noise.

           dc  Add DC signal.

           ac  Add AC signal.

           square
               Add square signal.

           pulse
               Add pulse signal.

           Default is "dc".

       Commands

       This filter supports the all above options as commands.

   aderivative, aintegral
       Compute derivative/integral of audio stream.

       Applying both filters one after another produces original audio.

   adynamicequalizer
       Apply dynamic equalization to input audio stream.

       A description of the accepted options follows.

       threshold
           Set the detection threshold used to trigger equalization.  Threshold detection is using bandpass filter.  Default value
           is 0. Allowed range is from 0 to 100.

       dfrequency
           Set the detection frequency in Hz used for bandpass filter used to trigger equalization.  Default value is 1000 Hz.
           Allowed range is between 2 and 1000000 Hz.

       dqfactor
           Set the detection resonance factor for bandpass filter used to trigger equalization.  Default value is 1. Allowed range
           is from 0.001 to 1000.

       tfrequency
           Set the target frequency of equalization filter.  Default value is 1000 Hz. Allowed range is between 2 and 1000000 Hz.

       tqfactor
           Set the target resonance factor for target equalization filter.  Default value is 1. Allowed range is from 0.001 to
           1000.

       attack
           Set the amount of milliseconds the signal from detection has to rise above the detection threshold before equalization
           starts.  Default is 20. Allowed range is between 1 and 2000.

       release
           Set the amount of milliseconds the signal from detection has to fall below the detection threshold before equalization
           ends.  Default is 200. Allowed range is between 1 and 2000.

       knee
           Curve the sharp knee around the detection threshold to calculate equalization gain more softly.  Default is 1. Allowed
           range is between 0 and 8.

       ratio
           Set the ratio by which the equalization gain is raised.  Default is 1. Allowed range is between 1 and 20.

       makeup
           Set the makeup offset in dB by which the equalization gain is raised.  Default is 0. Allowed range is between 0 and 30.

       range
           Set the max allowed cut/boost amount in dB. Default is 0.  Allowed range is from 0 to 200.

       slew
           Set the slew factor. Default is 1. Allowed range is from 1 to 200.

       mode
           Set the mode of filter operation, can be one of the following:

           listen
               Output only isolated bandpass signal.

           cut Cut frequencies above detection threshold.

           boost
               Boost frequencies bellow detection threshold.

           Default mode is cut.

       tftype
           Set the type of target filter, can be one of the following:

           bell
           lowshelf
           highshelf

           Default type is bell.

       Commands

       This filter supports the all above options as commands.

   adynamicsmooth
       Apply dynamic smoothing to input audio stream.

       A description of the accepted options follows.

       sensitivity
           Set an amount of sensitivity to frequency fluctations. Default is 2.  Allowed range is from 0 to 1e+06.

       basefreq
           Set a base frequency for smoothing. Default value is 22050.  Allowed range is from 2 to 1e+06.

       Commands

       This filter supports the all above options as commands.

   aecho
       Apply echoing to the input audio.

       Echoes are reflected sound and can occur naturally amongst mountains (and sometimes large buildings) when talking or
       shouting; digital echo effects emulate this behaviour and are often used to help fill out the sound of a single instrument
       or vocal. The time difference between the original signal and the reflection is the "delay", and the loudness of the
       reflected signal is the "decay".  Multiple echoes can have different delays and decays.

       A description of the accepted parameters follows.

       in_gain
           Set input gain of reflected signal. Default is 0.6.

       out_gain
           Set output gain of reflected signal. Default is 0.3.

       delays
           Set list of time intervals in milliseconds between original signal and reflections separated by '|'. Allowed range for
           each "delay" is "(0 - 90000.0]".  Default is 1000.

       decays
           Set list of loudness of reflected signals separated by '|'.  Allowed range for each "decay" is "(0 - 1.0]".  Default is
           0.5.

       Examples

       •   Make it sound as if there are twice as many instruments as are actually playing:

                   aecho=0.8:0.88:60:0.4

       •   If delay is very short, then it sounds like a (metallic) robot playing music:

                   aecho=0.8:0.88:6:0.4

       •   A longer delay will sound like an open air concert in the mountains:

                   aecho=0.8:0.9:1000:0.3

       •   Same as above but with one more mountain:

                   aecho=0.8:0.9:1000|1800:0.3|0.25

   aemphasis
       Audio emphasis filter creates or restores material directly taken from LPs or emphased CDs with different filter curves.
       E.g. to store music on vinyl the signal has to be altered by a filter first to even out the disadvantages of this recording
       medium.  Once the material is played back the inverse filter has to be applied to restore the distortion of the frequency
       response.

       The filter accepts the following options:

       level_in
           Set input gain.

       level_out
           Set output gain.

       mode
           Set filter mode. For restoring material use "reproduction" mode, otherwise use "production" mode. Default is
           "reproduction" mode.

       type
           Set filter type. Selects medium. Can be one of the following:

           col select Columbia.

           emi select EMI.

           bsi select BSI (78RPM).

           riaa
               select RIAA.

           cd  select Compact Disc (CD).

           50fm
               select 50Xs (FM).

           75fm
               select 75Xs (FM).

           50kf
               select 50Xs (FM-KF).

           75kf
               select 75Xs (FM-KF).

       Commands

       This filter supports the all above options as commands.

   aeval
       Modify an audio signal according to the specified expressions.

       This filter accepts one or more expressions (one for each channel), which are evaluated and used to modify a corresponding
       audio signal.

       It accepts the following parameters:

       exprs
           Set the '|'-separated expressions list for each separate channel. If the number of input channels is greater than the
           number of expressions, the last specified expression is used for the remaining output channels.

       channel_layout, c
           Set output channel layout. If not specified, the channel layout is specified by the number of expressions. If set to
           same, it will use by default the same input channel layout.

       Each expression in exprs can contain the following constants and functions:

       ch  channel number of the current expression

       n   number of the evaluated sample, starting from 0

       s   sample rate

       t   time of the evaluated sample expressed in seconds

       nb_in_channels
       nb_out_channels
           input and output number of channels

       val(CH)
           the value of input channel with number CH

       Note: this filter is slow. For faster processing you should use a dedicated filter.

       Examples

       •   Half volume:

                   aeval=val(ch)/2:c=same

       •   Invert phase of the second channel:

                   aeval=val(0)|-val(1)

   aexciter
       An exciter is used to produce high sound that is not present in the original signal. This is done by creating harmonic
       distortions of the signal which are restricted in range and added to the original signal.  An Exciter raises the upper end
       of an audio signal without simply raising the higher frequencies like an equalizer would do to create a more "crisp" or
       "brilliant" sound.

       The filter accepts the following options:

       level_in
           Set input level prior processing of signal.  Allowed range is from 0 to 64.  Default value is 1.

       level_out
           Set output level after processing of signal.  Allowed range is from 0 to 64.  Default value is 1.

       amount
           Set the amount of harmonics added to original signal.  Allowed range is from 0 to 64.  Default value is 1.

       drive
           Set the amount of newly created harmonics.  Allowed range is from 0.1 to 10.  Default value is 8.5.

       blend
           Set the octave of newly created harmonics.  Allowed range is from -10 to 10.  Default value is 0.

       freq
           Set the lower frequency limit of producing harmonics in Hz.  Allowed range is from 2000 to 12000 Hz.  Default is 7500
           Hz.

       ceil
           Set the upper frequency limit of producing harmonics.  Allowed range is from 9999 to 20000 Hz.  If value is lower than
           10000 Hz no limit is applied.

       listen
           Mute the original signal and output only added harmonics.  By default is disabled.

       Commands

       This filter supports the all above options as commands.

   afade
       Apply fade-in/out effect to input audio.

       A description of the accepted parameters follows.

       type, t
           Specify the effect type, can be either "in" for fade-in, or "out" for a fade-out effect. Default is "in".

       start_sample, ss
           Specify the number of the start sample for starting to apply the fade effect. Default is 0.

       nb_samples, ns
           Specify the number of samples for which the fade effect has to last. At the end of the fade-in effect the output audio
           will have the same volume as the input audio, at the end of the fade-out transition the output audio will be silence.
           Default is 44100.

       start_time, st
           Specify the start time of the fade effect. Default is 0.  The value must be specified as a time duration; see the Time
           duration section in the ffmpeg-utils(1) manual for the accepted syntax.  If set this option is used instead of
           start_sample.

       duration, d
           Specify the duration of the fade effect. See the Time duration section in the ffmpeg-utils(1) manual for the accepted
           syntax.  At the end of the fade-in effect the output audio will have the same volume as the input audio, at the end of
           the fade-out transition the output audio will be silence.  By default the duration is determined by nb_samples.  If set
           this option is used instead of nb_samples.

       curve
           Set curve for fade transition.

           It accepts the following values:

           tri select triangular, linear slope (default)

           qsin
               select quarter of sine wave

           hsin
               select half of sine wave

           esin
               select exponential sine wave

           log select logarithmic

           ipar
               select inverted parabola

           qua select quadratic

           cub select cubic

           squ select square root

           cbr select cubic root

           par select parabola

           exp select exponential

           iqsin
               select inverted quarter of sine wave

           ihsin
               select inverted half of sine wave

           dese
               select double-exponential seat

           desi
               select double-exponential sigmoid

           losi
               select logistic sigmoid

           sinc
               select sine cardinal function

           isinc
               select inverted sine cardinal function

           nofade
               no fade applied

       Commands

       This filter supports the all above options as commands.

       Examples

       •   Fade in first 15 seconds of audio:

                   afade=t=in:ss=0:d=15

       •   Fade out last 25 seconds of a 900 seconds audio:

                   afade=t=out:st=875:d=25

   afftdn
       Denoise audio samples with FFT.

       A description of the accepted parameters follows.

       noise_reduction, nr
           Set the noise reduction in dB, allowed range is 0.01 to 97.  Default value is 12 dB.

       noise_floor, nf
           Set the noise floor in dB, allowed range is -80 to -20.  Default value is -50 dB.

       noise_type, nt
           Set the noise type.

           It accepts the following values:

           white, w
               Select white noise.

           vinyl, v
               Select vinyl noise.

           shellac, s
               Select shellac noise.

           custom, c
               Select custom noise, defined in "bn" option.

               Default value is white noise.

       band_noise, bn
           Set custom band noise profile for every one of 15 bands.  Bands are separated by ' ' or '|'.

       residual_floor, rf
           Set the residual floor in dB, allowed range is -80 to -20.  Default value is -38 dB.

       track_noise, tn
           Enable noise floor tracking. By default is disabled.  With this enabled, noise floor is automatically adjusted.

       track_residual, tr
           Enable residual tracking. By default is disabled.

       output_mode, om
           Set the output mode.

           It accepts the following values:

           input, i
               Pass input unchanged.

           output, o
               Pass noise filtered out.

           noise, n
               Pass only noise.

               Default value is output.

       adaptivity, ad
           Set the adaptivity factor, used how fast to adapt gains adjustments per each frequency bin. Value 0 enables instant
           adaptation, while higher values react much slower.  Allowed range is from 0 to 1. Default value is 0.5.

       floor_offset, fo
           Set the noise floor offset factor. This option is used to adjust offset applied to measured noise floor. It is only
           effective when noise floor tracking is enabled.  Allowed range is from -2.0 to 2.0. Default value is 1.0.

       noise_link, nl
           Set the noise link used for multichannel audio.

           It accepts the following values:

           none
               Use unchanged channel's noise floor.

           min Use measured min noise floor of all channels.

           max Use measured max noise floor of all channels.

           average
               Use measured average noise floor of all channels.

               Default value is min.

       band_multiplier, bm
           Set the band multiplier factor, used how much to spread bands across frequency bins.  Allowed range is from 0.2 to 5.
           Default value is 1.25.

       sample_noise, sn
           Toggle capturing and measurement of noise profile from input audio.

           It accepts the following values:

           start, begin
               Start sample noise capture.

           stop, end
               Stop sample noise capture and measure new noise band profile.

               Default value is "none".

       gain_smooth, gs
           Set gain smooth spatial radius, used to smooth gains applied to each frequency bin.  Useful to reduce random music noise
           artefacts.  Higher values increases smoothing of gains.  Allowed range is from 0 to 50.  Default value is 0.

       Commands

       This filter supports the some above mentioned options as commands.

       Examples

       •   Reduce white noise by 10dB, and use previously measured noise floor of -40dB:

                   afftdn=nr=10:nf=-40

       •   Reduce white noise by 10dB, also set initial noise floor to -80dB and enable automatic tracking of noise floor so noise
           floor will gradually change during processing:

                   afftdn=nr=10:nf=-80:tn=1

       •   Reduce noise by 20dB, using noise floor of -40dB and using commands to take noise profile of first 0.4 seconds of input
           audio:

                   asendcmd=0.0 afftdn sn start,asendcmd=0.4 afftdn sn stop,afftdn=nr=20:nf=-40

   afftfilt
       Apply arbitrary expressions to samples in frequency domain.

       real
           Set frequency domain real expression for each separate channel separated by '|'. Default is "re".  If the number of
           input channels is greater than the number of expressions, the last specified expression is used for the remaining output
           channels.

       imag
           Set frequency domain imaginary expression for each separate channel separated by '|'. Default is "im".

           Each expression in real and imag can contain the following constants and functions:

           sr  sample rate

           b   current frequency bin number

           nb  number of available bins

           ch  channel number of the current expression

           chs number of channels

           pts current frame pts

           re  current real part of frequency bin of current channel

           im  current imaginary part of frequency bin of current channel

           real(b, ch)
               Return the value of real part of frequency bin at location (bin,channel)

           imag(b, ch)
               Return the value of imaginary part of frequency bin at location (bin,channel)

       win_size
           Set window size. Allowed range is from 16 to 131072.  Default is 4096

       win_func
           Set window function.

           It accepts the following values:

           rect
           bartlett
           hann, hanning
           hamming
           blackman
           welch
           flattop
           bharris
           bnuttall
           bhann
           sine
           nuttall
           lanczos
           gauss
           tukey
           dolph
           cauchy
           parzen
           poisson
           bohman

           Default is "hann".

       overlap
           Set window overlap. If set to 1, the recommended overlap for selected window function will be picked. Default is 0.75.

       Examples

       •   Leave almost only low frequencies in audio:

                   afftfilt="'real=re * (1-clip((b/nb)*b,0,1))':imag='im * (1-clip((b/nb)*b,0,1))'"

       •   Apply robotize effect:

                   afftfilt="real='hypot(re,im)*sin(0)':imag='hypot(re,im)*cos(0)':win_size=512:overlap=0.75"

       •   Apply whisper effect:

                   afftfilt="real='hypot(re,im)*cos((random(0)*2-1)*2*3.14)':imag='hypot(re,im)*sin((random(1)*2-1)*2*3.14)':win_size=128:overlap=0.8"

   afir
       Apply an arbitrary Finite Impulse Response filter.

       This filter is designed for applying long FIR filters, up to 60 seconds long.

       It can be used as component for digital crossover filters, room equalization, cross talk cancellation, wavefield synthesis,
       auralization, ambiophonics, ambisonics and spatialization.

       This filter uses the streams higher than first one as FIR coefficients.  If the non-first stream holds a single channel, it
       will be used for all input channels in the first stream, otherwise the number of channels in the non-first stream must be
       same as the number of channels in the first stream.

       It accepts the following parameters:

       dry Set dry gain. This sets input gain.

       wet Set wet gain. This sets final output gain.

       length
           Set Impulse Response filter length. Default is 1, which means whole IR is processed.

       gtype
           Enable applying gain measured from power of IR.

           Set which approach to use for auto gain measurement.

           none
               Do not apply any gain.

           peak
               select peak gain, very conservative approach. This is default value.

           dc  select DC gain, limited application.

           gn  select gain to noise approach, this is most popular one.

       irgain
           Set gain to be applied to IR coefficients before filtering.  Allowed range is 0 to 1. This gain is applied after any
           gain applied with gtype option.

       irfmt
           Set format of IR stream. Can be "mono" or "input".  Default is "input".

       maxir
           Set max allowed Impulse Response filter duration in seconds. Default is 30 seconds.  Allowed range is 0.1 to 60 seconds.

       response
           Show IR frequency response, magnitude(magenta), phase(green) and group delay(yellow) in additional video stream.  By
           default it is disabled.

       channel
           Set for which IR channel to display frequency response. By default is first channel displayed. This option is used only
           when response is enabled.

       size
           Set video stream size. This option is used only when response is enabled.

       rate
           Set video stream frame rate. This option is used only when response is enabled.

       minp
           Set minimal partition size used for convolution. Default is 8192.  Allowed range is from 1 to 32768.  Lower values
           decreases latency at cost of higher CPU usage.

       maxp
           Set maximal partition size used for convolution. Default is 8192.  Allowed range is from 8 to 32768.  Lower values may
           increase CPU usage.

       nbirs
           Set number of input impulse responses streams which will be switchable at runtime.  Allowed range is from 1 to 32.
           Default is 1.

       ir  Set IR stream which will be used for convolution, starting from 0, should always be lower than supplied value by "nbirs"
           option. Default is 0.  This option can be changed at runtime via commands.

       precision
           Set which precision to use when processing samples.

           auto
               Auto pick internal sample format depending on other filters.

           float
               Always use single-floating point precision sample format.

           double
               Always use double-floating point precision sample format.

           Default value is auto.

       Examples

       •   Apply reverb to stream using mono IR file as second input, complete command using ffmpeg:

                   ffmpeg -i input.wav -i middle_tunnel_1way_mono.wav -lavfi afir output.wav

   aformat
       Set output format constraints for the input audio. The framework will negotiate the most appropriate format to minimize
       conversions.

       It accepts the following parameters:

       sample_fmts, f
           A '|'-separated list of requested sample formats.

       sample_rates, r
           A '|'-separated list of requested sample rates.

       channel_layouts, cl
           A '|'-separated list of requested channel layouts.

           See the Channel Layout section in the ffmpeg-utils(1) manual for the required syntax.

       If a parameter is omitted, all values are allowed.

       Force the output to either unsigned 8-bit or signed 16-bit stereo

               aformat=sample_fmts=u8|s16:channel_layouts=stereo

   afreqshift
       Apply frequency shift to input audio samples.

       The filter accepts the following options:

       shift
           Specify frequency shift. Allowed range is -INT_MAX to INT_MAX.  Default value is 0.0.

       level
           Set output gain applied to final output. Allowed range is from 0.0 to 1.0.  Default value is 1.0.

       order
           Set filter order used for filtering. Allowed range is from 1 to 16.  Default value is 8.

       Commands

       This filter supports the all above options as commands.

   afwtdn
       Reduce broadband noise from input samples using Wavelets.

       A description of the accepted options follows.

       sigma
           Set the noise sigma, allowed range is from 0 to 1.  Default value is 0.  This option controls strength of denoising
           applied to input samples.  Most useful way to set this option is via decibels, eg. -45dB.

       levels
           Set the number of wavelet levels of decomposition.  Allowed range is from 1 to 12.  Default value is 10.  Setting this
           too low make denoising performance very poor.

       wavet
           Set wavelet type for decomposition of input frame.  They are sorted by number of coefficients, from lowest to highest.
           More coefficients means worse filtering speed, but overall better quality.  Available wavelets are:

           sym2
           sym4
           rbior68
           deb10
           sym10
           coif5
           bl3
       percent
           Set percent of full denoising. Allowed range is from 0 to 100 percent.  Default value is 85 percent or partial
           denoising.

       profile
           If enabled, first input frame will be used as noise profile.  If first frame samples contain non-noise performance will
           be very poor.

       adaptive
           If enabled, input frames are analyzed for presence of noise.  If noise is detected with high possibility then input
           frame profile will be used for processing following frames, until new noise frame is detected.

       samples
           Set size of single frame in number of samples. Allowed range is from 512 to 65536. Default frame size is 8192 samples.

       softness
           Set softness applied inside thresholding function. Allowed range is from 0 to 10. Default softness is 1.

       Commands

       This filter supports the all above options as commands.

   agate
       A gate is mainly used to reduce lower parts of a signal. This kind of signal processing reduces disturbing noise between
       useful signals.

       Gating is done by detecting the volume below a chosen level threshold and dividing it by the factor set with ratio. The
       bottom of the noise floor is set via range. Because an exact manipulation of the signal would cause distortion of the
       waveform the reduction can be levelled over time. This is done by setting attack and release.

       attack determines how long the signal has to fall below the threshold before any reduction will occur and release sets the
       time the signal has to rise above the threshold to reduce the reduction again.  Shorter signals than the chosen attack time
       will be left untouched.

       level_in
           Set input level before filtering.  Default is 1. Allowed range is from 0.015625 to 64.

       mode
           Set the mode of operation. Can be "upward" or "downward".  Default is "downward". If set to "upward" mode, higher parts
           of signal will be amplified, expanding dynamic range in upward direction.  Otherwise, in case of "downward" lower parts
           of signal will be reduced.

       range
           Set the level of gain reduction when the signal is below the threshold.  Default is 0.06125. Allowed range is from 0 to
           1.  Setting this to 0 disables reduction and then filter behaves like expander.

       threshold
           If a signal rises above this level the gain reduction is released.  Default is 0.125. Allowed range is from 0 to 1.

       ratio
           Set a ratio by which the signal is reduced.  Default is 2. Allowed range is from 1 to 9000.

       attack
           Amount of milliseconds the signal has to rise above the threshold before gain reduction stops.  Default is 20
           milliseconds. Allowed range is from 0.01 to 9000.

       release
           Amount of milliseconds the signal has to fall below the threshold before the reduction is increased again. Default is
           250 milliseconds.  Allowed range is from 0.01 to 9000.

       makeup
           Set amount of amplification of signal after processing.  Default is 1. Allowed range is from 1 to 64.

       knee
           Curve the sharp knee around the threshold to enter gain reduction more softly.  Default is 2.828427125. Allowed range is
           from 1 to 8.

       detection
           Choose if exact signal should be taken for detection or an RMS like one.  Default is "rms". Can be "peak" or "rms".

       link
           Choose if the average level between all channels or the louder channel affects the reduction.  Default is "average". Can
           be "average" or "maximum".

       Commands

       This filter supports the all above options as commands.

   aiir
       Apply an arbitrary Infinite Impulse Response filter.

       It accepts the following parameters:

       zeros, z
           Set B/numerator/zeros/reflection coefficients.

       poles, p
           Set A/denominator/poles/ladder coefficients.

       gains, k
           Set channels gains.

       dry_gain
           Set input gain.

       wet_gain
           Set output gain.

       format, f
           Set coefficients format.

           ll  lattice-ladder function

           sf  analog transfer function

           tf  digital transfer function

           zp  Z-plane zeros/poles, cartesian (default)

           pr  Z-plane zeros/poles, polar radians

           pd  Z-plane zeros/poles, polar degrees

           sp  S-plane zeros/poles

       process, r
           Set type of processing.

           d   direct processing

           s   serial processing

           p   parallel processing

       precision, e
           Set filtering precision.

           dbl double-precision floating-point (default)

           flt single-precision floating-point

           i32 32-bit integers

           i16 16-bit integers

       normalize, n
           Normalize filter coefficients, by default is enabled.  Enabling it will normalize magnitude response at DC to 0dB.

       mix How much to use filtered signal in output. Default is 1.  Range is between 0 and 1.

       response
           Show IR frequency response, magnitude(magenta), phase(green) and group delay(yellow) in additional video stream.  By
           default it is disabled.

       channel
           Set for which IR channel to display frequency response. By default is first channel displayed. This option is used only
           when response is enabled.

       size
           Set video stream size. This option is used only when response is enabled.

       Coefficients in "tf" and "sf" format are separated by spaces and are in ascending order.

       Coefficients in "zp" format are separated by spaces and order of coefficients doesn't matter. Coefficients in "zp" format
       are complex numbers with i imaginary unit.

       Different coefficients and gains can be provided for every channel, in such case use '|' to separate coefficients or gains.
       Last provided coefficients will be used for all remaining channels.

       Examples

       •   Apply 2 pole elliptic notch at around 5000Hz for 48000 Hz sample rate:

                   aiir=k=1:z=7.957584807809675810E-1 -2.575128568908332300 3.674839853930788710 -2.57512875289799137 7.957586296317130880E-1:p=1 -2.86950072432325953 3.63022088054647218 -2.28075678147272232 6.361362326477423500E-1:f=tf:r=d

       •   Same as above but in "zp" format:

                   aiir=k=0.79575848078096756:z=0.80918701+0.58773007i 0.80918701-0.58773007i 0.80884700+0.58784055i 0.80884700-0.58784055i:p=0.63892345+0.59951235i 0.63892345-0.59951235i 0.79582691+0.44198673i 0.79582691-0.44198673i:f=zp:r=s

       •   Apply 3-rd order analog normalized Butterworth low-pass filter, using analog transfer function format:

                   aiir=z=1.3057 0 0 0:p=1.3057 2.3892 2.1860 1:f=sf:r=d

   alimiter
       The limiter prevents an input signal from rising over a desired threshold.  This limiter uses lookahead technology to
       prevent your signal from distorting.  It means that there is a small delay after the signal is processed. Keep in mind that
       the delay it produces is the attack time you set.

       The filter accepts the following options:

       level_in
           Set input gain. Default is 1.

       level_out
           Set output gain. Default is 1.

       limit
           Don't let signals above this level pass the limiter. Default is 1.

       attack
           The limiter will reach its attenuation level in this amount of time in milliseconds. Default is 5 milliseconds.

       release
           Come back from limiting to attenuation 1.0 in this amount of milliseconds.  Default is 50 milliseconds.

       asc When gain reduction is always needed ASC takes care of releasing to an average reduction level rather than reaching a
           reduction of 0 in the release time.

       asc_level
           Select how much the release time is affected by ASC, 0 means nearly no changes in release time while 1 produces higher
           release times.

       level
           Auto level output signal. Default is enabled.  This normalizes audio back to 0dB if enabled.

       latency
           Compensate the delay introduced by using the lookahead buffer set with attack parameter. Also flush the valid audio data
           in the lookahead buffer when the stream hits EOF.

       Depending on picked setting it is recommended to upsample input 2x or 4x times with aresample before applying this filter.

   allpass
       Apply a two-pole all-pass filter with central frequency (in Hz) frequency, and filter-width width.  An all-pass filter
       changes the audio's frequency to phase relationship without changing its frequency to amplitude relationship.

       The filter accepts the following options:

       frequency, f
           Set frequency in Hz.

       width_type, t
           Set method to specify band-width of filter.

           h   Hz

           q   Q-Factor

           o   octave

           s   slope

           k   kHz

       width, w
           Specify the band-width of a filter in width_type units.

       mix, m
           How much to use filtered signal in output. Default is 1.  Range is between 0 and 1.

       channels, c
           Specify which channels to filter, by default all available are filtered.

       normalize, n
           Normalize biquad coefficients, by default is disabled.  Enabling it will normalize magnitude response at DC to 0dB.

       order, o
           Set the filter order, can be 1 or 2. Default is 2.

       transform, a
           Set transform type of IIR filter.

           di
           dii
           tdi
           tdii
           latt
           svf
           zdf
       precision, r
           Set precison of filtering.

           auto
               Pick automatic sample format depending on surround filters.

           s16 Always use signed 16-bit.

           s32 Always use signed 32-bit.

           f32 Always use float 32-bit.

           f64 Always use float 64-bit.

       Commands

       This filter supports the following commands:

       frequency, f
           Change allpass frequency.  Syntax for the command is : "frequency"

       width_type, t
           Change allpass width_type.  Syntax for the command is : "width_type"

       width, w
           Change allpass width.  Syntax for the command is : "width"

       mix, m
           Change allpass mix.  Syntax for the command is : "mix"

   aloop
       Loop audio samples.

       The filter accepts the following options:

       loop
           Set the number of loops. Setting this value to -1 will result in infinite loops.  Default is 0.

       size
           Set maximal number of samples. Default is 0.

       start
           Set first sample of loop. Default is 0.

   amerge
       Merge two or more audio streams into a single multi-channel stream.

       The filter accepts the following options:

       inputs
           Set the number of inputs. Default is 2.

       If the channel layouts of the inputs are disjoint, and therefore compatible, the channel layout of the output will be set
       accordingly and the channels will be reordered as necessary. If the channel layouts of the inputs are not disjoint, the
       output will have all the channels of the first input then all the channels of the second input, in that order, and the
       channel layout of the output will be the default value corresponding to the total number of channels.

       For example, if the first input is in 2.1 (FL+FR+LF) and the second input is FC+BL+BR, then the output will be in 5.1, with
       the channels in the following order: a1, a2, b1, a3, b2, b3 (a1 is the first channel of the first input, b1 is the first
       channel of the second input).

       On the other hand, if both input are in stereo, the output channels will be in the default order: a1, a2, b1, b2, and the
       channel layout will be arbitrarily set to 4.0, which may or may not be the expected value.

       All inputs must have the same sample rate, and format.

       If inputs do not have the same duration, the output will stop with the shortest.

       Examples

       •   Merge two mono files into a stereo stream:

                   amovie=left.wav [l] ; amovie=right.mp3 [r] ; [l] [r] amerge

       •   Multiple merges assuming 1 video stream and 6 audio streams in input.mkv:

                   ffmpeg -i input.mkv -filter_complex "[0:1][0:2][0:3][0:4][0:5][0:6] amerge=inputs=6" -c:a pcm_s16le output.mkv

   amix
       Mixes multiple audio inputs into a single output.

       Note that this filter only supports float samples (the amerge and pan audio filters support many formats). If the amix input
       has integer samples then aresample will be automatically inserted to perform the conversion to float samples.

       For example

               ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 OUTPUT

       will mix 3 input audio streams to a single output with the same duration as the first input and a dropout transition time of
       3 seconds.

       It accepts the following parameters:

       inputs
           The number of inputs. If unspecified, it defaults to 2.

       duration
           How to determine the end-of-stream.

           longest
               The duration of the longest input. (default)

           shortest
               The duration of the shortest input.

           first
               The duration of the first input.

       dropout_transition
           The transition time, in seconds, for volume renormalization when an input stream ends. The default value is 2 seconds.

       weights
           Specify weight of each input audio stream as sequence.  Each weight is separated by space. By default all inputs have
           same weight.

       normalize
           Always scale inputs instead of only doing summation of samples.  Beware of heavy clipping if inputs are not normalized
           prior or after filtering by this filter if this option is disabled. By default is enabled.

       Commands

       This filter supports the following commands:

       weights
       normalize
           Syntax is same as option with same name.

   amultiply
       Multiply first audio stream with second audio stream and store result in output audio stream. Multiplication is done by
       multiplying each sample from first stream with sample at same position from second stream.

       With this element-wise multiplication one can create amplitude fades and amplitude modulations.

   anequalizer
       High-order parametric multiband equalizer for each channel.

       It accepts the following parameters:

       params
           This option string is in format: "cchn f=cf w=w g=g t=f | ..."  Each equalizer band is separated by '|'.

           chn Set channel number to which equalization will be applied.  If input doesn't have that channel the entry is ignored.

           f   Set central frequency for band.  If input doesn't have that frequency the entry is ignored.

           w   Set band width in Hertz.

           g   Set band gain in dB.

           t   Set filter type for band, optional, can be:

               0   Butterworth, this is default.

               1   Chebyshev type 1.

               2   Chebyshev type 2.

       curves
           With this option activated frequency response of anequalizer is displayed in video stream.

       size
           Set video stream size. Only useful if curves option is activated.

       mgain
           Set max gain that will be displayed. Only useful if curves option is activated.  Setting this to a reasonable value
           makes it possible to display gain which is derived from neighbour bands which are too close to each other and thus
           produce higher gain when both are activated.

       fscale
           Set frequency scale used to draw frequency response in video output.  Can be linear or logarithmic. Default is
           logarithmic.

       colors
           Set color for each channel curve which is going to be displayed in video stream.  This is list of color names separated
           by space or by '|'.  Unrecognised or missing colors will be replaced by white color.

       Examples

       •   Lower gain by 10 of central frequency 200Hz and width 100 Hz for first 2 channels using Chebyshev type 1 filter:

                   anequalizer=c0 f=200 w=100 g=-10 t=1|c1 f=200 w=100 g=-10 t=1

       Commands

       This filter supports the following commands:

       change
           Alter existing filter parameters.  Syntax for the commands is : "fN|f=freq|w=width|g=gain"

           fN is existing filter number, starting from 0, if no such filter is available error is returned.  freq set new frequency
           parameter.  width set new width parameter in Hertz.  gain set new gain parameter in dB.

           Full filter invocation with asendcmd may look like this: asendcmd=c='4.0 anequalizer change
           0|f=200|w=50|g=1',anequalizer=...

   anlmdn
       Reduce broadband noise in audio samples using Non-Local Means algorithm.

       Each sample is adjusted by looking for other samples with similar contexts. This context similarity is defined by comparing
       their surrounding patches of size p. Patches are searched in an area of r around the sample.

       The filter accepts the following options:

       strength, s
           Set denoising strength. Allowed range is from 0.00001 to 10000. Default value is 0.00001.

       patch, p
           Set patch radius duration. Allowed range is from 1 to 100 milliseconds.  Default value is 2 milliseconds.

       research, r
           Set research radius duration. Allowed range is from 2 to 300 milliseconds.  Default value is 6 milliseconds.

       output, o
           Set the output mode.

           It accepts the following values:

           i   Pass input unchanged.

           o   Pass noise filtered out.

           n   Pass only noise.

               Default value is o.

       smooth, m
           Set smooth factor. Default value is 11. Allowed range is from 1 to 1000.

       Commands

       This filter supports the all above options as commands.

   anlmf, anlms
       Apply Normalized Least-Mean-(Squares|Fourth) algorithm to the first audio stream using the second audio stream.

       This adaptive filter is used to mimic a desired filter by finding the filter coefficients that relate to producing the least
       mean square of the error signal (difference between the desired, 2nd input audio stream and the actual signal, the 1st input
       audio stream).

       A description of the accepted options follows.

       order
           Set filter order.

       mu  Set filter mu.

       eps Set the filter eps.

       leakage
           Set the filter leakage.

       out_mode
           It accepts the following values:

           i   Pass the 1st input.

           d   Pass the 2nd input.

           o   Pass filtered samples.

           n   Pass difference between desired and filtered samples.

               Default value is o.

       Examples

       •   One of many usages of this filter is noise reduction, input audio is filtered with same samples that are delayed by
           fixed amount, one such example for stereo audio is:

                   asplit[a][b],[a]adelay=32S|32S[a],[b][a]anlms=order=128:leakage=0.0005:mu=.5:out_mode=o

       Commands

       This filter supports the same commands as options, excluding option "order".

   anull
       Pass the audio source unchanged to the output.

   apad
       Pad the end of an audio stream with silence.

       This can be used together with ffmpeg -shortest to extend audio streams to the same length as the video stream.

       A description of the accepted options follows.

       packet_size
           Set silence packet size. Default value is 4096.

       pad_len
           Set the number of samples of silence to add to the end. After the value is reached, the stream is terminated. This
           option is mutually exclusive with whole_len.

       whole_len
           Set the minimum total number of samples in the output audio stream. If the value is longer than the input audio length,
           silence is added to the end, until the value is reached. This option is mutually exclusive with pad_len.

       pad_dur
           Specify the duration of samples of silence to add. See the Time duration section in the ffmpeg-utils(1) manual for the
           accepted syntax. Used only if set to non-negative value.

       whole_dur
           Specify the minimum total duration in the output audio stream. See the Time duration section in the ffmpeg-utils(1)
           manual for the accepted syntax. Used only if set to non-negative value. If the value is longer than the input audio
           length, silence is added to the end, until the value is reached.  This option is mutually exclusive with pad_dur

       If neither the pad_len nor the whole_len nor pad_dur nor whole_dur option is set, the filter will add silence to the end of
       the input stream indefinitely.

       Note that for ffmpeg 4.4 and earlier a zero pad_dur or whole_dur also caused the filter to add silence indefinitely.

       Examples

       •   Add 1024 samples of silence to the end of the input:

                   apad=pad_len=1024

       •   Make sure the audio output will contain at least 10000 samples, pad the input with silence if required:

                   apad=whole_len=10000

       •   Use ffmpeg to pad the audio input with silence, so that the video stream will always result the shortest and will be
           converted until the end in the output file when using the shortest option:

                   ffmpeg -i VIDEO -i AUDIO -filter_complex "[1:0]apad" -shortest OUTPUT

   aphaser
       Add a phasing effect to the input audio.

       A phaser filter creates series of peaks and troughs in the frequency spectrum.  The position of the peaks and troughs are
       modulated so that they vary over time, creating a sweeping effect.

       A description of the accepted parameters follows.

       in_gain
           Set input gain. Default is 0.4.

       out_gain
           Set output gain. Default is 0.74

       delay
           Set delay in milliseconds. Default is 3.0.

       decay
           Set decay. Default is 0.4.

       speed
           Set modulation speed in Hz. Default is 0.5.

       type
           Set modulation type. Default is triangular.

           It accepts the following values:

           triangular, t
           sinusoidal, s

   aphaseshift
       Apply phase shift to input audio samples.

       The filter accepts the following options:

       shift
           Specify phase shift. Allowed range is from -1.0 to 1.0.  Default value is 0.0.

       level
           Set output gain applied to final output. Allowed range is from 0.0 to 1.0.  Default value is 1.0.

       order
           Set filter order used for filtering. Allowed range is from 1 to 16.  Default value is 8.

       Commands

       This filter supports the all above options as commands.

   apsyclip
       Apply Psychoacoustic clipper to input audio stream.

       The filter accepts the following options:

       level_in
           Set input gain. By default it is 1. Range is [0.015625 - 64].

       level_out
           Set output gain. By default it is 1. Range is [0.015625 - 64].

       clip
           Set the clipping start value. Default value is 0dBFS or 1.

       diff
           Output only difference samples, useful to hear introduced distortions.  By default is disabled.

       adaptive
           Set strength of adaptive distortion applied. Default value is 0.5.  Allowed range is from 0 to 1.

       iterations
           Set number of iterations of psychoacoustic clipper.  Allowed range is from 1 to 20. Default value is 10.

       level
           Auto level output signal. Default is disabled.  This normalizes audio back to 0dBFS if enabled.

       Commands

       This filter supports the all above options as commands.

   apulsator
       Audio pulsator is something between an autopanner and a tremolo.  But it can produce funny stereo effects as well. Pulsator
       changes the volume of the left and right channel based on a LFO (low frequency oscillator) with different waveforms and
       shifted phases.  This filter have the ability to define an offset between left and right channel. An offset of 0 means that
       both LFO shapes match each other.  The left and right channel are altered equally - a conventional tremolo.  An offset of
       50% means that the shape of the right channel is exactly shifted in phase (or moved backwards about half of the frequency) -
       pulsator acts as an autopanner. At 1 both curves match again. Every setting in between moves the phase shift gapless between
       all stages and produces some "bypassing" sounds with sine and triangle waveforms. The more you set the offset near 1
       (starting from the 0.5) the faster the signal passes from the left to the right speaker.

       The filter accepts the following options:

       level_in
           Set input gain. By default it is 1. Range is [0.015625 - 64].

       level_out
           Set output gain. By default it is 1. Range is [0.015625 - 64].

       mode
           Set waveform shape the LFO will use. Can be one of: sine, triangle, square, sawup or sawdown. Default is sine.

       amount
           Set modulation. Define how much of original signal is affected by the LFO.

       offset_l
           Set left channel offset. Default is 0. Allowed range is [0 - 1].

       offset_r
           Set right channel offset. Default is 0.5. Allowed range is [0 - 1].

       width
           Set pulse width. Default is 1. Allowed range is [0 - 2].

       timing
           Set possible timing mode. Can be one of: bpm, ms or hz. Default is hz.

       bpm Set bpm. Default is 120. Allowed range is [30 - 300]. Only used if timing is set to bpm.

       ms  Set ms. Default is 500. Allowed range is [10 - 2000]. Only used if timing is set to ms.

       hz  Set frequency in Hz. Default is 2. Allowed range is [0.01 - 100]. Only used if timing is set to hz.

   aresample
       Resample the input audio to the specified parameters, using the libswresample library. If none are specified then the filter
       will automatically convert between its input and output.

       This filter is also able to stretch/squeeze the audio data to make it match the timestamps or to inject silence / cut out
       audio to make it match the timestamps, do a combination of both or do neither.

       The filter accepts the syntax [sample_rate:]resampler_options, where sample_rate expresses a sample rate and
       resampler_options is a list of key=value pairs, separated by ":". See the "Resampler Options" section in the
       ffmpeg-resampler(1) manual for the complete list of supported options.

       Examples

       •   Resample the input audio to 44100Hz:

                   aresample=44100

       •   Stretch/squeeze samples to the given timestamps, with a maximum of 1000 samples per second compensation:

                   aresample=async=1000

   areverse
       Reverse an audio clip.

       Warning: This filter requires memory to buffer the entire clip, so trimming is suggested.

       Examples

       •   Take the first 5 seconds of a clip, and reverse it.

                   atrim=end=5,areverse

   arnndn
       Reduce noise from speech using Recurrent Neural Networks.

       This filter accepts the following options:

       model, m
           Set train model file to load. This option is always required.

       mix Set how much to mix filtered samples into final output.  Allowed range is from -1 to 1. Default value is 1.  Negative
           values are special, they set how much to keep filtered noise in the final filter output. Set this option to -1 to hear
           actual noise removed from input signal.

       Commands

       This filter supports the all above options as commands.

   asdr
       Measure Audio Signal-to-Distortion Ratio.

       This filter takes two audio streams for input, and outputs first audio stream.  Results are in dB per channel at end of
       either input.

   asetnsamples
       Set the number of samples per each output audio frame.

       The last output packet may contain a different number of samples, as the filter will flush all the remaining samples when
       the input audio signals its end.

       The filter accepts the following options:

       nb_out_samples, n
           Set the number of frames per each output audio frame. The number is intended as the number of samples per each channel.
           Default value is 1024.

       pad, p
           If set to 1, the filter will pad the last audio frame with zeroes, so that the last frame will contain the same number
           of samples as the previous ones. Default value is 1.

       For example, to set the number of per-frame samples to 1234 and disable padding for the last frame, use:

               asetnsamples=n=1234:p=0

   asetrate
       Set the sample rate without altering the PCM data.  This will result in a change of speed and pitch.

       The filter accepts the following options:

       sample_rate, r
           Set the output sample rate. Default is 44100 Hz.

   ashowinfo
       Show a line containing various information for each input audio frame.  The input audio is not modified.

       The shown line contains a sequence of key/value pairs of the form key:value.

       The following values are shown in the output:

       n   The (sequential) number of the input frame, starting from 0.

       pts The presentation timestamp of the input frame, in time base units; the time base depends on the filter input pad, and is
           usually 1/sample_rate.

       pts_time
           The presentation timestamp of the input frame in seconds.

       pos position of the frame in the input stream, -1 if this information in unavailable and/or meaningless (for example in case
           of synthetic audio)

       fmt The sample format.

       chlayout
           The channel layout.

       rate
           The sample rate for the audio frame.

       nb_samples
           The number of samples (per channel) in the frame.

       checksum
           The Adler-32 checksum (printed in hexadecimal) of the audio data. For planar audio, the data is treated as if all the
           planes were concatenated.

       plane_checksums
           A list of Adler-32 checksums for each data plane.

   asoftclip
       Apply audio soft clipping.

       Soft clipping is a type of distortion effect where the amplitude of a signal is saturated along a smooth curve, rather than
       the abrupt shape of hard-clipping.

       This filter accepts the following options:

       type
           Set type of soft-clipping.

           It accepts the following values:

           hard
           tanh
           atan
           cubic
           exp
           alg
           quintic
           sin
           erf
       threshold
           Set threshold from where to start clipping. Default value is 0dB or 1.

       output
           Set gain applied to output. Default value is 0dB or 1.

       param
           Set additional parameter which controls sigmoid function.

       oversample
           Set oversampling factor.

       Commands

       This filter supports the all above options as commands.

   aspectralstats
       Display frequency domain statistical information about the audio channels.  Statistics are calculated and stored as metadata
       for each audio channel and for each audio frame.

       It accepts the following option:

       win_size
           Set the window length in samples. Default value is 2048.  Allowed range is from 32 to 65536.

       win_func
           Set window function.

           It accepts the following values:

           rect
           bartlett
           hann, hanning
           hamming
           blackman
           welch
           flattop
           bharris
           bnuttall
           bhann
           sine
           nuttall
           lanczos
           gauss
           tukey
           dolph
           cauchy
           parzen
           poisson
           bohman

           Default is "hann".

       overlap
           Set window overlap. Allowed range is from 0 to 1. Default value is 0.5.

       A list of each metadata key follows:

       mean
       variance
       centroid
       spread
       skewness
       kurtosis
       entropy
       flatness
       crest
       flux
       slope
       decrease
       rolloff

   asr
       Automatic Speech Recognition

       This filter uses PocketSphinx for speech recognition. To enable compilation of this filter, you need to configure FFmpeg
       with "--enable-pocketsphinx".

       It accepts the following options:

       rate
           Set sampling rate of input audio. Defaults is 16000.  This need to match speech models, otherwise one will get poor
           results.

       hmm Set dictionary containing acoustic model files.

       dict
           Set pronunciation dictionary.

       lm  Set language model file.

       lmctl
           Set language model set.

       lmname
           Set which language model to use.

       logfn
           Set output for log messages.

       The filter exports recognized speech as the frame metadata "lavfi.asr.text".

   astats
       Display time domain statistical information about the audio channels.  Statistics are calculated and displayed for each
       audio channel and, where applicable, an overall figure is also given.

       It accepts the following option:

       length
           Short window length in seconds, used for peak and trough RMS measurement.  Default is 0.05 (50 milliseconds). Allowed
           range is "[0 - 10]".

       metadata
           Set metadata injection. All the metadata keys are prefixed with "lavfi.astats.X", where "X" is channel number starting
           from 1 or string "Overall". Default is disabled.

           Available keys for each channel are: DC_offset Min_level Max_level Min_difference Max_difference Mean_difference
           RMS_difference Peak_level RMS_peak RMS_trough Crest_factor Flat_factor Peak_count Noise_floor Noise_floor_count Entropy
           Bit_depth Dynamic_range Zero_crossings Zero_crossings_rate Number_of_NaNs Number_of_Infs Number_of_denormals

           and for Overall: DC_offset Min_level Max_level Min_difference Max_difference Mean_difference RMS_difference Peak_level
           RMS_level RMS_peak RMS_trough Flat_factor Peak_count Noise_floor Noise_floor_count Entropy Bit_depth Number_of_samples
           Number_of_NaNs Number_of_Infs Number_of_denormals

           For example full key look like this "lavfi.astats.1.DC_offset" or this "lavfi.astats.Overall.Peak_count".

           For description what each key means read below.

       reset
           Set the number of frames over which cumulative stats are calculated before being reset Default is disabled.

       measure_perchannel
           Select the parameters which are measured per channel. The metadata keys can be used as flags, default is all which
           measures everything.  none disables all per channel measurement.

       measure_overall
           Select the parameters which are measured overall. The metadata keys can be used as flags, default is all which measures
           everything.  none disables all overall measurement.

       A description of each shown parameter follows:

       DC offset
           Mean amplitude displacement from zero.

       Min level
           Minimal sample level.

       Max level
           Maximal sample level.

       Min difference
           Minimal difference between two consecutive samples.

       Max difference
           Maximal difference between two consecutive samples.

       Mean difference
           Mean difference between two consecutive samples.  The average of each difference between two consecutive samples.

       RMS difference
           Root Mean Square difference between two consecutive samples.

       Peak level dB
       RMS level dB
           Standard peak and RMS level measured in dBFS.

       RMS peak dB
       RMS trough dB
           Peak and trough values for RMS level measured over a short window.

       Crest factor
           Standard ratio of peak to RMS level (note: not in dB).

       Flat factor
           Flatness (i.e. consecutive samples with the same value) of the signal at its peak levels (i.e. either Min level or Max
           level).

       Peak count
           Number of occasions (not the number of samples) that the signal attained either Min level or Max level.

       Noise floor dB
           Minimum local peak measured in dBFS over a short window.

       Noise floor count
           Number of occasions (not the number of samples) that the signal attained Noise floor.

       Entropy
           Entropy measured across whole audio. Entropy of value near 1.0 is typically measured for white noise.

       Bit depth
           Overall bit depth of audio. Number of bits used for each sample.

       Dynamic range
           Measured dynamic range of audio in dB.

       Zero crossings
           Number of points where the waveform crosses the zero level axis.

       Zero crossings rate
           Rate of Zero crossings and number of audio samples.

   asubboost
       Boost subwoofer frequencies.

       The filter accepts the following options:

       dry Set dry gain, how much of original signal is kept. Allowed range is from 0 to 1.  Default value is 1.0.

       wet Set wet gain, how much of filtered signal is kept. Allowed range is from 0 to 1.  Default value is 1.0.

       boost
           Set max boost factor. Allowed range is from 1 to 12. Default value is 2.

       decay
           Set delay line decay gain value. Allowed range is from 0 to 1.  Default value is 0.0.

       feedback
           Set delay line feedback gain value. Allowed range is from 0 to 1.  Default value is 0.9.

       cutoff
           Set cutoff frequency in Hertz. Allowed range is 50 to 900.  Default value is 100.

       slope
           Set slope amount for cutoff frequency. Allowed range is 0.0001 to 1.  Default value is 0.5.

       delay
           Set delay. Allowed range is from 1 to 100.  Default value is 20.

       channels
           Set the channels to process. Default value is all available.

       Commands

       This filter supports the all above options as commands.

   asubcut
       Cut subwoofer frequencies.

       This filter allows to set custom, steeper roll off than highpass filter, and thus is able to more attenuate frequency
       content in stop-band.

       The filter accepts the following options:

       cutoff
           Set cutoff frequency in Hertz. Allowed range is 2 to 200.  Default value is 20.

       order
           Set filter order. Available values are from 3 to 20.  Default value is 10.

       level
           Set input gain level. Allowed range is from 0 to 1. Default value is 1.

       Commands

       This filter supports the all above options as commands.

   asupercut
       Cut super frequencies.

       The filter accepts the following options:

       cutoff
           Set cutoff frequency in Hertz. Allowed range is 20000 to 192000.  Default value is 20000.

       order
           Set filter order. Available values are from 3 to 20.  Default value is 10.

       level
           Set input gain level. Allowed range is from 0 to 1. Default value is 1.

       Commands

       This filter supports the all above options as commands.

   asuperpass
       Apply high order Butterworth band-pass filter.

       The filter accepts the following options:

       centerf
           Set center frequency in Hertz. Allowed range is 2 to 999999.  Default value is 1000.

       order
           Set filter order. Available values are from 4 to 20.  Default value is 4.

       qfactor
           Set Q-factor. Allowed range is from 0.01 to 100. Default value is 1.

       level
           Set input gain level. Allowed range is from 0 to 2. Default value is 1.

       Commands

       This filter supports the all above options as commands.

   asuperstop
       Apply high order Butterworth band-stop filter.

       The filter accepts the following options:

       centerf
           Set center frequency in Hertz. Allowed range is 2 to 999999.  Default value is 1000.

       order
           Set filter order. Available values are from 4 to 20.  Default value is 4.

       qfactor
           Set Q-factor. Allowed range is from 0.01 to 100. Default value is 1.

       level
           Set input gain level. Allowed range is from 0 to 2. Default value is 1.

       Commands

       This filter supports the all above options as commands.

   atempo
       Adjust audio tempo.

       The filter accepts exactly one parameter, the audio tempo. If not specified then the filter will assume nominal 1.0 tempo.
       Tempo must be in the [0.5, 100.0] range.

       Note that tempo greater than 2 will skip some samples rather than blend them in.  If for any reason this is a concern it is
       always possible to daisy-chain several instances of atempo to achieve the desired product tempo.

       Examples

       •   Slow down audio to 80% tempo:

                   atempo=0.8

       •   To speed up audio to 300% tempo:

                   atempo=3

       •   To speed up audio to 300% tempo by daisy-chaining two atempo instances:

                   atempo=sqrt(3),atempo=sqrt(3)

       Commands

       This filter supports the following commands:

       tempo
           Change filter tempo scale factor.  Syntax for the command is : "tempo"

   atilt
       Apply spectral tilt filter to audio stream.

       This filter apply any spectral roll-off slope over any specified frequency band.

       The filter accepts the following options:

       freq
           Set central frequency of tilt in Hz. Default is 10000 Hz.

       slope
           Set slope direction of tilt. Default is 0. Allowed range is from -1 to 1.

       width
           Set width of tilt. Default is 1000. Allowed range is from 100 to 10000.

       order
           Set order of tilt filter.

       level
           Set input volume level. Allowed range is from 0 to 4.  Defalt is 1.

       Commands

       This filter supports the all above options as commands.

   atrim
       Trim the input so that the output contains one continuous subpart of the input.

       It accepts the following parameters:

       start
           Timestamp (in seconds) of the start of the section to keep. I.e. the audio sample with the timestamp start will be the
           first sample in the output.

       end Specify time of the first audio sample that will be dropped, i.e. the audio sample immediately preceding the one with
           the timestamp end will be the last sample in the output.

       start_pts
           Same as start, except this option sets the start timestamp in samples instead of seconds.

       end_pts
           Same as end, except this option sets the end timestamp in samples instead of seconds.

       duration
           The maximum duration of the output in seconds.

       start_sample
           The number of the first sample that should be output.

       end_sample
           The number of the first sample that should be dropped.

       start, end, and duration are expressed as time duration specifications; see the Time duration section in the ffmpeg-utils(1)
       manual.

       Note that the first two sets of the start/end options and the duration option look at the frame timestamp, while the _sample
       options simply count the samples that pass through the filter. So start/end_pts and start/end_sample will give different
       results when the timestamps are wrong, inexact or do not start at zero. Also note that this filter does not modify the
       timestamps. If you wish to have the output timestamps start at zero, insert the asetpts filter after the atrim filter.

       If multiple start or end options are set, this filter tries to be greedy and keep all samples that match at least one of the
       specified constraints. To keep only the part that matches all the constraints at once, chain multiple atrim filters.

       The defaults are such that all the input is kept. So it is possible to set e.g.  just the end values to keep everything
       before the specified time.

       Examples:

       •   Drop everything except the second minute of input:

                   ffmpeg -i INPUT -af atrim=60:120

       •   Keep only the first 1000 samples:

                   ffmpeg -i INPUT -af atrim=end_sample=1000

   axcorrelate
       Calculate normalized windowed cross-correlation between two input audio streams.

       Resulted samples are always between -1 and 1 inclusive.  If result is 1 it means two input samples are highly correlated in
       that selected segment.  Result 0 means they are not correlated at all.  If result is -1 it means two input samples are out
       of phase, which means they cancel each other.

       The filter accepts the following options:

       size
           Set size of segment over which cross-correlation is calculated.  Default is 256. Allowed range is from 2 to 131072.

       algo
           Set algorithm for cross-correlation. Can be "slow" or "fast".  Default is "slow". Fast algorithm assumes mean values
           over any given segment are always zero and thus need much less calculations to make.  This is generally not true, but is
           valid for typical audio streams.

       Examples

       •   Calculate correlation between channels in stereo audio stream:

                   ffmpeg -i stereo.wav -af channelsplit,axcorrelate=size=1024:algo=fast correlation.wav

   bandpass
       Apply a two-pole Butterworth band-pass filter with central frequency frequency, and (3dB-point) band-width width.  The csg
       option selects a constant skirt gain (peak gain = Q) instead of the default: constant 0dB peak gain.  The filter roll off at
       6dB per octave (20dB per decade).

       The filter accepts the following options:

       frequency, f
           Set the filter's central frequency. Default is 3000.

       csg Constant skirt gain if set to 1. Defaults to 0.

       width_type, t
           Set method to specify band-width of filter.

           h   Hz

           q   Q-Factor

           o   octave

           s   slope

           k   kHz

       width, w
           Specify the band-width of a filter in width_type units.

       mix, m
           How much to use filtered signal in output. Default is 1.  Range is between 0 and 1.

       channels, c
           Specify which channels to filter, by default all available are filtered.

       normalize, n
           Normalize biquad coefficients, by default is disabled.  Enabling it will normalize magnitude response at DC to 0dB.

       transform, a
           Set transform type of IIR filter.

           di
           dii
           tdi
           tdii
           latt
           svf
           zdf
       precision, r
           Set precison of filtering.

           auto
               Pick automatic sample format depending on surround filters.

           s16 Always use signed 16-bit.

           s32 Always use signed 32-bit.

           f32 Always use float 32-bit.

           f64 Always use float 64-bit.

       block_size, b
           Set block size used for reverse IIR processing. If this value is set to high enough value (higher than impulse response
           length truncated when reaches near zero values) filtering will become linear phase otherwise if not big enough it will
           just produce nasty artifacts.

           Note that filter delay will be exactly this many samples when set to non-zero value.

       Commands

       This filter supports the following commands:

       frequency, f
           Change bandpass frequency.  Syntax for the command is : "frequency"

       width_type, t
           Change bandpass width_type.  Syntax for the command is : "width_type"

       width, w
           Change bandpass width.  Syntax for the command is : "width"

       mix, m
           Change bandpass mix.  Syntax for the command is : "mix"

   bandreject
       Apply a two-pole Butterworth band-reject filter with central frequency frequency, and (3dB-point) band-width width.  The
       filter roll off at 6dB per octave (20dB per decade).

       The filter accepts the following options:

       frequency, f
           Set the filter's central frequency. Default is 3000.

       width_type, t
           Set method to specify band-width of filter.

           h   Hz

           q   Q-Factor

           o   octave

           s   slope

           k   kHz

       width, w
           Specify the band-width of a filter in width_type units.

       mix, m
           How much to use filtered signal in output. Default is 1.  Range is between 0 and 1.

       channels, c
           Specify which channels to filter, by default all available are filtered.

       normalize, n
           Normalize biquad coefficients, by default is disabled.  Enabling it will normalize magnitude response at DC to 0dB.

       transform, a
           Set transform type of IIR filter.

           di
           dii
           tdi
           tdii
           latt
           svf
           zdf
       precision, r
           Set precison of filtering.

           auto
               Pick automatic sample format depending on surround filters.

           s16 Always use signed 16-bit.

           s32 Always use signed 32-bit.

           f32 Always use float 32-bit.

           f64 Always use float 64-bit.

       block_size, b
           Set block size used for reverse IIR processing. If this value is set to high enough value (higher than impulse response
           length truncated when reaches near zero values) filtering will become linear phase otherwise if not big enough it will
           just produce nasty artifacts.

           Note that filter delay will be exactly this many samples when set to non-zero value.

       Commands

       This filter supports the following commands:

       frequency, f
           Change bandreject frequency.  Syntax for the command is : "frequency"

       width_type, t
           Change bandreject width_type.  Syntax for the command is : "width_type"

       width, w
           Change bandreject width.  Syntax for the command is : "width"

       mix, m
           Change bandreject mix.  Syntax for the command is : "mix"

   bass, lowshelf
       Boost or cut the bass (lower) frequencies of the audio using a two-pole shelving filter with a response similar to that of a
       standard hi-fi's tone-controls. This is also known as shelving equalisation (EQ).

       The filter accepts the following options:

       gain, g
           Give the gain at 0 Hz. Its useful range is about -20 (for a large cut) to +20 (for a large boost).  Beware of clipping
           when using a positive gain.

       frequency, f
           Set the filter's central frequency and so can be used to extend or reduce the frequency range to be boosted or cut.  The
           default value is 100 Hz.

       width_type, t
           Set method to specify band-width of filter.

           h   Hz

           q   Q-Factor

           o   octave

           s   slope

           k   kHz

       width, w
           Determine how steep is the filter's shelf transition.

       poles, p
           Set number of poles. Default is 2.

       mix, m
           How much to use filtered signal in output. Default is 1.  Range is between 0 and 1.

       channels, c
           Specify which channels to filter, by default all available are filtered.

       normalize, n
           Normalize biquad coefficients, by default is disabled.  Enabling it will normalize magnitude response at DC to 0dB.

       transform, a
           Set transform type of IIR filter.

           di
           dii
           tdi
           tdii
           latt
           svf
           zdf
       precision, r
           Set precison of filtering.

           auto
               Pick automatic sample format depending on surround filters.

           s16 Always use signed 16-bit.

           s32 Always use signed 32-bit.

           f32 Always use float 32-bit.

           f64 Always use float 64-bit.

       block_size, b
           Set block size used for reverse IIR processing. If this value is set to high enough value (higher than impulse response
           length truncated when reaches near zero values) filtering will become linear phase otherwise if not big enough it will
           just produce nasty artifacts.

           Note that filter delay will be exactly this many samples when set to non-zero value.

       Commands

       This filter supports the following commands:

       frequency, f
           Change bass frequency.  Syntax for the command is : "frequency"

       width_type, t
           Change bass width_type.  Syntax for the command is : "width_type"

       width, w
           Change bass width.  Syntax for the command is : "width"

       gain, g
           Change bass gain.  Syntax for the command is : "gain"

       mix, m
           Change bass mix.  Syntax for the command is : "mix"

   biquad
       Apply a biquad IIR filter with the given coefficients.  Where b0, b1, b2 and a0, a1, a2 are the numerator and denominator
       coefficients respectively.  and channels, c specify which channels to filter, by default all available are filtered.

       Commands

       This filter supports the following commands:

       a0
       a1
       a2
       b0
       b1
       b2  Change biquad parameter.  Syntax for the command is : "value"

       mix, m
           How much to use filtered signal in output. Default is 1.  Range is between 0 and 1.

       channels, c
           Specify which channels to filter, by default all available are filtered.

       normalize, n
           Normalize biquad coefficients, by default is disabled.  Enabling it will normalize magnitude response at DC to 0dB.

       transform, a
           Set transform type of IIR filter.

           di
           dii
           tdi
           tdii
           latt
           svf
           zdf
       precision, r
           Set precison of filtering.

           auto
               Pick automatic sample format depending on surround filters.

           s16 Always use signed 16-bit.

           s32 Always use signed 32-bit.

           f32 Always use float 32-bit.

           f64 Always use float 64-bit.

       block_size, b
           Set block size used for reverse IIR processing. If this value is set to high enough value (higher than impulse response
           length truncated when reaches near zero values) filtering will become linear phase otherwise if not big enough it will
           just produce nasty artifacts.

           Note that filter delay will be exactly this many samples when set to non-zero value.

   bs2b
       Bauer stereo to binaural transformation, which improves headphone listening of stereo audio records.

       To enable compilation of this filter you need to configure FFmpeg with "--enable-libbs2b".

       It accepts the following parameters:

       profile
           Pre-defined crossfeed level.

           default
               Default level (fcut=700, feed=50).

           cmoy
               Chu Moy circuit (fcut=700, feed=60).

           jmeier
               Jan Meier circuit (fcut=650, feed=95).

       fcut
           Cut frequency (in Hz).

       feed
           Feed level (in Hz).

   channelmap
       Remap input channels to new locations.

       It accepts the following parameters:

       map Map channels from input to output. The argument is a '|'-separated list of mappings, each in the
           "in_channel-out_channel" or in_channel form. in_channel can be either the name of the input channel (e.g. FL for front
           left) or its index in the input channel layout.  out_channel is the name of the output channel or its index in the
           output channel layout. If out_channel is not given then it is implicitly an index, starting with zero and increasing by
           one for each mapping.

       channel_layout
           The channel layout of the output stream.

       If no mapping is present, the filter will implicitly map input channels to output channels, preserving indices.

       Examples

       •   For example, assuming a 5.1+downmix input MOV file,

                   ffmpeg -i in.mov -filter 'channelmap=map=DL-FL|DR-FR' out.wav

           will create an output WAV file tagged as stereo from the downmix channels of the input.

       •   To fix a 5.1 WAV improperly encoded in AAC's native channel order

                   ffmpeg -i in.wav -filter 'channelmap=1|2|0|5|3|4:5.1' out.wav

   channelsplit
       Split each channel from an input audio stream into a separate output stream.

       It accepts the following parameters:

       channel_layout
           The channel layout of the input stream. The default is "stereo".

       channels
           A channel layout describing the channels to be extracted as separate output streams or "all" to extract each input
           channel as a separate stream. The default is "all".

           Choosing channels not present in channel layout in the input will result in an error.

       Examples

       •   For example, assuming a stereo input MP3 file,

                   ffmpeg -i in.mp3 -filter_complex channelsplit out.mkv

           will create an output Matroska file with two audio streams, one containing only the left channel and the other the right
           channel.

       •   Split a 5.1 WAV file into per-channel files:

                   ffmpeg -i in.wav -filter_complex
                   'channelsplit=channel_layout=5.1[FL][FR][FC][LFE][SL][SR]'
                   -map '[FL]' front_left.wav -map '[FR]' front_right.wav -map '[FC]'
                   front_center.wav -map '[LFE]' lfe.wav -map '[SL]' side_left.wav -map '[SR]'
                   side_right.wav

       •   Extract only LFE from a 5.1 WAV file:

                   ffmpeg -i in.wav -filter_complex 'channelsplit=channel_layout=5.1:channels=LFE[LFE]'
                   -map '[LFE]' lfe.wav

   chorus
       Add a chorus effect to the audio.

       Can make a single vocal sound like a chorus, but can also be applied to instrumentation.

       Chorus resembles an echo effect with a short delay, but whereas with echo the delay is constant, with chorus, it is varied
       using using sinusoidal or triangular modulation.  The modulation depth defines the range the modulated delay is played
       before or after the delay. Hence the delayed sound will sound slower or faster, that is the delayed sound tuned around the
       original one, like in a chorus where some vocals are slightly off key.

       It accepts the following parameters:

       in_gain
           Set input gain. Default is 0.4.

       out_gain
           Set output gain. Default is 0.4.

       delays
           Set delays. A typical delay is around 40ms to 60ms.

       decays
           Set decays.

       speeds
           Set speeds.

       depths
           Set depths.

       Examples

       •   A single delay:

                   chorus=0.7:0.9:55:0.4:0.25:2

       •   Two delays:

                   chorus=0.6:0.9:50|60:0.4|0.32:0.25|0.4:2|1.3

       •   Fuller sounding chorus with three delays:

                   chorus=0.5:0.9:50|60|40:0.4|0.32|0.3:0.25|0.4|0.3:2|2.3|1.3

   compand
       Compress or expand the audio's dynamic range.

       It accepts the following parameters:

       attacks
       decays
           A list of times in seconds for each channel over which the instantaneous level of the input signal is averaged to
           determine its volume. attacks refers to increase of volume and decays refers to decrease of volume. For most situations,
           the attack time (response to the audio getting louder) should be shorter than the decay time, because the human ear is
           more sensitive to sudden loud audio than sudden soft audio. A typical value for attack is 0.3 seconds and a typical
           value for decay is 0.8 seconds.  If specified number of attacks & decays is lower than number of channels, the last set
           attack/decay will be used for all remaining channels.

       points
           A list of points for the transfer function, specified in dB relative to the maximum possible signal amplitude. Each key
           points list must be defined using the following syntax: "x0/y0|x1/y1|x2/y2|...." or "x0/y0 x1/y1 x2/y2 ...."

           The input values must be in strictly increasing order but the transfer function does not have to be monotonically
           rising. The point "0/0" is assumed but may be overridden (by "0/out-dBn"). Typical values for the transfer function are
           "-70/-70|-60/-20|1/0".

       soft-knee
           Set the curve radius in dB for all joints. It defaults to 0.01.

       gain
           Set the additional gain in dB to be applied at all points on the transfer function. This allows for easy adjustment of
           the overall gain.  It defaults to 0.

       volume
           Set an initial volume, in dB, to be assumed for each channel when filtering starts. This permits the user to supply a
           nominal level initially, so that, for example, a very large gain is not applied to initial signal levels before the
           companding has begun to operate. A typical value for audio which is initially quiet is -90 dB. It defaults to 0.

       delay
           Set a delay, in seconds. The input audio is analyzed immediately, but audio is delayed before being fed to the volume
           adjuster. Specifying a delay approximately equal to the attack/decay times allows the filter to effectively operate in
           predictive rather than reactive mode. It defaults to 0.

