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AVPROBE(1)							    AVPROBE(1)

NAME
       avprobe - avprobe media prober

SYNOPSIS
       avprobe [options] [input_file]

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

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

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

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

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

       avprobe output is designed to be	easily parsable	by any INI or JSON
       parsers.

OPTIONS
       All the numerical options, if not specified otherwise, accept in	input
       a string	representing a number, which may contain one of	the SI unit
       prefixes, for example 'K', 'M', 'G'.  If	'i' is appended	after the
       prefix, binary prefixes are used, which are based on powers of 1024
       instead of powers of 1000.  The 'B' postfix multiplies the value	by 8,
       and can be appended after a unit	prefix or used alone. This allows
       using for example 'KB', 'MiB', 'G' and 'B' as number postfix.

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

   Stream specifiers
       Some options are	applied	per-stream, e.g. bitrate or codec. Stream
       specifiers are used to precisely	specify	which stream(s)	does a given
       option belong 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" option contains
       "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 stream, the	option is then 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.

       stream_type[:stream_index]
	   stream_type is one of: 'v' for video, 'a' for audio,	's' for
	   subtitle, 'd' for data and 't' for attachments. If stream_index is
	   given, then matches stream number stream_index of this type.
	   Otherwise matches all streams of this type.

       p:program_id[:stream_index]
	   If stream_index is given, then matches stream number	stream_index
	   in program with id program_id. Otherwise matches all	streams	in
	   this	program.

       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	avconv,	matching by metadata will only work properly
	   for input files.

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

       -L  Show	license.

       -h, -?, -help, --help [arg]
	   Show	help. An optional parameter may	be specified to	print help
	   about a specific item.

	   Possible values of arg are:

	   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.

       -version
	   Show	version.

       -formats
	   Show	available formats.

	   The fields preceding	the format names have the following meanings:

	   D   Decoding	available

	   E   Encoding	available

       -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.

       -loglevel loglevel | -v loglevel
	   Set the logging level used by the library.  loglevel	is a number or
	   a string containing one of the following values:

	   quiet
	   panic
	   fatal
	   error
	   warning
	   info
	   verbose
	   debug
	   trace

	   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 NO_COLOR, or	can be forced setting the
	   environment variable	AV_LOG_FORCE_COLOR.  The use of	the
	   environment variable	NO_COLOR is deprecated and will	be dropped in
	   a following Libav version.

       -cpuflags mask (global)
	   Set a mask that's applied to	autodetected CPU flags.	This option is
	   intended for	testing. Do not	use it unless you know what you're
	   doing.

   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:

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

       All codec AVOptions are obviously per-stream, so	the chapter on stream
       specifiers applies to them

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

       Note2 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.

   Codec AVOptions
       -b[:stream_specifier] integer (output,audio,video)
	   set bitrate (in bits/s)

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

       -flags[:stream_specifier] flags (input/output,audio,video)
	   Possible values:

	   unaligned
	       allow decoders to produce unaligned output

	   mv4 use four	motion vectors per macroblock (MPEG-4)

	   qpel
	       use 1/4-pel motion compensation

	   loop
	       use loop	filter

	   qscale
	       use fixed qscale

	   gmc use gmc

	   mv0 always try a mb with mv=<0,0>

	   input_preserved
	   pass1
	       use internal 2-pass ratecontrol in first	 pass mode

	   pass2
	       use internal 2-pass ratecontrol in second pass mode

	   gray
	       only decode/encode grayscale

	   emu_edge
	       do not draw edges

	   psnr
	       error[?]	variables will be set during encoding

	   truncated
	   naq normalize adaptive quantization

	   ildct
	       use interlaced DCT

	   low_delay
	       force low delay

	   global_header
	       place global headers in extradata instead of every keyframe

	   bitexact
	       use only	bitexact functions (except (I)DCT)

	   aic H.263 advanced intra coding / MPEG-4 AC prediction

	   ilme
	       interlaced motion estimation

	   cgop
	       closed GOP

	   output_corrupt
	       Output even potentially corrupted frames

       -me_method[:stream_specifier] integer (output,video)
	   set motion estimation method

	   Possible values:

	   zero
	       zero motion estimation (fastest)

	   full
	       full motion estimation (slowest)

	   epzs
	       EPZS motion estimation (default)

	   esa esa motion estimation (alias for	full)

	   tesa
	       tesa motion estimation

	   dia diamond motion estimation (alias	for EPZS)

	   log log motion estimation

	   phods
	       phods motion estimation

	   x1  X1 motion estimation

	   hex hex motion estimation

	   umh umh motion estimation

       -g[:stream_specifier] integer (output,video)
	   set the group of picture (GOP) size

       -ar[:stream_specifier] integer (input/output,audio)
	   set audio sampling rate (in Hz)

       -ac[:stream_specifier] integer (input/output,audio)
	   set number of audio channels

       -cutoff[:stream_specifier] integer (output,audio)
	   set cutoff bandwidth

       -frame_size[:stream_specifier] integer (output,audio)
       -qcomp[:stream_specifier] float (output,video)
	   video quantizer scale compression (VBR). Constant of	ratecontrol
	   equation. Recommended range for default rc_eq: 0.0-1.0

       -qblur[:stream_specifier] float (output,video)
	   video quantizer scale blur (VBR)

       -qmin[:stream_specifier]	integer	(output,video)
	   minimum video quantizer scale (VBR)

       -qmax[:stream_specifier]	integer	(output,video)
	   maximum video quantizer scale (VBR)

       -qdiff[:stream_specifier] integer (output,video)
	   maximum difference between the quantizer scales (VBR)

       -bf[:stream_specifier] integer (output,video)
	   use 'frames'	B-frames

       -b_qfactor[:stream_specifier] float (output,video)
	   QP factor between P-	and B-frames

       -rc_strategy[:stream_specifier] integer (output,video)
	   ratecontrol method

       -b_strategy[:stream_specifier] integer (output,video)
	   strategy to choose between I/P/B-frames

       -ps[:stream_specifier] integer (output,video)
	   RTP payload size in bytes

       -bug[:stream_specifier] flags (input,video)
	   work	around not autodetected	encoder	bugs

	   Possible values:

	   autodetect
	   old_msmpeg4
	       some old	lavc-generated MSMPEG4v3 files (no autodetection)

	   xvid_ilace
	       Xvid interlacing	bug (autodetected if FOURCC == XVIX)

	   ump4
	       (autodetected if	FOURCC == UMP4)

	   no_padding
	       padding bug (autodetected)

	   amv
	   ac_vlc
	       illegal VLC bug (autodetected per FOURCC)

	   qpel_chroma
	   std_qpel
	       old standard qpel (autodetected per FOURCC/version)

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

	   edge
	       edge padding bug	(autodetected per FOURCC/version)

	   hpel_chroma
	   dc_clip
	   ms  work around various bugs	in Microsoft's broken decoders

	   trunc
	       truncated frames

       -strict[:stream_specifier] integer (input/output,audio,video)
	   how strictly	to follow the standards

	   Possible values:

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

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

	   normal
	   unofficial
	       allow unofficial	extensions

	   experimental
	       allow non-standardized experimental things

       -b_qoffset[:stream_specifier] float (output,video)
	   QP offset between P-	and B-frames

       -err_detect[:stream_specifier] flags (input,audio,video)
	   set error detection flags

	   Possible values:

	   crccheck
	       verify embedded CRCs

	   bitstream
	       detect bitstream	specification deviations

	   buffer
	       detect improper bitstream length

	   explode
	       abort decoding on minor error detection

       -mpeg_quant[:stream_specifier] integer (output,video)
	   use MPEG quantizers instead of H.263

       -qsquish[:stream_specifier] float (output,video)
	   deprecated, use encoder private options instead

       -rc_qmod_amp[:stream_specifier] float (output,video)
	   deprecated, use encoder private options instead

       -rc_qmod_freq[:stream_specifier]	integer	(output,video)
	   deprecated, use encoder private options instead

       -rc_eq[:stream_specifier] string	(output,video)
	   deprecated, use encoder private options instead

       -maxrate[:stream_specifier] integer (output,audio,video)
	   Set maximum bitrate tolerance (in bits/s). Requires bufsize to be
	   set.

       -minrate[:stream_specifier] integer (output,audio,video)
	   Set minimum bitrate tolerance (in bits/s). Most useful in setting
	   up a	CBR encode. It is of little use	otherwise.

       -bufsize[:stream_specifier] integer (output,audio,video)
	   set ratecontrol buffer size (in bits)

       -rc_buf_aggressivity[:stream_specifier] float (output,video)
	   deprecated, use encoder private options instead

       -i_qfactor[:stream_specifier] float (output,video)
	   QP factor between P-	and I-frames

       -i_qoffset[:stream_specifier] float (output,video)
	   QP offset between P-	and I-frames

       -rc_init_cplx[:stream_specifier]	float (output,video)
	   deprecated, use encoder private options instead

       -dct[:stream_specifier] integer (output,video)
	   DCT algorithm

	   Possible values:

	   auto
	       autoselect a good one (default)

	   fastint
	       fast integer

	   int accurate	integer

	   mmx
	   altivec
	   faan
	       floating	point AAN DCT

       -lumi_mask[:stream_specifier] float (output,video)
	   compresses bright areas stronger than medium	ones

       -tcplx_mask[:stream_specifier] float (output,video)
	   temporal complexity masking

       -scplx_mask[:stream_specifier] float (output,video)
	   spatial complexity masking

       -p_mask[:stream_specifier] float	(output,video)
	   inter masking

       -dark_mask[:stream_specifier] float (output,video)
	   compresses dark areas stronger than medium ones

       -idct[:stream_specifier]	integer	(input/output,video)
	   select IDCT implementation

