ffmpeg.man

FFMPEG(1)                                                                                                                FFMPEG(1)

NAME
       ffmpeg - ffmpeg video converter

SYNOPSIS
       ffmpeg [global_options] {[input_file_options] -i input_url} ... {[output_file_options] output_url} ...

DESCRIPTION
       ffmpeg is a very fast video and audio converter that can also grab from a live audio/video source. It can also convert
       between arbitrary sample rates and resize video on the fly with a high quality polyphase filter.

       ffmpeg reads from an arbitrary number of input "files" (which can be regular files, pipes, network streams, grabbing
       devices, etc.), specified by the "-i" option, and writes to an arbitrary number of output "files", which are specified by a
       plain output url. Anything found on the command line which cannot be interpreted as an option is considered to be an output
       url.

       Each input or output url can, in principle, contain any number of streams of different types
       (video/audio/subtitle/attachment/data). The allowed number and/or types of streams may be limited by the container format.
       Selecting which streams from which inputs will go into which output is either done automatically or with the "-map" option
       (see the Stream selection chapter).

       To refer to input files in options, you must use their indices (0-based). E.g.  the first input file is 0, the second is 1,
       etc. Similarly, streams within a file are referred to by their indices. E.g. "2:3" refers to the fourth stream in the third
       input file. Also see the Stream specifiers chapter.

       As a general rule, options are applied to the next specified file. Therefore, order is important, and you can have the same
       option on the command line multiple times. Each occurrence is then applied to the next input or output file.  Exceptions
       from this rule are the global options (e.g. verbosity level), which should be specified first.

       Do not mix input and output files -- first specify all input files, then all output files. Also do not mix options which
       belong to different files. All options apply ONLY to the next input or output file and are reset between files.

       •   To set the video bitrate of the output file to 64 kbit/s:

                   ffmpeg -i input.avi -b:v 64k -bufsize 64k output.avi

       •   To force the frame rate of the output file to 24 fps:

                   ffmpeg -i input.avi -r 24 output.avi

       •   To force the frame rate of the input file (valid for raw formats only) to 1 fps and the frame rate of the output file
           to 24 fps:

                   ffmpeg -r 1 -i input.m2v -r 24 output.avi

       The format option may be needed for raw input files.

DETAILED DESCRIPTION
       The transcoding process in ffmpeg for each output can be described by the following diagram:

                _______              ______________
               |       |            |              |
               | input |  demuxer   | encoded data |   decoder
               | file  | ---------> | packets      | -----+
               |_______|            |______________|      |
                                                          v
                                                      _________
                                                     |         |
                                                     | decoded |
                                                     | frames  |
                                                     |_________|
                ________             ______________       |
               |        |           |              |      |
               | output | <-------- | encoded data | <----+
               | file   |   muxer   | packets      |   encoder
               |________|           |______________|

       ffmpeg calls the libavformat library (containing demuxers) to read input files and get packets containing encoded data from
       them. When there are multiple input files, ffmpeg tries to keep them synchronized by tracking lowest timestamp on any
       active input stream.

       Encoded packets are then passed to the decoder (unless streamcopy is selected for the stream, see further for a
       description). The decoder produces uncompressed frames (raw video/PCM audio/...) which can be processed further by
       filtering (see next section). After filtering, the frames are passed to the encoder, which encodes them and outputs encoded
       packets. Finally those are passed to the muxer, which writes the encoded packets to the output file.

   Filtering
       Before encoding, ffmpeg can process raw audio and video frames using filters from the libavfilter library. Several chained
       filters form a filter graph. ffmpeg distinguishes between two types of filtergraphs: simple and complex.

       Simple filtergraphs

       Simple filtergraphs are those that have exactly one input and output, both of the same type. In the above diagram they can
       be represented by simply inserting an additional step between decoding and encoding:

                _________                        ______________
               |         |                      |              |
               | decoded |                      | encoded data |
               | frames  |\                   _ | packets      |
               |_________| \                  /||______________|
                            \   __________   /
                 simple     _\||          | /  encoder
                 filtergraph   | filtered |/
                               | frames   |
                               |__________|

       Simple filtergraphs are configured with the per-stream -filter option (with -vf and -af aliases for video and audio
       respectively).  A simple filtergraph for video can look for example like this:

                _______        _____________        _______        ________
               |       |      |             |      |       |      |        |
               | input | ---> | deinterlace | ---> | scale | ---> | output |
               |_______|      |_____________|      |_______|      |________|

       Note that some filters change frame properties but not frame contents. E.g. the "fps" filter in the example above changes
       number of frames, but does not touch the frame contents. Another example is the "setpts" filter, which only sets timestamps
       and otherwise passes the frames unchanged.

       Complex filtergraphs

       Complex filtergraphs are those which cannot be described as simply a linear processing chain applied to one stream. This is
       the case, for example, when the graph has more than one input and/or output, or when output stream type is different from
       input. They can be represented with the following diagram:

                _________
               |         |
               | input 0 |\                    __________
               |_________| \                  |          |
                            \   _________    /| output 0 |
                             \ |         |  / |__________|
                _________     \| complex | /
               |         |     |         |/
               | input 1 |---->| filter  |\
               |_________|     |         | \   __________
                              /| graph   |  \ |          |
                             / |         |   \| output 1 |
                _________   /  |_________|    |__________|
               |         | /
               | input 2 |/
               |_________|

       Complex filtergraphs are configured with the -filter_complex option.  Note that this option is global, since a complex
       filtergraph, by its nature, cannot be unambiguously associated with a single stream or file.

       The -lavfi option is equivalent to -filter_complex.

       A trivial example of a complex filtergraph is the "overlay" filter, which has two video inputs and one video output,
       containing one video overlaid on top of the other. Its audio counterpart is the "amix" filter.

   Stream copy
       Stream copy is a mode selected by supplying the "copy" parameter to the -codec option. It makes ffmpeg omit the decoding
       and encoding step for the specified stream, so it does only demuxing and muxing. It is useful for changing the container
       format or modifying container-level metadata. The diagram above will, in this case, simplify to this:

                _______              ______________            ________
               |       |            |              |          |        |
               | input |  demuxer   | encoded data |  muxer   | output |
               | file  | ---------> | packets      | -------> | file   |
               |_______|            |______________|          |________|

       Since there is no decoding or encoding, it is very fast and there is no quality loss. However, it might not work in some
       cases because of many factors. Applying filters is obviously also impossible, since filters work on uncompressed data.

STREAM SELECTION
       ffmpeg provides the "-map" option for manual control of stream selection in each output file. Users can skip "-map" and let
       ffmpeg perform automatic stream selection as described below. The "-vn / -an / -sn / -dn" options can be used to skip
       inclusion of video, audio, subtitle and data streams respectively, whether manually mapped or automatically selected,
       except for those streams which are outputs of complex filtergraphs.

   Description
       The sub-sections that follow describe the various rules that are involved in stream selection.  The examples that follow
       next show how these rules are applied in practice.

       While every effort is made to accurately reflect the behavior of the program, FFmpeg is under continuous development and
       the code may have changed since the time of this writing.

       Automatic stream selection

       In the absence of any map options for a particular output file, ffmpeg inspects the output format to check which type of
       streams can be included in it, viz. video, audio and/or subtitles. For each acceptable stream type, ffmpeg will pick one
       stream, when available, from among all the inputs.

       It will select that stream based upon the following criteria:

       •   for video, it is the stream with the highest resolution,

       •   for audio, it is the stream with the most channels,

       •   for subtitles, it is the first subtitle stream found but there's a caveat.  The output format's default subtitle
           encoder can be either text-based or image-based, and only a subtitle stream of the same type will be chosen.

       In the case where several streams of the same type rate equally, the stream with the lowest index is chosen.

       Data or attachment streams are not automatically selected and can only be included using "-map".

       Manual stream selection

       When "-map" is used, only user-mapped streams are included in that output file, with one possible exception for filtergraph
       outputs described below.

       Complex filtergraphs

       If there are any complex filtergraph output streams with unlabeled pads, they will be added to the first output file. This
       will lead to a fatal error if the stream type is not supported by the output format. In the absence of the map option, the
       inclusion of these streams leads to the automatic stream selection of their types being skipped. If map options are
       present, these filtergraph streams are included in addition to the mapped streams.

       Complex filtergraph output streams with labeled pads must be mapped once and exactly once.

       Stream handling

       Stream handling is independent of stream selection, with an exception for subtitles described below. Stream handling is set
       via the "-codec" option addressed to streams within a specific output file. In particular, codec options are applied by
       ffmpeg after the stream selection process and thus do not influence the latter. If no "-codec" option is specified for a
       stream type, ffmpeg will select the default encoder registered by the output file muxer.

       An exception exists for subtitles. If a subtitle encoder is specified for an output file, the first subtitle stream found
       of any type, text or image, will be included. ffmpeg does not validate if the specified encoder can convert the selected
       stream or if the converted stream is acceptable within the output format. This applies generally as well: when the user
       sets an encoder manually, the stream selection process cannot check if the encoded stream can be muxed into the output
       file.  If it cannot, ffmpeg will abort and all output files will fail to be processed.