       Examples

       •   Make music with both quiet and loud passages suitable for listening to in a noisy environment:

                   compand=.3|.3:1|1:-90/-60|-60/-40|-40/-30|-20/-20:6:0:-90:0.2

           Another example for audio with whisper and explosion parts:

                   compand=0|0:1|1:-90/-900|-70/-70|-30/-9|0/-3:6:0:0:0

       •   A noise gate for when the noise is at a lower level than the signal:

                   compand=.1|.1:.2|.2:-900/-900|-50.1/-900|-50/-50:.01:0:-90:.1

       •   Here is another noise gate, this time for when the noise is at a higher level than the signal (making it, in some ways,
           similar to squelch):

                   compand=.1|.1:.1|.1:-45.1/-45.1|-45/-900|0/-900:.01:45:-90:.1

       •   2:1 compression starting at -6dB:

                   compand=points=-80/-80|-6/-6|0/-3.8|20/3.5

       •   2:1 compression starting at -9dB:

                   compand=points=-80/-80|-9/-9|0/-5.3|20/2.9

       •   2:1 compression starting at -12dB:

                   compand=points=-80/-80|-12/-12|0/-6.8|20/1.9

       •   2:1 compression starting at -18dB:

                   compand=points=-80/-80|-18/-18|0/-9.8|20/0.7

       •   3:1 compression starting at -15dB:

                   compand=points=-80/-80|-15/-15|0/-10.8|20/-5.2

       •   Compressor/Gate:

                   compand=points=-80/-105|-62/-80|-15.4/-15.4|0/-12|20/-7.6

       •   Expander:

                   compand=attacks=0:points=-80/-169|-54/-80|-49.5/-64.6|-41.1/-41.1|-25.8/-15|-10.8/-4.5|0/0|20/8.3

       •   Hard limiter at -6dB:

                   compand=attacks=0:points=-80/-80|-6/-6|20/-6

       •   Hard limiter at -12dB:

                   compand=attacks=0:points=-80/-80|-12/-12|20/-12

       •   Hard noise gate at -35 dB:

                   compand=attacks=0:points=-80/-115|-35.1/-80|-35/-35|20/20

       •   Soft limiter:

                   compand=attacks=0:points=-80/-80|-12.4/-12.4|-6/-8|0/-6.8|20/-2.8

   compensationdelay
       Compensation Delay Line is a metric based delay to compensate differing positions of microphones or speakers.

       For example, you have recorded guitar with two microphones placed in different locations. Because the front of sound wave
       has fixed speed in normal conditions, the phasing of microphones can vary and depends on their location and interposition.
       The best sound mix can be achieved when these microphones are in phase (synchronized). Note that a distance of ~30 cm
       between microphones makes one microphone capture the signal in antiphase to the other microphone. That makes the final mix
       sound moody.  This filter helps to solve phasing problems by adding different delays to each microphone track and make them
       synchronized.

       The best result can be reached when you take one track as base and synchronize other tracks one by one with it.  Remember
       that synchronization/delay tolerance depends on sample rate, too.  Higher sample rates will give more tolerance.

       The filter accepts the following parameters:

       mm  Set millimeters distance. This is compensation distance for fine tuning.  Default is 0.

       cm  Set cm distance. This is compensation distance for tightening distance setup.  Default is 0.

       m   Set meters distance. This is compensation distance for hard distance setup.  Default is 0.

       dry Set dry amount. Amount of unprocessed (dry) signal.  Default is 0.

       wet Set wet amount. Amount of processed (wet) signal.  Default is 1.

       temp
           Set temperature in degrees Celsius. This is the temperature of the environment.  Default is 20.

       Commands

       This filter supports the all above options as commands.

   crossfeed
       Apply headphone crossfeed filter.

       Crossfeed is the process of blending the left and right channels of stereo audio recording.  It is mainly used to reduce
       extreme stereo separation of low frequencies.

       The intent is to produce more speaker like sound to the listener.

       The filter accepts the following options:

       strength
           Set strength of crossfeed. Default is 0.2. Allowed range is from 0 to 1.  This sets gain of low shelf filter for side
           part of stereo image.  Default is -6dB. Max allowed is -30db when strength is set to 1.

       range
           Set soundstage wideness. Default is 0.5. Allowed range is from 0 to 1.  This sets cut off frequency of low shelf filter.
           Default is cut off near 1550 Hz. With range set to 1 cut off frequency is set to 2100 Hz.

       slope
           Set curve slope of low shelf filter. Default is 0.5.  Allowed range is from 0.01 to 1.

       level_in
           Set input gain. Default is 0.9.

       level_out
           Set output gain. Default is 1.

       block_size
           Set block size used for reverse IIR processing. If this value is set to high enough value (higher than impulse response
           length truncated when reaches near zero values) filtering will become linear phase otherwise if not big enough it will
           just produce nasty artifacts.

           Note that filter delay will be exactly this many samples when set to non-zero value.

       Commands

       This filter supports the all above options as commands.

   crystalizer
       Simple algorithm for audio noise sharpening.

       This filter linearly increases differences betweeen each audio sample.

       The filter accepts the following options:

       i   Sets the intensity of effect (default: 2.0). Must be in range between -10.0 to 0 (unchanged sound) to 10.0 (maximum
           effect).  To inverse filtering use negative value.

       c   Enable clipping. By default is enabled.

       Commands

       This filter supports the all above options as commands.

   dcshift
       Apply a DC shift to the audio.

       This can be useful to remove a DC offset (caused perhaps by a hardware problem in the recording chain) from the audio. The
       effect of a DC offset is reduced headroom and hence volume. The astats filter can be used to determine if a signal has a DC
       offset.

       shift
           Set the DC shift, allowed range is [-1, 1]. It indicates the amount to shift the audio.

       limitergain
           Optional. It should have a value much less than 1 (e.g. 0.05 or 0.02) and is used to prevent clipping.

   deesser
       Apply de-essing to the audio samples.

       i   Set intensity for triggering de-essing. Allowed range is from 0 to 1.  Default is 0.

       m   Set amount of ducking on treble part of sound. Allowed range is from 0 to 1.  Default is 0.5.

       f   How much of original frequency content to keep when de-essing. Allowed range is from 0 to 1.  Default is 0.5.

       s   Set the output mode.

           It accepts the following values:

           i   Pass input unchanged.

           o   Pass ess filtered out.

           e   Pass only ess.

               Default value is o.

   dialoguenhance
       Enhance dialogue in stereo audio.

       This filter accepts stereo input and produce surround (3.0) channels output.  The newly produced front center channel have
       enhanced speech dialogue originally available in both stereo channels.  This filter outputs front left and front right
       channels same as available in stereo input.

       The filter accepts the following options:

       original
           Set the original center factor to keep in front center channel output.  Allowed range is from 0 to 1. Default value is
           1.

       enhance
           Set the dialogue enhance factor to put in front center channel output.  Allowed range is from 0 to 3. Default value is
           1.

       voice
           Set the voice detection factor.  Allowed range is from 2 to 32. Default value is 2.

       Commands

       This filter supports the all above options as commands.

   drmeter
       Measure audio dynamic range.

       DR values of 14 and higher is found in very dynamic material. DR of 8 to 13 is found in transition material. And anything
       less that 8 have very poor dynamics and is very compressed.

       The filter accepts the following options:

       length
           Set window length in seconds used to split audio into segments of equal length.  Default is 3 seconds.

   dynaudnorm
       Dynamic Audio Normalizer.

       This filter applies a certain amount of gain to the input audio in order to bring its peak magnitude to a target level (e.g.
       0 dBFS). However, in contrast to more "simple" normalization algorithms, the Dynamic Audio Normalizer *dynamically* re-
       adjusts the gain factor to the input audio.  This allows for applying extra gain to the "quiet" sections of the audio while
       avoiding distortions or clipping the "loud" sections. In other words: The Dynamic Audio Normalizer will "even out" the
       volume of quiet and loud sections, in the sense that the volume of each section is brought to the same target level. Note,
       however, that the Dynamic Audio Normalizer achieves this goal *without* applying "dynamic range compressing". It will retain
       100% of the dynamic range *within* each section of the audio file.

       framelen, f
           Set the frame length in milliseconds. In range from 10 to 8000 milliseconds.  Default is 500 milliseconds.  The Dynamic
           Audio Normalizer processes the input audio in small chunks, referred to as frames. This is required, because a peak
           magnitude has no meaning for just a single sample value. Instead, we need to determine the peak magnitude for a
           contiguous sequence of sample values. While a "standard" normalizer would simply use the peak magnitude of the complete
           file, the Dynamic Audio Normalizer determines the peak magnitude individually for each frame. The length of a frame is
           specified in milliseconds. By default, the Dynamic Audio Normalizer uses a frame length of 500 milliseconds, which has
           been found to give good results with most files.  Note that the exact frame length, in number of samples, will be
           determined automatically, based on the sampling rate of the individual input audio file.

       gausssize, g
           Set the Gaussian filter window size. In range from 3 to 301, must be odd number. Default is 31.  Probably the most
           important parameter of the Dynamic Audio Normalizer is the "window size" of the Gaussian smoothing filter. The filter's
           window size is specified in frames, centered around the current frame. For the sake of simplicity, this must be an odd
           number. Consequently, the default value of 31 takes into account the current frame, as well as the 15 preceding frames
           and the 15 subsequent frames. Using a larger window results in a stronger smoothing effect and thus in less gain
           variation, i.e. slower gain adaptation. Conversely, using a smaller window results in a weaker smoothing effect and thus
           in more gain variation, i.e. faster gain adaptation.  In other words, the more you increase this value, the more the
           Dynamic Audio Normalizer will behave like a "traditional" normalization filter. On the contrary, the more you decrease
           this value, the more the Dynamic Audio Normalizer will behave like a dynamic range compressor.

       peak, p
           Set the target peak value. This specifies the highest permissible magnitude level for the normalized audio input. This
           filter will try to approach the target peak magnitude as closely as possible, but at the same time it also makes sure
           that the normalized signal will never exceed the peak magnitude.  A frame's maximum local gain factor is imposed
           directly by the target peak magnitude. The default value is 0.95 and thus leaves a headroom of 5%*.  It is not
           recommended to go above this value.

       maxgain, m
           Set the maximum gain factor. In range from 1.0 to 100.0. Default is 10.0.  The Dynamic Audio Normalizer determines the
           maximum possible (local) gain factor for each input frame, i.e. the maximum gain factor that does not result in clipping
           or distortion. The maximum gain factor is determined by the frame's highest magnitude sample. However, the Dynamic Audio
           Normalizer additionally bounds the frame's maximum gain factor by a predetermined (global) maximum gain factor. This is
           done in order to avoid excessive gain factors in "silent" or almost silent frames. By default, the maximum gain factor
           is 10.0, For most inputs the default value should be sufficient and it usually is not recommended to increase this
           value. Though, for input with an extremely low overall volume level, it may be necessary to allow even higher gain
           factors. Note, however, that the Dynamic Audio Normalizer does not simply apply a "hard" threshold (i.e. cut off values
           above the threshold).  Instead, a "sigmoid" threshold function will be applied. This way, the gain factors will smoothly
           approach the threshold value, but never exceed that value.

       targetrms, r
           Set the target RMS. In range from 0.0 to 1.0. Default is 0.0 - disabled.  By default, the Dynamic Audio Normalizer
           performs "peak" normalization.  This means that the maximum local gain factor for each frame is defined (only) by the
           frame's highest magnitude sample. This way, the samples can be amplified as much as possible without exceeding the
           maximum signal level, i.e. without clipping. Optionally, however, the Dynamic Audio Normalizer can also take into
           account the frame's root mean square, abbreviated RMS. In electrical engineering, the RMS is commonly used to determine
           the power of a time-varying signal. It is therefore considered that the RMS is a better approximation of the "perceived
           loudness" than just looking at the signal's peak magnitude. Consequently, by adjusting all frames to a constant RMS
           value, a uniform "perceived loudness" can be established. If a target RMS value has been specified, a frame's local gain
           factor is defined as the factor that would result in exactly that RMS value.  Note, however, that the maximum local gain
           factor is still restricted by the frame's highest magnitude sample, in order to prevent clipping.

       coupling, n
           Enable channels coupling. By default is enabled.  By default, the Dynamic Audio Normalizer will amplify all channels by
           the same amount. This means the same gain factor will be applied to all channels, i.e.  the maximum possible gain factor
           is determined by the "loudest" channel.  However, in some recordings, it may happen that the volume of the different
           channels is uneven, e.g. one channel may be "quieter" than the other one(s).  In this case, this option can be used to
           disable the channel coupling. This way, the gain factor will be determined independently for each channel, depending
           only on the individual channel's highest magnitude sample. This allows for harmonizing the volume of the different
           channels.

       correctdc, c
           Enable DC bias correction. By default is disabled.  An audio signal (in the time domain) is a sequence of sample values.
           In the Dynamic Audio Normalizer these sample values are represented in the -1.0 to 1.0 range, regardless of the original
           input format. Normally, the audio signal, or "waveform", should be centered around the zero point.  That means if we
           calculate the mean value of all samples in a file, or in a single frame, then the result should be 0.0 or at least very
           close to that value. If, however, there is a significant deviation of the mean value from 0.0, in either positive or
           negative direction, this is referred to as a DC bias or DC offset. Since a DC bias is clearly undesirable, the Dynamic
           Audio Normalizer provides optional DC bias correction.  With DC bias correction enabled, the Dynamic Audio Normalizer
           will determine the mean value, or "DC correction" offset, of each input frame and subtract that value from all of the
           frame's sample values which ensures those samples are centered around 0.0 again. Also, in order to avoid "gaps" at the
           frame boundaries, the DC correction offset values will be interpolated smoothly between neighbouring frames.

       altboundary, b
           Enable alternative boundary mode. By default is disabled.  The Dynamic Audio Normalizer takes into account a certain
           neighbourhood around each frame. This includes the preceding frames as well as the subsequent frames. However, for the
           "boundary" frames, located at the very beginning and at the very end of the audio file, not all neighbouring frames are
           available. In particular, for the first few frames in the audio file, the preceding frames are not known. And,
           similarly, for the last few frames in the audio file, the subsequent frames are not known. Thus, the question arises
           which gain factors should be assumed for the missing frames in the "boundary" region. The Dynamic Audio Normalizer
           implements two modes to deal with this situation. The default boundary mode assumes a gain factor of exactly 1.0 for the
           missing frames, resulting in a smooth "fade in" and "fade out" at the beginning and at the end of the input,
           respectively.

       compress, s
           Set the compress factor. In range from 0.0 to 30.0. Default is 0.0.  By default, the Dynamic Audio Normalizer does not
           apply "traditional" compression. This means that signal peaks will not be pruned and thus the full dynamic range will be
           retained within each local neighbourhood. However, in some cases it may be desirable to combine the Dynamic Audio
           Normalizer's normalization algorithm with a more "traditional" compression.  For this purpose, the Dynamic Audio
           Normalizer provides an optional compression (thresholding) function. If (and only if) the compression feature is
           enabled, all input frames will be processed by a soft knee thresholding function prior to the actual normalization
           process. Put simply, the thresholding function is going to prune all samples whose magnitude exceeds a certain threshold
           value.  However, the Dynamic Audio Normalizer does not simply apply a fixed threshold value. Instead, the threshold
           value will be adjusted for each individual frame.  In general, smaller parameters result in stronger compression, and
           vice versa.  Values below 3.0 are not recommended, because audible distortion may appear.

       threshold, t
           Set the target threshold value. This specifies the lowest permissible magnitude level for the audio input which will be
           normalized.  If input frame volume is above this value frame will be normalized.  Otherwise frame may not be normalized
           at all. The default value is set to 0, which means all input frames will be normalized.  This option is mostly useful if
           digital noise is not wanted to be amplified.

       channels, h
           Specify which channels to filter, by default all available channels are filtered.

       overlap, o
           Specify overlap for frames. If set to 0 (default) no frame overlapping is done.  Using >0 and <1 values will make less
           conservative gain adjustments, like when framelen option is set to smaller value, if framelen option value is
           compensated for non-zero overlap then gain adjustments will be smoother across time compared to zero overlap case.

       Commands

       This filter supports the all above options as commands.

   earwax
       Make audio easier to listen to on headphones.

       This filter adds `cues' to 44.1kHz stereo (i.e. audio CD format) audio so that when listened to on headphones the stereo
       image is moved from inside your head (standard for headphones) to outside and in front of the listener (standard for
       speakers).

       Ported from SoX.

   equalizer
       Apply a two-pole peaking equalisation (EQ) filter. With this filter, the signal-level at and around a selected frequency can
       be increased or decreased, whilst (unlike bandpass and bandreject filters) that at all other frequencies is unchanged.

       In order to produce complex equalisation curves, this filter can be given several times, each with a different central
       frequency.

       The filter accepts the following options:

       frequency, f
           Set the filter's central frequency in Hz.

       width_type, t
           Set method to specify band-width of filter.

           h   Hz

           q   Q-Factor

           o   octave

           s   slope

           k   kHz

       width, w
           Specify the band-width of a filter in width_type units.

       gain, g
           Set the required gain or attenuation in dB.  Beware of clipping when using a positive gain.

       mix, m
           How much to use filtered signal in output. Default is 1.  Range is between 0 and 1.

       channels, c
           Specify which channels to filter, by default all available are filtered.

       normalize, n
           Normalize biquad coefficients, by default is disabled.  Enabling it will normalize magnitude response at DC to 0dB.

       transform, a
           Set transform type of IIR filter.

           di
           dii
           tdi
           tdii
           latt
           svf
           zdf
       precision, r
           Set precison of filtering.

           auto
               Pick automatic sample format depending on surround filters.

           s16 Always use signed 16-bit.

           s32 Always use signed 32-bit.

           f32 Always use float 32-bit.

           f64 Always use float 64-bit.

       block_size, b
           Set block size used for reverse IIR processing. If this value is set to high enough value (higher than impulse response
           length truncated when reaches near zero values) filtering will become linear phase otherwise if not big enough it will
           just produce nasty artifacts.

           Note that filter delay will be exactly this many samples when set to non-zero value.

       Examples

       •   Attenuate 10 dB at 1000 Hz, with a bandwidth of 200 Hz:

                   equalizer=f=1000:t=h:width=200:g=-10

       •   Apply 2 dB gain at 1000 Hz with Q 1 and attenuate 5 dB at 100 Hz with Q 2:

                   equalizer=f=1000:t=q:w=1:g=2,equalizer=f=100:t=q:w=2:g=-5

       Commands

       This filter supports the following commands:

       frequency, f
           Change equalizer frequency.  Syntax for the command is : "frequency"

       width_type, t
           Change equalizer width_type.  Syntax for the command is : "width_type"

       width, w
           Change equalizer width.  Syntax for the command is : "width"

       gain, g
           Change equalizer gain.  Syntax for the command is : "gain"

       mix, m
           Change equalizer mix.  Syntax for the command is : "mix"

   extrastereo
       Linearly increases the difference between left and right channels which adds some sort of "live" effect to playback.

       The filter accepts the following options:

       m   Sets the difference coefficient (default: 2.5). 0.0 means mono sound (average of both channels), with 1.0 sound will be
           unchanged, with -1.0 left and right channels will be swapped.

       c   Enable clipping. By default is enabled.

       Commands

       This filter supports the all above options as commands.

   firequalizer
       Apply FIR Equalization using arbitrary frequency response.

       The filter accepts the following option:

       gain
           Set gain curve equation (in dB). The expression can contain variables:

           f   the evaluated frequency

           sr  sample rate

           ch  channel number, set to 0 when multichannels evaluation is disabled

           chid
               channel id, see libavutil/channel_layout.h, set to the first channel id when multichannels evaluation is disabled

           chs number of channels

           chlayout
               channel_layout, see libavutil/channel_layout.h

           and functions:

           gain_interpolate(f)
               interpolate gain on frequency f based on gain_entry

           cubic_interpolate(f)
               same as gain_interpolate, but smoother

           This option is also available as command. Default is gain_interpolate(f).

       gain_entry
           Set gain entry for gain_interpolate function. The expression can contain functions:

           entry(f, g)
               store gain entry at frequency f with value g

           This option is also available as command.

       delay
           Set filter delay in seconds. Higher value means more accurate.  Default is 0.01.

       accuracy
           Set filter accuracy in Hz. Lower value means more accurate.  Default is 5.

       wfunc
           Set window function. Acceptable values are:

           rectangular
               rectangular window, useful when gain curve is already smooth

           hann
               hann window (default)

           hamming
               hamming window

           blackman
               blackman window

           nuttall3
               3-terms continuous 1st derivative nuttall window

           mnuttall3
               minimum 3-terms discontinuous nuttall window

           nuttall
               4-terms continuous 1st derivative nuttall window

           bnuttall
               minimum 4-terms discontinuous nuttall (blackman-nuttall) window

           bharris
               blackman-harris window

           tukey
               tukey window

       fixed
           If enabled, use fixed number of audio samples. This improves speed when filtering with large delay. Default is disabled.

       multi
           Enable multichannels evaluation on gain. Default is disabled.

       zero_phase
           Enable zero phase mode by subtracting timestamp to compensate delay.  Default is disabled.

       scale
           Set scale used by gain. Acceptable values are:

           linlin
               linear frequency, linear gain

           linlog
               linear frequency, logarithmic (in dB) gain (default)

           loglin
               logarithmic (in octave scale where 20 Hz is 0) frequency, linear gain

           loglog
               logarithmic frequency, logarithmic gain

       dumpfile
           Set file for dumping, suitable for gnuplot.

       dumpscale
           Set scale for dumpfile. Acceptable values are same with scale option.  Default is linlog.

       fft2
           Enable 2-channel convolution using complex FFT. This improves speed significantly.  Default is disabled.

       min_phase
           Enable minimum phase impulse response. Default is disabled.

       Examples

       •   lowpass at 1000 Hz:

                   firequalizer=gain='if(lt(f,1000), 0, -INF)'

       •   lowpass at 1000 Hz with gain_entry:

                   firequalizer=gain_entry='entry(1000,0); entry(1001, -INF)'

       •   custom equalization:

                   firequalizer=gain_entry='entry(100,0); entry(400, -4); entry(1000, -6); entry(2000, 0)'

       •   higher delay with zero phase to compensate delay:

                   firequalizer=delay=0.1:fixed=on:zero_phase=on

       •   lowpass on left channel, highpass on right channel:

                   firequalizer=gain='if(eq(chid,1), gain_interpolate(f), if(eq(chid,2), gain_interpolate(1e6+f), 0))'
                   :gain_entry='entry(1000, 0); entry(1001,-INF); entry(1e6+1000,0)':multi=on

   flanger
       Apply a flanging effect to the audio.

       The filter accepts the following options:

       delay
           Set base delay in milliseconds. Range from 0 to 30. Default value is 0.

       depth
           Set added sweep delay in milliseconds. Range from 0 to 10. Default value is 2.

       regen
           Set percentage regeneration (delayed signal feedback). Range from -95 to 95.  Default value is 0.

       width
           Set percentage of delayed signal mixed with original. Range from 0 to 100.  Default value is 71.

       speed
           Set sweeps per second (Hz). Range from 0.1 to 10. Default value is 0.5.

       shape
           Set swept wave shape, can be triangular or sinusoidal.  Default value is sinusoidal.

       phase
           Set swept wave percentage-shift for multi channel. Range from 0 to 100.  Default value is 25.

       interp
           Set delay-line interpolation, linear or quadratic.  Default is linear.

   haas
       Apply Haas effect to audio.

       Note that this makes most sense to apply on mono signals.  With this filter applied to mono signals it give some
       directionality and stretches its stereo image.

       The filter accepts the following options:

       level_in
           Set input level. By default is 1, or 0dB

       level_out
           Set output level. By default is 1, or 0dB.

       side_gain
           Set gain applied to side part of signal. By default is 1.

       middle_source
           Set kind of middle source. Can be one of the following:

           left
               Pick left channel.

           right
               Pick right channel.

           mid Pick middle part signal of stereo image.

           side
               Pick side part signal of stereo image.

       middle_phase
           Change middle phase. By default is disabled.

       left_delay
           Set left channel delay. By default is 2.05 milliseconds.

       left_balance
           Set left channel balance. By default is -1.

       left_gain
           Set left channel gain. By default is 1.

       left_phase
           Change left phase. By default is disabled.

       right_delay
           Set right channel delay. By defaults is 2.12 milliseconds.

       right_balance
           Set right channel balance. By default is 1.

       right_gain
           Set right channel gain. By default is 1.

       right_phase
           Change right phase. By default is enabled.

   hdcd
       Decodes High Definition Compatible Digital (HDCD) data. A 16-bit PCM stream with embedded HDCD codes is expanded into a
       20-bit PCM stream.

       The filter supports the Peak Extend and Low-level Gain Adjustment features of HDCD, and detects the Transient Filter flag.

               ffmpeg -i HDCD16.flac -af hdcd OUT24.flac

       When using the filter with wav, note the default encoding for wav is 16-bit, so the resulting 20-bit stream will be
       truncated back to 16-bit. Use something like -acodec pcm_s24le after the filter to get 24-bit PCM output.

               ffmpeg -i HDCD16.wav -af hdcd OUT16.wav
               ffmpeg -i HDCD16.wav -af hdcd -c:a pcm_s24le OUT24.wav

       The filter accepts the following options:

       disable_autoconvert
           Disable any automatic format conversion or resampling in the filter graph.

       process_stereo
           Process the stereo channels together. If target_gain does not match between channels, consider it invalid and use the
           last valid target_gain.

       cdt_ms
           Set the code detect timer period in ms.

       force_pe
           Always extend peaks above -3dBFS even if PE isn't signaled.

       analyze_mode
           Replace audio with a solid tone and adjust the amplitude to signal some specific aspect of the decoding process. The
           output file can be loaded in an audio editor alongside the original to aid analysis.

           "analyze_mode=pe:force_pe=true" can be used to see all samples above the PE level.

           Modes are:

           0, off
               Disabled

           1, lle
               Gain adjustment level at each sample

           2, pe
               Samples where peak extend occurs

           3, cdt
               Samples where the code detect timer is active

           4, tgm
               Samples where the target gain does not match between channels

   headphone
       Apply head-related transfer functions (HRTFs) to create virtual loudspeakers around the user for binaural listening via
       headphones.  The HRIRs are provided via additional streams, for each channel one stereo input stream is needed.

       The filter accepts the following options:

       map Set mapping of input streams for convolution.  The argument is a '|'-separated list of channel names in order as they
           are given as additional stream inputs for filter.  This also specify number of input streams. Number of input streams
           must be not less than number of channels in first stream plus one.

       gain
           Set gain applied to audio. Value is in dB. Default is 0.

       type
           Set processing type. Can be time or freq. time is processing audio in time domain which is slow.  freq is processing
           audio in frequency domain which is fast.  Default is freq.

       lfe Set custom gain for LFE channels. Value is in dB. Default is 0.

       size
           Set size of frame in number of samples which will be processed at once.  Default value is 1024. Allowed range is from
           1024 to 96000.

       hrir
           Set format of hrir stream.  Default value is stereo. Alternative value is multich.  If value is set to stereo, number of
           additional streams should be greater or equal to number of input channels in first input stream.  Also each additional
           stream should have stereo number of channels.  If value is set to multich, number of additional streams should be
           exactly one. Also number of input channels of additional stream should be equal or greater than twice number of channels
           of first input stream.

       Examples

       •   Full example using wav files as coefficients with amovie filters for 7.1 downmix, each amovie filter use stereo file
           with IR coefficients as input.  The files give coefficients for each position of virtual loudspeaker:

                   ffmpeg -i input.wav
                   -filter_complex "amovie=azi_270_ele_0_DFC.wav[sr];amovie=azi_90_ele_0_DFC.wav[sl];amovie=azi_225_ele_0_DFC.wav[br];amovie=azi_135_ele_0_DFC.wav[bl];amovie=azi_0_ele_0_DFC.wav,asplit[fc][lfe];amovie=azi_35_ele_0_DFC.wav[fl];amovie=azi_325_ele_0_DFC.wav[fr];[0:a][fl][fr][fc][lfe][bl][br][sl][sr]headphone=FL|FR|FC|LFE|BL|BR|SL|SR"
                   output.wav

       •   Full example using wav files as coefficients with amovie filters for 7.1 downmix, but now in multich hrir format.

                   ffmpeg -i input.wav -filter_complex "amovie=minp.wav[hrirs];[0:a][hrirs]headphone=map=FL|FR|FC|LFE|BL|BR|SL|SR:hrir=multich"
                   output.wav

   highpass
       Apply a high-pass filter with 3dB point frequency.  The filter can be either single-pole, or double-pole (the default).  The
       filter roll off at 6dB per pole per octave (20dB per pole per decade).

       The filter accepts the following options:

       frequency, f
           Set frequency in Hz. Default is 3000.

       poles, p
           Set number of poles. Default is 2.

       width_type, t
           Set method to specify band-width of filter.

           h   Hz

           q   Q-Factor

           o   octave

           s   slope

           k   kHz

       width, w
           Specify the band-width of a filter in width_type units.  Applies only to double-pole filter.  The default is 0.707q and
           gives a Butterworth response.

       mix, m
           How much to use filtered signal in output. Default is 1.  Range is between 0 and 1.

       channels, c
           Specify which channels to filter, by default all available are filtered.

       normalize, n
           Normalize biquad coefficients, by default is disabled.  Enabling it will normalize magnitude response at DC to 0dB.

       transform, a
           Set transform type of IIR filter.

           di
           dii
           tdi
           tdii
           latt
           svf
           zdf
       precision, r
           Set precison of filtering.

           auto
               Pick automatic sample format depending on surround filters.

           s16 Always use signed 16-bit.

           s32 Always use signed 32-bit.

           f32 Always use float 32-bit.

           f64 Always use float 64-bit.

       block_size, b
           Set block size used for reverse IIR processing. If this value is set to high enough value (higher than impulse response
           length truncated when reaches near zero values) filtering will become linear phase otherwise if not big enough it will
           just produce nasty artifacts.

           Note that filter delay will be exactly this many samples when set to non-zero value.

       Commands

       This filter supports the following commands:

       frequency, f
           Change highpass frequency.  Syntax for the command is : "frequency"

       width_type, t
           Change highpass width_type.  Syntax for the command is : "width_type"

       width, w
           Change highpass width.  Syntax for the command is : "width"

       mix, m
           Change highpass mix.  Syntax for the command is : "mix"

   join
       Join multiple input streams into one multi-channel stream.

       It accepts the following parameters:

       inputs
           The number of input streams. It defaults to 2.

       channel_layout
           The desired output channel layout. It defaults to stereo.

       map Map channels from inputs to output. The argument is a '|'-separated list of mappings, each in the
           "input_idx.in_channel-out_channel" form. input_idx is the 0-based index of the input stream. in_channel can be either
           the name of the input channel (e.g. FL for front left) or its index in the specified input stream. out_channel is the
           name of the output channel.

       The filter will attempt to guess the mappings when they are not specified explicitly. It does so by first trying to find an
       unused matching input channel and if that fails it picks the first unused input channel.

       Join 3 inputs (with properly set channel layouts):

               ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex join=inputs=3 OUTPUT

       Build a 5.1 output from 6 single-channel streams:

               ffmpeg -i fl -i fr -i fc -i sl -i sr -i lfe -filter_complex
               'join=inputs=6:channel_layout=5.1:map=0.0-FL|1.0-FR|2.0-FC|3.0-SL|4.0-SR|5.0-LFE'
               out

   ladspa
       Load a LADSPA (Linux Audio Developer's Simple Plugin API) plugin.

       To enable compilation of this filter you need to configure FFmpeg with "--enable-ladspa".

       file, f
           Specifies the name of LADSPA plugin library to load. If the environment variable LADSPA_PATH is defined, the LADSPA
           plugin is searched in each one of the directories specified by the colon separated list in LADSPA_PATH, otherwise in the
           standard LADSPA paths, which are in this order: HOME/.ladspa/lib/, /usr/local/lib/ladspa/, /usr/lib/ladspa/.

       plugin, p
           Specifies the plugin within the library. Some libraries contain only one plugin, but others contain many of them. If
           this is not set filter will list all available plugins within the specified library.

       controls, c
           Set the '|' separated list of controls which are zero or more floating point values that determine the behavior of the
           loaded plugin (for example delay, threshold or gain).  Controls need to be defined using the following syntax:
           c0=value0|c1=value1|c2=value2|..., where valuei is the value set on the i-th control.  Alternatively they can be also
           defined using the following syntax: value0|value1|value2|..., where valuei is the value set on the i-th control.  If
           controls is set to "help", all available controls and their valid ranges are printed.

       sample_rate, s
           Specify the sample rate, default to 44100. Only used if plugin have zero inputs.

       nb_samples, n
           Set the number of samples per channel per each output frame, default is 1024. Only used if plugin have zero inputs.

       duration, d
           Set the minimum duration of the sourced audio. See the Time duration section in the ffmpeg-utils(1) manual for the
           accepted syntax.  Note that the resulting duration may be greater than the specified duration, as the generated audio is
           always cut at the end of a complete frame.  If not specified, or the expressed duration is negative, the audio is
           supposed to be generated forever.  Only used if plugin have zero inputs.

       latency, l
           Enable latency compensation, by default is disabled.  Only used if plugin have inputs.

       Examples

       •   List all available plugins within amp (LADSPA example plugin) library:

                   ladspa=file=amp

       •   List all available controls and their valid ranges for "vcf_notch" plugin from "VCF" library:

                   ladspa=f=vcf:p=vcf_notch:c=help

       •   Simulate low quality audio equipment using "Computer Music Toolkit" (CMT) plugin library:

                   ladspa=file=cmt:plugin=lofi:controls=c0=22|c1=12|c2=12

       •   Add reverberation to the audio using TAP-plugins (Tom's Audio Processing plugins):

                   ladspa=file=tap_reverb:tap_reverb

       •   Generate white noise, with 0.2 amplitude:

                   ladspa=file=cmt:noise_source_white:c=c0=.2

       •   Generate 20 bpm clicks using plugin "C* Click - Metronome" from the "C* Audio Plugin Suite" (CAPS) library:

                   ladspa=file=caps:Click:c=c1=20'

       •   Apply "C* Eq10X2 - Stereo 10-band equaliser" effect:

                   ladspa=caps:Eq10X2:c=c0=-48|c9=-24|c3=12|c4=2

       •   Increase volume by 20dB using fast lookahead limiter from Steve Harris "SWH Plugins" collection:

                   ladspa=fast_lookahead_limiter_1913:fastLookaheadLimiter:20|0|2

       •   Attenuate low frequencies using Multiband EQ from Steve Harris "SWH Plugins" collection:

                   ladspa=mbeq_1197:mbeq:-24|-24|-24|0|0|0|0|0|0|0|0|0|0|0|0

       •   Reduce stereo image using "Narrower" from the "C* Audio Plugin Suite" (CAPS) library:

                   ladspa=caps:Narrower

       •   Another white noise, now using "C* Audio Plugin Suite" (CAPS) library:

                   ladspa=caps:White:.2

       •   Some fractal noise, using "C* Audio Plugin Suite" (CAPS) library:

                   ladspa=caps:Fractal:c=c1=1

       •   Dynamic volume normalization using "VLevel" plugin:

                   ladspa=vlevel-ladspa:vlevel_mono

       Commands

       This filter supports the following commands:

       cN  Modify the N-th control value.

           If the specified value is not valid, it is ignored and prior one is kept.

   loudnorm
       EBU R128 loudness normalization. Includes both dynamic and linear normalization modes.  Support for both single pass
       (livestreams, files) and double pass (files) modes.  This algorithm can target IL, LRA, and maximum true peak. In dynamic
       mode, to accurately detect true peaks, the audio stream will be upsampled to 192 kHz.  Use the "-ar" option or "aresample"
       filter to explicitly set an output sample rate.

       The filter accepts the following options:

       I, i
           Set integrated loudness target.  Range is -70.0 - -5.0. Default value is -24.0.

       LRA, lra
           Set loudness range target.  Range is 1.0 - 50.0. Default value is 7.0.

       TP, tp
           Set maximum true peak.  Range is -9.0 - +0.0. Default value is -2.0.

       measured_I, measured_i
           Measured IL of input file.  Range is -99.0 - +0.0.

       measured_LRA, measured_lra
           Measured LRA of input file.  Range is  0.0 - 99.0.

       measured_TP, measured_tp
           Measured true peak of input file.  Range is  -99.0 - +99.0.

       measured_thresh
           Measured threshold of input file.  Range is -99.0 - +0.0.

       offset
           Set offset gain. Gain is applied before the true-peak limiter.  Range is  -99.0 - +99.0. Default is +0.0.

       linear
           Normalize by linearly scaling the source audio.  "measured_I", "measured_LRA", "measured_TP", and "measured_thresh" must
           all be specified. Target LRA shouldn't be lower than source LRA and the change in integrated loudness shouldn't result
           in a true peak which exceeds the target TP. If any of these conditions aren't met, normalization mode will revert to
           dynamic.  Options are "true" or "false". Default is "true".

       dual_mono
           Treat mono input files as "dual-mono". If a mono file is intended for playback on a stereo system, its EBU R128
           measurement will be perceptually incorrect.  If set to "true", this option will compensate for this effect.  Multi-
           channel input files are not affected by this option.  Options are true or false. Default is false.

       print_format
           Set print format for stats. Options are summary, json, or none.  Default value is none.

   lowpass
       Apply a low-pass filter with 3dB point frequency.  The filter can be either single-pole or double-pole (the default).  The
       filter roll off at 6dB per pole per octave (20dB per pole per decade).

       The filter accepts the following options:

       frequency, f
           Set frequency in Hz. Default is 500.

       poles, p
           Set number of poles. Default is 2.

       width_type, t
           Set method to specify band-width of filter.

           h   Hz

           q   Q-Factor

           o   octave

           s   slope

           k   kHz

       width, w
           Specify the band-width of a filter in width_type units.  Applies only to double-pole filter.  The default is 0.707q and
           gives a Butterworth response.

       mix, m
           How much to use filtered signal in output. Default is 1.  Range is between 0 and 1.

       channels, c
           Specify which channels to filter, by default all available are filtered.

       normalize, n
           Normalize biquad coefficients, by default is disabled.  Enabling it will normalize magnitude response at DC to 0dB.

       transform, a
           Set transform type of IIR filter.

           di
           dii
           tdi
           tdii
           latt
           svf
           zdf
       precision, r
           Set precison of filtering.

           auto
               Pick automatic sample format depending on surround filters.

           s16 Always use signed 16-bit.

           s32 Always use signed 32-bit.

           f32 Always use float 32-bit.

           f64 Always use float 64-bit.

       block_size, b
           Set block size used for reverse IIR processing. If this value is set to high enough value (higher than impulse response
           length truncated when reaches near zero values) filtering will become linear phase otherwise if not big enough it will
           just produce nasty artifacts.

           Note that filter delay will be exactly this many samples when set to non-zero value.

       Examples

       •   Lowpass only LFE channel, it LFE is not present it does nothing:

                   lowpass=c=LFE

       Commands

       This filter supports the following commands:

       frequency, f
           Change lowpass frequency.  Syntax for the command is : "frequency"

       width_type, t
           Change lowpass width_type.  Syntax for the command is : "width_type"

       width, w
           Change lowpass width.  Syntax for the command is : "width"

       mix, m
           Change lowpass mix.  Syntax for the command is : "mix"

   lv2
       Load a LV2 (LADSPA Version 2) plugin.

       To enable compilation of this filter you need to configure FFmpeg with "--enable-lv2".

       plugin, p
           Specifies the plugin URI. You may need to escape ':'.

       controls, c
           Set the '|' separated list of controls which are zero or more floating point values that determine the behavior of the
           loaded plugin (for example delay, threshold or gain).  If controls is set to "help", all available controls and their
           valid ranges are printed.

       sample_rate, s
           Specify the sample rate, default to 44100. Only used if plugin have zero inputs.

       nb_samples, n
           Set the number of samples per channel per each output frame, default is 1024. Only used if plugin have zero inputs.

       duration, d
           Set the minimum duration of the sourced audio. See the Time duration section in the ffmpeg-utils(1) manual for the
           accepted syntax.  Note that the resulting duration may be greater than the specified duration, as the generated audio is
           always cut at the end of a complete frame.  If not specified, or the expressed duration is negative, the audio is
           supposed to be generated forever.  Only used if plugin have zero inputs.

       Examples

       •   Apply bass enhancer plugin from Calf:

                   lv2=p=http\\\\://calf.sourceforge.net/plugins/BassEnhancer:c=amount=2

       •   Apply vinyl plugin from Calf:

                   lv2=p=http\\\\://calf.sourceforge.net/plugins/Vinyl:c=drone=0.2|aging=0.5

       •   Apply bit crusher plugin from ArtyFX:

                   lv2=p=http\\\\://www.openavproductions.com/artyfx#bitta:c=crush=0.3

       Commands

       This filter supports all options that are exported by plugin as commands.

   mcompand
       Multiband Compress or expand the audio's dynamic range.

       The input audio is divided into bands using 4th order Linkwitz-Riley IIRs.  This is akin to the crossover of a loudspeaker,
       and results in flat frequency response when absent compander action.

       It accepts the following parameters:

       args
           This option syntax is: attack,decay,[attack,decay..] soft-knee points crossover_frequency [delay [initial_volume
           [gain]]] | attack,decay ...  For explanation of each item refer to compand filter documentation.

   pan
       Mix channels with specific gain levels. The filter accepts the output channel layout followed by a set of channels
       definitions.

       This filter is also designed to efficiently remap the channels of an audio stream.

       The filter accepts parameters of the form: "l|outdef|outdef|..."

       l   output channel layout or number of channels

       outdef
           output channel specification, of the form: "out_name=[gain*]in_name[(+-)[gain*]in_name...]"

       out_name
           output channel to define, either a channel name (FL, FR, etc.) or a channel number (c0, c1, etc.)

       gain
           multiplicative coefficient for the channel, 1 leaving the volume unchanged

       in_name
           input channel to use, see out_name for details; it is not possible to mix named and numbered input channels

       If the `=' in a channel specification is replaced by `<', then the gains for that specification will be renormalized so that
       the total is 1, thus avoiding clipping noise.

       Mixing examples

       For example, if you want to down-mix from stereo to mono, but with a bigger factor for the left channel:

               pan=1c|c0=0.9*c0+0.1*c1

       A customized down-mix to stereo that works automatically for 3-, 4-, 5- and 7-channels surround:

               pan=stereo| FL < FL + 0.5*FC + 0.6*BL + 0.6*SL | FR < FR + 0.5*FC + 0.6*BR + 0.6*SR

       Note that ffmpeg integrates a default down-mix (and up-mix) system that should be preferred (see "-ac" option) unless you
       have very specific needs.

       Remapping examples

       The channel remapping will be effective if, and only if:

       *<gain coefficients are zeroes or ones,>
       *<only one input per channel output,>

       If all these conditions are satisfied, the filter will notify the user ("Pure channel mapping detected"), and use an
       optimized and lossless method to do the remapping.

       For example, if you have a 5.1 source and want a stereo audio stream by dropping the extra channels:

               pan="stereo| c0=FL | c1=FR"

       Given the same source, you can also switch front left and front right channels and keep the input channel layout:

               pan="5.1| c0=c1 | c1=c0 | c2=c2 | c3=c3 | c4=c4 | c5=c5"

       If the input is a stereo audio stream, you can mute the front left channel (and still keep the stereo channel layout) with:

               pan="stereo|c1=c1"

       Still with a stereo audio stream input, you can copy the right channel in both front left and right:

               pan="stereo| c0=FR | c1=FR"

   replaygain
       ReplayGain scanner filter. This filter takes an audio stream as an input and outputs it unchanged.  At end of filtering it
       displays "track_gain" and "track_peak".

   resample
       Convert the audio sample format, sample rate and channel layout. It is not meant to be used directly.

   rubberband
       Apply time-stretching and pitch-shifting with librubberband.

       To enable compilation of this filter, you need to configure FFmpeg with "--enable-librubberband".

       The filter accepts the following options:

       tempo
           Set tempo scale factor.

       pitch
           Set pitch scale factor.

       transients
           Set transients detector.  Possible values are:

           crisp
           mixed
           smooth
       detector
           Set detector.  Possible values are:

           compound
           percussive
           soft
       phase
           Set phase.  Possible values are:

           laminar
           independent
       window
           Set processing window size.  Possible values are:

           standard
           short
           long
       smoothing
           Set smoothing.  Possible values are:

           off
           on
       formant
           Enable formant preservation when shift pitching.  Possible values are:

           shifted
           preserved
       pitchq
           Set pitch quality.  Possible values are:

           quality
           speed
           consistency
       channels
           Set channels.  Possible values are:

           apart
           together

       Commands

       This filter supports the following commands:

       tempo
           Change filter tempo scale factor.  Syntax for the command is : "tempo"

       pitch
           Change filter pitch scale factor.  Syntax for the command is : "pitch"

   sidechaincompress
       This filter acts like normal compressor but has the ability to compress detected signal using second input signal.  It needs
       two input streams and returns one output stream.  First input stream will be processed depending on second stream signal.
       The filtered signal then can be filtered with other filters in later stages of processing. See pan and amerge filter.

       The filter accepts the following options:

       level_in
           Set input gain. Default is 1. Range is between 0.015625 and 64.

       mode
           Set mode of compressor operation. Can be "upward" or "downward".  Default is "downward".

       threshold
           If a signal of second stream raises above this level it will affect the gain reduction of first stream.  By default is
           0.125. Range is between 0.00097563 and 1.

       ratio
           Set a ratio about which the signal is reduced. 1:2 means that if the level raised 4dB above the threshold, it will be
           only 2dB above after the reduction.  Default is 2. Range is between 1 and 20.

       attack
           Amount of milliseconds the signal has to rise above the threshold before gain reduction starts. Default is 20. Range is
           between 0.01 and 2000.

       release
           Amount of milliseconds the signal has to fall below the threshold before reduction is decreased again. Default is 250.
           Range is between 0.01 and 9000.

       makeup
           Set the amount by how much signal will be amplified after processing.  Default is 1. Range is from 1 to 64.

       knee
           Curve the sharp knee around the threshold to enter gain reduction more softly.  Default is 2.82843. Range is between 1
           and 8.

       link
           Choose if the "average" level between all channels of side-chain stream or the louder("maximum") channel of side-chain
           stream affects the reduction. Default is "average".

       detection
           Should the exact signal be taken in case of "peak" or an RMS one in case of "rms". Default is "rms" which is mainly
           smoother.

       level_sc
           Set sidechain gain. Default is 1. Range is between 0.015625 and 64.

       mix How much to use compressed signal in output. Default is 1.  Range is between 0 and 1.

       Commands

       This filter supports the all above options as commands.

       Examples

       •   Full ffmpeg example taking 2 audio inputs, 1st input to be compressed depending on the signal of 2nd input and later
           compressed signal to be merged with 2nd input:

                   ffmpeg -i main.flac -i sidechain.flac -filter_complex "[1:a]asplit=2[sc][mix];[0:a][sc]sidechaincompress[compr];[compr][mix]amerge"

   sidechaingate
       A sidechain gate acts like a normal (wideband) gate but has the ability to filter the detected signal before sending it to
       the gain reduction stage.  Normally a gate uses the full range signal to detect a level above the threshold.  For example:
       If you cut all lower frequencies from your sidechain signal the gate will decrease the volume of your track only if not
       enough highs appear. With this technique you are able to reduce the resonation of a natural drum or remove "rumbling" of
       muted strokes from a heavily distorted guitar.  It needs two input streams and returns one output stream.  First input
       stream will be processed depending on second stream signal.

       The filter accepts the following options:

       level_in
           Set input level before filtering.  Default is 1. Allowed range is from 0.015625 to 64.

       mode
           Set the mode of operation. Can be "upward" or "downward".  Default is "downward". If set to "upward" mode, higher parts
           of signal will be amplified, expanding dynamic range in upward direction.  Otherwise, in case of "downward" lower parts
           of signal will be reduced.

       range
           Set the level of gain reduction when the signal is below the threshold.  Default is 0.06125. Allowed range is from 0 to
           1.  Setting this to 0 disables reduction and then filter behaves like expander.

       threshold
           If a signal rises above this level the gain reduction is released.  Default is 0.125. Allowed range is from 0 to 1.

       ratio
           Set a ratio about which the signal is reduced.  Default is 2. Allowed range is from 1 to 9000.

       attack
           Amount of milliseconds the signal has to rise above the threshold before gain reduction stops.  Default is 20
           milliseconds. Allowed range is from 0.01 to 9000.

       release
           Amount of milliseconds the signal has to fall below the threshold before the reduction is increased again. Default is
           250 milliseconds.  Allowed range is from 0.01 to 9000.

       makeup
           Set amount of amplification of signal after processing.  Default is 1. Allowed range is from 1 to 64.

       knee
           Curve the sharp knee around the threshold to enter gain reduction more softly.  Default is 2.828427125. Allowed range is
           from 1 to 8.

       detection
           Choose if exact signal should be taken for detection or an RMS like one.  Default is rms. Can be peak or rms.

       link
           Choose if the average level between all channels or the louder channel affects the reduction.  Default is average. Can
           be average or maximum.

       level_sc
           Set sidechain gain. Default is 1. Range is from 0.015625 to 64.

       Commands

       This filter supports the all above options as commands.

   silencedetect
       Detect silence in an audio stream.

       This filter logs a message when it detects that the input audio volume is less or equal to a noise tolerance value for a
       duration greater or equal to the minimum detected noise duration.

       The printed times and duration are expressed in seconds. The "lavfi.silence_start" or "lavfi.silence_start.X" metadata key
       is set on the first frame whose timestamp equals or exceeds the detection duration and it contains the timestamp of the
       first frame of the silence.

       The "lavfi.silence_duration" or "lavfi.silence_duration.X" and "lavfi.silence_end" or "lavfi.silence_end.X" metadata keys
       are set on the first frame after the silence. If mono is enabled, and each channel is evaluated separately, the ".X"
       suffixed keys are used, and "X" corresponds to the channel number.

       The filter accepts the following options:

       noise, n
           Set noise tolerance. Can be specified in dB (in case "dB" is appended to the specified value) or amplitude ratio.
           Default is -60dB, or 0.001.

       duration, d
           Set silence duration until notification (default is 2 seconds). See the Time duration section in the ffmpeg-utils(1)
           manual for the accepted syntax.

       mono, m
           Process each channel separately, instead of combined. By default is disabled.

       Examples

       •   Detect 5 seconds of silence with -50dB noise tolerance:

                   silencedetect=n=-50dB:d=5

       •   Complete example with ffmpeg to detect silence with 0.0001 noise tolerance in silence.mp3:

                   ffmpeg -i silence.mp3 -af silencedetect=noise=0.0001 -f null -

   silenceremove
       Remove silence from the beginning, middle or end of the audio.

       The filter accepts the following options:

       start_periods
           This value is used to indicate if audio should be trimmed at beginning of the audio. A value of zero indicates no
           silence should be trimmed from the beginning. When specifying a non-zero value, it trims audio up until it finds non-
           silence. Normally, when trimming silence from beginning of audio the start_periods will be 1 but it can be increased to
           higher values to trim all audio up to specific count of non-silence periods.  Default value is 0.

       start_duration
           Specify the amount of time that non-silence must be detected before it stops trimming audio. By increasing the duration,
           bursts of noises can be treated as silence and trimmed off. Default value is 0.

       start_threshold
           This indicates what sample value should be treated as silence. For digital audio, a value of 0 may be fine but for audio
           recorded from analog, you may wish to increase the value to account for background noise.  Can be specified in dB (in
           case "dB" is appended to the specified value) or amplitude ratio. Default value is 0.

       start_silence
           Specify max duration of silence at beginning that will be kept after trimming. Default is 0, which is equal to trimming
           all samples detected as silence.

       start_mode
           Specify mode of detection of silence end in start of multi-channel audio.  Can be any or all. Default is any.  With any,
           any sample that is detected as non-silence will cause stopped trimming of silence.  With all, only if all channels are
           detected as non-silence will cause stopped trimming of silence.

       stop_periods
           Set the count for trimming silence from the end of audio.  To remove silence from the middle of a file, specify a
           stop_periods that is negative. This value is then treated as a positive value and is used to indicate the effect should
           restart processing as specified by start_periods, making it suitable for removing periods of silence in the middle of
           the audio.  Default value is 0.

       stop_duration
           Specify a duration of silence that must exist before audio is not copied any more. By specifying a higher duration,
           silence that is wanted can be left in the audio.  Default value is 0.

       stop_threshold
           This is the same as start_threshold but for trimming silence from the end of audio.  Can be specified in dB (in case
           "dB" is appended to the specified value) or amplitude ratio. Default value is 0.

       stop_silence
           Specify max duration of silence at end that will be kept after trimming. Default is 0, which is equal to trimming all
           samples detected as silence.

       stop_mode
           Specify mode of detection of silence start in end of multi-channel audio.  Can be any or all. Default is any.  With any,
           any sample that is detected as non-silence will cause stopped trimming of silence.  With all, only if all channels are
           detected as non-silence will cause stopped trimming of silence.

       detection
           Set how is silence detected. Can be "rms" or "peak". Second is faster and works better with digital silence which is
           exactly 0.  Default value is "rms".

       window
           Set duration in number of seconds used to calculate size of window in number of samples for detecting silence.  Default
           value is 0.02. Allowed range is from 0 to 10.

       Examples

       •   The following example shows how this filter can be used to start a recording that does not contain the delay at the
           start which usually occurs between pressing the record button and the start of the performance:

                   silenceremove=start_periods=1:start_duration=5:start_threshold=0.02

       •   Trim all silence encountered from beginning to end where there is more than 1 second of silence in audio:

                   silenceremove=stop_periods=-1:stop_duration=1:stop_threshold=-90dB

       •   Trim all digital silence samples, using peak detection, from beginning to end where there is more than 0 samples of
           digital silence in audio and digital silence is detected in all channels at same positions in stream:

                   silenceremove=window=0:detection=peak:stop_mode=all:start_mode=all:stop_periods=-1:stop_threshold=0

   sofalizer
       SOFAlizer uses head-related transfer functions (HRTFs) to create virtual loudspeakers around the user for binaural listening
       via headphones (audio formats up to 9 channels supported).  The HRTFs are stored in SOFA files (see
       <http://www.sofacoustics.org/> for a database).  SOFAlizer is developed at the Acoustics Research Institute (ARI) of the
       Austrian Academy of Sciences.

       To enable compilation of this filter you need to configure FFmpeg with "--enable-libmysofa".

       The filter accepts the following options:

       sofa
           Set the SOFA file used for rendering.

       gain
           Set gain applied to audio. Value is in dB. Default is 0.

       rotation
           Set rotation of virtual loudspeakers in deg. Default is 0.

       elevation
           Set elevation of virtual speakers in deg. Default is 0.

       radius
           Set distance in meters between loudspeakers and the listener with near-field HRTFs. Default is 1.

       type
           Set processing type. Can be time or freq. time is processing audio in time domain which is slow.  freq is processing
           audio in frequency domain which is fast.  Default is freq.

       speakers
           Set custom positions of virtual loudspeakers. Syntax for this option is: <CH> <AZIM> <ELEV>[|<CH> <AZIM> <ELEV>|...].
           Each virtual loudspeaker is described with short channel name following with azimuth and elevation in degrees.  Each
           virtual loudspeaker description is separated by '|'.  For example to override front left and front right channel
           positions use: 'speakers=FL 45 15|FR 345 15'.  Descriptions with unrecognised channel names are ignored.

       lfegain
           Set custom gain for LFE channels. Value is in dB. Default is 0.

       framesize
           Set custom frame size in number of samples. Default is 1024.  Allowed range is from 1024 to 96000. Only used if option
           type is set to freq.

       normalize
           Should all IRs be normalized upon importing SOFA file.  By default is enabled.

       interpolate
           Should nearest IRs be interpolated with neighbor IRs if exact position does not match. By default is disabled.

       minphase
           Minphase all IRs upon loading of SOFA file. By default is disabled.

       anglestep
           Set neighbor search angle step. Only used if option interpolate is enabled.

       radstep
           Set neighbor search radius step. Only used if option interpolate is enabled.

       Examples

       •   Using ClubFritz6 sofa file:

                   sofalizer=sofa=/path/to/ClubFritz6.sofa:type=freq:radius=1

       •   Using ClubFritz12 sofa file and bigger radius with small rotation:

                   sofalizer=sofa=/path/to/ClubFritz12.sofa:type=freq:radius=2:rotation=5

       •   Similar as above but with custom speaker positions for front left, front right, back left and back right and also with
           custom gain:

                   "sofalizer=sofa=/path/to/ClubFritz6.sofa:type=freq:radius=2:speakers=FL 45|FR 315|BL 135|BR 225:gain=28"

   speechnorm
       Speech Normalizer.

       This filter expands or compresses each half-cycle of audio samples (local set of samples all above or all below zero and
       between two nearest zero crossings) depending on threshold value, so audio reaches target peak value under conditions
       controlled by below options.

       The filter accepts the following options:

       peak, p
           Set the expansion target peak value. This specifies the highest allowed absolute amplitude level for the normalized
           audio input. Default value is 0.95. Allowed range is from 0.0 to 1.0.

       expansion, e
           Set the maximum expansion factor. Allowed range is from 1.0 to 50.0. Default value is 2.0.  This option controls maximum
           local half-cycle of samples expansion. The maximum expansion would be such that local peak value reaches target peak
           value but never to surpass it and that ratio between new and previous peak value does not surpass this option value.

       compression, c
           Set the maximum compression factor. Allowed range is from 1.0 to 50.0. Default value is 2.0.  This option controls
           maximum local half-cycle of samples compression. This option is used only if threshold option is set to value greater
           than 0.0, then in such cases when local peak is lower or same as value set by threshold all samples belonging to that
           peak's half-cycle will be compressed by current compression factor.

       threshold, t
           Set the threshold value. Default value is 0.0. Allowed range is from 0.0 to 1.0.  This option specifies which half-
           cycles of samples will be compressed and which will be expanded.  Any half-cycle samples with their local peak value
           below or same as this option value will be compressed by current compression factor, otherwise, if greater than
           threshold value they will be expanded with expansion factor so that it could reach peak target value but never surpass
           it.

       raise, r
           Set the expansion raising amount per each half-cycle of samples. Default value is 0.001.  Allowed range is from 0.0 to
           1.0. This controls how fast expansion factor is raised per each new half-cycle until it reaches expansion value.
           Setting this options too high may lead to distortions.

       fall, f
           Set the compression raising amount per each half-cycle of samples. Default value is 0.001.  Allowed range is from 0.0 to
           1.0. This controls how fast compression factor is raised per each new half-cycle until it reaches compression value.

       channels, h
           Specify which channels to filter, by default all available channels are filtered.

       invert, i
           Enable inverted filtering, by default is disabled. This inverts interpretation of threshold option. When enabled any
           half-cycle of samples with their local peak value below or same as threshold option will be expanded otherwise it will
           be compressed.

       link, l
           Link channels when calculating gain applied to each filtered channel sample, by default is disabled.  When disabled each
           filtered channel gain calculation is independent, otherwise when this option is enabled the minimum of all possible
           gains for each filtered channel is used.

       Commands

       This filter supports the all above options as commands.

   stereotools
       This filter has some handy utilities to manage stereo signals, for converting M/S stereo recordings to L/R signal while
       having control over the parameters or spreading the stereo image of master track.

       The filter accepts the following options:

       level_in
           Set input level before filtering for both channels. Defaults is 1.  Allowed range is from 0.015625 to 64.

       level_out
           Set output level after filtering for both channels. Defaults is 1.  Allowed range is from 0.015625 to 64.

       balance_in
           Set input balance between both channels. Default is 0.  Allowed range is from -1 to 1.

       balance_out
           Set output balance between both channels. Default is 0.  Allowed range is from -1 to 1.

       softclip
           Enable softclipping. Results in analog distortion instead of harsh digital 0dB clipping. Disabled by default.

       mutel
           Mute the left channel. Disabled by default.

       muter
           Mute the right channel. Disabled by default.

       phasel
           Change the phase of the left channel. Disabled by default.

       phaser
           Change the phase of the right channel. Disabled by default.

       mode
           Set stereo mode. Available values are:

           lr>lr
               Left/Right to Left/Right, this is default.

           lr>ms
               Left/Right to Mid/Side.

           ms>lr
               Mid/Side to Left/Right.

           lr>ll
               Left/Right to Left/Left.

           lr>rr
               Left/Right to Right/Right.

           lr>l+r
               Left/Right to Left + Right.

           lr>rl
               Left/Right to Right/Left.

           ms>ll
               Mid/Side to Left/Left.

           ms>rr
               Mid/Side to Right/Right.

           ms>rl
               Mid/Side to Right/Left.

           lr>l-r
               Left/Right to Left - Right.

       slev
           Set level of side signal. Default is 1.  Allowed range is from 0.015625 to 64.

       sbal
           Set balance of side signal. Default is 0.  Allowed range is from -1 to 1.

       mlev
           Set level of the middle signal. Default is 1.  Allowed range is from 0.015625 to 64.

       mpan
           Set middle signal pan. Default is 0. Allowed range is from -1 to 1.

       base
           Set stereo base between mono and inversed channels. Default is 0.  Allowed range is from -1 to 1.

       delay
           Set delay in milliseconds how much to delay left from right channel and vice versa. Default is 0. Allowed range is from
           -20 to 20.

       sclevel
           Set S/C level. Default is 1. Allowed range is from 1 to 100.

       phase
           Set the stereo phase in degrees. Default is 0. Allowed range is from 0 to 360.

       bmode_in, bmode_out
           Set balance mode for balance_in/balance_out option.

           Can be one of the following:

           balance
               Classic balance mode. Attenuate one channel at time.  Gain is raised up to 1.

           amplitude
               Similar as classic mode above but gain is raised up to 2.

           power
               Equal power distribution, from -6dB to +6dB range.

       Commands

       This filter supports the all above options as commands.

       Examples

       •   Apply karaoke like effect:

                   stereotools=mlev=0.015625

       •   Convert M/S signal to L/R:

                   "stereotools=mode=ms>lr"

   stereowiden
       This filter enhance the stereo effect by suppressing signal common to both channels and by delaying the signal of left into
       right and vice versa, thereby widening the stereo effect.

       The filter accepts the following options:

       delay
           Time in milliseconds of the delay of left signal into right and vice versa.  Default is 20 milliseconds.

       feedback
           Amount of gain in delayed signal into right and vice versa. Gives a delay effect of left signal in right output and vice
           versa which gives widening effect. Default is 0.3.

       crossfeed
           Cross feed of left into right with inverted phase. This helps in suppressing the mono. If the value is 1 it will cancel
           all the signal common to both channels. Default is 0.3.

       drymix
           Set level of input signal of original channel. Default is 0.8.

       Commands

       This filter supports the all above options except "delay" as commands.

   superequalizer
       Apply 18 band equalizer.

       The filter accepts the following options:

       1b  Set 65Hz band gain.

       2b  Set 92Hz band gain.

       3b  Set 131Hz band gain.

       4b  Set 185Hz band gain.

       5b  Set 262Hz band gain.

       6b  Set 370Hz band gain.

       7b  Set 523Hz band gain.

       8b  Set 740Hz band gain.

       9b  Set 1047Hz band gain.

       10b Set 1480Hz band gain.

       11b Set 2093Hz band gain.

       12b Set 2960Hz band gain.

       13b Set 4186Hz band gain.

       14b Set 5920Hz band gain.

       15b Set 8372Hz band gain.

       16b Set 11840Hz band gain.

       17b Set 16744Hz band gain.

       18b Set 20000Hz band gain.

   surround
       Apply audio surround upmix filter.

       This filter allows to produce multichannel output from audio stream.

       The filter accepts the following options:

       chl_out
           Set output channel layout. By default, this is 5.1.

           See the Channel Layout section in the ffmpeg-utils(1) manual for the required syntax.

       chl_in
           Set input channel layout. By default, this is stereo.

           See the Channel Layout section in the ffmpeg-utils(1) manual for the required syntax.

       level_in
           Set input volume level. By default, this is 1.

       level_out
           Set output volume level. By default, this is 1.

       lfe Enable LFE channel output if output channel layout has it. By default, this is enabled.

       lfe_low
           Set LFE low cut off frequency. By default, this is 128 Hz.

       lfe_high
           Set LFE high cut off frequency. By default, this is 256 Hz.

       lfe_mode
           Set LFE mode, can be add or sub. Default is add.  In add mode, LFE channel is created from input audio and added to
           output.  In sub mode, LFE channel is created from input audio and added to output but also all non-LFE output channels
           are subtracted with output LFE channel.

       angle
           Set angle of stereo surround transform, Allowed range is from 0 to 360.  Default is 90.

       fc_in
           Set front center input volume. By default, this is 1.

       fc_out
           Set front center output volume. By default, this is 1.

       fl_in
           Set front left input volume. By default, this is 1.

       fl_out
           Set front left output volume. By default, this is 1.

       fr_in
           Set front right input volume. By default, this is 1.

       fr_out
           Set front right output volume. By default, this is 1.

       sl_in
           Set side left input volume. By default, this is 1.

       sl_out
           Set side left output volume. By default, this is 1.

       sr_in
           Set side right input volume. By default, this is 1.

       sr_out
           Set side right output volume. By default, this is 1.

       bl_in
           Set back left input volume. By default, this is 1.

       bl_out
           Set back left output volume. By default, this is 1.

       br_in
           Set back right input volume. By default, this is 1.

       br_out
           Set back right output volume. By default, this is 1.

       bc_in
           Set back center input volume. By default, this is 1.

       bc_out
           Set back center output volume. By default, this is 1.

       lfe_in
           Set LFE input volume. By default, this is 1.

       lfe_out
           Set LFE output volume. By default, this is 1.

       allx
           Set spread usage of stereo image across X axis for all channels.  Allowed range is from -1 to 15.  By default this value
           is negative -1, and thus unused.

       ally
           Set spread usage of stereo image across Y axis for all channels.  Allowed range is from -1 to 15.  By default this value
           is negative -1, and thus unused.

       fcx, flx, frx, blx, brx, slx, srx, bcx
           Set spread usage of stereo image across X axis for each channel.  Allowed range is from 0.06 to 15.  By default this
           value is 0.5.

       fcy, fly, fry, bly, bry, sly, sry, bcy
           Set spread usage of stereo image across Y axis for each channel.  Allowed range is from 0.06 to 15.  By default this
           value is 0.5.

       win_size
           Set window size. Allowed range is from 1024 to 65536. Default size is 4096.

       win_func
           Set window function.

           It accepts the following values:

           rect
           bartlett
           hann, hanning
           hamming
           blackman
           welch
           flattop
           bharris
           bnuttall
           bhann
           sine
           nuttall
           lanczos
           gauss
           tukey
           dolph
           cauchy
           parzen
           poisson
           bohman

           Default is "hann".

       overlap
           Set window overlap. If set to 1, the recommended overlap for selected window function will be picked. Default is 0.5.

   tiltshelf
       Boost or cut the lower frequencies and cut or boost higher frequencies of the audio using a two-pole shelving filter with a
       response similar to that of a standard hi-fi's tone-controls.  This is also known as shelving equalisation (EQ).

       The filter accepts the following options:

       gain, g
           Give the gain at 0 Hz. Its useful range is about -20 (for a large cut) to +20 (for a large boost).  Beware of clipping
           when using a positive gain.

       frequency, f
           Set the filter's central frequency and so can be used to extend or reduce the frequency range to be boosted or cut.  The
           default value is 3000 Hz.

       width_type, t
           Set method to specify band-width of filter.

           h   Hz

           q   Q-Factor

           o   octave

           s   slope

           k   kHz

       width, w
           Determine how steep is the filter's shelf transition.

       poles, p
           Set number of poles. Default is 2.

       mix, m
           How much to use filtered signal in output. Default is 1.  Range is between 0 and 1.

       channels, c
           Specify which channels to filter, by default all available are filtered.

       normalize, n
           Normalize biquad coefficients, by default is disabled.  Enabling it will normalize magnitude response at DC to 0dB.

       transform, a
           Set transform type of IIR filter.

           di
           dii
           tdi
           tdii
           latt
           svf
           zdf
       precision, r
           Set precison of filtering.

           auto
               Pick automatic sample format depending on surround filters.

           s16 Always use signed 16-bit.

           s32 Always use signed 32-bit.

           f32 Always use float 32-bit.

           f64 Always use float 64-bit.

       block_size, b
           Set block size used for reverse IIR processing. If this value is set to high enough value (higher than impulse response
           length truncated when reaches near zero values) filtering will become linear phase otherwise if not big enough it will
           just produce nasty artifacts.