	   Possible values:

	   auto
	   int
	   simple
	   simplemmx
	   arm
	   altivec
	   sh4
	   simplearm
	   simplearmv5te
	   simplearmv6
	   simpleneon
	   simplealpha
	   ipp
	   xvid
	   xvidmmx
	   faani
	       floating	point AAN IDCT

       -ec[:stream_specifier] flags (input,video)
	   set error concealment strategy

	   Possible values:

	   guess_mvs
	       iterative motion	vector (MV) search (slow)

	   deblock
	       use strong deblock filter for damaged MBs

       -pred[:stream_specifier]	integer	(output,video)
	   prediction method

	   Possible values:

	   left
	   plane
	   median
       -aspect[:stream_specifier] rational number (output,video)
	   sample aspect ratio

       -debug[:stream_specifier] flags (input/output,audio,video,subtitles)
	   print specific debug	info

	   Possible values:

	   pict
	       picture info

	   rc  rate control

	   bitstream
	   mb_type
	       macroblock (MB) type

	   qp  per-block quantization parameter	(QP)

	   mv  motion vector

	   dct_coeff
	   skip
	   startcode
	   pts
	   er  error recognition

	   mmco
	       memory management control operations (H.264)

	   bugs
	   vis_qp
	       visualize quantization parameter	(QP), lower QP are tinted
	       greener

	   vis_mb_type
	       visualize block types

	   buffers
	       picture buffer allocations

	   thread_ops
	       threading operations

       -vismv[:stream_specifier] integer (input,video)
	   visualize motion vectors (MVs)

	   Possible values:

	   pf  forward predicted MVs of	P-frames

	   bf  forward predicted MVs of	B-frames

	   bb  backward	predicted MVs of B-frames

       -cmp[:stream_specifier] integer (output,video)
	   full-pel ME compare function

	   Possible values:

	   sad sum of absolute differences, fast (default)

	   sse sum of squared errors

	   satd
	       sum of absolute Hadamard	transformed differences

	   dct sum of absolute DCT transformed differences

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

	   bit number of bits needed for the block

	   rd  rate distortion optimal,	slow

	   zero
	       0

	   vsad
	       sum of absolute vertical	differences

	   vsse
	       sum of squared vertical differences

	   nsse
	       noise preserving	sum of squared differences

	   dctmax
	   chroma
       -subcmp[:stream_specifier] integer (output,video)
	   sub-pel ME compare function

	   Possible values:

	   sad sum of absolute differences, fast (default)

	   sse sum of squared errors

	   satd
	       sum of absolute Hadamard	transformed differences

	   dct sum of absolute DCT transformed differences

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

	   bit number of bits needed for the block

	   rd  rate distortion optimal,	slow

	   zero
	       0

	   vsad
	       sum of absolute vertical	differences

	   vsse
	       sum of squared vertical differences

	   nsse
	       noise preserving	sum of squared differences

	   dctmax
	   chroma
       -mbcmp[:stream_specifier] integer (output,video)
	   macroblock compare function

	   Possible values:

	   sad sum of absolute differences, fast (default)

	   sse sum of squared errors

	   satd
	       sum of absolute Hadamard	transformed differences

	   dct sum of absolute DCT transformed differences

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

	   bit number of bits needed for the block

	   rd  rate distortion optimal,	slow

	   zero
	       0

	   vsad
	       sum of absolute vertical	differences

	   vsse
	       sum of squared vertical differences

	   nsse
	       noise preserving	sum of squared differences

	   dctmax
	   chroma
       -ildctcmp[:stream_specifier] integer (output,video)
	   interlaced DCT compare function

	   Possible values:

	   sad sum of absolute differences, fast (default)

	   sse sum of squared errors

	   satd
	       sum of absolute Hadamard	transformed differences

	   dct sum of absolute DCT transformed differences

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

	   bit number of bits needed for the block

	   rd  rate distortion optimal,	slow

	   zero
	       0

	   vsad
	       sum of absolute vertical	differences

	   vsse
	       sum of squared vertical differences

	   nsse
	       noise preserving	sum of squared differences

	   dctmax
	   chroma
       -dia_size[:stream_specifier] integer (output,video)
	   diamond type	& size for motion estimation

       -last_pred[:stream_specifier] integer (output,video)
	   amount of motion predictors from the	previous frame

       -preme[:stream_specifier] integer (output,video)
	   pre motion estimation

       -precmp[:stream_specifier] integer (output,video)
	   pre motion estimation compare function

	   Possible values:

	   sad sum of absolute differences, fast (default)

	   sse sum of squared errors

	   satd
	       sum of absolute Hadamard	transformed differences

	   dct sum of absolute DCT transformed differences

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

	   bit number of bits needed for the block

	   rd  rate distortion optimal,	slow

	   zero
	       0

	   vsad
	       sum of absolute vertical	differences

	   vsse
	       sum of squared vertical differences

	   nsse
	       noise preserving	sum of squared differences

	   dctmax
	   chroma
       -pre_dia_size[:stream_specifier]	integer	(output,video)
	   diamond type	& size for motion estimation pre-pass

       -subq[:stream_specifier]	integer	(output,video)
	   sub-pel motion estimation quality

       -me_range[:stream_specifier] integer (output,video)
	   limit motion	vectors	range (1023 for	DivX player)

       -ibias[:stream_specifier] integer (output,video)
	   intra quant bias

       -pbias[:stream_specifier] integer (output,video)
	   inter quant bias

       -global_quality[:stream_specifier] integer (output,audio,video)
       -coder[:stream_specifier] integer (output,video)
	   Possible values:

	   vlc variable	length coder / Huffman coder

	   ac  arithmetic coder

	   raw raw (no encoding)

	   rle run-length coder

	   deflate
	       deflate-based coder

       -context[:stream_specifier] integer (output,video)
	   context model

       -mbd[:stream_specifier] integer (output,video)
	   macroblock decision algorithm (high quality mode)

	   Possible values:

	   simple
	       use mbcmp (default)

	   bits
	       use fewest bits

	   rd  use best	rate distortion

       -sc_threshold[:stream_specifier]	integer	(output,video)
	   scene change	threshold

       -lmin[:stream_specifier]	integer	(output,video)
	   deprecated, use encoder private options instead

       -lmax[:stream_specifier]	integer	(output,video)
	   deprecated, use encoder private options instead

       -nr[:stream_specifier] integer (output,video)
	   noise reduction

       -rc_init_occupancy[:stream_specifier] integer (output,video)
	   number of bits which	should be loaded into the rc buffer before
	   decoding starts

       -flags2[:stream_specifier] flags	(input/output,audio,video)
	   Possible values:

	   fast
	       allow non-spec-compliant	speedup	tricks

	   noout
	       skip bitstream encoding

	   ignorecrop
	       ignore cropping information from	sps

	   local_header
	       place global headers at every keyframe instead of in extradata

       -error[:stream_specifier] integer (output,video)
       -threads[:stream_specifier] integer (input/output,video)
	   Possible values:

	   auto
	       autodetect a suitable number of threads to use

       -me_threshold[:stream_specifier]	integer	(output,video)
	   motion estimation threshold

       -mb_threshold[:stream_specifier]	integer	(output,video)
	   macroblock threshold

       -dc[:stream_specifier] integer (output,video)
	   intra_dc_precision

       -nssew[:stream_specifier] integer (output,video)
	   nsse	weight

       -skip_top[:stream_specifier] integer (input,video)
	   number of macroblock	rows at	the top	which are skipped

       -skip_bottom[:stream_specifier] integer (input,video)
	   number of macroblock	rows at	the bottom which are skipped

       -profile[:stream_specifier] integer (output,audio,video)
	   Possible values:

	   unknown
	   aac_main
	   aac_low
	   aac_ssr
	   aac_ltp
	   aac_he
	   aac_he_v2
	   aac_ld
	   aac_eld
	   mpeg2_aac_low
	   mpeg2_aac_he
	   dts
	   dts_es
	   dts_96_24
	   dts_hd_hra
	   dts_hd_ma
       -level[:stream_specifier] integer (output,audio,video)
	   Possible values:

	   unknown
       -skip_threshold[:stream_specifier] integer (output,video)
	   frame skip threshold

       -skip_factor[:stream_specifier] integer (output,video)
	   frame skip factor

       -skip_exp[:stream_specifier] integer (output,video)
	   frame skip exponent

       -skipcmp[:stream_specifier] integer (output,video)
	   frame skip compare function

	   Possible values:

	   sad sum of absolute differences, fast (default)

	   sse sum of squared errors

	   satd
	       sum of absolute Hadamard	transformed differences

	   dct sum of absolute DCT transformed differences

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

	   bit number of bits needed for the block

	   rd  rate distortion optimal,	slow

	   zero
	       0

	   vsad
	       sum of absolute vertical	differences

	   vsse
	       sum of squared vertical differences

	   nsse
	       noise preserving	sum of squared differences

	   dctmax
	   chroma
       -border_mask[:stream_specifier] float (output,video)
	   deprecated, use encoder private options instead

       -mblmin[:stream_specifier] integer (output,video)
	   minimum macroblock Lagrange factor (VBR)

       -mblmax[:stream_specifier] integer (output,video)
	   maximum macroblock Lagrange factor (VBR)

       -mepc[:stream_specifier]	integer	(output,video)
	   motion estimation bitrate penalty compensation (1.0 = 256)

       -skip_loop_filter[:stream_specifier] integer (input,video)
	   Possible values:

	   none
	   default
	   noref
	   bidir
	   nokey
	   all
       -skip_idct[:stream_specifier] integer (input,video)
	   Possible values:

	   none
	   default
	   noref
	   bidir
	   nokey
	   all
       -skip_frame[:stream_specifier] integer (input,video)
	   Possible values:

	   none
	   default
	   noref
	   bidir
	   nokey
	   all
       -bidir_refine[:stream_specifier]	integer	(output,video)
	   refine the two motion vectors used in bidirectional macroblocks

       -brd_scale[:stream_specifier] integer (output,video)
	   downscale frames for	dynamic	B-frame	decision