   Examples
       The following examples illustrate the behavior, quirks and limitations of ffmpeg's stream selection methods.

       They assume the following three input files.

               input file 'A.avi'
                     stream 0: video 640x360
                     stream 1: audio 2 channels

               input file 'B.mp4'
                     stream 0: video 1920x1080
                     stream 1: audio 2 channels
                     stream 2: subtitles (text)
                     stream 3: audio 5.1 channels
                     stream 4: subtitles (text)

               input file 'C.mkv'
                     stream 0: video 1280x720
                     stream 1: audio 2 channels
                     stream 2: subtitles (image)

       Example: automatic stream selection

               ffmpeg -i A.avi -i B.mp4 out1.mkv out2.wav -map 1:a -c:a copy out3.mov

       There are three output files specified, and for the first two, no "-map" options are set, so ffmpeg will select streams for
       these two files automatically.

       out1.mkv is a Matroska container file and accepts video, audio and subtitle streams, so ffmpeg will try to select one of
       each type.For video, it will select "stream 0" from B.mp4, which has the highest resolution among all the input video
       streams.For audio, it will select "stream 3" from B.mp4, since it has the greatest number of channels.For subtitles, it
       will select "stream 2" from B.mp4, which is the first subtitle stream from among A.avi and B.mp4.

       out2.wav accepts only audio streams, so only "stream 3" from B.mp4 is selected.

       For out3.mov, since a "-map" option is set, no automatic stream selection will occur. The "-map 1:a" option will select all
       audio streams from the second input B.mp4. No other streams will be included in this output file.

       For the first two outputs, all included streams will be transcoded. The encoders chosen will be the default ones registered
       by each output format, which may not match the codec of the selected input streams.

       For the third output, codec option for audio streams has been set to "copy", so no decoding-filtering-encoding operations
       will occur, or can occur.  Packets of selected streams shall be conveyed from the input file and muxed within the output
       file.

       Example: automatic subtitles selection

               ffmpeg -i C.mkv out1.mkv -c:s dvdsub -an out2.mkv

       Although out1.mkv is a Matroska container file which accepts subtitle streams, only a video and audio stream shall be
       selected. The subtitle stream of C.mkv is image-based and the default subtitle encoder of the Matroska muxer is text-based,
       so a transcode operation for the subtitles is expected to fail and hence the stream isn't selected. However, in out2.mkv, a
       subtitle encoder is specified in the command and so, the subtitle stream is selected, in addition to the video stream. The
       presence of "-an" disables audio stream selection for out2.mkv.

       Example: unlabeled filtergraph outputs

               ffmpeg -i A.avi -i C.mkv -i B.mp4 -filter_complex "overlay" out1.mp4 out2.srt

       A filtergraph is setup here using the "-filter_complex" option and consists of a single video filter. The "overlay" filter
       requires exactly two video inputs, but none are specified, so the first two available video streams are used, those of
       A.avi and C.mkv. The output pad of the filter has no label and so is sent to the first output file out1.mp4. Due to this,
       automatic selection of the video stream is skipped, which would have selected the stream in B.mp4. The audio stream with
       most channels viz. "stream 3" in B.mp4, is chosen automatically. No subtitle stream is chosen however, since the MP4 format
       has no default subtitle encoder registered, and the user hasn't specified a subtitle encoder.

       The 2nd output file, out2.srt, only accepts text-based subtitle streams. So, even though the first subtitle stream
       available belongs to C.mkv, it is image-based and hence skipped.  The selected stream, "stream 2" in B.mp4, is the first
       text-based subtitle stream.

       Example: labeled filtergraph outputs

               ffmpeg -i A.avi -i B.mp4 -i C.mkv -filter_complex "[1:v]hue=s=0[outv];overlay;aresample" \
                      -map '[outv]' -an        out1.mp4 \
                                               out2.mkv \
                      -map '[outv]' -map 1:a:0 out3.mkv

       The above command will fail, as the output pad labelled "[outv]" has been mapped twice.  None of the output files shall be
       processed.

               ffmpeg -i A.avi -i B.mp4 -i C.mkv -filter_complex "[1:v]hue=s=0[outv];overlay;aresample" \
                      -an        out1.mp4 \
                                 out2.mkv \
                      -map 1:a:0 out3.mkv

       This command above will also fail as the hue filter output has a label, "[outv]", and hasn't been mapped anywhere.

       The command should be modified as follows,

               ffmpeg -i A.avi -i B.mp4 -i C.mkv -filter_complex "[1:v]hue=s=0,split=2[outv1][outv2];overlay;aresample" \
                       -map '[outv1]' -an        out1.mp4 \
                                                 out2.mkv \
                       -map '[outv2]' -map 1:a:0 out3.mkv

       The video stream from B.mp4 is sent to the hue filter, whose output is cloned once using the split filter, and both outputs
       labelled. Then a copy each is mapped to the first and third output files.

       The overlay filter, requiring two video inputs, uses the first two unused video streams. Those are the streams from A.avi
       and C.mkv. The overlay output isn't labelled, so it is sent to the first output file out1.mp4, regardless of the presence
       of the "-map" option.

       The aresample filter is sent the first unused audio stream, that of A.avi. Since this filter output is also unlabelled, it
       too is mapped to the first output file. The presence of "-an" only suppresses automatic or manual stream selection of audio
       streams, not outputs sent from filtergraphs. Both these mapped streams shall be ordered before the mapped stream in
       out1.mp4.

       The video, audio and subtitle streams mapped to "out2.mkv" are entirely determined by automatic stream selection.

       out3.mkv consists of the cloned video output from the hue filter and the first audio stream from B.mp4.

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 fmt (input/output)
           Force input or output file format. The format is normally auto detected for input files and guessed from the file
           extension for output files, so this option is not needed in most cases.

       -i url (input)
           input file url

       -y (global)
           Overwrite output files without asking.

       -n (global)
           Do not overwrite output files, and exit immediately if a specified output file already exists.

       -stream_loop number (input)
           Set number of times input stream shall be looped. Loop 0 means no loop, loop -1 means infinite loop.

       -recast_media (global)
           Allow forcing a decoder of a different media type than the one detected or designated by the demuxer. Useful for
           decoding media data muxed as data streams.

       -c[:stream_specifier] codec (input/output,per-stream)
       -codec[:stream_specifier] codec (input/output,per-stream)
           Select an encoder (when used before an output file) or a decoder (when used before an input file) for one or more
           streams. codec is the name of a decoder/encoder or a special value "copy" (output only) to indicate that the stream is
           not to be re-encoded.

           For example

                   ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT

           encodes all video streams with libx264 and copies all audio streams.

           For each stream, the last matching "c" option is applied, so

                   ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT

           will copy all the streams except the second video, which will be encoded with libx264, and the 138th audio, which will
           be encoded with libvorbis.

       -t duration (input/output)
           When used as an input option (before "-i"), limit the duration of data read from the input file.

           When used as an output option (before an output url), stop writing the output after its duration reaches duration.

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

           -to and -t are mutually exclusive and -t has priority.

       -to position (input/output)
           Stop writing the output or reading the input at position.  position must be a time duration specification, see the Time
           duration section in the ffmpeg-utils(1) manual.

           -to and -t are mutually exclusive and -t has priority.

       -fs limit_size (output)
           Set the file size limit, expressed in bytes. No further chunk of bytes is written after the limit is exceeded. The size
           of the output file is slightly more than the requested file size.

       -ss position (input/output)
           When used as an input option (before "-i"), seeks in this input file to position. Note that in most formats it is not
           possible to seek exactly, so ffmpeg will seek to the closest seek point before position.  When transcoding and
           -accurate_seek is enabled (the default), this extra segment between the seek point and position will be decoded and
           discarded. When doing stream copy or when -noaccurate_seek is used, it will be preserved.

           When used as an output option (before an output url), decodes but discards input until the timestamps reach position.

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

       -sseof position (input)
           Like the "-ss" option but relative to the "end of file". That is negative values are earlier in the file, 0 is at EOF.

       -isync input_index (input)
           Assign an input as a sync source.

           This will take the difference between the start times of the target and reference inputs and offset the timestamps of
           the target file by that difference. The source timestamps of the two inputs should derive from the same clock source
           for expected results. If "copyts" is set then "start_at_zero" must also be set. If either of the inputs has no starting
           timestamp then no sync adjustment is made.

           Acceptable values are those that refer to a valid ffmpeg input index. If the sync reference is the target index itself
           or -1, then no adjustment is made to target timestamps. A sync reference may not itself be synced to any other input.

           Default value is -1.

       -itsoffset offset (input)
           Set the input time offset.

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

           The offset is added to the timestamps of the input files. Specifying a positive offset means that the corresponding
           streams are delayed by the time duration specified in offset.

       -itsscale scale (input,per-stream)
           Rescale input timestamps. scale should be a floating point number.

       -timestamp date (output)
           Set the recording timestamp in the container.

           date must be a date specification, see the Date section in the ffmpeg-utils(1) manual.