           Note that filter delay will be exactly this many samples when set to non-zero value.

       Commands

       This filter supports some options as commands.

   treble, highshelf
       Boost or cut treble (upper) frequencies of the audio using a two-pole shelving filter with a response similar to that of a
       standard hi-fi's tone-controls. This is also known as shelving equalisation (EQ).

       The filter accepts the following options:

       gain, g
           Give the gain at whichever is the lower of ~22 kHz and the Nyquist frequency. Its useful range is about -20 (for a large
           cut) to +20 (for a large boost). Beware of clipping when using a positive gain.

       frequency, f
           Set the filter's central frequency and so can be used to extend or reduce the frequency range to be boosted or cut.  The
           default value is 3000 Hz.

       width_type, t
           Set method to specify band-width of filter.

           h   Hz

           q   Q-Factor

           o   octave

           s   slope

           k   kHz

       width, w
           Determine how steep is the filter's shelf transition.

       poles, p
           Set number of poles. Default is 2.

       mix, m
           How much to use filtered signal in output. Default is 1.  Range is between 0 and 1.

       channels, c
           Specify which channels to filter, by default all available are filtered.

       normalize, n
           Normalize biquad coefficients, by default is disabled.  Enabling it will normalize magnitude response at DC to 0dB.

       transform, a
           Set transform type of IIR filter.

           di
           dii
           tdi
           tdii
           latt
           svf
           zdf
       precision, r
           Set precison of filtering.

           auto
               Pick automatic sample format depending on surround filters.

           s16 Always use signed 16-bit.

           s32 Always use signed 32-bit.

           f32 Always use float 32-bit.

           f64 Always use float 64-bit.

       block_size, b
           Set block size used for reverse IIR processing. If this value is set to high enough value (higher than impulse response
           length truncated when reaches near zero values) filtering will become linear phase otherwise if not big enough it will
           just produce nasty artifacts.

           Note that filter delay will be exactly this many samples when set to non-zero value.

       Commands

       This filter supports the following commands:

       frequency, f
           Change treble frequency.  Syntax for the command is : "frequency"

       width_type, t
           Change treble width_type.  Syntax for the command is : "width_type"

       width, w
           Change treble width.  Syntax for the command is : "width"

       gain, g
           Change treble gain.  Syntax for the command is : "gain"

       mix, m
           Change treble mix.  Syntax for the command is : "mix"

   tremolo
       Sinusoidal amplitude modulation.

       The filter accepts the following options:

       f   Modulation frequency in Hertz. Modulation frequencies in the subharmonic range (20 Hz or lower) will result in a tremolo
           effect.  This filter may also be used as a ring modulator by specifying a modulation frequency higher than 20 Hz.  Range
           is 0.1 - 20000.0. Default value is 5.0 Hz.

       d   Depth of modulation as a percentage. Range is 0.0 - 1.0.  Default value is 0.5.

   vibrato
       Sinusoidal phase modulation.

       The filter accepts the following options:

       f   Modulation frequency in Hertz.  Range is 0.1 - 20000.0. Default value is 5.0 Hz.

       d   Depth of modulation as a percentage. Range is 0.0 - 1.0.  Default value is 0.5.

   virtualbass
       Apply audio Virtual Bass filter.

       This filter accepts stereo input and produce stereo with LFE (2.1) channels output.  The newly produced LFE channel have
       enhanced virtual bass originally obtained from both stereo channels.  This filter outputs front left and front right
       channels unchanged as available in stereo input.

       The filter accepts the following options:

       cutoff
           Set the virtual bass cutoff frequency. Default value is 250 Hz.  Allowed range is from 100 to 500 Hz.

       strength
           Set the virtual bass strength. Allowed range is from 0.5 to 3.  Default value is 3.

   volume
       Adjust the input audio volume.

       It accepts the following parameters:

       volume
           Set audio volume expression.

           Output values are clipped to the maximum value.

           The output audio volume is given by the relation:

                   <output_volume> = <volume> * <input_volume>

           The default value for volume is "1.0".

       precision
           This parameter represents the mathematical precision.

           It determines which input sample formats will be allowed, which affects the precision of the volume scaling.

           fixed
               8-bit fixed-point; this limits input sample format to U8, S16, and S32.

           float
               32-bit floating-point; this limits input sample format to FLT. (default)

           double
               64-bit floating-point; this limits input sample format to DBL.

       replaygain
           Choose the behaviour on encountering ReplayGain side data in input frames.

           drop
               Remove ReplayGain side data, ignoring its contents (the default).

           ignore
               Ignore ReplayGain side data, but leave it in the frame.

           track
               Prefer the track gain, if present.

           album
               Prefer the album gain, if present.

       replaygain_preamp
           Pre-amplification gain in dB to apply to the selected replaygain gain.

           Default value for replaygain_preamp is 0.0.

       replaygain_noclip
           Prevent clipping by limiting the gain applied.

           Default value for replaygain_noclip is 1.

       eval
           Set when the volume expression is evaluated.

           It accepts the following values:

           once
               only evaluate expression once during the filter initialization, or when the volume command is sent

           frame
               evaluate expression for each incoming frame

           Default value is once.

       The volume expression can contain the following parameters.

       n   frame number (starting at zero)

       nb_channels
           number of channels

       nb_consumed_samples
           number of samples consumed by the filter

       nb_samples
           number of samples in the current frame

       pos original frame position in the file

       pts frame PTS

       sample_rate
           sample rate

       startpts
           PTS at start of stream

       startt
           time at start of stream

       t   frame time

       tb  timestamp timebase

       volume
           last set volume value

       Note that when eval is set to once only the sample_rate and tb variables are available, all other variables will evaluate to
       NAN.

       Commands

       This filter supports the following commands:

       volume
           Modify the volume expression.  The command accepts the same syntax of the corresponding option.

           If the specified expression is not valid, it is kept at its current value.

       Examples

       •   Halve the input audio volume:

                   volume=volume=0.5
                   volume=volume=1/2
                   volume=volume=-6.0206dB

           In all the above example the named key for volume can be omitted, for example like in:

                   volume=0.5

       •   Increase input audio power by 6 decibels using fixed-point precision:

                   volume=volume=6dB:precision=fixed

       •   Fade volume after time 10 with an annihilation period of 5 seconds:

                   volume='if(lt(t,10),1,max(1-(t-10)/5,0))':eval=frame

   volumedetect
       Detect the volume of the input video.

       The filter has no parameters. It supports only 16-bit signed integer samples, so the input will be converted when needed.
       Statistics about the volume will be printed in the log when the input stream end is reached.

       In particular it will show the mean volume (root mean square), maximum volume (on a per-sample basis), and the beginning of
       a histogram of the registered volume values (from the maximum value to a cumulated 1/1000 of the samples).

       All volumes are in decibels relative to the maximum PCM value.

       Examples

       Here is an excerpt of the output:

               [Parsed_volumedetect_0  0xa23120] mean_volume: -27 dB
               [Parsed_volumedetect_0  0xa23120] max_volume: -4 dB
               [Parsed_volumedetect_0  0xa23120] histogram_4db: 6
               [Parsed_volumedetect_0  0xa23120] histogram_5db: 62
               [Parsed_volumedetect_0  0xa23120] histogram_6db: 286
               [Parsed_volumedetect_0  0xa23120] histogram_7db: 1042
               [Parsed_volumedetect_0  0xa23120] histogram_8db: 2551
               [Parsed_volumedetect_0  0xa23120] histogram_9db: 4609
               [Parsed_volumedetect_0  0xa23120] histogram_10db: 8409

       It means that:

       •   The mean square energy is approximately -27 dB, or 10^-2.7.

       •   The largest sample is at -4 dB, or more precisely between -4 dB and -5 dB.

       •   There are 6 samples at -4 dB, 62 at -5 dB, 286 at -6 dB, etc.

       In other words, raising the volume by +4 dB does not cause any clipping, raising it by +5 dB causes clipping for 6 samples,
       etc.

AUDIO SOURCES
       Below is a description of the currently available audio sources.

   abuffer
       Buffer audio frames, and make them available to the filter chain.

       This source is mainly intended for a programmatic use, in particular through the interface defined in
       libavfilter/buffersrc.h.

       It accepts the following parameters:

       time_base
           The timebase which will be used for timestamps of submitted frames. It must be either a floating-point number or in
           numerator/denominator form.

       sample_rate
           The sample rate of the incoming audio buffers.

       sample_fmt
           The sample format of the incoming audio buffers.  Either a sample format name or its corresponding integer
           representation from the enum AVSampleFormat in libavutil/samplefmt.h

       channel_layout
           The channel layout of the incoming audio buffers.  Either a channel layout name from channel_layout_map in
           libavutil/channel_layout.c or its corresponding integer representation from the AV_CH_LAYOUT_* macros in
           libavutil/channel_layout.h

       channels
           The number of channels of the incoming audio buffers.  If both channels and channel_layout are specified, then they must
           be consistent.

       Examples

               abuffer=sample_rate=44100:sample_fmt=s16p:channel_layout=stereo

       will instruct the source to accept planar 16bit signed stereo at 44100Hz.  Since the sample format with name "s16p"
       corresponds to the number 6 and the "stereo" channel layout corresponds to the value 0x3, this is equivalent to:

               abuffer=sample_rate=44100:sample_fmt=6:channel_layout=0x3

   aevalsrc
       Generate an audio signal specified by an expression.

       This source accepts in input one or more expressions (one for each channel), which are evaluated and used to generate a
       corresponding audio signal.

       This source accepts the following options:

       exprs
           Set the '|'-separated expressions list for each separate channel. In case the channel_layout option is not specified,
           the selected channel layout depends on the number of provided expressions. Otherwise the last specified expression is
           applied to the remaining output channels.

       channel_layout, c
           Set the channel layout. The number of channels in the specified layout must be equal to the number of specified
           expressions.

       duration, d
           Set the minimum duration of the sourced audio. See the Time duration section in the ffmpeg-utils(1) manual for the
           accepted syntax.  Note that the resulting duration may be greater than the specified duration, as the generated audio is
           always cut at the end of a complete frame.

           If not specified, or the expressed duration is negative, the audio is supposed to be generated forever.

       nb_samples, n
           Set the number of samples per channel per each output frame, default to 1024.

       sample_rate, s
           Specify the sample rate, default to 44100.

       Each expression in exprs can contain the following constants:

       n   number of the evaluated sample, starting from 0

       t   time of the evaluated sample expressed in seconds, starting from 0

       s   sample rate

       Examples

       •   Generate silence:

                   aevalsrc=0

       •   Generate a sin signal with frequency of 440 Hz, set sample rate to 8000 Hz:

                   aevalsrc="sin(440*2*PI*t):s=8000"

       •   Generate a two channels signal, specify the channel layout (Front Center + Back Center) explicitly:

                   aevalsrc="sin(420*2*PI*t)|cos(430*2*PI*t):c=FC|BC"

       •   Generate white noise:

                   aevalsrc="-2+random(0)"

       •   Generate an amplitude modulated signal:

                   aevalsrc="sin(10*2*PI*t)*sin(880*2*PI*t)"

       •   Generate 2.5 Hz binaural beats on a 360 Hz carrier:

                   aevalsrc="0.1*sin(2*PI*(360-2.5/2)*t) | 0.1*sin(2*PI*(360+2.5/2)*t)"

   afirsrc
       Generate a FIR coefficients using frequency sampling method.

       The resulting stream can be used with afir filter for filtering the audio signal.

       The filter accepts the following options:

       taps, t
           Set number of filter coefficents in output audio stream.  Default value is 1025.

       frequency, f
           Set frequency points from where magnitude and phase are set.  This must be in non decreasing order, and first element
           must be 0, while last element must be 1. Elements are separated by white spaces.

       magnitude, m
           Set magnitude value for every frequency point set by frequency.  Number of values must be same as number of frequency
           points.  Values are separated by white spaces.

       phase, p
           Set phase value for every frequency point set by frequency.  Number of values must be same as number of frequency
           points.  Values are separated by white spaces.

       sample_rate, r
           Set sample rate, default is 44100.

       nb_samples, n
           Set number of samples per each frame. Default is 1024.

       win_func, w
           Set window function. Default is blackman.

   anullsrc
       The null audio source, return unprocessed audio frames. It is mainly useful as a template and to be employed in analysis /
       debugging tools, or as the source for filters which ignore the input data (for example the sox synth filter).

       This source accepts the following options:

       channel_layout, cl
           Specifies the channel layout, and can be either an integer or a string representing a channel layout. The default value
           of channel_layout is "stereo".

           Check the channel_layout_map definition in libavutil/channel_layout.c for the mapping between strings and channel layout
           values.

       sample_rate, r
           Specifies the sample rate, and defaults to 44100.

       nb_samples, n
           Set the number of samples per requested frames.

       duration, d
           Set the duration of the sourced audio. See the Time duration section in the ffmpeg-utils(1) manual for the accepted
           syntax.

           If not specified, or the expressed duration is negative, the audio is supposed to be generated forever.

       Examples

       •   Set the sample rate to 48000 Hz and the channel layout to AV_CH_LAYOUT_MONO.

                   anullsrc=r=48000:cl=4

       •   Do the same operation with a more obvious syntax:

                   anullsrc=r=48000:cl=mono

       All the parameters need to be explicitly defined.

   flite
       Synthesize a voice utterance using the libflite library.

       To enable compilation of this filter you need to configure FFmpeg with "--enable-libflite".

       Note that versions of the flite library prior to 2.0 are not thread-safe.

       The filter accepts the following options:

       list_voices
           If set to 1, list the names of the available voices and exit immediately. Default value is 0.

       nb_samples, n
           Set the maximum number of samples per frame. Default value is 512.

       textfile
           Set the filename containing the text to speak.

       text
           Set the text to speak.

       voice, v
           Set the voice to use for the speech synthesis. Default value is "kal". See also the list_voices option.

       Examples

       •   Read from file speech.txt, and synthesize the text using the standard flite voice:

                   flite=textfile=speech.txt

       •   Read the specified text selecting the "slt" voice:

                   flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt

       •   Input text to ffmpeg:

                   ffmpeg -f lavfi -i flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt

       •   Make ffplay speak the specified text, using "flite" and the "lavfi" device:

                   ffplay -f lavfi flite=text='No more be grieved for which that thou hast done.'

       For more information about libflite, check: <http://www.festvox.org/flite/>

   anoisesrc
       Generate a noise audio signal.

       The filter accepts the following options:

       sample_rate, r
           Specify the sample rate. Default value is 48000 Hz.

       amplitude, a
           Specify the amplitude (0.0 - 1.0) of the generated audio stream. Default value is 1.0.

       duration, d
           Specify the duration of the generated audio stream. Not specifying this option results in noise with an infinite length.

       color, colour, c
           Specify the color of noise. Available noise colors are white, pink, brown, blue, violet and velvet. Default color is
           white.

       seed, s
           Specify a value used to seed the PRNG.

       nb_samples, n
           Set the number of samples per each output frame, default is 1024.

       Examples

       •   Generate 60 seconds of pink noise, with a 44.1 kHz sampling rate and an amplitude of 0.5:

                   anoisesrc=d=60:c=pink:r=44100:a=0.5

   hilbert
       Generate odd-tap Hilbert transform FIR coefficients.

       The resulting stream can be used with afir filter for phase-shifting the signal by 90 degrees.

       This is used in many matrix coding schemes and for analytic signal generation.  The process is often written as a
       multiplication by i (or j), the imaginary unit.

       The filter accepts the following options:

       sample_rate, s
           Set sample rate, default is 44100.

       taps, t
           Set length of FIR filter, default is 22051.

       nb_samples, n
           Set number of samples per each frame.

       win_func, w
           Set window function to be used when generating FIR coefficients.

   sinc
       Generate a sinc kaiser-windowed low-pass, high-pass, band-pass, or band-reject FIR coefficients.

       The resulting stream can be used with afir filter for filtering the audio signal.

       The filter accepts the following options:

       sample_rate, r
           Set sample rate, default is 44100.

       nb_samples, n
           Set number of samples per each frame. Default is 1024.

       hp  Set high-pass frequency. Default is 0.

       lp  Set low-pass frequency. Default is 0.  If high-pass frequency is lower than low-pass frequency and low-pass frequency is
           higher than 0 then filter will create band-pass filter coefficients, otherwise band-reject filter coefficients.

       phase
           Set filter phase response. Default is 50. Allowed range is from 0 to 100.

       beta
           Set Kaiser window beta.

       att Set stop-band attenuation. Default is 120dB, allowed range is from 40 to 180 dB.

       round
           Enable rounding, by default is disabled.

       hptaps
           Set number of taps for high-pass filter.

       lptaps
           Set number of taps for low-pass filter.

   sine
       Generate an audio signal made of a sine wave with amplitude 1/8.

       The audio signal is bit-exact.

       The filter accepts the following options:

       frequency, f
           Set the carrier frequency. Default is 440 Hz.

       beep_factor, b
           Enable a periodic beep every second with frequency beep_factor times the carrier frequency. Default is 0, meaning the
           beep is disabled.

       sample_rate, r
           Specify the sample rate, default is 44100.

       duration, d
           Specify the duration of the generated audio stream.

       samples_per_frame
           Set the number of samples per output frame.

           The expression can contain the following constants:

           n   The (sequential) number of the output audio frame, starting from 0.

           pts The PTS (Presentation TimeStamp) of the output audio frame, expressed in TB units.

           t   The PTS of the output audio frame, expressed in seconds.

           TB  The timebase of the output audio frames.

           Default is 1024.

       Examples

       •   Generate a simple 440 Hz sine wave:

                   sine

       •   Generate a 220 Hz sine wave with a 880 Hz beep each second, for 5 seconds:

                   sine=220:4:d=5
                   sine=f=220:b=4:d=5
                   sine=frequency=220:beep_factor=4:duration=5

       •   Generate a 1 kHz sine wave following "1602,1601,1602,1601,1602" NTSC pattern:

                   sine=1000:samples_per_frame='st(0,mod(n,5)); 1602-not(not(eq(ld(0),1)+eq(ld(0),3)))'

AUDIO SINKS
       Below is a description of the currently available audio sinks.

   abuffersink
       Buffer audio frames, and make them available to the end of filter chain.

       This sink is mainly intended for programmatic use, in particular through the interface defined in libavfilter/buffersink.h
       or the options system.

       It accepts a pointer to an AVABufferSinkContext structure, which defines the incoming buffers' formats, to be passed as the
       opaque parameter to "avfilter_init_filter" for initialization.

   anullsink
       Null audio sink; do absolutely nothing with the input audio. It is mainly useful as a template and for use in analysis /
       debugging tools.

VIDEO FILTERS
       When you configure your FFmpeg build, you can disable any of the existing filters using "--disable-filters".  The configure
       output will show the video filters included in your build.

       Below is a description of the currently available video filters.

   addroi
       Mark a region of interest in a video frame.

       The frame data is passed through unchanged, but metadata is attached to the frame indicating regions of interest which can
       affect the behaviour of later encoding.  Multiple regions can be marked by applying the filter multiple times.

       x   Region distance in pixels from the left edge of the frame.

       y   Region distance in pixels from the top edge of the frame.

       w   Region width in pixels.

       h   Region height in pixels.

           The parameters x, y, w and h are expressions, and may contain the following variables:

           iw  Width of the input frame.

           ih  Height of the input frame.

       qoffset
           Quantisation offset to apply within the region.

           This must be a real value in the range -1 to +1.  A value of zero indicates no quality change.  A negative value asks
           for better quality (less quantisation), while a positive value asks for worse quality (greater quantisation).

           The range is calibrated so that the extreme values indicate the largest possible offset - if the rest of the frame is
           encoded with the worst possible quality, an offset of -1 indicates that this region should be encoded with the best
           possible quality anyway.  Intermediate values are then interpolated in some codec-dependent way.

           For example, in 10-bit H.264 the quantisation parameter varies between -12 and 51.  A typical qoffset value of -1/10
           therefore indicates that this region should be encoded with a QP around one-tenth of the full range better than the rest
           of the frame.  So, if most of the frame were to be encoded with a QP of around 30, this region would get a QP of around
           24 (an offset of approximately -1/10 * (51 - -12) = -6.3).  An extreme value of -1 would indicate that this region
           should be encoded with the best possible quality regardless of the treatment of the rest of the frame - that is, should
           be encoded at a QP of -12.

       clear
           If set to true, remove any existing regions of interest marked on the frame before adding the new one.

       Examples

       •   Mark the centre quarter of the frame as interesting.

                   addroi=iw/4:ih/4:iw/2:ih/2:-1/10

       •   Mark the 100-pixel-wide region on the left edge of the frame as very uninteresting (to be encoded at much lower quality
           than the rest of the frame).

                   addroi=0:0:100:ih:+1/5

   alphaextract
       Extract the alpha component from the input as a grayscale video. This is especially useful with the alphamerge filter.

   alphamerge
       Add or replace the alpha component of the primary input with the grayscale value of a second input. This is intended for use
       with alphaextract to allow the transmission or storage of frame sequences that have alpha in a format that doesn't support
       an alpha channel.

       For example, to reconstruct full frames from a normal YUV-encoded video and a separate video created with alphaextract, you
       might use:

               movie=in_alpha.mkv [alpha]; [in][alpha] alphamerge [out]

   amplify
       Amplify differences between current pixel and pixels of adjacent frames in same pixel location.

       This filter accepts the following options:

       radius
           Set frame radius. Default is 2. Allowed range is from 1 to 63.  For example radius of 3 will instruct filter to
           calculate average of 7 frames.

       factor
           Set factor to amplify difference. Default is 2. Allowed range is from 0 to 65535.

       threshold
           Set threshold for difference amplification. Any difference greater or equal to this value will not alter source pixel.
           Default is 10.  Allowed range is from 0 to 65535.

       tolerance
           Set tolerance for difference amplification. Any difference lower to this value will not alter source pixel. Default is
           0.  Allowed range is from 0 to 65535.

       low Set lower limit for changing source pixel. Default is 65535. Allowed range is from 0 to 65535.  This option controls
           maximum possible value that will decrease source pixel value.

       high
           Set high limit for changing source pixel. Default is 65535. Allowed range is from 0 to 65535.  This option controls
           maximum possible value that will increase source pixel value.

       planes
           Set which planes to filter. Default is all. Allowed range is from 0 to 15.

       Commands

       This filter supports the following commands that corresponds to option of same name:

       factor
       threshold
       tolerance
       low
       high
       planes

   ass
       Same as the subtitles filter, except that it doesn't require libavcodec and libavformat to work. On the other hand, it is
       limited to ASS (Advanced Substation Alpha) subtitles files.

       This filter accepts the following option in addition to the common options from the subtitles filter:

       shaping
           Set the shaping engine

           Available values are:

           auto
               The default libass shaping engine, which is the best available.

           simple
               Fast, font-agnostic shaper that can do only substitutions

           complex
               Slower shaper using OpenType for substitutions and positioning

           The default is "auto".

   atadenoise
       Apply an Adaptive Temporal Averaging Denoiser to the video input.

       The filter accepts the following options:

       0a  Set threshold A for 1st plane. Default is 0.02.  Valid range is 0 to 0.3.

       0b  Set threshold B for 1st plane. Default is 0.04.  Valid range is 0 to 5.

       1a  Set threshold A for 2nd plane. Default is 0.02.  Valid range is 0 to 0.3.

       1b  Set threshold B for 2nd plane. Default is 0.04.  Valid range is 0 to 5.

       2a  Set threshold A for 3rd plane. Default is 0.02.  Valid range is 0 to 0.3.

       2b  Set threshold B for 3rd plane. Default is 0.04.  Valid range is 0 to 5.

           Threshold A is designed to react on abrupt changes in the input signal and threshold B is designed to react on
           continuous changes in the input signal.

       s   Set number of frames filter will use for averaging. Default is 9. Must be odd number in range [5, 129].

       p   Set what planes of frame filter will use for averaging. Default is all.

       a   Set what variant of algorithm filter will use for averaging. Default is "p" parallel.  Alternatively can be set to "s"
           serial.

           Parallel can be faster then serial, while other way around is never true.  Parallel will abort early on first change
           being greater then thresholds, while serial will continue processing other side of frames if they are equal or below
           thresholds.

       0s
       1s
       2s  Set sigma for 1st plane, 2nd plane or 3rd plane. Default is 32767.  Valid range is from 0 to 32767.  This options
           controls weight for each pixel in radius defined by size.  Default value means every pixel have same weight.  Setting
           this option to 0 effectively disables filtering.

       Commands

       This filter supports same commands as options except option "s".  The command accepts the same syntax of the corresponding
       option.

   avgblur
       Apply average blur filter.

       The filter accepts the following options:

       sizeX
           Set horizontal radius size.

       planes
           Set which planes to filter. By default all planes are filtered.

       sizeY
           Set vertical radius size, if zero it will be same as "sizeX".  Default is 0.

       Commands

       This filter supports same commands as options.  The command accepts the same syntax of the corresponding option.

       If the specified expression is not valid, it is kept at its current value.

   bbox
       Compute the bounding box for the non-black pixels in the input frame luminance plane.

       This filter computes the bounding box containing all the pixels with a luminance value greater than the minimum allowed
       value.  The parameters describing the bounding box are printed on the filter log.

       The filter accepts the following option:

       min_val
           Set the minimal luminance value. Default is 16.

       Commands

       This filter supports the all above options as commands.

   bilateral
       Apply bilateral filter, spatial smoothing while preserving edges.

       The filter accepts the following options:

       sigmaS
           Set sigma of gaussian function to calculate spatial weight.  Allowed range is 0 to 512. Default is 0.1.

       sigmaR
           Set sigma of gaussian function to calculate range weight.  Allowed range is 0 to 1. Default is 0.1.

       planes
           Set planes to filter. Default is first only.

       Commands

       This filter supports the all above options as commands.

   bitplanenoise
       Show and measure bit plane noise.

       The filter accepts the following options:

       bitplane
           Set which plane to analyze. Default is 1.

       filter
           Filter out noisy pixels from "bitplane" set above.  Default is disabled.

   blackdetect
       Detect video intervals that are (almost) completely black. Can be useful to detect chapter transitions, commercials, or
       invalid recordings.

       The filter outputs its detection analysis to both the log as well as frame metadata. If a black segment of at least the
       specified minimum duration is found, a line with the start and end timestamps as well as duration is printed to the log with
       level "info". In addition, a log line with level "debug" is printed per frame showing the black amount detected for that
       frame.

       The filter also attaches metadata to the first frame of a black segment with key "lavfi.black_start" and to the first frame
       after the black segment ends with key "lavfi.black_end". The value is the frame's timestamp. This metadata is added
       regardless of the minimum duration specified.

       The filter accepts the following options:

       black_min_duration, d
           Set the minimum detected black duration expressed in seconds. It must be a non-negative floating point number.

           Default value is 2.0.

       picture_black_ratio_th, pic_th
           Set the threshold for considering a picture "black".  Express the minimum value for the ratio:

                   <nb_black_pixels> / <nb_pixels>

           for which a picture is considered black.  Default value is 0.98.

       pixel_black_th, pix_th
           Set the threshold for considering a pixel "black".

           The threshold expresses the maximum pixel luminance value for which a pixel is considered "black". The provided value is
           scaled according to the following equation:

                   <absolute_threshold> = <luminance_minimum_value> + <pixel_black_th> * <luminance_range_size>

           luminance_range_size and luminance_minimum_value depend on the input video format, the range is [0-255] for YUV full-
           range formats and [16-235] for YUV non full-range formats.

           Default value is 0.10.

       The following example sets the maximum pixel threshold to the minimum value, and detects only black intervals of 2 or more
       seconds:

               blackdetect=d=2:pix_th=0.00

   blackframe
       Detect frames that are (almost) completely black. Can be useful to detect chapter transitions or commercials. Output lines
       consist of the frame number of the detected frame, the percentage of blackness, the position in the file if known or -1 and
       the timestamp in seconds.

       In order to display the output lines, you need to set the loglevel at least to the AV_LOG_INFO value.

       This filter exports frame metadata "lavfi.blackframe.pblack".  The value represents the percentage of pixels in the picture
       that are below the threshold value.

       It accepts the following parameters:

       amount
           The percentage of the pixels that have to be below the threshold; it defaults to 98.

       threshold, thresh
           The threshold below which a pixel value is considered black; it defaults to 32.

   blend
       Blend two video frames into each other.

       The "blend" filter takes two input streams and outputs one stream, the first input is the "top" layer and second input is
       "bottom" layer.  By default, the output terminates when the longest input terminates.

       The "tblend" (time blend) filter takes two consecutive frames from one single stream, and outputs the result obtained by
       blending the new frame on top of the old frame.

       A description of the accepted options follows.

       c0_mode
       c1_mode
       c2_mode
       c3_mode
       all_mode
           Set blend mode for specific pixel component or all pixel components in case of all_mode. Default value is "normal".

           Available values for component modes are:

           addition
           and
           average
           bleach
           burn
           darken
           difference
           divide
           dodge
           exclusion
           extremity
           freeze
           geometric
           glow
           grainextract
           grainmerge
           hardlight
           hardmix
           hardoverlay
           harmonic
           heat
           interpolate
           lighten
           linearlight
           multiply
           multiply128
           negation
           normal
           or
           overlay
           phoenix
           pinlight
           reflect
           screen
           softdifference
           softlight
           stain
           subtract
           vividlight
           xor
       c0_opacity
       c1_opacity
       c2_opacity
       c3_opacity
       all_opacity
           Set blend opacity for specific pixel component or all pixel components in case of all_opacity. Only used in combination
           with pixel component blend modes.

       c0_expr
       c1_expr
       c2_expr
       c3_expr
       all_expr
           Set blend expression for specific pixel component or all pixel components in case of all_expr. Note that related mode
           options will be ignored if those are set.

           The expressions can use the following variables:

           N   The sequential number of the filtered frame, starting from 0.

           X
           Y   the coordinates of the current sample

           W
           H   the width and height of currently filtered plane

           SW
           SH  Width and height scale for the plane being filtered. It is the ratio between the dimensions of the current plane to
               the luma plane, e.g. for a "yuv420p" frame, the values are "1,1" for the luma plane and "0.5,0.5" for the chroma
               planes.

           T   Time of the current frame, expressed in seconds.

           TOP, A
               Value of pixel component at current location for first video frame (top layer).

           BOTTOM, B
               Value of pixel component at current location for second video frame (bottom layer).

       The "blend" filter also supports the framesync options.

       Examples

       •   Apply transition from bottom layer to top layer in first 10 seconds:

                   blend=all_expr='A*(if(gte(T,10),1,T/10))+B*(1-(if(gte(T,10),1,T/10)))'

       •   Apply linear horizontal transition from top layer to bottom layer:

                   blend=all_expr='A*(X/W)+B*(1-X/W)'

       •   Apply 1x1 checkerboard effect:

                   blend=all_expr='if(eq(mod(X,2),mod(Y,2)),A,B)'

       •   Apply uncover left effect:

                   blend=all_expr='if(gte(N*SW+X,W),A,B)'

       •   Apply uncover down effect:

                   blend=all_expr='if(gte(Y-N*SH,0),A,B)'

       •   Apply uncover up-left effect:

                   blend=all_expr='if(gte(T*SH*40+Y,H)*gte((T*40*SW+X)*W/H,W),A,B)'

       •   Split diagonally video and shows top and bottom layer on each side:

                   blend=all_expr='if(gt(X,Y*(W/H)),A,B)'

       •   Display differences between the current and the previous frame:

                   tblend=all_mode=grainextract

       Commands

       This filter supports same commands as options.

   blockdetect
       Determines blockiness of frames without altering the input frames.

       Based on Remco Muijs and Ihor Kirenko: "A no-reference blocking artifact measure for adaptive video processing." 2005 13th
       European signal processing conference.

       The filter accepts the following options:

       period_min
       period_max
           Set minimum and maximum values for determining pixel grids (periods).  Default values are [3,24].

       planes
           Set planes to filter. Default is first only.

       Examples

       •   Determine blockiness for the first plane and search for periods within [8,32]:

                   blockdetect=period_min=8:period_max=32:planes=1

   blurdetect
       Determines blurriness of frames without altering the input frames.

       Based on Marziliano, Pina, et al. "A no-reference perceptual blur metric."  Allows for a block-based abbreviation.

       The filter accepts the following options:

       low
       high
           Set low and high threshold values used by the Canny thresholding algorithm.

           The high threshold selects the "strong" edge pixels, which are then connected through 8-connectivity with the "weak"
           edge pixels selected by the low threshold.

           low and high threshold values must be chosen in the range [0,1], and low should be lesser or equal to high.

           Default value for low is "20/255", and default value for high is "50/255".

       radius
           Define the radius to search around an edge pixel for local maxima.

       block_pct
           Determine blurriness only for the most significant blocks, given in percentage.

       block_width
           Determine blurriness for blocks of width block_width. If set to any value smaller 1, no blocks are used and the whole
           image is processed as one no matter of block_height.

       block_height
           Determine blurriness for blocks of height block_height. If set to any value smaller 1, no blocks are used and the whole
           image is processed as one no matter of block_width.

       planes
           Set planes to filter. Default is first only.

       Examples

       •   Determine blur for 80% of most significant 32x32 blocks:

                   blurdetect=block_width=32:block_height=32:block_pct=80

   bm3d
       Denoise frames using Block-Matching 3D algorithm.

       The filter accepts the following options.

       sigma
           Set denoising strength. Default value is 1.  Allowed range is from 0 to 999.9.  The denoising algorithm is very
           sensitive to sigma, so adjust it according to the source.

       block
           Set local patch size. This sets dimensions in 2D.

       bstep
           Set sliding step for processing blocks. Default value is 4.  Allowed range is from 1 to 64.  Smaller values allows
           processing more reference blocks and is slower.

       group
           Set maximal number of similar blocks for 3rd dimension. Default value is 1.  When set to 1, no block matching is done.
           Larger values allows more blocks in single group.  Allowed range is from 1 to 256.

       range
           Set radius for search block matching. Default is 9.  Allowed range is from 1 to INT32_MAX.

       mstep
           Set step between two search locations for block matching. Default is 1.  Allowed range is from 1 to 64. Smaller is
           slower.

       thmse
           Set threshold of mean square error for block matching. Valid range is 0 to INT32_MAX.

       hdthr
           Set thresholding parameter for hard thresholding in 3D transformed domain.  Larger values results in stronger hard-
           thresholding filtering in frequency domain.

       estim
           Set filtering estimation mode. Can be "basic" or "final".  Default is "basic".

       ref If enabled, filter will use 2nd stream for block matching.  Default is disabled for "basic" value of estim option, and
           always enabled if value of estim is "final".

       planes
           Set planes to filter. Default is all available except alpha.

       Examples

       •   Basic filtering with bm3d:

                   bm3d=sigma=3:block=4:bstep=2:group=1:estim=basic

       •   Same as above, but filtering only luma:

                   bm3d=sigma=3:block=4:bstep=2:group=1:estim=basic:planes=1

       •   Same as above, but with both estimation modes:

                   split[a][b],[a]bm3d=sigma=3:block=4:bstep=2:group=1:estim=basic[a],[b][a]bm3d=sigma=3:block=4:bstep=2:group=16:estim=final:ref=1

       •   Same as above, but prefilter with nlmeans filter instead:

                   split[a][b],[a]nlmeans=s=3:r=7:p=3[a],[b][a]bm3d=sigma=3:block=4:bstep=2:group=16:estim=final:ref=1

   boxblur
       Apply a boxblur algorithm to the input video.

       It accepts the following parameters:

       luma_radius, lr
       luma_power, lp
       chroma_radius, cr
       chroma_power, cp
       alpha_radius, ar
       alpha_power, ap

       A description of the accepted options follows.

       luma_radius, lr
       chroma_radius, cr
       alpha_radius, ar
           Set an expression for the box radius in pixels used for blurring the corresponding input plane.

           The radius value must be a non-negative number, and must not be greater than the value of the expression "min(w,h)/2"
           for the luma and alpha planes, and of "min(cw,ch)/2" for the chroma planes.

           Default value for luma_radius is "2". If not specified, chroma_radius and alpha_radius default to the corresponding
           value set for luma_radius.

           The expressions can contain the following constants:

           w
           h   The input width and height in pixels.

           cw
           ch  The input chroma image width and height in pixels.

           hsub
           vsub
               The horizontal and vertical chroma subsample values. For example, for the pixel format "yuv422p", hsub is 2 and vsub
               is 1.

       luma_power, lp
       chroma_power, cp
       alpha_power, ap
           Specify how many times the boxblur filter is applied to the corresponding plane.

           Default value for luma_power is 2. If not specified, chroma_power and alpha_power default to the corresponding value set
           for luma_power.

           A value of 0 will disable the effect.

       Examples

       •   Apply a boxblur filter with the luma, chroma, and alpha radii set to 2:

                   boxblur=luma_radius=2:luma_power=1
                   boxblur=2:1

       •   Set the luma radius to 2, and alpha and chroma radius to 0:

                   boxblur=2:1:cr=0:ar=0

       •   Set the luma and chroma radii to a fraction of the video dimension:

                   boxblur=luma_radius=min(h\,w)/10:luma_power=1:chroma_radius=min(cw\,ch)/10:chroma_power=1

   bwdif
       Deinterlace the input video ("bwdif" stands for "Bob Weaver Deinterlacing Filter").

       Motion adaptive deinterlacing based on yadif with the use of w3fdif and cubic interpolation algorithms.  It accepts the
       following parameters:

       mode
           The interlacing mode to adopt. It accepts one of the following values:

           0, send_frame
               Output one frame for each frame.

           1, send_field
               Output one frame for each field.

           The default value is "send_field".

       parity
           The picture field parity assumed for the input interlaced video. It accepts one of the following values:

           0, tff
               Assume the top field is first.

           1, bff
               Assume the bottom field is first.

           -1, auto
               Enable automatic detection of field parity.

           The default value is "auto".  If the interlacing is unknown or the decoder does not export this information, top field
           first will be assumed.

       deint
           Specify which frames to deinterlace. Accepts one of the following values:

           0, all
               Deinterlace all frames.

           1, interlaced
               Only deinterlace frames marked as interlaced.

           The default value is "all".

   cas
       Apply Contrast Adaptive Sharpen filter to video stream.

       The filter accepts the following options:

       strength
           Set the sharpening strength. Default value is 0.

       planes
           Set planes to filter. Default value is to filter all planes except alpha plane.

       Commands

       This filter supports same commands as options.

   chromahold
       Remove all color information for all colors except for certain one.

       The filter accepts the following options:

       color
           The color which will not be replaced with neutral chroma.

       similarity
           Similarity percentage with the above color.  0.01 matches only the exact key color, while 1.0 matches everything.

       blend
           Blend percentage.  0.0 makes pixels either fully gray, or not gray at all.  Higher values result in more preserved
           color.

       yuv Signals that the color passed is already in YUV instead of RGB.

           Literal colors like "green" or "red" don't make sense with this enabled anymore.  This can be used to pass exact YUV
           values as hexadecimal numbers.

       Commands

       This filter supports same commands as options.  The command accepts the same syntax of the corresponding option.

       If the specified expression is not valid, it is kept at its current value.

   chromakey
       YUV colorspace color/chroma keying.

       The filter accepts the following options:

       color
           The color which will be replaced with transparency.

       similarity
           Similarity percentage with the key color.

           0.01 matches only the exact key color, while 1.0 matches everything.

       blend
           Blend percentage.

           0.0 makes pixels either fully transparent, or not transparent at all.

           Higher values result in semi-transparent pixels, with a higher transparency the more similar the pixels color is to the
           key color.

       yuv Signals that the color passed is already in YUV instead of RGB.

           Literal colors like "green" or "red" don't make sense with this enabled anymore.  This can be used to pass exact YUV
           values as hexadecimal numbers.

       Commands

       This filter supports same commands as options.  The command accepts the same syntax of the corresponding option.

       If the specified expression is not valid, it is kept at its current value.

       Examples

       •   Make every green pixel in the input image transparent:

                   ffmpeg -i input.png -vf chromakey=green out.png

       •   Overlay a greenscreen-video on top of a static black background.

                   ffmpeg -f lavfi -i color=c=black:s=1280x720 -i video.mp4 -shortest -filter_complex "[1:v]chromakey=0x70de77:0.1:0.2[ckout];[0:v][ckout]overlay[out]" -map "[out]" output.mkv

   chromakey_cuda
       CUDA accelerated YUV colorspace color/chroma keying.

       This filter works like normal chromakey filter but operates on CUDA frames.  for more details and parameters see chromakey.

       Examples

       •   Make all the green pixels in the input video transparent and use it as an overlay for another video:

                   ./ffmpeg \
                       -hwaccel cuda -hwaccel_output_format cuda -i input_green.mp4  \
                       -hwaccel cuda -hwaccel_output_format cuda -i base_video.mp4 \
                       -init_hw_device cuda \
                       -filter_complex \
                       " \
                           [0:v]chromakey_cuda=0x25302D:0.1:0.12:1[overlay_video]; \
                           [1:v]scale_cuda=format=yuv420p[base]; \
                           [base][overlay_video]overlay_cuda" \
                       -an -sn -c:v h264_nvenc -cq 20 output.mp4

       •   Process two software sources, explicitly uploading the frames:

                   ./ffmpeg -init_hw_device cuda=cuda -filter_hw_device cuda \
                       -f lavfi -i color=size=800x600:color=white,format=yuv420p \
                       -f lavfi -i yuvtestsrc=size=200x200,format=yuv420p \
                       -filter_complex \
                       " \
                           [0]hwupload[under]; \
                           [1]hwupload,chromakey_cuda=green:0.1:0.12[over]; \
                           [under][over]overlay_cuda" \
                       -c:v hevc_nvenc -cq 18 -preset slow output.mp4

   chromanr
       Reduce chrominance noise.

       The filter accepts the following options:

       thres
           Set threshold for averaging chrominance values.  Sum of absolute difference of Y, U and V pixel components of current
           pixel and neighbour pixels lower than this threshold will be used in averaging. Luma component is left unchanged and is
           copied to output.  Default value is 30. Allowed range is from 1 to 200.

       sizew
           Set horizontal radius of rectangle used for averaging.  Allowed range is from 1 to 100. Default value is 5.

       sizeh
           Set vertical radius of rectangle used for averaging.  Allowed range is from 1 to 100. Default value is 5.

       stepw
           Set horizontal step when averaging. Default value is 1.  Allowed range is from 1 to 50.  Mostly useful to speed-up
           filtering.

       steph
           Set vertical step when averaging. Default value is 1.  Allowed range is from 1 to 50.  Mostly useful to speed-up
           filtering.

       threy
           Set Y threshold for averaging chrominance values.  Set finer control for max allowed difference between Y components of
           current pixel and neigbour pixels.  Default value is 200. Allowed range is from 1 to 200.

       threu
           Set U threshold for averaging chrominance values.  Set finer control for max allowed difference between U components of
           current pixel and neigbour pixels.  Default value is 200. Allowed range is from 1 to 200.

       threv
           Set V threshold for averaging chrominance values.  Set finer control for max allowed difference between V components of
           current pixel and neigbour pixels.  Default value is 200. Allowed range is from 1 to 200.

       distance
           Set distance type used in calculations.

           manhattan
               Absolute difference.

           euclidean
               Difference squared.

           Default distance type is manhattan.

       Commands

       This filter supports same commands as options.  The command accepts the same syntax of the corresponding option.

   chromashift
       Shift chroma pixels horizontally and/or vertically.

       The filter accepts the following options:

       cbh Set amount to shift chroma-blue horizontally.

       cbv Set amount to shift chroma-blue vertically.

       crh Set amount to shift chroma-red horizontally.

       crv Set amount to shift chroma-red vertically.

       edge
           Set edge mode, can be smear, default, or warp.

       Commands

       This filter supports the all above options as commands.

   ciescope
       Display CIE color diagram with pixels overlaid onto it.

       The filter accepts the following options:

       system
           Set color system.

           ntsc, 470m
           ebu, 470bg
           smpte
           240m
           apple
           widergb
           cie1931
           rec709, hdtv
           uhdtv, rec2020
           dcip3
       cie Set CIE system.

           xyy
           ucs
           luv
       gamuts
           Set what gamuts to draw.

           See "system" option for available values.

       size, s
           Set ciescope size, by default set to 512.

       intensity, i
           Set intensity used to map input pixel values to CIE diagram.

       contrast
           Set contrast used to draw tongue colors that are out of active color system gamut.

       corrgamma
           Correct gamma displayed on scope, by default enabled.

       showwhite
           Show white point on CIE diagram, by default disabled.

       gamma
           Set input gamma. Used only with XYZ input color space.

       fill
           Fill with CIE colors. By default is enabled.

   codecview
       Visualize information exported by some codecs.

       Some codecs can export information through frames using side-data or other means. For example, some MPEG based codecs export
       motion vectors through the export_mvs flag in the codec flags2 option.

       The filter accepts the following option:

       block
           Display block partition structure using the luma plane.

       mv  Set motion vectors to visualize.

           Available flags for mv are:

           pf  forward predicted MVs of P-frames

           bf  forward predicted MVs of B-frames

           bb  backward predicted MVs of B-frames

       qp  Display quantization parameters using the chroma planes.

       mv_type, mvt
           Set motion vectors type to visualize. Includes MVs from all frames unless specified by frame_type option.

           Available flags for mv_type are:

           fp  forward predicted MVs

           bp  backward predicted MVs

       frame_type, ft
           Set frame type to visualize motion vectors of.

           Available flags for frame_type are:

           if  intra-coded frames (I-frames)

           pf  predicted frames (P-frames)

           bf  bi-directionally predicted frames (B-frames)

       Examples

       •   Visualize forward predicted MVs of all frames using ffplay:

                   ffplay -flags2 +export_mvs input.mp4 -vf codecview=mv_type=fp

       •   Visualize multi-directionals MVs of P and B-Frames using ffplay:

                   ffplay -flags2 +export_mvs input.mp4 -vf codecview=mv=pf+bf+bb

   colorbalance
       Modify intensity of primary colors (red, green and blue) of input frames.

       The filter allows an input frame to be adjusted in the shadows, midtones or highlights regions for the red-cyan, green-
       magenta or blue-yellow balance.

       A positive adjustment value shifts the balance towards the primary color, a negative value towards the complementary color.

       The filter accepts the following options:

       rs
       gs
       bs  Adjust red, green and blue shadows (darkest pixels).

       rm
       gm
       bm  Adjust red, green and blue midtones (medium pixels).

       rh
       gh
       bh  Adjust red, green and blue highlights (brightest pixels).

           Allowed ranges for options are "[-1.0, 1.0]". Defaults are 0.

       pl  Preserve lightness when changing color balance. Default is disabled.

       Examples

       •   Add red color cast to shadows:

                   colorbalance=rs=.3

       Commands

       This filter supports the all above options as commands.

   colorcontrast
       Adjust color contrast between RGB components.

       The filter accepts the following options:

       rc  Set the red-cyan contrast. Defaults is 0.0. Allowed range is from -1.0 to 1.0.

       gm  Set the green-magenta contrast. Defaults is 0.0. Allowed range is from -1.0 to 1.0.

       by  Set the blue-yellow contrast. Defaults is 0.0. Allowed range is from -1.0 to 1.0.

       rcw
       gmw
       byw Set the weight of each "rc", "gm", "by" option value. Default value is 0.0.  Allowed range is from 0.0 to 1.0. If all
           weights are 0.0 filtering is disabled.

       pl  Set the amount of preserving lightness. Default value is 0.0. Allowed range is from 0.0 to 1.0.

       Commands

       This filter supports the all above options as commands.

   colorcorrect
       Adjust color white balance selectively for blacks and whites.  This filter operates in YUV colorspace.

       The filter accepts the following options:

       rl  Set the red shadow spot. Allowed range is from -1.0 to 1.0.  Default value is 0.

       bl  Set the blue shadow spot. Allowed range is from -1.0 to 1.0.  Default value is 0.

       rh  Set the red highlight spot. Allowed range is from -1.0 to 1.0.  Default value is 0.

       bh  Set the red highlight spot. Allowed range is from -1.0 to 1.0.  Default value is 0.

       saturation
           Set the amount of saturation. Allowed range is from -3.0 to 3.0.  Default value is 1.

       analyze
           If set to anything other than "manual" it will analyze every frame and use derived parameters for filtering output
           frame.

           Possible values are:

           manual
           average
           minmax
           median

           Default value is "manual".

       Commands

       This filter supports the all above options as commands.

   colorchannelmixer
       Adjust video input frames by re-mixing color channels.

       This filter modifies a color channel by adding the values associated to the other channels of the same pixels. For example
       if the value to modify is red, the output value will be:

               <red>=<red>*<rr> + <blue>*<rb> + <green>*<rg> + <alpha>*<ra>

       The filter accepts the following options:

       rr
       rg
       rb
       ra  Adjust contribution of input red, green, blue and alpha channels for output red channel.  Default is 1 for rr, and 0 for
           rg, rb and ra.

       gr
       gg
       gb
       ga  Adjust contribution of input red, green, blue and alpha channels for output green channel.  Default is 1 for gg, and 0
           for gr, gb and ga.

       br
       bg
       bb
       ba  Adjust contribution of input red, green, blue and alpha channels for output blue channel.  Default is 1 for bb, and 0
           for br, bg and ba.

       ar
       ag
       ab
       aa  Adjust contribution of input red, green, blue and alpha channels for output alpha channel.  Default is 1 for aa, and 0
           for ar, ag and ab.

           Allowed ranges for options are "[-2.0, 2.0]".

       pc  Set preserve color mode. The accepted values are:

           none
               Disable color preserving, this is default.

           lum Preserve luminance.

           max Preserve max value of RGB triplet.

           avg Preserve average value of RGB triplet.

           sum Preserve sum value of RGB triplet.

           nrm Preserve normalized value of RGB triplet.

           pwr Preserve power value of RGB triplet.

       pa  Set the preserve color amount when changing colors. Allowed range is from "[0.0, 1.0]".  Default is 0.0, thus disabled.

       Examples

       •   Convert source to grayscale:

                   colorchannelmixer=.3:.4:.3:0:.3:.4:.3:0:.3:.4:.3

       •   Simulate sepia tones:

                   colorchannelmixer=.393:.769:.189:0:.349:.686:.168:0:.272:.534:.131

       Commands

       This filter supports the all above options as commands.

   colorize
       Overlay a solid color on the video stream.

       The filter accepts the following options:

       hue Set the color hue. Allowed range is from 0 to 360.  Default value is 0.

       saturation
           Set the color saturation. Allowed range is from 0 to 1.  Default value is 0.5.

       lightness
           Set the color lightness. Allowed range is from 0 to 1.  Default value is 0.5.

       mix Set the mix of source lightness. By default is set to 1.0.  Allowed range is from 0.0 to 1.0.

       Commands

       This filter supports the all above options as commands.

   colorkey
       RGB colorspace color keying.  This filter operates on 8-bit RGB format frames by setting the alpha component of each pixel
       which falls within the similarity radius of the key color to 0. The alpha value for pixels outside the similarity radius
       depends on the value of the blend option.

       The filter accepts the following options:

       color
           Set the color for which alpha will be set to 0 (full transparency).  See "Color" section in the ffmpeg-utils manual.
           Default is "black".

       similarity
           Set the radius from the key color within which other colors also have full transparency.  The computed distance is
           related to the unit fractional distance in 3D space between the RGB values of the key color and the pixel's color. Range
           is 0.01 to 1.0. 0.01 matches within a very small radius around the exact key color, while 1.0 matches everything.
           Default is 0.01.

       blend
           Set how the alpha value for pixels that fall outside the similarity radius is computed.  0.0 makes pixels either fully
           transparent or fully opaque.  Higher values result in semi-transparent pixels, with greater transparency the more
           similar the pixel color is to the key color.  Range is 0.0 to 1.0. Default is 0.0.

       Examples

       •   Make every green pixel in the input image transparent:

                   ffmpeg -i input.png -vf colorkey=green out.png

       •   Overlay a greenscreen-video on top of a static background image.

                   ffmpeg -i background.png -i video.mp4 -filter_complex "[1:v]colorkey=0x3BBD1E:0.3:0.2[ckout];[0:v][ckout]overlay[out]" -map "[out]" output.flv

       Commands

       This filter supports same commands as options.  The command accepts the same syntax of the corresponding option.

       If the specified expression is not valid, it is kept at its current value.

   colorhold
       Remove all color information for all RGB colors except for certain one.

       The filter accepts the following options:

       color
           The color which will not be replaced with neutral gray.

       similarity
           Similarity percentage with the above color.  0.01 matches only the exact key color, while 1.0 matches everything.

       blend
           Blend percentage. 0.0 makes pixels fully gray.  Higher values result in more preserved color.

       Commands

       This filter supports same commands as options.  The command accepts the same syntax of the corresponding option.

       If the specified expression is not valid, it is kept at its current value.

   colorlevels
       Adjust video input frames using levels.

       The filter accepts the following options:

       rimin
       gimin
       bimin
       aimin
           Adjust red, green, blue and alpha input black point.  Allowed ranges for options are "[-1.0, 1.0]". Defaults are 0.

       rimax
       gimax
       bimax
       aimax
           Adjust red, green, blue and alpha input white point.  Allowed ranges for options are "[-1.0, 1.0]". Defaults are 1.

           Input levels are used to lighten highlights (bright tones), darken shadows (dark tones), change the balance of bright
           and dark tones.

       romin
       gomin
       bomin
       aomin
           Adjust red, green, blue and alpha output black point.  Allowed ranges for options are "[0, 1.0]". Defaults are 0.

       romax
       gomax
       bomax
       aomax
           Adjust red, green, blue and alpha output white point.  Allowed ranges for options are "[0, 1.0]". Defaults are 1.

           Output levels allows manual selection of a constrained output level range.

       preserve
           Set preserve color mode. The accepted values are:

           none
               Disable color preserving, this is default.

           lum Preserve luminance.

           max Preserve max value of RGB triplet.

           avg Preserve average value of RGB triplet.

           sum Preserve sum value of RGB triplet.

           nrm Preserve normalized value of RGB triplet.

           pwr Preserve power value of RGB triplet.

       Examples

       •   Make video output darker:

                   colorlevels=rimin=0.058:gimin=0.058:bimin=0.058

       •   Increase contrast:

                   colorlevels=rimin=0.039:gimin=0.039:bimin=0.039:rimax=0.96:gimax=0.96:bimax=0.96

       •   Make video output lighter:

                   colorlevels=rimax=0.902:gimax=0.902:bimax=0.902

       •   Increase brightness:

                   colorlevels=romin=0.5:gomin=0.5:bomin=0.5

       Commands

       This filter supports the all above options as commands.

   colormap
       Apply custom color maps to video stream.

       This filter needs three input video streams.  First stream is video stream that is going to be filtered out.  Second and
       third video stream specify color patches for source color to target color mapping.

       The filter accepts the following options:

       patch_size
           Set the source and target video stream patch size in pixels.

       nb_patches
           Set the max number of used patches from source and target video stream.  Default value is number of patches available in
           additional video streams.  Max allowed number of patches is 64.

       type
           Set the adjustments used for target colors. Can be "relative" or "absolute".  Defaults is "absolute".

       kernel
           Set the kernel used to measure color differences between mapped colors.

           The accepted values are:

           euclidean
           weuclidean

           Default is "euclidean".

   colormatrix
       Convert color matrix.

       The filter accepts the following options:

       src
       dst Specify the source and destination color matrix. Both values must be specified.

           The accepted values are:

           bt709
               BT.709

           fcc FCC

           bt601
               BT.601

           bt470
               BT.470

           bt470bg
               BT.470BG

           smpte170m
               SMPTE-170M

           smpte240m
               SMPTE-240M

           bt2020
               BT.2020

       For example to convert from BT.601 to SMPTE-240M, use the command:

               colormatrix=bt601:smpte240m

   colorspace
       Convert colorspace, transfer characteristics or color primaries.  Input video needs to have an even size.

       The filter accepts the following options:

       all Specify all color properties at once.

           The accepted values are:

           bt470m
               BT.470M

           bt470bg
               BT.470BG

           bt601-6-525
               BT.601-6 525

           bt601-6-625
               BT.601-6 625

           bt709
               BT.709

           smpte170m
               SMPTE-170M

           smpte240m
               SMPTE-240M

           bt2020
               BT.2020

       space
           Specify output colorspace.

           The accepted values are:

           bt709
               BT.709

           fcc FCC

           bt470bg
               BT.470BG or BT.601-6 625

           smpte170m
               SMPTE-170M or BT.601-6 525

           smpte240m
               SMPTE-240M

           ycgco
               YCgCo

           bt2020ncl
               BT.2020 with non-constant luminance

       trc Specify output transfer characteristics.

           The accepted values are:

           bt709
               BT.709

           bt470m
               BT.470M

           bt470bg
               BT.470BG

           gamma22
               Constant gamma of 2.2

           gamma28
               Constant gamma of 2.8

           smpte170m
               SMPTE-170M, BT.601-6 625 or BT.601-6 525

           smpte240m
               SMPTE-240M

           srgb
               SRGB

           iec61966-2-1
               iec61966-2-1

           iec61966-2-4
               iec61966-2-4

           xvycc
               xvycc

           bt2020-10
               BT.2020 for 10-bits content

           bt2020-12
               BT.2020 for 12-bits content

       primaries
           Specify output color primaries.

           The accepted values are:

           bt709
               BT.709

           bt470m
               BT.470M

           bt470bg
               BT.470BG or BT.601-6 625

           smpte170m
               SMPTE-170M or BT.601-6 525

           smpte240m
               SMPTE-240M

           film
               film

           smpte431
               SMPTE-431

           smpte432
               SMPTE-432

           bt2020
               BT.2020

           jedec-p22
               JEDEC P22 phosphors

       range
           Specify output color range.

           The accepted values are:

           tv  TV (restricted) range

           mpeg
               MPEG (restricted) range

           pc  PC (full) range

           jpeg
               JPEG (full) range

       format
           Specify output color format.

           The accepted values are:

           yuv420p
               YUV 4:2:0 planar 8-bits

           yuv420p10
               YUV 4:2:0 planar 10-bits

           yuv420p12
               YUV 4:2:0 planar 12-bits

           yuv422p
               YUV 4:2:2 planar 8-bits

           yuv422p10
               YUV 4:2:2 planar 10-bits

           yuv422p12
               YUV 4:2:2 planar 12-bits

           yuv444p
               YUV 4:4:4 planar 8-bits

           yuv444p10
               YUV 4:4:4 planar 10-bits

           yuv444p12
               YUV 4:4:4 planar 12-bits

       fast
           Do a fast conversion, which skips gamma/primary correction. This will take significantly less CPU, but will be
           mathematically incorrect. To get output compatible with that produced by the colormatrix filter, use fast=1.

       dither
           Specify dithering mode.

           The accepted values are:

           none
               No dithering

           fsb Floyd-Steinberg dithering

       wpadapt
           Whitepoint adaptation mode.

           The accepted values are:

           bradford
               Bradford whitepoint adaptation

           vonkries
               von Kries whitepoint adaptation

           identity
               identity whitepoint adaptation (i.e. no whitepoint adaptation)

       iall
           Override all input properties at once. Same accepted values as all.

       ispace
           Override input colorspace. Same accepted values as space.

       iprimaries
           Override input color primaries. Same accepted values as primaries.

       itrc
           Override input transfer characteristics. Same accepted values as trc.

       irange
           Override input color range. Same accepted values as range.

       The filter converts the transfer characteristics, color space and color primaries to the specified user values. The output
       value, if not specified, is set to a default value based on the "all" property. If that property is also not specified, the
       filter will log an error. The output color range and format default to the same value as the input color range and format.
       The input transfer characteristics, color space, color primaries and color range should be set on the input data. If any of
       these are missing, the filter will log an error and no conversion will take place.

       For example to convert the input to SMPTE-240M, use the command:

               colorspace=smpte240m

   colortemperature
       Adjust color temperature in video to simulate variations in ambient color temperature.

       The filter accepts the following options:

       temperature
           Set the temperature in Kelvin. Allowed range is from 1000 to 40000.  Default value is 6500 K.

       mix Set mixing with filtered output. Allowed range is from 0 to 1.  Default value is 1.

       pl  Set the amount of preserving lightness. Allowed range is from 0 to 1.  Default value is 0.

       Commands

       This filter supports same commands as options.

   convolution
       Apply convolution of 3x3, 5x5, 7x7 or horizontal/vertical up to 49 elements.

       The filter accepts the following options:

       0m
       1m
       2m
       3m  Set matrix for each plane.  Matrix is sequence of 9, 25 or 49 signed integers in square mode, and from 1 to 49 odd
           number of signed integers in row mode.

       0rdiv
       1rdiv
       2rdiv
       3rdiv
           Set multiplier for calculated value for each plane.  If unset or 0, it will be sum of all matrix elements.

       0bias
       1bias
       2bias
       3bias
           Set bias for each plane. This value is added to the result of the multiplication.  Useful for making the overall image
           brighter or darker. Default is 0.0.

       0mode
       1mode
       2mode
       3mode
           Set matrix mode for each plane. Can be square, row or column.  Default is square.

       Commands

       This filter supports the all above options as commands.

       Examples

       •   Apply sharpen:

                   convolution="0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0"

       •   Apply blur:

                   convolution="1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1/9:1/9:1/9:1/9"

       •   Apply edge enhance:

                   convolution="0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:5:1:1:1:0:128:128:128"

       •   Apply edge detect:

                   convolution="0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:5:5:5:1:0:128:128:128"

       •   Apply laplacian edge detector which includes diagonals:

                   convolution="1 1 1 1 -8 1 1 1 1:1 1 1 1 -8 1 1 1 1:1 1 1 1 -8 1 1 1 1:1 1 1 1 -8 1 1 1 1:5:5:5:1:0:128:128:0"

       •   Apply emboss:

                   convolution="-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2"

   convolve
       Apply 2D convolution of video stream in frequency domain using second stream as impulse.

       The filter accepts the following options:

       planes
           Set which planes to process.

       impulse
           Set which impulse video frames will be processed, can be first or all. Default is all.

       The "convolve" filter also supports the framesync options.

   copy
       Copy the input video source unchanged to the output. This is mainly useful for testing purposes.

   coreimage
       Video filtering on GPU using Apple's CoreImage API on OSX.

       Hardware acceleration is based on an OpenGL context. Usually, this means it is processed by video hardware. However,
       software-based OpenGL implementations exist which means there is no guarantee for hardware processing. It depends on the
       respective OSX.

       There are many filters and image generators provided by Apple that come with a large variety of options. The filter has to
       be referenced by its name along with its options.

       The coreimage filter accepts the following options:

       list_filters
           List all available filters and generators along with all their respective options as well as possible minimum and
           maximum values along with the default values.

                   list_filters=true

       filter
           Specify all filters by their respective name and options.  Use list_filters to determine all valid filter names and
           options.  Numerical options are specified by a float value and are automatically clamped to their respective value
           range.  Vector and color options have to be specified by a list of space separated float values. Character escaping has
           to be done.  A special option name "default" is available to use default options for a filter.

           It is required to specify either "default" or at least one of the filter options.  All omitted options are used with
           their default values.  The syntax of the filter string is as follows:

                   filter=<NAME>@<OPTION>=<VALUE>[@<OPTION>=<VALUE>][@...][#<NAME>@<OPTION>=<VALUE>[@<OPTION>=<VALUE>][@...]][#...]

       output_rect
           Specify a rectangle where the output of the filter chain is copied into the input image. It is given by a list of space
           separated float values:

                   output_rect=x\ y\ width\ height

           If not given, the output rectangle equals the dimensions of the input image.  The output rectangle is automatically
           cropped at the borders of the input image. Negative values are valid for each component.

                   output_rect=25\ 25\ 100\ 100

       Several filters can be chained for successive processing without GPU-HOST transfers allowing for fast processing of complex
       filter chains.  Currently, only filters with zero (generators) or exactly one (filters) input image and one output image are
       supported. Also, transition filters are not yet usable as intended.

       Some filters generate output images with additional padding depending on the respective filter kernel. The padding is
       automatically removed to ensure the filter output has the same size as the input image.

       For image generators, the size of the output image is determined by the previous output image of the filter chain or the
       input image of the whole filterchain, respectively. The generators do not use the pixel information of this image to
       generate their output. However, the generated output is blended onto this image, resulting in partial or complete coverage
       of the output image.

       The coreimagesrc video source can be used for generating input images which are directly fed into the filter chain. By using
       it, providing input images by another video source or an input video is not required.

       Examples

       •   List all filters available:

                   coreimage=list_filters=true

       •   Use the CIBoxBlur filter with default options to blur an image:

                   coreimage=filter=CIBoxBlur@default

       •   Use a filter chain with CISepiaTone at default values and CIVignetteEffect with its center at 100x100 and a radius of 50
           pixels:

                   coreimage=filter=CIBoxBlur@default#CIVignetteEffect@inputCenter=100\ 100@inputRadius=50

       •   Use nullsrc and CIQRCodeGenerator to create a QR code for the FFmpeg homepage, given as complete and escaped command-
           line for Apple's standard bash shell:

                   ffmpeg -f lavfi -i nullsrc=s=100x100,coreimage=filter=CIQRCodeGenerator@inputMessage=https\\\\\://FFmpeg.org/@inputCorrectionLevel=H -frames:v 1 QRCode.png

   cover_rect
       Cover a rectangular object

       It accepts the following options:

       cover
           Filepath of the optional cover image, needs to be in yuv420.

       mode
           Set covering mode.

           It accepts the following values:

           cover
               cover it by the supplied image

           blur
               cover it by interpolating the surrounding pixels

           Default value is blur.

       Examples

       •   Cover a rectangular object by the supplied image of a given video using ffmpeg:

                   ffmpeg -i file.ts -vf find_rect=newref.pgm,cover_rect=cover.jpg:mode=cover new.mkv

   crop
       Crop the input video to given dimensions.

       It accepts the following parameters:

       w, out_w
           The width of the output video. It defaults to "iw".  This expression is evaluated only once during the filter
           configuration, or when the w or out_w command is sent.

       h, out_h
           The height of the output video. It defaults to "ih".  This expression is evaluated only once during the filter
           configuration, or when the h or out_h command is sent.

       x   The horizontal position, in the input video, of the left edge of the output video. It defaults to "(in_w-out_w)/2".
           This expression is evaluated per-frame.

       y   The vertical position, in the input video, of the top edge of the output video.  It defaults to "(in_h-out_h)/2".  This
           expression is evaluated per-frame.

       keep_aspect
           If set to 1 will force the output display aspect ratio to be the same of the input, by changing the output sample aspect
           ratio. It defaults to 0.

       exact
           Enable exact cropping. If enabled, subsampled videos will be cropped at exact width/height/x/y as specified and will not
           be rounded to nearest smaller value.  It defaults to 0.

       The out_w, out_h, x, y parameters are expressions containing the following constants:

       x
       y   The computed values for x and y. They are evaluated for each new frame.

       in_w
       in_h
           The input width and height.

       iw
       ih  These are the same as in_w and in_h.

       out_w
       out_h
           The output (cropped) width and height.

       ow
       oh  These are the same as out_w and out_h.

       a   same as iw / ih

       sar input sample aspect ratio

       dar input display aspect ratio, it is the same as (iw / ih) * sar

       hsub
       vsub
           horizontal and vertical chroma subsample values. For example for the pixel format "yuv422p" hsub is 2 and vsub is 1.

       n   The number of the input frame, starting from 0.

       pos the position in the file of the input frame, NAN if unknown

       t   The timestamp expressed in seconds. It's NAN if the input timestamp is unknown.

       The expression for out_w may depend on the value of out_h, and the expression for out_h may depend on out_w, but they cannot
       depend on x and y, as x and y are evaluated after out_w and out_h.

       The x and y parameters specify the expressions for the position of the top-left corner of the output (non-cropped) area.
       They are evaluated for each frame. If the evaluated value is not valid, it is approximated to the nearest valid value.

       The expression for x may depend on y, and the expression for y may depend on x.