       -keyint_min[:stream_specifier] integer (output,video)
	   minimum interval between IDR-frames (x264)

       -refs[:stream_specifier]	integer	(output,video)
	   reference frames to consider	for motion compensation

       -chromaoffset[:stream_specifier]	integer	(output,video)
	   chroma QP offset from luma

       -trellis[:stream_specifier] integer (output,audio,video)
	   rate-distortion optimal quantization

       -sc_factor[:stream_specifier] integer (output,video)
	   multiplied by qscale	for each frame and added to scene_change_score

       -mv0_threshold[:stream_specifier] integer (output,video)
       -b_sensitivity[:stream_specifier] integer (output,video)
	   adjust sensitivity of b_frame_strategy 1

       -compression_level[:stream_specifier] integer (output,audio,video)
       -min_prediction_order[:stream_specifier]	integer	(output,audio)
       -max_prediction_order[:stream_specifier]	integer	(output,audio)
       -timecode_frame_start[:stream_specifier]	integer	(output,video)
	   GOP timecode	frame start number, in non-drop-frame format

       -channel_layout[:stream_specifier] integer (input/output,audio)
	   Possible values:

       -request_channel_layout[:stream_specifier] integer (input,audio)
	   Possible values:

       -rc_max_vbv_use[:stream_specifier] float	(output,video)
       -rc_min_vbv_use[:stream_specifier] float	(output,video)
       -ticks_per_frame[:stream_specifier] integer (input/output,audio,video)
       -color_primaries[:stream_specifier] integer (input/output,video)
	   color primaries

	   Possible values:

	   bt709
	       BT.709

	   unknown
	       Unspecified

	   bt470m
	       BT.470 M

	   bt470bg
	       BT.470 BG

	   smpte170m
	       SMPTE 170 M

	   smpte240m
	       SMPTE 240 M

	   film
	       Film

	   bt2020
	       BT.2020

	   smpte428
	       SMPTE 428-1

	   smpte431
	       SMPTE 431-2

	   smpte432
	       SMPTE 422-1

	   unspecified
	       Unspecified

	   smptest428_1
	       SMPTE 428-1

       -color_trc[:stream_specifier] integer (input/output,video)
	   color transfer characteristics

	   Possible values:

	   bt709
	       BT.709

	   unknown
	       Unspecified

	   gamma22
	       BT.470 M

	   gamma28
	       BT.470 BG

	   smpte170m
	       SMPTE 170 M

	   smpte240m
	       SMPTE 240 M

	   linear
	       Linear

	   log100
	       Log

	   log316
	       Log square root

	   iec61966-2-4
	       IEC 61966-2-4

	   bt1361e
	       BT.1361

	   iec61966-2-1
	       IEC 61966-2-1

	   bt2020-10
	       BT.2020 - 10 bit

	   bt2020-12
	       BT.2020 - 12 bit

	   smpte2084
	       SMPTE 2084

	   smpte428
	       SMPTE 428-1

	   arib-std-b67
	       ARIB STD-B67

	   unspecified
	       Unspecified

	   log Log

	   log_sqrt
	       Log square root

	   iec61966_2_4
	       IEC 61966-2-4

	   bt1361
	       BT.1361

	   iec61966_2_1
	       IEC 61966-2-1

	   bt2020_10bit
	       BT.2020 - 10 bit

	   bt2020_12bit
	       BT.2020 - 12 bit

	   smptest2084
	       SMPTE 2084

	   smptest428_1
	       SMPTE 428-1

       -colorspace[:stream_specifier] integer (input/output,video)
	   color space

	   Possible values:

	   rgb RGB

	   bt709
	       BT.709

	   unknown
	       Unspecified

	   fcc FCC

	   bt470bg
	       BT.470 BG

	   smpte170m
	       SMPTE 170 M

	   smpte240m
	       SMPTE 240 M

	   ycocg
	       YCOCG

	   bt2020nc
	       BT.2020 NCL

	   bt2020c
	       BT.2020 CL

	   smpte2085
	       SMPTE 2085

	   unspecified
	       Unspecified

	   bt2020_ncl
	       BT.2020 NCL

	   bt2020_cl
	       BT.2020 CL

       -color_range[:stream_specifier] integer (input/output,video)
	   color range

	   Possible values:

	   unknown
	       Unspecified

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

	   pc  JPEG (2^n-1)

	   unspecified
	       Unspecified

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

	   jpeg
	       JPEG (2^n-1)

       -chroma_sample_location[:stream_specifier] integer (input/output,video)
	   chroma sample location

	   Possible values:

	   unknown
	       Unspecified

	   left
	       Left

	   center
	       Center

	   topleft
	       Top-left

	   top Top

	   bottomleft
	       Bottom-left

	   bottom
	       Bottom

	   unspecified
	       Unspecified

       -slices[:stream_specifier] integer (output,video)
	   number of slices, used in parallelized encoding

       -thread_type[:stream_specifier] flags (input/output,video)
	   select multithreading type

	   Possible values:

	   slice
	   frame
       -audio_service_type[:stream_specifier] integer (output,audio)
	   audio service type

	   Possible values:

	   ma  Main Audio Service

	   ef  Effects

	   vi  Visually	Impaired

	   hi  Hearing Impaired

	   di  Dialogue

	   co  Commentary

	   em  Emergency

	   vo  Voice Over

	   ka  Karaoke

       -request_sample_fmt[:stream_specifier] integer (input,audio)
	   Possible values:

	   u8  8-bit unsigned integer

	   s16 16-bit signed integer

	   s32 32-bit signed integer

	   flt 32-bit float

	   dbl 64-bit double

	   u8p 8-bit unsigned integer planar

	   s16p
	       16-bit signed integer planar

	   s32p
	       32-bit signed integer planar

	   fltp
	       32-bit float planar

	   dblp
	       64-bit double planar

       -refcounted_frames[:stream_specifier] integer (input,audio,video)
       -side_data_only_packets[:stream_specifier] integer (output,audio,video)

   Format AVOptions
       -probesize integer (input)
	   set probing size

       -packetsize integer (output)
	   set packet size

       -fflags flags (input/output)
	   Possible values:

	   flush_packets
	       reduce the latency by flushing out packets immediately

	   ignidx
	       ignore index

	   genpts
	       generate	pts

	   nofillin
	       do not fill in missing values that can be exactly calculated

	   noparse
	       disable AVParsers, this needs nofillin too

	   igndts
	       ignore dts

	   discardcorrupt
	       discard corrupted frames

	   nobuffer
	       reduce the latency introduced by	optional buffering

	   bitexact
	       do not write random/volatile data

       -analyzeduration	integer	(input)
	   how many microseconds are analyzed to estimate duration

       -cryptokey hexadecimal string (input)
	   decryption key

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

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

       -fdebug flags (input/output)
	   print specific debug	info

	   Possible values:

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

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

       -f_err_detect flags (input)
	   set error detection flags (deprecated; use err_detect, save via
	   avconv)

	   Possible values:

	   crccheck
	       verify embedded CRCs

	   bitstream
	       detect bitstream	specification deviations

	   buffer
	       detect improper bitstream length

	   explode
	       abort decoding on minor error detection

       -err_detect flags (input)
	   set error detection flags

	   Possible values:

	   crccheck
	       verify embedded CRCs

	   bitstream
	       detect bitstream	specification deviations

	   buffer
	       detect improper bitstream length

	   explode
	       abort decoding on minor error detection

       -max_interleave_delta integer (output)
	   maximum buffering duration for interleaving

       -f_strict integer (input/output)
	   how strictly	to follow the standards	(deprecated; use strict, save
	   via avconv)

	   Possible values:

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

	   normal
	   experimental
	       allow non-standardized experimental variants

       -strict integer (input/output)
	   how strictly	to follow the standards

	   Possible values:

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

	   normal
	   experimental
	       allow non-standardized experimental variants

       -max_ts_probe integer (input)
	   maximum number of packets to	read while waiting for the first
	   timestamp

       -avoid_negative_ts integer (output)
	   shift timestamps so they start at 0

	   Possible values:

	   auto
	       enabled when required by	target format

	   make_non_negative
	       shift timestamps	so they	are non	negative

	   make_zero
	       shift timestamps	so they	start at 0

       -protocol_blacklist string (input/output)
	   A comma-separated list of blacklisted protocols used	for opening
	   files internally by lavf

       -protocol_whitelist string (input/output)
	   A comma-separated list of whitelisted protocols used	for opening
	   files internally by lavf

   Main	options
       -f format
	   Force format	to use.

       -of formatter
	   Use a specific formatter to output the document. The	following
	   formatters are available

	   ini
	   json
	   old Pseudo-INI format that used to be the only one available	in old
	       avprobe versions.

       -unit
	   Show	the unit of the	displayed values.

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

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

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

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

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

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

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

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

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

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

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

DEMUXERS
       Demuxers	are configured elements	in Libav which allow to	read the
       multimedia streams from a particular type of file.

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

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

       The option "-formats" of	the av*	tools will display the list of enabled
       demuxers.

       The description of some of the currently	available demuxers follows.

   image2
       Image file demuxer.

       This demuxer reads from a list of image files specified by a pattern.

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

       If the pattern contains "%d" or "%0Nd", the first filename of the file
       list specified by the pattern must contain a number inclusively
       contained between 0 and 4, all the following numbers must be
       sequential. This	limitation may be hopefully fixed.

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

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

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

       The following example shows how to use avconv for creating a video from
       the images in the file sequence img-001.jpeg, img-002.jpeg, ...,
       assuming	an input framerate of 10 frames	per second:

	       avconv -i 'img-%03d.jpeg' -r 10 out.mkv

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

	       avconv -i img.jpeg img.png

       -pixel_format format
	   Set the pixel format	(for raw image)

       -video_size   size
	   Set the frame size (for raw image)

       -framerate    rate
	   Set the frame rate

       -loop	     bool
	   Loop	over the images

       -start_number start
	   Specify the first number in the sequence

   applehttp
       Apple HTTP Live Streaming demuxer.