       -metadata[:metadata_specifier] key=value (output,per-metadata)
           Set a metadata key/value pair.

           An optional metadata_specifier may be given to set metadata on streams, chapters or programs. See "-map_metadata"
           documentation for details.

           This option overrides metadata set with "-map_metadata". It is also possible to delete metadata by using an empty
           value.

           For example, for setting the title in the output file:

                   ffmpeg -i in.avi -metadata title="my title" out.flv

           To set the language of the first audio stream:

                   ffmpeg -i INPUT -metadata:s:a:0 language=eng OUTPUT

       -disposition[:stream_specifier] value (output,per-stream)
           Sets the disposition for a stream.

           By default, the disposition is copied from the input stream, unless the output stream this option applies to is fed by
           a complex filtergraph - in that case the disposition is unset by default.

           value is a sequence of items separated by '+' or '-'. The first item may also be prefixed with '+' or '-', in which
           case this option modifies the default value. Otherwise (the first item is not prefixed) this options overrides the
           default value. A '+' prefix adds the given disposition, '-' removes it. It is also possible to clear the disposition by
           setting it to 0.

           If no "-disposition" options were specified for an output file, ffmpeg will automatically set the 'default' disposition
           on the first stream of each type, when there are multiple streams of this type in the output file and no stream of that
           type is already marked as default.

           The "-dispositions" option lists the known dispositions.

           For example, to make the second audio stream the default stream:

                   ffmpeg -i in.mkv -c copy -disposition:a:1 default out.mkv

           To make the second subtitle stream the default stream and remove the default disposition from the first subtitle
           stream:

                   ffmpeg -i in.mkv -c copy -disposition:s:0 0 -disposition:s:1 default out.mkv

           To add an embedded cover/thumbnail:

                   ffmpeg -i in.mp4 -i IMAGE -map 0 -map 1 -c copy -c:v:1 png -disposition:v:1 attached_pic out.mp4

           Not all muxers support embedded thumbnails, and those who do, only support a few formats, like JPEG or PNG.

       -program [title=title:][program_num=program_num:]st=stream[:st=stream...] (output)
           Creates a program with the specified title, program_num and adds the specified stream(s) to it.

       -target type (output)
           Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50"). type may be prefixed with "pal-", "ntsc-" or "film-" to
           use the corresponding standard. All the format options (bitrate, codecs, buffer sizes) are then set automatically. You
           can just type:

                   ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg

           Nevertheless you can specify additional options as long as you know they do not conflict with the standard, as in:

                   ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg

           The parameters set for each target are as follows.

           VCD

                   <pal>:
                   -f vcd -muxrate 1411200 -muxpreload 0.44 -packetsize 2324
                   -s 352x288 -r 25
                   -codec:v mpeg1video -g 15 -b:v 1150k -maxrate:v 1150k -minrate:v 1150k -bufsize:v 327680
                   -ar 44100 -ac 2
                   -codec:a mp2 -b:a 224k

                   <ntsc>:
                   -f vcd -muxrate 1411200 -muxpreload 0.44 -packetsize 2324
                   -s 352x240 -r 30000/1001
                   -codec:v mpeg1video -g 18 -b:v 1150k -maxrate:v 1150k -minrate:v 1150k -bufsize:v 327680
                   -ar 44100 -ac 2
                   -codec:a mp2 -b:a 224k

                   <film>:
                   -f vcd -muxrate 1411200 -muxpreload 0.44 -packetsize 2324
                   -s 352x240 -r 24000/1001
                   -codec:v mpeg1video -g 18 -b:v 1150k -maxrate:v 1150k -minrate:v 1150k -bufsize:v 327680
                   -ar 44100 -ac 2
                   -codec:a mp2 -b:a 224k

           SVCD

                   <pal>:
                   -f svcd -packetsize 2324
                   -s 480x576 -pix_fmt yuv420p -r 25
                   -codec:v mpeg2video -g 15 -b:v 2040k -maxrate:v 2516k -minrate:v 0 -bufsize:v 1835008 -scan_offset 1
                   -ar 44100
                   -codec:a mp2 -b:a 224k

                   <ntsc>:
                   -f svcd -packetsize 2324
                   -s 480x480 -pix_fmt yuv420p -r 30000/1001
                   -codec:v mpeg2video -g 18 -b:v 2040k -maxrate:v 2516k -minrate:v 0 -bufsize:v 1835008 -scan_offset 1
                   -ar 44100
                   -codec:a mp2 -b:a 224k

                   <film>:
                   -f svcd -packetsize 2324
                   -s 480x480 -pix_fmt yuv420p -r 24000/1001
                   -codec:v mpeg2video -g 18 -b:v 2040k -maxrate:v 2516k -minrate:v 0 -bufsize:v 1835008 -scan_offset 1
                   -ar 44100
                   -codec:a mp2 -b:a 224k

           DVD

                   <pal>:
                   -f dvd -muxrate 10080k -packetsize 2048
                   -s 720x576 -pix_fmt yuv420p -r 25
                   -codec:v mpeg2video -g 15 -b:v 6000k -maxrate:v 9000k -minrate:v 0 -bufsize:v 1835008
                   -ar 48000
                   -codec:a ac3 -b:a 448k

                   <ntsc>:
                   -f dvd -muxrate 10080k -packetsize 2048
                   -s 720x480 -pix_fmt yuv420p -r 30000/1001
                   -codec:v mpeg2video -g 18 -b:v 6000k -maxrate:v 9000k -minrate:v 0 -bufsize:v 1835008
                   -ar 48000
                   -codec:a ac3 -b:a 448k

                   <film>:
                   -f dvd -muxrate 10080k -packetsize 2048
                   -s 720x480 -pix_fmt yuv420p -r 24000/1001
                   -codec:v mpeg2video -g 18 -b:v 6000k -maxrate:v 9000k -minrate:v 0 -bufsize:v 1835008
                   -ar 48000
                   -codec:a ac3 -b:a 448k

           DV

                   <pal>:
                   -f dv
                   -s 720x576 -pix_fmt yuv420p -r 25
                   -ar 48000 -ac 2

                   <ntsc>:
                   -f dv
                   -s 720x480 -pix_fmt yuv411p -r 30000/1001
                   -ar 48000 -ac 2

                   <film>:
                   -f dv
                   -s 720x480 -pix_fmt yuv411p -r 24000/1001
                   -ar 48000 -ac 2

           The "dv50" target is identical to the "dv" target except that the pixel format set is "yuv422p" for all three
           standards.

           Any user-set value for a parameter above will override the target preset value. In that case, the output may not comply
           with the target standard.

       -dn (input/output)
           As an input option, blocks all data streams of a file from being filtered or being automatically selected or mapped for
           any output. See "-discard" option to disable streams individually.

           As an output option, disables data recording i.e. automatic selection or mapping of any data stream. For full manual
           control see the "-map" option.

       -dframes number (output)
           Set the number of data frames to output. This is an obsolete alias for "-frames:d", which you should use instead.

       -frames[:stream_specifier] framecount (output,per-stream)
           Stop writing to the stream after framecount frames.

       -q[:stream_specifier] q (output,per-stream)
       -qscale[:stream_specifier] q (output,per-stream)
           Use fixed quality scale (VBR). The meaning of q/qscale is codec-dependent.  If qscale is used without a
           stream_specifier then it applies only to the video stream, this is to maintain compatibility with previous behavior and
           as specifying the same codec specific value to 2 different codecs that is audio and video generally is not what is
           intended when no stream_specifier is used.

       -filter[:stream_specifier] filtergraph (output,per-stream)
           Create the filtergraph specified by filtergraph and use it to filter the stream.

           filtergraph is a description of the filtergraph to apply to the stream, and must have a single input and a single
           output of the same type of the stream. In the filtergraph, the input is associated to the label "in", and the output to
           the label "out". See the ffmpeg-filters manual for more information about the filtergraph syntax.

           See the -filter_complex option if you want to create filtergraphs with multiple inputs and/or outputs.

       -filter_script[:stream_specifier] filename (output,per-stream)
           This option is similar to -filter, the only difference is that its argument is the name of the file from which a
           filtergraph description is to be read.

       -reinit_filter[:stream_specifier] integer (input,per-stream)
           This boolean option determines if the filtergraph(s) to which this stream is fed gets reinitialized when input frame
           parameters change mid-stream. This option is enabled by default as most video and all audio filters cannot handle
           deviation in input frame properties.  Upon reinitialization, existing filter state is lost, like e.g. the frame count
           "n" reference available in some filters. Any frames buffered at time of reinitialization are lost.  The properties
           where a change triggers reinitialization are, for video, frame resolution or pixel format; for audio, sample format,
           sample rate, channel count or channel layout.

       -filter_threads nb_threads (global)
           Defines how many threads are used to process a filter pipeline. Each pipeline will produce a thread pool with this many
           threads available for parallel processing.  The default is the number of available CPUs.

       -pre[:stream_specifier] preset_name (output,per-stream)
           Specify the preset for matching stream(s).

       -stats (global)
           Print encoding progress/statistics. It is on by default, to explicitly disable it you need to specify "-nostats".