       Examples

       •   Crop area with size 100x100 at position (12,34).

                   crop=100:100:12:34

           Using named options, the example above becomes:

                   crop=w=100:h=100:x=12:y=34

       •   Crop the central input area with size 100x100:

                   crop=100:100

       •   Crop the central input area with size 2/3 of the input video:

                   crop=2/3*in_w:2/3*in_h

       •   Crop the input video central square:

                   crop=out_w=in_h
                   crop=in_h

       •   Delimit the rectangle with the top-left corner placed at position 100:100 and the right-bottom corner corresponding to
           the right-bottom corner of the input image.

                   crop=in_w-100:in_h-100:100:100

       •   Crop 10 pixels from the left and right borders, and 20 pixels from the top and bottom borders

                   crop=in_w-2*10:in_h-2*20

       •   Keep only the bottom right quarter of the input image:

                   crop=in_w/2:in_h/2:in_w/2:in_h/2

       •   Crop height for getting Greek harmony:

                   crop=in_w:1/PHI*in_w

       •   Apply trembling effect:

                   crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(n/10):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(n/7)

       •   Apply erratic camera effect depending on timestamp:

                   crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(t*10):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(t*13)"

       •   Set x depending on the value of y:

                   crop=in_w/2:in_h/2:y:10+10*sin(n/10)

       Commands

       This filter supports the following commands:

       w, out_w
       h, out_h
       x
       y   Set width/height of the output video and the horizontal/vertical position in the input video.  The command accepts the
           same syntax of the corresponding option.

           If the specified expression is not valid, it is kept at its current value.

   cropdetect
       Auto-detect the crop size.

       It calculates the necessary cropping parameters and prints the recommended parameters via the logging system. The detected
       dimensions correspond to the non-black area of the input video.

       It accepts the following parameters:

       limit
           Set higher black value threshold, which can be optionally specified from nothing (0) to everything (255 for 8-bit based
           formats). An intensity value greater to the set value is considered non-black. It defaults to 24.  You can also specify
           a value between 0.0 and 1.0 which will be scaled depending on the bitdepth of the pixel format.

       round
           The value which the width/height should be divisible by. It defaults to 16. The offset is automatically adjusted to
           center the video. Use 2 to get only even dimensions (needed for 4:2:2 video). 16 is best when encoding to most video
           codecs.

       skip
           Set the number of initial frames for which evaluation is skipped.  Default is 2. Range is 0 to INT_MAX.

       reset_count, reset
           Set the counter that determines after how many frames cropdetect will reset the previously detected largest video area
           and start over to detect the current optimal crop area. Default value is 0.

           This can be useful when channel logos distort the video area. 0 indicates 'never reset', and returns the largest area
           encountered during playback.

   cue
       Delay video filtering until a given wallclock timestamp. The filter first passes on preroll amount of frames, then it
       buffers at most buffer amount of frames and waits for the cue. After reaching the cue it forwards the buffered frames and
       also any subsequent frames coming in its input.

       The filter can be used synchronize the output of multiple ffmpeg processes for realtime output devices like decklink. By
       putting the delay in the filtering chain and pre-buffering frames the process can pass on data to output almost immediately
       after the target wallclock timestamp is reached.

       Perfect frame accuracy cannot be guaranteed, but the result is good enough for some use cases.

       cue The cue timestamp expressed in a UNIX timestamp in microseconds. Default is 0.

       preroll
           The duration of content to pass on as preroll expressed in seconds. Default is 0.

       buffer
           The maximum duration of content to buffer before waiting for the cue expressed in seconds. Default is 0.

   curves
       Apply color adjustments using curves.

       This filter is similar to the Adobe Photoshop and GIMP curves tools. Each component (red, green and blue) has its values
       defined by N key points tied from each other using a smooth curve. The x-axis represents the pixel values from the input
       frame, and the y-axis the new pixel values to be set for the output frame.

       By default, a component curve is defined by the two points (0;0) and (1;1). This creates a straight line where each original
       pixel value is "adjusted" to its own value, which means no change to the image.

       The filter allows you to redefine these two points and add some more. A new curve (using a natural cubic spline
       interpolation) will be define to pass smoothly through all these new coordinates. The new defined points needs to be
       strictly increasing over the x-axis, and their x and y values must be in the [0;1] interval.  If the computed curves
       happened to go outside the vector spaces, the values will be clipped accordingly.

       The filter accepts the following options:

       preset
           Select one of the available color presets. This option can be used in addition to the r, g, b parameters; in this case,
           the later options takes priority on the preset values.  Available presets are:

           none
           color_negative
           cross_process
           darker
           increase_contrast
           lighter
           linear_contrast
           medium_contrast
           negative
           strong_contrast
           vintage

           Default is "none".

       master, m
           Set the master key points. These points will define a second pass mapping. It is sometimes called a "luminance" or
           "value" mapping. It can be used with r, g, b or all since it acts like a post-processing LUT.

       red, r
           Set the key points for the red component.

       green, g
           Set the key points for the green component.

       blue, b
           Set the key points for the blue component.

       all Set the key points for all components (not including master).  Can be used in addition to the other key points component
           options. In this case, the unset component(s) will fallback on this all setting.

       psfile
           Specify a Photoshop curves file (".acv") to import the settings from.

       plot
           Save Gnuplot script of the curves in specified file.

       To avoid some filtergraph syntax conflicts, each key points list need to be defined using the following syntax: "x0/y0 x1/y1
       x2/y2 ...".

       Commands

       This filter supports same commands as options.

       Examples

       •   Increase slightly the middle level of blue:

                   curves=blue='0/0 0.5/0.58 1/1'

       •   Vintage effect:

                   curves=r='0/0.11 .42/.51 1/0.95':g='0/0 0.50/0.48 1/1':b='0/0.22 .49/.44 1/0.8'

           Here we obtain the following coordinates for each components:

           red "(0;0.11) (0.42;0.51) (1;0.95)"

           green
               "(0;0) (0.50;0.48) (1;1)"

           blue
               "(0;0.22) (0.49;0.44) (1;0.80)"

       •   The previous example can also be achieved with the associated built-in preset:

                   curves=preset=vintage

       •   Or simply:

                   curves=vintage

       •   Use a Photoshop preset and redefine the points of the green component:

                   curves=psfile='MyCurvesPresets/purple.acv':green='0/0 0.45/0.53 1/1'

       •   Check out the curves of the "cross_process" profile using ffmpeg and gnuplot:

                   ffmpeg -f lavfi -i color -vf curves=cross_process:plot=/tmp/curves.plt -frames:v 1 -f null -
                   gnuplot -p /tmp/curves.plt

   datascope
       Video data analysis filter.

       This filter shows hexadecimal pixel values of part of video.

       The filter accepts the following options:

       size, s
           Set output video size.

       x   Set x offset from where to pick pixels.

       y   Set y offset from where to pick pixels.

       mode
           Set scope mode, can be one of the following:

           mono
               Draw hexadecimal pixel values with white color on black background.

           color
               Draw hexadecimal pixel values with input video pixel color on black background.

           color2
               Draw hexadecimal pixel values on color background picked from input video, the text color is picked in such way so
               its always visible.

       axis
           Draw rows and columns numbers on left and top of video.

       opacity
           Set background opacity.

       format
           Set display number format. Can be "hex", or "dec". Default is "hex".

       components
           Set pixel components to display. By default all pixel components are displayed.

       Commands

       This filter supports same commands as options excluding "size" option.

   dblur
       Apply Directional blur filter.

       The filter accepts the following options:

       angle
           Set angle of directional blur. Default is 45.

       radius
           Set radius of directional blur. Default is 5.

       planes
           Set which planes to filter. By default all planes are filtered.

       Commands

       This filter supports same commands as options.  The command accepts the same syntax of the corresponding option.

       If the specified expression is not valid, it is kept at its current value.

   dctdnoiz
       Denoise frames using 2D DCT (frequency domain filtering).

       This filter is not designed for real time.

       The filter accepts the following options:

       sigma, s
           Set the noise sigma constant.

           This sigma defines a hard threshold of "3 * sigma"; every DCT coefficient (absolute value) below this threshold with be
           dropped.

           If you need a more advanced filtering, see expr.

           Default is 0.

       overlap
           Set number overlapping pixels for each block. Since the filter can be slow, you may want to reduce this value, at the
           cost of a less effective filter and the risk of various artefacts.

           If the overlapping value doesn't permit processing the whole input width or height, a warning will be displayed and
           according borders won't be denoised.

           Default value is blocksize-1, which is the best possible setting.

       expr, e
           Set the coefficient factor expression.

           For each coefficient of a DCT block, this expression will be evaluated as a multiplier value for the coefficient.

           If this is option is set, the sigma option will be ignored.

           The absolute value of the coefficient can be accessed through the c variable.

       n   Set the blocksize using the number of bits. "1<<n" defines the blocksize, which is the width and height of the processed
           blocks.

           The default value is 3 (8x8) and can be raised to 4 for a blocksize of 16x16. Note that changing this setting has huge
           consequences on the speed processing. Also, a larger block size does not necessarily means a better de-noising.

       Examples

       Apply a denoise with a sigma of 4.5:

               dctdnoiz=4.5

       The same operation can be achieved using the expression system:

               dctdnoiz=e='gte(c, 4.5*3)'

       Violent denoise using a block size of "16x16":

               dctdnoiz=15:n=4

   deband
       Remove banding artifacts from input video.  It works by replacing banded pixels with average value of referenced pixels.

       The filter accepts the following options:

       1thr
       2thr
       3thr
       4thr
           Set banding detection threshold for each plane. Default is 0.02.  Valid range is 0.00003 to 0.5.  If difference between
           current pixel and reference pixel is less than threshold, it will be considered as banded.

       range, r
           Banding detection range in pixels. Default is 16. If positive, random number in range 0 to set value will be used. If
           negative, exact absolute value will be used.  The range defines square of four pixels around current pixel.

       direction, d
           Set direction in radians from which four pixel will be compared. If positive, random direction from 0 to set direction
           will be picked. If negative, exact of absolute value will be picked. For example direction 0, -PI or -2*PI radians will
           pick only pixels on same row and -PI/2 will pick only pixels on same column.

       blur, b
           If enabled, current pixel is compared with average value of all four surrounding pixels. The default is enabled. If
           disabled current pixel is compared with all four surrounding pixels. The pixel is considered banded if only all four
           differences with surrounding pixels are less than threshold.

       coupling, c
           If enabled, current pixel is changed if and only if all pixel components are banded, e.g. banding detection threshold is
           triggered for all color components.  The default is disabled.

       Commands

       This filter supports the all above options as commands.

   deblock
       Remove blocking artifacts from input video.

       The filter accepts the following options:

       filter
           Set filter type, can be weak or strong. Default is strong.  This controls what kind of deblocking is applied.

       block
           Set size of block, allowed range is from 4 to 512. Default is 8.

       alpha
       beta
       gamma
       delta
           Set blocking detection thresholds. Allowed range is 0 to 1.  Defaults are: 0.098 for alpha and 0.05 for the rest.  Using
           higher threshold gives more deblocking strength.  Setting alpha controls threshold detection at exact edge of block.
           Remaining options controls threshold detection near the edge. Each one for below/above or left/right. Setting any of
           those to 0 disables deblocking.

       planes
           Set planes to filter. Default is to filter all available planes.

       Examples

       •   Deblock using weak filter and block size of 4 pixels.

                   deblock=filter=weak:block=4

       •   Deblock using strong filter, block size of 4 pixels and custom thresholds for deblocking more edges.

                   deblock=filter=strong:block=4:alpha=0.12:beta=0.07:gamma=0.06:delta=0.05

       •   Similar as above, but filter only first plane.

                   deblock=filter=strong:block=4:alpha=0.12:beta=0.07:gamma=0.06:delta=0.05:planes=1

       •   Similar as above, but filter only second and third plane.

                   deblock=filter=strong:block=4:alpha=0.12:beta=0.07:gamma=0.06:delta=0.05:planes=6

       Commands

       This filter supports the all above options as commands.

   decimate
       Drop duplicated frames at regular intervals.

       The filter accepts the following options:

       cycle
           Set the number of frames from which one will be dropped. Setting this to N means one frame in every batch of N frames
           will be dropped.  Default is 5.

       dupthresh
           Set the threshold for duplicate detection. If the difference metric for a frame is less than or equal to this value,
           then it is declared as duplicate. Default is 1.1

       scthresh
           Set scene change threshold. Default is 15.

       blockx
       blocky
           Set the size of the x and y-axis blocks used during metric calculations.  Larger blocks give better noise suppression,
           but also give worse detection of small movements. Must be a power of two. Default is 32.

       ppsrc
           Mark main input as a pre-processed input and activate clean source input stream. This allows the input to be pre-
           processed with various filters to help the metrics calculation while keeping the frame selection lossless. When set to
           1, the first stream is for the pre-processed input, and the second stream is the clean source from where the kept frames
           are chosen. Default is 0.

       chroma
           Set whether or not chroma is considered in the metric calculations. Default is 1.

   deconvolve
       Apply 2D deconvolution of video stream in frequency domain using second stream as impulse.

       The filter accepts the following options:

       planes
           Set which planes to process.

       impulse
           Set which impulse video frames will be processed, can be first or all. Default is all.

       noise
           Set noise when doing divisions. Default is 0.0000001. Useful when width and height are not same and not power of 2 or if
           stream prior to convolving had noise.

       The "deconvolve" filter also supports the framesync options.

   dedot
       Reduce cross-luminance (dot-crawl) and cross-color (rainbows) from video.

       It accepts the following options:

       m   Set mode of operation. Can be combination of dotcrawl for cross-luminance reduction and/or rainbows for cross-color
           reduction.

       lt  Set spatial luma threshold. Lower values increases reduction of cross-luminance.

       tl  Set tolerance for temporal luma. Higher values increases reduction of cross-luminance.

       tc  Set tolerance for chroma temporal variation. Higher values increases reduction of cross-color.

       ct  Set temporal chroma threshold. Lower values increases reduction of cross-color.

   deflate
       Apply deflate effect to the video.

       This filter replaces the pixel by the local(3x3) average by taking into account only values lower than the pixel.

       It accepts the following options:

       threshold0
       threshold1
       threshold2
       threshold3
           Limit the maximum change for each plane, default is 65535.  If 0, plane will remain unchanged.

       Commands

       This filter supports the all above options as commands.

   deflicker
       Remove temporal frame luminance variations.

       It accepts the following options:

       size, s
           Set moving-average filter size in frames. Default is 5. Allowed range is 2 - 129.

       mode, m
           Set averaging mode to smooth temporal luminance variations.

           Available values are:

           am  Arithmetic mean

           gm  Geometric mean

           hm  Harmonic mean

           qm  Quadratic mean

           cm  Cubic mean

           pm  Power mean

           median
               Median

       bypass
           Do not actually modify frame. Useful when one only wants metadata.

   dejudder
       Remove judder produced by partially interlaced telecined content.

       Judder can be introduced, for instance, by pullup filter. If the original source was partially telecined content then the
       output of "pullup,dejudder" will have a variable frame rate. May change the recorded frame rate of the container. Aside from
       that change, this filter will not affect constant frame rate video.

       The option available in this filter is:

       cycle
           Specify the length of the window over which the judder repeats.

           Accepts any integer greater than 1. Useful values are:

           4   If the original was telecined from 24 to 30 fps (Film to NTSC).

           5   If the original was telecined from 25 to 30 fps (PAL to NTSC).

           20  If a mixture of the two.

           The default is 4.

   delogo
       Suppress a TV station logo by a simple interpolation of the surrounding pixels. Just set a rectangle covering the logo and
       watch it disappear (and sometimes something even uglier appear - your mileage may vary).

       It accepts the following parameters:

       x
       y   Specify the top left corner coordinates of the logo. They must be specified.

       w
       h   Specify the width and height of the logo to clear. They must be specified.

       show
           When set to 1, a green rectangle is drawn on the screen to simplify finding the right x, y, w, and h parameters.  The
           default value is 0.

           The rectangle is drawn on the outermost pixels which will be (partly) replaced with interpolated values. The values of
           the next pixels immediately outside this rectangle in each direction will be used to compute the interpolated pixel
           values inside the rectangle.

       Examples

       •   Set a rectangle covering the area with top left corner coordinates 0,0 and size 100x77:

                   delogo=x=0:y=0:w=100:h=77

   derain
       Remove the rain in the input image/video by applying the derain methods based on convolutional neural networks. Supported
       models:

       •   Recurrent Squeeze-and-Excitation Context Aggregation Net (RESCAN).  See
           <http://openaccess.thecvf.com/content_ECCV_2018/papers/Xia_Li_Recurrent_Squeeze-and-Excitation_Context_ECCV_2018_paper.pdf>.

       Training as well as model generation scripts are provided in the repository at
       <https://github.com/XueweiMeng/derain_filter.git>.

       Native model files (.model) can be generated from TensorFlow model files (.pb) by using tools/python/convert.py

       The filter accepts the following options:

       filter_type
           Specify which filter to use. This option accepts the following values:

           derain
               Derain filter. To conduct derain filter, you need to use a derain model.

           dehaze
               Dehaze filter. To conduct dehaze filter, you need to use a dehaze model.

           Default value is derain.

       dnn_backend
           Specify which DNN backend to use for model loading and execution. This option accepts the following values:

           native
               Native implementation of DNN loading and execution.

           tensorflow
               TensorFlow backend. To enable this backend you need to install the TensorFlow for C library (see
               <https://www.tensorflow.org/install/lang_c>) and configure FFmpeg with "--enable-libtensorflow"

           Default value is native.

       model
           Set path to model file specifying network architecture and its parameters.  Note that different backends use different
           file formats. TensorFlow and native backend can load files for only its format.

       To get full functionality (such as async execution), please use the dnn_processing filter.

   deshake
       Attempt to fix small changes in horizontal and/or vertical shift. This filter helps remove camera shake from hand-holding a
       camera, bumping a tripod, moving on a vehicle, etc.

       The filter accepts the following options:

       x
       y
       w
       h   Specify a rectangular area where to limit the search for motion vectors.  If desired the search for motion vectors can
           be limited to a rectangular area of the frame defined by its top left corner, width and height. These parameters have
           the same meaning as the drawbox filter which can be used to visualise the position of the bounding box.

           This is useful when simultaneous movement of subjects within the frame might be confused for camera motion by the motion
           vector search.

           If any or all of x, y, w and h are set to -1 then the full frame is used. This allows later options to be set without
           specifying the bounding box for the motion vector search.

           Default - search the whole frame.

       rx
       ry  Specify the maximum extent of movement in x and y directions in the range 0-64 pixels. Default 16.

       edge
           Specify how to generate pixels to fill blanks at the edge of the frame. Available values are:

           blank, 0
               Fill zeroes at blank locations

           original, 1
               Original image at blank locations

           clamp, 2
               Extruded edge value at blank locations

           mirror, 3
               Mirrored edge at blank locations

           Default value is mirror.

       blocksize
           Specify the blocksize to use for motion search. Range 4-128 pixels, default 8.

       contrast
           Specify the contrast threshold for blocks. Only blocks with more than the specified contrast (difference between darkest
           and lightest pixels) will be considered. Range 1-255, default 125.

       search
           Specify the search strategy. Available values are:

           exhaustive, 0
               Set exhaustive search

           less, 1
               Set less exhaustive search.

           Default value is exhaustive.

       filename
           If set then a detailed log of the motion search is written to the specified file.

   despill
       Remove unwanted contamination of foreground colors, caused by reflected color of greenscreen or bluescreen.

       This filter accepts the following options:

       type
           Set what type of despill to use.

       mix Set how spillmap will be generated.

       expand
           Set how much to get rid of still remaining spill.

       red Controls amount of red in spill area.

       green
           Controls amount of green in spill area.  Should be -1 for greenscreen.

       blue
           Controls amount of blue in spill area.  Should be -1 for bluescreen.

       brightness
           Controls brightness of spill area, preserving colors.

       alpha
           Modify alpha from generated spillmap.

       Commands

       This filter supports the all above options as commands.

   detelecine
       Apply an exact inverse of the telecine operation. It requires a predefined pattern specified using the pattern option which
       must be the same as that passed to the telecine filter.

       This filter accepts the following options:

       first_field
           top, t
               top field first

           bottom, b
               bottom field first The default value is "top".

       pattern
           A string of numbers representing the pulldown pattern you wish to apply.  The default value is 23.

       start_frame
           A number representing position of the first frame with respect to the telecine pattern. This is to be used if the stream
           is cut. The default value is 0.

   dilation
       Apply dilation effect to the video.

       This filter replaces the pixel by the local(3x3) maximum.

       It accepts the following options:

       threshold0
       threshold1
       threshold2
       threshold3
           Limit the maximum change for each plane, default is 65535.  If 0, plane will remain unchanged.

       coordinates
           Flag which specifies the pixel to refer to. Default is 255 i.e. all eight pixels are used.

           Flags to local 3x3 coordinates maps like this:

               1 2 3
               4   5
               6 7 8

       Commands

       This filter supports the all above options as commands.

   displace
       Displace pixels as indicated by second and third input stream.

       It takes three input streams and outputs one stream, the first input is the source, and second and third input are
       displacement maps.

       The second input specifies how much to displace pixels along the x-axis, while the third input specifies how much to
       displace pixels along the y-axis.  If one of displacement map streams terminates, last frame from that displacement map will
       be used.

       Note that once generated, displacements maps can be reused over and over again.

       A description of the accepted options follows.

       edge
           Set displace behavior for pixels that are out of range.

           Available values are:

           blank
               Missing pixels are replaced by black pixels.

           smear
               Adjacent pixels will spread out to replace missing pixels.

           wrap
               Out of range pixels are wrapped so they point to pixels of other side.

           mirror
               Out of range pixels will be replaced with mirrored pixels.

           Default is smear.

       Examples

       •   Add ripple effect to rgb input of video size hd720:

                   ffmpeg -i INPUT -f lavfi -i nullsrc=s=hd720,lutrgb=128:128:128 -f lavfi -i nullsrc=s=hd720,geq='r=128+30*sin(2*PI*X/400+T):g=128+30*sin(2*PI*X/400+T):b=128+30*sin(2*PI*X/400+T)' -lavfi '[0][1][2]displace' OUTPUT

       •   Add wave effect to rgb input of video size hd720:

                   ffmpeg -i INPUT -f lavfi -i nullsrc=hd720,geq='r=128+80*(sin(sqrt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2))/220*2*PI+T)):g=128+80*(sin(sqrt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2))/220*2*PI+T)):b=128+80*(sin(sqrt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2))/220*2*PI+T))' -lavfi '[1]split[x][y],[0][x][y]displace' OUTPUT

   dnn_classify
       Do classification with deep neural networks based on bounding boxes.

       The filter accepts the following options:

       dnn_backend
           Specify which DNN backend to use for model loading and execution. This option accepts only openvino now, tensorflow
           backends will be added.

       model
           Set path to model file specifying network architecture and its parameters.  Note that different backends use different
           file formats.

       input
           Set the input name of the dnn network.

       output
           Set the output name of the dnn network.

       confidence
           Set the confidence threshold (default: 0.5).

       labels
           Set path to label file specifying the mapping between label id and name.  Each label name is written in one line,
           tailing spaces and empty lines are skipped.  The first line is the name of label id 0, and the second line is the name
           of label id 1, etc.  The label id is considered as name if the label file is not provided.

       backend_configs
           Set the configs to be passed into backend

           For tensorflow backend, you can set its configs with sess_config options, please use tools/python/tf_sess_config.py to
           get the configs for your system.

   dnn_detect
       Do object detection with deep neural networks.

       The filter accepts the following options:

       dnn_backend
           Specify which DNN backend to use for model loading and execution. This option accepts only openvino now, tensorflow
           backends will be added.

       model
           Set path to model file specifying network architecture and its parameters.  Note that different backends use different
           file formats.

       input
           Set the input name of the dnn network.

       output
           Set the output name of the dnn network.

       confidence
           Set the confidence threshold (default: 0.5).

       labels
           Set path to label file specifying the mapping between label id and name.  Each label name is written in one line,
           tailing spaces and empty lines are skipped.  The first line is the name of label id 0 (usually it is 'background'), and
           the second line is the name of label id 1, etc.  The label id is considered as name if the label file is not provided.

       backend_configs
           Set the configs to be passed into backend. To use async execution, set async (default: set).  Roll back to sync
           execution if the backend does not support async.

   dnn_processing
       Do image processing with deep neural networks. It works together with another filter which converts the pixel format of the
       Frame to what the dnn network requires.

       The filter accepts the following options:

       dnn_backend
           Specify which DNN backend to use for model loading and execution. This option accepts the following values:

           native
               Native implementation of DNN loading and execution.

           tensorflow
               TensorFlow backend. To enable this backend you need to install the TensorFlow for C library (see
               <https://www.tensorflow.org/install/lang_c>) and configure FFmpeg with "--enable-libtensorflow"

           openvino
               OpenVINO backend. To enable this backend you need to build and install the OpenVINO for C library (see
               <https://github.com/openvinotoolkit/openvino/blob/master/build-instruction.md>) and configure FFmpeg with
               "--enable-libopenvino" (--extra-cflags=-I... --extra-ldflags=-L... might be needed if the header files and libraries
               are not installed into system path)

           Default value is native.

       model
           Set path to model file specifying network architecture and its parameters.  Note that different backends use different
           file formats. TensorFlow, OpenVINO and native backend can load files for only its format.

           Native model file (.model) can be generated from TensorFlow model file (.pb) by using tools/python/convert.py

       input
           Set the input name of the dnn network.

       output
           Set the output name of the dnn network.

       backend_configs
           Set the configs to be passed into backend. To use async execution, set async (default: set).  Roll back to sync
           execution if the backend does not support async.

           For tensorflow backend, you can set its configs with sess_config options, please use tools/python/tf_sess_config.py to
           get the configs of TensorFlow backend for your system.

       Examples

       •   Remove rain in rgb24 frame with can.pb (see derain filter):

                   ./ffmpeg -i rain.jpg -vf format=rgb24,dnn_processing=dnn_backend=tensorflow:model=can.pb:input=x:output=y derain.jpg

       •   Halve the pixel value of the frame with format gray32f:

                   ffmpeg -i input.jpg -vf format=grayf32,dnn_processing=model=halve_gray_float.model:input=dnn_in:output=dnn_out:dnn_backend=native -y out.native.png

       •   Handle the Y channel with srcnn.pb (see sr filter) for frame with yuv420p (planar YUV formats supported):

                   ./ffmpeg -i 480p.jpg -vf format=yuv420p,scale=w=iw*2:h=ih*2,dnn_processing=dnn_backend=tensorflow:model=srcnn.pb:input=x:output=y -y srcnn.jpg

       •   Handle the Y channel with espcn.pb (see sr filter), which changes frame size, for format yuv420p (planar YUV formats
           supported), please use tools/python/tf_sess_config.py to get the configs of TensorFlow backend for your system.

                   ./ffmpeg -i 480p.jpg -vf format=yuv420p,dnn_processing=dnn_backend=tensorflow:model=espcn.pb:input=x:output=y:backend_configs=sess_config=0x10022805320e09cdccccccccccec3f20012a01303801 -y tmp.espcn.jpg

   drawbox
       Draw a colored box on the input image.

       It accepts the following parameters:

       x
       y   The expressions which specify the top left corner coordinates of the box. It defaults to 0.

       width, w
       height, h
           The expressions which specify the width and height of the box; if 0 they are interpreted as the input width and height.
           It defaults to 0.

       color, c
           Specify the color of the box to write. For the general syntax of this option, check the "Color" section in the ffmpeg-
           utils manual. If the special value "invert" is used, the box edge color is the same as the video with inverted luma.

       thickness, t
           The expression which sets the thickness of the box edge.  A value of "fill" will create a filled box. Default value is
           3.

           See below for the list of accepted constants.

       replace
           Applicable if the input has alpha. With value 1, the pixels of the painted box will overwrite the video's color and
           alpha pixels.  Default is 0, which composites the box onto the input, leaving the video's alpha intact.

       The parameters for x, y, w and h and t are expressions containing the following constants:

       dar The input display aspect ratio, it is the same as (w / h) * sar.

       hsub
       vsub
           horizontal and vertical chroma subsample values. For example for the pixel format "yuv422p" hsub is 2 and vsub is 1.

       in_h, ih
       in_w, iw
           The input width and height.

       sar The input sample aspect ratio.

       x
       y   The x and y offset coordinates where the box is drawn.

       w
       h   The width and height of the drawn box.

       box_source
           Box source can be set as side_data_detection_bboxes if you want to use box data in detection bboxes of side data.

           If box_source is set, the x, y, width and height will be ignored and still use box data in detection bboxes of side
           data. So please do not use this parameter if you were not sure about the box source.

       t   The thickness of the drawn box.

           These constants allow the x, y, w, h and t expressions to refer to each other, so you may for example specify "y=x/dar"
           or "h=w/dar".

       Examples

       •   Draw a black box around the edge of the input image:

                   drawbox

       •   Draw a box with color red and an opacity of 50%:

                   drawbox=10:20:200:60:red@0.5

           The previous example can be specified as:

                   drawbox=x=10:y=20:w=200:h=60:color=red@0.5

       •   Fill the box with pink color:

                   drawbox=x=10:y=10:w=100:h=100:color=pink@0.5:t=fill

       •   Draw a 2-pixel red 2.40:1 mask:

                   drawbox=x=-t:y=0.5*(ih-iw/2.4)-t:w=iw+t*2:h=iw/2.4+t*2:t=2:c=red

       Commands

       This filter supports same commands as options.  The command accepts the same syntax of the corresponding option.

       If the specified expression is not valid, it is kept at its current value.

   drawgraph
       Draw a graph using input video metadata.

       It accepts the following parameters:

       m1  Set 1st frame metadata key from which metadata values will be used to draw a graph.

       fg1 Set 1st foreground color expression.

       m2  Set 2nd frame metadata key from which metadata values will be used to draw a graph.

       fg2 Set 2nd foreground color expression.

       m3  Set 3rd frame metadata key from which metadata values will be used to draw a graph.

       fg3 Set 3rd foreground color expression.

       m4  Set 4th frame metadata key from which metadata values will be used to draw a graph.

       fg4 Set 4th foreground color expression.

       min Set minimal value of metadata value.

       max Set maximal value of metadata value.

       bg  Set graph background color. Default is white.

       mode
           Set graph mode.

           Available values for mode is:

           bar
           dot
           line

           Default is "line".

       slide
           Set slide mode.

           Available values for slide is:

           frame
               Draw new frame when right border is reached.

           replace
               Replace old columns with new ones.

           scroll
               Scroll from right to left.

           rscroll
               Scroll from left to right.

           picture
               Draw single picture.

           Default is "frame".

       size
           Set size of graph video. For the syntax of this option, check the "Video size" section in the ffmpeg-utils manual.  The
           default value is "900x256".

       rate, r
           Set the output frame rate. Default value is 25.

           The foreground color expressions can use the following variables:

           MIN Minimal value of metadata value.

           MAX Maximal value of metadata value.

           VAL Current metadata key value.

           The color is defined as 0xAABBGGRR.

       Example using metadata from signalstats filter:

               signalstats,drawgraph=lavfi.signalstats.YAVG:min=0:max=255

       Example using metadata from ebur128 filter:

               ebur128=metadata=1,adrawgraph=lavfi.r128.M:min=-120:max=5

   drawgrid
       Draw a grid on the input image.

       It accepts the following parameters:

       x
       y   The expressions which specify the coordinates of some point of grid intersection (meant to configure offset). Both
           default to 0.

       width, w
       height, h
           The expressions which specify the width and height of the grid cell, if 0 they are interpreted as the input width and
           height, respectively, minus "thickness", so image gets framed. Default to 0.

       color, c
           Specify the color of the grid. For the general syntax of this option, check the "Color" section in the ffmpeg-utils
           manual. If the special value "invert" is used, the grid color is the same as the video with inverted luma.

       thickness, t
           The expression which sets the thickness of the grid line. Default value is 1.

           See below for the list of accepted constants.

       replace
           Applicable if the input has alpha. With 1 the pixels of the painted grid will overwrite the video's color and alpha
           pixels.  Default is 0, which composites the grid onto the input, leaving the video's alpha intact.

       The parameters for x, y, w and h and t are expressions containing the following constants:

       dar The input display aspect ratio, it is the same as (w / h) * sar.

       hsub
       vsub
           horizontal and vertical chroma subsample values. For example for the pixel format "yuv422p" hsub is 2 and vsub is 1.

       in_h, ih
       in_w, iw
           The input grid cell width and height.

       sar The input sample aspect ratio.

       x
       y   The x and y coordinates of some point of grid intersection (meant to configure offset).

       w
       h   The width and height of the drawn cell.

       t   The thickness of the drawn cell.

           These constants allow the x, y, w, h and t expressions to refer to each other, so you may for example specify "y=x/dar"
           or "h=w/dar".

       Examples

       •   Draw a grid with cell 100x100 pixels, thickness 2 pixels, with color red and an opacity of 50%:

                   drawgrid=width=100:height=100:thickness=2:color=red@0.5

       •   Draw a white 3x3 grid with an opacity of 50%:

                   drawgrid=w=iw/3:h=ih/3:t=2:c=white@0.5

       Commands

       This filter supports same commands as options.  The command accepts the same syntax of the corresponding option.

       If the specified expression is not valid, it is kept at its current value.

   drawtext
       Draw a text string or text from a specified file on top of a video, using the libfreetype library.

       To enable compilation of this filter, you need to configure FFmpeg with "--enable-libfreetype".  To enable default font
       fallback and the font option you need to configure FFmpeg with "--enable-libfontconfig".  To enable the text_shaping option,
       you need to configure FFmpeg with "--enable-libfribidi".

       Syntax

       It accepts the following parameters:

       box Used to draw a box around text using the background color.  The value must be either 1 (enable) or 0 (disable).  The
           default value of box is 0.

       boxborderw
           Set the width of the border to be drawn around the box using boxcolor.  The default value of boxborderw is 0.

       boxcolor
           The color to be used for drawing box around text. For the syntax of this option, check the "Color" section in the
           ffmpeg-utils manual.

           The default value of boxcolor is "white".

       line_spacing
           Set the line spacing in pixels of the border to be drawn around the box using box.  The default value of line_spacing is
           0.

       borderw
           Set the width of the border to be drawn around the text using bordercolor.  The default value of borderw is 0.

       bordercolor
           Set the color to be used for drawing border around text. For the syntax of this option, check the "Color" section in the
           ffmpeg-utils manual.

           The default value of bordercolor is "black".

       expansion
           Select how the text is expanded. Can be either "none", "strftime" (deprecated) or "normal" (default). See the
           drawtext_expansion, Text expansion section below for details.

       basetime
           Set a start time for the count. Value is in microseconds. Only applied in the deprecated strftime expansion mode. To
           emulate in normal expansion mode use the "pts" function, supplying the start time (in seconds) as the second argument.

       fix_bounds
           If true, check and fix text coords to avoid clipping.

       fontcolor
           The color to be used for drawing fonts. For the syntax of this option, check the "Color" section in the ffmpeg-utils
           manual.

           The default value of fontcolor is "black".

       fontcolor_expr
           String which is expanded the same way as text to obtain dynamic fontcolor value. By default this option has empty value
           and is not processed. When this option is set, it overrides fontcolor option.

       font
           The font family to be used for drawing text. By default Sans.

       fontfile
           The font file to be used for drawing text. The path must be included.  This parameter is mandatory if the fontconfig
           support is disabled.

       alpha
           Draw the text applying alpha blending. The value can be a number between 0.0 and 1.0.  The expression accepts the same
           variables x, y as well.  The default value is 1.  Please see fontcolor_expr.

       fontsize
           The font size to be used for drawing text.  The default value of fontsize is 16.

       text_shaping
           If set to 1, attempt to shape the text (for example, reverse the order of right-to-left text and join Arabic characters)
           before drawing it.  Otherwise, just draw the text exactly as given.  By default 1 (if supported).

       ft_load_flags
           The flags to be used for loading the fonts.

           The flags map the corresponding flags supported by libfreetype, and are a combination of the following values:

           default
           no_scale
           no_hinting
           render
           no_bitmap
           vertical_layout
           force_autohint
           crop_bitmap
           pedantic
           ignore_global_advance_width
           no_recurse
           ignore_transform
           monochrome
           linear_design
           no_autohint

           Default value is "default".

           For more information consult the documentation for the FT_LOAD_* libfreetype flags.

       shadowcolor
           The color to be used for drawing a shadow behind the drawn text. For the syntax of this option, check the "Color"
           section in the ffmpeg-utils manual.

           The default value of shadowcolor is "black".

       shadowx
       shadowy
           The x and y offsets for the text shadow position with respect to the position of the text. They can be either positive
           or negative values. The default value for both is "0".

       start_number
           The starting frame number for the n/frame_num variable. The default value is "0".

       tabsize
           The size in number of spaces to use for rendering the tab.  Default value is 4.

       timecode
           Set the initial timecode representation in "hh:mm:ss[:;.]ff" format. It can be used with or without text parameter.
           timecode_rate option must be specified.

       timecode_rate, rate, r
           Set the timecode frame rate (timecode only). Value will be rounded to nearest integer. Minimum value is "1".  Drop-frame
           timecode is supported for frame rates 30 & 60.

       tc24hmax
           If set to 1, the output of the timecode option will wrap around at 24 hours.  Default is 0 (disabled).

       text
           The text string to be drawn. The text must be a sequence of UTF-8 encoded characters.  This parameter is mandatory if no
           file is specified with the parameter textfile.

       textfile
           A text file containing text to be drawn. The text must be a sequence of UTF-8 encoded characters.

           This parameter is mandatory if no text string is specified with the parameter text.

           If both text and textfile are specified, an error is thrown.

       text_source
           Text source should be set as side_data_detection_bboxes if you want to use text data in detection bboxes of side data.

           If text source is set, text and textfile will be ignored and still use text data in detection bboxes of side data. So
           please do not use this parameter if you are not sure about the text source.

       reload
           The textfile will be reloaded at specified frame interval.  Be sure to update textfile atomically, or it may be read
           partially, or even fail.  Range is 0 to INT_MAX. Default is 0.

       x
       y   The expressions which specify the offsets where text will be drawn within the video frame. They are relative to the
           top/left border of the output image.

           The default value of x and y is "0".

           See below for the list of accepted constants and functions.

       The parameters for x and y are expressions containing the following constants and functions:

       dar input display aspect ratio, it is the same as (w / h) * sar

       hsub
       vsub
           horizontal and vertical chroma subsample values. For example for the pixel format "yuv422p" hsub is 2 and vsub is 1.

       line_h, lh
           the height of each text line

       main_h, h, H
           the input height

       main_w, w, W
           the input width

       max_glyph_a, ascent
           the maximum distance from the baseline to the highest/upper grid coordinate used to place a glyph outline point, for all
           the rendered glyphs.  It is a positive value, due to the grid's orientation with the Y axis upwards.

       max_glyph_d, descent
           the maximum distance from the baseline to the lowest grid coordinate used to place a glyph outline point, for all the
           rendered glyphs.  This is a negative value, due to the grid's orientation, with the Y axis upwards.

       max_glyph_h
           maximum glyph height, that is the maximum height for all the glyphs contained in the rendered text, it is equivalent to
           ascent - descent.

       max_glyph_w
           maximum glyph width, that is the maximum width for all the glyphs contained in the rendered text

       n   the number of input frame, starting from 0

       rand(min, max)
           return a random number included between min and max

       sar The input sample aspect ratio.

       t   timestamp expressed in seconds, NAN if the input timestamp is unknown

       text_h, th
           the height of the rendered text

       text_w, tw
           the width of the rendered text

       x
       y   the x and y offset coordinates where the text is drawn.

           These parameters allow the x and y expressions to refer to each other, so you can for example specify "y=x/dar".

       pict_type
           A one character description of the current frame's picture type.

       pkt_pos
           The current packet's position in the input file or stream (in bytes, from the start of the input). A value of -1
           indicates this info is not available.

       pkt_duration
           The current packet's duration, in seconds.

       pkt_size
           The current packet's size (in bytes).

       Text expansion

       If expansion is set to "strftime", the filter recognizes strftime() sequences in the provided text and expands them
       accordingly. Check the documentation of strftime(). This feature is deprecated.

       If expansion is set to "none", the text is printed verbatim.

       If expansion is set to "normal" (which is the default), the following expansion mechanism is used.

       The backslash character \, followed by any character, always expands to the second character.

       Sequences of the form "%{...}" are expanded. The text between the braces is a function name, possibly followed by arguments
       separated by ':'.  If the arguments contain special characters or delimiters (':' or '}'), they should be escaped.

       Note that they probably must also be escaped as the value for the text option in the filter argument string and as the
       filter argument in the filtergraph description, and possibly also for the shell, that makes up to four levels of escaping;
       using a text file avoids these problems.

       The following functions are available:

       expr, e
           The expression evaluation result.

           It must take one argument specifying the expression to be evaluated, which accepts the same constants and functions as
           the x and y values. Note that not all constants should be used, for example the text size is not known when evaluating
           the expression, so the constants text_w and text_h will have an undefined value.

       expr_int_format, eif
           Evaluate the expression's value and output as formatted integer.

           The first argument is the expression to be evaluated, just as for the expr function.  The second argument specifies the
           output format. Allowed values are x, X, d and u. They are treated exactly as in the "printf" function.  The third
           parameter is optional and sets the number of positions taken by the output.  It can be used to add padding with zeros
           from the left.

       gmtime
           The time at which the filter is running, expressed in UTC.  It can accept an argument: a strftime() format string.  The
           format string is extended to support the variable %[1-6]N which prints fractions of the second with optionally specified
           number of digits.

       localtime
           The time at which the filter is running, expressed in the local time zone.  It can accept an argument: a strftime()
           format string.  The format string is extended to support the variable %[1-6]N which prints fractions of the second with
           optionally specified number of digits.

       metadata
           Frame metadata. Takes one or two arguments.

           The first argument is mandatory and specifies the metadata key.

           The second argument is optional and specifies a default value, used when the metadata key is not found or empty.

           Available metadata can be identified by inspecting entries starting with TAG included within each frame section printed
           by running "ffprobe -show_frames".

           String metadata generated in filters leading to the drawtext filter are also available.

       n, frame_num
           The frame number, starting from 0.

       pict_type
           A one character description of the current picture type.

       pts The timestamp of the current frame.  It can take up to three arguments.

           The first argument is the format of the timestamp; it defaults to "flt" for seconds as a decimal number with microsecond
           accuracy; "hms" stands for a formatted [-]HH:MM:SS.mmm timestamp with millisecond accuracy.  "gmtime" stands for the
           timestamp of the frame formatted as UTC time; "localtime" stands for the timestamp of the frame formatted as local time
           zone time.

           The second argument is an offset added to the timestamp.

           If the format is set to "hms", a third argument "24HH" may be supplied to present the hour part of the formatted
           timestamp in 24h format (00-23).

           If the format is set to "localtime" or "gmtime", a third argument may be supplied: a strftime() format string.  By
           default, YYYY-MM-DD HH:MM:SS format will be used.

       Commands

       This filter supports altering parameters via commands:

       reinit
           Alter existing filter parameters.

           Syntax for the argument is the same as for filter invocation, e.g.

                   fontsize=56:fontcolor=green:text='Hello World'

           Full filter invocation with sendcmd would look like this:

                   sendcmd=c='56.0 drawtext reinit fontsize=56\:fontcolor=green\:text=Hello\\ World'

       If the entire argument can't be parsed or applied as valid values then the filter will continue with its existing
       parameters.

       Examples

       •   Draw "Test Text" with font FreeSerif, using the default values for the optional parameters.

                   drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSerif.ttf: text='Test Text'"

       •   Draw 'Test Text' with font FreeSerif of size 24 at position x=100 and y=50 (counting from the top-left corner of the
           screen), text is yellow with a red box around it. Both the text and the box have an opacity of 20%.

                   drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSerif.ttf: text='Test Text':\
                             x=100: y=50: fontsize=24: fontcolor=yellow@0.2: box=1: boxcolor=red@0.2"

           Note that the double quotes are not necessary if spaces are not used within the parameter list.

       •   Show the text at the center of the video frame:

                   drawtext="fontsize=30:fontfile=FreeSerif.ttf:text='hello world':x=(w-text_w)/2:y=(h-text_h)/2"

       •   Show the text at a random position, switching to a new position every 30 seconds:

                   drawtext="fontsize=30:fontfile=FreeSerif.ttf:text='hello world':x=if(eq(mod(t\,30)\,0)\,rand(0\,(w-text_w))\,x):y=if(eq(mod(t\,30)\,0)\,rand(0\,(h-text_h))\,y)"

       •   Show a text line sliding from right to left in the last row of the video frame. The file LONG_LINE is assumed to contain
           a single line with no newlines.

                   drawtext="fontsize=15:fontfile=FreeSerif.ttf:text=LONG_LINE:y=h-line_h:x=-50*t"

       •   Show the content of file CREDITS off the bottom of the frame and scroll up.

                   drawtext="fontsize=20:fontfile=FreeSerif.ttf:textfile=CREDITS:y=h-20*t"

       •   Draw a single green letter "g", at the center of the input video.  The glyph baseline is placed at half screen height.

                   drawtext="fontsize=60:fontfile=FreeSerif.ttf:fontcolor=green:text=g:x=(w-max_glyph_w)/2:y=h/2-ascent"

       •   Show text for 1 second every 3 seconds:

                   drawtext="fontfile=FreeSerif.ttf:fontcolor=white:x=100:y=x/dar:enable=lt(mod(t\,3)\,1):text='blink'"

       •   Use fontconfig to set the font. Note that the colons need to be escaped.

                   drawtext='fontfile=Linux Libertine O-40\:style=Semibold:text=FFmpeg'

       •   Draw "Test Text" with font size dependent on height of the video.

                   drawtext="text='Test Text': fontsize=h/30: x=(w-text_w)/2: y=(h-text_h*2)"

       •   Print the date of a real-time encoding (see strftime(3)):

                   drawtext='fontfile=FreeSans.ttf:text=%{localtime\:%a %b %d %Y}'

       •   Show text fading in and out (appearing/disappearing):

                   #!/bin/sh
                   DS=1.0 # display start
                   DE=10.0 # display end
                   FID=1.5 # fade in duration
                   FOD=5 # fade out duration
                   ffplay -f lavfi "color,drawtext=text=TEST:fontsize=50:fontfile=FreeSerif.ttf:fontcolor_expr=ff0000%{eif\\\\: clip(255*(1*between(t\\, $DS + $FID\\, $DE - $FOD) + ((t - $DS)/$FID)*between(t\\, $DS\\, $DS + $FID) + (-(t - $DE)/$FOD)*between(t\\, $DE - $FOD\\, $DE) )\\, 0\\, 255) \\\\: x\\\\: 2 }"

       •   Horizontally align multiple separate texts. Note that max_glyph_a and the fontsize value are included in the y offset.

                   drawtext=fontfile=FreeSans.ttf:text=DOG:fontsize=24:x=10:y=20+24-max_glyph_a,
                   drawtext=fontfile=FreeSans.ttf:text=cow:fontsize=24:x=80:y=20+24-max_glyph_a

       •   Plot special lavf.image2dec.source_basename metadata onto each frame if such metadata exists. Otherwise, plot the string
           "NA". Note that image2 demuxer must have option -export_path_metadata 1 for the special metadata fields to be available
           for filters.

                   drawtext="fontsize=20:fontcolor=white:fontfile=FreeSans.ttf:text='%{metadata\:lavf.image2dec.source_basename\:NA}':x=10:y=10"

       For more information about libfreetype, check: <http://www.freetype.org/>.

       For more information about fontconfig, check: <http://freedesktop.org/software/fontconfig/fontconfig-user.html>.

       For more information about libfribidi, check: <http://fribidi.org/>.

   edgedetect
       Detect and draw edges. The filter uses the Canny Edge Detection algorithm.

       The filter accepts the following options:

       low
       high
           Set low and high threshold values used by the Canny thresholding algorithm.

           The high threshold selects the "strong" edge pixels, which are then connected through 8-connectivity with the "weak"
           edge pixels selected by the low threshold.

           low and high threshold values must be chosen in the range [0,1], and low should be lesser or equal to high.

           Default value for low is "20/255", and default value for high is "50/255".

       mode
           Define the drawing mode.

           wires
               Draw white/gray wires on black background.

           colormix
               Mix the colors to create a paint/cartoon effect.

           canny
               Apply Canny edge detector on all selected planes.

           Default value is wires.

       planes
           Select planes for filtering. By default all available planes are filtered.

       Examples

       •   Standard edge detection with custom values for the hysteresis thresholding:

                   edgedetect=low=0.1:high=0.4

       •   Painting effect without thresholding:

                   edgedetect=mode=colormix:high=0

   elbg
       Apply a posterize effect using the ELBG (Enhanced LBG) algorithm.

       For each input image, the filter will compute the optimal mapping from the input to the output given the codebook length,
       that is the number of distinct output colors.

       This filter accepts the following options.

       codebook_length, l
           Set codebook length. The value must be a positive integer, and represents the number of distinct output colors. Default
           value is 256.

       nb_steps, n
           Set the maximum number of iterations to apply for computing the optimal mapping. The higher the value the better the
           result and the higher the computation time. Default value is 1.

       seed, s
           Set a random seed, must be an integer included between 0 and UINT32_MAX. If not specified, or if explicitly set to -1,
           the filter will try to use a good random seed on a best effort basis.

       pal8
           Set pal8 output pixel format. This option does not work with codebook length greater than 256. Default is disabled.

       use_alpha
           Include alpha values in the quantization calculation. Allows creating palettized output images (e.g. PNG8) with multiple
           alpha smooth blending.

   entropy
       Measure graylevel entropy in histogram of color channels of video frames.

       It accepts the following parameters:

       mode
           Can be either normal or diff. Default is normal.

           diff mode measures entropy of histogram delta values, absolute differences between neighbour histogram values.

   epx
       Apply the EPX magnification filter which is designed for pixel art.

       It accepts the following option:

       n   Set the scaling dimension: 2 for "2xEPX", 3 for "3xEPX".  Default is 3.

   eq
       Set brightness, contrast, saturation and approximate gamma adjustment.

       The filter accepts the following options:

       contrast
           Set the contrast expression. The value must be a float value in range "-1000.0" to 1000.0. The default value is "1".

       brightness
           Set the brightness expression. The value must be a float value in range "-1.0" to 1.0. The default value is "0".

       saturation
           Set the saturation expression. The value must be a float in range 0.0 to 3.0. The default value is "1".

       gamma
           Set the gamma expression. The value must be a float in range 0.1 to 10.0.  The default value is "1".

       gamma_r
           Set the gamma expression for red. The value must be a float in range 0.1 to 10.0. The default value is "1".

       gamma_g
           Set the gamma expression for green. The value must be a float in range 0.1 to 10.0. The default value is "1".

       gamma_b
           Set the gamma expression for blue. The value must be a float in range 0.1 to 10.0. The default value is "1".

       gamma_weight
           Set the gamma weight expression. It can be used to reduce the effect of a high gamma value on bright image areas, e.g.
           keep them from getting overamplified and just plain white. The value must be a float in range 0.0 to 1.0. A value of 0.0
           turns the gamma correction all the way down while 1.0 leaves it at its full strength. Default is "1".

       eval
           Set when the expressions for brightness, contrast, saturation and gamma expressions are evaluated.

           It accepts the following values:

           init
               only evaluate expressions once during the filter initialization or when a command is processed

           frame
               evaluate expressions for each incoming frame

           Default value is init.

       The expressions accept the following parameters:

       n   frame count of the input frame starting from 0

       pos byte position of the corresponding packet in the input file, NAN if unspecified

       r   frame rate of the input video, NAN if the input frame rate is unknown

       t   timestamp expressed in seconds, NAN if the input timestamp is unknown

       Commands

       The filter supports the following commands:

       contrast
           Set the contrast expression.

       brightness
           Set the brightness expression.

       saturation
           Set the saturation expression.

       gamma
           Set the gamma expression.

       gamma_r
           Set the gamma_r expression.

       gamma_g
           Set gamma_g expression.

       gamma_b
           Set gamma_b expression.

       gamma_weight
           Set gamma_weight expression.

           The command accepts the same syntax of the corresponding option.

           If the specified expression is not valid, it is kept at its current value.

   erosion
       Apply erosion effect to the video.

       This filter replaces the pixel by the local(3x3) minimum.

       It accepts the following options:

       threshold0
       threshold1
       threshold2
       threshold3
           Limit the maximum change for each plane, default is 65535.  If 0, plane will remain unchanged.

       coordinates
           Flag which specifies the pixel to refer to. Default is 255 i.e. all eight pixels are used.

           Flags to local 3x3 coordinates maps like this:

               1 2 3
               4   5
               6 7 8

       Commands

       This filter supports the all above options as commands.

   estdif
       Deinterlace the input video ("estdif" stands for "Edge Slope Tracing Deinterlacing Filter").

       Spatial only filter that uses edge slope tracing algorithm to interpolate missing lines.  It accepts the following
       parameters:

       mode
           The interlacing mode to adopt. It accepts one of the following values:

           frame
               Output one frame for each frame.

           field
               Output one frame for each field.

           The default value is "field".

       parity
           The picture field parity assumed for the input interlaced video. It accepts one of the following values:

           tff Assume the top field is first.

           bff Assume the bottom field is first.

           auto
               Enable automatic detection of field parity.

           The default value is "auto".  If the interlacing is unknown or the decoder does not export this information, top field
           first will be assumed.

       deint
           Specify which frames to deinterlace. Accepts one of the following values:

           all Deinterlace all frames.

           interlaced
               Only deinterlace frames marked as interlaced.

           The default value is "all".

       rslope
           Specify the search radius for edge slope tracing. Default value is 1.  Allowed range is from 1 to 15.

       redge
           Specify the search radius for best edge matching. Default value is 2.  Allowed range is from 0 to 15.

       ecost
           Specify the edge cost for edge matching. Default value is 1.0.  Allowed range is from 0 to 9.

       mcost
           Specify the middle cost for edge matching. Default value is 0.5.  Allowed range is from 0 to 1.

       dcost
           Specify the distance cost for edge matching. Default value is 0.5.  Allowed range is from 0 to 1.

       interp
           Specify the interpolation used. Default is 4-point interpolation. It accepts one of the following values:

           2p  Two-point interpolation.

           4p  Four-point interpolation.

           6p  Six-point interpolation.

       Commands

       This filter supports same commands as options.

   exposure
       Adjust exposure of the video stream.

       The filter accepts the following options:

       exposure
           Set the exposure correction in EV. Allowed range is from -3.0 to 3.0 EV Default value is 0 EV.

       black
           Set the black level correction. Allowed range is from -1.0 to 1.0.  Default value is 0.

       Commands

       This filter supports same commands as options.

   extractplanes
       Extract color channel components from input video stream into separate grayscale video streams.

       The filter accepts the following option:

       planes
           Set plane(s) to extract.

           Available values for planes are:

           y
           u
           v
           a
           r
           g
           b

           Choosing planes not available in the input will result in an error.  That means you cannot select "r", "g", "b" planes
           with "y", "u", "v" planes at same time.

       Examples

       •   Extract luma, u and v color channel component from input video frame into 3 grayscale outputs:

                   ffmpeg -i video.avi -filter_complex 'extractplanes=y+u+v[y][u][v]' -map '[y]' y.avi -map '[u]' u.avi -map '[v]' v.avi

   fade
       Apply a fade-in/out effect to the input video.

       It accepts the following parameters:

       type, t
           The effect type can be either "in" for a fade-in, or "out" for a fade-out effect.  Default is "in".

       start_frame, s
           Specify the number of the frame to start applying the fade effect at. Default is 0.

       nb_frames, n
           The number of frames that the fade effect lasts. At the end of the fade-in effect, the output video will have the same
           intensity as the input video.  At the end of the fade-out transition, the output video will be filled with the selected
           color.  Default is 25.

       alpha
           If set to 1, fade only alpha channel, if one exists on the input.  Default value is 0.

       start_time, st
           Specify the timestamp (in seconds) of the frame to start to apply the fade effect. If both start_frame and start_time
           are specified, the fade will start at whichever comes last.  Default is 0.

       duration, d
           The number of seconds for which the fade effect has to last. At the end of the fade-in effect the output video will have
           the same intensity as the input video, at the end of the fade-out transition the output video will be filled with the
           selected color.  If both duration and nb_frames are specified, duration is used. Default is 0 (nb_frames is used by
           default).

       color, c
           Specify the color of the fade. Default is "black".

       Examples

       •   Fade in the first 30 frames of video:

                   fade=in:0:30

           The command above is equivalent to:

                   fade=t=in:s=0:n=30

       •   Fade out the last 45 frames of a 200-frame video:

                   fade=out:155:45
                   fade=type=out:start_frame=155:nb_frames=45

       •   Fade in the first 25 frames and fade out the last 25 frames of a 1000-frame video:

                   fade=in:0:25, fade=out:975:25

       •   Make the first 5 frames yellow, then fade in from frame 5-24:

                   fade=in:5:20:color=yellow

       •   Fade in alpha over first 25 frames of video:

                   fade=in:0:25:alpha=1

       •   Make the first 5.5 seconds black, then fade in for 0.5 seconds:

                   fade=t=in:st=5.5:d=0.5

   feedback
       Apply feedback video filter.

       This filter pass cropped input frames to 2nd output.  From there it can be filtered with other video filters.  After filter
       receives frame from 2nd input, that frame is combined on top of original frame from 1st input and passed to 1st output.

       The typical usage is filter only part of frame.

       The filter accepts the following options:

       x
       y   Set the top left crop position.

       w
       h   Set the crop size.

       Examples

       •   Blur only top left rectangular part of video frame size 100x100 with gblur filter.

                   [in][blurin]feedback=x=0:y=0:w=100:h=100[out][blurout];[blurout]gblur=8[blurin]

       •   Draw black box on top left part of video frame of size 100x100 with drawbox filter.

                   [in][blurin]feedback=x=0:y=0:w=100:h=100[out][blurout];[blurout]drawbox=x=0:y=0:w=100:h=100:t=100[blurin]

   fftdnoiz
       Denoise frames using 3D FFT (frequency domain filtering).

       The filter accepts the following options:

       sigma
           Set the noise sigma constant. This sets denoising strength.  Default value is 1. Allowed range is from 0 to 30.  Using
           very high sigma with low overlap may give blocking artifacts.

       amount
           Set amount of denoising. By default all detected noise is reduced.  Default value is 1. Allowed range is from 0 to 1.

       block
           Set size of block in pixels, Default is 32, can be 8 to 256.

       overlap
           Set block overlap. Default is 0.5. Allowed range is from 0.2 to 0.8.

       method
           Set denoising method. Default is "wiener", can also be "hard".

       prev
           Set number of previous frames to use for denoising. By default is set to 0.

       next
           Set number of next frames to to use for denoising. By default is set to 0.

       planes
           Set planes which will be filtered, by default are all available filtered except alpha.

   fftfilt
       Apply arbitrary expressions to samples in frequency domain

       dc_Y
           Adjust the dc value (gain) of the luma plane of the image. The filter accepts an integer value in range 0 to 1000. The
           default value is set to 0.

       dc_U
           Adjust the dc value (gain) of the 1st chroma plane of the image. The filter accepts an integer value in range 0 to 1000.
           The default value is set to 0.

       dc_V
           Adjust the dc value (gain) of the 2nd chroma plane of the image. The filter accepts an integer value in range 0 to 1000.
           The default value is set to 0.

       weight_Y
           Set the frequency domain weight expression for the luma plane.

       weight_U
           Set the frequency domain weight expression for the 1st chroma plane.

       weight_V
           Set the frequency domain weight expression for the 2nd chroma plane.

       eval
           Set when the expressions are evaluated.

           It accepts the following values:

           init
               Only evaluate expressions once during the filter initialization.

           frame
               Evaluate expressions for each incoming frame.

           Default value is init.

           The filter accepts the following variables:

       X
       Y   The coordinates of the current sample.

       W
       H   The width and height of the image.

       N   The number of input frame, starting from 0.

       WS
       HS  The size of FFT array for horizontal and vertical processing.

       Examples

       •   High-pass:

                   fftfilt=dc_Y=128:weight_Y='squish(1-(Y+X)/100)'

       •   Low-pass:

                   fftfilt=dc_Y=0:weight_Y='squish((Y+X)/100-1)'

       •   Sharpen:

                   fftfilt=dc_Y=0:weight_Y='1+squish(1-(Y+X)/100)'

       •   Blur:

                   fftfilt=dc_Y=0:weight_Y='exp(-4 * ((Y+X)/(W+H)))'

   field
       Extract a single field from an interlaced image using stride arithmetic to avoid wasting CPU time. The output frames are
       marked as non-interlaced.

       The filter accepts the following options:

       type
           Specify whether to extract the top (if the value is 0 or "top") or the bottom field (if the value is 1 or "bottom").

   fieldhint
       Create new frames by copying the top and bottom fields from surrounding frames supplied as numbers by the hint file.

       hint
           Set file containing hints: absolute/relative frame numbers.

           There must be one line for each frame in a clip. Each line must contain two numbers separated by the comma, optionally
           followed by "-" or "+".  Numbers supplied on each line of file can not be out of [N-1,N+1] where N is current frame
           number for "absolute" mode or out of [-1, 1] range for "relative" mode. First number tells from which frame to pick up
           top field and second number tells from which frame to pick up bottom field.

           If optionally followed by "+" output frame will be marked as interlaced, else if followed by "-" output frame will be
           marked as progressive, else it will be marked same as input frame.  If optionally followed by "t" output frame will use
           only top field, or in case of "b" it will use only bottom field.  If line starts with "#" or ";" that line is skipped.

       mode
           Can be item "absolute" or "relative" or "pattern". Default is "absolute".  The "pattern" mode is same as "relative"
           mode, except at last entry of file if there are more frames to process than "hint" file is seek back to start.

       Example of first several lines of "hint" file for "relative" mode:

               0,0 - # first frame
               1,0 - # second frame, use third's frame top field and second's frame bottom field
               1,0 - # third frame, use fourth's frame top field and third's frame bottom field
               1,0 -
               0,0 -
               0,0 -
               1,0 -
               1,0 -
               1,0 -
               0,0 -
               0,0 -
               1,0 -
               1,0 -
               1,0 -
               0,0 -

   fieldmatch
       Field matching filter for inverse telecine. It is meant to reconstruct the progressive frames from a telecined stream. The
       filter does not drop duplicated frames, so to achieve a complete inverse telecine "fieldmatch" needs to be followed by a
       decimation filter such as decimate in the filtergraph.

       The separation of the field matching and the decimation is notably motivated by the possibility of inserting a de-
       interlacing filter fallback between the two.  If the source has mixed telecined and real interlaced content, "fieldmatch"
       will not be able to match fields for the interlaced parts.  But these remaining combed frames will be marked as interlaced,
       and thus can be de-interlaced by a later filter such as yadif before decimation.

       In addition to the various configuration options, "fieldmatch" can take an optional second stream, activated through the
       ppsrc option. If enabled, the frames reconstruction will be based on the fields and frames from this second stream. This
       allows the first input to be pre-processed in order to help the various algorithms of the filter, while keeping the output
       lossless (assuming the fields are matched properly). Typically, a field-aware denoiser, or brightness/contrast adjustments
       can help.

       Note that this filter uses the same algorithms as TIVTC/TFM (AviSynth project) and VIVTC/VFM (VapourSynth project). The
       later is a light clone of TFM from which "fieldmatch" is based on. While the semantic and usage are very close, some
       behaviour and options names can differ.

       The decimate filter currently only works for constant frame rate input.  If your input has mixed telecined (30fps) and
       progressive content with a lower framerate like 24fps use the following filterchain to produce the necessary cfr stream:
       "dejudder,fps=30000/1001,fieldmatch,decimate".

       The filter accepts the following options:

       order
           Specify the assumed field order of the input stream. Available values are:

           auto
               Auto detect parity (use FFmpeg's internal parity value).

           bff Assume bottom field first.

           tff Assume top field first.

           Note that it is sometimes recommended not to trust the parity announced by the stream.

           Default value is auto.

       mode
           Set the matching mode or strategy to use. pc mode is the safest in the sense that it won't risk creating jerkiness due
           to duplicate frames when possible, but if there are bad edits or blended fields it will end up outputting combed frames
           when a good match might actually exist. On the other hand, pcn_ub mode is the most risky in terms of creating jerkiness,
           but will almost always find a good frame if there is one. The other values are all somewhere in between pc and pcn_ub in
           terms of risking jerkiness and creating duplicate frames versus finding good matches in sections with bad edits,
           orphaned fields, blended fields, etc.

           More details about p/c/n/u/b are available in p/c/n/u/b meaning section.

           Available values are:

           pc  2-way matching (p/c)

           pc_n
               2-way matching, and trying 3rd match if still combed (p/c + n)

           pc_u
               2-way matching, and trying 3rd match (same order) if still combed (p/c + u)

           pc_n_ub
               2-way matching, trying 3rd match if still combed, and trying 4th/5th matches if still combed (p/c + n + u/b)

           pcn 3-way matching (p/c/n)

           pcn_ub
               3-way matching, and trying 4th/5th matches if all 3 of the original matches are detected as combed (p/c/n + u/b)

           The parenthesis at the end indicate the matches that would be used for that mode assuming order=tff (and field on auto
           or top).

           In terms of speed pc mode is by far the fastest and pcn_ub is the slowest.

           Default value is pc_n.

       ppsrc
           Mark the main input stream as a pre-processed input, and enable the secondary input stream as the clean source to pick
           the fields from. See the filter introduction for more details. It is similar to the clip2 feature from VFM/TFM.

           Default value is 0 (disabled).

       field
           Set the field to match from. It is recommended to set this to the same value as order unless you experience matching
           failures with that setting. In certain circumstances changing the field that is used to match from can have a large
           impact on matching performance. Available values are:

           auto
               Automatic (same value as order).

           bottom
               Match from the bottom field.

           top Match from the top field.

           Default value is auto.

       mchroma
           Set whether or not chroma is included during the match comparisons. In most cases it is recommended to leave this
           enabled. You should set this to 0 only if your clip has bad chroma problems such as heavy rainbowing or other artifacts.
           Setting this to 0 could also be used to speed things up at the cost of some accuracy.

           Default value is 1.

       y0
       y1  These define an exclusion band which excludes the lines between y0 and y1 from being included in the field matching
           decision. An exclusion band can be used to ignore subtitles, a logo, or other things that may interfere with the
           matching. y0 sets the starting scan line and y1 sets the ending line; all lines in between y0 and y1 (including y0 and
           y1) will be ignored. Setting y0 and y1 to the same value will disable the feature.  y0 and y1 defaults to 0.

       scthresh
           Set the scene change detection threshold as a percentage of maximum change on the luma plane. Good values are in the
           "[8.0, 14.0]" range. Scene change detection is only relevant in case combmatch=sc.  The range for scthresh is "[0.0,
           100.0]".

           Default value is 12.0.

       combmatch
           When combatch is not none, "fieldmatch" will take into account the combed scores of matches when deciding what match to
           use as the final match. Available values are:

           none
               No final matching based on combed scores.

           sc  Combed scores are only used when a scene change is detected.

           full
               Use combed scores all the time.

           Default is sc.

       combdbg
           Force "fieldmatch" to calculate the combed metrics for certain matches and print them. This setting is known as micout
           in TFM/VFM vocabulary.  Available values are:

           none
               No forced calculation.

           pcn Force p/c/n calculations.

           pcnub
               Force p/c/n/u/b calculations.

           Default value is none.

       cthresh
           This is the area combing threshold used for combed frame detection. This essentially controls how "strong" or "visible"
           combing must be to be detected.  Larger values mean combing must be more visible and smaller values mean combing can be
           less visible or strong and still be detected. Valid settings are from "-1" (every pixel will be detected as combed) to
           255 (no pixel will be detected as combed). This is basically a pixel difference value. A good range is "[8, 12]".

           Default value is 9.

       chroma
           Sets whether or not chroma is considered in the combed frame decision.  Only disable this if your source has chroma
           problems (rainbowing, etc.) that are causing problems for the combed frame detection with chroma enabled. Actually,
           using chroma=0 is usually more reliable, except for the case where there is chroma only combing in the source.

           Default value is 0.

       blockx
       blocky
           Respectively set the x-axis and y-axis size of the window used during combed frame detection. This has to do with the
           size of the area in which combpel pixels are required to be detected as combed for a frame to be declared combed. See
           the combpel parameter description for more info.  Possible values are any number that is a power of 2 starting at 4 and
           going up to 512.