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

   flv
       Adobe Flash Video Format	demuxer.

       This demuxer is used to demux FLV files and RTMP	network	streams.

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

   asf
       Advanced	Systems	Format demuxer.

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

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

MUXERS
       Muxers are configured elements in Libav which allow writing multimedia
       streams to a particular type of file.

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

       You can disable all the muxers with the configure option
       "--disable-muxers" and selectively enable / disable single muxers with
       the options "--enable-muxer=MUXER" / "--disable-muxer=MUXER".

       The option "-formats" of	the av*	tools will display the list of enabled
       muxers.

       A description of	some of	the currently available	muxers follows.

   crc
       CRC (Cyclic Redundancy Check) testing format.

       This muxer computes and prints the Adler-32 CRC of all the input	audio
       and video frames. By default audio frames are converted to signed
       16-bit raw audio	and video frames to raw	video before computing the
       CRC.

       The output of the muxer consists	of a single line of the	form:
       CRC=0xCRC, where	CRC is a hexadecimal number 0-padded to	8 digits
       containing the CRC for all the decoded input frames.

       For example to compute the CRC of the input, and	store it in the	file
       out.crc:

	       avconv -i INPUT -f crc out.crc

       You can print the CRC to	stdout with the	command:

	       avconv -i INPUT -f crc -

       You can select the output format	of each	frame with avconv by
       specifying the audio and	video codec and	format.	For example to compute
       the CRC of the input audio converted to PCM unsigned 8-bit and the
       input video converted to	MPEG-2 video, use the command:

	       avconv -i INPUT -c:a pcm_u8 -c:v	mpeg2video -f crc -

       See also	the framecrc muxer.

   framecrc
       Per-frame CRC (Cyclic Redundancy	Check) testing format.

       This muxer computes and prints the Adler-32 CRC for each	decoded	audio
       and video frame.	By default audio frames	are converted to signed	16-bit
       raw audio and video frames to raw video before computing	the CRC.

       The output of the muxer consists	of a line for each audio and video
       frame of	the form: stream_index,	frame_dts, frame_size, 0xCRC, where
       CRC is a	hexadecimal number 0-padded to 8 digits	containing the CRC of
       the decoded frame.

       For example to compute the CRC of each decoded frame in the input, and
       store it	in the file out.crc:

	       avconv -i INPUT -f framecrc out.crc

       You can print the CRC of	each decoded frame to stdout with the command:

	       avconv -i INPUT -f framecrc -

       You can select the output format	of each	frame with avconv by
       specifying the audio and	video codec and	format.	For example, to
       compute the CRC of each decoded input audio frame converted to PCM
       unsigned	8-bit and of each decoded input	video frame converted to
       MPEG-2 video, use the command:

	       avconv -i INPUT -c:a pcm_u8 -c:v	mpeg2video -f framecrc -

       See also	the crc	muxer.

   hls
       Apple HTTP Live Streaming muxer that segments MPEG-TS according to the
       HTTP Live Streaming specification.

       It creates a playlist file and numbered segment files. The output
       filename	specifies the playlist filename; the segment filenames receive
       the same	basename as the	playlist, a sequential number and a .ts
       extension.

	       avconv -i in.nut	out.m3u8

       -hls_time seconds
	   Set the segment length in seconds.

       -hls_list_size size
	   Set the maximum number of playlist entries.

       -hls_wrap wrap
	   Set the number after	which index wraps.

       -start_number number
	   Start the sequence from number.

       -hls_base_url baseurl
	   Append baseurl to every entry in the	playlist.  Useful to generate
	   playlists with absolute paths.

       -hls_allow_cache	allowcache
	   Explicitly set whether the client MAY (1) or	MUST NOT (0) cache
	   media segments

       -hls_version version
	   Set the protocol version. Enables or	disables version-specific
	   features such as the	integer	(version 2) or decimal EXTINF values
	   (version 3).

   image2
       Image file muxer.

       The image file muxer writes video frames	to image files.

       The output filenames are	specified by a pattern,	which can be used to
       produce sequentially numbered series of files.  The pattern may contain
       the string "%d" or "%0Nd", this string specifies	the position of	the
       characters representing a numbering in the filenames. If	the form
       "%0Nd" is used, the string representing the number in each filename is
       0-padded	to N digits. The literal character '%' can be specified	in the
       pattern with the	string "%%".

       If the pattern contains "%d" or "%0Nd", the first filename of the file
       list specified will contain the number 1, all the following numbers
       will be sequential.

       The pattern may contain a suffix	which is used to automatically
       determine the format of the image files to write.

       For example the pattern "img-%03d.bmp" will specify a sequence of
       filenames of the	form img-001.bmp, img-002.bmp, ..., img-010.bmp, etc.
       The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
       form img%-1.jpg,	img%-2.jpg, ..., img%-10.jpg, etc.

       The following example shows how to use avconv for creating a sequence
       of files	img-001.jpeg, img-002.jpeg, ..., taking	one image every	second
       from the	input video:

	       avconv -i in.avi	-vsync 1 -r 1 -f image2	'img-%03d.jpeg'

       Note that with avconv, if the format is not specified with the "-f"
       option and the output filename specifies	an image file format, the
       image2 muxer is automatically selected, so the previous command can be
       written as:

	       avconv -i in.avi	-vsync 1 -r 1 'img-%03d.jpeg'

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

	       avconv -i in.avi	-f image2 -frames:v 1 img.jpeg

       -start_number number
	   Start the sequence from number.

       -update number
	   If number is	nonzero, the filename will always be interpreted as
	   just	a filename, not	a pattern, and this file will be continuously
	   overwritten with new	images.

   matroska
       Matroska	container muxer.

       This muxer implements the matroska and webm container specs.

       The recognized metadata settings	in this	muxer are:

       title=title name
	   Name	provided to a single track

       language=language name
	   Specifies the language of the track in the Matroska languages form

       STEREO_MODE=mode
	   Stereo 3D video layout of two views in a single video track

	   mono
	       video is	not stereo

	   left_right
	       Both views are arranged side by side, Left-eye view is on the
	       left

	   bottom_top
	       Both views are arranged in top-bottom orientation, Left-eye
	       view is at bottom

	   top_bottom
	       Both views are arranged in top-bottom orientation, Left-eye
	       view is on top

	   checkerboard_rl
	       Each view is arranged in	a checkerboard interleaved pattern,
	       Left-eye	view being first

	   checkerboard_lr
	       Each view is arranged in	a checkerboard interleaved pattern,
	       Right-eye view being first

	   row_interleaved_rl
	       Each view is constituted	by a row based interleaving, Right-eye
	       view is first row

	   row_interleaved_lr
	       Each view is constituted	by a row based interleaving, Left-eye
	       view is first row

	   col_interleaved_rl
	       Both views are arranged in a column based interleaving manner,
	       Right-eye view is first column

	   col_interleaved_lr
	       Both views are arranged in a column based interleaving manner,
	       Left-eye	view is	first column

	   anaglyph_cyan_red
	       All frames are in anaglyph format viewable through red-cyan
	       filters

	   right_left
	       Both views are arranged side by side, Right-eye view is on the
	       left

	   anaglyph_green_magenta
	       All frames are in anaglyph format viewable through green-
	       magenta filters

	   block_lr
	       Both eyes laced in one Block, Left-eye view is first

	   block_rl
	       Both eyes laced in one Block, Right-eye view is first

       For example a 3D	WebM clip can be created using the following command
       line:

	       avconv -i sample_left_right_clip.mpg -an	-c:v libvpx -metadata STEREO_MODE=left_right -y	stereo_clip.webm

       This muxer supports the following options:

       reserve_index_space
	   By default, this muxer writes the index for seeking (called cues in
	   Matroska terms) at the end of the file, because it cannot know in
	   advance how much space to leave for the index at the	beginning of
	   the file. However for some use cases	-- e.g.	 streaming where
	   seeking is possible but slow	-- it is useful	to put the index at
	   the beginning of the	file.

	   If this option is set to a non-zero value, the muxer	will reserve a
	   given amount	of space in the	file header and	then try to write the
	   cues	there when the muxing finishes.	If the available space does
	   not suffice,	muxing will fail. A safe size for most use cases
	   should be about 50kB	per hour of video.

	   Note	that cues are only written if the output is seekable and this
	   option will have no effect if it is not.

   mov,	mp4, ismv
       The mov/mp4/ismv	muxer supports fragmentation. Normally,	a MOV/MP4 file
       has all the metadata about all packets stored in	one location (written
       at the end of the file, it can be moved to the start for	better
       playback	using the qt-faststart tool). A	fragmented file	consists of a
       number of fragments, where packets and metadata about these packets are
       stored together.	Writing	a fragmented file has the advantage that the
       file is decodable even if the writing is	interrupted (while a normal
       MOV/MP4 is undecodable if it is not properly finished), and it requires
       less memory when	writing	very long files	(since writing normal MOV/MP4
       files stores info about every single packet in memory until the file is
       closed).	The downside is	that it	is less	compatible with	other
       applications.

       Fragmentation is	enabled	by setting one of the AVOptions	that define
       how to cut the file into	fragments:

       -movflags frag_keyframe
	   Start a new fragment	at each	video keyframe.

       -frag_duration duration
	   Create fragments that are duration microseconds long.

       -frag_size size
	   Create fragments that contain up to size bytes of payload data.

       -movflags frag_custom
	   Allow the caller to manually	choose when to cut fragments, by
	   calling "av_write_frame(ctx,	NULL)" to write	a fragment with	the
	   packets written so far. (This is only useful	with other
	   applications	integrating libavformat, not from avconv.)

       -min_frag_duration duration
	   Don't create	fragments that are shorter than	duration microseconds
	   long.