       -stats_period time (global)
           Set period at which encoding progress/statistics are updated. Default is 0.5 seconds.

       -progress url (global)
           Send program-friendly progress information to url.

           Progress information is written periodically and at the end of the encoding process. It is made of "key=value" lines.
           key consists of only alphanumeric characters. The last key of a sequence of progress information is always "progress".

           The update period is set using "-stats_period".

       -stdin
           Enable interaction on standard input. On by default unless standard input is used as an input. To explicitly disable
           interaction you need to specify "-nostdin".

           Disabling interaction on standard input is useful, for example, if ffmpeg is in the background process group. Roughly
           the same result can be achieved with "ffmpeg ... < /dev/null" but it requires a shell.

       -debug_ts (global)
           Print timestamp information. It is off by default. This option is mostly useful for testing and debugging purposes, and
           the output format may change from one version to another, so it should not be employed by portable scripts.

           See also the option "-fdebug ts".

       -attach filename (output)
           Add an attachment to the output file. This is supported by a few formats like Matroska for e.g. fonts used in rendering
           subtitles. Attachments are implemented as a specific type of stream, so this option will add a new stream to the file.
           It is then possible to use per-stream options on this stream in the usual way. Attachment streams created with this
           option will be created after all the other streams (i.e. those created with "-map" or automatic mappings).

           Note that for Matroska you also have to set the mimetype metadata tag:

                   ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv

           (assuming that the attachment stream will be third in the output file).

       -dump_attachment[:stream_specifier] filename (input,per-stream)
           Extract the matching attachment stream into a file named filename. If filename is empty, then the value of the
           "filename" metadata tag will be used.

           E.g. to extract the first attachment to a file named 'out.ttf':

                   ffmpeg -dump_attachment:t:0 out.ttf -i INPUT

           To extract all attachments to files determined by the "filename" tag:

                   ffmpeg -dump_attachment:t "" -i INPUT

           Technical note -- attachments are implemented as codec extradata, so this option can actually be used to extract
           extradata from any stream, not just attachments.

   Video Options
       -vframes number (output)
           Set the number of video frames to output. This is an obsolete alias for "-frames:v", which you should use instead.

       -r[:stream_specifier] fps (input/output,per-stream)
           Set frame rate (Hz value, fraction or abbreviation).

           As an input option, ignore any timestamps stored in the file and instead generate timestamps assuming constant frame
           rate fps.  This is not the same as the -framerate option used for some input formats like image2 or v4l2 (it used to be
           the same in older versions of FFmpeg).  If in doubt use -framerate instead of the input option -r.

           As an output option, duplicate or drop input frames to achieve constant output frame rate fps.

       -fpsmax[:stream_specifier] fps (output,per-stream)
           Set maximum frame rate (Hz value, fraction or abbreviation).

           Clamps output frame rate when output framerate is auto-set and is higher than this value.  Useful in batch processing
           or when input framerate is wrongly detected as very high.  It cannot be set together with "-r". It is ignored during
           streamcopy.

       -s[:stream_specifier] size (input/output,per-stream)
           Set frame size.

           As an input option, this is a shortcut for the video_size private option, recognized by some demuxers for which the
           frame size is either not stored in the file or is configurable -- e.g. raw video or video grabbers.

           As an output option, this inserts the "scale" video filter to the end of the corresponding filtergraph. Please use the
           "scale" filter directly to insert it at the beginning or some other place.

           The format is wxh (default - same as source).

       -aspect[:stream_specifier] aspect (output,per-stream)
           Set the video display aspect ratio specified by aspect.

           aspect can be a floating point number string, or a string of the form num:den, where num and den are the numerator and
           denominator of the aspect ratio. For example "4:3", "16:9", "1.3333", and "1.7777" are valid argument values.

           If used together with -vcodec copy, it will affect the aspect ratio stored at container level, but not the aspect ratio
           stored in encoded frames, if it exists.

       -vn (input/output)
           As an input option, blocks all video streams of a file from being filtered or being automatically selected or mapped
           for any output. See "-discard" option to disable streams individually.

           As an output option, disables video recording i.e. automatic selection or mapping of any video stream. For full manual
           control see the "-map" option.

       -vcodec codec (output)
           Set the video codec. This is an alias for "-codec:v".

       -pass[:stream_specifier] n (output,per-stream)
           Select the pass number (1 or 2). It is used to do two-pass video encoding. The statistics of the video are recorded in
           the first pass into a log file (see also the option -passlogfile), and in the second pass that log file is used to
           generate the video at the exact requested bitrate.  On pass 1, you may just deactivate audio and set output to null,
           examples for Windows and Unix:

                   ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
                   ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null

       -passlogfile[:stream_specifier] prefix (output,per-stream)
           Set two-pass log file name prefix to prefix, the default file name prefix is ``ffmpeg2pass''. The complete file name
           will be PREFIX-N.log, where N is a number specific to the output stream

       -vf filtergraph (output)
           Create the filtergraph specified by filtergraph and use it to filter the stream.

           This is an alias for "-filter:v", see the -filter option.

       -autorotate
           Automatically rotate the video according to file metadata. Enabled by default, use -noautorotate to disable it.

       -autoscale
           Automatically scale the video according to the resolution of first frame.  Enabled by default, use -noautoscale to
           disable it. When autoscale is disabled, all output frames of filter graph might not be in the same resolution and may
           be inadequate for some encoder/muxer. Therefore, it is not recommended to disable it unless you really know what you
           are doing.  Disable autoscale at your own risk.

   Advanced Video options
       -pix_fmt[:stream_specifier] format (input/output,per-stream)
           Set pixel format. Use "-pix_fmts" to show all the supported pixel formats.  If the selected pixel format can not be
           selected, ffmpeg will print a warning and select the best pixel format supported by the encoder.  If pix_fmt is
           prefixed by a "+", ffmpeg will exit with an error if the requested pixel format can not be selected, and automatic
           conversions inside filtergraphs are disabled.  If pix_fmt is a single "+", ffmpeg selects the same pixel format as the
           input (or graph output) and automatic conversions are disabled.

       -sws_flags flags (input/output)
           Set SwScaler flags.

       -rc_override[:stream_specifier] override (output,per-stream)
           Rate control override for specific intervals, formatted as "int,int,int" list separated with slashes. Two first values
           are the beginning and end frame numbers, last one is quantizer to use if positive, or quality factor if negative.

       -ilme
           Force interlacing support in encoder (MPEG-2 and MPEG-4 only).  Use this option if your input file is interlaced and
           you want to keep the interlaced format for minimum losses.  The alternative is to deinterlace the input stream by use
           of a filter such as "yadif" or "bwdif", but deinterlacing introduces losses.

       -psnr
           Calculate PSNR of compressed frames.

       -vstats
           Dump video coding statistics to vstats_HHMMSS.log.

       -vstats_file file
           Dump video coding statistics to file.

       -vstats_version file
           Specifies which version of the vstats format to use. Default is 2.

           version = 1 :

           "frame= %5d q= %2.1f PSNR= %6.2f f_size= %6d s_size= %8.0fkB time= %0.3f br= %7.1fkbits/s avg_br= %7.1fkbits/s"

           version > 1:

           "out= %2d st= %2d frame= %5d q= %2.1f PSNR= %6.2f f_size= %6d s_size= %8.0fkB time= %0.3f br= %7.1fkbits/s avg_br=
           %7.1fkbits/s"

       -top[:stream_specifier] n (output,per-stream)
           top=1/bottom=0/auto=-1 field first

       -dc precision
           Intra_dc_precision.

       -vtag fourcc/tag (output)
           Force video tag/fourcc. This is an alias for "-tag:v".

       -qphist (global)
           Show QP histogram

       -vbsf bitstream_filter
           Deprecated see -bsf

       -force_key_frames[:stream_specifier] time[,time...] (output,per-stream)
       -force_key_frames[:stream_specifier] expr:expr (output,per-stream)
       -force_key_frames[:stream_specifier] source (output,per-stream)
       -force_key_frames[:stream_specifier] source_no_drop (output,per-stream)
           force_key_frames can take arguments of the following form:

           time[,time...]
               If the argument consists of timestamps, ffmpeg will round the specified times to the nearest output timestamp as
               per the encoder time base and force a keyframe at the first frame having timestamp equal or greater than the
               computed timestamp. Note that if the encoder time base is too coarse, then the keyframes may be forced on frames
               with timestamps lower than the specified time.  The default encoder time base is the inverse of the output
               framerate but may be set otherwise via "-enc_time_base".

               If one of the times is ""chapters"[delta]", it is expanded into the time of the beginning of all chapters in the
               file, shifted by delta, expressed as a time in seconds.  This option can be useful to ensure that a seek point is
               present at a chapter mark or any other designated place in the output file.

               For example, to insert a key frame at 5 minutes, plus key frames 0.1 second before the beginning of every chapter:

                       -force_key_frames 0:05:00,chapters-0.1

           expr:expr
               If the argument is prefixed with "expr:", the string expr is interpreted like an expression and is evaluated for
               each frame. A key frame is forced in case the evaluation is non-zero.

