ffmpeg/bin/manpages/ffmpeg.txt

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.

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

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

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

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

       o   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:

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

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

       o   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:

	   video encoding
	       Duplicate or drop frames right before encoding them to achieve
	       constant output frame rate fps.

	   video streamcopy
	       Indicate to the muxer that fps is the stream frame rate. No
	       data is dropped or duplicated in this case. This may produce
	       invalid files if fps does not match the actual stream frame
	       rate as determined by packet timestamps.  See also the "setts"
	       bitstream filter.

       -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.

       -display_rotation[:stream_specifier] rotation (input,per-stream)
	   Set video rotation metadata.

	   rotation is a decimal number specifying the amount in degree by
	   which the video should be rotated counter-clockwise before being
	   displayed.

	   This option overrides the rotation/display transform metadata
	   stored in the file, if any. When the video is being transcoded
	   (rather than copied) and "-autorotate" is enabled, the video will
	   be rotated at the filtering stage. Otherwise, the metadata will be
	   written into the output file if the muxer supports it.

	   If the "-display_hflip" and/or "-display_vflip" options are given,
	   they are applied after the rotation specified by this option.

       -display_hflip[:stream_specifier] (input,per-stream)
	   Set whether on display the image should be horizontally flipped.

	   See the "-display_rotation" option for more details.

       -display_vflip[:stream_specifier] (input,per-stream)
	   Set whether on display the image should be vertically flipped.

	   See the "-display_rotation" option for more details.

       -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.

       -psnr
	   Calculate PSNR of compressed frames. This option is deprecated,
	   pass the PSNR flag to the encoder instead, using "-flags +psnr".

       -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

       -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.

       -fix_sub_duration_heartbeat[:stream_specifier]
	   Set a specific output video stream as the heartbeat stream
	   according to which to split and push through currently in-progress
	   subtitle upon receipt of a random access packet.

	   This lowers the latency of subtitles for which the end packet or
	   the following subtitle has not yet been received. As a drawback,
	   this will most likely lead to duplication of subtitle events in
	   order to cover the full duration, so when dealing with use cases
	   where latency of when the subtitle event is passed on to output is
	   not relevant this option should not be utilized.

	   Requires -fix_sub_duration to be set for the relevant input
	   subtitle stream for this to have any effect, as well as for the
	   input subtitle stream having to be directly mapped to the same
	   output in which the heartbeat stream resides.

   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][?] | [linklabel] (output)
	   Create one or more streams in the output file. This option has two
	   forms for specifying the data source(s): the first selects one or
	   more streams from some input file (specified with "-i"), the second
	   takes an output from some complex filtergraph (specified with
	   "-filter_complex" or "-filter_complex_script").

	   In the first form, an output stream is created for every stream
	   from the input file with the index input_file_id. If
	   stream_specifier is given, only those streams that match the
	   specifier are used (see the Stream specifiers section for the
	   stream_specifier syntax).

	   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.

	   This option may be specified multiple times, each adding more
	   streams to the output file. Any given input stream may also be
	   mapped any number of times as a source for different output
	   streams, e.g. in order to use different encoding options and/or
	   filters. The streams are created in the output in the same order in
	   which the "-map" options are given on the commandline.

	   Using this option disables the default mappings for this output
	   file.

	   Examples:

	   map everything
	       To map ALL streams from the first input file to output

		       ffmpeg -i INPUT -map 0 output

	   select specific stream
	       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 second input stream in INPUT to the (single)
	       output stream in out.wav.

	   create multiple streams
	       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

	   create multiple streams 2
	       To select all video and the third audio stream from an input
	       file:

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

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

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

	   optional map
	       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

	   map by language
	       To pick the English audio stream:

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

       -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]
	   This option is deprecated and will be removed. It can be replaced
	   by the pan filter. In some cases it may be easier to use some
	   combination of the channelsplit, channelmap, or amerge filters.

	   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.

       -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.

	   Note that this option may require buffering frames, which
	   introduces extra latency. The maximum amount of this latency may be
	   controlled with the "-shortest_buf_duration" option.

       -shortest_buf_duration duration (output)
	   The "-shortest" option may require buffering potentially large
	   amounts of data when at least one of the streams is "sparse" (i.e.
	   has large gaps between frames X this is typically the case for
	   subtitles).

	   This option controls the maximum duration of buffered frames in
	   seconds.  Larger values may allow the "-shortest" option to produce
	   more accurate results, but increase memory use and latency.

	   The default value is 10 seconds.

       -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/output)
	   For 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.