       If more than one	condition is specified,	fragments are cut when one of
       the specified conditions	is fulfilled. The exception to this is
       "-min_frag_duration", which has to be fulfilled for any of the other
       conditions to apply.

       Additionally, the way the output	file is	written	can be adjusted
       through a few other options:

       -movflags empty_moov
	   Write an initial moov atom directly at the start of the file,
	   without describing any samples in it. Generally, an mdat/moov pair
	   is written at the start of the file,	as a normal MOV/MP4 file,
	   containing only a short portion of the file.	With this option set,
	   there is no initial mdat atom, and the moov atom only describes the
	   tracks but has a zero duration.

	   This	option is implicitly set when writing ismv (Smooth Streaming)
	   files.

       -movflags separate_moof
	   Write a separate moof (movie	fragment) atom for each	track.
	   Normally, packets for all tracks are	written	in a moof atom (which
	   is slightly more efficient),	but with this option set, the muxer
	   writes one moof/mdat	pair for each track, making it easier to
	   separate tracks.

	   This	option is implicitly set when writing ismv (Smooth Streaming)
	   files.

       -movflags faststart
	   Run a second	pass moving the	index (moov atom) to the beginning of
	   the file.  This operation can take a	while, and will	not work in
	   various situations such as fragmented output, thus it is not
	   enabled by default.

       -movflags disable_chpl
	   Disable Nero	chapter	markers	(chpl atom).  Normally,	both Nero
	   chapters and	a QuickTime chapter track are written to the file.
	   With	this option set, only the QuickTime chapter track will be
	   written. Nero chapters can cause failures when the file is
	   reprocessed with certain tagging programs.

       -movflags omit_tfhd_offset
	   Do not write	any absolute base_data_offset in tfhd atoms. This
	   avoids tying	fragments to absolute byte positions in	the
	   file/streams.

       -movflags default_base_moof
	   Similarly to	the omit_tfhd_offset, this flag	avoids writing the
	   absolute base_data_offset field in tfhd atoms, but does so by using
	   the new default-base-is-moof	flag instead. This flag	is new from
	   14496-12:2012. This may make	the fragments easier to	parse in
	   certain circumstances (avoiding basing track	fragment location
	   calculations	on the implicit	end of the previous track fragment).

       Smooth Streaming	content	can be pushed in real time to a	publishing
       point on	IIS with this muxer. Example:

	       avconv -re <<normal input/transcoding options>> -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)

   mp3
       The MP3 muxer writes a raw MP3 stream with the following	optional
       features:

       o   An ID3v2 metadata header at the beginning (enabled by default).
	   Versions 2.3	and 2.4	are supported, the "id3v2_version" private
	   option controls which one is	used (3	or 4). Setting "id3v2_version"
	   to 0	disables the ID3v2 header completely.

	   The muxer supports writing attached pictures	(APIC frames) to the
	   ID3v2 header.  The pictures are supplied to the muxer in form of a
	   video stream	with a single packet. There can	be any number of those
	   streams, each will correspond to a single APIC frame.  The stream
	   metadata tags title and comment map to APIC description and picture
	   type	respectively. See <http://id3.org/id3v2.4.0-frames> for
	   allowed picture types.

	   Note	that the APIC frames must be written at	the beginning, so the
	   muxer will buffer the audio frames until it gets all	the pictures.
	   It is therefore advised to provide the pictures as soon as possible
	   to avoid excessive buffering.

       o   A Xing/LAME frame right after the ID3v2 header (if present).	It is
	   enabled by default, but will	be written only	if the output is
	   seekable. The "write_xing" private option can be used to disable
	   it.	The frame contains various information that may	be useful to
	   the decoder,	like the audio duration	or encoder delay.

       o   A legacy ID3v1 tag at the end of the	file (disabled by default). It
	   may be enabled with the "write_id3v1" private option, but as	its
	   capabilities	are very limited, its usage is not recommended.

       Examples:

       Write an	mp3 with an ID3v2.3 header and an ID3v1	footer:

	       avconv -i INPUT -id3v2_version 3	-write_id3v1 1 out.mp3

       Attach a	picture	to an mp3:

	       avconv -i input.mp3 -i cover.png	-c copy	-metadata:s:v title="Album cover"
	       -metadata:s:v comment="Cover (Front)" out.mp3

       Write a "clean" MP3 without any extra features:

	       avconv -i input.wav -write_xing 0 -id3v2_version	0 out.mp3

   mpegts
       MPEG transport stream muxer.

       This muxer implements ISO 13818-1 and part of ETSI EN 300 468.

       The muxer options are:

       -mpegts_original_network_id number
	   Set the original_network_id (default	0x0001). This is unique
	   identifier of a network in DVB. Its main use	is in the unique
	   identification of a service through the path	Original_Network_ID,
	   Transport_Stream_ID.

       -mpegts_transport_stream_id number
	   Set the transport_stream_id (default	0x0001). This identifies a
	   transponder in DVB.

       -mpegts_service_id number
	   Set the service_id (default 0x0001) also known as program in	DVB.

       -mpegts_pmt_start_pid number
	   Set the first PID for PMT (default 0x1000, max 0x1f00).

       -mpegts_start_pid number
	   Set the first PID for data packets (default 0x0100, max 0x0f00).

       -muxrate	number
	   Set a constant muxrate (default VBR).

       -pcr_period numer
	   Override the	default	PCR retransmission time	(default 20ms),
	   ignored if variable muxrate is selected.

       The recognized metadata settings	in mpegts muxer	are "service_provider"
       and "service_name". If they are not set the default for
       "service_provider" is "Libav" and the default for "service_name"	is
       "Service01".

	       avconv -i file.mpg -c copy \
		    -mpegts_original_network_id	0x1122 \
		    -mpegts_transport_stream_id	0x3344 \
		    -mpegts_service_id 0x5566 \
		    -mpegts_pmt_start_pid 0x1500 \
		    -mpegts_start_pid 0x150 \
		    -metadata service_provider="Some provider" \
		    -metadata service_name="Some Channel" \
		    -y out.ts

   null
       Null muxer.

       This muxer does not generate any	output file, it	is mainly useful for
       testing or benchmarking purposes.

       For example to benchmark	decoding with avconv you can use the command:

	       avconv -benchmark -i INPUT -f null out.null

       Note that the above command does	not read or write the out.null file,
       but specifying the output file is required by the avconv	syntax.

       Alternatively you can write the command as:

	       avconv -benchmark -i INPUT -f null -

   nut
       -syncpoints flags
	   Change the syncpoint	usage in nut:

	   default use the normal low-overhead seeking aids.
	   none	do not use the syncpoints at all, reducing the overhead	but
	   making the stream non-seekable;
	   timestamped extend the syncpoint with a wallclock field.

	   The none and	timestamped flags are experimental.

	       avconv -i INPUT -f_strict experimental -syncpoints none - | processor

   ogg
       Ogg container muxer.

       -page_duration duration
	   Preferred page duration, in microseconds. The muxer will attempt to
	   create pages	that are approximately duration	microseconds long.
	   This	allows the user	to compromise between seek granularity and
	   container overhead. The default is 1	second.	A value	of 0 will fill
	   all segments, making	pages as large as possible. A value of 1 will
	   effectively use 1 packet-per-page in	most situations, giving	a
	   small seek granularity at the cost of additional container
	   overhead.

       -serial_offset value
	   Serial value	from which to set the streams serial number.  Setting
	   it to different and sufficiently large values ensures that the
	   produced ogg	files can be safely chained.

   segment
       Basic stream segmenter.

       The segmenter muxer outputs streams to a	number of separate files of
       nearly fixed duration. Output filename pattern can be set in a fashion
       similar to image2.

       Every segment starts with a video keyframe, if a	video stream is
       present.	 The segment muxer works best with a single constant frame
       rate video.

       Optionally it can generate a flat list of the created segments, one
       segment per line.

       segment_format format
	   Override the	inner container	format,	by default it is guessed by
	   the filename	extension.

       segment_time t
	   Set segment duration	to t seconds.

       segment_list name
	   Generate also a listfile named name.

       segment_list_type type
	   Select the listing format.

	   flat	use a simple flat list of entries.
	   hls use a m3u8-like structure.
       segment_list_size size
	   Overwrite the listfile once it reaches size entries.

       segment_list_entry_prefix prefix
	   Prepend prefix to each entry. Useful	to generate absolute paths.

       segment_wrap limit
	   Wrap	around segment index once it reaches limit.

	       avconv -i in.mkv	-c copy	-map 0 -f segment -list	out.list out%03d.nut

PROTOCOLS
       Protocols are configured	elements in Libav which	allow to access
       resources which require the use of a particular protocol.

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

       You can disable all the protocols using the configure option
       "--disable-protocols", and selectively enable a protocol	using the
       option "--enable-protocol=PROTOCOL", or you can disable a particular
       protocol	using the option "--disable-protocol=PROTOCOL".

       The option "-protocols" of the av* tools	will display the list of
       supported protocols.

       All protocols accept the	following options:

       rw_timeout
	   Maximum time	to wait	for (network) read/write operations to
	   complete, in	microseconds.

       A description of	the currently available	protocols follows.

   concat
       Physical	concatenation protocol.

       Allow to	read and seek from many	resource in sequence as	if they	were a
       unique resource.

       A URL accepted by this protocol has the syntax:

	       concat:<URL1>|<URL2>|...|<URLN>

       where URL1, URL2, ..., URLN are the urls	of the resource	to be
       concatenated, each one possibly specifying a distinct protocol.

       For example to read a sequence of files split1.mpeg, split2.mpeg,
       split3.mpeg with	avplay use the command:

	       avplay concat:split1.mpeg\|split2.mpeg\|split3.mpeg

       Note that you may need to escape	the character "|" which	is special for
       many shells.

   file
       File access protocol.

       Allow to	read from or read to a file.