               The expression in expr can contain the following constants:

               n   the number of current processed frame, starting from 0

               n_forced
                   the number of forced frames

               prev_forced_n
                   the number of the previous forced frame, it is "NAN" when no keyframe was forced yet

               prev_forced_t
                   the time of the previous forced frame, it is "NAN" when no keyframe was forced yet

               t   the time of the current processed frame

               For example to force a key frame every 5 seconds, you can specify:

                       -force_key_frames expr:gte(t,n_forced*5)

               To force a key frame 5 seconds after the time of the last forced one, starting from second 13:

                       -force_key_frames expr:if(isnan(prev_forced_t),gte(t,13),gte(t,prev_forced_t+5))

           source
               If the argument is "source", ffmpeg will force a key frame if the current frame being encoded is marked as a key
               frame in its source.

           source_no_drop
               If the argument is "source_no_drop", ffmpeg will force a key frame if the current frame being encoded is marked as
               a key frame in its source.  In cases where this particular source frame has to be dropped, enforce the next
               available frame to become a key frame instead.

           Note that forcing too many keyframes is very harmful for the lookahead algorithms of certain encoders: using fixed-GOP
           options or similar would be more efficient.

       -copyinkf[:stream_specifier] (output,per-stream)
           When doing stream copy, copy also non-key frames found at the beginning.

       -init_hw_device type[=name][:device[,key=value...]]
           Initialise a new hardware device of type type called name, using the given device parameters.  If no name is specified
           it will receive a default name of the form "type%d".

           The meaning of device and the following arguments depends on the device type:

           cuda
               device is the number of the CUDA device.

               The following options are recognized:

               primary_ctx
                   If set to 1, uses the primary device context instead of creating a new one.

               Examples:

               -init_hw_device cuda:1
                   Choose the second device on the system.

               -init_hw_device cuda:0,primary_ctx=1
                   Choose the first device and use the primary device context.

           dxva2
               device is the number of the Direct3D 9 display adapter.

           d3d11va
               device is the number of the Direct3D 11 display adapter.

           vaapi
               device is either an X11 display name or a DRM render node.  If not specified, it will attempt to open the default
               X11 display ($DISPLAY) and then the first DRM render node (/dev/dri/renderD128).

           vdpau
               device is an X11 display name.  If not specified, it will attempt to open the default X11 display ($DISPLAY).

           qsv device selects a value in MFX_IMPL_*. Allowed values are:

               auto
               sw
               hw
               auto_any
               hw_any
               hw2
               hw3
               hw4

               If not specified, auto_any is used.  (Note that it may be easier to achieve the desired result for QSV by creating
               the platform-appropriate subdevice (dxva2 or d3d11va or vaapi) and then deriving a QSV device from that.)

               Alternatively, child_device_type helps to choose platform-appropriate subdevice type.  On Windows d3d11va is used
               as default subdevice type.

               Examples:

               -init_hw_device qsv:hw,child_device_type=d3d11va
                   Choose the GPU subdevice with type d3d11va and create QSV device with MFX_IMPL_HARDWARE.

               -init_hw_device qsv:hw,child_device_type=dxva2
                   Choose the GPU subdevice with type dxva2 and create QSV device with MFX_IMPL_HARDWARE.

           opencl
               device selects the platform and device as platform_index.device_index.

               The set of devices can also be filtered using the key-value pairs to find only devices matching particular platform
               or device strings.

               The strings usable as filters are:

               platform_profile
               platform_version
               platform_name
               platform_vendor
               platform_extensions
               device_name
               device_vendor
               driver_version
               device_version
               device_profile
               device_extensions
               device_type

               The indices and filters must together uniquely select a device.

               Examples:

               -init_hw_device opencl:0.1
                   Choose the second device on the first platform.

               -init_hw_device opencl:,device_name=Foo9000
                   Choose the device with a name containing the string Foo9000.

               -init_hw_device opencl:1,device_type=gpu,device_extensions=cl_khr_fp16
                   Choose the GPU device on the second platform supporting the cl_khr_fp16 extension.

           vulkan
               If device is an integer, it selects the device by its index in a system-dependent list of devices.  If device is
               any other string, it selects the first device with a name containing that string as a substring.

               The following options are recognized:

               debug
                   If set to 1, enables the validation layer, if installed.

               linear_images
                   If set to 1, images allocated by the hwcontext will be linear and locally mappable.

               instance_extensions
                   A plus separated list of additional instance extensions to enable.

               device_extensions
                   A plus separated list of additional device extensions to enable.

               Examples:

               -init_hw_device vulkan:1
                   Choose the second device on the system.

               -init_hw_device vulkan:RADV
                   Choose the first device with a name containing the string RADV.

               -init_hw_device vulkan:0,instance_extensions=VK_KHR_wayland_surface+VK_KHR_xcb_surface
                   Choose the first device and enable the Wayland and XCB instance extensions.

       -init_hw_device type[=name]@source
           Initialise a new hardware device of type type called name, deriving it from the existing device with the name source.

       -init_hw_device list
           List all hardware device types supported in this build of ffmpeg.

       -filter_hw_device name
           Pass the hardware device called name to all filters in any filter graph.  This can be used to set the device to upload
           to with the "hwupload" filter, or the device to map to with the "hwmap" filter.  Other filters may also make use of
           this parameter when they require a hardware device.  Note that this is typically only required when the input is not
           already in hardware frames - when it is, filters will derive the device they require from the context of the frames
           they receive as input.

           This is a global setting, so all filters will receive the same device.

       -hwaccel[:stream_specifier] hwaccel (input,per-stream)
           Use hardware acceleration to decode the matching stream(s). The allowed values of hwaccel are:

           none
               Do not use any hardware acceleration (the default).

           auto
               Automatically select the hardware acceleration method.

           vdpau
               Use VDPAU (Video Decode and Presentation API for Unix) hardware acceleration.

           dxva2
               Use DXVA2 (DirectX Video Acceleration) hardware acceleration.

           d3d11va
               Use D3D11VA (DirectX Video Acceleration) hardware acceleration.

           vaapi
               Use VAAPI (Video Acceleration API) hardware acceleration.

           qsv Use the Intel QuickSync Video acceleration for video transcoding.

               Unlike most other values, this option does not enable accelerated decoding (that is used automatically whenever a
               qsv decoder is selected), but accelerated transcoding, without copying the frames into the system memory.

               For it to work, both the decoder and the encoder must support QSV acceleration and no filters must be used.

           This option has no effect if the selected hwaccel is not available or not supported by the chosen decoder.

           Note that most acceleration methods are intended for playback and will not be faster than software decoding on modern
           CPUs. Additionally, ffmpeg will usually need to copy the decoded frames from the GPU memory into the system memory,
           resulting in further performance loss. This option is thus mainly useful for testing.

       -hwaccel_device[:stream_specifier] hwaccel_device (input,per-stream)
           Select a device to use for hardware acceleration.

           This option only makes sense when the -hwaccel option is also specified.  It can either refer to an existing device
           created with -init_hw_device by name, or it can create a new device as if -init_hw_device type:hwaccel_device were
           called immediately before.

       -hwaccels
           List all hardware acceleration components enabled in this build of ffmpeg.  Actual runtime availability depends on the
           hardware and its suitable driver being installed.

   Audio Options
       -aframes number (output)
           Set the number of audio frames to output. This is an obsolete alias for "-frames:a", which you should use instead.

       -ar[:stream_specifier] freq (input/output,per-stream)
           Set the audio sampling frequency. For output streams it is set by default to the frequency of the corresponding input
           stream. For input streams this option only makes sense for audio grabbing devices and raw demuxers and is mapped to the
           corresponding demuxer options.

       -aq q (output)
           Set the audio quality (codec-specific, VBR). This is an alias for -q:a.

       -ac[:stream_specifier] channels (input/output,per-stream)
           Set the number of audio channels. For output streams it is set by default to the number of input audio channels. For
           input streams this option only makes sense for audio grabbing devices and raw demuxers and is mapped to the
           corresponding demuxer options.

       -an (input/output)
           As an input option, blocks all audio streams of a file from being filtered or being automatically selected or mapped
           for any output. See "-discard" option to disable streams individually.

           As an output option, disables audio recording i.e. automatic selection or mapping of any audio stream. For full manual
           control see the "-map" option.

       -acodec codec (input/output)
           Set the audio codec. This is an alias for "-codec:a".

       -sample_fmt[:stream_specifier] sample_fmt (output,per-stream)
           Set the audio sample format. Use "-sample_fmts" to get a list of supported sample formats.

       -af filtergraph (output)
           Create the filtergraph specified by filtergraph and use it to filter the stream.

           This is an alias for "-filter:a", see the -filter option.

   Advanced Audio options
       -atag fourcc/tag (output)
           Force audio tag/fourcc. This is an alias for "-tag:a".