           Default value is 16.

       combpel
           The number of combed pixels inside any of the blocky by blockx size blocks on the frame for the frame to be detected as
           combed. While cthresh controls how "visible" the combing must be, this setting controls "how much" combing there must be
           in any localized area (a window defined by the blockx and blocky settings) on the frame. Minimum value is 0 and maximum
           is "blocky x blockx" (at which point no frames will ever be detected as combed). This setting is known as MI in TFM/VFM
           vocabulary.

           Default value is 80.

       p/c/n/u/b meaning

       p/c/n

       We assume the following telecined stream:

               Top fields:     1 2 2 3 4
               Bottom fields:  1 2 3 4 4

       The numbers correspond to the progressive frame the fields relate to. Here, the first two frames are progressive, the 3rd
       and 4th are combed, and so on.

       When "fieldmatch" is configured to run a matching from bottom (field=bottom) this is how this input stream get transformed:

               Input stream:
                               T     1 2 2 3 4
                               B     1 2 3 4 4   <-- matching reference

               Matches:              c c n n c

               Output stream:
                               T     1 2 3 4 4
                               B     1 2 3 4 4

       As a result of the field matching, we can see that some frames get duplicated.  To perform a complete inverse telecine, you
       need to rely on a decimation filter after this operation. See for instance the decimate filter.

       The same operation now matching from top fields (field=top) looks like this:

               Input stream:
                               T     1 2 2 3 4   <-- matching reference
                               B     1 2 3 4 4

               Matches:              c c p p c

               Output stream:
                               T     1 2 2 3 4
                               B     1 2 2 3 4

       In these examples, we can see what p, c and n mean; basically, they refer to the frame and field of the opposite parity:

       *<p matches the field of the opposite parity in the previous frame>
       *<c matches the field of the opposite parity in the current frame>
       *<n matches the field of the opposite parity in the next frame>

       u/b

       The u and b matching are a bit special in the sense that they match from the opposite parity flag. In the following
       examples, we assume that we are currently matching the 2nd frame (Top:2, bottom:2). According to the match, a 'x' is placed
       above and below each matched fields.

       With bottom matching (field=bottom):

               Match:           c         p           n          b          u

                                x       x               x        x          x
                 Top          1 2 2     1 2 2       1 2 2      1 2 2      1 2 2
                 Bottom       1 2 3     1 2 3       1 2 3      1 2 3      1 2 3
                                x         x           x        x              x

               Output frames:
                                2          1          2          2          2
                                2          2          2          1          3

       With top matching (field=top):

               Match:           c         p           n          b          u

                                x         x           x        x              x
                 Top          1 2 2     1 2 2       1 2 2      1 2 2      1 2 2
                 Bottom       1 2 3     1 2 3       1 2 3      1 2 3      1 2 3
                                x       x               x        x          x

               Output frames:
                                2          2          2          1          2
                                2          1          3          2          2

       Examples

       Simple IVTC of a top field first telecined stream:

               fieldmatch=order=tff:combmatch=none, decimate

       Advanced IVTC, with fallback on yadif for still combed frames:

               fieldmatch=order=tff:combmatch=full, yadif=deint=interlaced, decimate

   fieldorder
       Transform the field order of the input video.

       It accepts the following parameters:

       order
           The output field order. Valid values are tff for top field first or bff for bottom field first.

       The default value is tff.

       The transformation is done by shifting the picture content up or down by one line, and filling the remaining line with
       appropriate picture content.  This method is consistent with most broadcast field order converters.

       If the input video is not flagged as being interlaced, or it is already flagged as being of the required output field order,
       then this filter does not alter the incoming video.

       It is very useful when converting to or from PAL DV material, which is bottom field first.

       For example:

               ffmpeg -i in.vob -vf "fieldorder=bff" out.dv

   fifo, afifo
       Buffer input images and send them when they are requested.

       It is mainly useful when auto-inserted by the libavfilter framework.

       It does not take parameters.

   fillborders
       Fill borders of the input video, without changing video stream dimensions.  Sometimes video can have garbage at the four
       edges and you may not want to crop video input to keep size multiple of some number.

       This filter accepts the following options:

       left
           Number of pixels to fill from left border.

       right
           Number of pixels to fill from right border.

       top Number of pixels to fill from top border.

       bottom
           Number of pixels to fill from bottom border.

       mode
           Set fill mode.

           It accepts the following values:

           smear
               fill pixels using outermost pixels

           mirror
               fill pixels using mirroring (half sample symmetric)

           fixed
               fill pixels with constant value

           reflect
               fill pixels using reflecting (whole sample symmetric)

           wrap
               fill pixels using wrapping

           fade
               fade pixels to constant value

           margins
               fill pixels at top and bottom with weighted averages pixels near borders

           Default is smear.

       color
           Set color for pixels in fixed or fade mode. Default is black.

       Commands

       This filter supports same commands as options.  The command accepts the same syntax of the corresponding option.

       If the specified expression is not valid, it is kept at its current value.

   find_rect
       Find a rectangular object

       It accepts the following options:

       object
           Filepath of the object image, needs to be in gray8.

       threshold
           Detection threshold, default is 0.5.

       mipmaps
           Number of mipmaps, default is 3.

       xmin, ymin, xmax, ymax
           Specifies the rectangle in which to search.

       discard
           Discard frames where object is not detected. Default is disabled.

       Examples

       •   Cover a rectangular object by the supplied image of a given video using ffmpeg:

                   ffmpeg -i file.ts -vf find_rect=newref.pgm,cover_rect=cover.jpg:mode=cover new.mkv

   floodfill
       Flood area with values of same pixel components with another values.

       It accepts the following options:

       x   Set pixel x coordinate.

       y   Set pixel y coordinate.

       s0  Set source #0 component value.

       s1  Set source #1 component value.

       s2  Set source #2 component value.

       s3  Set source #3 component value.

       d0  Set destination #0 component value.

       d1  Set destination #1 component value.

       d2  Set destination #2 component value.

       d3  Set destination #3 component value.

   format
       Convert the input video to one of the specified pixel formats.  Libavfilter will try to pick one that is suitable as input
       to the next filter.

       It accepts the following parameters:

       pix_fmts
           A '|'-separated list of pixel format names, such as "pix_fmts=yuv420p|monow|rgb24".

       Examples

       •   Convert the input video to the yuv420p format

                   format=pix_fmts=yuv420p

           Convert the input video to any of the formats in the list

                   format=pix_fmts=yuv420p|yuv444p|yuv410p

   fps
       Convert the video to specified constant frame rate by duplicating or dropping frames as necessary.

       It accepts the following parameters:

       fps The desired output frame rate. It accepts expressions containing the following constants:

           source_fps
               The input's frame rate

           ntsc
               NTSC frame rate of "30000/1001"

           pal PAL frame rate of 25.0

           film
               Film frame rate of 24.0

           ntsc_film
               NTSC-film frame rate of "24000/1001"

           The default is 25.

       start_time
           Assume the first PTS should be the given value, in seconds. This allows for padding/trimming at the start of stream. By
           default, no assumption is made about the first frame's expected PTS, so no padding or trimming is done.  For example,
           this could be set to 0 to pad the beginning with duplicates of the first frame if a video stream starts after the audio
           stream or to trim any frames with a negative PTS.

       round
           Timestamp (PTS) rounding method.

           Possible values are:

           zero
               round towards 0

           inf round away from 0

           down
               round towards -infinity

           up  round towards +infinity

           near
               round to nearest

           The default is "near".

       eof_action
           Action performed when reading the last frame.

           Possible values are:

           round
               Use same timestamp rounding method as used for other frames.

           pass
               Pass through last frame if input duration has not been reached yet.

           The default is "round".

       Alternatively, the options can be specified as a flat string: fps[:start_time[:round]].

       See also the setpts filter.

       Examples

       •   A typical usage in order to set the fps to 25:

                   fps=fps=25

       •   Sets the fps to 24, using abbreviation and rounding method to round to nearest:

                   fps=fps=film:round=near

   framepack
       Pack two different video streams into a stereoscopic video, setting proper metadata on supported codecs. The two views
       should have the same size and framerate and processing will stop when the shorter video ends. Please note that you may
       conveniently adjust view properties with the scale and fps filters.

       It accepts the following parameters:

       format
           The desired packing format. Supported values are:

           sbs The views are next to each other (default).

           tab The views are on top of each other.

           lines
               The views are packed by line.

           columns
               The views are packed by column.

           frameseq
               The views are temporally interleaved.

       Some examples:

               # Convert left and right views into a frame-sequential video
               ffmpeg -i LEFT -i RIGHT -filter_complex framepack=frameseq OUTPUT

               # Convert views into a side-by-side video with the same output resolution as the input
               ffmpeg -i LEFT -i RIGHT -filter_complex [0:v]scale=w=iw/2[left],[1:v]scale=w=iw/2[right],[left][right]framepack=sbs OUTPUT

   framerate
       Change the frame rate by interpolating new video output frames from the source frames.

       This filter is not designed to function correctly with interlaced media. If you wish to change the frame rate of interlaced
       media then you are required to deinterlace before this filter and re-interlace after this filter.

       A description of the accepted options follows.

       fps Specify the output frames per second. This option can also be specified as a value alone. The default is 50.

       interp_start
           Specify the start of a range where the output frame will be created as a linear interpolation of two frames. The range
           is [0-255], the default is 15.

       interp_end
           Specify the end of a range where the output frame will be created as a linear interpolation of two frames. The range is
           [0-255], the default is 240.

       scene
           Specify the level at which a scene change is detected as a value between 0 and 100 to indicate a new scene; a low value
           reflects a low probability for the current frame to introduce a new scene, while a higher value means the current frame
           is more likely to be one.  The default is 8.2.

       flags
           Specify flags influencing the filter process.

           Available value for flags is:

           scene_change_detect, scd
               Enable scene change detection using the value of the option scene.  This flag is enabled by default.

   framestep
       Select one frame every N-th frame.

       This filter accepts the following option:

       step
           Select frame after every "step" frames.  Allowed values are positive integers higher than 0. Default value is 1.

   freezedetect
       Detect frozen video.

       This filter logs a message and sets frame metadata when it detects that the input video has no significant change in content
       during a specified duration.  Video freeze detection calculates the mean average absolute difference of all the components
       of video frames and compares it to a noise floor.

       The printed times and duration are expressed in seconds. The "lavfi.freezedetect.freeze_start" metadata key is set on the
       first frame whose timestamp equals or exceeds the detection duration and it contains the timestamp of the first frame of the
       freeze. The "lavfi.freezedetect.freeze_duration" and "lavfi.freezedetect.freeze_end" metadata keys are set on the first
       frame after the freeze.

       The filter accepts the following options:

       noise, n
           Set noise tolerance. Can be specified in dB (in case "dB" is appended to the specified value) or as a difference ratio
           between 0 and 1. Default is -60dB, or 0.001.

       duration, d
           Set freeze duration until notification (default is 2 seconds).

   freezeframes
       Freeze video frames.

       This filter freezes video frames using frame from 2nd input.

       The filter accepts the following options:

       first
           Set number of first frame from which to start freeze.

       last
           Set number of last frame from which to end freeze.

       replace
           Set number of frame from 2nd input which will be used instead of replaced frames.

   frei0r
       Apply a frei0r effect to the input video.

       To enable the compilation of this filter, you need to install the frei0r header and configure FFmpeg with "--enable-frei0r".

       It accepts the following parameters:

       filter_name
           The name of the frei0r effect to load. If the environment variable FREI0R_PATH is defined, the frei0r effect is searched
           for in each of the directories specified by the colon-separated list in FREI0R_PATH.  Otherwise, the standard frei0r
           paths are searched, in this order: HOME/.frei0r-1/lib/, /usr/local/lib/frei0r-1/, /usr/lib/frei0r-1/.

       filter_params
           A '|'-separated list of parameters to pass to the frei0r effect.

       A frei0r effect parameter can be a boolean (its value is either "y" or "n"), a double, a color (specified as R/G/B, where R,
       G, and B are floating point numbers between 0.0 and 1.0, inclusive) or a color description as specified in the "Color"
       section in the ffmpeg-utils manual, a position (specified as X/Y, where X and Y are floating point numbers) and/or a string.

       The number and types of parameters depend on the loaded effect. If an effect parameter is not specified, the default value
       is set.

       Examples

       •   Apply the distort0r effect, setting the first two double parameters:

                   frei0r=filter_name=distort0r:filter_params=0.5|0.01

       •   Apply the colordistance effect, taking a color as the first parameter:

                   frei0r=colordistance:0.2/0.3/0.4
                   frei0r=colordistance:violet
                   frei0r=colordistance:0x112233

       •   Apply the perspective effect, specifying the top left and top right image positions:

                   frei0r=perspective:0.2/0.2|0.8/0.2

       For more information, see <http://frei0r.dyne.org>

       Commands

       This filter supports the filter_params option as commands.

   fspp
       Apply fast and simple postprocessing. It is a faster version of spp.

       It splits (I)DCT into horizontal/vertical passes. Unlike the simple post- processing filter, one of them is performed once
       per block, not per pixel.  This allows for much higher speed.

       The filter accepts the following options:

       quality
           Set quality. This option defines the number of levels for averaging. It accepts an integer in the range 4-5. Default
           value is 4.

       qp  Force a constant quantization parameter. It accepts an integer in range 0-63.  If not set, the filter will use the QP
           from the video stream (if available).

       strength
           Set filter strength. It accepts an integer in range -15 to 32. Lower values mean more details but also more artifacts,
           while higher values make the image smoother but also blurrier. Default value is 0 X PSNR optimal.

       use_bframe_qp
           Enable the use of the QP from the B-Frames if set to 1. Using this option may cause flicker since the B-Frames have
           often larger QP. Default is 0 (not enabled).

   gblur
       Apply Gaussian blur filter.

       The filter accepts the following options:

       sigma
           Set horizontal sigma, standard deviation of Gaussian blur. Default is 0.5.

       steps
           Set number of steps for Gaussian approximation. Default is 1.

       planes
           Set which planes to filter. By default all planes are filtered.

       sigmaV
           Set vertical sigma, if negative it will be same as "sigma".  Default is "-1".

       Commands

       This filter supports same commands as options.  The command accepts the same syntax of the corresponding option.

       If the specified expression is not valid, it is kept at its current value.

   geq
       Apply generic equation to each pixel.

       The filter accepts the following options:

       lum_expr, lum
           Set the luminance expression.

       cb_expr, cb
           Set the chrominance blue expression.

       cr_expr, cr
           Set the chrominance red expression.

       alpha_expr, a
           Set the alpha expression.

       red_expr, r
           Set the red expression.

       green_expr, g
           Set the green expression.

       blue_expr, b
           Set the blue expression.

       The colorspace is selected according to the specified options. If one of the lum_expr, cb_expr, or cr_expr options is
       specified, the filter will automatically select a YCbCr colorspace. If one of the red_expr, green_expr, or blue_expr options
       is specified, it will select an RGB colorspace.

       If one of the chrominance expression is not defined, it falls back on the other one. If no alpha expression is specified it
       will evaluate to opaque value.  If none of chrominance expressions are specified, they will evaluate to the luminance
       expression.

       The expressions can use the following variables and functions:

       N   The sequential number of the filtered frame, starting from 0.

       X
       Y   The coordinates of the current sample.

       W
       H   The width and height of the image.

       SW
       SH  Width and height scale depending on the currently filtered plane. It is the ratio between the corresponding luma plane
           number of pixels and the current plane ones. E.g. for YUV4:2:0 the values are "1,1" for the luma plane, and "0.5,0.5"
           for chroma planes.

       T   Time of the current frame, expressed in seconds.

       p(x, y)
           Return the value of the pixel at location (x,y) of the current plane.

       lum(x, y)
           Return the value of the pixel at location (x,y) of the luminance plane.

       cb(x, y)
           Return the value of the pixel at location (x,y) of the blue-difference chroma plane. Return 0 if there is no such plane.

       cr(x, y)
           Return the value of the pixel at location (x,y) of the red-difference chroma plane. Return 0 if there is no such plane.

       r(x, y)
       g(x, y)
       b(x, y)
           Return the value of the pixel at location (x,y) of the red/green/blue component. Return 0 if there is no such component.

       alpha(x, y)
           Return the value of the pixel at location (x,y) of the alpha plane. Return 0 if there is no such plane.

       psum(x,y), lumsum(x, y), cbsum(x,y), crsum(x,y), rsum(x,y), gsum(x,y), bsum(x,y), alphasum(x,y)
           Sum of sample values in the rectangle from (0,0) to (x,y), this allows obtaining sums of samples within a rectangle. See
           the functions without the sum postfix.

       interpolation
           Set one of interpolation methods:

           nearest, n
           bilinear, b

           Default is bilinear.

       For functions, if x and y are outside the area, the value will be automatically clipped to the closer edge.

       Please note that this filter can use multiple threads in which case each slice will have its own expression state. If you
       want to use only a single expression state because your expressions depend on previous state then you should limit the
       number of filter threads to 1.

       Examples

       •   Flip the image horizontally:

                   geq=p(W-X\,Y)

       •   Generate a bidimensional sine wave, with angle "PI/3" and a wavelength of 100 pixels:

                   geq=128 + 100*sin(2*(PI/100)*(cos(PI/3)*(X-50*T) + sin(PI/3)*Y)):128:128

       •   Generate a fancy enigmatic moving light:

                   nullsrc=s=256x256,geq=random(1)/hypot(X-cos(N*0.07)*W/2-W/2\,Y-sin(N*0.09)*H/2-H/2)^2*1000000*sin(N*0.02):128:128

       •   Generate a quick emboss effect:

                   format=gray,geq=lum_expr='(p(X,Y)+(256-p(X-4,Y-4)))/2'

       •   Modify RGB components depending on pixel position:

                   geq=r='X/W*r(X,Y)':g='(1-X/W)*g(X,Y)':b='(H-Y)/H*b(X,Y)'

       •   Create a radial gradient that is the same size as the input (also see the vignette filter):

                   geq=lum=255*gauss((X/W-0.5)*3)*gauss((Y/H-0.5)*3)/gauss(0)/gauss(0),format=gray

   gradfun
       Fix the banding artifacts that are sometimes introduced into nearly flat regions by truncation to 8-bit color depth.
       Interpolate the gradients that should go where the bands are, and dither them.

       It is designed for playback only.  Do not use it prior to lossy compression, because compression tends to lose the dither
       and bring back the bands.

       It accepts the following parameters:

       strength
           The maximum amount by which the filter will change any one pixel. This is also the threshold for detecting nearly flat
           regions. Acceptable values range from .51 to 64; the default value is 1.2. Out-of-range values will be clipped to the
           valid range.

       radius
           The neighborhood to fit the gradient to. A larger radius makes for smoother gradients, but also prevents the filter from
           modifying the pixels near detailed regions. Acceptable values are 8-32; the default value is 16. Out-of-range values
           will be clipped to the valid range.

       Alternatively, the options can be specified as a flat string: strength[:radius]

       Examples

       •   Apply the filter with a 3.5 strength and radius of 8:

                   gradfun=3.5:8

       •   Specify radius, omitting the strength (which will fall-back to the default value):

                   gradfun=radius=8

   graphmonitor
       Show various filtergraph stats.

       With this filter one can debug complete filtergraph.  Especially issues with links filling with queued frames.

       The filter accepts the following options:

       size, s
           Set video output size. Default is hd720.

       opacity, o
           Set video opacity. Default is 0.9. Allowed range is from 0 to 1.

       mode, m
           Set output mode, can be fulll or compact.  In compact mode only filters with some queued frames have displayed stats.

       flags, f
           Set flags which enable which stats are shown in video.

           Available values for flags are:

           queue
               Display number of queued frames in each link.

           frame_count_in
               Display number of frames taken from filter.

           frame_count_out
               Display number of frames given out from filter.

           frame_count_delta
               Display delta number of frames between above two values.

           pts Display current filtered frame pts.

           pts_delta
               Display pts delta between current and previous frame.

           time
               Display current filtered frame time.

           time_delta
               Display time delta between current and previous frame.

           timebase
               Display time base for filter link.

           format
               Display used format for filter link.

           size
               Display video size or number of audio channels in case of audio used by filter link.

           rate
               Display video frame rate or sample rate in case of audio used by filter link.

           eof Display link output status.

           sample_count_in
               Display number of samples taken from filter.

           sample_count_out
               Display number of samples given out from filter.

           sample_count_delta
               Display delta number of samples between above two values.

       rate, r
           Set upper limit for video rate of output stream, Default value is 25.  This guarantee that output video frame rate will
           not be higher than this value.

   grayworld
       A color constancy filter that applies color correction based on the grayworld assumption

       See: <https://www.researchgate.net/publication/275213614_A_New_Color_Correction_Method_for_Underwater_Imaging>

       The algorithm  uses linear light, so input data should be linearized beforehand (and possibly correctly tagged).

               ffmpeg -i INPUT -vf zscale=transfer=linear,grayworld,zscale=transfer=bt709,format=yuv420p OUTPUT

   greyedge
       A color constancy variation filter which estimates scene illumination via grey edge algorithm and corrects the scene colors
       accordingly.

       See: <https://staff.science.uva.nl/th.gevers/pub/GeversTIP07.pdf>

       The filter accepts the following options:

       difford
           The order of differentiation to be applied on the scene. Must be chosen in the range [0,2] and default value is 1.

       minknorm
           The Minkowski parameter to be used for calculating the Minkowski distance. Must be chosen in the range [0,20] and
           default value is 1. Set to 0 for getting max value instead of calculating Minkowski distance.

       sigma
           The standard deviation of Gaussian blur to be applied on the scene. Must be chosen in the range [0,1024.0] and default
           value = 1. floor( sigma * break_off_sigma(3) ) can't be equal to 0 if difford is greater than 0.

       Examples

       •   Grey Edge:

                   greyedge=difford=1:minknorm=5:sigma=2

       •   Max Edge:

                   greyedge=difford=1:minknorm=0:sigma=2

   guided
       Apply guided filter for edge-preserving smoothing, dehazing and so on.

       The filter accepts the following options:

       radius
           Set the box radius in pixels.  Allowed range is 1 to 20. Default is 3.

       eps Set regularization parameter (with square).  Allowed range is 0 to 1. Default is 0.01.

       mode
           Set filter mode. Can be "basic" or "fast".  Default is "basic".

       sub Set subsampling ratio for "fast" mode.  Range is 2 to 64. Default is 4.  No subsampling occurs in "basic" mode.

       guidance
           Set guidance mode. Can be "off" or "on". Default is "off".  If "off", single input is required.  If "on", two inputs of
           the same resolution and pixel format are required.  The second input serves as the guidance.

       planes
           Set planes to filter. Default is first only.

       Commands

       This filter supports the all above options as commands.

       Examples

       •   Edge-preserving smoothing with guided filter:

                   ffmpeg -i in.png -vf guided out.png

       •   Dehazing, structure-transferring filtering, detail enhancement with guided filter.  For the generation of guidance
           image, refer to paper "Guided Image Filtering".  See: <http://kaiminghe.com/publications/pami12guidedfilter.pdf>.

                   ffmpeg -i in.png -i guidance.png -filter_complex guided=guidance=on out.png

   haldclut
       Apply a Hald CLUT to a video stream.

       First input is the video stream to process, and second one is the Hald CLUT.  The Hald CLUT input can be a simple picture or
       a complete video stream.

       The filter accepts the following options:

       clut
           Set which CLUT video frames will be processed from second input stream, can be first or all. Default is all.

       shortest
           Force termination when the shortest input terminates. Default is 0.

       repeatlast
           Continue applying the last CLUT after the end of the stream. A value of 0 disable the filter after the last frame of the
           CLUT is reached.  Default is 1.

       "haldclut" also has the same interpolation options as lut3d (both filters share the same internals).

       This filter also supports the framesync options.

       More information about the Hald CLUT can be found on Eskil Steenberg's website (Hald CLUT author) at
       <http://www.quelsolaar.com/technology/clut.html>.

       Commands

       This filter supports the "interp" option as commands.

       Workflow examples

       Hald CLUT video stream

       Generate an identity Hald CLUT stream altered with various effects:

               ffmpeg -f lavfi -i B<haldclutsrc>=8 -vf "hue=H=2*PI*t:s=sin(2*PI*t)+1, curves=cross_process" -t 10 -c:v ffv1 clut.nut

       Note: make sure you use a lossless codec.

       Then use it with "haldclut" to apply it on some random stream:

               ffmpeg -f lavfi -i mandelbrot -i clut.nut -filter_complex '[0][1] haldclut' -t 20 mandelclut.mkv

       The Hald CLUT will be applied to the 10 first seconds (duration of clut.nut), then the latest picture of that CLUT stream
       will be applied to the remaining frames of the "mandelbrot" stream.

       Hald CLUT with preview

       A Hald CLUT is supposed to be a squared image of "Level*Level*Level" by "Level*Level*Level" pixels. For a given Hald CLUT,
       FFmpeg will select the biggest possible square starting at the top left of the picture. The remaining padding pixels (bottom
       or right) will be ignored. This area can be used to add a preview of the Hald CLUT.

       Typically, the following generated Hald CLUT will be supported by the "haldclut" filter:

               ffmpeg -f lavfi -i B<haldclutsrc>=8 -vf "
                  pad=iw+320 [padded_clut];
                  smptebars=s=320x256, split [a][b];
                  [padded_clut][a] overlay=W-320:h, curves=color_negative [main];
                  [main][b] overlay=W-320" -frames:v 1 clut.png

       It contains the original and a preview of the effect of the CLUT: SMPTE color bars are displayed on the right-top, and below
       the same color bars processed by the color changes.

       Then, the effect of this Hald CLUT can be visualized with:

               ffplay input.mkv -vf "movie=clut.png, [in] haldclut"

   hflip
       Flip the input video horizontally.

       For example, to horizontally flip the input video with ffmpeg:

               ffmpeg -i in.avi -vf "hflip" out.avi

   histeq
       This filter applies a global color histogram equalization on a per-frame basis.

       It can be used to correct video that has a compressed range of pixel intensities.  The filter redistributes the pixel
       intensities to equalize their distribution across the intensity range. It may be viewed as an "automatically adjusting
       contrast filter". This filter is useful only for correcting degraded or poorly captured source video.

       The filter accepts the following options:

       strength
           Determine the amount of equalization to be applied.  As the strength is reduced, the distribution of pixel intensities
           more-and-more approaches that of the input frame. The value must be a float number in the range [0,1] and defaults to
           0.200.

       intensity
           Set the maximum intensity that can generated and scale the output values appropriately.  The strength should be set as
           desired and then the intensity can be limited if needed to avoid washing-out. The value must be a float number in the
           range [0,1] and defaults to 0.210.

       antibanding
           Set the antibanding level. If enabled the filter will randomly vary the luminance of output pixels by a small amount to
           avoid banding of the histogram. Possible values are "none", "weak" or "strong". It defaults to "none".

   histogram
       Compute and draw a color distribution histogram for the input video.

       The computed histogram is a representation of the color component distribution in an image.

       Standard histogram displays the color components distribution in an image.  Displays color graph for each color component.
       Shows distribution of the Y, U, V, A or R, G, B components, depending on input format, in the current frame. Below each
       graph a color component scale meter is shown.

       The filter accepts the following options:

       level_height
           Set height of level. Default value is 200.  Allowed range is [50, 2048].

       scale_height
           Set height of color scale. Default value is 12.  Allowed range is [0, 40].

       display_mode
           Set display mode.  It accepts the following values:

           stack
               Per color component graphs are placed below each other.

           parade
               Per color component graphs are placed side by side.

           overlay
               Presents information identical to that in the "parade", except that the graphs representing color components are
               superimposed directly over one another.

           Default is "stack".

       levels_mode
           Set mode. Can be either "linear", or "logarithmic".  Default is "linear".

       components
           Set what color components to display.  Default is 7.

       fgopacity
           Set foreground opacity. Default is 0.7.

       bgopacity
           Set background opacity. Default is 0.5.

       colors_mode
           Set colors mode.  It accepts the following values:

           whiteonblack
           blackonwhite
           whiteongray
           blackongray
           coloronblack
           coloronwhite
           colorongray
           blackoncolor
           whiteoncolor
           grayoncolor

           Default is "whiteonblack".

       Examples

       •   Calculate and draw histogram:

                   ffplay -i input -vf histogram

   hqdn3d
       This is a high precision/quality 3d denoise filter. It aims to reduce image noise, producing smooth images and making still
       images really still. It should enhance compressibility.

       It accepts the following optional parameters:

       luma_spatial
           A non-negative floating point number which specifies spatial luma strength.  It defaults to 4.0.

       chroma_spatial
           A non-negative floating point number which specifies spatial chroma strength.  It defaults to 3.0*luma_spatial/4.0.

       luma_tmp
           A floating point number which specifies luma temporal strength. It defaults to 6.0*luma_spatial/4.0.

       chroma_tmp
           A floating point number which specifies chroma temporal strength. It defaults to luma_tmp*chroma_spatial/luma_spatial.

       Commands

       This filter supports same commands as options.  The command accepts the same syntax of the corresponding option.

       If the specified expression is not valid, it is kept at its current value.

   hwdownload
       Download hardware frames to system memory.

       The input must be in hardware frames, and the output a non-hardware format.  Not all formats will be supported on the output
       - it may be necessary to insert an additional format filter immediately following in the graph to get the output in a
       supported format.

   hwmap
       Map hardware frames to system memory or to another device.

       This filter has several different modes of operation; which one is used depends on the input and output formats:

       •   Hardware frame input, normal frame output

           Map the input frames to system memory and pass them to the output.  If the original hardware frame is later required
           (for example, after overlaying something else on part of it), the hwmap filter can be used again in the next mode to
           retrieve it.

       •   Normal frame input, hardware frame output

           If the input is actually a software-mapped hardware frame, then unmap it - that is, return the original hardware frame.

           Otherwise, a device must be provided.  Create new hardware surfaces on that device for the output, then map them back to
           the software format at the input and give those frames to the preceding filter.  This will then act like the hwupload
           filter, but may be able to avoid an additional copy when the input is already in a compatible format.

       •   Hardware frame input and output

           A device must be supplied for the output, either directly or with the derive_device option.  The input and output
           devices must be of different types and compatible - the exact meaning of this is system-dependent, but typically it
           means that they must refer to the same underlying hardware context (for example, refer to the same graphics card).

           If the input frames were originally created on the output device, then unmap to retrieve the original frames.

           Otherwise, map the frames to the output device - create new hardware frames on the output corresponding to the frames on
           the input.

       The following additional parameters are accepted:

       mode
           Set the frame mapping mode.  Some combination of:

           read
               The mapped frame should be readable.

           write
               The mapped frame should be writeable.

           overwrite
               The mapping will always overwrite the entire frame.

               This may improve performance in some cases, as the original contents of the frame need not be loaded.

           direct
               The mapping must not involve any copying.

               Indirect mappings to copies of frames are created in some cases where either direct mapping is not possible or it
               would have unexpected properties.  Setting this flag ensures that the mapping is direct and will fail if that is not
               possible.

           Defaults to read+write if not specified.

       derive_device type
           Rather than using the device supplied at initialisation, instead derive a new device of type type from the device the
           input frames exist on.

       reverse
           In a hardware to hardware mapping, map in reverse - create frames in the sink and map them back to the source.  This may
           be necessary in some cases where a mapping in one direction is required but only the opposite direction is supported by
           the devices being used.

           This option is dangerous - it may break the preceding filter in undefined ways if there are any additional constraints
           on that filter's output.  Do not use it without fully understanding the implications of its use.

   hwupload
       Upload system memory frames to hardware surfaces.

       The device to upload to must be supplied when the filter is initialised.  If using ffmpeg, select the appropriate device
       with the -filter_hw_device option or with the derive_device option.  The input and output devices must be of different types
       and compatible - the exact meaning of this is system-dependent, but typically it means that they must refer to the same
       underlying hardware context (for example, refer to the same graphics card).

       The following additional parameters are accepted:

       derive_device type
           Rather than using the device supplied at initialisation, instead derive a new device of type type from the device the
           input frames exist on.

   hwupload_cuda
       Upload system memory frames to a CUDA device.

       It accepts the following optional parameters:

       device
           The number of the CUDA device to use

   hqx
       Apply a high-quality magnification filter designed for pixel art. This filter was originally created by Maxim Stepin.

       It accepts the following option:

       n   Set the scaling dimension: 2 for "hq2x", 3 for "hq3x" and 4 for "hq4x".  Default is 3.

   hstack
       Stack input videos horizontally.

       All streams must be of same pixel format and of same height.

       Note that this filter is faster than using overlay and pad filter to create same output.

       The filter accepts the following option:

       inputs
           Set number of input streams. Default is 2.

       shortest
           If set to 1, force the output to terminate when the shortest input terminates. Default value is 0.

   hsvhold
       Turns a certain HSV range into gray values.

       This filter measures color difference between set HSV color in options and ones measured in video stream. Depending on
       options, output colors can be changed to be gray or not.

       The filter accepts the following options:

       hue Set the hue value which will be used in color difference calculation.  Allowed range is from -360 to 360. Default value
           is 0.

       sat Set the saturation value which will be used in color difference calculation.  Allowed range is from -1 to 1. Default
           value is 0.

       val Set the value which will be used in color difference calculation.  Allowed range is from -1 to 1. Default value is 0.

       similarity
           Set similarity percentage with the key color.  Allowed range is from 0 to 1. Default value is 0.01.

           0.00001 matches only the exact key color, while 1.0 matches everything.

       blend
           Blend percentage.  Allowed range is from 0 to 1. Default value is 0.

           0.0 makes pixels either fully gray, or not gray at all.

           Higher values result in more gray pixels, with a higher gray pixel the more similar the pixels color is to the key
           color.

   hsvkey
       Turns a certain HSV range into transparency.

       This filter measures color difference between set HSV color in options and ones measured in video stream. Depending on
       options, output colors can be changed to transparent by adding alpha channel.

       The filter accepts the following options:

       hue Set the hue value which will be used in color difference calculation.  Allowed range is from -360 to 360. Default value
           is 0.

       sat Set the saturation value which will be used in color difference calculation.  Allowed range is from -1 to 1. Default
           value is 0.

       val Set the value which will be used in color difference calculation.  Allowed range is from -1 to 1. Default value is 0.

       similarity
           Set similarity percentage with the key color.  Allowed range is from 0 to 1. Default value is 0.01.

           0.00001 matches only the exact key color, while 1.0 matches everything.

       blend
           Blend percentage.  Allowed range is from 0 to 1. Default value is 0.

           0.0 makes pixels either fully transparent, or not transparent at all.

           Higher values result in semi-transparent pixels, with a higher transparency the more similar the pixels color is to the
           key color.

   hue
       Modify the hue and/or the saturation of the input.

       It accepts the following parameters:

       h   Specify the hue angle as a number of degrees. It accepts an expression, and defaults to "0".

       s   Specify the saturation in the [-10,10] range. It accepts an expression and defaults to "1".

       H   Specify the hue angle as a number of radians. It accepts an expression, and defaults to "0".

       b   Specify the brightness in the [-10,10] range. It accepts an expression and defaults to "0".

       h and H are mutually exclusive, and can't be specified at the same time.

       The b, h, H and s option values are expressions containing the following constants:

       n   frame count of the input frame starting from 0

       pts presentation timestamp of the input frame expressed in time base units

       r   frame rate of the input video, NAN if the input frame rate is unknown

       t   timestamp expressed in seconds, NAN if the input timestamp is unknown

       tb  time base of the input video

       Examples

       •   Set the hue to 90 degrees and the saturation to 1.0:

                   hue=h=90:s=1

       •   Same command but expressing the hue in radians:

                   hue=H=PI/2:s=1

       •   Rotate hue and make the saturation swing between 0 and 2 over a period of 1 second:

                   hue="H=2*PI*t: s=sin(2*PI*t)+1"

       •   Apply a 3 seconds saturation fade-in effect starting at 0:

                   hue="s=min(t/3\,1)"

           The general fade-in expression can be written as:

                   hue="s=min(0\, max((t-START)/DURATION\, 1))"

       •   Apply a 3 seconds saturation fade-out effect starting at 5 seconds:

                   hue="s=max(0\, min(1\, (8-t)/3))"

           The general fade-out expression can be written as:

                   hue="s=max(0\, min(1\, (START+DURATION-t)/DURATION))"

       Commands

       This filter supports the following commands:

       b
       s
       h
       H   Modify the hue and/or the saturation and/or brightness of the input video.  The command accepts the same syntax of the
           corresponding option.

           If the specified expression is not valid, it is kept at its current value.

   huesaturation
       Apply hue-saturation-intensity adjustments to input video stream.

       This filter operates in RGB colorspace.

       This filter accepts the following options:

       hue Set the hue shift in degrees to apply. Default is 0.  Allowed range is from -180 to 180.

       saturation
           Set the saturation shift. Default is 0.  Allowed range is from -1 to 1.

       intensity
           Set the intensity shift. Default is 0.  Allowed range is from -1 to 1.

       colors
           Set which primary and complementary colors are going to be adjusted.  This options is set by providing one or multiple
           values.  This can select multiple colors at once. By default all colors are selected.

           r   Adjust reds.

           y   Adjust yellows.

           g   Adjust greens.

           c   Adjust cyans.

           b   Adjust blues.

           m   Adjust magentas.

           a   Adjust all colors.

       strength
           Set strength of filtering. Allowed range is from 0 to 100.  Default value is 1.

       rw, gw, bw
           Set weight for each RGB component. Allowed range is from 0 to 1.  By default is set to 0.333, 0.334, 0.333.  Those
           options are used in saturation and lightess processing.

       lightness
           Set preserving lightness, by default is disabled.  Adjusting hues can change lightness from original RGB triplet, with
           this option enabled lightness is kept at same value.

   hysteresis
       Grow first stream into second stream by connecting components.  This makes it possible to build more robust edge masks.

       This filter accepts the following options:

       planes
           Set which planes will be processed as bitmap, unprocessed planes will be copied from first stream.  By default value
           0xf, all planes will be processed.

       threshold
           Set threshold which is used in filtering. If pixel component value is higher than this value filter algorithm for
           connecting components is activated.  By default value is 0.

       The "hysteresis" filter also supports the framesync options.

   iccdetect
       Detect the colorspace  from an embedded ICC profile (if present), and update the frame's tags accordingly.

       This filter accepts the following options:

       force
           If true, the frame's existing colorspace tags will always be overridden by values detected from an ICC profile.
           Otherwise, they will only be assigned if they contain "unknown". Enabled by default.

   iccgen
       Generate ICC profiles and attach them to frames.

       This filter accepts the following options:

       color_primaries
       color_trc
           Configure the colorspace that the ICC profile will be generated for. The default value of "auto" infers the value from
           the input frame's metadata, defaulting to BT.709/sRGB as appropriate.

           See the setparams filter for a list of possible values, but note that "unknown" are not valid values for this filter.

       force
           If true, an ICC profile will be generated even if it would overwrite an already existing ICC profile. Disabled by
           default.

   identity
       Obtain the identity score between two input videos.

       This filter takes two input videos.

       Both input videos must have the same resolution and pixel format for this filter to work correctly. Also it assumes that
       both inputs have the same number of frames, which are compared one by one.

       The obtained per component, average, min and max identity score is printed through the logging system.

       The filter stores the calculated identity scores of each frame in frame metadata.

       In the below example the input file main.mpg being processed is compared with the reference file ref.mpg.

               ffmpeg -i main.mpg -i ref.mpg -lavfi identity -f null -

   idet
       Detect video interlacing type.

       This filter tries to detect if the input frames are interlaced, progressive, top or bottom field first. It will also try to
       detect fields that are repeated between adjacent frames (a sign of telecine).

       Single frame detection considers only immediately adjacent frames when classifying each frame.  Multiple frame detection
       incorporates the classification history of previous frames.

       The filter will log these metadata values:

       single.current_frame
           Detected type of current frame using single-frame detection. One of: ``tff'' (top field first), ``bff'' (bottom field
           first), ``progressive'', or ``undetermined''

       single.tff
           Cumulative number of frames detected as top field first using single-frame detection.

       multiple.tff
           Cumulative number of frames detected as top field first using multiple-frame detection.

       single.bff
           Cumulative number of frames detected as bottom field first using single-frame detection.

       multiple.current_frame
           Detected type of current frame using multiple-frame detection. One of: ``tff'' (top field first), ``bff'' (bottom field
           first), ``progressive'', or ``undetermined''

       multiple.bff
           Cumulative number of frames detected as bottom field first using multiple-frame detection.

       single.progressive
           Cumulative number of frames detected as progressive using single-frame detection.

       multiple.progressive
           Cumulative number of frames detected as progressive using multiple-frame detection.

       single.undetermined
           Cumulative number of frames that could not be classified using single-frame detection.

       multiple.undetermined
           Cumulative number of frames that could not be classified using multiple-frame detection.

       repeated.current_frame
           Which field in the current frame is repeated from the last. One of ``neither'', ``top'', or ``bottom''.

       repeated.neither
           Cumulative number of frames with no repeated field.

       repeated.top
           Cumulative number of frames with the top field repeated from the previous frame's top field.

       repeated.bottom
           Cumulative number of frames with the bottom field repeated from the previous frame's bottom field.

       The filter accepts the following options:

       intl_thres
           Set interlacing threshold.

       prog_thres
           Set progressive threshold.

       rep_thres
           Threshold for repeated field detection.

       half_life
           Number of frames after which a given frame's contribution to the statistics is halved (i.e., it contributes only 0.5 to
           its classification). The default of 0 means that all frames seen are given full weight of 1.0 forever.

       analyze_interlaced_flag
           When this is not 0 then idet will use the specified number of frames to determine if the interlaced flag is accurate, it
           will not count undetermined frames.  If the flag is found to be accurate it will be used without any further
           computations, if it is found to be inaccurate it will be cleared without any further computations. This allows inserting
           the idet filter as a low computational method to clean up the interlaced flag

   il
       Deinterleave or interleave fields.

       This filter allows one to process interlaced images fields without deinterlacing them. Deinterleaving splits the input frame
       into 2 fields (so called half pictures). Odd lines are moved to the top half of the output image, even lines to the bottom
       half.  You can process (filter) them independently and then re-interleave them.

       The filter accepts the following options:

       luma_mode, l
       chroma_mode, c
       alpha_mode, a
           Available values for luma_mode, chroma_mode and alpha_mode are:

           none
               Do nothing.

           deinterleave, d
               Deinterleave fields, placing one above the other.

           interleave, i
               Interleave fields. Reverse the effect of deinterleaving.

           Default value is "none".

       luma_swap, ls
       chroma_swap, cs
       alpha_swap, as
           Swap luma/chroma/alpha fields. Exchange even & odd lines. Default value is 0.

       Commands

       This filter supports the all above options as commands.

   inflate
       Apply inflate effect to the video.

       This filter replaces the pixel by the local(3x3) average by taking into account only values higher than the pixel.

       It accepts the following options:

       threshold0
       threshold1
       threshold2
       threshold3
           Limit the maximum change for each plane, default is 65535.  If 0, plane will remain unchanged.

       Commands

       This filter supports the all above options as commands.

   interlace
       Simple interlacing filter from progressive contents. This interleaves upper (or lower) lines from odd frames with lower (or
       upper) lines from even frames, halving the frame rate and preserving image height.

                  Original        Original             New Frame
                  Frame 'j'      Frame 'j+1'             (tff)
                 ==========      ===========       ==================
                   Line 0  -------------------->    Frame 'j' Line 0
                   Line 1          Line 1  ---->   Frame 'j+1' Line 1
                   Line 2 --------------------->    Frame 'j' Line 2
                   Line 3          Line 3  ---->   Frame 'j+1' Line 3
                    ...             ...                   ...
               New Frame + 1 will be generated by Frame 'j+2' and Frame 'j+3' and so on

       It accepts the following optional parameters:

       scan
           This determines whether the interlaced frame is taken from the even (tff - default) or odd (bff) lines of the
           progressive frame.

       lowpass
           Vertical lowpass filter to avoid twitter interlacing and reduce moire patterns.

           0, off
               Disable vertical lowpass filter

           1, linear
               Enable linear filter (default)

           2, complex
               Enable complex filter. This will slightly less reduce twitter and moire but better retain detail and subjective
               sharpness impression.

   kerndeint
       Deinterlace input video by applying Donald Graft's adaptive kernel deinterling. Work on interlaced parts of a video to
       produce progressive frames.

       The description of the accepted parameters follows.

       thresh
           Set the threshold which affects the filter's tolerance when determining if a pixel line must be processed. It must be an
           integer in the range [0,255] and defaults to 10. A value of 0 will result in applying the process on every pixels.

       map Paint pixels exceeding the threshold value to white if set to 1.  Default is 0.

       order
           Set the fields order. Swap fields if set to 1, leave fields alone if 0. Default is 0.

       sharp
           Enable additional sharpening if set to 1. Default is 0.

       twoway
           Enable twoway sharpening if set to 1. Default is 0.

       Examples

       •   Apply default values:

                   kerndeint=thresh=10:map=0:order=0:sharp=0:twoway=0

       •   Enable additional sharpening:

                   kerndeint=sharp=1

       •   Paint processed pixels in white:

                   kerndeint=map=1

   kirsch
       Apply kirsch operator to input video stream.

       The filter accepts the following option:

       planes
           Set which planes will be processed, unprocessed planes will be copied.  By default value 0xf, all planes will be
           processed.

       scale
           Set value which will be multiplied with filtered result.

       delta
           Set value which will be added to filtered result.

       Commands

       This filter supports the all above options as commands.

   lagfun
       Slowly update darker pixels.

       This filter makes short flashes of light appear longer.  This filter accepts the following options:

       decay
           Set factor for decaying. Default is .95. Allowed range is from 0 to 1.

       planes
           Set which planes to filter. Default is all. Allowed range is from 0 to 15.

       Commands

       This filter supports the all above options as commands.

   lenscorrection
       Correct radial lens distortion

       This filter can be used to correct for radial distortion as can result from the use of wide angle lenses, and thereby re-
       rectify the image. To find the right parameters one can use tools available for example as part of opencv or simply trial-
       and-error.  To use opencv use the calibration sample (under samples/cpp) from the opencv sources and extract the k1 and k2
       coefficients from the resulting matrix.

       Note that effectively the same filter is available in the open-source tools Krita and Digikam from the KDE project.

       In contrast to the vignette filter, which can also be used to compensate lens errors, this filter corrects the distortion of
       the image, whereas vignette corrects the brightness distribution, so you may want to use both filters together in certain
       cases, though you will have to take care of ordering, i.e. whether vignetting should be applied before or after lens
       correction.

       Options

       The filter accepts the following options:

       cx  Relative x-coordinate of the focal point of the image, and thereby the center of the distortion. This value has a range
           [0,1] and is expressed as fractions of the image width. Default is 0.5.

       cy  Relative y-coordinate of the focal point of the image, and thereby the center of the distortion. This value has a range
           [0,1] and is expressed as fractions of the image height. Default is 0.5.

       k1  Coefficient of the quadratic correction term. This value has a range [-1,1]. 0 means no correction. Default is 0.

       k2  Coefficient of the double quadratic correction term. This value has a range [-1,1].  0 means no correction. Default is
           0.

       i   Set interpolation type. Can be "nearest" or "bilinear".  Default is "nearest".

       fc  Specify the color of the unmapped pixels. For the syntax of this option, check the "Color" section in the ffmpeg-utils
           manual. Default color is "black@0".

       The formula that generates the correction is:

       r_src = r_tgt * (1 + k1 * (r_tgt / r_0)^2 + k2 * (r_tgt / r_0)^4)

       where r_0 is halve of the image diagonal and r_src and r_tgt are the distances from the focal point in the source and target
       images, respectively.

       Commands

       This filter supports the all above options as commands.

   lensfun
       Apply lens correction via the lensfun library (<http://lensfun.sourceforge.net/>).

       The "lensfun" filter requires the camera make, camera model, and lens model to apply the lens correction. The filter will
       load the lensfun database and query it to find the corresponding camera and lens entries in the database. As long as these
       entries can be found with the given options, the filter can perform corrections on frames. Note that incomplete strings will
       result in the filter choosing the best match with the given options, and the filter will output the chosen camera and lens
       models (logged with level "info"). You must provide the make, camera model, and lens model as they are required.

       To obtain a list of available makes and models, leave out one or both of "make" and "model" options. The filter will send
       the full list to the log with level "INFO".  The first column is the make and the second column is the model.  To obtain a
       list of available lenses, set any values for make and model and leave out the "lens_model" option. The filter will send the
       full list of lenses in the log with level "INFO". The ffmpeg tool will exit after the list is printed.

       The filter accepts the following options:

       make
           The make of the camera (for example, "Canon"). This option is required.

       model
           The model of the camera (for example, "Canon EOS 100D"). This option is required.

       lens_model
           The model of the lens (for example, "Canon EF-S 18-55mm f/3.5-5.6 IS STM"). This option is required.

       db_path
           The full path to the lens database folder. If not set, the filter will attempt to load the database from the install
           path when the library was built. Default is unset.

       mode
           The type of correction to apply. The following values are valid options:

           vignetting
               Enables fixing lens vignetting.

           geometry
               Enables fixing lens geometry. This is the default.

           subpixel
               Enables fixing chromatic aberrations.

           vig_geo
               Enables fixing lens vignetting and lens geometry.

           vig_subpixel
               Enables fixing lens vignetting and chromatic aberrations.

           distortion
               Enables fixing both lens geometry and chromatic aberrations.

           all Enables all possible corrections.

       focal_length
           The focal length of the image/video (zoom; expected constant for video). For example, a 18--55mm lens has focal length
           range of [18--55], so a value in that range should be chosen when using that lens. Default 18.

       aperture
           The aperture of the image/video (expected constant for video). Note that aperture is only used for vignetting
           correction. Default 3.5.

       focus_distance
           The focus distance of the image/video (expected constant for video). Note that focus distance is only used for
           vignetting and only slightly affects the vignetting correction process. If unknown, leave it at the default value (which
           is 1000).

       scale
           The scale factor which is applied after transformation. After correction the video is no longer necessarily rectangular.
           This parameter controls how much of the resulting image is visible. The value 0 means that a value will be chosen
           automatically such that there is little or no unmapped area in the output image. 1.0 means that no additional scaling is
           done. Lower values may result in more of the corrected image being visible, while higher values may avoid unmapped areas
           in the output.

       target_geometry
           The target geometry of the output image/video. The following values are valid options:

           rectilinear (default)
           fisheye
           panoramic
           equirectangular
           fisheye_orthographic
           fisheye_stereographic
           fisheye_equisolid
           fisheye_thoby
       reverse
           Apply the reverse of image correction (instead of correcting distortion, apply it).

       interpolation
           The type of interpolation used when correcting distortion. The following values are valid options:

           nearest
           linear (default)
           lanczos

       Examples

       •   Apply lens correction with make "Canon", camera model "Canon EOS 100D", and lens model "Canon EF-S 18-55mm f/3.5-5.6 IS
           STM" with focal length of "18" and aperture of "8.0".

                   ffmpeg -i input.mov -vf lensfun=make=Canon:model="Canon EOS 100D":lens_model="Canon EF-S 18-55mm f/3.5-5.6 IS STM":focal_length=18:aperture=8 -c:v h264 -b:v 8000k output.mov

       •   Apply the same as before, but only for the first 5 seconds of video.

                   ffmpeg -i input.mov -vf lensfun=make=Canon:model="Canon EOS 100D":lens_model="Canon EF-S 18-55mm f/3.5-5.6 IS STM":focal_length=18:aperture=8:enable='lte(t\,5)' -c:v h264 -b:v 8000k output.mov

   libplacebo
       Flexible GPU-accelerated processing filter based on libplacebo (<https://code.videolan.org/videolan/libplacebo>). Note that
       this filter currently only accepts Vulkan input frames.

       Options

       The options for this filter are divided into the following sections:

       Output mode

       These options control the overall output mode. By default, libplacebo will try to preserve the source colorimetry and size
       as best as it can, but it will apply any embedded film grain, dolby vision metadata or anamorphic SAR present in source
       frames.

       w
       h   Set the output video dimension expression. Default value is the input dimension.

           Allows for the same expressions as the scale filter.

       format
           Set the output format override. If unset (the default), frames will be output in the same format as the respective input
           frames. Otherwise, format conversion will be performed.

       force_original_aspect_ratio
       force_divisible_by
           Work the same as the identical scale filter options.

       normalize_sar
           If enabled (the default), output frames will always have a pixel aspect ratio of 1:1. If disabled, any aspect ratio
           mismatches, including those from e.g.  anamorphic video sources, are forwarded to the output pixel aspect ratio.

       pad_crop_ratio
           Specifies a ratio (between 0.0 and 1.0) between padding and cropping when the input aspect ratio does not match the
           output aspect ratio and normalize_sar is in effect. The default of 0.0 always pads the content with black borders, while
           a value of 1.0 always crops off parts of the content. Intermediate values are possible, leading to a mix of the two
           approaches.

       colorspace
       color_primaries
       color_trc
       range
           Configure the colorspace that output frames will be delivered in. The default value of "auto" outputs frames in the same
           format as the input frames, leading to no change. For any other value, conversion will be performed.

           See the setparams filter for a list of possible values.

       apply_filmgrain
           Apply film grain (e.g. AV1 or H.274) if present in source frames, and strip it from the output. Enabled by default.

       apply_dolbyvision
           Apply Dolby Vision RPU metadata if present in source frames, and strip it from the output. Enabled by default. Note that
           Dolby Vision will always output BT.2020+PQ, overriding the usual input frame metadata. These will also be picked as the
           values of "auto" for the respective frame output options.

       Scaling

       The options in this section control how libplacebo performs upscaling and (if necessary) downscaling. Note that libplacebo
       will always internally operate on 4:4:4 content, so any sub-sampled chroma formats such as "yuv420p" will necessarily be
       upsampled and downsampled as part of the rendering process. That means scaling might be in effect even if the source and
       destination resolution are the same.

       upscaler
       downscaler
           Configure the filter kernel used for upscaling and downscaling. The respective defaults are "spline36" and "mitchell".
           For a full list of possible values, pass "help" to these options. The most important values are:

           none
               Forces the use of built-in GPU texture sampling (typically bilinear). Extremely fast but poor quality, especially
               when downscaling.

           bilinear
               Bilinear interpolation. Can generally be done for free on GPUs, except when doing so would lead to aliasing. Fast
               and low quality.

           nearest
               Nearest-neighbour interpolation. Sharp but highly aliasing.

           oversample
               Algorithm that looks visually similar to nearest-neighbour interpolation but tries to preserve pixel aspect ratio.
               Good for pixel art, since it results in minimal distortion of the artistic appearance.

           lanczos
               Standard sinc-sinc interpolation kernel.

           spline36
               Cubic spline approximation of lanczos. No difference in performance, but has very slightly less ringing.

           ewa_lanczos
               Elliptically weighted average version of lanczos, based on a jinc-sinc kernel.  This is also popularly referred to
               as just "Jinc scaling". Slow but very high quality.

           gaussian
               Gaussian kernel. Has certain ideal mathematical properties, but subjectively very blurry.

           mitchell
               Cubic BC spline with parameters recommended by Mitchell and Netravali. Very little ringing.

       lut_entries
           Configures the size of scaler LUTs, ranging from 1 to 256. The default of 0 will pick libplacebo's internal default,
           typically 64.

       antiringing
           Enables anti-ringing (for non-EWA filters). The value (between 0.0 and 1.0) configures the strength of the anti-ringing
           algorithm. May increase aliasing if set too high. Disabled by default.

       sigmoid
           Enable sigmoidal compression during upscaling. Reduces ringing slightly.  Enabled by default.

       Debanding

       Libplacebo comes with a built-in debanding filter that is good at counteracting many common sources of banding and blocking.
       Turning this on is highly recommended whenever quality is desired.

       deband
           Enable (fast) debanding algorithm. Disabled by default.

       deband_iterations
           Number of deband iterations of the debanding algorithm. Each iteration is performed with progressively increased radius
           (and diminished threshold).  Recommended values are in the range 1 to 4. Defaults to 1.

       deband_threshold
           Debanding filter strength. Higher numbers lead to more aggressive debanding.  Defaults to 4.0.

       deband_radius
           Debanding filter radius. A higher radius is better for slow gradients, while a lower radius is better for steep
           gradients. Defaults to 16.0.

       deband_grain
           Amount of extra output grain to add. Helps hide imperfections. Defaults to 6.0.

       Color adjustment

       A collection of subjective color controls. Not very rigorous, so the exact effect will vary somewhat depending on the input
       primaries and colorspace.

       brightness
           Brightness boost, between "-1.0" and 1.0. Defaults to 0.0.

       contrast
           Contrast gain, between 0.0 and 16.0. Defaults to 1.0.

       saturation
           Saturation gain, between 0.0 and 16.0. Defaults to 1.0.

       hue Hue shift in radians, between "-3.14" and 3.14. Defaults to 0.0. This will rotate the UV subvector, defaulting to BT.709
           coefficients for RGB inputs.

       gamma
           Gamma adjustment, between 0.0 and 16.0. Defaults to 1.0.

       cones
           Cone model to use for color blindness simulation. Accepts any combination of "l", "m" and "s". Here are some examples:

           m   Deuteranomaly / deuteranopia (affecting 3%-4% of the population)

           l   Protanomaly / protanopia (affecting 1%-2% of the population)

           l+m Monochromacy (very rare)

           l+m+s
               Achromatopsy (complete loss of daytime vision, extremely rare)

       cone-strength
           Gain factor for the cones specified by "cones", between 0.0 and 10.0. A value of 1.0 results in no change to color
           vision. A value of 0.0 (the default) simulates complete loss of those cones. Values above 1.0 result in exaggerating the
           differences between cones, which may help compensate for reduced color vision.

       Peak detection

       To help deal with sources that only have static HDR10 metadata (or no tagging whatsoever), libplacebo uses its own internal
       frame analysis compute shader to analyze source frames and adapt the tone mapping function in realtime. If this is too slow,
       or if exactly reproducible frame-perfect results are needed, it's recommended to turn this feature off.

       peak_detect
           Enable HDR peak detection. Ignores static MaxCLL/MaxFALL values in favor of dynamic detection from the input. Note that
           the detected values do not get written back to the output frames, they merely guide the internal tone mapping process.
           Enabled by default.

       smoothing_period
           Peak detection smoothing period, between 0.0 and 1000.0. Higher values result in peak detection becoming less responsive
           to changes in the input. Defaults to 100.0.

       minimum_peak
           Lower bound on the detected peak (relative to SDR white), between 0.0 and 100.0. Defaults to 1.0.

       scene_threshold_low
       scene_threshold_high
           Lower and upper thresholds for scene change detection. Expressed in a logarithmic scale between 0.0 and 100.0. Default
           to 5.5 and 10.0, respectively. Setting either to a negative value disables this functionality.

       overshoot
           Peak smoothing overshoot margin, between 0.0 and 1.0. Provides a safety margin to prevent clipping as a result of peak
           smoothing. Defaults to 0.05, corresponding to a margin of 5%.

       Tone mapping

       The options in this section control how libplacebo performs tone-mapping and gamut-mapping when dealing with mismatches
       between wide-gamut or HDR content.  In general, libplacebo relies on accurate source tagging and mastering display gamut
       information to produce the best results.

       intent
           Rendering intent to use when adapting between different primary color gamuts (after tone-mapping).

           perceptual
               Perceptual gamut mapping. Currently equivalent to relative colorimetric.

           relative
               Relative colorimetric. This is the default.

           absolute
               Absolute colorimetric.

           saturation
               Saturation mapping. Forcibly stretches the source gamut to the target gamut.

       gamut_mode
           How to handle out-of-gamut colors that can occur as a result of colorimetric gamut mapping.

           clip
               Do nothing, simply clip out-of-range colors to the RGB volume. This is the default.

           warn
               Highlight out-of-gamut pixels (by coloring them pink).

           darken
               Linearly reduces content brightness to preserves saturated details, followed by clipping the remaining out-of-gamut
               colors. As the name implies, this makes everything darker, but provides a good balance between preserving details
               and colors.

           desaturate
               Hard-desaturates out-of-gamut colors towards white, while preserving the luminance. Has a tendency to shift colors.

       tonemapping
           Tone-mapping algorithm to use. Available values are:

           auto
               Automatic selection based on internal heuristics. This is the default.

           clip
               Performs no tone-mapping, just clips out-of-range colors. Retains perfect color accuracy for in-range colors but
               completely destroys out-of-range information.  Does not perform any black point adaptation. Not configurable.

           bt.2390
               EETF from the ITU-R Report BT.2390, a hermite spline roll-off with linear segment. The knee point offset is
               configurable. Note that this parameter defaults to 1.0, rather than the value of 0.5 from the ITU-R spec.

           bt.2446a
               EETF from ITU-R Report BT.2446, method A. Designed for well-mastered HDR sources. Can be used for both forward and
               inverse tone mapping. Not configurable.

           spline
               Simple spline consisting of two polynomials, joined by a single pivot point.  The parameter gives the pivot point
               (in PQ space), defaulting to 0.30.  Can be used for both forward and inverse tone mapping.

           reinhard
               Simple non-linear, global tone mapping algorithm. The parameter specifies the local contrast coefficient at the
               display peak. Essentially, a parameter of 0.5 implies that the reference white will be about half as bright as when
               clipping. Defaults to 0.5, which results in the simplest formulation of this function.

           mobius
               Generalization of the reinhard tone mapping algorithm to support an additional linear slope near black. The tone
               mapping parameter indicates the trade-off between the linear section and the non-linear section. Essentially, for a
               given parameter x, every color value below x will be mapped linearly, while higher values get non-linearly tone-
               mapped. Values near 1.0 make this curve behave like "clip", while values near 0.0 make this curve behave like
               "reinhard". The default value is 0.3, which provides a good balance between colorimetric accuracy and preserving
               out-of-gamut details.

           hable
               Piece-wise, filmic tone-mapping algorithm developed by John Hable for use in Uncharted 2, inspired by a similar
               tone-mapping algorithm used by Kodak.  Popularized by its use in video games with HDR rendering. Preserves both dark
               and bright details very well, but comes with the drawback of changing the average brightness quite significantly.
               This is sort of similar to "reinhard" with parameter 0.24.

           gamma
               Fits a gamma (power) function to transfer between the source and target color spaces, effectively resulting in a
               perceptual hard-knee joining two roughly linear sections. This preserves details at all scales fairly accurately,
               but can result in an image with a muted or dull appearance. The parameter is used as the cutoff point, defaulting to
               0.5.

           linear
               Linearly stretches the input range to the output range, in PQ space. This will preserve all details accurately, but
               results in a significantly different average brightness. Can be used for inverse tone-mapping in addition to regular
               tone-mapping. The parameter can be used as an additional linear gain coefficient (defaulting to 1.0).

       tonemapping_param
           For tunable tone mapping functions, this parameter can be used to fine-tune the curve behavior. Refer to the
           documentation of "tonemapping". The default value of 0.0 is replaced by the curve's preferred default setting.

       tonemapping_mode
           This option determines how the tone mapping function specified by "tonemapping" is applied to the colors in a scene.
           Possible values are:

           auto
               Automatic selection based on internal heuristics. This is the default.

           rgb Apply the function per-channel in the RGB colorspace.  Per-channel tone-mapping in RGB. Guarantees no clipping and
               heavily desaturates the output, but distorts the colors quite significantly. Very similar to the "Hollywood" look
               and feel.

           max Tone-mapping is performed on the brightest component found in the signal. Good at preserving details in highlights,
               but has a tendency to crush blacks.

           hybrid
               Tone-map per-channel for highlights and linearly (luma-based) for midtones/shadows, based on a fixed gamma 2.4
               coefficient curve.

           luma
               Tone-map linearly on the luma component (CIE Y), and adjust (desaturate) the chromaticities to compensate using a
               simple constant factor. This is essentially the mode used in ITU-R BT.2446 method A.

       inverse_tonemapping
           If enabled, this filter will also attempt stretching SDR signals to fill HDR output color volumes. Disabled by default.

       tonemapping_crosstalk
           Extra tone-mapping crosstalk factor, between 0.0 and 0.3. This can help reduce issues tone-mapping certain bright
           spectral colors. Defaults to 0.04.

       tonemapping_lut_size
           Size of the tone-mapping LUT, between 2 and 1024. Defaults to 256. Note that this figure is squared when combined with
           "peak_detect".

       Dithering

       By default, libplacebo will dither whenever necessary, which includes rendering to any integer format below 16-bit
       precision. It's recommended to always leave this on, since not doing so may result in visible banding in the output, even if
       the "debanding" filter is enabled. If maximum performance is needed, use "ordered_fixed" instead of disabling dithering.

       dithering
           Dithering method to use. Accepts the following values:

           none
               Disables dithering completely. May result in visible banding.

           blue
               Dither with pseudo-blue noise. This is the default.

           ordered
               Tunable ordered dither pattern.

           ordered_fixed
               Faster ordered dither with a fixed size of 6. Texture-less.

           white
               Dither with white noise. Texture-less.

       dither_lut_size
           Dither LUT size, as log base2 between 1 and 8. Defaults to 6, corresponding to a LUT size of "64x64".

       dither_temporal
           Enables temporal dithering. Disabled by default.

       Custom shaders

       libplacebo supports a number of custom shaders based on the mpv .hook GLSL syntax. A collection of such shaders can be found
       here: <https://github.com/mpv-player/mpv/wiki/User-Scripts#user-shaders>

       A full description of the mpv shader format is beyond the scope of this section, but a summary can be found here:
       <https://mpv.io/manual/master/#options-glsl-shader>

       custom_shader_path
           Specifies a path to a custom shader file to load at runtime.

       custom_shader_bin
           Specifies a complete custom shader as a raw string.

       Debugging / performance

       All of the options in this section default off. They may be of assistance when attempting to squeeze the maximum performance
       at the cost of quality.

       skip_aa
           Disable anti-aliasing when downscaling.

       polar_cutoff
           Truncate polar (EWA) scaler kernels below this absolute magnitude, between 0.0 and 1.0.

       disable_linear
           Disable linear light scaling.

       disable_builtin
           Disable built-in GPU sampling (forces LUT).

       force_icc_lut
           Force the use of a full ICC 3DLUT for gamut mapping.

       disable_fbos
           Forcibly disable FBOs, resulting in loss of almost all functionality, but offering the maximum possible speed.

       Commands

       This filter supports almost all of the above options as commands.

       Examples

       •   Complete example for how to initialize the Vulkan device, upload frames to the GPU, perform filter conversion to
           yuv420p, and download frames back to the CPU for output. Note that in specific cases you can get around the need to
           perform format conversion by specifying the correct "format" filter option corresponding to the input frames.

                   ffmpeg -i $INPUT -init_hw_device vulkan -vf hwupload,libplacebo=format=yuv420p,hwdownload,format=yuv420p $OUTPUT

       •   Tone-map input to standard gamut BT.709 output:

                   libplacebo=colorspace=bt709:color_primaries=bt709:color_trc=bt709:range=tv

       •   Rescale input to fit into standard 1080p, with high quality scaling:

                   libplacebo=w=1920:h=1080:force_original_aspect_ratio=decrease:normalize_sar=true:upscaler=ewa_lanczos:downscaler=ewa_lanczos

       •   Convert input to standard sRGB JPEG:

                   libplacebo=format=yuv420p:colorspace=bt470bg:color_primaries=bt709:color_trc=iec61966-2-1:range=pc

       •   Use higher quality debanding settings:

                   libplacebo=deband=true:deband_iterations=3:deband_radius=8:deband_threshold=6

       •   Run this filter on the CPU, on systems with Mesa installed (and with the most expensive options disabled):

                   ffmpeg ... -init_hw_device vulkan:llvmpipe ... -vf libplacebo=upscaler=none:downscaler=none:peak_detect=false

       •   Suppress CPU-based AV1/H.274 film grain application in the decoder, in favor of doing it with this filter. Note that
           this is only a gain if the frames are either already on the GPU, or if you're using libplacebo for other purposes, since
           otherwise the VRAM roundtrip will more than offset any expected speedup.

                   ffmpeg -export_side_data +film_grain ... -vf libplacebo=apply_filmgrain=true

   libvmaf
       Calulate the VMAF (Video Multi-Method Assessment Fusion) score for a reference/distorted pair of input videos.

       The first input is the distorted video, and the second input is the reference video.