       For example to read from	a file input.mpeg with avconv use the command:

	       avconv -i file:input.mpeg output.mpeg

       The av* tools default to	the file protocol, that	is a resource
       specified with the name "FILE.mpeg" is interpreted as the URL
       "file:FILE.mpeg".

       This protocol accepts the following options:

       follow
	   If set to 1,	the protocol will retry	reading	at the end of the
	   file, allowing reading files	that still are being written. In order
	   for this to terminate, you either need to use the rw_timeout
	   option, or use the interrupt	callback (for API users).

   gopher
       Gopher protocol.

   hls
       Read Apple HTTP Live Streaming compliant	segmented stream as a uniform
       one. The	M3U8 playlists describing the segments can be remote HTTP
       resources or local files, accessed using	the standard file protocol.
       The nested protocol is declared by specifying "+proto" after the	hls
       URI scheme name,	where proto is either "file" or	"http".

	       hls+http://host/path/to/remote/resource.m3u8
	       hls+file://path/to/local/resource.m3u8

       Using this protocol is discouraged - the	hls demuxer should work	just
       as well (if not,	please report the issues) and is more complete.	 To
       use the hls demuxer instead, simply use the direct URLs to the m3u8
       files.

   http
       HTTP (Hyper Text	Transfer Protocol).

       This protocol accepts the following options:

       chunked_post
	   If set to 1 use chunked Transfer-Encoding for posts,	default	is 1.

       content_type
	   Set a specific content type for the POST messages.

       headers
	   Set custom HTTP headers, can	override built in default headers. The
	   value must be a string encoding the headers.

       multiple_requests
	   Use persistent connections if set to	1, default is 0.

       post_data
	   Set custom HTTP post	data.

       user_agent
	   Override the	User-Agent header. If not specified a string of	the
	   form	"Lavf/<version>" will be used.

       mime_type
	   Export the MIME type.

       icy If set to 1 request ICY (SHOUTcast) metadata	from the server. If
	   the server supports this, the metadata has to be retrieved by the
	   application by reading the icy_metadata_headers and
	   icy_metadata_packet options.	 The default is	1.

       icy_metadata_headers
	   If the server supports ICY metadata,	this contains the ICY-specific
	   HTTP	reply headers, separated by newline characters.

       icy_metadata_packet
	   If the server supports ICY metadata,	and icy	was set	to 1, this
	   contains the	last non-empty metadata	packet sent by the server. It
	   should be polled in regular intervals by applications interested in
	   mid-stream metadata updates.

       offset
	   Set initial byte offset.

       end_offset
	   Try to limit	the request to bytes preceding this offset.

   Icecast
       Icecast (stream to Icecast servers)

       This protocol accepts the following options:

       ice_genre
	   Set the stream genre.

       ice_name
	   Set the stream name.

       ice_description
	   Set the stream description.

       ice_url
	   Set the stream website URL.

       ice_public
	   Set if the stream should be public or not.  The default is 0	(not
	   public).

       user_agent
	   Override the	User-Agent header. If not specified a string of	the
	   form	"Lavf/<version>" will be used.

       password
	   Set the Icecast mountpoint password.

       content_type
	   Set the stream content type.	This must be set if it is different
	   from	audio/mpeg.

       legacy_icecast
	   This	enables	support	for Icecast versions < 2.4.0, that do not
	   support the HTTP PUT	method but the SOURCE method.

   mmst
       MMS (Microsoft Media Server) protocol over TCP.

   mmsh
       MMS (Microsoft Media Server) protocol over HTTP.

       The required syntax is:

	       mmsh://<server>[:<port>][/<app>][/<playpath>]

   md5
       MD5 output protocol.

       Computes	the MD5	hash of	the data to be written,	and on close writes
       this to the designated output or	stdout if none is specified. It	can be
       used to test muxers without writing an actual file.

       Some examples follow.

	       # Write the MD5 hash of the encoded AVI file to the file	output.avi.md5.
	       avconv -i input.flv -f avi -y md5:output.avi.md5

	       # Write the MD5 hash of the encoded AVI file to stdout.
	       avconv -i input.flv -f avi -y md5:

       Note that some formats (typically MOV) require the output protocol to
       be seekable, so they will fail with the MD5 output protocol.

   pipe
       UNIX pipe access	protocol.

       Allow to	read and write from UNIX pipes.

       The accepted syntax is:

	       pipe:[<number>]

       number is the number corresponding to the file descriptor of the	pipe
       (e.g. 0 for stdin, 1 for	stdout,	2 for stderr).	If number is not
       specified, by default the stdout	file descriptor	will be	used for
       writing,	stdin for reading.

       For example to read from	stdin with avconv:

	       cat test.wav | avconv -i	pipe:0
	       # ...this is the	same as...
	       cat test.wav | avconv -i	pipe:

       For writing to stdout with avconv:

	       avconv -i test.wav -f avi pipe:1	| cat >	test.avi
	       # ...this is the	same as...
	       avconv -i test.wav -f avi pipe: | cat > test.avi

       Note that some formats (typically MOV), require the output protocol to
       be seekable, so they will fail with the pipe output protocol.

   rtmp
       Real-Time Messaging Protocol.

       The Real-Time Messaging Protocol	(RTMP) is used for streaming
       multimedia content across a TCP/IP network.

       The required syntax is:

	       rtmp://[<username>:<password>@]<server>[:<port>][/<app>][/<instance>][/<playpath>]

       The accepted parameters are:

       username
	   An optional username	(mostly	for publishing).

       password
	   An optional password	(mostly	for publishing).

       server
	   The address of the RTMP server.

       port
	   The number of the TCP port to use (by default is 1935).

       app It is the name of the application to	access.	It usually corresponds
	   to the path where the application is	installed on the RTMP server
	   (e.g. /ondemand/, /flash/live/, etc.). You can override the value
	   parsed from the URI through the "rtmp_app" option, too.

       playpath
	   It is the path or name of the resource to play with reference to
	   the application specified in	app, may be prefixed by	"mp4:".	You
	   can override	the value parsed from the URI through the
	   "rtmp_playpath" option, too.

       listen
	   Act as a server, listening for an incoming connection.

       timeout
	   Maximum time	to wait	for the	incoming connection. Implies listen.

       Additionally, the following parameters can be set via command line
       options (or in code via "AVOption"s):

       rtmp_app
	   Name	of application to connect on the RTMP server. This option
	   overrides the parameter specified in	the URI.

       rtmp_buffer
	   Set the client buffer time in milliseconds. The default is 3000.

       rtmp_conn
	   Extra arbitrary AMF connection parameters, parsed from a string,
	   e.g.	like "B:1 S:authMe O:1 NN:code:1.23 NS:flag:ok O:0".  Each
	   value is prefixed by	a single character denoting the	type, B	for
	   Boolean, N for number, S for	string,	O for object, or Z for null,
	   followed by a colon.	For Booleans the data must be either 0 or 1
	   for FALSE or	TRUE, respectively.  Likewise for Objects the data
	   must	be 0 or	1 to end or begin an object, respectively. Data	items
	   in subobjects may be	named, by prefixing the	type with 'N' and
	   specifying the name before the value	(i.e. "NB:myFlag:1"). This
	   option may be used multiple times to	construct arbitrary AMF
	   sequences.

       rtmp_flashver
	   Version of the Flash	plugin used to run the SWF player. The default
	   is LNX 9,0,124,2. (When publishing, the default is FMLE/3.0
	   (compatible;	<libavformat version>).)

       rtmp_flush_interval
	   Number of packets flushed in	the same request (RTMPT	only). The
	   default is 10.

       rtmp_live
	   Specify that	the media is a live stream. No resuming	or seeking in
	   live	streams	is possible. The default value is "any", which means
	   the subscriber first	tries to play the live stream specified	in the
	   playpath. If	a live stream of that name is not found, it plays the
	   recorded stream. The	other possible values are "live" and
	   "recorded".

       rtmp_pageurl
	   URL of the web page in which	the media was embedded.	By default no
	   value will be sent.

       rtmp_playpath
	   Stream identifier to	play or	to publish. This option	overrides the
	   parameter specified in the URI.

       rtmp_subscribe
	   Name	of live	stream to subscribe to.	By default no value will be
	   sent.  It is	only sent if the option	is specified or	if rtmp_live
	   is set to live.

       rtmp_swfhash
	   SHA256 hash of the decompressed SWF file (32	bytes).

       rtmp_swfsize
	   Size	of the decompressed SWF	file, required for SWFVerification.

       rtmp_swfurl
	   URL of the SWF player for the media.	By default no value will be
	   sent.

       rtmp_swfverify
	   URL to player swf file, compute hash/size automatically.

       rtmp_tcurl
	   URL of the target stream. Defaults to proto://host[:port]/app.

       For example to read with	avplay a multimedia resource named "sample"
       from the	application "vod" from an RTMP server "myserver":

	       avplay rtmp://myserver/vod/sample

       To publish to a password	protected server, passing the playpath and app
       names separately:

	       avconv -re -i <input> -f	flv -rtmp_playpath some/long/path -rtmp_app long/app/name rtmp://username:password@myserver/

   rtmpe
       Encrypted Real-Time Messaging Protocol.

       The Encrypted Real-Time Messaging Protocol (RTMPE) is used for
       streaming multimedia content within standard cryptographic primitives,
       consisting of Diffie-Hellman key	exchange and HMACSHA256, generating a
       pair of RC4 keys.

   rtmps
       Real-Time Messaging Protocol over a secure SSL connection.

       The Real-Time Messaging Protocol	(RTMPS)	is used	for streaming
       multimedia content across an encrypted connection.

   rtmpt
       Real-Time Messaging Protocol tunneled through HTTP.

       The Real-Time Messaging Protocol	tunneled through HTTP (RTMPT) is used
       for streaming multimedia	content	within HTTP requests to	traverse
       firewalls.

   rtmpte
       Encrypted Real-Time Messaging Protocol tunneled through HTTP.