       -absf bitstream_filter
           Deprecated, see -bsf

       -guess_layout_max channels (input,per-stream)
           If some input channel layout is not known, try to guess only if it corresponds to at most the specified number of
           channels. For example, 2 tells to ffmpeg to recognize 1 channel as mono and 2 channels as stereo but not 6 channels as
           5.1. The default is to always try to guess. Use 0 to disable all guessing.

   Subtitle options
       -scodec codec (input/output)
           Set the subtitle codec. This is an alias for "-codec:s".

       -sn (input/output)
           As an input option, blocks all subtitle streams of a file from being filtered or being automatically selected or mapped
           for any output. See "-discard" option to disable streams individually.

           As an output option, disables subtitle recording i.e. automatic selection or mapping of any subtitle stream. For full
           manual control see the "-map" option.

       -sbsf bitstream_filter
           Deprecated, see -bsf

   Advanced Subtitle options
       -fix_sub_duration
           Fix subtitles durations. For each subtitle, wait for the next packet in the same stream and adjust the duration of the
           first to avoid overlap. This is necessary with some subtitles codecs, especially DVB subtitles, because the duration in
           the original packet is only a rough estimate and the end is actually marked by an empty subtitle frame. Failing to use
           this option when necessary can result in exaggerated durations or muxing failures due to non-monotonic timestamps.

           Note that this option will delay the output of all data until the next subtitle packet is decoded: it may increase
           memory consumption and latency a lot.

       -canvas_size size
           Set the size of the canvas used to render subtitles.

   Advanced options
       -map [-]input_file_id[:stream_specifier][?][,sync_file_id[:stream_specifier]] | [linklabel] (output)
           Designate one or more input streams as a source for the output file. Each input stream is identified by the input file
           index input_file_id and the input stream index input_stream_id within the input file. Both indices start at 0. If
           specified, sync_file_id:stream_specifier sets which input stream is used as a presentation sync reference.

           The first "-map" option on the command line specifies the source for output stream 0, the second "-map" option
           specifies the source for output stream 1, etc.

           A "-" character before the stream identifier creates a "negative" mapping.  It disables matching streams from already
           created mappings.

           A trailing "?" after the stream index will allow the map to be optional: if the map matches no streams the map will be
           ignored instead of failing. Note the map will still fail if an invalid input file index is used; such as if the map
           refers to a non-existent input.

           An alternative [linklabel] form will map outputs from complex filter graphs (see the -filter_complex option) to the
           output file.  linklabel must correspond to a defined output link label in the graph.

           For example, to map ALL streams from the first input file to output

                   ffmpeg -i INPUT -map 0 output

           For example, if you have two audio streams in the first input file, these streams are identified by "0:0" and "0:1".
           You can use "-map" to select which streams to place in an output file. For example:

                   ffmpeg -i INPUT -map 0:1 out.wav

           will map the input stream in INPUT identified by "0:1" to the (single) output stream in out.wav.

           For example, to select the stream with index 2 from input file a.mov (specified by the identifier "0:2"), and stream
           with index 6 from input b.mov (specified by the identifier "1:6"), and copy them to the output file out.mov:

                   ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov

           To select all video and the third audio stream from an input file:

                   ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT

           To map all the streams except the second audio, use negative mappings

                   ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT

           To map the video and audio streams from the first input, and using the trailing "?", ignore the audio mapping if no
           audio streams exist in the first input:

                   ffmpeg -i INPUT -map 0:v -map 0:a? OUTPUT

           To pick the English audio stream:

                   ffmpeg -i INPUT -map 0:m:language:eng OUTPUT

           Note that using this option disables the default mappings for this output file.

       -ignore_unknown
           Ignore input streams with unknown type instead of failing if copying such streams is attempted.

       -copy_unknown
           Allow input streams with unknown type to be copied instead of failing if copying such streams is attempted.

       -map_channel [input_file_id.stream_specifier.channel_id|-1][?][:output_file_id.stream_specifier]
           Map an audio channel from a given input to an output. If output_file_id.stream_specifier is not set, the audio channel
           will be mapped on all the audio streams.

           Using "-1" instead of input_file_id.stream_specifier.channel_id will map a muted channel.

           A trailing "?" will allow the map_channel to be optional: if the map_channel matches no channel the map_channel will be
           ignored instead of failing.

           For example, assuming INPUT is a stereo audio file, you can switch the two audio channels with the following command:

                   ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT

           If you want to mute the first channel and keep the second:

                   ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT

           The order of the "-map_channel" option specifies the order of the channels in the output stream. The output channel
           layout is guessed from the number of channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac" in
           combination of "-map_channel" makes the channel gain levels to be updated if input and output channel layouts don't
           match (for instance two "-map_channel" options and "-ac 6").

           You can also extract each channel of an input to specific outputs; the following command extracts two channels of the
           INPUT audio stream (file 0, stream 0) to the respective OUTPUT_CH0 and OUTPUT_CH1 outputs:

                   ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1

           The following example splits the channels of a stereo input into two separate streams, which are put into the same
           output file:

                   ffmpeg -i stereo.wav -map 0:0 -map 0:0 -map_channel 0.0.0:0.0 -map_channel 0.0.1:0.1 -y out.ogg

           Note that currently each output stream can only contain channels from a single input stream; you can't for example use
           "-map_channel" to pick multiple input audio channels contained in different streams (from the same or different files)
           and merge them into a single output stream. It is therefore not currently possible, for example, to turn two separate
           mono streams into a single stereo stream. However splitting a stereo stream into two single channel mono streams is
           possible.

           If you need this feature, a possible workaround is to use the amerge filter. For example, if you need to merge a media
           (here input.mkv) with 2 mono audio streams into one single stereo channel audio stream (and keep the video stream), you
           can use the following command:

                   ffmpeg -i input.mkv -filter_complex "[0:1] [0:2] amerge" -c:a pcm_s16le -c:v copy output.mkv

           To map the first two audio channels from the first input, and using the trailing "?", ignore the audio channel mapping
           if the first input is mono instead of stereo:

                   ffmpeg -i INPUT -map_channel 0.0.0 -map_channel 0.0.1? OUTPUT

       -map_metadata[:metadata_spec_out] infile[:metadata_spec_in] (output,per-metadata)
           Set metadata information of the next output file from infile. Note that those are file indices (zero-based), not
           filenames.  Optional metadata_spec_in/out parameters specify, which metadata to copy.  A metadata specifier can have
           the following forms:

           g   global metadata, i.e. metadata that applies to the whole file

           s[:stream_spec]
               per-stream metadata. stream_spec is a stream specifier as described in the Stream specifiers chapter. In an input
               metadata specifier, the first matching stream is copied from. In an output metadata specifier, all matching streams
               are copied to.

           c:chapter_index
               per-chapter metadata. chapter_index is the zero-based chapter index.

           p:program_index
               per-program metadata. program_index is the zero-based program index.

           If metadata specifier is omitted, it defaults to global.

           By default, global metadata is copied from the first input file, per-stream and per-chapter metadata is copied along
           with streams/chapters. These default mappings are disabled by creating any mapping of the relevant type. A negative
           file index can be used to create a dummy mapping that just disables automatic copying.

           For example to copy metadata from the first stream of the input file to global metadata of the output file:

                   ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3

           To do the reverse, i.e. copy global metadata to all audio streams:

                   ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv

           Note that simple 0 would work as well in this example, since global metadata is assumed by default.

       -map_chapters input_file_index (output)
           Copy chapters from input file with index input_file_index to the next output file. If no chapter mapping is specified,
           then chapters are copied from the first input file with at least one chapter. Use a negative file index to disable any
           chapter copying.

       -benchmark (global)
           Show benchmarking information at the end of an encode.  Shows real, system and user time used and maximum memory
           consumption.  Maximum memory consumption is not supported on all systems, it will usually display as 0 if not
           supported.

       -benchmark_all (global)
           Show benchmarking information during the encode.  Shows real, system and user time used in various steps (audio/video
           encode/decode).

       -timelimit duration (global)
           Exit after ffmpeg has been running for duration seconds in CPU user time.

       -dump (global)
           Dump each input packet to stderr.

       -hex (global)
           When dumping packets, also dump the payload.

       -readrate speed (input)
           Limit input read speed.

           Its value is a floating-point positive number which represents the maximum duration of media, in seconds, that should
           be ingested in one second of wallclock time.  Default value is zero and represents no imposed limitation on speed of
           ingestion.  Value 1 represents real-time speed and is equivalent to "-re".

           Mainly used to simulate a capture device or live input stream (e.g. when reading from a file).  Should not be used with
           a low value when input is an actual capture device or live stream as it may cause packet loss.

           It is useful for when flow speed of output packets is important, such as live streaming.

       -re (input)
           Read input at native frame rate. This is equivalent to setting "-readrate 1".

       -vsync parameter (global)
       -fps_mode[:stream_specifier] parameter (output,per-stream)
           Set video sync method / framerate mode. vsync is applied to all output video streams but can be overridden for a stream
           by setting fps_mode. vsync is deprecated and will be removed in the future.