       The obtained VMAF score is printed through the logging system.

       It requires Netflix's vmaf library (libvmaf) as a pre-requisite.  After installing the library it can be enabled using:
       "./configure --enable-libvmaf".

       The filter has following options:

       model
           A `|` delimited list of vmaf models. Each model can be configured with a number of parameters.  Default value:
           "version=vmaf_v0.6.1"

       model_path
           Deprecated, use model='path=...'.

       enable_transform
           Deprecated, use model='enable_transform=true'.

       phone_model
           Deprecated, use model='enable_transform=true'.

       enable_conf_interval
           Deprecated, use model='enable_conf_interval=true'.

       feature
           A `|` delimited list of features. Each feature can be configured with a number of parameters.

       psnr
           Deprecated, use feature='name=psnr'.

       ssim
           Deprecated, use feature='name=ssim'.

       ms_ssim
           Deprecated, use feature='name=ms_ssim'.

       log_path
           Set the file path to be used to store log files.

       log_fmt
           Set the format of the log file (xml, json, csv, or sub).

       n_threads
           Set number of threads to be used when initializing libvmaf.  Default value: 0, no threads.

       n_subsample
           Set frame subsampling interval to be used.

       This filter also supports the framesync options.

       Examples

       •   In the examples below, a distorted video distorted.mpg is compared with a reference file reference.mpg.

       •   Basic usage:

                   ffmpeg -i distorted.mpg -i reference.mpg -lavfi libvmaf=log_path=output.xml -f null -

       •   Example with multiple models:

                   ffmpeg -i distorted.mpg -i reference.mpg -lavfi libvmaf='model=version=vmaf_v0.6.1\\:name=vmaf|version=vmaf_v0.6.1neg\\:name=vmaf_neg' -f null -

       •   Example with multiple addtional features:

                   ffmpeg -i distorted.mpg -i reference.mpg -lavfi libvmaf='feature=name=psnr|name=ciede' -f null -

       •   Example with options and different containers:

                   ffmpeg -i distorted.mpg -i reference.mkv -lavfi "[0:v]settb=AVTB,setpts=PTS-STARTPTS[main];[1:v]settb=AVTB,setpts=PTS-STARTPTS[ref];[main][ref]libvmaf=log_fmt=json:log_path=output.json" -f null -

   limitdiff
       Apply limited difference filter using second and optionally third video stream.

       The filter accepts the following options:

       threshold
           Set the threshold to use when allowing certain differences between video streams.  Any absolute difference value lower
           or exact than this threshold will pick pixel components from first video stream.

       elasticity
           Set the elasticity of soft thresholding when processing video streams.  This value multiplied with first one sets second
           threshold.  Any absolute difference value greater or exact than second threshold will pick pixel components from second
           video stream. For values between those two threshold linear interpolation between first and second video stream will be
           used.

       reference
           Enable the reference (third) video stream processing. By default is disabled.  If set, this video stream will be used
           for calculating absolute difference with first video stream.

       planes
           Specify which planes will be processed. Defaults to all available.

       Commands

       This filter supports the all above options as commands except option reference.

   limiter
       Limits the pixel components values to the specified range [min, max].

       The filter accepts the following options:

       min Lower bound. Defaults to the lowest allowed value for the input.

       max Upper bound. Defaults to the highest allowed value for the input.

       planes
           Specify which planes will be processed. Defaults to all available.

       Commands

       This filter supports the all above options as commands.

   loop
       Loop video frames.

       The filter accepts the following options:

       loop
           Set the number of loops. Setting this value to -1 will result in infinite loops.  Default is 0.

       size
           Set maximal size in number of frames. Default is 0.

       start
           Set first frame of loop. Default is 0.

       Examples

       •   Loop single first frame infinitely:

                   loop=loop=-1:size=1:start=0

       •   Loop single first frame 10 times:

                   loop=loop=10:size=1:start=0

       •   Loop 10 first frames 5 times:

                   loop=loop=5:size=10:start=0

   lut1d
       Apply a 1D LUT to an input video.

       The filter accepts the following options:

       file
           Set the 1D LUT file name.

           Currently supported formats:

           cube
               Iridas

           csp cineSpace

       interp
           Select interpolation mode.

           Available values are:

           nearest
               Use values from the nearest defined point.

           linear
               Interpolate values using the linear interpolation.

           cosine
               Interpolate values using the cosine interpolation.

           cubic
               Interpolate values using the cubic interpolation.

           spline
               Interpolate values using the spline interpolation.

       Commands

       This filter supports the all above options as commands.

   lut3d
       Apply a 3D LUT to an input video.

       The filter accepts the following options:

       file
           Set the 3D LUT file name.

           Currently supported formats:

           3dl AfterEffects

           cube
               Iridas

           dat DaVinci

           m3d Pandora

           csp cineSpace

       interp
           Select interpolation mode.

           Available values are:

           nearest
               Use values from the nearest defined point.

           trilinear
               Interpolate values using the 8 points defining a cube.

           tetrahedral
               Interpolate values using a tetrahedron.

           pyramid
               Interpolate values using a pyramid.

           prism
               Interpolate values using a prism.

       Commands

       This filter supports the "interp" option as commands.

   lumakey
       Turn certain luma values into transparency.

       The filter accepts the following options:

       threshold
           Set the luma which will be used as base for transparency.  Default value is 0.

       tolerance
           Set the range of luma values to be keyed out.  Default value is 0.01.

       softness
           Set the range of softness. Default value is 0.  Use this to control gradual transition from zero to full transparency.

       Commands

       This filter supports same commands as options.  The command accepts the same syntax of the corresponding option.

       If the specified expression is not valid, it is kept at its current value.

   lut, lutrgb, lutyuv
       Compute a look-up table for binding each pixel component input value to an output value, and apply it to the input video.

       lutyuv applies a lookup table to a YUV input video, lutrgb to an RGB input video.

       These filters accept the following parameters:

       c0  set first pixel component expression

       c1  set second pixel component expression

       c2  set third pixel component expression

       c3  set fourth pixel component expression, corresponds to the alpha component

       r   set red component expression

       g   set green component expression

       b   set blue component expression

       a   alpha component expression

       y   set Y/luminance component expression

       u   set U/Cb component expression

       v   set V/Cr component expression

       Each of them specifies the expression to use for computing the lookup table for the corresponding pixel component values.

       The exact component associated to each of the c* options depends on the format in input.

       The lut filter requires either YUV or RGB pixel formats in input, lutrgb requires RGB pixel formats in input, and lutyuv
       requires YUV.

       The expressions can contain the following constants and functions:

       w
       h   The input width and height.

       val The input value for the pixel component.

       clipval
           The input value, clipped to the minval-maxval range.

       maxval
           The maximum value for the pixel component.

       minval
           The minimum value for the pixel component.

       negval
           The negated value for the pixel component value, clipped to the minval-maxval range; it corresponds to the expression
           "maxval-clipval+minval".

       clip(val)
           The computed value in val, clipped to the minval-maxval range.

       gammaval(gamma)
           The computed gamma correction value of the pixel component value, clipped to the minval-maxval range. It corresponds to
           the expression "pow((clipval-minval)/(maxval-minval)\,gamma)*(maxval-minval)+minval"

       All expressions default to "clipval".

       Commands

       This filter supports same commands as options.

       Examples

       •   Negate input video:

                   lutrgb="r=maxval+minval-val:g=maxval+minval-val:b=maxval+minval-val"
                   lutyuv="y=maxval+minval-val:u=maxval+minval-val:v=maxval+minval-val"

           The above is the same as:

                   lutrgb="r=negval:g=negval:b=negval"
                   lutyuv="y=negval:u=negval:v=negval"

       •   Negate luminance:

                   lutyuv=y=negval

       •   Remove chroma components, turning the video into a graytone image:

                   lutyuv="u=128:v=128"

       •   Apply a luma burning effect:

                   lutyuv="y=2*val"

       •   Remove green and blue components:

                   lutrgb="g=0:b=0"

       •   Set a constant alpha channel value on input:

                   format=rgba,lutrgb=a="maxval-minval/2"

       •   Correct luminance gamma by a factor of 0.5:

                   lutyuv=y=gammaval(0.5)

       •   Discard least significant bits of luma:

                   lutyuv=y='bitand(val, 128+64+32)'

       •   Technicolor like effect:

                   lutyuv=u='(val-maxval/2)*2+maxval/2':v='(val-maxval/2)*2+maxval/2'

   lut2, tlut2
       The "lut2" filter takes two input streams and outputs one stream.

       The "tlut2" (time lut2) filter takes two consecutive frames from one single stream.

       This filter accepts the following parameters:

       c0  set first pixel component expression

       c1  set second pixel component expression

       c2  set third pixel component expression

       c3  set fourth pixel component expression, corresponds to the alpha component

       d   set output bit depth, only available for "lut2" filter. By default is 0, which means bit depth is automatically picked
           from first input format.

       The "lut2" filter also supports the framesync options.

       Each of them specifies the expression to use for computing the lookup table for the corresponding pixel component values.

       The exact component associated to each of the c* options depends on the format in inputs.

       The expressions can contain the following constants:

       w
       h   The input width and height.

       x   The first input value for the pixel component.

       y   The second input value for the pixel component.

       bdx The first input video bit depth.

       bdy The second input video bit depth.

       All expressions default to "x".

       Commands

       This filter supports the all above options as commands except option "d".

       Examples

       •   Highlight differences between two RGB video streams:

                   lut2='ifnot(x-y,0,pow(2,bdx)-1):ifnot(x-y,0,pow(2,bdx)-1):ifnot(x-y,0,pow(2,bdx)-1)'

       •   Highlight differences between two YUV video streams:

                   lut2='ifnot(x-y,0,pow(2,bdx)-1):ifnot(x-y,pow(2,bdx-1),pow(2,bdx)-1):ifnot(x-y,pow(2,bdx-1),pow(2,bdx)-1)'

       •   Show max difference between two video streams:

                   lut2='if(lt(x,y),0,if(gt(x,y),pow(2,bdx)-1,pow(2,bdx-1))):if(lt(x,y),0,if(gt(x,y),pow(2,bdx)-1,pow(2,bdx-1))):if(lt(x,y),0,if(gt(x,y),pow(2,bdx)-1,pow(2,bdx-1)))'

   maskedclamp
       Clamp the first input stream with the second input and third input stream.

       Returns the value of first stream to be between second input stream - "undershoot" and third input stream + "overshoot".

       This filter accepts the following options:

       undershoot
           Default value is 0.

       overshoot
           Default value is 0.

       planes
           Set which planes will be processed as bitmap, unprocessed planes will be copied from first stream.  By default value
           0xf, all planes will be processed.

       Commands

       This filter supports the all above options as commands.

   maskedmax
       Merge the second and third input stream into output stream using absolute differences between second input stream and first
       input stream and absolute difference between third input stream and first input stream. The picked value will be from second
       input stream if second absolute difference is greater than first one or from third input stream otherwise.

       This filter accepts the following options:

       planes
           Set which planes will be processed as bitmap, unprocessed planes will be copied from first stream.  By default value
           0xf, all planes will be processed.

       Commands

       This filter supports the all above options as commands.

   maskedmerge
       Merge the first input stream with the second input stream using per pixel weights in the third input stream.

       A value of 0 in the third stream pixel component means that pixel component from first stream is returned unchanged, while
       maximum value (eg. 255 for 8-bit videos) means that pixel component from second stream is returned unchanged. Intermediate
       values define the amount of merging between both input stream's pixel components.

       This filter accepts the following options:

       planes
           Set which planes will be processed as bitmap, unprocessed planes will be copied from first stream.  By default value
           0xf, all planes will be processed.

       Commands

       This filter supports the all above options as commands.

   maskedmin
       Merge the second and third input stream into output stream using absolute differences between second input stream and first
       input stream and absolute difference between third input stream and first input stream. The picked value will be from second
       input stream if second absolute difference is less than first one or from third input stream otherwise.

       This filter accepts the following options:

       planes
           Set which planes will be processed as bitmap, unprocessed planes will be copied from first stream.  By default value
           0xf, all planes will be processed.

       Commands

       This filter supports the all above options as commands.

   maskedthreshold
       Pick pixels comparing absolute difference of two video streams with fixed threshold.

       If absolute difference between pixel component of first and second video stream is equal or lower than user supplied
       threshold than pixel component from first video stream is picked, otherwise pixel component from second video stream is
       picked.

       This filter accepts the following options:

       threshold
           Set threshold used when picking pixels from absolute difference from two input video streams.

       planes
           Set which planes will be processed as bitmap, unprocessed planes will be copied from second stream.  By default value
           0xf, all planes will be processed.

       Commands

       This filter supports the all above options as commands.

   maskfun
       Create mask from input video.

       For example it is useful to create motion masks after "tblend" filter.

       This filter accepts the following options:

       low Set low threshold. Any pixel component lower or exact than this value will be set to 0.

       high
           Set high threshold. Any pixel component higher than this value will be set to max value allowed for current pixel
           format.

       planes
           Set planes to filter, by default all available planes are filtered.

       fill
           Fill all frame pixels with this value.

       sum Set max average pixel value for frame. If sum of all pixel components is higher that this average, output frame will be
           completely filled with value set by fill option.  Typically useful for scene changes when used in combination with
           "tblend" filter.

       Commands

       This filter supports the all above options as commands.

   mcdeint
       Apply motion-compensation deinterlacing.

       It needs one field per frame as input and must thus be used together with yadif=1/3 or equivalent.

       This filter is only available in ffmpeg version 4.4 or earlier.

       This filter accepts the following options:

       mode
           Set the deinterlacing mode.

           It accepts one of the following values:

           fast
           medium
           slow
               use iterative motion estimation

           extra_slow
               like slow, but use multiple reference frames.

           Default value is fast.

       parity
           Set the picture field parity assumed for the input video. It must be one of the following values:

           0, tff
               assume top field first

           1, bff
               assume bottom field first

           Default value is bff.

       qp  Set per-block quantization parameter (QP) used by the internal encoder.

           Higher values should result in a smoother motion vector field but less optimal individual vectors. Default value is 1.

   median
       Pick median pixel from certain rectangle defined by radius.

       This filter accepts the following options:

       radius
           Set horizontal radius size. Default value is 1.  Allowed range is integer from 1 to 127.

       planes
           Set which planes to process. Default is 15, which is all available planes.

       radiusV
           Set vertical radius size. Default value is 0.  Allowed range is integer from 0 to 127.  If it is 0, value will be picked
           from horizontal "radius" option.

       percentile
           Set median percentile. Default value is 0.5.  Default value of 0.5 will pick always median values, while 0 will pick
           minimum values, and 1 maximum values.

       Commands

       This filter supports same commands as options.  The command accepts the same syntax of the corresponding option.

       If the specified expression is not valid, it is kept at its current value.

   mergeplanes
       Merge color channel components from several video streams.

       The filter accepts up to 4 input streams, and merge selected input planes to the output video.

       This filter accepts the following options:

       mapping
           Set input to output plane mapping. Default is 0.

           The mappings is specified as a bitmap. It should be specified as a hexadecimal number in the form 0xAa[Bb[Cc[Dd]]]. 'Aa'
           describes the mapping for the first plane of the output stream. 'A' sets the number of the input stream to use (from 0
           to 3), and 'a' the plane number of the corresponding input to use (from 0 to 3). The rest of the mappings is similar,
           'Bb' describes the mapping for the output stream second plane, 'Cc' describes the mapping for the output stream third
           plane and 'Dd' describes the mapping for the output stream fourth plane.

       format
           Set output pixel format. Default is "yuva444p".

       map0s
       map1s
       map2s
       map3s
           Set input to output stream mapping for output Nth plane. Default is 0.

       map0p
       map1p
       map2p
       map3p
           Set input to output plane mapping for output Nth plane. Default is 0.

       Examples

       •   Merge three gray video streams of same width and height into single video stream:

                   [a0][a1][a2]mergeplanes=0x001020:yuv444p

       •   Merge 1st yuv444p stream and 2nd gray video stream into yuva444p video stream:

                   [a0][a1]mergeplanes=0x00010210:yuva444p

       •   Swap Y and A plane in yuva444p stream:

                   format=yuva444p,mergeplanes=0x03010200:yuva444p

       •   Swap U and V plane in yuv420p stream:

                   format=yuv420p,mergeplanes=0x000201:yuv420p

       •   Cast a rgb24 clip to yuv444p:

                   format=rgb24,mergeplanes=0x000102:yuv444p

   mestimate
       Estimate and export motion vectors using block matching algorithms.  Motion vectors are stored in frame side data to be used
       by other filters.

       This filter accepts the following options:

       method
           Specify the motion estimation method. Accepts one of the following values:

           esa Exhaustive search algorithm.

           tss Three step search algorithm.

           tdls
               Two dimensional logarithmic search algorithm.

           ntss
               New three step search algorithm.

           fss Four step search algorithm.

           ds  Diamond search algorithm.

           hexbs
               Hexagon-based search algorithm.

           epzs
               Enhanced predictive zonal search algorithm.

           umh Uneven multi-hexagon search algorithm.

           Default value is esa.

       mb_size
           Macroblock size. Default 16.

       search_param
           Search parameter. Default 7.

   midequalizer
       Apply Midway Image Equalization effect using two video streams.

       Midway Image Equalization adjusts a pair of images to have the same histogram, while maintaining their dynamics as much as
       possible. It's useful for e.g. matching exposures from a pair of stereo cameras.

       This filter has two inputs and one output, which must be of same pixel format, but may be of different sizes. The output of
       filter is first input adjusted with midway histogram of both inputs.

       This filter accepts the following option:

       planes
           Set which planes to process. Default is 15, which is all available planes.

   minterpolate
       Convert the video to specified frame rate using motion interpolation.

       This filter accepts the following options:

       fps Specify the output frame rate. This can be rational e.g. "60000/1001". Frames are dropped if fps is lower than source
           fps. Default 60.

       mi_mode
           Motion interpolation mode. Following values are accepted:

           dup Duplicate previous or next frame for interpolating new ones.

           blend
               Blend source frames. Interpolated frame is mean of previous and next frames.

           mci Motion compensated interpolation. Following options are effective when this mode is selected:

               mc_mode
                   Motion compensation mode. Following values are accepted:

                   obmc
                       Overlapped block motion compensation.

                   aobmc
                       Adaptive overlapped block motion compensation. Window weighting coefficients are controlled adaptively
                       according to the reliabilities of the neighboring motion vectors to reduce oversmoothing.

                   Default mode is obmc.

               me_mode
                   Motion estimation mode. Following values are accepted:

                   bidir
                       Bidirectional motion estimation. Motion vectors are estimated for each source frame in both forward and
                       backward directions.

                   bilat
                       Bilateral motion estimation. Motion vectors are estimated directly for interpolated frame.

                   Default mode is bilat.

               me  The algorithm to be used for motion estimation. Following values are accepted:

                   esa Exhaustive search algorithm.

                   tss Three step search algorithm.

                   tdls
                       Two dimensional logarithmic search algorithm.

                   ntss
                       New three step search algorithm.

                   fss Four step search algorithm.

                   ds  Diamond search algorithm.

                   hexbs
                       Hexagon-based search algorithm.

                   epzs
                       Enhanced predictive zonal search algorithm.

                   umh Uneven multi-hexagon search algorithm.

                   Default algorithm is epzs.

               mb_size
                   Macroblock size. Default 16.

               search_param
                   Motion estimation search parameter. Default 32.

               vsbmc
                   Enable variable-size block motion compensation. Motion estimation is applied with smaller block sizes at object
                   boundaries in order to make the them less blur. Default is 0 (disabled).

       scd Scene change detection method. Scene change leads motion vectors to be in random direction. Scene change detection
           replace interpolated frames by duplicate ones. May not be needed for other modes. Following values are accepted:

           none
               Disable scene change detection.

           fdiff
               Frame difference. Corresponding pixel values are compared and if it satisfies scd_threshold scene change is
               detected.

           Default method is fdiff.

       scd_threshold
           Scene change detection threshold. Default is 10..

   mix
       Mix several video input streams into one video stream.

       A description of the accepted options follows.

       inputs
           The number of inputs. If unspecified, it defaults to 2.

       weights
           Specify weight of each input video stream as sequence.  Each weight is separated by space. If number of weights is
           smaller than number of frames last specified weight will be used for all remaining unset weights.

       scale
           Specify scale, if it is set it will be multiplied with sum of each weight multiplied with pixel values to give final
           destination pixel value. By default scale is auto scaled to sum of weights.

       planes
           Set which planes to filter. Default is all. Allowed range is from 0 to 15.

       duration
           Specify how end of stream is determined.

           longest
               The duration of the longest input. (default)

           shortest
               The duration of the shortest input.

           first
               The duration of the first input.

       Commands

       This filter supports the following commands:

       weights
       scale
       planes
           Syntax is same as option with same name.

   monochrome
       Convert video to gray using custom color filter.

       A description of the accepted options follows.

       cb  Set the chroma blue spot. Allowed range is from -1 to 1.  Default value is 0.

       cr  Set the chroma red spot. Allowed range is from -1 to 1.  Default value is 0.

       size
           Set the color filter size. Allowed range is from .1 to 10.  Default value is 1.

       high
           Set the highlights strength. Allowed range is from 0 to 1.  Default value is 0.

       Commands

       This filter supports the all above options as commands.

   morpho
       This filter allows to apply main morphological grayscale transforms, erode and dilate with arbitrary structures set in
       second input stream.

       Unlike naive implementation and much slower performance in erosion and dilation filters, when speed is critical "morpho"
       filter should be used instead.

       A description of accepted options follows,

       mode
           Set morphological transform to apply, can be:

           erode
           dilate
           open
           close
           gradient
           tophat
           blackhat

           Default is "erode".

       planes
           Set planes to filter, by default all planes except alpha are filtered.

       structure
           Set which structure video frames will be processed from second input stream, can be first or all. Default is all.

       The "morpho" filter also supports the framesync options.

       Commands

       This filter supports same commands as options.

   mpdecimate
       Drop frames that do not differ greatly from the previous frame in order to reduce frame rate.

       The main use of this filter is for very-low-bitrate encoding (e.g. streaming over dialup modem), but it could in theory be
       used for fixing movies that were inverse-telecined incorrectly.

       A description of the accepted options follows.

       max Set the maximum number of consecutive frames which can be dropped (if positive), or the minimum interval between dropped
           frames (if negative). If the value is 0, the frame is dropped disregarding the number of previous sequentially dropped
           frames.

           Default value is 0.

       hi
       lo
       frac
           Set the dropping threshold values.

           Values for hi and lo are for 8x8 pixel blocks and represent actual pixel value differences, so a threshold of 64
           corresponds to 1 unit of difference for each pixel, or the same spread out differently over the block.

           A frame is a candidate for dropping if no 8x8 blocks differ by more than a threshold of hi, and if no more than frac
           blocks (1 meaning the whole image) differ by more than a threshold of lo.

           Default value for hi is 64*12, default value for lo is 64*5, and default value for frac is 0.33.

   msad
       Obtain the MSAD (Mean Sum of Absolute Differences) between two input videos.

       This filter takes two input videos.

       Both input videos must have the same resolution and pixel format for this filter to work correctly. Also it assumes that
       both inputs have the same number of frames, which are compared one by one.

       The obtained per component, average, min and max MSAD is printed through the logging system.

       The filter stores the calculated MSAD of each frame in frame metadata.

       In the below example the input file main.mpg being processed is compared with the reference file ref.mpg.

               ffmpeg -i main.mpg -i ref.mpg -lavfi msad -f null -

   multiply
       Multiply first video stream pixels values with second video stream pixels values.

       The filter accepts the following options:

       scale
           Set the scale applied to second video stream. By default is 1.  Allowed range is from 0 to 9.

       offset
           Set the offset applied to second video stream. By default is 0.5.  Allowed range is from "-1" to 1.

       planes
           Specify planes from input video stream that will be processed.  By default all planes are processed.

       Commands

       This filter supports same commands as options.

   negate
       Negate (invert) the input video.

       It accepts the following option:

       components
           Set components to negate.

           Available values for components are:

           y
           u
           v
           a
           r
           g
           b
       negate_alpha
           With value 1, it negates the alpha component, if present. Default value is 0.

       Commands

       This filter supports same commands as options.

   nlmeans
       Denoise frames using Non-Local Means algorithm.

       Each pixel is adjusted by looking for other pixels with similar contexts. This context similarity is defined by comparing
       their surrounding patches of size pxp. Patches are searched in an area of rxr around the pixel.

       Note that the research area defines centers for patches, which means some patches will be made of pixels outside that
       research area.

       The filter accepts the following options.

       s   Set denoising strength. Default is 1.0. Must be in range [1.0, 30.0].

       p   Set patch size. Default is 7. Must be odd number in range [0, 99].

       pc  Same as p but for chroma planes.

           The default value is 0 and means automatic.

       r   Set research size. Default is 15. Must be odd number in range [0, 99].

       rc  Same as r but for chroma planes.

           The default value is 0 and means automatic.

   nnedi
       Deinterlace video using neural network edge directed interpolation.

       This filter accepts the following options:

       weights
           Mandatory option, without binary file filter can not work.  Currently file can be found here:
           https://github.com/dubhater/vapoursynth-nnedi3/blob/master/src/nnedi3_weights.bin

       deint
           Set which frames to deinterlace, by default it is "all".  Can be "all" or "interlaced".

       field
           Set mode of operation.

           Can be one of the following:

           af  Use frame flags, both fields.

           a   Use frame flags, single field.

           t   Use top field only.

           b   Use bottom field only.

           tf  Use both fields, top first.

           bf  Use both fields, bottom first.

       planes
           Set which planes to process, by default filter process all frames.

       nsize
           Set size of local neighborhood around each pixel, used by the predictor neural network.

           Can be one of the following:

           s8x6
           s16x6
           s32x6
           s48x6
           s8x4
           s16x4
           s32x4
       nns Set the number of neurons in predictor neural network.  Can be one of the following:

           n16
           n32
           n64
           n128
           n256
       qual
           Controls the number of different neural network predictions that are blended together to compute the final output value.
           Can be "fast", default or "slow".

       etype
           Set which set of weights to use in the predictor.  Can be one of the following:

           a, abs
               weights trained to minimize absolute error

           s, mse
               weights trained to minimize squared error

       pscrn
           Controls whether or not the prescreener neural network is used to decide which pixels should be processed by the
           predictor neural network and which can be handled by simple cubic interpolation.  The prescreener is trained to know
           whether cubic interpolation will be sufficient for a pixel or whether it should be predicted by the predictor nn.  The
           computational complexity of the prescreener nn is much less than that of the predictor nn. Since most pixels can be
           handled by cubic interpolation, using the prescreener generally results in much faster processing.  The prescreener is
           pretty accurate, so the difference between using it and not using it is almost always unnoticeable.

           Can be one of the following:

           none
           original
           new
           new2
           new3

           Default is "new".

       Commands

       This filter supports same commands as options, excluding weights option.

   noformat
       Force libavfilter not to use any of the specified pixel formats for the input to the next filter.

       It accepts the following parameters:

       pix_fmts
           A '|'-separated list of pixel format names, such as pix_fmts=yuv420p|monow|rgb24".

       Examples

       •   Force libavfilter to use a format different from yuv420p for the input to the vflip filter:

                   noformat=pix_fmts=yuv420p,vflip

       •   Convert the input video to any of the formats not contained in the list:

                   noformat=yuv420p|yuv444p|yuv410p

   noise
       Add noise on video input frame.

       The filter accepts the following options:

       all_seed
       c0_seed
       c1_seed
       c2_seed
       c3_seed
           Set noise seed for specific pixel component or all pixel components in case of all_seed. Default value is 123457.

       all_strength, alls
       c0_strength, c0s
       c1_strength, c1s
       c2_strength, c2s
       c3_strength, c3s
           Set noise strength for specific pixel component or all pixel components in case all_strength. Default value is 0.
           Allowed range is [0, 100].

       all_flags, allf
       c0_flags, c0f
       c1_flags, c1f
       c2_flags, c2f
       c3_flags, c3f
           Set pixel component flags or set flags for all components if all_flags.  Available values for component flags are:

           a   averaged temporal noise (smoother)

           p   mix random noise with a (semi)regular pattern

           t   temporal noise (noise pattern changes between frames)

           u   uniform noise (gaussian otherwise)

       Examples

       Add temporal and uniform noise to input video:

               noise=alls=20:allf=t+u

   normalize
       Normalize RGB video (aka histogram stretching, contrast stretching).  See:
       https://en.wikipedia.org/wiki/Normalization_(image_processing)

       For each channel of each frame, the filter computes the input range and maps it linearly to the user-specified output range.
       The output range defaults to the full dynamic range from pure black to pure white.

       Temporal smoothing can be used on the input range to reduce flickering (rapid changes in brightness) caused when small dark
       or bright objects enter or leave the scene. This is similar to the auto-exposure (automatic gain control) on a video camera,
       and, like a video camera, it may cause a period of over- or under-exposure of the video.

       The R,G,B channels can be normalized independently, which may cause some color shifting, or linked together as a single
       channel, which prevents color shifting. Linked normalization preserves hue. Independent normalization does not, so it can be
       used to remove some color casts. Independent and linked normalization can be combined in any ratio.

       The normalize filter accepts the following options:

       blackpt
       whitept
           Colors which define the output range. The minimum input value is mapped to the blackpt. The maximum input value is
           mapped to the whitept.  The defaults are black and white respectively. Specifying white for blackpt and black for
           whitept will give color-inverted, normalized video. Shades of grey can be used to reduce the dynamic range (contrast).
           Specifying saturated colors here can create some interesting effects.

       smoothing
           The number of previous frames to use for temporal smoothing. The input range of each channel is smoothed using a rolling
           average over the current frame and the smoothing previous frames. The default is 0 (no temporal smoothing).

       independence
           Controls the ratio of independent (color shifting) channel normalization to linked (color preserving) normalization. 0.0
           is fully linked, 1.0 is fully independent. Defaults to 1.0 (fully independent).

       strength
           Overall strength of the filter. 1.0 is full strength. 0.0 is a rather expensive no-op. Defaults to 1.0 (full strength).

       Commands

       This filter supports same commands as options, excluding smoothing option.  The command accepts the same syntax of the
       corresponding option.

       If the specified expression is not valid, it is kept at its current value.

       Examples

       Stretch video contrast to use the full dynamic range, with no temporal smoothing; may flicker depending on the source
       content:

               normalize=blackpt=black:whitept=white:smoothing=0

       As above, but with 50 frames of temporal smoothing; flicker should be reduced, depending on the source content:

               normalize=blackpt=black:whitept=white:smoothing=50

       As above, but with hue-preserving linked channel normalization:

               normalize=blackpt=black:whitept=white:smoothing=50:independence=0

       As above, but with half strength:

               normalize=blackpt=black:whitept=white:smoothing=50:independence=0:strength=0.5

       Map the darkest input color to red, the brightest input color to cyan:

               normalize=blackpt=red:whitept=cyan

   null
       Pass the video source unchanged to the output.

   ocr
       Optical Character Recognition

       This filter uses Tesseract for optical character recognition. To enable compilation of this filter, you need to configure
       FFmpeg with "--enable-libtesseract".

       It accepts the following options:

       datapath
           Set datapath to tesseract data. Default is to use whatever was set at installation.

       language
           Set language, default is "eng".

       whitelist
           Set character whitelist.

       blacklist
           Set character blacklist.

       The filter exports recognized text as the frame metadata "lavfi.ocr.text".  The filter exports confidence of recognized
       words as the frame metadata "lavfi.ocr.confidence".

   ocv
       Apply a video transform using libopencv.

       To enable this filter, install the libopencv library and headers and configure FFmpeg with "--enable-libopencv".

       It accepts the following parameters:

       filter_name
           The name of the libopencv filter to apply.

       filter_params
           The parameters to pass to the libopencv filter. If not specified, the default values are assumed.

       Refer to the official libopencv documentation for more precise information:
       <http://docs.opencv.org/master/modules/imgproc/doc/filtering.html>

       Several libopencv filters are supported; see the following subsections.

       dilate

       Dilate an image by using a specific structuring element.  It corresponds to the libopencv function "cvDilate".

       It accepts the parameters: struct_el|nb_iterations.

       struct_el represents a structuring element, and has the syntax: colsxrows+anchor_xxanchor_y/shape

       cols and rows represent the number of columns and rows of the structuring element, anchor_x and anchor_y the anchor point,
       and shape the shape for the structuring element. shape must be "rect", "cross", "ellipse", or "custom".

       If the value for shape is "custom", it must be followed by a string of the form "=filename". The file with name filename is
       assumed to represent a binary image, with each printable character corresponding to a bright pixel. When a custom shape is
       used, cols and rows are ignored, the number or columns and rows of the read file are assumed instead.

       The default value for struct_el is "3x3+0x0/rect".

       nb_iterations specifies the number of times the transform is applied to the image, and defaults to 1.

       Some examples:

               # Use the default values
               ocv=dilate

               # Dilate using a structuring element with a 5x5 cross, iterating two times
               ocv=filter_name=dilate:filter_params=5x5+2x2/cross|2

               # Read the shape from the file diamond.shape, iterating two times.
               # The file diamond.shape may contain a pattern of characters like this
               #   *
               #  ***
               # *****
               #  ***
               #   *
               # The specified columns and rows are ignored
               # but the anchor point coordinates are not
               ocv=dilate:0x0+2x2/custom=diamond.shape|2

       erode

       Erode an image by using a specific structuring element.  It corresponds to the libopencv function "cvErode".

       It accepts the parameters: struct_el:nb_iterations, with the same syntax and semantics as the dilate filter.

       smooth

       Smooth the input video.

       The filter takes the following parameters: type|param1|param2|param3|param4.

       type is the type of smooth filter to apply, and must be one of the following values: "blur", "blur_no_scale", "median",
       "gaussian", or "bilateral". The default value is "gaussian".

       The meaning of param1, param2, param3, and param4 depends on the smooth type. param1 and param2 accept integer positive
       values or 0. param3 and param4 accept floating point values.

       The default value for param1 is 3. The default value for the other parameters is 0.

       These parameters correspond to the parameters assigned to the libopencv function "cvSmooth".

   oscilloscope
       2D Video Oscilloscope.

       Useful to measure spatial impulse, step responses, chroma delays, etc.

       It accepts the following parameters:

       x   Set scope center x position.

       y   Set scope center y position.

       s   Set scope size, relative to frame diagonal.

       t   Set scope tilt/rotation.

       o   Set trace opacity.

       tx  Set trace center x position.

       ty  Set trace center y position.

       tw  Set trace width, relative to width of frame.

       th  Set trace height, relative to height of frame.

       c   Set which components to trace. By default it traces first three components.

       g   Draw trace grid. By default is enabled.

       st  Draw some statistics. By default is enabled.

       sc  Draw scope. By default is enabled.

       Commands

       This filter supports same commands as options.  The command accepts the same syntax of the corresponding option.

       If the specified expression is not valid, it is kept at its current value.

       Examples

       •   Inspect full first row of video frame.

                   oscilloscope=x=0.5:y=0:s=1

       •   Inspect full last row of video frame.

                   oscilloscope=x=0.5:y=1:s=1

       •   Inspect full 5th line of video frame of height 1080.

                   oscilloscope=x=0.5:y=5/1080:s=1

       •   Inspect full last column of video frame.

                   oscilloscope=x=1:y=0.5:s=1:t=1

   overlay
       Overlay one video on top of another.

       It takes two inputs and has one output. The first input is the "main" video on which the second input is overlaid.

       It accepts the following parameters:

       A description of the accepted options follows.

       x
       y   Set the expression for the x and y coordinates of the overlaid video on the main video. Default value is "0" for both
           expressions. In case the expression is invalid, it is set to a huge value (meaning that the overlay will not be
           displayed within the output visible area).

       eof_action
           See framesync.

       eval
           Set when the expressions for x, and y are evaluated.

           It accepts the following values:

           init
               only evaluate expressions once during the filter initialization or when a command is processed

           frame
               evaluate expressions for each incoming frame

           Default value is frame.

       shortest
           See framesync.

       format
           Set the format for the output video.

           It accepts the following values:

           yuv420
               force YUV420 output

           yuv420p10
               force YUV420p10 output

           yuv422
               force YUV422 output

           yuv422p10
               force YUV422p10 output

           yuv444
               force YUV444 output

           rgb force packed RGB output

           gbrp
               force planar RGB output

           auto
               automatically pick format

           Default value is yuv420.

       repeatlast
           See framesync.

       alpha
           Set format of alpha of the overlaid video, it can be straight or premultiplied. Default is straight.

       The x, and y expressions can contain the following parameters.

       main_w, W
       main_h, H
           The main input width and height.

       overlay_w, w
       overlay_h, h
           The overlay input width and height.

       x
       y   The computed values for x and y. They are evaluated for each new frame.

       hsub
       vsub
           horizontal and vertical chroma subsample values of the output format. For example for the pixel format "yuv422p" hsub is
           2 and vsub is 1.

       n   the number of input frame, starting from 0

       pos the position in the file of the input frame, NAN if unknown

       t   The timestamp, expressed in seconds. It's NAN if the input timestamp is unknown.

       This filter also supports the framesync options.

       Note that the n, pos, t variables are available only when evaluation is done per frame, and will evaluate to NAN when eval
       is set to init.

       Be aware that frames are taken from each input video in timestamp order, hence, if their initial timestamps differ, it is a
       good idea to pass the two inputs through a setpts=PTS-STARTPTS filter to have them begin in the same zero timestamp, as the
       example for the movie filter does.

       You can chain together more overlays but you should test the efficiency of such approach.

       Commands

       This filter supports the following commands:

       x
       y   Modify the x and y of the overlay input.  The command accepts the same syntax of the corresponding option.

           If the specified expression is not valid, it is kept at its current value.

       Examples

       •   Draw the overlay at 10 pixels from the bottom right corner of the main video:

                   overlay=main_w-overlay_w-10:main_h-overlay_h-10

           Using named options the example above becomes:

                   overlay=x=main_w-overlay_w-10:y=main_h-overlay_h-10

       •   Insert a transparent PNG logo in the bottom left corner of the input, using the ffmpeg tool with the "-filter_complex"
           option:

                   ffmpeg -i input -i logo -filter_complex 'overlay=10:main_h-overlay_h-10' output

       •   Insert 2 different transparent PNG logos (second logo on bottom right corner) using the ffmpeg tool:

                   ffmpeg -i input -i logo1 -i logo2 -filter_complex 'overlay=x=10:y=H-h-10,overlay=x=W-w-10:y=H-h-10' output

       •   Add a transparent color layer on top of the main video; "WxH" must specify the size of the main input to the overlay
           filter:

                   color=color=red@.3:size=WxH [over]; [in][over] overlay [out]

       •   Play an original video and a filtered version (here with the deshake filter) side by side using the ffplay tool:

                   ffplay input.avi -vf 'split[a][b]; [a]pad=iw*2:ih[src]; [b]deshake[filt]; [src][filt]overlay=w'

           The above command is the same as:

                   ffplay input.avi -vf 'split[b], pad=iw*2[src], [b]deshake, [src]overlay=w'

       •   Make a sliding overlay appearing from the left to the right top part of the screen starting since time 2:

                   overlay=x='if(gte(t,2), -w+(t-2)*20, NAN)':y=0

       •   Compose output by putting two input videos side to side:

                   ffmpeg -i left.avi -i right.avi -filter_complex "
                   nullsrc=size=200x100 [background];
                   [0:v] setpts=PTS-STARTPTS, scale=100x100 [left];
                   [1:v] setpts=PTS-STARTPTS, scale=100x100 [right];
                   [background][left]       overlay=shortest=1       [background+left];
                   [background+left][right] overlay=shortest=1:x=100 [left+right]
                   "

       •   Mask 10-20 seconds of a video by applying the delogo filter to a section

                   ffmpeg -i test.avi -codec:v:0 wmv2 -ar 11025 -b:v 9000k
                   -vf '[in]split[split_main][split_delogo];[split_delogo]trim=start=360:end=371,delogo=0:0:640:480[delogoed];[split_main][delogoed]overlay=eof_action=pass[out]'
                   masked.avi

       •   Chain several overlays in cascade:

                   nullsrc=s=200x200 [bg];
                   testsrc=s=100x100, split=4 [in0][in1][in2][in3];
                   [in0] lutrgb=r=0, [bg]   overlay=0:0     [mid0];
                   [in1] lutrgb=g=0, [mid0] overlay=100:0   [mid1];
                   [in2] lutrgb=b=0, [mid1] overlay=0:100   [mid2];
                   [in3] null,       [mid2] overlay=100:100 [out0]

   overlay_cuda
       Overlay one video on top of another.

       This is the CUDA variant of the overlay filter.  It only accepts CUDA frames. The underlying input pixel formats have to
       match.

       It takes two inputs and has one output. The first input is the "main" video on which the second input is overlaid.

       It accepts the following parameters:

       x
       y   Set expressions for the x and y coordinates of the overlaid video on the main video.

           They can contain the following parameters:

           main_w, W
           main_h, H
               The main input width and height.

           overlay_w, w
           overlay_h, h
               The overlay input width and height.

           x
           y   The computed values for x and y. They are evaluated for each new frame.

           n   The ordinal index of the main input frame, starting from 0.

           pos The byte offset position in the file of the main input frame, NAN if unknown.

           t   The timestamp of the main input frame, expressed in seconds, NAN if unknown.

           Default value is "0" for both expressions.

       eval
           Set when the expressions for x and y are evaluated.

           It accepts the following values:

           init
               Evaluate expressions once during filter initialization or when a command is processed.

           frame
               Evaluate expressions for each incoming frame

           Default value is frame.

       eof_action
           See framesync.

       shortest
           See framesync.

       repeatlast
           See framesync.

       This filter also supports the framesync options.

   owdenoise
       Apply Overcomplete Wavelet denoiser.

       The filter accepts the following options:

       depth
           Set depth.

           Larger depth values will denoise lower frequency components more, but slow down filtering.

           Must be an int in the range 8-16, default is 8.

       luma_strength, ls
           Set luma strength.

           Must be a double value in the range 0-1000, default is 1.0.

       chroma_strength, cs
           Set chroma strength.

           Must be a double value in the range 0-1000, default is 1.0.

   pad
       Add paddings to the input image, and place the original input at the provided x, y coordinates.

       It accepts the following parameters:

       width, w
       height, h
           Specify an expression for the size of the output image with the paddings added. If the value for width or height is 0,
           the corresponding input size is used for the output.

           The width expression can reference the value set by the height expression, and vice versa.

           The default value of width and height is 0.

       x
       y   Specify the offsets to place the input image at within the padded area, with respect to the top/left border of the
           output image.

           The x expression can reference the value set by the y expression, and vice versa.

           The default value of x and y is 0.

           If x or y evaluate to a negative number, they'll be changed so the input image is centered on the padded area.

       color
           Specify the color of the padded area. For the syntax of this option, check the "Color" section in the ffmpeg-utils
           manual.

           The default value of color is "black".

       eval
           Specify when to evaluate  width, height, x and y expression.

           It accepts the following values:

           init
               Only evaluate expressions once during the filter initialization or when a command is processed.

           frame
               Evaluate expressions for each incoming frame.

           Default value is init.

       aspect
           Pad to aspect instead to a resolution.

       The value for the width, height, x, and y options are expressions containing the following constants:

       in_w
       in_h
           The input video width and height.

       iw
       ih  These are the same as in_w and in_h.

       out_w
       out_h
           The output width and height (the size of the padded area), as specified by the width and height expressions.

       ow
       oh  These are the same as out_w and out_h.

       x
       y   The x and y offsets as specified by the x and y expressions, or NAN if not yet specified.

       a   same as iw / ih

       sar input sample aspect ratio

       dar input display aspect ratio, it is the same as (iw / ih) * sar

       hsub
       vsub
           The horizontal and vertical chroma subsample values. For example for the pixel format "yuv422p" hsub is 2 and vsub is 1.

       Examples

       •   Add paddings with the color "violet" to the input video. The output video size is 640x480, and the top-left corner of
           the input video is placed at column 0, row 40

                   pad=640:480:0:40:violet

           The example above is equivalent to the following command:

                   pad=width=640:height=480:x=0:y=40:color=violet

       •   Pad the input to get an output with dimensions increased by 3/2, and put the input video at the center of the padded
           area:

                   pad="3/2*iw:3/2*ih:(ow-iw)/2:(oh-ih)/2"

       •   Pad the input to get a squared output with size equal to the maximum value between the input width and height, and put
           the input video at the center of the padded area:

                   pad="max(iw\,ih):ow:(ow-iw)/2:(oh-ih)/2"

       •   Pad the input to get a final w/h ratio of 16:9:

                   pad="ih*16/9:ih:(ow-iw)/2:(oh-ih)/2"

       •   In case of anamorphic video, in order to set the output display aspect correctly, it is necessary to use sar in the
           expression, according to the relation:

                   (ih * X / ih) * sar = output_dar
                   X = output_dar / sar

           Thus the previous example needs to be modified to:

                   pad="ih*16/9/sar:ih:(ow-iw)/2:(oh-ih)/2"

       •   Double the output size and put the input video in the bottom-right corner of the output padded area:

                   pad="2*iw:2*ih:ow-iw:oh-ih"

   palettegen
       Generate one palette for a whole video stream.

       It accepts the following options:

       max_colors
           Set the maximum number of colors to quantize in the palette.  Note: the palette will still contain 256 colors; the
           unused palette entries will be black.

       reserve_transparent
           Create a palette of 255 colors maximum and reserve the last one for transparency. Reserving the transparency color is
           useful for GIF optimization.  If not set, the maximum of colors in the palette will be 256. You probably want to disable
           this option for a standalone image.  Set by default.

       transparency_color
           Set the color that will be used as background for transparency.

       stats_mode
           Set statistics mode.

           It accepts the following values:

           full
               Compute full frame histograms.

           diff
               Compute histograms only for the part that differs from previous frame. This might be relevant to give more
               importance to the moving part of your input if the background is static.

           single
               Compute new histogram for each frame.

           Default value is full.

       use_alpha
           Create a palette of colors with alpha components.  Setting this, will automatically disable 'reserve_transparent'.

       The filter also exports the frame metadata "lavfi.color_quant_ratio" ("nb_color_in / nb_color_out") which you can use to
       evaluate the degree of color quantization of the palette. This information is also visible at info logging level.

       Examples

       •   Generate a representative palette of a given video using ffmpeg:

                   ffmpeg -i input.mkv -vf palettegen palette.png

   paletteuse
       Use a palette to downsample an input video stream.

       The filter takes two inputs: one video stream and a palette. The palette must be a 256 pixels image.

       It accepts the following options:

       dither
           Select dithering mode. Available algorithms are:

           bayer
               Ordered 8x8 bayer dithering (deterministic)

           heckbert
               Dithering as defined by Paul Heckbert in 1982 (simple error diffusion).  Note: this dithering is sometimes
               considered "wrong" and is included as a reference.

           floyd_steinberg
               Floyd and Steingberg dithering (error diffusion)

           sierra2
               Frankie Sierra dithering v2 (error diffusion)

           sierra2_4a
               Frankie Sierra dithering v2 "Lite" (error diffusion)

           Default is sierra2_4a.

       bayer_scale
           When bayer dithering is selected, this option defines the scale of the pattern (how much the crosshatch pattern is
           visible). A low value means more visible pattern for less banding, and higher value means less visible pattern at the
           cost of more banding.

           The option must be an integer value in the range [0,5]. Default is 2.

       diff_mode
           If set, define the zone to process

           rectangle
               Only the changing rectangle will be reprocessed. This is similar to GIF cropping/offsetting compression mechanism.
               This option can be useful for speed if only a part of the image is changing, and has use cases such as limiting the
               scope of the error diffusal dither to the rectangle that bounds the moving scene (it leads to more deterministic
               output if the scene doesn't change much, and as a result less moving noise and better GIF compression).

           Default is none.

       new Take new palette for each output frame.

       alpha_threshold
           Sets the alpha threshold for transparency. Alpha values above this threshold will be treated as completely opaque, and
           values below this threshold will be treated as completely transparent.

           The option must be an integer value in the range [0,255]. Default is 128.

       use_alpha
           Apply the palette by taking alpha values into account. Only useful with palettes that are containing multiple colors
           with alpha components.  Setting this will automatically disable 'alpha_treshold'.

       Examples

       •   Use a palette (generated for example with palettegen) to encode a GIF using ffmpeg:

                   ffmpeg -i input.mkv -i palette.png -lavfi paletteuse output.gif

   perspective
       Correct perspective of video not recorded perpendicular to the screen.

       A description of the accepted parameters follows.

       x0
       y0
       x1
       y1
       x2
       y2
       x3
       y3  Set coordinates expression for top left, top right, bottom left and bottom right corners.  Default values are
           "0:0:W:0:0:H:W:H" with which perspective will remain unchanged.  If the "sense" option is set to "source", then the
           specified points will be sent to the corners of the destination. If the "sense" option is set to "destination", then the
           corners of the source will be sent to the specified coordinates.

           The expressions can use the following variables:

           W
           H   the width and height of video frame.

           in  Input frame count.

           on  Output frame count.

       interpolation
           Set interpolation for perspective correction.

           It accepts the following values:

           linear
           cubic

           Default value is linear.

       sense
           Set interpretation of coordinate options.

           It accepts the following values:

           0, source
               Send point in the source specified by the given coordinates to the corners of the destination.

           1, destination
               Send the corners of the source to the point in the destination specified by the given coordinates.

               Default value is source.

       eval
           Set when the expressions for coordinates x0,y0,...x3,y3 are evaluated.

           It accepts the following values:

           init
               only evaluate expressions once during the filter initialization or when a command is processed

           frame
               evaluate expressions for each incoming frame

           Default value is init.

   phase
       Delay interlaced video by one field time so that the field order changes.

       The intended use is to fix PAL movies that have been captured with the opposite field order to the film-to-video transfer.

       A description of the accepted parameters follows.

       mode
           Set phase mode.

           It accepts the following values:

           t   Capture field order top-first, transfer bottom-first.  Filter will delay the bottom field.

           b   Capture field order bottom-first, transfer top-first.  Filter will delay the top field.

           p   Capture and transfer with the same field order. This mode only exists for the documentation of the other options to
               refer to, but if you actually select it, the filter will faithfully do nothing.

           a   Capture field order determined automatically by field flags, transfer opposite.  Filter selects among t and b modes
               on a frame by frame basis using field flags. If no field information is available, then this works just like u.

           u   Capture unknown or varying, transfer opposite.  Filter selects among t and b on a frame by frame basis by analyzing
               the images and selecting the alternative that produces best match between the fields.

           T   Capture top-first, transfer unknown or varying.  Filter selects among t and p using image analysis.

           B   Capture bottom-first, transfer unknown or varying.  Filter selects among b and p using image analysis.

           A   Capture determined by field flags, transfer unknown or varying.  Filter selects among t, b and p using field flags
               and image analysis. If no field information is available, then this works just like U. This is the default mode.

           U   Both capture and transfer unknown or varying.  Filter selects among t, b and p using image analysis only.

       Commands

       This filter supports the all above options as commands.

   photosensitivity
       Reduce various flashes in video, so to help users with epilepsy.

       It accepts the following options:

       frames, f
           Set how many frames to use when filtering. Default is 30.

       threshold, t
           Set detection threshold factor. Default is 1.  Lower is stricter.

       skip
           Set how many pixels to skip when sampling frames. Default is 1.  Allowed range is from 1 to 1024.

       bypass
           Leave frames unchanged. Default is disabled.

   pixdesctest
       Pixel format descriptor test filter, mainly useful for internal testing. The output video should be equal to the input
       video.

       For example:

               format=monow, pixdesctest

       can be used to test the monowhite pixel format descriptor definition.

   pixelize
       Apply pixelization to video stream.

       The filter accepts the following options:

       width, w
       height, h
           Set block dimensions that will be used for pixelization.  Default value is 16.

       mode, m
           Set the mode of pixelization used.

           Possible values are:

           avg
           min
           max

           Default value is "avg".

       planes, p
           Set what planes to filter. Default is to filter all planes.

       Commands

       This filter supports all options as commands.

   pixscope
       Display sample values of color channels. Mainly useful for checking color and levels. Minimum supported resolution is
       640x480.

       The filters accept the following options:

       x   Set scope X position, relative offset on X axis.

       y   Set scope Y position, relative offset on Y axis.

       w   Set scope width.

       h   Set scope height.

       o   Set window opacity. This window also holds statistics about pixel area.

       wx  Set window X position, relative offset on X axis.

       wy  Set window Y position, relative offset on Y axis.

       Commands

       This filter supports same commands as options.

   pp
       Enable the specified chain of postprocessing subfilters using libpostproc. This library should be automatically selected
       with a GPL build ("--enable-gpl").  Subfilters must be separated by '/' and can be disabled by prepending a '-'.  Each
       subfilter and some options have a short and a long name that can be used interchangeably, i.e. dr/dering are the same.

       The filters accept the following options:

       subfilters
           Set postprocessing subfilters string.

       All subfilters share common options to determine their scope:

       a/autoq
           Honor the quality commands for this subfilter.

       c/chrom
           Do chrominance filtering, too (default).

       y/nochrom
           Do luminance filtering only (no chrominance).

       n/noluma
           Do chrominance filtering only (no luminance).

       These options can be appended after the subfilter name, separated by a '|'.

       Available subfilters are:

       hb/hdeblock[|difference[|flatness]]
           Horizontal deblocking filter

           difference
               Difference factor where higher values mean more deblocking (default: 32).

           flatness
               Flatness threshold where lower values mean more deblocking (default: 39).

       vb/vdeblock[|difference[|flatness]]
           Vertical deblocking filter

           difference
               Difference factor where higher values mean more deblocking (default: 32).

           flatness
               Flatness threshold where lower values mean more deblocking (default: 39).

       ha/hadeblock[|difference[|flatness]]
           Accurate horizontal deblocking filter

           difference
               Difference factor where higher values mean more deblocking (default: 32).

           flatness
               Flatness threshold where lower values mean more deblocking (default: 39).

       va/vadeblock[|difference[|flatness]]
           Accurate vertical deblocking filter

           difference
               Difference factor where higher values mean more deblocking (default: 32).

           flatness
               Flatness threshold where lower values mean more deblocking (default: 39).

       The horizontal and vertical deblocking filters share the difference and flatness values so you cannot set different
       horizontal and vertical thresholds.

       h1/x1hdeblock
           Experimental horizontal deblocking filter

       v1/x1vdeblock
           Experimental vertical deblocking filter

       dr/dering
           Deringing filter

       tn/tmpnoise[|threshold1[|threshold2[|threshold3]]], temporal noise reducer
           threshold1
               larger -> stronger filtering

           threshold2
               larger -> stronger filtering

           threshold3
               larger -> stronger filtering

       al/autolevels[:f/fullyrange], automatic brightness / contrast correction
           f/fullyrange
               Stretch luminance to "0-255".

       lb/linblenddeint
           Linear blend deinterlacing filter that deinterlaces the given block by filtering all lines with a "(1 2 1)" filter.

       li/linipoldeint
           Linear interpolating deinterlacing filter that deinterlaces the given block by linearly interpolating every second line.

       ci/cubicipoldeint
           Cubic interpolating deinterlacing filter deinterlaces the given block by cubically interpolating every second line.

       md/mediandeint
           Median deinterlacing filter that deinterlaces the given block by applying a median filter to every second line.

       fd/ffmpegdeint
           FFmpeg deinterlacing filter that deinterlaces the given block by filtering every second line with a "(-1 4 2 4 -1)"
           filter.

       l5/lowpass5
           Vertically applied FIR lowpass deinterlacing filter that deinterlaces the given block by filtering all lines with a "(-1
           2 6 2 -1)" filter.

       fq/forceQuant[|quantizer]
           Overrides the quantizer table from the input with the constant quantizer you specify.

           quantizer
               Quantizer to use

       de/default
           Default pp filter combination ("hb|a,vb|a,dr|a")

       fa/fast
           Fast pp filter combination ("h1|a,v1|a,dr|a")

       ac  High quality pp filter combination ("ha|a|128|7,va|a,dr|a")

       Examples

       •   Apply horizontal and vertical deblocking, deringing and automatic brightness/contrast:

                   pp=hb/vb/dr/al

       •   Apply default filters without brightness/contrast correction:

                   pp=de/-al

       •   Apply default filters and temporal denoiser:

                   pp=default/tmpnoise|1|2|3

       •   Apply deblocking on luminance only, and switch vertical deblocking on or off automatically depending on available CPU
           time:

                   pp=hb|y/vb|a

   pp7
       Apply Postprocessing filter 7. It is variant of the spp filter, similar to spp = 6 with 7 point DCT, where only the center
       sample is used after IDCT.

       The filter accepts the following options:

       qp  Force a constant quantization parameter. It accepts an integer in range 0 to 63. If not set, the filter will use the QP
           from the video stream (if available).

       mode
           Set thresholding mode. Available modes are:

           hard
               Set hard thresholding.

           soft
               Set soft thresholding (better de-ringing effect, but likely blurrier).

           medium
               Set medium thresholding (good results, default).

   premultiply
       Apply alpha premultiply effect to input video stream using first plane of second stream as alpha.

       Both streams must have same dimensions and same pixel format.

       The filter accepts the following option:

       planes
           Set which planes will be processed, unprocessed planes will be copied.  By default value 0xf, all planes will be
           processed.

       inplace
           Do not require 2nd input for processing, instead use alpha plane from input stream.

   prewitt
       Apply prewitt operator to input video stream.

       The filter accepts the following option:

       planes
           Set which planes will be processed, unprocessed planes will be copied.  By default value 0xf, all planes will be
           processed.

       scale
           Set value which will be multiplied with filtered result.

       delta
           Set value which will be added to filtered result.

       Commands

       This filter supports the all above options as commands.

   pseudocolor
       Alter frame colors in video with pseudocolors.

       This filter accepts the following options:

       c0  set pixel first component expression

       c1  set pixel second component expression

       c2  set pixel third component expression

       c3  set pixel fourth component expression, corresponds to the alpha component

       index, i
           set component to use as base for altering colors

       preset, p
           Pick one of built-in LUTs. By default is set to none.

           Available LUTs:

           magma
           inferno
           plasma
           viridis
           turbo
           cividis
           range1
           range2
           shadows
           highlights
           solar
           nominal
           preferred
           total
       opacity
           Set opacity of output colors. Allowed range is from 0 to 1.  Default value is set to 1.

       Each of the expression options specifies the expression to use for computing the lookup table for the corresponding pixel
       component values.

       The expressions can contain the following constants and functions:

       w
       h   The input width and height.

       val The input value for the pixel component.

       ymin, umin, vmin, amin
           The minimum allowed component value.

       ymax, umax, vmax, amax
           The maximum allowed component value.

       All expressions default to "val".

       Commands

       This filter supports the all above options as commands.

       Examples

       •   Change too high luma values to gradient:

                   pseudocolor="'if(between(val,ymax,amax),lerp(ymin,ymax,(val-ymax)/(amax-ymax)),-1):if(between(val,ymax,amax),lerp(umax,umin,(val-ymax)/(amax-ymax)),-1):if(between(val,ymax,amax),lerp(vmin,vmax,(val-ymax)/(amax-ymax)),-1):-1'"

   psnr
       Obtain the average, maximum and minimum PSNR (Peak Signal to Noise Ratio) between two input videos.

       This filter takes in input two input videos, the first input is considered the "main" source and is passed unchanged to the
       output. The second input is used as a "reference" video for computing the PSNR.

       Both video inputs must have the same resolution and pixel format for this filter to work correctly. Also it assumes that
       both inputs have the same number of frames, which are compared one by one.

       The obtained average PSNR is printed through the logging system.

       The filter stores the accumulated MSE (mean squared error) of each frame, and at the end of the processing it is averaged
       across all frames equally, and the following formula is applied to obtain the PSNR:

               PSNR = 10*log10(MAX^2/MSE)

       Where MAX is the average of the maximum values of each component of the image.

       The description of the accepted parameters follows.

       stats_file, f
           If specified the filter will use the named file to save the PSNR of each individual frame. When filename equals "-" the
           data is sent to standard output.

       stats_version
           Specifies which version of the stats file format to use. Details of each format are written below.  Default value is 1.

       stats_add_max
           Determines whether the max value is output to the stats log.  Default value is 0.  Requires stats_version >= 2. If this
           is set and stats_version < 2, the filter will return an error.

       This filter also supports the framesync options.

       The file printed if stats_file is selected, contains a sequence of key/value pairs of the form key:value for each compared
       couple of frames.

       If a stats_version greater than 1 is specified, a header line precedes the list of per-frame-pair stats, with key value
       pairs following the frame format with the following parameters:

       psnr_log_version
           The version of the log file format. Will match stats_version.

       fields
           A comma separated list of the per-frame-pair parameters included in the log.

       A description of each shown per-frame-pair parameter follows:

       n   sequential number of the input frame, starting from 1

       mse_avg
           Mean Square Error pixel-by-pixel average difference of the compared frames, averaged over all the image components.

       mse_y, mse_u, mse_v, mse_r, mse_g, mse_b, mse_a
           Mean Square Error pixel-by-pixel average difference of the compared frames for the component specified by the suffix.

       psnr_y, psnr_u, psnr_v, psnr_r, psnr_g, psnr_b, psnr_a
           Peak Signal to Noise ratio of the compared frames for the component specified by the suffix.

       max_avg, max_y, max_u, max_v
           Maximum allowed value for each channel, and average over all channels.

       Examples

       •   For example:

                   movie=ref_movie.mpg, setpts=PTS-STARTPTS [main];
                   [main][ref] psnr="stats_file=stats.log" [out]

           On this example the input file being processed is compared with the reference file ref_movie.mpg. The PSNR of each
           individual frame is stored in stats.log.

       •   Another example with different containers:

                   ffmpeg -i main.mpg -i ref.mkv -lavfi  "[0:v]settb=AVTB,setpts=PTS-STARTPTS[main];[1:v]settb=AVTB,setpts=PTS-STARTPTS[ref];[main][ref]psnr" -f null -

   pullup
       Pulldown reversal (inverse telecine) filter, capable of handling mixed hard-telecine, 24000/1001 fps progressive, and
       30000/1001 fps progressive content.

       The pullup filter is designed to take advantage of future context in making its decisions. This filter is stateless in the
       sense that it does not lock onto a pattern to follow, but it instead looks forward to the following fields in order to
       identify matches and rebuild progressive frames.

       To produce content with an even framerate, insert the fps filter after pullup, use "fps=24000/1001" if the input frame rate
       is 29.97fps, "fps=24" for 30fps and the (rare) telecined 25fps input.

       The filter accepts the following options:

       jl
       jr
       jt
       jb  These options set the amount of "junk" to ignore at the left, right, top, and bottom of the image, respectively. Left
           and right are in units of 8 pixels, while top and bottom are in units of 2 lines.  The default is 8 pixels on each side.

       sb  Set the strict breaks. Setting this option to 1 will reduce the chances of filter generating an occasional mismatched
           frame, but it may also cause an excessive number of frames to be dropped during high motion sequences.  Conversely,
           setting it to -1 will make filter match fields more easily.  This may help processing of video where there is slight
           blurring between the fields, but may also cause there to be interlaced frames in the output.  Default value is 0.

       mp  Set the metric plane to use. It accepts the following values:

           l   Use luma plane.

           u   Use chroma blue plane.

           v   Use chroma red plane.

           This option may be set to use chroma plane instead of the default luma plane for doing filter's computations. This may
           improve accuracy on very clean source material, but more likely will decrease accuracy, especially if there is chroma
           noise (rainbow effect) or any grayscale video.  The main purpose of setting mp to a chroma plane is to reduce CPU load
           and make pullup usable in realtime on slow machines.

       For best results (without duplicated frames in the output file) it is necessary to change the output frame rate. For
       example, to inverse telecine NTSC input:

               ffmpeg -i input -vf pullup -r 24000/1001 ...

   qp
       Change video quantization parameters (QP).

       The filter accepts the following option:

       qp  Set expression for quantization parameter.

       The expression is evaluated through the eval API and can contain, among others, the following constants:

       known
           1 if index is not 129, 0 otherwise.

       qp  Sequential index starting from -129 to 128.

       Examples

       •   Some equation like:

                   qp=2+2*sin(PI*qp)

   random
       Flush video frames from internal cache of frames into a random order.  No frame is discarded.  Inspired by frei0r nervous
       filter.

       frames
           Set size in number of frames of internal cache, in range from 2 to 512. Default is 30.

       seed
           Set seed for random number generator, must be an integer included between 0 and "UINT32_MAX". If not specified, or if
           explicitly set to less than 0, the filter will try to use a good random seed on a best effort basis.

   readeia608
       Read closed captioning (EIA-608) information from the top lines of a video frame.

       This filter adds frame metadata for "lavfi.readeia608.X.cc" and "lavfi.readeia608.X.line", where "X" is the number of the
       identified line with EIA-608 data (starting from 0). A description of each metadata value follows:

       lavfi.readeia608.X.cc
           The two bytes stored as EIA-608 data (printed in hexadecimal).

       lavfi.readeia608.X.line
           The number of the line on which the EIA-608 data was identified and read.

       This filter accepts the following options:

       scan_min
           Set the line to start scanning for EIA-608 data. Default is 0.

       scan_max
           Set the line to end scanning for EIA-608 data. Default is 29.

       spw Set the ratio of width reserved for sync code detection.  Default is 0.27. Allowed range is "[0.1 - 0.7]".

       chp Enable checking the parity bit. In the event of a parity error, the filter will output 0x00 for that character. Default
           is false.

       lp  Lowpass lines prior to further processing. Default is enabled.

       Commands

       This filter supports the all above options as commands.

       Examples

       •   Output a csv with presentation time and the first two lines of identified EIA-608 captioning data.

                   ffprobe -f lavfi -i movie=captioned_video.mov,readeia608 -show_entries frame=pts_time:frame_tags=lavfi.readeia608.0.cc,lavfi.readeia608.1.cc -of csv

   readvitc
       Read vertical interval timecode (VITC) information from the top lines of a video frame.

       The filter adds frame metadata key "lavfi.readvitc.tc_str" with the timecode value, if a valid timecode has been detected.
       Further metadata key "lavfi.readvitc.found" is set to 0/1 depending on whether timecode data has been found or not.

       This filter accepts the following options:

       scan_max
           Set the maximum number of lines to scan for VITC data. If the value is set to "-1" the full video frame is scanned.
           Default is 45.

       thr_b
           Set the luma threshold for black. Accepts float numbers in the range [0.0,1.0], default value is 0.2. The value must be
           equal or less than "thr_w".

       thr_w
           Set the luma threshold for white. Accepts float numbers in the range [0.0,1.0], default value is 0.6. The value must be
           equal or greater than "thr_b".

       Examples

       •   Detect and draw VITC data onto the video frame; if no valid VITC is detected, draw "--:--:--:--" as a placeholder:

                   ffmpeg -i input.avi -filter:v 'readvitc,drawtext=fontfile=FreeMono.ttf:text=%{metadata\\:lavfi.readvitc.tc_str\\:--\\\\\\:--\\\\\\:--\\\\\\:--}:x=(w-tw)/2:y=400-ascent'

   remap
       Remap pixels using 2nd: Xmap and 3rd: Ymap input video stream.

       Destination pixel at position (X, Y) will be picked from source (x, y) position where x = Xmap(X, Y) and y = Ymap(X, Y). If
       mapping values are out of range, zero value for pixel will be used for destination pixel.

       Xmap and Ymap input video streams must be of same dimensions. Output video stream will have Xmap/Ymap video stream
       dimensions.  Xmap and Ymap input video streams are 16bit depth, single channel.

       format
           Specify pixel format of output from this filter. Can be "color" or "gray".  Default is "color".

       fill
           Specify the color of the unmapped pixels. For the syntax of this option, check the "Color" section in the ffmpeg-utils
           manual. Default color is "black".

   removegrain
       The removegrain filter is a spatial denoiser for progressive video.

       m0  Set mode for the first plane.

       m1  Set mode for the second plane.

       m2  Set mode for the third plane.

       m3  Set mode for the fourth plane.