       The Encrypted Real-Time Messaging Protocol tunneled through HTTP
       (RTMPTE)	is used	for streaming multimedia content within	HTTP requests
       to traverse firewalls.

   rtmpts
       Real-Time Messaging Protocol tunneled through HTTPS.

       The Real-Time Messaging Protocol	tunneled through HTTPS (RTMPTS)	is
       used for	streaming multimedia content within HTTPS requests to traverse
       firewalls.

   librtmp rtmp, rtmpe,	rtmps, rtmpt, rtmpte
       Real-Time Messaging Protocol and	its variants supported through
       librtmp.

       Requires	the presence of	the librtmp headers and	library	during
       configuration. You need to explicitly configure the build with
       "--enable-librtmp". If enabled this will	replace	the native RTMP
       protocol.

       This protocol provides most client functions and	a few server functions
       needed to support RTMP, RTMP tunneled in	HTTP (RTMPT), encrypted	RTMP
       (RTMPE),	RTMP over SSL/TLS (RTMPS) and tunneled variants	of these
       encrypted types (RTMPTE,	RTMPTS).

       The required syntax is:

	       <rtmp_proto>://<server>[:<port>][/<app>][/<playpath>] <options>

       where rtmp_proto	is one of the strings "rtmp", "rtmpt", "rtmpe",
       "rtmps",	"rtmpte", "rtmpts" corresponding to each RTMP variant, and
       server, port, app and playpath have the same meaning as specified for
       the RTMP	native protocol.  options contains a list of space-separated
       options of the form key=val.

       See the librtmp manual page (man	3 librtmp) for more information.

       For example, to stream a	file in	real-time to an	RTMP server using
       avconv:

	       avconv -re -i myfile -f flv rtmp://myserver/live/mystream

       To play the same	stream using avplay:

	       avplay "rtmp://myserver/live/mystream live=1"

   rtp
       Real-Time Protocol.

   rtsp
       RTSP is not technically a protocol handler in libavformat, it is	a
       demuxer and muxer. The demuxer supports both normal RTSP	(with data
       transferred over	RTP; this is used by e.g. Apple	and Microsoft) and
       Real-RTSP (with data transferred	over RDT).

       The muxer can be	used to	send a stream using RTSP ANNOUNCE to a server
       supporting it (currently	Darwin Streaming Server	and Mischa
       Spiegelmock's
	RTSP server ("http://github.com/revmischa/rtsp-server")).

       The required syntax for a RTSP url is:

	       rtsp://<hostname>[:<port>]/<path>

       The following options (set on the avconv/avplay command line, or	set in
       code via	"AVOption"s or in "avformat_open_input"), are supported:

       Flags for "rtsp_transport":

       udp Use UDP as lower transport protocol.

       tcp Use TCP (interleaving within	the RTSP control channel) as lower
	   transport protocol.

       udp_multicast
	   Use UDP multicast as	lower transport	protocol.

       http
	   Use HTTP tunneling as lower transport protocol, which is useful for
	   passing proxies.

       Multiple	lower transport	protocols may be specified, in that case they
       are tried one at	a time (if the setup of	one fails, the next one	is
       tried).	For the	muxer, only the	"tcp" and "udp"	options	are supported.

       Flags for "rtsp_flags":

       filter_src
	   Accept packets only from negotiated peer address and	port.

       listen
	   Act as a server, listening for an incoming connection.

       When receiving data over	UDP, the demuxer tries to reorder received
       packets (since they may arrive out of order, or packets may get lost
       totally). This can be disabled by setting the maximum demuxing delay to
       zero (via the "max_delay" field of AVFormatContext).

       When watching multi-bitrate Real-RTSP streams with avplay, the streams
       to display can be chosen	with "-vst" n and "-ast" n for video and audio
       respectively, and can be	switched on the	fly by pressing	"v" and	"a".

       Example command lines:

       To watch	a stream over UDP, with	a max reordering delay of 0.5 seconds:

	       avplay -max_delay 500000	-rtsp_transport	udp rtsp://server/video.mp4

       To watch	a stream tunneled over HTTP:

	       avplay -rtsp_transport http rtsp://server/video.mp4

       To send a stream	in realtime to a RTSP server, for others to watch:

	       avconv -re -i <input> -f	rtsp -muxdelay 0.1 rtsp://server/live.sdp

       To receive a stream in realtime:

	       avconv -rtsp_flags listen -i rtsp://ownaddress/live.sdp <output>

   sap
       Session Announcement Protocol (RFC 2974). This is not technically a
       protocol	handler	in libavformat,	it is a	muxer and demuxer.  It is used
       for signalling of RTP streams, by announcing the	SDP for	the streams
       regularly on a separate port.

       Muxer

       The syntax for a	SAP url	given to the muxer is:

	       sap://<destination>[:<port>][?<options>]

       The RTP packets are sent	to destination on port port, or	to port	5004
       if no port is specified.	 options is a "&"-separated list. The
       following options are supported:

       announce_addr=address
	   Specify the destination IP address for sending the announcements
	   to.	If omitted, the	announcements are sent to the commonly used
	   SAP announcement multicast address 224.2.127.254 (sap.mcast.net),
	   or ff0e::2:7ffe if destination is an	IPv6 address.

       announce_port=port
	   Specify the port to send the	announcements on, defaults to 9875 if
	   not specified.

       ttl=ttl
	   Specify the time to live value for the announcements	and RTP
	   packets, defaults to	255.

       same_port=0|1
	   If set to 1,	send all RTP streams on	the same port pair. If zero
	   (the	default), all streams are sent on unique ports,	with each
	   stream on a port 2 numbers higher than the previous.	 VLC/Live555
	   requires this to be set to 1, to be able to receive the stream.
	   The RTP stack in libavformat	for receiving requires all streams to
	   be sent on unique ports.

       Example command lines follow.

       To broadcast a stream on	the local subnet, for watching in VLC:

	       avconv -re -i <input> -f	sap sap://224.0.0.255?same_port=1

       Similarly, for watching in avplay:

	       avconv -re -i <input> -f	sap sap://224.0.0.255

       And for watching	in avplay, over	IPv6:

	       avconv -re -i <input> -f	sap sap://[ff0e::1:2:3:4]

       Demuxer

       The syntax for a	SAP url	given to the demuxer is:

	       sap://[<address>][:<port>]

       address is the multicast	address	to listen for announcements on,	if
       omitted,	the default 224.2.127.254 (sap.mcast.net) is used. port	is the
       port that is listened on, 9875 if omitted.

       The demuxers listens for	announcements on the given address and port.
       Once an announcement is received, it tries to receive that particular
       stream.

       Example command lines follow.

       To play back the	first stream announced on the normal SAP multicast
       address:

	       avplay sap://

       To play back the	first stream announced on one the default IPv6 SAP
       multicast address:

	       avplay sap://[ff0e::2:7ffe]

   tcp
       Transmission Control Protocol.

       The required syntax for a TCP url is:

	       tcp://<hostname>:<port>[?<options>]

       listen
	   Listen for an incoming connection

		   avconv -i <input> -f	<format> tcp://<hostname>:<port>?listen
		   avplay tcp://<hostname>:<port>

   tls
       Transport Layer Security	(TLS) /	Secure Sockets Layer (SSL)

       The required syntax for a TLS url is:

	       tls://<hostname>:<port>

       The following parameters	can be set via command line options (or	in
       code via	"AVOption"s):

       ca_file
	   A file containing certificate authority (CA)	root certificates to
	   treat as trusted. If	the linked TLS library contains	a default this
	   might not need to be	specified for verification to work, but	not
	   all libraries and setups have defaults built	in.

       tls_verify=1|0
	   If enabled, try to verify the peer that we are communicating	with.
	   Note, if using OpenSSL, this	currently only makes sure that the
	   peer	certificate is signed by one of	the root certificates in the
	   CA database,	but it does not	validate that the certificate actually
	   matches the host name we are	trying to connect to. (With GnuTLS,
	   the host name is validated as well.)

	   This	is disabled by default since it	requires a CA database to be
	   provided by the caller in many cases.

       cert_file
	   A file containing a certificate to use in the handshake with	the
	   peer.  (When	operating as server, in	listen mode, this is more
	   often required by the peer, while client certificates only are
	   mandated in certain setups.)

       key_file
	   A file containing the private key for the certificate.

       listen=1|0
	   If enabled, listen for connections on the provided port, and	assume
	   the server role in the handshake instead of the client role.

   udp
       User Datagram Protocol.

       The required syntax for a UDP url is:

	       udp://<hostname>:<port>[?<options>]

       options contains	a list of &-separated options of the form key=val.
       Follow the list of supported options.

       buffer_size=size
	   set the UDP buffer size in bytes

       localport=port
	   override the	local UDP port to bind with

       localaddr=addr
	   Choose the local IP address.	This is	useful e.g. if sending
	   multicast and the host has multiple interfaces, where the user can
	   choose which	interface to send on by	specifying the IP address of
	   that	interface.

       pkt_size=size
	   set the size	in bytes of UDP	packets

       reuse=1|0
	   explicitly allow or disallow	reusing	UDP sockets

       ttl=ttl
	   set the time	to live	value (for multicast only)

       connect=1|0
	   Initialize the UDP socket with "connect()". In this case, the
	   destination address can't be	changed	with ff_udp_set_remote_url
	   later.  If the destination address isn't known at the start,	this
	   option can be specified in ff_udp_set_remote_url, too.  This	allows
	   finding out the source address for the packets with getsockname,
	   and makes writes return with	AVERROR(ECONNREFUSED) if "destination
	   unreachable"	is received.  For receiving, this gives	the benefit of
	   only	receiving packets from the specified peer address/port.

       sources=address[,address]
	   Only	receive	packets	sent to	the multicast group from one of	the
	   specified sender IP addresses.

       block=address[,address]
	   Ignore packets sent to the multicast	group from the specified
	   sender IP addresses.