           For compatibility reasons some of the values for vsync can be specified as numbers (shown in parentheses in the
           following table).

           passthrough (0)
               Each frame is passed with its timestamp from the demuxer to the muxer.

           cfr (1)
               Frames will be duplicated and dropped to achieve exactly the requested constant frame rate.

           vfr (2)
               Frames are passed through with their timestamp or dropped so as to prevent 2 frames from having the same timestamp.

           drop
               As passthrough but destroys all timestamps, making the muxer generate fresh timestamps based on frame-rate.

           auto (-1)
               Chooses between cfr and vfr depending on muxer capabilities. This is the default method.

           Note that the timestamps may be further modified by the muxer, after this.  For example, in the case that the format
           option avoid_negative_ts is enabled.

           With -map you can select from which stream the timestamps should be taken. You can leave either video or audio
           unchanged and sync the remaining stream(s) to the unchanged one.

       -frame_drop_threshold parameter
           Frame drop threshold, which specifies how much behind video frames can be before they are dropped. In frame rate units,
           so 1.0 is one frame.  The default is -1.1. One possible usecase is to avoid framedrops in case of noisy timestamps or
           to increase frame drop precision in case of exact timestamps.

       -async samples_per_second
           Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps, the parameter is the maximum samples
           per second by which the audio is changed.  -async 1 is a special case where only the start of the audio stream is
           corrected without any later correction.

           Note that the timestamps may be further modified by the muxer, after this.  For example, in the case that the format
           option avoid_negative_ts is enabled.

           This option has been deprecated. Use the "aresample" audio filter instead.

       -adrift_threshold time
           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 (add/drop) and soft
           (squeeze/stretch) compensation.  "-async" must be set to a positive value.

       -apad parameters (output,per-stream)
           Pad the output audio stream(s). This is the same as applying "-af apad".  Argument is a string of filter parameters
           composed the same as with the "apad" filter.  "-shortest" must be set for this output for the option to take effect.

       -copyts
           Do not process input timestamps, but keep their values without trying to sanitize them. In particular, do not remove
           the initial start time offset value.

           Note that, depending on the vsync option or on specific muxer processing (e.g. in case the format option
           avoid_negative_ts is enabled) the output timestamps may mismatch with the input timestamps even when this option is
           selected.

       -start_at_zero
           When used with copyts, shift input timestamps so they start at zero.

           This means that using e.g. "-ss 50" will make output timestamps start at 50 seconds, regardless of what timestamp the
           input file started at.

       -copytb mode
           Specify how to set the encoder timebase when stream copying.  mode is an integer numeric value, and can assume one of
           the following values:

           1   Use the demuxer timebase.

               The time base is copied to the output encoder from the corresponding input demuxer. This is sometimes required to
               avoid non monotonically increasing timestamps when copying video streams with variable frame rate.

           0   Use the decoder timebase.

               The time base is copied to the output encoder from the corresponding input decoder.

           -1  Try to make the choice automatically, in order to generate a sane output.

           Default value is -1.

       -enc_time_base[:stream_specifier] timebase (output,per-stream)
           Set the encoder timebase. timebase is a floating point number, and can assume one of the following values:

           0   Assign a default value according to the media type.

               For video - use 1/framerate, for audio - use 1/samplerate.

           -1  Use the input stream timebase when possible.

               If an input stream is not available, the default timebase will be used.

           >0  Use the provided number as the timebase.

               This field can be provided as a ratio of two integers (e.g. 1:24, 1:48000) or as a floating point number (e.g.
               0.04166, 2.0833e-5)

           Default value is 0.

       -bitexact (input/output)
           Enable bitexact mode for (de)muxer and (de/en)coder

       -shortest (output)
           Finish encoding when the shortest output stream ends.

       -dts_delta_threshold
           Timestamp discontinuity delta threshold.

       -dts_error_threshold seconds
           Timestamp error delta threshold. This threshold use to discard crazy/damaged timestamps and the default is 30 hours
           which is arbitrarily picked and quite conservative.

       -muxdelay seconds (output)
           Set the maximum demux-decode delay.

       -muxpreload seconds (output)
           Set the initial demux-decode delay.

       -streamid output-stream-index:new-value (output)
           Assign a new stream-id value to an output stream. This option should be specified prior to the output filename to which
           it applies.  For the situation where multiple output files exist, a streamid may be reassigned to a different value.

           For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for an output mpegts file:

                   ffmpeg -i inurl -streamid 0:33 -streamid 1:36 out.ts

       -bsf[:stream_specifier] bitstream_filters (output,per-stream)
           Set bitstream filters for matching streams. bitstream_filters is a comma-separated list of bitstream filters. Use the
           "-bsfs" option to get the list of bitstream filters.

                   ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264

                   ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt

       -tag[:stream_specifier] codec_tag (input/output,per-stream)
           Force a tag/fourcc for matching streams.

       -timecode hh:mm:ssSEPff
           Specify Timecode for writing. SEP is ':' for non drop timecode and ';' (or '.') for drop.

                   ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg

       -filter_complex filtergraph (global)
           Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or outputs. For simple graphs -- those with
           one input and one output of the same type -- see the -filter options. filtergraph is a description of the filtergraph,
           as described in the ``Filtergraph syntax'' section of the ffmpeg-filters manual.

           Input link labels must refer to input streams using the "[file_index:stream_specifier]" syntax (i.e. the same as -map
           uses). If stream_specifier matches multiple streams, the first one will be used. An unlabeled input will be connected
           to the first unused input stream of the matching type.

           Output link labels are referred to with -map. Unlabeled outputs are added to the first output file.

           Note that with this option it is possible to use only lavfi sources without normal input files.

           For example, to overlay an image over video

                   ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map
                   '[out]' out.mkv

           Here "[0:v]" refers to the first video stream in the first input file, which is linked to the first (main) input of the
           overlay filter. Similarly the first video stream in the second input is linked to the second (overlay) input of
           overlay.

           Assuming there is only one video stream in each input file, we can omit input labels, so the above is equivalent to

                   ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map
                   '[out]' out.mkv

           Furthermore we can omit the output label and the single output from the filter graph will be added to the output file
           automatically, so we can simply write

                   ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv

           As a special exception, you can use a bitmap subtitle stream as input: it will be converted into a video with the same
           size as the largest video in the file, or 720x576 if no video is present. Note that this is an experimental and
           temporary solution. It will be removed once libavfilter has proper support for subtitles.

           For example, to hardcode subtitles on top of a DVB-T recording stored in MPEG-TS format, delaying the subtitles by 1
           second:

                   ffmpeg -i input.ts -filter_complex \
                     '[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \
                     -sn -map '#0x2dc' output.mkv

           (0x2d0, 0x2dc and 0x2ef are the MPEG-TS PIDs of respectively the video, audio and subtitles streams; 0:0, 0:3 and 0:7
           would have worked too)

           To generate 5 seconds of pure red video using lavfi "color" source:

                   ffmpeg -filter_complex 'color=c=red' -t 5 out.mkv

       -filter_complex_threads nb_threads (global)
           Defines how many threads are used to process a filter_complex graph.  Similar to filter_threads but used for
           "-filter_complex" graphs only.  The default is the number of available CPUs.

       -lavfi filtergraph (global)
           Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or outputs. Equivalent to -filter_complex.

       -filter_complex_script filename (global)
           This option is similar to -filter_complex, the only difference is that its argument is the name of the file from which
           a complex filtergraph description is to be read.

       -accurate_seek (input)
           This option enables or disables accurate seeking in input files with the -ss option. It is enabled by default, so
           seeking is accurate when transcoding. Use -noaccurate_seek to disable it, which may be useful e.g. when copying some
           streams and transcoding the others.

       -seek_timestamp (input)
           This option enables or disables seeking by timestamp in input files with the -ss option. It is disabled by default. If
           enabled, the argument to the -ss option is considered an actual timestamp, and is not offset by the start time of the
           file. This matters only for files which do not start from timestamp 0, such as transport streams.

       -thread_queue_size size (input)
           This option sets the maximum number of queued packets when reading from the file or device. With low latency / high
           rate live streams, packets may be discarded if they are not read in a timely manner; setting this value can force
           ffmpeg to use a separate input thread and read packets as soon as they arrive. By default ffmpeg only does this if
           multiple inputs are specified.

       -sdp_file file (global)
           Print sdp information for an output stream to file.  This allows dumping sdp information when at least one output isn't
           an rtp stream. (Requires at least one of the output formats to be rtp).

       -discard (input)
           Allows discarding specific streams or frames from streams.  Any input stream can be fully discarded, using value "all"
           whereas selective discarding of frames from a stream occurs at the demuxer and is not supported by all demuxers.

           none
               Discard no frame.

           default
               Default, which discards no frames.

           noref
               Discard all non-reference frames.

           bidir
               Discard all bidirectional frames.

           nokey
               Discard all frames excepts keyframes.

           all Discard all frames.

       -abort_on flags (global)
           Stop and abort on various conditions. The following flags are available:

           empty_output
               No packets were passed to the muxer, the output is empty.

           empty_output_stream
               No packets were passed to the muxer in some of the output streams.

       -max_error_rate (global)
           Set fraction of decoding frame failures across all inputs which when crossed ffmpeg will return exit code 69. Crossing
           this threshold does not terminate processing. Range is a floating-point number between 0 to 1. Default is 2/3.