       Range of mode is from 0 to 24. Description of each mode follows:

       0   Leave input plane unchanged. Default.

       1   Clips the pixel with the minimum and maximum of the 8 neighbour pixels.

       2   Clips the pixel with the second minimum and maximum of the 8 neighbour pixels.

       3   Clips the pixel with the third minimum and maximum of the 8 neighbour pixels.

       4   Clips the pixel with the fourth minimum and maximum of the 8 neighbour pixels.  This is equivalent to a median filter.

       5   Line-sensitive clipping giving the minimal change.

       6   Line-sensitive clipping, intermediate.

       7   Line-sensitive clipping, intermediate.

       8   Line-sensitive clipping, intermediate.

       9   Line-sensitive clipping on a line where the neighbours pixels are the closest.

       10  Replaces the target pixel with the closest neighbour.

       11  [1 2 1] horizontal and vertical kernel blur.

       12  Same as mode 11.

       13  Bob mode, interpolates top field from the line where the neighbours pixels are the closest.

       14  Bob mode, interpolates bottom field from the line where the neighbours pixels are the closest.

       15  Bob mode, interpolates top field. Same as 13 but with a more complicated interpolation formula.

       16  Bob mode, interpolates bottom field. Same as 14 but with a more complicated interpolation formula.

       17  Clips the pixel with the minimum and maximum of respectively the maximum and minimum of each pair of opposite neighbour
           pixels.

       18  Line-sensitive clipping using opposite neighbours whose greatest distance from the current pixel is minimal.

       19  Replaces the pixel with the average of its 8 neighbours.

       20  Averages the 9 pixels ([1 1 1] horizontal and vertical blur).

       21  Clips pixels using the averages of opposite neighbour.

       22  Same as mode 21 but simpler and faster.

       23  Small edge and halo removal, but reputed useless.

       24  Similar as 23.

   removelogo
       Suppress a TV station logo, using an image file to determine which pixels comprise the logo. It works by filling in the
       pixels that comprise the logo with neighboring pixels.

       The filter accepts the following options:

       filename, f
           Set the filter bitmap file, which can be any image format supported by libavformat. The width and height of the image
           file must match those of the video stream being processed.

       Pixels in the provided bitmap image with a value of zero are not considered part of the logo, non-zero pixels are considered
       part of the logo. If you use white (255) for the logo and black (0) for the rest, you will be safe. For making the filter
       bitmap, it is recommended to take a screen capture of a black frame with the logo visible, and then using a threshold filter
       followed by the erode filter once or twice.

       If needed, little splotches can be fixed manually. Remember that if logo pixels are not covered, the filter quality will be
       much reduced. Marking too many pixels as part of the logo does not hurt as much, but it will increase the amount of blurring
       needed to cover over the image and will destroy more information than necessary, and extra pixels will slow things down on a
       large logo.

   repeatfields
       This filter uses the repeat_field flag from the Video ES headers and hard repeats fields based on its value.

   reverse
       Reverse a video clip.

       Warning: This filter requires memory to buffer the entire clip, so trimming is suggested.

       Examples

       •   Take the first 5 seconds of a clip, and reverse it.

                   trim=end=5,reverse

   rgbashift
       Shift R/G/B/A pixels horizontally and/or vertically.

       The filter accepts the following options:

       rh  Set amount to shift red horizontally.

       rv  Set amount to shift red vertically.

       gh  Set amount to shift green horizontally.

       gv  Set amount to shift green vertically.

       bh  Set amount to shift blue horizontally.

       bv  Set amount to shift blue vertically.

       ah  Set amount to shift alpha horizontally.

       av  Set amount to shift alpha vertically.

       edge
           Set edge mode, can be smear, default, or warp.

       Commands

       This filter supports the all above options as commands.

   roberts
       Apply roberts cross operator to input video stream.

       The filter accepts the following option:

       planes
           Set which planes will be processed, unprocessed planes will be copied.  By default value 0xf, all planes will be
           processed.

       scale
           Set value which will be multiplied with filtered result.

       delta
           Set value which will be added to filtered result.

       Commands

       This filter supports the all above options as commands.

   rotate
       Rotate video by an arbitrary angle expressed in radians.

       The filter accepts the following options:

       A description of the optional parameters follows.

       angle, a
           Set an expression for the angle by which to rotate the input video clockwise, expressed as a number of radians. A
           negative value will result in a counter-clockwise rotation. By default it is set to "0".

           This expression is evaluated for each frame.

       out_w, ow
           Set the output width expression, default value is "iw".  This expression is evaluated just once during configuration.

       out_h, oh
           Set the output height expression, default value is "ih".  This expression is evaluated just once during configuration.

       bilinear
           Enable bilinear interpolation if set to 1, a value of 0 disables it. Default value is 1.

       fillcolor, c
           Set the color used to fill the output area not covered by the rotated image. For the general syntax of this option,
           check the "Color" section in the ffmpeg-utils manual.  If the special value "none" is selected then no background is
           printed (useful for example if the background is never shown).

           Default value is "black".

       The expressions for the angle and the output size can contain the following constants and functions:

       n   sequential number of the input frame, starting from 0. It is always NAN before the first frame is filtered.

       t   time in seconds of the input frame, it is set to 0 when the filter is configured. It is always NAN before the first
           frame is filtered.

       hsub
       vsub
           horizontal and vertical chroma subsample values. For example for the pixel format "yuv422p" hsub is 2 and vsub is 1.

       in_w, iw
       in_h, ih
           the input video width and height

       out_w, ow
       out_h, oh
           the output width and height, that is the size of the padded area as specified by the width and height expressions

       rotw(a)
       roth(a)
           the minimal width/height required for completely containing the input video rotated by a radians.

           These are only available when computing the out_w and out_h expressions.

       Examples

       •   Rotate the input by PI/6 radians clockwise:

                   rotate=PI/6

       •   Rotate the input by PI/6 radians counter-clockwise:

                   rotate=-PI/6

       •   Rotate the input by 45 degrees clockwise:

                   rotate=45*PI/180

       •   Apply a constant rotation with period T, starting from an angle of PI/3:

                   rotate=PI/3+2*PI*t/T

       •   Make the input video rotation oscillating with a period of T seconds and an amplitude of A radians:

                   rotate=A*sin(2*PI/T*t)

       •   Rotate the video, output size is chosen so that the whole rotating input video is always completely contained in the
           output:

                   rotate='2*PI*t:ow=hypot(iw,ih):oh=ow'

       •   Rotate the video, reduce the output size so that no background is ever shown:

                   rotate=2*PI*t:ow='min(iw,ih)/sqrt(2)':oh=ow:c=none

       Commands

       The filter supports the following commands:

       a, angle
           Set the angle expression.  The command accepts the same syntax of the corresponding option.

           If the specified expression is not valid, it is kept at its current value.

   sab
       Apply Shape Adaptive Blur.

       The filter accepts the following options:

       luma_radius, lr
           Set luma blur filter strength, must be a value in range 0.1-4.0, default value is 1.0. A greater value will result in a
           more blurred image, and in slower processing.

       luma_pre_filter_radius, lpfr
           Set luma pre-filter radius, must be a value in the 0.1-2.0 range, default value is 1.0.

       luma_strength, ls
           Set luma maximum difference between pixels to still be considered, must be a value in the 0.1-100.0 range, default value
           is 1.0.

       chroma_radius, cr
           Set chroma blur filter strength, must be a value in range -0.9-4.0. A greater value will result in a more blurred image,
           and in slower processing.

       chroma_pre_filter_radius, cpfr
           Set chroma pre-filter radius, must be a value in the -0.9-2.0 range.

       chroma_strength, cs
           Set chroma maximum difference between pixels to still be considered, must be a value in the -0.9-100.0 range.

       Each chroma option value, if not explicitly specified, is set to the corresponding luma option value.

   scale
       Scale (resize) the input video, using the libswscale library.

       The scale filter forces the output display aspect ratio to be the same of the input, by changing the output sample aspect
       ratio.

       If the input image format is different from the format requested by the next filter, the scale filter will convert the input
       to the requested format.

       Options

       The filter accepts the following options, or any of the options supported by the libswscale scaler.

       See the ffmpeg-scaler manual for the complete list of scaler options.

       width, w
       height, h
           Set the output video dimension expression. Default value is the input dimension.

           If the width or w value is 0, the input width is used for the output. If the height or h value is 0, the input height is
           used for the output.

           If one and only one of the values is -n with n >= 1, the scale filter will use a value that maintains the aspect ratio
           of the input image, calculated from the other specified dimension. After that it will, however, make sure that the
           calculated dimension is divisible by n and adjust the value if necessary.

           If both values are -n with n >= 1, the behavior will be identical to both values being set to 0 as previously detailed.

           See below for the list of accepted constants for use in the dimension expression.

       eval
           Specify when to evaluate width and height expression. It accepts the following values:

           init
               Only evaluate expressions once during the filter initialization or when a command is processed.

           frame
               Evaluate expressions for each incoming frame.

           Default value is init.

       interl
           Set the interlacing mode. It accepts the following values:

           1   Force interlaced aware scaling.

           0   Do not apply interlaced scaling.

           -1  Select interlaced aware scaling depending on whether the source frames are flagged as interlaced or not.

           Default value is 0.

       flags
           Set libswscale scaling flags. See the ffmpeg-scaler manual for the complete list of values. If not explicitly specified
           the filter applies the default flags.

       param0, param1
           Set libswscale input parameters for scaling algorithms that need them. See the ffmpeg-scaler manual for the complete
           documentation. If not explicitly specified the filter applies empty parameters.

       size, s
           Set the video size. For the syntax of this option, check the "Video size" section in the ffmpeg-utils manual.

       in_color_matrix
       out_color_matrix
           Set in/output YCbCr color space type.

           This allows the autodetected value to be overridden as well as allows forcing a specific value used for the output and
           encoder.

           If not specified, the color space type depends on the pixel format.

           Possible values:

           auto
               Choose automatically.

           bt709
               Format conforming to International Telecommunication Union (ITU) Recommendation BT.709.

           fcc Set color space conforming to the United States Federal Communications Commission (FCC) Code of Federal Regulations
               (CFR) Title 47 (2003) 73.682 (a).

           bt601
           bt470
           smpte170m
               Set color space conforming to:

               •   ITU Radiocommunication Sector (ITU-R) Recommendation BT.601

               •   ITU-R Rec. BT.470-6 (1998) Systems B, B1, and G

               •   Society of Motion Picture and Television Engineers (SMPTE) ST 170:2004

           smpte240m
               Set color space conforming to SMPTE ST 240:1999.

           bt2020
               Set color space conforming to ITU-R BT.2020 non-constant luminance system.

       in_range
       out_range
           Set in/output YCbCr sample range.

           This allows the autodetected value to be overridden as well as allows forcing a specific value used for the output and
           encoder. If not specified, the range depends on the pixel format. Possible values:

           auto/unknown
               Choose automatically.

           jpeg/full/pc
               Set full range (0-255 in case of 8-bit luma).

           mpeg/limited/tv
               Set "MPEG" range (16-235 in case of 8-bit luma).

       force_original_aspect_ratio
           Enable decreasing or increasing output video width or height if necessary to keep the original aspect ratio. Possible
           values:

           disable
               Scale the video as specified and disable this feature.

           decrease
               The output video dimensions will automatically be decreased if needed.

           increase
               The output video dimensions will automatically be increased if needed.

           One useful instance of this option is that when you know a specific device's maximum allowed resolution, you can use
           this to limit the output video to that, while retaining the aspect ratio. For example, device A allows 1280x720
           playback, and your video is 1920x800. Using this option (set it to decrease) and specifying 1280x720 to the command line
           makes the output 1280x533.

           Please note that this is a different thing than specifying -1 for w or h, you still need to specify the output
           resolution for this option to work.

       force_divisible_by
           Ensures that both the output dimensions, width and height, are divisible by the given integer when used together with
           force_original_aspect_ratio. This works similar to using "-n" in the w and h options.

           This option respects the value set for force_original_aspect_ratio, increasing or decreasing the resolution accordingly.
           The video's aspect ratio may be slightly modified.

           This option can be handy if you need to have a video fit within or exceed a defined resolution using
           force_original_aspect_ratio but also have encoder restrictions on width or height divisibility.

       The values of the w and h options are expressions containing the following constants:

       in_w
       in_h
           The input width and height

       iw
       ih  These are the same as in_w and in_h.

       out_w
       out_h
           The output (scaled) width and height

       ow
       oh  These are the same as out_w and out_h

       a   The same as iw / ih

       sar input sample aspect ratio

       dar The input display aspect ratio. Calculated from "(iw / ih) * sar".

       hsub
       vsub
           horizontal and vertical input chroma subsample values. For example for the pixel format "yuv422p" hsub is 2 and vsub is
           1.

       ohsub
       ovsub
           horizontal and vertical output chroma subsample values. For example for the pixel format "yuv422p" hsub is 2 and vsub is
           1.

       n   The (sequential) number of the input frame, starting from 0.  Only available with "eval=frame".

       t   The presentation timestamp of the input frame, expressed as a number of seconds. Only available with "eval=frame".

       pos The position (byte offset) of the frame in the input stream, or NaN if this information is unavailable and/or
           meaningless (for example in case of synthetic video).  Only available with "eval=frame".

       Examples

       •   Scale the input video to a size of 200x100

                   scale=w=200:h=100

           This is equivalent to:

                   scale=200:100

           or:

                   scale=200x100

       •   Specify a size abbreviation for the output size:

                   scale=qcif

           which can also be written as:

                   scale=size=qcif

       •   Scale the input to 2x:

                   scale=w=2*iw:h=2*ih

       •   The above is the same as:

                   scale=2*in_w:2*in_h

       •   Scale the input to 2x with forced interlaced scaling:

                   scale=2*iw:2*ih:interl=1

       •   Scale the input to half size:

                   scale=w=iw/2:h=ih/2

       •   Increase the width, and set the height to the same size:

                   scale=3/2*iw:ow

       •   Seek Greek harmony:

                   scale=iw:1/PHI*iw
                   scale=ih*PHI:ih

       •   Increase the height, and set the width to 3/2 of the height:

                   scale=w=3/2*oh:h=3/5*ih

       •   Increase the size, making the size a multiple of the chroma subsample values:

                   scale="trunc(3/2*iw/hsub)*hsub:trunc(3/2*ih/vsub)*vsub"

       •   Increase the width to a maximum of 500 pixels, keeping the same aspect ratio as the input:

                   scale=w='min(500\, iw*3/2):h=-1'

       •   Make pixels square by combining scale and setsar:

                   scale='trunc(ih*dar):ih',setsar=1/1

       •   Make pixels square by combining scale and setsar, making sure the resulting resolution is even (required by some
           codecs):

                   scale='trunc(ih*dar/2)*2:trunc(ih/2)*2',setsar=1/1

       Commands

       This filter supports the following commands:

       width, w
       height, h
           Set the output video dimension expression.  The command accepts the same syntax of the corresponding option.

           If the specified expression is not valid, it is kept at its current value.

   scale_cuda
       Scale (resize) and convert (pixel format) the input video, using accelerated CUDA kernels.  Setting the output width and
       height works in the same way as for the scale filter.

       The filter accepts the following options:

       w
       h   Set the output video dimension expression. Default value is the input dimension.

           Allows for the same expressions as the scale filter.

       interp_algo
           Sets the algorithm used for scaling:

           nearest
               Nearest neighbour

               Used by default if input parameters match the desired output.

           bilinear
               Bilinear

           bicubic
               Bicubic

               This is the default.

           lanczos
               Lanczos

       format
           Controls the output pixel format. By default, or if none is specified, the input pixel format is used.

           The filter does not support converting between YUV and RGB pixel formats.

       passthrough
           If set to 0, every frame is processed, even if no conversion is neccesary.  This mode can be useful to use the filter as
           a buffer for a downstream frame-consumer that exhausts the limited decoder frame pool.

           If set to 1, frames are passed through as-is if they match the desired output parameters. This is the default behaviour.

       param
           Algorithm-Specific parameter.

           Affects the curves of the bicubic algorithm.

       force_original_aspect_ratio
       force_divisible_by
           Work the same as the identical scale filter options.

       Examples

       •   Scale input to 720p, keeping aspect ratio and ensuring the output is yuv420p.

                   scale_cuda=-2:720:format=yuv420p

       •   Upscale to 4K using nearest neighbour algorithm.

                   scale_cuda=4096:2160:interp_algo=nearest

       •   Don't do any conversion or scaling, but copy all input frames into newly allocated ones.  This can be useful to deal
           with a filter and encode chain that otherwise exhausts the decoders frame pool.

                   scale_cuda=passthrough=0

   scale_npp
       Use the NVIDIA Performance Primitives (libnpp) to perform scaling and/or pixel format conversion on CUDA video frames.
       Setting the output width and height works in the same way as for the scale filter.

       The following additional options are accepted:

       format
           The pixel format of the output CUDA frames. If set to the string "same" (the default), the input format will be kept.
           Note that automatic format negotiation and conversion is not yet supported for hardware frames

       interp_algo
           The interpolation algorithm used for resizing. One of the following:

           nn  Nearest neighbour.

           linear
           cubic
           cubic2p_bspline
               2-parameter cubic (B=1, C=0)

           cubic2p_catmullrom
               2-parameter cubic (B=0, C=1/2)

           cubic2p_b05c03
               2-parameter cubic (B=1/2, C=3/10)

           super
               Supersampling

           lanczos
       force_original_aspect_ratio
           Enable decreasing or increasing output video width or height if necessary to keep the original aspect ratio. Possible
           values:

           disable
               Scale the video as specified and disable this feature.

           decrease
               The output video dimensions will automatically be decreased if needed.

           increase
               The output video dimensions will automatically be increased if needed.

           One useful instance of this option is that when you know a specific device's maximum allowed resolution, you can use
           this to limit the output video to that, while retaining the aspect ratio. For example, device A allows 1280x720
           playback, and your video is 1920x800. Using this option (set it to decrease) and specifying 1280x720 to the command line
           makes the output 1280x533.

           Please note that this is a different thing than specifying -1 for w or h, you still need to specify the output
           resolution for this option to work.

       force_divisible_by
           Ensures that both the output dimensions, width and height, are divisible by the given integer when used together with
           force_original_aspect_ratio. This works similar to using "-n" in the w and h options.

           This option respects the value set for force_original_aspect_ratio, increasing or decreasing the resolution accordingly.
           The video's aspect ratio may be slightly modified.

           This option can be handy if you need to have a video fit within or exceed a defined resolution using
           force_original_aspect_ratio but also have encoder restrictions on width or height divisibility.

       eval
           Specify when to evaluate width and height expression. It accepts the following values:

           init
               Only evaluate expressions once during the filter initialization or when a command is processed.

           frame
               Evaluate expressions for each incoming frame.

       The values of the w and h options are expressions containing the following constants:

       in_w
       in_h
           The input width and height

       iw
       ih  These are the same as in_w and in_h.

       out_w
       out_h
           The output (scaled) width and height

       ow
       oh  These are the same as out_w and out_h

       a   The same as iw / ih

       sar input sample aspect ratio

       dar The input display aspect ratio. Calculated from "(iw / ih) * sar".

       n   The (sequential) number of the input frame, starting from 0.  Only available with "eval=frame".

       t   The presentation timestamp of the input frame, expressed as a number of seconds. Only available with "eval=frame".

       pos The position (byte offset) of the frame in the input stream, or NaN if this information is unavailable and/or
           meaningless (for example in case of synthetic video).  Only available with "eval=frame".

   scale2ref
       Scale (resize) the input video, based on a reference video.

       See the scale filter for available options, scale2ref supports the same but uses the reference video instead of the main
       input as basis. scale2ref also supports the following additional constants for the w and h options:

       main_w
       main_h
           The main input video's width and height

       main_a
           The same as main_w / main_h

       main_sar
           The main input video's sample aspect ratio

       main_dar, mdar
           The main input video's display aspect ratio. Calculated from "(main_w / main_h) * main_sar".

       main_hsub
       main_vsub
           The main input video's horizontal and vertical chroma subsample values.  For example for the pixel format "yuv422p" hsub
           is 2 and vsub is 1.

       main_n
           The (sequential) number of the main input frame, starting from 0.  Only available with "eval=frame".

       main_t
           The presentation timestamp of the main input frame, expressed as a number of seconds. Only available with "eval=frame".

       main_pos
           The position (byte offset) of the frame in the main input stream, or NaN if this information is unavailable and/or
           meaningless (for example in case of synthetic video).  Only available with "eval=frame".

       Examples

       •   Scale a subtitle stream (b) to match the main video (a) in size before overlaying

                   'scale2ref[b][a];[a][b]overlay'

       •   Scale a logo to 1/10th the height of a video, while preserving its display aspect ratio.

                   [logo-in][video-in]scale2ref=w=oh*mdar:h=ih/10[logo-out][video-out]

       Commands

       This filter supports the following commands:

       width, w
       height, h
           Set the output video dimension expression.  The command accepts the same syntax of the corresponding option.

           If the specified expression is not valid, it is kept at its current value.

   scale2ref_npp
       Use the NVIDIA Performance Primitives (libnpp) to scale (resize) the input video, based on a reference video.

       See the scale_npp filter for available options, scale2ref_npp supports the same but uses the reference video instead of the
       main input as basis. scale2ref_npp also supports the following additional constants for the w and h options:

       main_w
       main_h
           The main input video's width and height

       main_a
           The same as main_w / main_h

       main_sar
           The main input video's sample aspect ratio

       main_dar, mdar
           The main input video's display aspect ratio. Calculated from "(main_w / main_h) * main_sar".

       main_n
           The (sequential) number of the main input frame, starting from 0.  Only available with "eval=frame".

       main_t
           The presentation timestamp of the main input frame, expressed as a number of seconds. Only available with "eval=frame".

       main_pos
           The position (byte offset) of the frame in the main input stream, or NaN if this information is unavailable and/or
           meaningless (for example in case of synthetic video).  Only available with "eval=frame".

       Examples

       •   Scale a subtitle stream (b) to match the main video (a) in size before overlaying

                   'scale2ref_npp[b][a];[a][b]overlay_cuda'

       •   Scale a logo to 1/10th the height of a video, while preserving its display aspect ratio.

                   [logo-in][video-in]scale2ref_npp=w=oh*mdar:h=ih/10[logo-out][video-out]

   scharr
       Apply scharr operator to input video stream.

       The filter accepts the following option:

       planes
           Set which planes will be processed, unprocessed planes will be copied.  By default value 0xf, all planes will be
           processed.

       scale
           Set value which will be multiplied with filtered result.

       delta
           Set value which will be added to filtered result.

       Commands

       This filter supports the all above options as commands.

   scroll
       Scroll input video horizontally and/or vertically by constant speed.

       The filter accepts the following options:

       horizontal, h
           Set the horizontal scrolling speed. Default is 0. Allowed range is from -1 to 1.  Negative values changes scrolling
           direction.

       vertical, v
           Set the vertical scrolling speed. Default is 0. Allowed range is from -1 to 1.  Negative values changes scrolling
           direction.

       hpos
           Set the initial horizontal scrolling position. Default is 0. Allowed range is from 0 to 1.

       vpos
           Set the initial vertical scrolling position. Default is 0. Allowed range is from 0 to 1.

       Commands

       This filter supports the following commands:

       horizontal, h
           Set the horizontal scrolling speed.

       vertical, v
           Set the vertical scrolling speed.

   scdet
       Detect video scene change.

       This filter sets frame metadata with mafd between frame, the scene score, and forward the frame to the next filter, so they
       can use these metadata to detect scene change or others.

       In addition, this filter logs a message and sets frame metadata when it detects a scene change by threshold.

       "lavfi.scd.mafd" metadata keys are set with mafd for every frame.

       "lavfi.scd.score" metadata keys are set with scene change score for every frame to detect scene change.

       "lavfi.scd.time" metadata keys are set with current filtered frame time which detect scene change with threshold.

       The filter accepts the following options:

       threshold, t
           Set the scene change detection threshold as a percentage of maximum change. Good values are in the "[8.0, 14.0]" range.
           The range for threshold is "[0., 100.]".

           Default value is 10..

       sc_pass, s
           Set the flag to pass scene change frames to the next filter. Default value is 0 You can enable it if you want to get
           snapshot of scene change frames only.

   selectivecolor
       Adjust cyan, magenta, yellow and black (CMYK) to certain ranges of colors (such as "reds", "yellows", "greens", "cyans",
       ...). The adjustment range is defined by the "purity" of the color (that is, how saturated it already is).

       This filter is similar to the Adobe Photoshop Selective Color tool.

       The filter accepts the following options:

       correction_method
           Select color correction method.

           Available values are:

           absolute
               Specified adjustments are applied "as-is" (added/subtracted to original pixel component value).

           relative
               Specified adjustments are relative to the original component value.

           Default is "absolute".

       reds
           Adjustments for red pixels (pixels where the red component is the maximum)

       yellows
           Adjustments for yellow pixels (pixels where the blue component is the minimum)

       greens
           Adjustments for green pixels (pixels where the green component is the maximum)

       cyans
           Adjustments for cyan pixels (pixels where the red component is the minimum)

       blues
           Adjustments for blue pixels (pixels where the blue component is the maximum)

       magentas
           Adjustments for magenta pixels (pixels where the green component is the minimum)

       whites
           Adjustments for white pixels (pixels where all components are greater than 128)

       neutrals
           Adjustments for all pixels except pure black and pure white

       blacks
           Adjustments for black pixels (pixels where all components are lesser than 128)

       psfile
           Specify a Photoshop selective color file (".asv") to import the settings from.

       All the adjustment settings (reds, yellows, ...) accept up to 4 space separated floating point adjustment values in the
       [-1,1] range, respectively to adjust the amount of cyan, magenta, yellow and black for the pixels of its range.

       Examples

       •   Increase cyan by 50% and reduce yellow by 33% in every green areas, and increase magenta by 27% in blue areas:

                   selectivecolor=greens=.5 0 -.33 0:blues=0 .27

       •   Use a Photoshop selective color preset:

                   selectivecolor=psfile=MySelectiveColorPresets/Misty.asv

   separatefields
       The "separatefields" takes a frame-based video input and splits each frame into its components fields, producing a new half
       height clip with twice the frame rate and twice the frame count.

       This filter use field-dominance information in frame to decide which of each pair of fields to place first in the output.
       If it gets it wrong use setfield filter before "separatefields" filter.

   setdar, setsar
       The "setdar" filter sets the Display Aspect Ratio for the filter output video.

       This is done by changing the specified Sample (aka Pixel) Aspect Ratio, according to the following equation:

               <DAR> = <HORIZONTAL_RESOLUTION> / <VERTICAL_RESOLUTION> * <SAR>

       Keep in mind that the "setdar" filter does not modify the pixel dimensions of the video frame. Also, the display aspect
       ratio set by this filter may be changed by later filters in the filterchain, e.g. in case of scaling or if another "setdar"
       or a "setsar" filter is applied.

       The "setsar" filter sets the Sample (aka Pixel) Aspect Ratio for the filter output video.

       Note that as a consequence of the application of this filter, the output display aspect ratio will change according to the
       equation above.

       Keep in mind that the sample aspect ratio set by the "setsar" filter may be changed by later filters in the filterchain,
       e.g. if another "setsar" or a "setdar" filter is applied.

       It accepts the following parameters:

       r, ratio, dar ("setdar" only), sar ("setsar" only)
           Set the aspect ratio used by the filter.

           The parameter can be a floating point number string, an expression, or a string of the form num:den, where num and den
           are the numerator and denominator of the aspect ratio. If the parameter is not specified, it is assumed the value "0".
           In case the form "num:den" is used, the ":" character should be escaped.

       max Set the maximum integer value to use for expressing numerator and denominator when reducing the expressed aspect ratio
           to a rational.  Default value is 100.

       The parameter sar is an expression containing the following constants:

       E, PI, PHI
           These are approximated values for the mathematical constants e (Euler's number), pi (Greek pi), and phi (the golden
           ratio).

       w, h
           The input width and height.

       a   These are the same as w / h.

       sar The input sample aspect ratio.

       dar The input display aspect ratio. It is the same as (w / h) * sar.

       hsub, vsub
           Horizontal and vertical chroma subsample values. For example, for the pixel format "yuv422p" hsub is 2 and vsub is 1.

       Examples

       •   To change the display aspect ratio to 16:9, specify one of the following:

                   setdar=dar=1.77777
                   setdar=dar=16/9

       •   To change the sample aspect ratio to 10:11, specify:

                   setsar=sar=10/11

       •   To set a display aspect ratio of 16:9, and specify a maximum integer value of 1000 in the aspect ratio reduction, use
           the command:

                   setdar=ratio=16/9:max=1000

   setfield
       Force field for the output video frame.

       The "setfield" filter marks the interlace type field for the output frames. It does not change the input frame, but only
       sets the corresponding property, which affects how the frame is treated by following filters (e.g. "fieldorder" or "yadif").

       The filter accepts the following options:

       mode
           Available values are:

           auto
               Keep the same field property.

           bff Mark the frame as bottom-field-first.

           tff Mark the frame as top-field-first.

           prog
               Mark the frame as progressive.

   setparams
       Force frame parameter for the output video frame.

       The "setparams" filter marks interlace and color range for the output frames. It does not change the input frame, but only
       sets the corresponding property, which affects how the frame is treated by filters/encoders.

       field_mode
           Available values are:

           auto
               Keep the same field property (default).

           bff Mark the frame as bottom-field-first.

           tff Mark the frame as top-field-first.

           prog
               Mark the frame as progressive.

       range
           Available values are:

           auto
               Keep the same color range property (default).

           unspecified, unknown
               Mark the frame as unspecified color range.

           limited, tv, mpeg
               Mark the frame as limited range.

           full, pc, jpeg
               Mark the frame as full range.

       color_primaries
           Set the color primaries.  Available values are:

           auto
               Keep the same color primaries property (default).

           bt709
           unknown
           bt470m
           bt470bg
           smpte170m
           smpte240m
           film
           bt2020
           smpte428
           smpte431
           smpte432
           jedec-p22
       color_trc
           Set the color transfer.  Available values are:

           auto
               Keep the same color trc property (default).

           bt709
           unknown
           bt470m
           bt470bg
           smpte170m
           smpte240m
           linear
           log100
           log316
           iec61966-2-4
           bt1361e
           iec61966-2-1
           bt2020-10
           bt2020-12
           smpte2084
           smpte428
           arib-std-b67
       colorspace
           Set the colorspace.  Available values are:

           auto
               Keep the same colorspace property (default).

           gbr
           bt709
           unknown
           fcc
           bt470bg
           smpte170m
           smpte240m
           ycgco
           bt2020nc
           bt2020c
           smpte2085
           chroma-derived-nc
           chroma-derived-c
           ictcp

   sharpen_npp
       Use the NVIDIA Performance Primitives (libnpp) to perform image sharpening with border control.

       The following additional options are accepted:

       border_type
           Type of sampling to be used ad frame borders. One of the following:

           replicate
               Replicate pixel values.

   shear
       Apply shear transform to input video.

       This filter supports the following options:

       shx Shear factor in X-direction. Default value is 0.  Allowed range is from -2 to 2.

       shy Shear factor in Y-direction. Default value is 0.  Allowed range is from -2 to 2.

       fillcolor, c
           Set the color used to fill the output area not covered by the transformed video. For the general syntax of this option,
           check the "Color" section in the ffmpeg-utils manual.  If the special value "none" is selected then no background is
           printed (useful for example if the background is never shown).

           Default value is "black".

       interp
           Set interpolation type. Can be "bilinear" or "nearest". Default is "bilinear".

       Commands

       This filter supports the all above options as commands.

   showinfo
       Show a line containing various information for each input video frame.  The input video is not modified.

       This filter supports the following options:

       checksum
           Calculate checksums of each plane. By default enabled.

       The shown line contains a sequence of key/value pairs of the form key:value.

       The following values are shown in the output:

       n   The (sequential) number of the input frame, starting from 0.

       pts The Presentation TimeStamp of the input frame, expressed as a number of time base units. The time base unit depends on
           the filter input pad.

       pts_time
           The Presentation TimeStamp of the input frame, expressed as a number of seconds.

       pos The position of the frame in the input stream, or -1 if this information is unavailable and/or meaningless (for example
           in case of synthetic video).

       fmt The pixel format name.

       sar The sample aspect ratio of the input frame, expressed in the form num/den.

       s   The size of the input frame. For the syntax of this option, check the "Video size" section in the ffmpeg-utils manual.

       i   The type of interlaced mode ("P" for "progressive", "T" for top field first, "B" for bottom field first).

       iskey
           This is 1 if the frame is a key frame, 0 otherwise.

       type
           The picture type of the input frame ("I" for an I-frame, "P" for a P-frame, "B" for a B-frame, or "?" for an unknown
           type).  Also refer to the documentation of the "AVPictureType" enum and of the "av_get_picture_type_char" function
           defined in libavutil/avutil.h.

       checksum
           The Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame.

       plane_checksum
           The Adler-32 checksum (printed in hexadecimal) of each plane of the input frame, expressed in the form "[c0 c1 c2 c3]".

       mean
           The mean value of pixels in each plane of the input frame, expressed in the form "[mean0 mean1 mean2 mean3]".

       stdev
           The standard deviation of pixel values in each plane of the input frame, expressed in the form "[stdev0 stdev1 stdev2
           stdev3]".

   showpalette
       Displays the 256 colors palette of each frame. This filter is only relevant for pal8 pixel format frames.

       It accepts the following option:

       s   Set the size of the box used to represent one palette color entry. Default is 30 (for a "30x30" pixel box).

   shuffleframes
       Reorder and/or duplicate and/or drop video frames.

       It accepts the following parameters:

       mapping
           Set the destination indexes of input frames.  This is space or '|' separated list of indexes that maps input frames to
           output frames. Number of indexes also sets maximal value that each index may have.  '-1' index have special meaning and
           that is to drop frame.

       The first frame has the index 0. The default is to keep the input unchanged.

       Examples

       •   Swap second and third frame of every three frames of the input:

                   ffmpeg -i INPUT -vf "shuffleframes=0 2 1" OUTPUT

       •   Swap 10th and 1st frame of every ten frames of the input:

                   ffmpeg -i INPUT -vf "shuffleframes=9 1 2 3 4 5 6 7 8 0" OUTPUT

   shufflepixels
       Reorder pixels in video frames.

       This filter accepts the following options:

       direction, d
           Set shuffle direction. Can be forward or inverse direction.  Default direction is forward.

       mode, m
           Set shuffle mode. Can be horizontal, vertical or block mode.

       width, w
       height, h
           Set shuffle block_size. In case of horizontal shuffle mode only width part of size is used, and in case of vertical
           shuffle mode only height part of size is used.

       seed, s
           Set random seed used with shuffling pixels. Mainly useful to set to be able to reverse filtering process to get original
           input.  For example, to reverse forward shuffle you need to use same parameters and exact same seed and to set direction
           to inverse.

   shuffleplanes
       Reorder and/or duplicate video planes.

       It accepts the following parameters:

       map0
           The index of the input plane to be used as the first output plane.

       map1
           The index of the input plane to be used as the second output plane.

       map2
           The index of the input plane to be used as the third output plane.

       map3
           The index of the input plane to be used as the fourth output plane.

       The first plane has the index 0. The default is to keep the input unchanged.

       Examples

       •   Swap the second and third planes of the input:

                   ffmpeg -i INPUT -vf shuffleplanes=0:2:1:3 OUTPUT

   signalstats
       Evaluate various visual metrics that assist in determining issues associated with the digitization of analog video media.

       By default the filter will log these metadata values:

       YMIN
           Display the minimal Y value contained within the input frame. Expressed in range of [0-255].

       YLOW
           Display the Y value at the 10% percentile within the input frame. Expressed in range of [0-255].

       YAVG
           Display the average Y value within the input frame. Expressed in range of [0-255].

       YHIGH
           Display the Y value at the 90% percentile within the input frame. Expressed in range of [0-255].

       YMAX
           Display the maximum Y value contained within the input frame. Expressed in range of [0-255].

       UMIN
           Display the minimal U value contained within the input frame. Expressed in range of [0-255].

       ULOW
           Display the U value at the 10% percentile within the input frame. Expressed in range of [0-255].

       UAVG
           Display the average U value within the input frame. Expressed in range of [0-255].

       UHIGH
           Display the U value at the 90% percentile within the input frame. Expressed in range of [0-255].

       UMAX
           Display the maximum U value contained within the input frame. Expressed in range of [0-255].

       VMIN
           Display the minimal V value contained within the input frame. Expressed in range of [0-255].

       VLOW
           Display the V value at the 10% percentile within the input frame. Expressed in range of [0-255].

       VAVG
           Display the average V value within the input frame. Expressed in range of [0-255].

       VHIGH
           Display the V value at the 90% percentile within the input frame. Expressed in range of [0-255].

       VMAX
           Display the maximum V value contained within the input frame. Expressed in range of [0-255].

       SATMIN
           Display the minimal saturation value contained within the input frame.  Expressed in range of [0-~181.02].

       SATLOW
           Display the saturation value at the 10% percentile within the input frame.  Expressed in range of [0-~181.02].

       SATAVG
           Display the average saturation value within the input frame. Expressed in range of [0-~181.02].

       SATHIGH
           Display the saturation value at the 90% percentile within the input frame.  Expressed in range of [0-~181.02].

       SATMAX
           Display the maximum saturation value contained within the input frame.  Expressed in range of [0-~181.02].

       HUEMED
           Display the median value for hue within the input frame. Expressed in range of [0-360].

       HUEAVG
           Display the average value for hue within the input frame. Expressed in range of [0-360].

       YDIF
           Display the average of sample value difference between all values of the Y plane in the current frame and corresponding
           values of the previous input frame.  Expressed in range of [0-255].

       UDIF
           Display the average of sample value difference between all values of the U plane in the current frame and corresponding
           values of the previous input frame.  Expressed in range of [0-255].

       VDIF
           Display the average of sample value difference between all values of the V plane in the current frame and corresponding
           values of the previous input frame.  Expressed in range of [0-255].

       YBITDEPTH
           Display bit depth of Y plane in current frame.  Expressed in range of [0-16].

       UBITDEPTH
           Display bit depth of U plane in current frame.  Expressed in range of [0-16].

       VBITDEPTH
           Display bit depth of V plane in current frame.  Expressed in range of [0-16].

       The filter accepts the following options:

       stat
       out stat specify an additional form of image analysis.  out output video with the specified type of pixel highlighted.

           Both options accept the following values:

           tout
               Identify temporal outliers pixels. A temporal outlier is a pixel unlike the neighboring pixels of the same field.
               Examples of temporal outliers include the results of video dropouts, head clogs, or tape tracking issues.

           vrep
               Identify vertical line repetition. Vertical line repetition includes similar rows of pixels within a frame. In born-
               digital video vertical line repetition is common, but this pattern is uncommon in video digitized from an analog
               source. When it occurs in video that results from the digitization of an analog source it can indicate concealment
               from a dropout compensator.

           brng
               Identify pixels that fall outside of legal broadcast range.

       color, c
           Set the highlight color for the out option. The default color is yellow.

       Examples

       •   Output data of various video metrics:

                   ffprobe -f lavfi movie=example.mov,signalstats="stat=tout+vrep+brng" -show_frames

       •   Output specific data about the minimum and maximum values of the Y plane per frame:

                   ffprobe -f lavfi movie=example.mov,signalstats -show_entries frame_tags=lavfi.signalstats.YMAX,lavfi.signalstats.YMIN

       •   Playback video while highlighting pixels that are outside of broadcast range in red.

                   ffplay example.mov -vf signalstats="out=brng:color=red"

       •   Playback video with signalstats metadata drawn over the frame.

                   ffplay example.mov -vf signalstats=stat=brng+vrep+tout,drawtext=fontfile=FreeSerif.ttf:textfile=signalstat_drawtext.txt

           The contents of signalstat_drawtext.txt used in the command are:

                   time %{pts:hms}
                   Y (%{metadata:lavfi.signalstats.YMIN}-%{metadata:lavfi.signalstats.YMAX})
                   U (%{metadata:lavfi.signalstats.UMIN}-%{metadata:lavfi.signalstats.UMAX})
                   V (%{metadata:lavfi.signalstats.VMIN}-%{metadata:lavfi.signalstats.VMAX})
                   saturation maximum: %{metadata:lavfi.signalstats.SATMAX}

   signature
       Calculates the MPEG-7 Video Signature. The filter can handle more than one input. In this case the matching between the
       inputs can be calculated additionally.  The filter always passes through the first input. The signature of each stream can
       be written into a file.

       It accepts the following options:

       detectmode
           Enable or disable the matching process.

           Available values are:

           off Disable the calculation of a matching (default).

           full
               Calculate the matching for the whole video and output whether the whole video matches or only parts.

           fast
               Calculate only until a matching is found or the video ends. Should be faster in some cases.

       nb_inputs
           Set the number of inputs. The option value must be a non negative integer.  Default value is 1.

       filename
           Set the path to which the output is written. If there is more than one input, the path must be a prototype, i.e. must
           contain %d or %0nd (where n is a positive integer), that will be replaced with the input number. If no filename is
           specified, no output will be written. This is the default.

       format
           Choose the output format.

           Available values are:

           binary
               Use the specified binary representation (default).

           xml Use the specified xml representation.

       th_d
           Set threshold to detect one word as similar. The option value must be an integer greater than zero. The default value is
           9000.

       th_dc
           Set threshold to detect all words as similar. The option value must be an integer greater than zero. The default value
           is 60000.

       th_xh
           Set threshold to detect frames as similar. The option value must be an integer greater than zero. The default value is
           116.

       th_di
           Set the minimum length of a sequence in frames to recognize it as matching sequence. The option value must be a non
           negative integer value.  The default value is 0.

       th_it
           Set the minimum relation, that matching frames to all frames must have.  The option value must be a double value between
           0 and 1. The default value is 0.5.

       Examples

       •   To calculate the signature of an input video and store it in signature.bin:

                   ffmpeg -i input.mkv -vf signature=filename=signature.bin -map 0:v -f null -

       •   To detect whether two videos match and store the signatures in XML format in signature0.xml and signature1.xml:

                   ffmpeg -i input1.mkv -i input2.mkv -filter_complex "[0:v][1:v] signature=nb_inputs=2:detectmode=full:format=xml:filename=signature%d.xml" -map :v -f null -

   siti
       Calculate Spatial Info (SI) and Temporal Info (TI) scores for a video, as defined in ITU-T P.910: Subjective video quality
       assessment methods for multimedia applications. Available PDF at <https://www.itu.int/rec/T-REC-P.910-199909-S/en >.

       It accepts the following option:

       print_summary
           If set to 1, Summary statistics will be printed to the console. Default 0.

       Examples

       •   To calculate SI/TI metrics and print summary:

                   ffmpeg -i input.mp4 -vf siti=print_summary=1 -f null -

   smartblur
       Blur the input video without impacting the outlines.

       It accepts the following options:

       luma_radius, lr
           Set the luma radius. The option value must be a float number in the range [0.1,5.0] that specifies the variance of the
           gaussian filter used to blur the image (slower if larger). Default value is 1.0.

       luma_strength, ls
           Set the luma strength. The option value must be a float number in the range [-1.0,1.0] that configures the blurring. A
           value included in [0.0,1.0] will blur the image whereas a value included in [-1.0,0.0] will sharpen the image. Default
           value is 1.0.

       luma_threshold, lt
           Set the luma threshold used as a coefficient to determine whether a pixel should be blurred or not. The option value
           must be an integer in the range [-30,30]. A value of 0 will filter all the image, a value included in [0,30] will filter
           flat areas and a value included in [-30,0] will filter edges. Default value is 0.

       chroma_radius, cr
           Set the chroma radius. The option value must be a float number in the range [0.1,5.0] that specifies the variance of the
           gaussian filter used to blur the image (slower if larger). Default value is luma_radius.

       chroma_strength, cs
           Set the chroma strength. The option value must be a float number in the range [-1.0,1.0] that configures the blurring. A
           value included in [0.0,1.0] will blur the image whereas a value included in [-1.0,0.0] will sharpen the image. Default
           value is luma_strength.

       chroma_threshold, ct
           Set the chroma threshold used as a coefficient to determine whether a pixel should be blurred or not. The option value
           must be an integer in the range [-30,30]. A value of 0 will filter all the image, a value included in [0,30] will filter
           flat areas and a value included in [-30,0] will filter edges. Default value is luma_threshold.

       If a chroma option is not explicitly set, the corresponding luma value is set.

   sobel
       Apply sobel operator to input video stream.

       The filter accepts the following option:

       planes
           Set which planes will be processed, unprocessed planes will be copied.  By default value 0xf, all planes will be
           processed.

       scale
           Set value which will be multiplied with filtered result.

       delta
           Set value which will be added to filtered result.

       Commands

       This filter supports the all above options as commands.

   spp
       Apply a simple postprocessing filter that compresses and decompresses the image at several (or - in the case of quality
       level 6 - all) shifts and average the results.

       The filter accepts the following options:

       quality
           Set quality. This option defines the number of levels for averaging. It accepts an integer in the range 0-6. If set to
           0, the filter will have no effect. A value of 6 means the higher quality. For each increment of that value the speed
           drops by a factor of approximately 2.  Default value is 3.

       qp  Force a constant quantization parameter. If not set, the filter will use the QP from the video stream (if available).

       mode
           Set thresholding mode. Available modes are:

           hard
               Set hard thresholding (default).

           soft
               Set soft thresholding (better de-ringing effect, but likely blurrier).

       use_bframe_qp
           Enable the use of the QP from the B-Frames if set to 1. Using this option may cause flicker since the B-Frames have
           often larger QP. Default is 0 (not enabled).

       Commands

       This filter supports the following commands:

       quality, level
           Set quality level. The value "max" can be used to set the maximum level, currently 6.

   sr
       Scale the input by applying one of the super-resolution methods based on convolutional neural networks. Supported models:

       •   Super-Resolution Convolutional Neural Network model (SRCNN).  See <https://arxiv.org/abs/1501.00092>.

       •   Efficient Sub-Pixel Convolutional Neural Network model (ESPCN).  See <https://arxiv.org/abs/1609.05158>.

       Training scripts as well as scripts for model file (.pb) saving can be found at
       <https://github.com/XueweiMeng/sr/tree/sr_dnn_native>. Original repository is at
       <https://github.com/HighVoltageRocknRoll/sr.git>.

       Native model files (.model) can be generated from TensorFlow model files (.pb) by using tools/python/convert.py

       The filter accepts the following options:

       dnn_backend
           Specify which DNN backend to use for model loading and execution. This option accepts the following values:

           native
               Native implementation of DNN loading and execution.

           tensorflow
               TensorFlow backend. To enable this backend you need to install the TensorFlow for C library (see
               <https://www.tensorflow.org/install/lang_c>) and configure FFmpeg with "--enable-libtensorflow"

           Default value is native.

       model
           Set path to model file specifying network architecture and its parameters.  Note that different backends use different
           file formats. TensorFlow backend can load files for both formats, while native backend can load files for only its
           format.

       scale_factor
           Set scale factor for SRCNN model. Allowed values are 2, 3 and 4.  Default value is 2. Scale factor is necessary for
           SRCNN model, because it accepts input upscaled using bicubic upscaling with proper scale factor.

       To get full functionality (such as async execution), please use the dnn_processing filter.

   ssim
       Obtain the SSIM (Structural SImilarity Metric) between two input videos.

       This filter takes in input two input videos, the first input is considered the "main" source and is passed unchanged to the
       output. The second input is used as a "reference" video for computing the SSIM.

       Both video inputs must have the same resolution and pixel format for this filter to work correctly. Also it assumes that
       both inputs have the same number of frames, which are compared one by one.

       The filter stores the calculated SSIM of each frame.

       The description of the accepted parameters follows.

       stats_file, f
           If specified the filter will use the named file to save the SSIM of each individual frame. When filename equals "-" the
           data is sent to standard output.

       The file printed if stats_file is selected, contains a sequence of key/value pairs of the form key:value for each compared
       couple of frames.

       A description of each shown parameter follows:

       n   sequential number of the input frame, starting from 1

       Y, U, V, R, G, B
           SSIM of the compared frames for the component specified by the suffix.

       All SSIM of the compared frames for the whole frame.

       dB  Same as above but in dB representation.

       This filter also supports the framesync options.

       Examples

       •   For example:

                   movie=ref_movie.mpg, setpts=PTS-STARTPTS [main];
                   [main][ref] ssim="stats_file=stats.log" [out]

           On this example the input file being processed is compared with the reference file ref_movie.mpg. The SSIM of each
           individual frame is stored in stats.log.

       •   Another example with both psnr and ssim at same time:

                   ffmpeg -i main.mpg -i ref.mpg -lavfi  "ssim;[0:v][1:v]psnr" -f null -

       •   Another example with different containers:

                   ffmpeg -i main.mpg -i ref.mkv -lavfi  "[0:v]settb=AVTB,setpts=PTS-STARTPTS[main];[1:v]settb=AVTB,setpts=PTS-STARTPTS[ref];[main][ref]ssim" -f null -

   stereo3d
       Convert between different stereoscopic image formats.

       The filters accept the following options:

       in  Set stereoscopic image format of input.

           Available values for input image formats are:

           sbsl
               side by side parallel (left eye left, right eye right)

           sbsr
               side by side crosseye (right eye left, left eye right)

           sbs2l
               side by side parallel with half width resolution (left eye left, right eye right)

           sbs2r
               side by side crosseye with half width resolution (right eye left, left eye right)

           abl
           tbl above-below (left eye above, right eye below)

           abr
           tbr above-below (right eye above, left eye below)

           ab2l
           tb2l
               above-below with half height resolution (left eye above, right eye below)

           ab2r
           tb2r
               above-below with half height resolution (right eye above, left eye below)

           al  alternating frames (left eye first, right eye second)

           ar  alternating frames (right eye first, left eye second)

           irl interleaved rows (left eye has top row, right eye starts on next row)

           irr interleaved rows (right eye has top row, left eye starts on next row)

           icl interleaved columns, left eye first

           icr interleaved columns, right eye first

               Default value is sbsl.

       out Set stereoscopic image format of output.

           sbsl
               side by side parallel (left eye left, right eye right)

           sbsr
               side by side crosseye (right eye left, left eye right)

           sbs2l
               side by side parallel with half width resolution (left eye left, right eye right)

           sbs2r
               side by side crosseye with half width resolution (right eye left, left eye right)

           abl
           tbl above-below (left eye above, right eye below)

           abr
           tbr above-below (right eye above, left eye below)

           ab2l
           tb2l
               above-below with half height resolution (left eye above, right eye below)

           ab2r
           tb2r
               above-below with half height resolution (right eye above, left eye below)

           al  alternating frames (left eye first, right eye second)

           ar  alternating frames (right eye first, left eye second)

           irl interleaved rows (left eye has top row, right eye starts on next row)

           irr interleaved rows (right eye has top row, left eye starts on next row)

           arbg
               anaglyph red/blue gray (red filter on left eye, blue filter on right eye)

           argg
               anaglyph red/green gray (red filter on left eye, green filter on right eye)

           arcg
               anaglyph red/cyan gray (red filter on left eye, cyan filter on right eye)

           arch
               anaglyph red/cyan half colored (red filter on left eye, cyan filter on right eye)

           arcc
               anaglyph red/cyan color (red filter on left eye, cyan filter on right eye)

           arcd
               anaglyph red/cyan color optimized with the least squares projection of dubois (red filter on left eye, cyan filter
               on right eye)

           agmg
               anaglyph green/magenta gray (green filter on left eye, magenta filter on right eye)

           agmh
               anaglyph green/magenta half colored (green filter on left eye, magenta filter on right eye)

           agmc
               anaglyph green/magenta colored (green filter on left eye, magenta filter on right eye)

           agmd
               anaglyph green/magenta color optimized with the least squares projection of dubois (green filter on left eye,
               magenta filter on right eye)

           aybg
               anaglyph yellow/blue gray (yellow filter on left eye, blue filter on right eye)

           aybh
               anaglyph yellow/blue half colored (yellow filter on left eye, blue filter on right eye)

           aybc
               anaglyph yellow/blue colored (yellow filter on left eye, blue filter on right eye)

           aybd
               anaglyph yellow/blue color optimized with the least squares projection of dubois (yellow filter on left eye, blue
               filter on right eye)

           ml  mono output (left eye only)

           mr  mono output (right eye only)

           chl checkerboard, left eye first

           chr checkerboard, right eye first

           icl interleaved columns, left eye first

           icr interleaved columns, right eye first

           hdmi
               HDMI frame pack

           Default value is arcd.

       Examples

       •   Convert input video from side by side parallel to anaglyph yellow/blue dubois:

                   stereo3d=sbsl:aybd

       •   Convert input video from above below (left eye above, right eye below) to side by side crosseye.

                   stereo3d=abl:sbsr

   streamselect, astreamselect
       Select video or audio streams.

       The filter accepts the following options:

       inputs
           Set number of inputs. Default is 2.

       map Set input indexes to remap to outputs.

       Commands

       The "streamselect" and "astreamselect" filter supports the following commands:

       map Set input indexes to remap to outputs.

       Examples

       •   Select first 5 seconds 1st stream and rest of time 2nd stream:

                   sendcmd='5.0 streamselect map 1',streamselect=inputs=2:map=0

       •   Same as above, but for audio:

                   asendcmd='5.0 astreamselect map 1',astreamselect=inputs=2:map=0

   subtitles
       Draw subtitles on top of input video using the libass library.

       To enable compilation of this filter you need to configure FFmpeg with "--enable-libass". This filter also requires a build
       with libavcodec and libavformat to convert the passed subtitles file to ASS (Advanced Substation Alpha) subtitles format.

       The filter accepts the following options:

       filename, f
           Set the filename of the subtitle file to read. It must be specified.

       original_size
           Specify the size of the original video, the video for which the ASS file was composed. For the syntax of this option,
           check the "Video size" section in the ffmpeg-utils manual.  Due to a misdesign in ASS aspect ratio arithmetic, this is
           necessary to correctly scale the fonts if the aspect ratio has been changed.

       fontsdir
           Set a directory path containing fonts that can be used by the filter.  These fonts will be used in addition to whatever
           the font provider uses.

       alpha
           Process alpha channel, by default alpha channel is untouched.

       charenc
           Set subtitles input character encoding. "subtitles" filter only. Only useful if not UTF-8.

       stream_index, si
           Set subtitles stream index. "subtitles" filter only.

       force_style
           Override default style or script info parameters of the subtitles. It accepts a string containing ASS style format
           "KEY=VALUE" couples separated by ",".

       If the first key is not specified, it is assumed that the first value specifies the filename.

       For example, to render the file sub.srt on top of the input video, use the command:

               subtitles=sub.srt

       which is equivalent to:

               subtitles=filename=sub.srt

       To render the default subtitles stream from file video.mkv, use:

               subtitles=video.mkv

       To render the second subtitles stream from that file, use:

               subtitles=video.mkv:si=1

       To make the subtitles stream from sub.srt appear in 80% transparent blue "DejaVu Serif", use:

               subtitles=sub.srt:force_style='Fontname=DejaVu Serif,PrimaryColour=&HCCFF0000'

   super2xsai
       Scale the input by 2x and smooth using the Super2xSaI (Scale and Interpolate) pixel art scaling algorithm.

       Useful for enlarging pixel art images without reducing sharpness.

   swaprect
       Swap two rectangular objects in video.

       This filter accepts the following options:

       w   Set object width.

       h   Set object height.

       x1  Set 1st rect x coordinate.

       y1  Set 1st rect y coordinate.

       x2  Set 2nd rect x coordinate.

       y2  Set 2nd rect y coordinate.

           All expressions are evaluated once for each frame.

       The all options are expressions containing the following constants:

       w
       h   The input width and height.

       a   same as w / h

       sar input sample aspect ratio

       dar input display aspect ratio, it is the same as (w / h) * sar

       n   The number of the input frame, starting from 0.

       t   The timestamp expressed in seconds. It's NAN if the input timestamp is unknown.

       pos the position in the file of the input frame, NAN if unknown

       Commands

       This filter supports the all above options as commands.

   swapuv
       Swap U & V plane.

   tblend
       Blend successive video frames.

       See blend

   telecine
       Apply telecine process to the video.

       This filter accepts the following options:

       first_field
           top, t
               top field first

           bottom, b
               bottom field first The default value is "top".

       pattern
           A string of numbers representing the pulldown pattern you wish to apply.  The default value is 23.

               Some typical patterns:

               NTSC output (30i):
               27.5p: 32222
               24p: 23 (classic)
               24p: 2332 (preferred)
               20p: 33
               18p: 334
               16p: 3444

               PAL output (25i):
               27.5p: 12222
               24p: 222222222223 ("Euro pulldown")
               16.67p: 33
               16p: 33333334

   thistogram
       Compute and draw a color distribution histogram for the input video across time.

       Unlike histogram video filter which only shows histogram of single input frame at certain time, this filter shows also past
       histograms of number of frames defined by "width" option.

       The computed histogram is a representation of the color component distribution in an image.

       The filter accepts the following options:

       width, w
           Set width of single color component output. Default value is 0.  Value of 0 means width will be picked from input video.
           This also set number of passed histograms to keep.  Allowed range is [0, 8192].

       display_mode, d
           Set display mode.  It accepts the following values:

           stack
               Per color component graphs are placed below each other.

           parade
               Per color component graphs are placed side by side.

           overlay
               Presents information identical to that in the "parade", except that the graphs representing color components are
               superimposed directly over one another.

           Default is "stack".

       levels_mode, m
           Set mode. Can be either "linear", or "logarithmic".  Default is "linear".

       components, c
           Set what color components to display.  Default is 7.

       bgopacity, b
           Set background opacity. Default is 0.9.

       envelope, e
           Show envelope. Default is disabled.

       ecolor, ec
           Set envelope color. Default is "gold".

       slide
           Set slide mode.

           Available values for slide is:

           frame
               Draw new frame when right border is reached.

           replace
               Replace old columns with new ones.

           scroll
               Scroll from right to left.

           rscroll
               Scroll from left to right.

           picture
               Draw single picture.

           Default is "replace".

   threshold
       Apply threshold effect to video stream.

       This filter needs four video streams to perform thresholding.  First stream is stream we are filtering.  Second stream is
       holding threshold values, third stream is holding min values, and last, fourth stream is holding max values.

       The filter accepts the following option:

       planes
           Set which planes will be processed, unprocessed planes will be copied.  By default value 0xf, all planes will be
           processed.

       For example if first stream pixel's component value is less then threshold value of pixel component from 2nd threshold
       stream, third stream value will picked, otherwise fourth stream pixel component value will be picked.

       Using color source filter one can perform various types of thresholding:

       Commands

       This filter supports the all options as commands.

       Examples

       •   Binary threshold, using gray color as threshold:

                   ffmpeg -i 320x240.avi -f lavfi -i color=gray -f lavfi -i color=black -f lavfi -i color=white -lavfi threshold output.avi

       •   Inverted binary threshold, using gray color as threshold:

                   ffmpeg -i 320x240.avi -f lavfi -i color=gray -f lavfi -i color=white -f lavfi -i color=black -lavfi threshold output.avi

       •   Truncate binary threshold, using gray color as threshold:

                   ffmpeg -i 320x240.avi -f lavfi -i color=gray -i 320x240.avi -f lavfi -i color=gray -lavfi threshold output.avi

       •   Threshold to zero, using gray color as threshold:

                   ffmpeg -i 320x240.avi -f lavfi -i color=gray -f lavfi -i color=white -i 320x240.avi -lavfi threshold output.avi

       •   Inverted threshold to zero, using gray color as threshold:

                   ffmpeg -i 320x240.avi -f lavfi -i color=gray -i 320x240.avi -f lavfi -i color=white -lavfi threshold output.avi

   thumbnail
       Select the most representative frame in a given sequence of consecutive frames.

       The filter accepts the following options:

       n   Set the frames batch size to analyze; in a set of n frames, the filter will pick one of them, and then handle the next
           batch of n frames until the end. Default is 100.

       Since the filter keeps track of the whole frames sequence, a bigger n value will result in a higher memory usage, so a high
       value is not recommended.

       Examples

       •   Extract one picture each 50 frames:

                   thumbnail=50

       •   Complete example of a thumbnail creation with ffmpeg:

                   ffmpeg -i in.avi -vf thumbnail,scale=300:200 -frames:v 1 out.png

   tile
       Tile several successive frames together.

       The untile filter can do the reverse.

       The filter accepts the following options:

       layout
           Set the grid size in the form "COLUMNSxROWS". Range is upto UINT_MAX cells.  Default is "6x5".

       nb_frames
           Set the maximum number of frames to render in the given area. It must be less than or equal to wxh. The default value is
           0, meaning all the area will be used.

       margin
           Set the outer border margin in pixels. Range is 0 to 1024. Default is 0.

       padding
           Set the inner border thickness (i.e. the number of pixels between frames). For more advanced padding options (such as
           having different values for the edges), refer to the pad video filter. Range is 0 to 1024. Default is 0.

       color
           Specify the color of the unused area. For the syntax of this option, check the "Color" section in the ffmpeg-utils
           manual.  The default value of color is "black".

       overlap
           Set the number of frames to overlap when tiling several successive frames together.  The value must be between 0 and
           nb_frames - 1. Default is 0.

       init_padding
           Set the number of frames to initially be empty before displaying first output frame.  This controls how soon will one
           get first output frame.  The value must be between 0 and nb_frames - 1. Default is 0.

       Examples

       •   Produce 8x8 PNG tiles of all keyframes (-skip_frame nokey) in a movie:

                   ffmpeg -skip_frame nokey -i file.avi -vf 'scale=128:72,tile=8x8' -an -vsync 0 keyframes%03d.png

           The -vsync 0 is necessary to prevent ffmpeg from duplicating each output frame to accommodate the originally detected
           frame rate.

       •   Display 5 pictures in an area of "3x2" frames, with 7 pixels between them, and 2 pixels of initial margin, using mixed
           flat and named options:

                   tile=3x2:nb_frames=5:padding=7:margin=2

   tinterlace
       Perform various types of temporal field interlacing.

       Frames are counted starting from 1, so the first input frame is considered odd.

       The filter accepts the following options:

       mode
           Specify the mode of the interlacing. This option can also be specified as a value alone. See below for a list of values
           for this option.

           Available values are:

           merge, 0
               Move odd frames into the upper field, even into the lower field, generating a double height frame at half frame
               rate.

                        ------> time
                       Input:
                       Frame 1         Frame 2         Frame 3         Frame 4

                       11111           22222           33333           44444
                       11111           22222           33333           44444
                       11111           22222           33333           44444
                       11111           22222           33333           44444

                       Output:
                       11111                           33333
                       22222                           44444
                       11111                           33333
                       22222                           44444
                       11111                           33333
                       22222                           44444
                       11111                           33333
                       22222                           44444

           drop_even, 1
               Only output odd frames, even frames are dropped, generating a frame with unchanged height at half frame rate.

                        ------> time
                       Input:
                       Frame 1         Frame 2         Frame 3         Frame 4

                       11111           22222           33333           44444
                       11111           22222           33333           44444
                       11111           22222           33333           44444
                       11111           22222           33333           44444

                       Output:
                       11111                           33333
                       11111                           33333
                       11111                           33333
                       11111                           33333

           drop_odd, 2
               Only output even frames, odd frames are dropped, generating a frame with unchanged height at half frame rate.

                        ------> time
                       Input:
                       Frame 1         Frame 2         Frame 3         Frame 4

                       11111           22222           33333           44444
                       11111           22222           33333           44444
                       11111           22222           33333           44444
                       11111           22222           33333           44444

                       Output:
                                       22222                           44444
                                       22222                           44444
                                       22222                           44444
                                       22222                           44444

           pad, 3
               Expand each frame to full height, but pad alternate lines with black, generating a frame with double height at the
               same input frame rate.

                        ------> time
                       Input:
                       Frame 1         Frame 2         Frame 3         Frame 4

                       11111           22222           33333           44444
                       11111           22222           33333           44444
                       11111           22222           33333           44444
                       11111           22222           33333           44444

                       Output:
                       11111           .....           33333           .....
                       .....           22222           .....           44444
                       11111           .....           33333           .....
                       .....           22222           .....           44444
                       11111           .....           33333           .....
                       .....           22222           .....           44444
                       11111           .....           33333           .....
                       .....           22222           .....           44444

           interleave_top, 4
               Interleave the upper field from odd frames with the lower field from even frames, generating a frame with unchanged
               height at half frame rate.

                        ------> time
                       Input:
                       Frame 1         Frame 2         Frame 3         Frame 4

                       11111<-         22222           33333<-         44444
                       11111           22222<-         33333           44444<-
                       11111<-         22222           33333<-         44444
                       11111           22222<-         33333           44444<-

                       Output:
                       11111                           33333
                       22222                           44444
                       11111                           33333
                       22222                           44444

           interleave_bottom, 5
               Interleave the lower field from odd frames with the upper field from even frames, generating a frame with unchanged
               height at half frame rate.

                        ------> time
                       Input:
                       Frame 1         Frame 2         Frame 3         Frame 4

                       11111           22222<-         33333           44444<-
                       11111<-         22222           33333<-         44444
                       11111           22222<-         33333           44444<-
                       11111<-         22222           33333<-         44444

                       Output:
                       22222                           44444
                       11111                           33333
                       22222                           44444
                       11111                           33333

           interlacex2, 6
               Double frame rate with unchanged height. Frames are inserted each containing the second temporal field from the
               previous input frame and the first temporal field from the next input frame. This mode relies on the top_field_first
               flag. Useful for interlaced video displays with no field synchronisation.

                        ------> time
                       Input:
                       Frame 1         Frame 2         Frame 3         Frame 4

                       11111           22222           33333           44444
                        11111           22222           33333           44444
                       11111           22222           33333           44444
                        11111           22222           33333           44444

                       Output:
                       11111   22222   22222   33333   33333   44444   44444
                        11111   11111   22222   22222   33333   33333   44444
                       11111   22222   22222   33333   33333   44444   44444
                        11111   11111   22222   22222   33333   33333   44444

           mergex2, 7
               Move odd frames into the upper field, even into the lower field, generating a double height frame at same frame
               rate.

                        ------> time
                       Input:
                       Frame 1         Frame 2         Frame 3         Frame 4

                       11111           22222           33333           44444
                       11111           22222           33333           44444
                       11111           22222           33333           44444
                       11111           22222           33333           44444

                       Output:
                       11111           33333           33333           55555
                       22222           22222           44444           44444
                       11111           33333           33333           55555
                       22222           22222           44444           44444
                       11111           33333           33333           55555
                       22222           22222           44444           44444
                       11111           33333           33333           55555
                       22222           22222           44444           44444

           Numeric values are deprecated but are accepted for backward compatibility reasons.

           Default mode is "merge".

       flags
           Specify flags influencing the filter process.

           Available value for flags is:

           low_pass_filter, vlpf
               Enable linear vertical low-pass filtering in the filter.  Vertical low-pass filtering is required when creating an
               interlaced destination from a progressive source which contains high-frequency vertical detail. Filtering will
               reduce interlace 'twitter' and Moire patterning.

           complex_filter, cvlpf
               Enable complex vertical low-pass filtering.  This will slightly less reduce interlace 'twitter' and Moire patterning
               but better retain detail and subjective sharpness impression.

           bypass_il
               Bypass already interlaced frames, only adjust the frame rate.

           Vertical low-pass filtering and bypassing already interlaced frames can only be enabled for mode interleave_top and
           interleave_bottom.

   tmedian
       Pick median pixels from several successive input video frames.

       The filter accepts the following options:

       radius
           Set radius of median filter.  Default is 1. Allowed range is from 1 to 127.

       planes
           Set which planes to filter. Default value is 15, by which all planes are processed.

       percentile
           Set median percentile. Default value is 0.5.  Default value of 0.5 will pick always median values, while 0 will pick
           minimum values, and 1 maximum values.

       Commands

       This filter supports all above options as commands, excluding option "radius".

   tmidequalizer
       Apply Temporal Midway Video Equalization effect.

       Midway Video Equalization adjusts a sequence of video frames to have the same histograms, while maintaining their dynamics
       as much as possible. It's useful for e.g. matching exposures from a video frames sequence.

       This filter accepts the following option:

       radius
           Set filtering radius. Default is 5. Allowed range is from 1 to 127.

       sigma
           Set filtering sigma. Default is 0.5. This controls strength of filtering.  Setting this option to 0 effectively does
           nothing.

       planes
           Set which planes to process. Default is 15, which is all available planes.

   tmix
       Mix successive video frames.