	   For output, this option specified the maximum number of packets
	   that may be queued to each muxing thread.

       -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.

       -stats_enc_pre[:stream_specifier] path (output,per-stream)
       -stats_enc_post[:stream_specifier] path (output,per-stream)
       -stats_mux_pre[:stream_specifier] path (output,per-stream)
	   Write per-frame encoding information about the matching streams
	   into the file given by path.

	   -stats_enc_pre writes information about raw video or audio frames
	   right before they are sent for encoding, while -stats_enc_post
	   writes information about encoded packets as they are received from
	   the encoder.  -stats_mux_pre writes information about packets just
	   as they are about to be sent to the muxer. Every frame or packet
	   produces one line in the specified file. The format of this line is
	   controlled by -stats_enc_pre_fmt / -stats_enc_post_fmt /
	   -stats_mux_pre_fmt.

	   When stats for multiple streams are written into a single file, the
	   lines corresponding to different streams will be interleaved. The
	   precise order of this interleaving is not specified and not
	   guaranteed to remain stable between different invocations of the
	   program, even with the same options.

       -stats_enc_pre_fmt[:stream_specifier] format_spec (output,per-stream)
       -stats_enc_post_fmt[:stream_specifier] format_spec (output,per-stream)
       -stats_mux_pre_fmt[:stream_specifier] format_spec (output,per-stream)
	   Specify the format for the lines written with -stats_enc_pre /
	   -stats_enc_post / -stats_mux_pre.

	   format_spec is a string that may contain directives of the form
	   {fmt}. format_spec is backslash-escaped --- use \{, \}, and \\ to
	   write a literal {, }, or \, respectively, into the output.

	   The directives given with fmt may be one of the following:

	   fidx
	       Index of the output file.

	   sidx
	       Index of the output stream in the file.

	   n   Frame number. Pre-encoding: number of frames sent to the
	       encoder so far.	Post-encoding: number of packets received from
	       the encoder so far.  Muxing: number of packets submitted to the
	       muxer for this stream so far.

	   ni  Input frame number. Index of the input frame (i.e. output by a
	       decoder) that corresponds to this output frame or packet. -1 if
	       unavailable.

	   tb  Encoder timebase, as a rational number num/den. Note that this
	       may be different from the timebase used by the muxer.

	   tbi Timebase for ptsi, as a rational number num/den. Available when
	       ptsi is available, 0/1 otherwise.

	   pts Presentation timestamp of the frame or packet, as an integer.
	       Should be multiplied by the timebase to compute presentation
	       time.

	   ptsi
	       Presentation timestamp of the input frame (see ni), as an
	       integer. Should be multiplied by tbi to compute presentation
	       time. Printed as (2^63 - 1 = 9223372036854775807) when not
	       available.

	   t   Presentation time of the frame or packet, as a decimal number.
	       Equal to pts multiplied by tb.

	   ti  Presentation time of the input frame (see ni), as a decimal
	       number. Equal to ptsi multiplied by tbi. Printed as inf when
	       not available.

	   dts Decoding timestamp of the packet, as an integer. Should be
	       multiplied by the timebase to compute presentation time. Post-
	       encoding only.

	   dt  Decoding time of the frame or packet, as a decimal number.
	       Equal to dts multiplied by tb.

	   sn  Number of audio samples sent to the encoder so far. Audio and
	       pre-encoding only.

	   samp
	       Number of audio samples in the frame. Audio and pre-encoding
	       only.

	   size
	       Size of the encoded packet in bytes. Post-encoding only.

	   br  Current bitrate in bits per second. Post-encoding only.

	   abr Average bitrate for the whole stream so far, in bits per
	       second, -1 if it cannot be determined at this point. Post-
	       encoding only.

	   The default format strings are:

	   pre-encoding
	       {fidx} {sidx} {n} {t}

	   post-encoding
	       {fidx} {sidx} {n} {t}

	   In the future, new items may be added to the end of the default
	   formatting strings. Users who depend on the format staying exactly
	   the same, should prescribe it manually.

	   Note that stats for different streams written into the same file
	   may have different formats.

   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:

       o   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.

       o   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.

       o   You can output to a raw YUV420P file:

		   ffmpeg -i mydivx.avi hugefile.yuv

       o   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.

       o   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.

       o   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.

       o   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".

       o   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

       o   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.

       o   To force CBR video output:

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

       o   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
       (git://source.ffmpeg.org/ffmpeg), e.g. by typing the command git log in
       the FFmpeg source directory, or browsing the online repository at
       <http://source.ffmpeg.org>.

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

								     FFMPEG(1)