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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 name	filter_name.
	       Use the -filters	option to get a	list of	all filters.

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

       -version
	   Show	version.

       -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.

       -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

   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.

       -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.

       -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.

	   This	option overrides the disposition copied	from the input stream.
	   It is also possible to delete the disposition by setting it to 0.

	   The following dispositions are recognized:

	   default
	   dub
	   original
	   comment
	   lyrics
	   karaoke
	   forced
	   hearing_impaired
	   visual_impaired
	   clean_effects
	   attached_pic
	   captions
	   descriptions
	   dependent
	   metadata

	   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

       -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.

       -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".

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

	   Progress information	is written approximately every second 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".

       -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.

       -noautorotate
	   Disable automatically rotating video	based on file metadata.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

       -ilme
	   Force interlacing support in	encoder	(MPEG-2	and MPEG-4 only).  Use
	   this	option if your input file is interlaced	and you	want to	keep
	   the interlaced format for minimum losses.  The alternative is to
	   deinterlace the input stream	with -deinterlace, but deinterlacing
	   introduces losses.

       -psnr
	   Calculate PSNR of compressed	frames.

       -vstats
	   Dump	video coding statistics	to vstats_HHMMSS.log.

       -vstats_file file
	   Dump	video coding statistics	to file.

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

	   version = 1 :

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

	   version > 1:

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

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

       -dc precision
	   Intra_dc_precision.

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

       -qphist (global)
	   Show	QP histogram

       -vbsf bitstream_filter
	   Deprecated see -bsf

       -force_key_frames[:stream_specifier] time[,time...] (output,per-stream)
       -force_key_frames[:stream_specifier] expr:expr (output,per-stream)
       -force_key_frames[:stream_specifier] source (output,per-stream)
	   force_key_frames 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.

	   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.

	   dxva2
	       device is the number of the Direct3D 9 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	vaapi) and then
	       deriving	a QSV device from that.)

	   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.

	   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 methods supported in this build of
	   ffmpeg.

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

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

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

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

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

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

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

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

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

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

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

       -absf bitstream_filter
	   Deprecated, see -bsf

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

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

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

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

       -sbsf bitstream_filter
	   Deprecated, see -bsf

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

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

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

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

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

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

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

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

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

		   ffmpeg -i INPUT -map	0 output

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

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

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

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

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

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

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

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

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

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

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

	   To pick the English audio stream:

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

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

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

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

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

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

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

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

		   ffmpeg -i INPUT -map_channel	0.0.1 -map_channel 0.0.0 OUTPUT

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	   If metadata specifier is omitted, it	defaults to global.

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

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

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

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

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

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

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

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

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

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

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

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

       -re (input)
	   Read	input at native	frame rate. Mainly used	to simulate a grab
	   device, or live input stream	(e.g. when reading from	a file).
	   Should not be used with actual grab devices or live input streams
	   (where it can cause packet loss).  By default ffmpeg	attempts to
	   read	the input(s) as	fast as	possible.  This	option will slow down
	   the reading of the input(s) to the native frame rate	of the
	   input(s). It	is useful for real-time	output (e.g. live streaming).

       -vsync parameter
	   Video sync method.  For compatibility reasons old values can	be
	   specified as	numbers.  Newly	added values will have to be specified
	   as strings always.

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

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

	   2, vfr
	       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.

	   -1, auto
	       Chooses between 1 and 2 depending on muxer capabilities.	This
	       is the default method.

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

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

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

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

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

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

       -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 input stream ends.

       -dts_delta_threshold
	   Timestamp discontinuity delta threshold.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	   For example,	to overlay an image over video

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

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

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

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

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

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

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

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

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

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

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

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

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

       -thread_queue_size size (input)
	   This	option sets the	maximum	number of queued packets when reading
	   from	the file or device. With low latency / high rate live streams,
	   packets may be discarded if they are	not read in a timely manner;
	   raising this	value can avoid	it.

       -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.

       -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.

       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)

   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)

NAME | SYNOPSIS | DESCRIPTION | DETAILED DESCRIPTION | STREAM SELECTION | OPTIONS | EXAMPLES | SEE ALSO | AUTHORS

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