       A description of the accepted options follows.

       frames
           The number of successive frames to mix. If unspecified, it defaults to 3.

       weights
           Specify weight of each input video frame.  Each weight is separated by space. If number of weights is smaller than
           number of frames last specified weight will be used for all remaining unset weights.

       scale
           Specify scale, if it is set it will be multiplied with sum of each weight multiplied with pixel values to give final
           destination pixel value. By default scale is auto scaled to sum of weights.

       planes
           Set which planes to filter. Default is all. Allowed range is from 0 to 15.

       Examples

       •   Average 7 successive frames:

                   tmix=frames=7:weights="1 1 1 1 1 1 1"

       •   Apply simple temporal convolution:

                   tmix=frames=3:weights="-1 3 -1"

       •   Similar as above but only showing temporal differences:

                   tmix=frames=3:weights="-1 2 -1":scale=1

       Commands

       This filter supports the following commands:

       weights
       scale
       planes
           Syntax is same as option with same name.

   tonemap
       Tone map colors from different dynamic ranges.

       This filter expects data in single precision floating point, as it needs to operate on (and can output) out-of-range values.
       Another filter, such as zscale, is needed to convert the resulting frame to a usable format.

       The tonemapping algorithms implemented only work on linear light, so input data should be linearized beforehand (and
       possibly correctly tagged).

               ffmpeg -i INPUT -vf zscale=transfer=linear,tonemap=clip,zscale=transfer=bt709,format=yuv420p OUTPUT

       Options

       The filter accepts the following options.

       tonemap
           Set the tone map algorithm to use.

           Possible values are:

           none
               Do not apply any tone map, only desaturate overbright pixels.

           clip
               Hard-clip any out-of-range values. Use it for perfect color accuracy for in-range values, while distorting out-of-
               range values.

           linear
               Stretch the entire reference gamut to a linear multiple of the display.

           gamma
               Fit a logarithmic transfer between the tone curves.

           reinhard
               Preserve overall image brightness with a simple curve, using nonlinear contrast, which results in flattening details
               and degrading color accuracy.

           hable
               Preserve both dark and bright details better than reinhard, at the cost of slightly darkening everything. Use it
               when detail preservation is more important than color and brightness accuracy.

           mobius
               Smoothly map out-of-range values, while retaining contrast and colors for in-range material as much as possible. Use
               it when color accuracy is more important than detail preservation.

           Default is none.

       param
           Tune the tone mapping algorithm.

           This affects the following algorithms:

           none
               Ignored.

           linear
               Specifies the scale factor to use while stretching.  Default to 1.0.

           gamma
               Specifies the exponent of the function.  Default to 1.8.

           clip
               Specify an extra linear coefficient to multiply into the signal before clipping.  Default to 1.0.

           reinhard
               Specify the local contrast coefficient at the display peak.  Default to 0.5, which means that in-gamut values will
               be about half as bright as when clipping.

           hable
               Ignored.

           mobius
               Specify the transition point from linear to mobius transform. Every value below this point is guaranteed to be
               mapped 1:1. The higher the value, the more accurate the result will be, at the cost of losing bright details.
               Default to 0.3, which due to the steep initial slope still preserves in-range colors fairly accurately.

       desat
           Apply desaturation for highlights that exceed this level of brightness. The higher the parameter, the more color
           information will be preserved. This setting helps prevent unnaturally blown-out colors for super-highlights, by
           (smoothly) turning into white instead. This makes images feel more natural, at the cost of reducing information about
           out-of-range colors.

           The default of 2.0 is somewhat conservative and will mostly just apply to skies or directly sunlit surfaces. A setting
           of 0.0 disables this option.

           This option works only if the input frame has a supported color tag.

       peak
           Override signal/nominal/reference peak with this value. Useful when the embedded peak information in display metadata is
           not reliable or when tone mapping from a lower range to a higher range.

   tpad
       Temporarily pad video frames.

       The filter accepts the following options:

       start
           Specify number of delay frames before input video stream. Default is 0.

       stop
           Specify number of padding frames after input video stream.  Set to -1 to pad indefinitely. Default is 0.

       start_mode
           Set kind of frames added to beginning of stream.  Can be either add or clone.  With add frames of solid-color are added.
           With clone frames are clones of first frame.  Default is add.

       stop_mode
           Set kind of frames added to end of stream.  Can be either add or clone.  With add frames of solid-color are added.  With
           clone frames are clones of last frame.  Default is add.

       start_duration, stop_duration
           Specify the duration of the start/stop delay. See the Time duration section in the ffmpeg-utils(1) manual for the
           accepted syntax.  These options override start and stop. Default is 0.

       color
           Specify the color of the padded area. For the syntax of this option, check the "Color" section in the ffmpeg-utils
           manual.

           The default value of color is "black".

   transpose
       Transpose rows with columns in the input video and optionally flip it.

       It accepts the following parameters:

       dir Specify the transposition direction.

           Can assume the following values:

           0, 4, cclock_flip
               Rotate by 90 degrees counterclockwise and vertically flip (default), that is:

                       L.R     L.l
                       . . ->  . .
                       l.r     R.r

           1, 5, clock
               Rotate by 90 degrees clockwise, that is:

                       L.R     l.L
                       . . ->  . .
                       l.r     r.R

           2, 6, cclock
               Rotate by 90 degrees counterclockwise, that is:

                       L.R     R.r
                       . . ->  . .
                       l.r     L.l

           3, 7, clock_flip
               Rotate by 90 degrees clockwise and vertically flip, that is:

                       L.R     r.R
                       . . ->  . .
                       l.r     l.L

           For values between 4-7, the transposition is only done if the input video geometry is portrait and not landscape. These
           values are deprecated, the "passthrough" option should be used instead.

           Numerical values are deprecated, and should be dropped in favor of symbolic constants.

       passthrough
           Do not apply the transposition if the input geometry matches the one specified by the specified value. It accepts the
           following values:

           none
               Always apply transposition.

           portrait
               Preserve portrait geometry (when height >= width).

           landscape
               Preserve landscape geometry (when width >= height).

           Default value is "none".

       For example to rotate by 90 degrees clockwise and preserve portrait layout:

               transpose=dir=1:passthrough=portrait

       The command above can also be specified as:

               transpose=1:portrait

   transpose_npp
       Transpose rows with columns in the input video and optionally flip it.  For more in depth examples see the transpose video
       filter, which shares mostly the same options.

       It accepts the following parameters:

       dir Specify the transposition direction.

           Can assume the following values:

           cclock_flip
               Rotate by 90 degrees counterclockwise and vertically flip. (default)

           clock
               Rotate by 90 degrees clockwise.

           cclock
               Rotate by 90 degrees counterclockwise.

           clock_flip
               Rotate by 90 degrees clockwise and vertically flip.

       passthrough
           Do not apply the transposition if the input geometry matches the one specified by the specified value. It accepts the
           following values:

           none
               Always apply transposition. (default)

           portrait
               Preserve portrait geometry (when height >= width).

           landscape
               Preserve landscape geometry (when width >= height).

   trim
       Trim the input so that the output contains one continuous subpart of the input.

       It accepts the following parameters:

       start
           Specify the time of the start of the kept section, i.e. the frame with the timestamp start will be the first frame in
           the output.

       end Specify the time of the first frame that will be dropped, i.e. the frame immediately preceding the one with the
           timestamp end will be the last frame in the output.

       start_pts
           This is the same as start, except this option sets the start timestamp in timebase units instead of seconds.

       end_pts
           This is the same as end, except this option sets the end timestamp in timebase units instead of seconds.

       duration
           The maximum duration of the output in seconds.

       start_frame
           The number of the first frame that should be passed to the output.

       end_frame
           The number of the first frame that should be dropped.

       start, end, and duration are expressed as time duration specifications; see the Time duration section in the ffmpeg-utils(1)
       manual for the accepted syntax.

       Note that the first two sets of the start/end options and the duration option look at the frame timestamp, while the _frame
       variants simply count the frames that pass through the filter. Also note that this filter does not modify the timestamps. If
       you wish for the output timestamps to start at zero, insert a setpts filter after the trim filter.

       If multiple start or end options are set, this filter tries to be greedy and keep all the frames that match at least one of
       the specified constraints. To keep only the part that matches all the constraints at once, chain multiple trim filters.

       The defaults are such that all the input is kept. So it is possible to set e.g.  just the end values to keep everything
       before the specified time.

       Examples:

       •   Drop everything except the second minute of input:

                   ffmpeg -i INPUT -vf trim=60:120

       •   Keep only the first second:

                   ffmpeg -i INPUT -vf trim=duration=1

   unpremultiply
       Apply alpha unpremultiply effect to input video stream using first plane of second stream as alpha.

       Both streams must have same dimensions and same pixel format.

       The filter accepts the following option:

       planes
           Set which planes will be processed, unprocessed planes will be copied.  By default value 0xf, all planes will be
           processed.

           If the format has 1 or 2 components, then luma is bit 0.  If the format has 3 or 4 components: for RGB formats bit 0 is
           green, bit 1 is blue and bit 2 is red; for YUV formats bit 0 is luma, bit 1 is chroma-U and bit 2 is chroma-V.  If
           present, the alpha channel is always the last bit.

       inplace
           Do not require 2nd input for processing, instead use alpha plane from input stream.

   unsharp
       Sharpen or blur the input video.

       It accepts the following parameters:

       luma_msize_x, lx
           Set the luma matrix horizontal size. It must be an odd integer between 3 and 23. The default value is 5.

       luma_msize_y, ly
           Set the luma matrix vertical size. It must be an odd integer between 3 and 23. The default value is 5.

       luma_amount, la
           Set the luma effect strength. It must be a floating point number, reasonable values lay between -1.5 and 1.5.

           Negative values will blur the input video, while positive values will sharpen it, a value of zero will disable the
           effect.

           Default value is 1.0.

       chroma_msize_x, cx
           Set the chroma matrix horizontal size. It must be an odd integer between 3 and 23. The default value is 5.

       chroma_msize_y, cy
           Set the chroma matrix vertical size. It must be an odd integer between 3 and 23. The default value is 5.

       chroma_amount, ca
           Set the chroma effect strength. It must be a floating point number, reasonable values lay between -1.5 and 1.5.

           Negative values will blur the input video, while positive values will sharpen it, a value of zero will disable the
           effect.

           Default value is 0.0.

       alpha_msize_x, ax
           Set the alpha matrix horizontal size. It must be an odd integer between 3 and 23. The default value is 5.

       alpha_msize_y, ay
           Set the alpha matrix vertical size. It must be an odd integer between 3 and 23. The default value is 5.

       alpha_amount, aa
           Set the alpha effect strength. It must be a floating point number, reasonable values lay between -1.5 and 1.5.

           Negative values will blur the input video, while positive values will sharpen it, a value of zero will disable the
           effect.

           Default value is 0.0.

       All parameters are optional and default to the equivalent of the string '5:5:1.0:5:5:0.0'.

       Examples

       •   Apply strong luma sharpen effect:

                   unsharp=luma_msize_x=7:luma_msize_y=7:luma_amount=2.5

       •   Apply a strong blur of both luma and chroma parameters:

                   unsharp=7:7:-2:7:7:-2

   untile
       Decompose a video made of tiled images into the individual images.

       The frame rate of the output video is the frame rate of the input video multiplied by the number of tiles.

       This filter does the reverse of tile.

       The filter accepts the following options:

       layout
           Set the grid size (i.e. the number of lines and columns). For the syntax of this option, check the "Video size" section
           in the ffmpeg-utils manual.

       Examples

       •   Produce a 1-second video from a still image file made of 25 frames stacked vertically, like an analogic film reel:

                   ffmpeg -r 1 -i image.jpg -vf untile=1x25 movie.mkv

   uspp
       Apply ultra slow/simple postprocessing filter that compresses and decompresses the image at several (or - in the case of
       quality level 8 - all) shifts and average the results.

       The way this differs from the behavior of spp is that uspp actually encodes & decodes each case with libavcodec Snow,
       whereas spp uses a simplified intra only 8x8 DCT similar to MJPEG.

       This filter is only available in ffmpeg version 4.4 or earlier.

       The filter accepts the following options:

       quality
           Set quality. This option defines the number of levels for averaging. It accepts an integer in the range 0-8. If set to
           0, the filter will have no effect. A value of 8 means the higher quality. For each increment of that value the speed
           drops by a factor of approximately 2.  Default value is 3.

       qp  Force a constant quantization parameter. If not set, the filter will use the QP from the video stream (if available).

   v360
       Convert 360 videos between various formats.

       The filter accepts the following options:

       input
       output
           Set format of the input/output video.

           Available formats:

           e
           equirect
               Equirectangular projection.

           c3x2
           c6x1
           c1x6
               Cubemap with 3x2/6x1/1x6 layout.

               Format specific options:

               in_pad
               out_pad
                   Set padding proportion for the input/output cubemap. Values in decimals.

                   Example values:

                   0   No padding.

                   0.01
                       1% of face is padding. For example, with 1920x1280 resolution face size would be 640x640 and padding would
                       be 3 pixels from each side. (640 * 0.01 = 6 pixels)

                   Default value is @samp{0}.  Maximum value is @samp{0.1}.

               fin_pad
               fout_pad
                   Set fixed padding for the input/output cubemap. Values in pixels.

                   Default value is @samp{0}. If greater than zero it overrides other padding options.

               in_forder
               out_forder
                   Set order of faces for the input/output cubemap. Choose one direction for each position.

                   Designation of directions:

                   r   right

                   l   left

                   u   up

                   d   down

                   f   forward

                   b   back

                   Default value is @samp{rludfb}.

               in_frot
               out_frot
                   Set rotation of faces for the input/output cubemap. Choose one angle for each position.

                   Designation of angles:

                   0   0 degrees clockwise

                   1   90 degrees clockwise

                   2   180 degrees clockwise

                   3   270 degrees clockwise

                   Default value is @samp{000000}.

           eac Equi-Angular Cubemap.

           flat
           gnomonic
           rectilinear
               Regular video.

               Format specific options:

               h_fov
               v_fov
               d_fov
                   Set output horizontal/vertical/diagonal field of view. Values in degrees.

                   If diagonal field of view is set it overrides horizontal and vertical field of view.

               ih_fov
               iv_fov
               id_fov
                   Set input horizontal/vertical/diagonal field of view. Values in degrees.

                   If diagonal field of view is set it overrides horizontal and vertical field of view.

           dfisheye
               Dual fisheye.

               Format specific options:

               h_fov
               v_fov
               d_fov
                   Set output horizontal/vertical/diagonal field of view. Values in degrees.

                   If diagonal field of view is set it overrides horizontal and vertical field of view.

               ih_fov
               iv_fov
               id_fov
                   Set input horizontal/vertical/diagonal field of view. Values in degrees.

                   If diagonal field of view is set it overrides horizontal and vertical field of view.

           barrel
           fb
           barrelsplit
               Facebook's 360 formats.

           sg  Stereographic format.

               Format specific options:

               h_fov
               v_fov
               d_fov
                   Set output horizontal/vertical/diagonal field of view. Values in degrees.

                   If diagonal field of view is set it overrides horizontal and vertical field of view.

               ih_fov
               iv_fov
               id_fov
                   Set input horizontal/vertical/diagonal field of view. Values in degrees.

                   If diagonal field of view is set it overrides horizontal and vertical field of view.

           mercator
               Mercator format.

           ball
               Ball format, gives significant distortion toward the back.

           hammer
               Hammer-Aitoff map projection format.

           sinusoidal
               Sinusoidal map projection format.

           fisheye
               Fisheye projection.

               Format specific options:

               h_fov
               v_fov
               d_fov
                   Set output horizontal/vertical/diagonal field of view. Values in degrees.

                   If diagonal field of view is set it overrides horizontal and vertical field of view.

               ih_fov
               iv_fov
               id_fov
                   Set input horizontal/vertical/diagonal field of view. Values in degrees.

                   If diagonal field of view is set it overrides horizontal and vertical field of view.

           pannini
               Pannini projection.

               Format specific options:

               h_fov
                   Set output pannini parameter.

               ih_fov
                   Set input pannini parameter.

           cylindrical
               Cylindrical projection.

               Format specific options:

               h_fov
               v_fov
               d_fov
                   Set output horizontal/vertical/diagonal field of view. Values in degrees.

                   If diagonal field of view is set it overrides horizontal and vertical field of view.

               ih_fov
               iv_fov
               id_fov
                   Set input horizontal/vertical/diagonal field of view. Values in degrees.

                   If diagonal field of view is set it overrides horizontal and vertical field of view.

           perspective
               Perspective projection. (output only)

               Format specific options:

               v_fov
                   Set perspective parameter.

           tetrahedron
               Tetrahedron projection.

           tsp Truncated square pyramid projection.

           he
           hequirect
               Half equirectangular projection.

           equisolid
               Equisolid format.

               Format specific options:

               h_fov
               v_fov
               d_fov
                   Set output horizontal/vertical/diagonal field of view. Values in degrees.

                   If diagonal field of view is set it overrides horizontal and vertical field of view.

               ih_fov
               iv_fov
               id_fov
                   Set input horizontal/vertical/diagonal field of view. Values in degrees.

                   If diagonal field of view is set it overrides horizontal and vertical field of view.

           og  Orthographic format.

               Format specific options:

               h_fov
               v_fov
               d_fov
                   Set output horizontal/vertical/diagonal field of view. Values in degrees.

                   If diagonal field of view is set it overrides horizontal and vertical field of view.

               ih_fov
               iv_fov
               id_fov
                   Set input horizontal/vertical/diagonal field of view. Values in degrees.

                   If diagonal field of view is set it overrides horizontal and vertical field of view.

           octahedron
               Octahedron projection.

           cylindricalea
               Cylindrical Equal Area projection.

       interp
           Set interpolation method.Note: more complex interpolation methods require much more memory to run.

           Available methods:

           near
           nearest
               Nearest neighbour.

           line
           linear
               Bilinear interpolation.

           lagrange9
               Lagrange9 interpolation.

           cube
           cubic
               Bicubic interpolation.

           lanc
           lanczos
               Lanczos interpolation.

           sp16
           spline16
               Spline16 interpolation.

           gauss
           gaussian
               Gaussian interpolation.

           mitchell
               Mitchell interpolation.

           Default value is @samp{line}.

       w
       h   Set the output video resolution.

           Default resolution depends on formats.

       in_stereo
       out_stereo
           Set the input/output stereo format.

           2d  2D mono

           sbs Side by side

           tb  Top bottom

           Default value is @samp{2d} for input and output format.

       yaw
       pitch
       roll
           Set rotation for the output video. Values in degrees.

       rorder
           Set rotation order for the output video. Choose one item for each position.

           y, Y
               yaw

           p, P
               pitch

           r, R
               roll

           Default value is @samp{ypr}.

       h_flip
       v_flip
       d_flip
           Flip the output video horizontally(swaps left-right)/vertically(swaps up-down)/in-depth(swaps back-forward). Boolean
           values.

       ih_flip
       iv_flip
           Set if input video is flipped horizontally/vertically. Boolean values.

       in_trans
           Set if input video is transposed. Boolean value, by default disabled.

       out_trans
           Set if output video needs to be transposed. Boolean value, by default disabled.

       h_offset
       v_offset
           Set output horizontal/vertical off-axis offset. Default is set to 0.  Allowed range is from -1 to 1.

       alpha_mask
           Build mask in alpha plane for all unmapped pixels by marking them fully transparent. Boolean value, by default disabled.

       reset_rot
           Reset rotation of output video. Boolean value, by default disabled.

       Examples

       •   Convert equirectangular video to cubemap with 3x2 layout and 1% padding using bicubic interpolation:

                   ffmpeg -i input.mkv -vf v360=e:c3x2:cubic:out_pad=0.01 output.mkv

       •   Extract back view of Equi-Angular Cubemap:

                   ffmpeg -i input.mkv -vf v360=eac:flat:yaw=180 output.mkv

       •   Convert transposed and horizontally flipped Equi-Angular Cubemap in side-by-side stereo format to equirectangular top-
           bottom stereo format:

                   v360=eac:equirect:in_stereo=sbs:in_trans=1:ih_flip=1:out_stereo=tb

       Commands

       This filter supports subset of above options as commands.

   vaguedenoiser
       Apply a wavelet based denoiser.

       It transforms each frame from the video input into the wavelet domain, using Cohen-Daubechies-Feauveau 9/7. Then it applies
       some filtering to the obtained coefficients. It does an inverse wavelet transform after.  Due to wavelet properties, it
       should give a nice smoothed result, and reduced noise, without blurring picture features.

       This filter accepts the following options:

       threshold
           The filtering strength. The higher, the more filtered the video will be.  Hard thresholding can use a higher threshold
           than soft thresholding before the video looks overfiltered. Default value is 2.

       method
           The filtering method the filter will use.

           It accepts the following values:

           hard
               All values under the threshold will be zeroed.

           soft
               All values under the threshold will be zeroed. All values above will be reduced by the threshold.

           garrote
               Scales or nullifies coefficients - intermediary between (more) soft and (less) hard thresholding.

           Default is garrote.

       nsteps
           Number of times, the wavelet will decompose the picture. Picture can't be decomposed beyond a particular point
           (typically, 8 for a 640x480 frame - as 2^9 = 512 > 480). Valid values are integers between 1 and 32. Default value is 6.

       percent
           Partial of full denoising (limited coefficients shrinking), from 0 to 100. Default value is 85.

       planes
           A list of the planes to process. By default all planes are processed.

       type
           The threshold type the filter will use.

           It accepts the following values:

           universal
               Threshold used is same for all decompositions.

           bayes
               Threshold used depends also on each decomposition coefficients.

           Default is universal.

   varblur
       Apply variable blur filter by using 2nd video stream to set blur radius.  The 2nd stream must have the same dimensions.

       This filter accepts the following options:

       min_r
           Set min allowed radius. Allowed range is from 0 to 254. Default is 0.

       max_r
           Set max allowed radius. Allowed range is from 1 to 255. Default is 8.

       planes
           Set which planes to process. By default, all are used.

       The "varblur" filter also supports the framesync options.

       Commands

       This filter supports all the above options as commands.

   vectorscope
       Display 2 color component values in the two dimensional graph (which is called a vectorscope).

       This filter accepts the following options:

       mode, m
           Set vectorscope mode.

           It accepts the following values:

           gray
           tint
               Gray values are displayed on graph, higher brightness means more pixels have same component color value on location
               in graph. This is the default mode.

           color
               Gray values are displayed on graph. Surrounding pixels values which are not present in video frame are drawn in
               gradient of 2 color components which are set by option "x" and "y". The 3rd color component is static.

           color2
               Actual color components values present in video frame are displayed on graph.

           color3
               Similar as color2 but higher frequency of same values "x" and "y" on graph increases value of another color
               component, which is luminance by default values of "x" and "y".

           color4
               Actual colors present in video frame are displayed on graph. If two different colors map to same position on graph
               then color with higher value of component not present in graph is picked.

           color5
               Gray values are displayed on graph. Similar to "color" but with 3rd color component picked from radial gradient.

       x   Set which color component will be represented on X-axis. Default is 1.

       y   Set which color component will be represented on Y-axis. Default is 2.

       intensity, i
           Set intensity, used by modes: gray, color, color3 and color5 for increasing brightness of color component which
           represents frequency of (X, Y) location in graph.

       envelope, e
           none
               No envelope, this is default.

           instant
               Instant envelope, even darkest single pixel will be clearly highlighted.

           peak
               Hold maximum and minimum values presented in graph over time. This way you can still spot out of range values
               without constantly looking at vectorscope.

           peak+instant
               Peak and instant envelope combined together.

       graticule, g
           Set what kind of graticule to draw.

           none
           green
           color
           invert
       opacity, o
           Set graticule opacity.

       flags, f
           Set graticule flags.

           white
               Draw graticule for white point.

           black
               Draw graticule for black point.

           name
               Draw color points short names.

       bgopacity, b
           Set background opacity.

       lthreshold, l
           Set low threshold for color component not represented on X or Y axis.  Values lower than this value will be ignored.
           Default is 0.  Note this value is multiplied with actual max possible value one pixel component can have. So for 8-bit
           input and low threshold value of 0.1 actual threshold is 0.1 * 255 = 25.

       hthreshold, h
           Set high threshold for color component not represented on X or Y axis.  Values higher than this value will be ignored.
           Default is 1.  Note this value is multiplied with actual max possible value one pixel component can have. So for 8-bit
           input and high threshold value of 0.9 actual threshold is 0.9 * 255 = 230.

       colorspace, c
           Set what kind of colorspace to use when drawing graticule.

           auto
           601
           709

           Default is auto.

       tint0, t0
       tint1, t1
           Set color tint for gray/tint vectorscope mode. By default both options are zero.  This means no tint, and output will
           remain gray.

   vidstabdetect
       Analyze video stabilization/deshaking. Perform pass 1 of 2, see vidstabtransform for pass 2.

       This filter generates a file with relative translation and rotation transform information about subsequent frames, which is
       then used by the vidstabtransform filter.

       To enable compilation of this filter you need to configure FFmpeg with "--enable-libvidstab".

       This filter accepts the following options:

       result
           Set the path to the file used to write the transforms information.  Default value is transforms.trf.

       shakiness
           Set how shaky the video is and how quick the camera is. It accepts an integer in the range 1-10, a value of 1 means
           little shakiness, a value of 10 means strong shakiness. Default value is 5.

       accuracy
           Set the accuracy of the detection process. It must be a value in the range 1-15. A value of 1 means low accuracy, a
           value of 15 means high accuracy. Default value is 15.

       stepsize
           Set stepsize of the search process. The region around minimum is scanned with 1 pixel resolution. Default value is 6.

       mincontrast
           Set minimum contrast. Below this value a local measurement field is discarded. Must be a floating point value in the
           range 0-1. Default value is 0.3.

       tripod
           Set reference frame number for tripod mode.

           If enabled, the motion of the frames is compared to a reference frame in the filtered stream, identified by the
           specified number. The idea is to compensate all movements in a more-or-less static scene and keep the camera view
           absolutely still.

           If set to 0, it is disabled. The frames are counted starting from 1.

       show
           Show fields and transforms in the resulting frames. It accepts an integer in the range 0-2. Default value is 0, which
           disables any visualization.

       Examples

       •   Use default values:

                   vidstabdetect

       •   Analyze strongly shaky movie and put the results in file mytransforms.trf:

                   vidstabdetect=shakiness=10:accuracy=15:result="mytransforms.trf"

       •   Visualize the result of internal transformations in the resulting video:

                   vidstabdetect=show=1

       •   Analyze a video with medium shakiness using ffmpeg:

                   ffmpeg -i input -vf vidstabdetect=shakiness=5:show=1 dummy.avi

   vidstabtransform
       Video stabilization/deshaking: pass 2 of 2, see vidstabdetect for pass 1.

       Read a file with transform information for each frame and apply/compensate them. Together with the vidstabdetect filter this
       can be used to deshake videos. See also <http://public.hronopik.de/vid.stab>. It is important to also use the unsharp
       filter, see below.

       To enable compilation of this filter you need to configure FFmpeg with "--enable-libvidstab".

       Options

       input
           Set path to the file used to read the transforms. Default value is transforms.trf.

       smoothing
           Set the number of frames (value*2 + 1) used for lowpass filtering the camera movements. Default value is 10.

           For example a number of 10 means that 21 frames are used (10 in the past and 10 in the future) to smoothen the motion in
           the video. A larger value leads to a smoother video, but limits the acceleration of the camera (pan/tilt movements). 0
           is a special case where a static camera is simulated.

       optalgo
           Set the camera path optimization algorithm.

           Accepted values are:

           gauss
               gaussian kernel low-pass filter on camera motion (default)

           avg averaging on transformations

       maxshift
           Set maximal number of pixels to translate frames. Default value is -1, meaning no limit.

       maxangle
           Set maximal angle in radians (degree*PI/180) to rotate frames. Default value is -1, meaning no limit.

       crop
           Specify how to deal with borders that may be visible due to movement compensation.

           Available values are:

           keep
               keep image information from previous frame (default)

           black
               fill the border black

       invert
           Invert transforms if set to 1. Default value is 0.

       relative
           Consider transforms as relative to previous frame if set to 1, absolute if set to 0. Default value is 0.

       zoom
           Set percentage to zoom. A positive value will result in a zoom-in effect, a negative value in a zoom-out effect. Default
           value is 0 (no zoom).

       optzoom
           Set optimal zooming to avoid borders.

           Accepted values are:

           0   disabled

           1   optimal static zoom value is determined (only very strong movements will lead to visible borders) (default)

           2   optimal adaptive zoom value is determined (no borders will be visible), see zoomspeed

           Note that the value given at zoom is added to the one calculated here.

       zoomspeed
           Set percent to zoom maximally each frame (enabled when optzoom is set to 2). Range is from 0 to 5, default value is
           0.25.

       interpol
           Specify type of interpolation.

           Available values are:

           no  no interpolation

           linear
               linear only horizontal

           bilinear
               linear in both directions (default)

           bicubic
               cubic in both directions (slow)

       tripod
           Enable virtual tripod mode if set to 1, which is equivalent to "relative=0:smoothing=0". Default value is 0.

           Use also "tripod" option of vidstabdetect.

       debug
           Increase log verbosity if set to 1. Also the detected global motions are written to the temporary file
           global_motions.trf. Default value is 0.

       Examples

       •   Use ffmpeg for a typical stabilization with default values:

                   ffmpeg -i inp.mpeg -vf vidstabtransform,unsharp=5:5:0.8:3:3:0.4 inp_stabilized.mpeg

           Note the use of the unsharp filter which is always recommended.

       •   Zoom in a bit more and load transform data from a given file:

                   vidstabtransform=zoom=5:input="mytransforms.trf"

       •   Smoothen the video even more:

                   vidstabtransform=smoothing=30

   vflip
       Flip the input video vertically.

       For example, to vertically flip a video with ffmpeg:

               ffmpeg -i in.avi -vf "vflip" out.avi

   vfrdet
       Detect variable frame rate video.

       This filter tries to detect if the input is variable or constant frame rate.

       At end it will output number of frames detected as having variable delta pts, and ones with constant delta pts.  If there
       was frames with variable delta, than it will also show min, max and average delta encountered.

   vibrance
       Boost or alter saturation.

       The filter accepts the following options:

       intensity
           Set strength of boost if positive value or strength of alter if negative value.  Default is 0. Allowed range is from -2
           to 2.

       rbal
           Set the red balance. Default is 1. Allowed range is from -10 to 10.

       gbal
           Set the green balance. Default is 1. Allowed range is from -10 to 10.

       bbal
           Set the blue balance. Default is 1. Allowed range is from -10 to 10.

       rlum
           Set the red luma coefficient.

       glum
           Set the green luma coefficient.

       blum
           Set the blue luma coefficient.

       alternate
           If "intensity" is negative and this is set to 1, colors will change, otherwise colors will be less saturated, more
           towards gray.

       Commands

       This filter supports the all above options as commands.

   vif
       Obtain the average VIF (Visual Information Fidelity) between two input videos.

       This filter takes two input videos.

       Both input videos must have the same resolution and pixel format for this filter to work correctly. Also it assumes that
       both inputs have the same number of frames, which are compared one by one.

       The obtained average VIF score is printed through the logging system.

       The filter stores the calculated VIF score of each frame.

       In the below example the input file main.mpg being processed is compared with the reference file ref.mpg.

               ffmpeg -i main.mpg -i ref.mpg -lavfi vif -f null -

   vignette
       Make or reverse a natural vignetting effect.

       The filter accepts the following options:

       angle, a
           Set lens angle expression as a number of radians.

           The value is clipped in the "[0,PI/2]" range.

           Default value: "PI/5"

       x0
       y0  Set center coordinates expressions. Respectively "w/2" and "h/2" by default.

       mode
           Set forward/backward mode.

           Available modes are:

           forward
               The larger the distance from the central point, the darker the image becomes.

           backward
               The larger the distance from the central point, the brighter the image becomes.  This can be used to reverse a
               vignette effect, though there is no automatic detection to extract the lens angle and other settings (yet). It can
               also be used to create a burning effect.

           Default value is forward.

       eval
           Set evaluation mode for the expressions (angle, x0, y0).

           It accepts the following values:

           init
               Evaluate expressions only once during the filter initialization.

           frame
               Evaluate expressions for each incoming frame. This is way slower than the init mode since it requires all the
               scalers to be re-computed, but it allows advanced dynamic expressions.

           Default value is init.

       dither
           Set dithering to reduce the circular banding effects. Default is 1 (enabled).

       aspect
           Set vignette aspect. This setting allows one to adjust the shape of the vignette.  Setting this value to the SAR of the
           input will make a rectangular vignetting following the dimensions of the video.

           Default is "1/1".

       Expressions

       The alpha, x0 and y0 expressions can contain the following parameters.

       w
       h   input width and height

       n   the number of input frame, starting from 0

       pts the PTS (Presentation TimeStamp) time of the filtered video frame, expressed in TB units, NAN if undefined

       r   frame rate of the input video, NAN if the input frame rate is unknown

       t   the PTS (Presentation TimeStamp) of the filtered video frame, expressed in seconds, NAN if undefined

       tb  time base of the input video

       Examples

       •   Apply simple strong vignetting effect:

                   vignette=PI/4

       •   Make a flickering vignetting:

                   vignette='PI/4+random(1)*PI/50':eval=frame

   vmafmotion
       Obtain the average VMAF motion score of a video.  It is one of the component metrics of VMAF.

       The obtained average motion score is printed through the logging system.

       The filter accepts the following options:

       stats_file
           If specified, the filter will use the named file to save the motion score of each frame with respect to the previous
           frame.  When filename equals "-" the data is sent to standard output.

       Example:

               ffmpeg -i ref.mpg -vf vmafmotion -f null -

   vstack
       Stack input videos vertically.

       All streams must be of same pixel format and of same width.

       Note that this filter is faster than using overlay and pad filter to create same output.

       The filter accepts the following options:

       inputs
           Set number of input streams. Default is 2.

       shortest
           If set to 1, force the output to terminate when the shortest input terminates. Default value is 0.

   w3fdif
       Deinterlace the input video ("w3fdif" stands for "Weston 3 Field Deinterlacing Filter").

       Based on the process described by Martin Weston for BBC R&D, and implemented based on the de-interlace algorithm written by
       Jim Easterbrook for BBC R&D, the Weston 3 field deinterlacing filter uses filter coefficients calculated by BBC R&D.

       This filter uses field-dominance information in frame to decide which of each pair of fields to place first in the output.
       If it gets it wrong use setfield filter before "w3fdif" filter.

       There are two sets of filter coefficients, so called "simple" and "complex". Which set of filter coefficients is used can be
       set by passing an optional parameter:

       filter
           Set the interlacing filter coefficients. Accepts one of the following values:

           simple
               Simple filter coefficient set.

           complex
               More-complex filter coefficient set.

           Default value is complex.

       mode
           The interlacing mode to adopt. It accepts one of the following values:

           frame
               Output one frame for each frame.

           field
               Output one frame for each field.

           The default value is "field".

       parity
           The picture field parity assumed for the input interlaced video. It accepts one of the following values:

           tff Assume the top field is first.

           bff Assume the bottom field is first.

           auto
               Enable automatic detection of field parity.

           The default value is "auto".  If the interlacing is unknown or the decoder does not export this information, top field
           first will be assumed.

       deint
           Specify which frames to deinterlace. Accepts one of the following values:

           all Deinterlace all frames,

           interlaced
               Only deinterlace frames marked as interlaced.

           Default value is all.

       Commands

       This filter supports same commands as options.

   waveform
       Video waveform monitor.

       The waveform monitor plots color component intensity. By default luminance only. Each column of the waveform corresponds to
       a column of pixels in the source video.

       It accepts the following options:

       mode, m
           Can be either "row", or "column". Default is "column".  In row mode, the graph on the left side represents color
           component value 0 and the right side represents value = 255. In column mode, the top side represents color component
           value = 0 and bottom side represents value = 255.

       intensity, i
           Set intensity. Smaller values are useful to find out how many values of the same luminance are distributed across input
           rows/columns.  Default value is 0.04. Allowed range is [0, 1].

       mirror, r
           Set mirroring mode. 0 means unmirrored, 1 means mirrored.  In mirrored mode, higher values will be represented on the
           left side for "row" mode and at the top for "column" mode. Default is 1 (mirrored).

       display, d
           Set display mode.  It accepts the following values:

           overlay
               Presents information identical to that in the "parade", except that the graphs representing color components are
               superimposed directly over one another.

               This display mode makes it easier to spot relative differences or similarities in overlapping areas of the color
               components that are supposed to be identical, such as neutral whites, grays, or blacks.

           stack
               Display separate graph for the color components side by side in "row" mode or one below the other in "column" mode.

           parade
               Display separate graph for the color components side by side in "column" mode or one below the other in "row" mode.

               Using this display mode makes it easy to spot color casts in the highlights and shadows of an image, by comparing
               the contours of the top and the bottom graphs of each waveform. Since whites, grays, and blacks are characterized by
               exactly equal amounts of red, green, and blue, neutral areas of the picture should display three waveforms of
               roughly equal width/height. If not, the correction is easy to perform by making level adjustments the three
               waveforms.

           Default is "stack".

       components, c
           Set which color components to display. Default is 1, which means only luminance or red color component if input is in
           RGB colorspace. If is set for example to 7 it will display all 3 (if) available color components.

       envelope, e
           none
               No envelope, this is default.

           instant
               Instant envelope, minimum and maximum values presented in graph will be easily visible even with small "step" value.

           peak
               Hold minimum and maximum values presented in graph across time. This way you can still spot out of range values
               without constantly looking at waveforms.

           peak+instant
               Peak and instant envelope combined together.

       filter, f
           lowpass
               No filtering, this is default.

           flat
               Luma and chroma combined together.

           aflat
               Similar as above, but shows difference between blue and red chroma.

           xflat
               Similar as above, but use different colors.

           yflat
               Similar as above, but again with different colors.

           chroma
               Displays only chroma.

           color
               Displays actual color value on waveform.

           acolor
               Similar as above, but with luma showing frequency of chroma values.

       graticule, g
           Set which graticule to display.

           none
               Do not display graticule.

           green
               Display green graticule showing legal broadcast ranges.

           orange
               Display orange graticule showing legal broadcast ranges.

           invert
               Display invert graticule showing legal broadcast ranges.

       opacity, o
           Set graticule opacity.

       flags, fl
           Set graticule flags.

           numbers
               Draw numbers above lines. By default enabled.

           dots
               Draw dots instead of lines.

       scale, s
           Set scale used for displaying graticule.

           digital
           millivolts
           ire

           Default is digital.

       bgopacity, b
           Set background opacity.

       tint0, t0
       tint1, t1
           Set tint for output.  Only used with lowpass filter and when display is not overlay and input pixel formats are not RGB.

       fitmode, fm
           Set sample aspect ratio of video output frames.  Can be used to configure waveform so it is not streched too much in one
           of directions.

           none
               Set sample aspect ration to 1/1.

           size
               Set sample aspect ratio to match input size of video

           Default is none.

   weave, doubleweave
       The "weave" takes a field-based video input and join each two sequential fields into single frame, producing a new double
       height clip with half the frame rate and half the frame count.

       The "doubleweave" works same as "weave" but without halving frame rate and frame count.

       It accepts the following option:

       first_field
           Set first field. Available values are:

           top, t
               Set the frame as top-field-first.

           bottom, b
               Set the frame as bottom-field-first.

       Examples

       •   Interlace video using select and separatefields filter:

                   separatefields,select=eq(mod(n,4),0)+eq(mod(n,4),3),weave

   xbr
       Apply the xBR high-quality magnification filter which is designed for pixel art. It follows a set of edge-detection rules,
       see <https://forums.libretro.com/t/xbr-algorithm-tutorial/123>.

       It accepts the following option:

       n   Set the scaling dimension: 2 for "2xBR", 3 for "3xBR" and 4 for "4xBR".  Default is 3.

   xcorrelate
       Apply normalized cross-correlation between first and second input video stream.

       Second input video stream dimensions must be lower than first input video stream.

       The filter accepts the following options:

       planes
           Set which planes to process.

       secondary
           Set which secondary video frames will be processed from second input video stream, can be first or all. Default is all.

       The "xcorrelate" filter also supports the framesync options.

   xfade
       Apply cross fade from one input video stream to another input video stream.  The cross fade is applied for specified
       duration.

       Both inputs must be constant frame-rate and have the same resolution, pixel format, frame rate and timebase.

       The filter accepts the following options:

       transition
           Set one of available transition effects:

           custom
           fade
           wipeleft
           wiperight
           wipeup
           wipedown
           slideleft
           slideright
           slideup
           slidedown
           circlecrop
           rectcrop
           distance
           fadeblack
           fadewhite
           radial
           smoothleft
           smoothright
           smoothup
           smoothdown
           circleopen
           circleclose
           vertopen
           vertclose
           horzopen
           horzclose
           dissolve
           pixelize
           diagtl
           diagtr
           diagbl
           diagbr
           hlslice
           hrslice
           vuslice
           vdslice
           hblur
           fadegrays
           wipetl
           wipetr
           wipebl
           wipebr
           squeezeh
           squeezev
           zoomin
           fadefast
           fadeslow

           Default transition effect is fade.

       duration
           Set cross fade duration in seconds.  Range is 0 to 60 seconds.  Default duration is 1 second.

       offset
           Set cross fade start relative to first input stream in seconds.  Default offset is 0.

       expr
           Set expression for custom transition effect.

           The expressions can use the following variables and functions:

           X
           Y   The coordinates of the current sample.

           W
           H   The width and height of the image.

           P   Progress of transition effect.

           PLANE
               Currently processed plane.

           A   Return value of first input at current location and plane.

           B   Return value of second input at current location and plane.

           a0(x, y)
           a1(x, y)
           a2(x, y)
           a3(x, y)
               Return the value of the pixel at location (x,y) of the first/second/third/fourth component of first input.

           b0(x, y)
           b1(x, y)
           b2(x, y)
           b3(x, y)
               Return the value of the pixel at location (x,y) of the first/second/third/fourth component of second input.

       Examples

       •   Cross fade from one input video to another input video, with fade transition and duration of transition of 2 seconds
           starting at offset of 5 seconds:

                   ffmpeg -i first.mp4 -i second.mp4 -filter_complex xfade=transition=fade:duration=2:offset=5 output.mp4

   xmedian
       Pick median pixels from several input videos.

       The filter accepts the following options:

       inputs
           Set number of inputs.  Default is 3. Allowed range is from 3 to 255.  If number of inputs is even number, than result
           will be mean value between two median values.

       planes
           Set which planes to filter. Default value is 15, by which all planes are processed.

       percentile
           Set median percentile. Default value is 0.5.  Default value of 0.5 will pick always median values, while 0 will pick
           minimum values, and 1 maximum values.

       Commands

       This filter supports all above options as commands, excluding option "inputs".

   xstack
       Stack video inputs into custom layout.

       All streams must be of same pixel format.

       The filter accepts the following options:

       inputs
           Set number of input streams. Default is 2.

       layout
           Specify layout of inputs.  This option requires the desired layout configuration to be explicitly set by the user.  This
           sets position of each video input in output. Each input is separated by '|'.  The first number represents the column,
           and the second number represents the row.  Numbers start at 0 and are separated by '_'. Optionally one can use wX and
           hX, where X is video input from which to take width or height.  Multiple values can be used when separated by '+'. In
           such case values are summed together.

           Note that if inputs are of different sizes gaps may appear, as not all of the output video frame will be filled.
           Similarly, videos can overlap each other if their position doesn't leave enough space for the full frame of adjoining
           videos.

           For 2 inputs, a default layout of "0_0|w0_0" (equivalent to "grid=2x1") is set. In all other cases, a layout or a grid
           must be set by the user. Either "grid" or "layout" can be specified at a time.  Specifying both will result in an error.

       grid
           Specify a fixed size grid of inputs.  This option is used to create a fixed size grid of the input streams. Set the grid
           size in the form "COLUMNSxROWS". There must be "ROWS * COLUMNS" input streams and they will be arranged as a grid with
           "ROWS" rows and "COLUMNS" columns. When using this option, each input stream within a row must have the same height and
           all the rows must have the same width.

           If "grid" is set, then "inputs" option is ignored and is implicitly set to "ROWS * COLUMNS".

           For 2 inputs, a default grid of "2x1" (equivalent to "layout=0_0|w0_0") is set. In all other cases, a layout or a grid
           must be set by the user. Either "grid" or "layout" can be specified at a time.  Specifying both will result in an error.

       shortest
           If set to 1, force the output to terminate when the shortest input terminates. Default value is 0.

       fill
           If set to valid color, all unused pixels will be filled with that color.  By default fill is set to none, so it is
           disabled.

       Examples

       •   Display 4 inputs into 2x2 grid.

           Layout:

                   input1(0, 0)  | input3(w0, 0)
                   input2(0, h0) | input4(w0, h0)

                   xstack=inputs=4:layout=0_0|0_h0|w0_0|w0_h0

           Note that if inputs are of different sizes, gaps or overlaps may occur.

       •   Display 4 inputs into 1x4 grid.

           Layout:

                   input1(0, 0)
                   input2(0, h0)
                   input3(0, h0+h1)
                   input4(0, h0+h1+h2)

                   xstack=inputs=4:layout=0_0|0_h0|0_h0+h1|0_h0+h1+h2

           Note that if inputs are of different widths, unused space will appear.

       •   Display 9 inputs into 3x3 grid.

           Layout:

                   input1(0, 0)       | input4(w0, 0)      | input7(w0+w3, 0)
                   input2(0, h0)      | input5(w0, h0)     | input8(w0+w3, h0)
                   input3(0, h0+h1)   | input6(w0, h0+h1)  | input9(w0+w3, h0+h1)

                   xstack=inputs=9:layout=0_0|0_h0|0_h0+h1|w0_0|w0_h0|w0_h0+h1|w0+w3_0|w0+w3_h0|w0+w3_h0+h1

           Note that if inputs are of different sizes, gaps or overlaps may occur.

       •   Display 16 inputs into 4x4 grid.

           Layout:

                   input1(0, 0)       | input5(w0, 0)       | input9 (w0+w4, 0)       | input13(w0+w4+w8, 0)
                   input2(0, h0)      | input6(w0, h0)      | input10(w0+w4, h0)      | input14(w0+w4+w8, h0)
                   input3(0, h0+h1)   | input7(w0, h0+h1)   | input11(w0+w4, h0+h1)   | input15(w0+w4+w8, h0+h1)
                   input4(0, h0+h1+h2)| input8(w0, h0+h1+h2)| input12(w0+w4, h0+h1+h2)| input16(w0+w4+w8, h0+h1+h2)

                   xstack=inputs=16:layout=0_0|0_h0|0_h0+h1|0_h0+h1+h2|w0_0|w0_h0|w0_h0+h1|w0_h0+h1+h2|w0+w4_0|
                   w0+w4_h0|w0+w4_h0+h1|w0+w4_h0+h1+h2|w0+w4+w8_0|w0+w4+w8_h0|w0+w4+w8_h0+h1|w0+w4+w8_h0+h1+h2

           Note that if inputs are of different sizes, gaps or overlaps may occur.

   yadif
       Deinterlace the input video ("yadif" means "yet another deinterlacing filter").

       It accepts the following parameters:

       mode
           The interlacing mode to adopt. It accepts one of the following values:

           0, send_frame
               Output one frame for each frame.

           1, send_field
               Output one frame for each field.

           2, send_frame_nospatial
               Like "send_frame", but it skips the spatial interlacing check.

           3, send_field_nospatial
               Like "send_field", but it skips the spatial interlacing check.

           The default value is "send_frame".

       parity
           The picture field parity assumed for the input interlaced video. It accepts one of the following values:

           0, tff
               Assume the top field is first.

           1, bff
               Assume the bottom field is first.

           -1, auto
               Enable automatic detection of field parity.

           The default value is "auto".  If the interlacing is unknown or the decoder does not export this information, top field
           first will be assumed.

       deint
           Specify which frames to deinterlace. Accepts one of the following values:

           0, all
               Deinterlace all frames.

           1, interlaced
               Only deinterlace frames marked as interlaced.

           The default value is "all".

   yadif_cuda
       Deinterlace the input video using the yadif algorithm, but implemented in CUDA so that it can work as part of a GPU
       accelerated pipeline with nvdec and/or nvenc.

       It accepts the following parameters:

       mode
           The interlacing mode to adopt. It accepts one of the following values:

           0, send_frame
               Output one frame for each frame.

           1, send_field
               Output one frame for each field.

           2, send_frame_nospatial
               Like "send_frame", but it skips the spatial interlacing check.

           3, send_field_nospatial
               Like "send_field", but it skips the spatial interlacing check.

           The default value is "send_frame".

       parity
           The picture field parity assumed for the input interlaced video. It accepts one of the following values:

           0, tff
               Assume the top field is first.

           1, bff
               Assume the bottom field is first.

           -1, auto
               Enable automatic detection of field parity.

           The default value is "auto".  If the interlacing is unknown or the decoder does not export this information, top field
           first will be assumed.

       deint
           Specify which frames to deinterlace. Accepts one of the following values:

           0, all
               Deinterlace all frames.

           1, interlaced
               Only deinterlace frames marked as interlaced.

           The default value is "all".

   yaepblur
       Apply blur filter while preserving edges ("yaepblur" means "yet another edge preserving blur filter").  The algorithm is
       described in "J. S. Lee, Digital image enhancement and noise filtering by use of local statistics, IEEE Trans. Pattern Anal.
       Mach. Intell. PAMI-2, 1980."

       It accepts the following parameters:

       radius, r
           Set the window radius. Default value is 3.

       planes, p
           Set which planes to filter. Default is only the first plane.

       sigma, s
           Set blur strength. Default value is 128.

       Commands

       This filter supports same commands as options.

   zoompan
       Apply Zoom & Pan effect.

       This filter accepts the following options:

       zoom, z
           Set the zoom expression. Range is 1-10. Default is 1.

       x
       y   Set the x and y expression. Default is 0.

       d   Set the duration expression in number of frames.  This sets for how many number of frames effect will last for single
           input image. Default is 90.

       s   Set the output image size, default is 'hd720'.

       fps Set the output frame rate, default is '25'.

       Each expression can contain the following constants:

       in_w, iw
           Input width.

       in_h, ih
           Input height.

       out_w, ow
           Output width.

       out_h, oh
           Output height.

       in  Input frame count.

       on  Output frame count.

       in_time, it
           The input timestamp expressed in seconds. It's NAN if the input timestamp is unknown.

       out_time, time, ot
           The output timestamp expressed in seconds.

       x
       y   Last calculated 'x' and 'y' position from 'x' and 'y' expression for current input frame.

       px
       py  'x' and 'y' of last output frame of previous input frame or 0 when there was not yet such frame (first input frame).

       zoom
           Last calculated zoom from 'z' expression for current input frame.

       pzoom
           Last calculated zoom of last output frame of previous input frame.

       duration
           Number of output frames for current input frame. Calculated from 'd' expression for each input frame.

       pduration
           number of output frames created for previous input frame

       a   Rational number: input width / input height

       sar sample aspect ratio

       dar display aspect ratio

       Examples

       •   Zoom in up to 1.5x and pan at same time to some spot near center of picture:

                   zoompan=z='min(zoom+0.0015,1.5)':d=700:x='if(gte(zoom,1.5),x,x+1/a)':y='if(gte(zoom,1.5),y,y+1)':s=640x360

       •   Zoom in up to 1.5x and pan always at center of picture:

                   zoompan=z='min(zoom+0.0015,1.5)':d=700:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)'

       •   Same as above but without pausing:

                   zoompan=z='min(max(zoom,pzoom)+0.0015,1.5)':d=1:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)'

       •   Zoom in 2x into center of picture only for the first second of the input video:

                   zoompan=z='if(between(in_time,0,1),2,1)':d=1:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)'

   zscale
       Scale (resize) the input video, using the z.lib library: <https://github.com/sekrit-twc/zimg>. To enable compilation of this
       filter, you need to configure FFmpeg with "--enable-libzimg".

       The zscale filter forces the output display aspect ratio to be the same as the input, by changing the output sample aspect
       ratio.

       If the input image format is different from the format requested by the next filter, the zscale filter will convert the
       input to the requested format.

       Options

       The filter accepts the following options.

       width, w
       height, h
           Set the output video dimension expression. Default value is the input dimension.

           If the width or w value is 0, the input width is used for the output. If the height or h value is 0, the input height is
           used for the output.

           If one and only one of the values is -n with n >= 1, the zscale filter will use a value that maintains the aspect ratio
           of the input image, calculated from the other specified dimension. After that it will, however, make sure that the
           calculated dimension is divisible by n and adjust the value if necessary.

           If both values are -n with n >= 1, the behavior will be identical to both values being set to 0 as previously detailed.

           See below for the list of accepted constants for use in the dimension expression.

       size, s
           Set the video size. For the syntax of this option, check the "Video size" section in the ffmpeg-utils manual.

       dither, d
           Set the dither type.

           Possible values are:

           none
           ordered
           random
           error_diffusion

           Default is none.

       filter, f
           Set the resize filter type.

           Possible values are:

           point
           bilinear
           bicubic
           spline16
           spline36
           lanczos

           Default is bilinear.

       range, r
           Set the color range.

           Possible values are:

           input
           limited
           full

           Default is same as input.

       primaries, p
           Set the color primaries.

           Possible values are:

           input
           709
           unspecified
           170m
           240m
           2020

           Default is same as input.

       transfer, t
           Set the transfer characteristics.

           Possible values are:

           input
           709
           unspecified
           601
           linear
           2020_10
           2020_12
           smpte2084
           iec61966-2-1
           arib-std-b67

           Default is same as input.

       matrix, m
           Set the colorspace matrix.

           Possible value are:

           input
           709
           unspecified
           470bg
           170m
           2020_ncl
           2020_cl

           Default is same as input.

       rangein, rin
           Set the input color range.

           Possible values are:

           input
           limited
           full

           Default is same as input.

       primariesin, pin
           Set the input color primaries.

           Possible values are:

           input
           709
           unspecified
           170m
           240m
           2020

           Default is same as input.

       transferin, tin
           Set the input transfer characteristics.

           Possible values are:

           input
           709
           unspecified
           601
           linear
           2020_10
           2020_12

           Default is same as input.

       matrixin, min
           Set the input colorspace matrix.

           Possible value are:

           input
           709
           unspecified
           470bg
           170m
           2020_ncl
           2020_cl
       chromal, c
           Set the output chroma location.

           Possible values are:

           input
           left
           center
           topleft
           top
           bottomleft
           bottom
       chromalin, cin
           Set the input chroma location.

           Possible values are:

           input
           left
           center
           topleft
           top
           bottomleft
           bottom
       npl Set the nominal peak luminance.

       param_a
           Parameter A for scaling filters. Parameter "b" for bicubic, and the number of filter taps for lanczos.

       param_b
           Parameter B for scaling filters. Parameter "c" for bicubic.

       The values of the w and h options are expressions containing the following constants:

       in_w
       in_h
           The input width and height

       iw
       ih  These are the same as in_w and in_h.

       out_w
       out_h
           The output (scaled) width and height

       ow
       oh  These are the same as out_w and out_h

       a   The same as iw / ih

       sar input sample aspect ratio

       dar The input display aspect ratio. Calculated from "(iw / ih) * sar".

       hsub
       vsub
           horizontal and vertical input chroma subsample values. For example for the pixel format "yuv422p" hsub is 2 and vsub is
           1.

       ohsub
       ovsub
           horizontal and vertical output chroma subsample values. For example for the pixel format "yuv422p" hsub is 2 and vsub is
           1.

       Commands

       This filter supports the following commands:

       width, w
       height, h
           Set the output video dimension expression.  The command accepts the same syntax of the corresponding option.

           If the specified expression is not valid, it is kept at its current value.

OPENCL VIDEO FILTERS
       Below is a description of the currently available OpenCL video filters.

       To enable compilation of these filters you need to configure FFmpeg with "--enable-opencl".

       Running OpenCL filters requires you to initialize a hardware device and to pass that device to all filters in any filter
       graph.

       -init_hw_device opencl[=name][:device[,key=value...]]
           Initialise a new hardware device of type opencl called name, using the given device parameters.

       -filter_hw_device name
           Pass the hardware device called name to all filters in any filter graph.

       For more detailed information see <https://www.ffmpeg.org/ffmpeg.html#Advanced-Video-options>

       •   Example of choosing the first device on the second platform and running avgblur_opencl filter with default parameters on
           it.

                   -init_hw_device opencl=gpu:1.0 -filter_hw_device gpu -i INPUT -vf "hwupload, avgblur_opencl, hwdownload" OUTPUT

       Since OpenCL filters are not able to access frame data in normal memory, all frame data needs to be uploaded(hwupload) to
       hardware surfaces connected to the appropriate device before being used and then downloaded(hwdownload) back to normal
       memory. Note that hwupload will upload to a surface with the same layout as the software frame, so it may be necessary to
       add a format filter immediately before to get the input into the right format and hwdownload does not support all formats on
       the output - it may be necessary to insert an additional format filter immediately following in the graph to get the output
       in a supported format.

   avgblur_opencl
       Apply average blur filter.

       The filter accepts the following options:

       sizeX
           Set horizontal radius size.  Range is "[1, 1024]" and default value is 1.

       planes
           Set which planes to filter. Default value is 0xf, by which all planes are processed.

       sizeY
           Set vertical radius size. Range is "[1, 1024]" and default value is 0. If zero, "sizeX" value will be used.

       Example

       •   Apply average blur filter with horizontal and vertical size of 3, setting each pixel of the output to the average value
           of the 7x7 region centered on it in the input. For pixels on the edges of the image, the region does not extend beyond
           the image boundaries, and so out-of-range coordinates are not used in the calculations.

                   -i INPUT -vf "hwupload, avgblur_opencl=3, hwdownload" OUTPUT

   boxblur_opencl
       Apply a boxblur algorithm to the input video.

       It accepts the following parameters:

       luma_radius, lr
       luma_power, lp
       chroma_radius, cr
       chroma_power, cp
       alpha_radius, ar
       alpha_power, ap

       A description of the accepted options follows.

       luma_radius, lr
       chroma_radius, cr
       alpha_radius, ar
           Set an expression for the box radius in pixels used for blurring the corresponding input plane.

           The radius value must be a non-negative number, and must not be greater than the value of the expression "min(w,h)/2"
           for the luma and alpha planes, and of "min(cw,ch)/2" for the chroma planes.

           Default value for luma_radius is "2". If not specified, chroma_radius and alpha_radius default to the corresponding
           value set for luma_radius.

           The expressions can contain the following constants:

           w
           h   The input width and height in pixels.

           cw
           ch  The input chroma image width and height in pixels.

           hsub
           vsub
               The horizontal and vertical chroma subsample values. For example, for the pixel format "yuv422p", hsub is 2 and vsub
               is 1.

       luma_power, lp
       chroma_power, cp
       alpha_power, ap
           Specify how many times the boxblur filter is applied to the corresponding plane.

           Default value for luma_power is 2. If not specified, chroma_power and alpha_power default to the corresponding value set
           for luma_power.

           A value of 0 will disable the effect.

       Examples

       Apply boxblur filter, setting each pixel of the output to the average value of box-radiuses luma_radius, chroma_radius,
       alpha_radius for each plane respectively. The filter will apply luma_power, chroma_power, alpha_power times onto the
       corresponding plane. For pixels on the edges of the image, the radius does not extend beyond the image boundaries, and so
       out-of-range coordinates are not used in the calculations.

       •   Apply a boxblur filter with the luma, chroma, and alpha radius set to 2 and luma, chroma, and alpha power set to 3. The
           filter will run 3 times with box-radius set to 2 for every plane of the image.

                   -i INPUT -vf "hwupload, boxblur_opencl=luma_radius=2:luma_power=3, hwdownload" OUTPUT
                   -i INPUT -vf "hwupload, boxblur_opencl=2:3, hwdownload" OUTPUT

       •   Apply a boxblur filter with luma radius set to 2, luma_power to 1, chroma_radius to 4, chroma_power to 5, alpha_radius
           to 3 and alpha_power to 7.

           For the luma plane, a 2x2 box radius will be run once.

           For the chroma plane, a 4x4 box radius will be run 5 times.

           For the alpha plane, a 3x3 box radius will be run 7 times.

                   -i INPUT -vf "hwupload, boxblur_opencl=2:1:4:5:3:7, hwdownload" OUTPUT

   colorkey_opencl
       RGB colorspace color keying.

       The filter accepts the following options:

       color
           The color which will be replaced with transparency.

       similarity
           Similarity percentage with the key color.

           0.01 matches only the exact key color, while 1.0 matches everything.

       blend
           Blend percentage.

           0.0 makes pixels either fully transparent, or not transparent at all.

           Higher values result in semi-transparent pixels, with a higher transparency the more similar the pixels color is to the
           key color.

       Examples

       •   Make every semi-green pixel in the input transparent with some slight blending:

                   -i INPUT -vf "hwupload, colorkey_opencl=green:0.3:0.1, hwdownload" OUTPUT

   convolution_opencl
       Apply convolution of 3x3, 5x5, 7x7 matrix.

       The filter accepts the following options:

       0m
       1m
       2m
       3m  Set matrix for each plane.  Matrix is sequence of 9, 25 or 49 signed numbers.  Default value for each plane is "0 0 0 0
           1 0 0 0 0".

       0rdiv
       1rdiv
       2rdiv
       3rdiv
           Set multiplier for calculated value for each plane.  If unset or 0, it will be sum of all matrix elements.  The option
           value must be a float number greater or equal to 0.0. Default value is 1.0.

       0bias
       1bias
       2bias
       3bias
           Set bias for each plane. This value is added to the result of the multiplication.  Useful for making the overall image
           brighter or darker.  The option value must be a float number greater or equal to 0.0. Default value is 0.0.

       Examples

       •   Apply sharpen:

                   -i INPUT -vf "hwupload, convolution_opencl=0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0, hwdownload" OUTPUT

       •   Apply blur:

                   -i INPUT -vf "hwupload, convolution_opencl=1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1/9:1/9:1/9:1/9, hwdownload" OUTPUT

       •   Apply edge enhance:

                   -i INPUT -vf "hwupload, convolution_opencl=0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:5:1:1:1:0:128:128:128, hwdownload" OUTPUT

       •   Apply edge detect:

                   -i INPUT -vf "hwupload, convolution_opencl=0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:5:5:5:1:0:128:128:128, hwdownload" OUTPUT

       •   Apply laplacian edge detector which includes diagonals:

                   -i INPUT -vf "hwupload, convolution_opencl=1 1 1 1 -8 1 1 1 1:1 1 1 1 -8 1 1 1 1:1 1 1 1 -8 1 1 1 1:1 1 1 1 -8 1 1 1 1:5:5:5:1:0:128:128:0, hwdownload" OUTPUT

       •   Apply emboss:

                   -i INPUT -vf "hwupload, convolution_opencl=-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2, hwdownload" OUTPUT

   erosion_opencl
       Apply erosion effect to the video.

       This filter replaces the pixel by the local(3x3) minimum.

       It accepts the following options:

       threshold0
       threshold1
       threshold2
       threshold3
           Limit the maximum change for each plane. Range is "[0, 65535]" and default value is 65535.  If 0, plane will remain
           unchanged.

       coordinates
           Flag which specifies the pixel to refer to.  Range is "[0, 255]" and default value is 255, i.e. all eight pixels are
           used.

           Flags to local 3x3 coordinates region centered on "x":

               1 2 3

               4 x 5

               6 7 8

       Example

       •   Apply erosion filter with threshold0 set to 30, threshold1 set 40, threshold2 set to 50 and coordinates set to 231,
           setting each pixel of the output to the local minimum between pixels: 1, 2, 3, 6, 7, 8 of the 3x3 region centered on it
           in the input. If the difference between input pixel and local minimum is more then threshold of the corresponding plane,
           output pixel will be set to input pixel - threshold of corresponding plane.

                   -i INPUT -vf "hwupload, erosion_opencl=30:40:50:coordinates=231, hwdownload" OUTPUT

   deshake_opencl
       Feature-point based video stabilization filter.

       The filter accepts the following options:

       tripod
           Simulates a tripod by preventing any camera movement whatsoever from the original frame. Defaults to 0.

       debug
           Whether or not additional debug info should be displayed, both in the processed output and in the console.

           Note that in order to see console debug output you will also need to pass "-v verbose" to ffmpeg.

           Viewing point matches in the output video is only supported for RGB input.

           Defaults to 0.

       adaptive_crop
           Whether or not to do a tiny bit of cropping at the borders to cut down on the amount of mirrored pixels.

           Defaults to 1.

       refine_features
           Whether or not feature points should be refined at a sub-pixel level.

           This can be turned off for a slight performance gain at the cost of precision.

           Defaults to 1.

       smooth_strength
           The strength of the smoothing applied to the camera path from 0.0 to 1.0.

           1.0 is the maximum smoothing strength while values less than that result in less smoothing.

           0.0 causes the filter to adaptively choose a smoothing strength on a per-frame basis.

           Defaults to 0.0.

       smooth_window_multiplier
           Controls the size of the smoothing window (the number of frames buffered to determine motion information from).

           The size of the smoothing window is determined by multiplying the framerate of the video by this number.

           Acceptable values range from 0.1 to 10.0.

           Larger values increase the amount of motion data available for determining how to smooth the camera path, potentially
           improving smoothness, but also increase latency and memory usage.

           Defaults to 2.0.

       Examples

       •   Stabilize a video with a fixed, medium smoothing strength:

                   -i INPUT -vf "hwupload, deshake_opencl=smooth_strength=0.5, hwdownload" OUTPUT

       •   Stabilize a video with debugging (both in console and in rendered video):

                   -i INPUT -filter_complex "[0:v]format=rgba, hwupload, deshake_opencl=debug=1, hwdownload, format=rgba, format=yuv420p" -v verbose OUTPUT

   dilation_opencl
       Apply dilation effect to the video.

       This filter replaces the pixel by the local(3x3) maximum.

       It accepts the following options:

       threshold0
       threshold1
       threshold2
       threshold3
           Limit the maximum change for each plane. Range is "[0, 65535]" and default value is 65535.  If 0, plane will remain
           unchanged.

       coordinates
           Flag which specifies the pixel to refer to.  Range is "[0, 255]" and default value is 255, i.e. all eight pixels are
           used.

           Flags to local 3x3 coordinates region centered on "x":

               1 2 3

               4 x 5

               6 7 8

       Example

       •   Apply dilation filter with threshold0 set to 30, threshold1 set 40, threshold2 set to 50 and coordinates set to 231,
           setting each pixel of the output to the local maximum between pixels: 1, 2, 3, 6, 7, 8 of the 3x3 region centered on it
           in the input. If the difference between input pixel and local maximum is more then threshold of the corresponding plane,
           output pixel will be set to input pixel + threshold of corresponding plane.

                   -i INPUT -vf "hwupload, dilation_opencl=30:40:50:coordinates=231, hwdownload" OUTPUT

   nlmeans_opencl
       Non-local Means denoise filter through OpenCL, this filter accepts same options as nlmeans.

   overlay_opencl
       Overlay one video on top of another.

       It takes two inputs and has one output. The first input is the "main" video on which the second input is overlaid.  This
       filter requires same memory layout for all the inputs. So, format conversion may be needed.

       The filter accepts the following options:

       x   Set the x coordinate of the overlaid video on the main video.  Default value is 0.

       y   Set the y coordinate of the overlaid video on the main video.  Default value is 0.

       Examples

       •   Overlay an image LOGO at the top-left corner of the INPUT video. Both inputs are yuv420p format.

                   -i INPUT -i LOGO -filter_complex "[0:v]hwupload[a], [1:v]format=yuv420p, hwupload[b], [a][b]overlay_opencl, hwdownload" OUTPUT

       •   The inputs have same memory layout for color channels , the overlay has additional alpha plane, like INPUT is yuv420p,
           and the LOGO is yuva420p.

                   -i INPUT -i LOGO -filter_complex "[0:v]hwupload[a], [1:v]format=yuva420p, hwupload[b], [a][b]overlay_opencl, hwdownload" OUTPUT

   pad_opencl
       Add paddings to the input image, and place the original input at the provided x, y coordinates.

       It accepts the following options:

       width, w
       height, h
           Specify an expression for the size of the output image with the paddings added. If the value for width or height is 0,
           the corresponding input