       -xerror (global)
           Stop and exit on error

       -max_muxing_queue_size packets (output,per-stream)
           When transcoding audio and/or video streams, ffmpeg will not begin writing into the output until it has one packet for
           each such stream. While waiting for that to happen, packets for other streams are buffered. This option sets the size
           of this buffer, in packets, for the matching output stream.

           The default value of this option should be high enough for most uses, so only touch this option if you are sure that
           you need it.

       -muxing_queue_data_threshold bytes (output,per-stream)
           This is a minimum threshold until which the muxing queue size is not taken into account. Defaults to 50 megabytes per
           stream, and is based on the overall size of packets passed to the muxer.

       -auto_conversion_filters (global)
           Enable automatically inserting format conversion filters in all filter graphs, including those defined by -vf, -af,
           -filter_complex and -lavfi. If filter format negotiation requires a conversion, the initialization of the filters will
           fail.  Conversions can still be performed by inserting the relevant conversion filter (scale, aresample) in the graph.
           On by default, to explicitly disable it you need to specify "-noauto_conversion_filters".

       -bits_per_raw_sample[:stream_specifier] value (output,per-stream)
           Declare the number of bits per raw sample in the given output stream to be value. Note that this option sets the
           information provided to the encoder/muxer, it does not change the stream to conform to this value. Setting values that
           do not match the stream properties may result in encoding failures or invalid output files.

   Preset files
       A preset file contains a sequence of option=value pairs, one for each line, specifying a sequence of options which would be
       awkward to specify on the command line. Lines starting with the hash ('#') character are ignored and are used to provide
       comments. Check the presets directory in the FFmpeg source tree for examples.

       There are two types of preset files: ffpreset and avpreset files.

       ffpreset files

       ffpreset files are specified with the "vpre", "apre", "spre", and "fpre" options. The "fpre" option takes the filename of
       the preset instead of a preset name as input and can be used for any kind of codec. For the "vpre", "apre", and "spre"
       options, the options specified in a preset file are applied to the currently selected codec of the same type as the preset
       option.

       The argument passed to the "vpre", "apre", and "spre" preset options identifies the preset file to use according to the
       following rules:

       First ffmpeg searches for a file named arg.ffpreset in the directories $FFMPEG_DATADIR (if set), and $HOME/.ffmpeg, and in
       the datadir defined at configuration time (usually PREFIX/share/ffmpeg) or in a ffpresets folder along the executable on
       win32, in that order. For example, if the argument is "libvpx-1080p", it will search for the file libvpx-1080p.ffpreset.

       If no such file is found, then ffmpeg will search for a file named codec_name-arg.ffpreset in the above-mentioned
       directories, where codec_name is the name of the codec to which the preset file options will be applied. For example, if
       you select the video codec with "-vcodec libvpx" and use "-vpre 1080p", then it will search for the file
       libvpx-1080p.ffpreset.

       avpreset files

       avpreset files are specified with the "pre" option. They work similar to ffpreset files, but they only allow encoder-
       specific options. Therefore, an option=value pair specifying an encoder cannot be used.

       When the "pre" option is specified, ffmpeg will look for files with the suffix .avpreset in the directories $AVCONV_DATADIR
       (if set), and $HOME/.avconv, and in the datadir defined at configuration time (usually PREFIX/share/ffmpeg), in that order.

       First ffmpeg searches for a file named codec_name-arg.avpreset in the above-mentioned directories, where codec_name is the
       name of the codec to which the preset file options will be applied. For example, if you select the video codec with
       "-vcodec libvpx" and use "-pre 1080p", then it will search for the file libvpx-1080p.avpreset.

       If no such file is found, then ffmpeg will search for a file named arg.avpreset in the same directories.

EXAMPLES
   Video and Audio grabbing
       If you specify the input format and device then ffmpeg can grab video and audio directly.

               ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg

       Or with an ALSA audio source (mono input, card id 1) instead of OSS:

               ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg

       Note that you must activate the right video source and channel before launching ffmpeg with any TV viewer such as
       <http://linux.bytesex.org/xawtv/> by Gerd Knorr. You also have to set the audio recording levels correctly with a standard
       mixer.

   X11 grabbing
       Grab the X11 display with ffmpeg via

               ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0 /tmp/out.mpg

       0.0 is display.screen number of your X11 server, same as the DISPLAY environment variable.

               ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0+10,20 /tmp/out.mpg

       0.0 is display.screen number of your X11 server, same as the DISPLAY environment variable. 10 is the x-offset and 20 the
       y-offset for the grabbing.

   Video and Audio file format conversion
       Any supported file format and protocol can serve as input to ffmpeg:

       Examples:

       •   You can use YUV files as input:

                   ffmpeg -i /tmp/test%d.Y /tmp/out.mpg

           It will use the files:

                   /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
                   /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...

           The Y files use twice the resolution of the U and V files. They are raw files, without header. They can be generated by
           all decent video decoders. You must specify the size of the image with the -s option if ffmpeg cannot guess it.

       •   You can input from a raw YUV420P file:

                   ffmpeg -i /tmp/test.yuv /tmp/out.avi

           test.yuv is a file containing raw YUV planar data. Each frame is composed of the Y plane followed by the U and V planes
           at half vertical and horizontal resolution.

       •   You can output to a raw YUV420P file:

                   ffmpeg -i mydivx.avi hugefile.yuv

       •   You can set several input files and output files:

                   ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg

           Converts the audio file a.wav and the raw YUV video file a.yuv to MPEG file a.mpg.

       •   You can also do audio and video conversions at the same time:

                   ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2

           Converts a.wav to MPEG audio at 22050 Hz sample rate.

       •   You can encode to several formats at the same time and define a mapping from input stream to output streams:

                   ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2

           Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map file:index' specifies which input stream is used
           for each output stream, in the order of the definition of output streams.

       •   You can transcode decrypted VOBs:

                   ffmpeg -i snatch_1.vob -f avi -c:v mpeg4 -b:v 800k -g 300 -bf 2 -c:a libmp3lame -b:a 128k snatch.avi

           This is a typical DVD ripping example; the input is a VOB file, the output an AVI file with MPEG-4 video and MP3 audio.
           Note that in this command we use B-frames so the MPEG-4 stream is DivX5 compatible, and GOP size is 300 which means one
           intra frame every 10 seconds for 29.97fps input video. Furthermore, the audio stream is MP3-encoded so you need to
           enable LAME support by passing "--enable-libmp3lame" to configure.  The mapping is particularly useful for DVD
           transcoding to get the desired audio language.

           NOTE: To see the supported input formats, use "ffmpeg -demuxers".

       •   You can extract images from a video, or create a video from many images:

           For extracting images from a video:

                   ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg

           This will extract one video frame per second from the video and will output them in files named foo-001.jpeg,
           foo-002.jpeg, etc. Images will be rescaled to fit the new WxH values.

           If you want to extract just a limited number of frames, you can use the above command in combination with the
           "-frames:v" or "-t" option, or in combination with -ss to start extracting from a certain point in time.

           For creating a video from many images:

                   ffmpeg -f image2 -framerate 12 -i foo-%03d.jpeg -s WxH foo.avi

           The syntax "foo-%03d.jpeg" specifies to use a decimal number composed of three digits padded with zeroes to express the
           sequence number. It is the same syntax supported by the C printf function, but only formats accepting a normal integer
           are suitable.

           When importing an image sequence, -i also supports expanding shell-like wildcard patterns (globbing) internally, by
           selecting the image2-specific "-pattern_type glob" option.

           For example, for creating a video from filenames matching the glob pattern "foo-*.jpeg":

                   ffmpeg -f image2 -pattern_type glob -framerate 12 -i 'foo-*.jpeg' -s WxH foo.avi

       •   You can put many streams of the same type in the output:

                   ffmpeg -i test1.avi -i test2.avi -map 1:1 -map 1:0 -map 0:1 -map 0:0 -c copy -y test12.nut

           The resulting output file test12.nut will contain the first four streams from the input files in reverse order.

       •   To force CBR video output:

                   ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v

       •   The four options lmin, lmax, mblmin and mblmax use 'lambda' units, but you may use the QP2LAMBDA constant to easily
           convert from 'q' units:

                   ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext

SEE ALSO
       ffmpeg-all(1), ffplay(1), ffprobe(1), ffmpeg-utils(1), ffmpeg-scaler(1), ffmpeg-resampler(1), ffmpeg-codecs(1),
       ffmpeg-bitstream-filters(1), ffmpeg-formats(1), ffmpeg-devices(1), ffmpeg-protocols(1), ffmpeg-filters(1)

AUTHORS
       The FFmpeg developers.

       For details about the authorship, see the Git history of the project (https://git.ffmpeg.org/ffmpeg), e.g. by typing the
       command git log in the FFmpeg source directory, or browsing the online repository at <https://git.ffmpeg.org/ffmpeg>.

       Maintainers for the specific components are listed in the file MAINTAINERS in the source code tree.

                                                                                                                         FFMPEG(1)