       Some usage examples of the udp protocol with avconv follow.

       To stream over UDP to a remote endpoint:

	       avconv -i <input> -f <format> udp://<hostname>:<port>

       To stream in mpegts format over UDP using 188 sized UDP packets,	using
       a large input buffer:

	       avconv -i <input> -f mpegts udp://<hostname>:<port>?pkt_size=188&buffer_size=65535

       To receive over UDP from	a remote endpoint:

	       avconv -i udp://[<multicast-address>]:<port>

   unix
       Unix local socket

       The required syntax for a Unix socket URL is:

	       unix://<filepath>

       The following parameters	can be set via command line options (or	in
       code via	"AVOption"s):

       timeout
	   Timeout in ms.

       listen
	   Create the Unix socket in listening mode.

INPUT DEVICES
       Input devices are configured elements in	Libav which allow to access
       the data	coming from a multimedia device	attached to your system.

       When you	configure your Libav build, all	the supported input devices
       are enabled by default. You can list all	available ones using the
       configure option	"--list-indevs".

       You can disable all the input devices using the configure option
       "--disable-indevs", and selectively enable an input device using	the
       option "--enable-indev=INDEV", or you can disable a particular input
       device using the	option "--disable-indev=INDEV".

       The option "-formats" of	the av*	tools will display the list of
       supported input devices (amongst	the demuxers).

       A description of	the currently available	input devices follows.

   alsa
       ALSA (Advanced Linux Sound Architecture)	input device.

       To enable this input device during configuration	you need libasound
       installed on your system.

       This device allows capturing from an ALSA device. The name of the
       device to capture has to	be an ALSA card	identifier.

       An ALSA identifier has the syntax:

	       hw:<CARD>[,<DEV>[,<SUBDEV>]]

       where the DEV and SUBDEV	components are optional.

       The three arguments (in order: CARD,DEV,SUBDEV) specify card number or
       identifier, device number and subdevice number (-1 means	any).

       To see the list of cards	currently recognized by	your system check the
       files /proc/asound/cards	and /proc/asound/devices.

       For example to capture with avconv from an ALSA device with card	id 0,
       you may run the command:

	       avconv -f alsa -i hw:0 alsaout.wav

       For more	information see:
       <http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html>

   bktr
       BSD video input device.

   dv1394
       Linux DV	1394 input device.

   fbdev
       Linux framebuffer input device.

       The Linux framebuffer is	a graphic hardware-independent abstraction
       layer to	show graphics on a computer monitor, typically on the console.
       It is accessed through a	file device node, usually /dev/fb0.

       For more	detailed information read the file
       Documentation/fb/framebuffer.txt	included in the	Linux source tree.

       To record from the framebuffer device /dev/fb0 with avconv:

	       avconv -f fbdev -r 10 -i	/dev/fb0 out.avi

       You can take a single screenshot	image with the command:

	       avconv -f fbdev -frames:v 1 -r 1	-i /dev/fb0 screenshot.jpeg

       See also	<http://linux-fbdev.sourceforge.net/>, and fbset(1).

   jack
       JACK input device.

       To enable this input device during configuration	you need libjack
       installed on your system.

       A JACK input device creates one or more JACK writable clients, one for
       each audio channel, with	name client_name:input_N, where	client_name is
       the name	provided by the	application, and N is a	number which
       identifies the channel.	Each writable client will send the acquired
       data to the Libav input device.

       Once you	have created one or more JACK readable clients,	you need to
       connect them to one or more JACK	writable clients.

       To connect or disconnect	JACK clients you can use the jack_connect and
       jack_disconnect programs, or do it through a graphical interface, for
       example with qjackctl.

       To list the JACK	clients	and their properties you can invoke the
       command jack_lsp.

       Follows an example which	shows how to capture a JACK readable client
       with avconv.

	       # Create	a JACK writable	client with name "libav".
	       $ avconv	-f jack	-i libav -y out.wav

	       # Start the sample jack_metro readable client.
	       $ jack_metro -b 120 -d 0.2 -f 4000

	       # List the current JACK clients.
	       $ jack_lsp -c
	       system:capture_1
	       system:capture_2
	       system:playback_1
	       system:playback_2
	       libav:input_1
	       metro:120_bpm

	       # Connect metro to the avconv writable client.
	       $ jack_connect metro:120_bpm libav:input_1

       For more	information read: <http://jackaudio.org/>

   libdc1394
       IIDC1394	input device, based on libdc1394 and libraw1394.

   oss
       Open Sound System input device.

       The filename to provide to the input device is the device node
       representing the	OSS input device, and is usually set to	/dev/dsp.

       For example to grab from	/dev/dsp using avconv use the command:

	       avconv -f oss -i	/dev/dsp /tmp/oss.wav

       For more	information about OSS see:
       <http://manuals.opensound.com/usersguide/dsp.html>

   pulse
       pulseaudio input	device.

       To enable this input device during configuration	you need libpulse-
       simple installed	in your	system.

       The filename to provide to the input device is a	source device or the
       string "default"

       To list the pulse source	devices	and their properties you can invoke
       the command pactl list sources.

	       avconv -f pulse -i default /tmp/pulse.wav

       server AVOption

       The syntax is:

	       -server <server name>

       Connects	to a specific server.

       name AVOption

       The syntax is:

	       -name <application name>

       Specify the application name pulse will use when	showing	active
       clients,	by default it is "libav"

       stream_name AVOption

       The syntax is:

	       -stream_name <stream name>

       Specify the stream name pulse will use when showing active streams, by
       default it is "record"

       sample_rate AVOption

       The syntax is:

	       -sample_rate <samplerate>

       Specify the samplerate in Hz, by	default	48kHz is used.

       channels	AVOption

       The syntax is:

	       -channels <N>

       Specify the channels in use, by default 2 (stereo) is set.

       frame_size AVOption

       The syntax is:

	       -frame_size <bytes>

       Specify the number of byte per frame, by	default	it is set to 1024.

       fragment_size AVOption

       The syntax is:

	       -fragment_size <bytes>

       Specify the minimal buffering fragment in pulseaudio, it	will affect
       the audio latency. By default it	is unset.

   sndio
       sndio input device.

       To enable this input device during configuration	you need libsndio
       installed on your system.

       The filename to provide to the input device is the device node
       representing the	sndio input device, and	is usually set to /dev/audio0.

       For example to grab from	/dev/audio0 using avconv use the command:

	       avconv -f sndio -i /dev/audio0 /tmp/oss.wav

   video4linux2
       Video4Linux2 input video	device.

       The name	of the device to grab is a file	device node, usually Linux
       systems tend to automatically create such nodes when the	device (e.g.
       an USB webcam) is plugged into the system, and has a name of the	kind
       /dev/videoN, where N is a number	associated to the device.

       Video4Linux2 devices usually support a limited set of widthxheight
       sizes and framerates. You can check which are supported using
       -list_formats all for Video4Linux2 devices.

       Some usage examples of the video4linux2 devices with avconv and avplay:

	       # List supported	formats	for a video4linux2 device.
	       avplay -f video4linux2 -list_formats all	/dev/video0

	       # Grab and show the input of a video4linux2 device.
	       avplay -f video4linux2 -framerate 30 -video_size	hd720 /dev/video0

	       # Grab and record the input of a	video4linux2 device, leave the
	       framerate and size as previously	set.
	       avconv -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg

   vfwcap
       VfW (Video for Windows) capture input device.

       The filename passed as input is the capture driver number, ranging from
       0 to 9. You may use "list" as filename to print a list of drivers. Any
       other filename will be interpreted as device number 0.

   x11grab
       X11 video input device.

       This device allows to capture a region of an X11	display.

       The filename passed as input has	the syntax:

	       [<hostname>]:<display_number>.<screen_number>[+<x_offset>,<y_offset>]

       hostname:display_number.screen_number specifies the X11 display name of
       the screen to grab from.	hostname can be	omitted, and defaults to
       "localhost". The	environment variable DISPLAY contains the default
       display name.

       x_offset	and y_offset specify the offsets of the	grabbed	area with
       respect to the top-left border of the X11 screen. They default to 0.

       Check the X11 documentation (e.g. man X)	for more detailed information.

       Use the dpyinfo program for getting basic information about the
       properties of your X11 display (e.g. grep for "name" or "dimensions").

       For example to grab from	:0.0 using avconv:

	       avconv -f x11grab -r 25 -s cif -i :0.0 out.mpg

	       # Grab at position 10,20.
	       avconv -f x11grab -r 25 -s cif -i :0.0+10,20 out.mpg

       follow_mouse AVOption

       The syntax is:

	       -follow_mouse centered|<PIXELS>

       When it is specified with "centered", the grabbing region follows the
       mouse pointer and keeps the pointer at the center of region; otherwise,
       the region follows only when the	mouse pointer reaches within PIXELS
       (greater	than zero) to the edge of region.

       For example:

	       avconv -f x11grab -follow_mouse centered	-r 25 -s cif -i	:0.0 out.mpg

	       # Follows only when the mouse pointer reaches within 100	pixels to edge
	       avconv -f x11grab -follow_mouse 100 -r 25 -s cif	-i :0.0	out.mpg

       show_region AVOption

       The syntax is:

	       -show_region 1

       If show_region AVOption is specified with 1, then the grabbing region
       will be indicated on screen. With this option, it's easy	to know	what
       is being	grabbed	if only	a portion of the screen	is grabbed.

       For example:

	       avconv -f x11grab -show_region 1	-r 25 -s cif -i	:0.0+10,20 out.mpg

	       # With follow_mouse
	       avconv -f x11grab -follow_mouse centered	-show_region 1	-r 25 -s cif -i	:0.0 out.mpg

       grab_x grab_y AVOption

       The syntax is:

	       -grab_x <x_offset> -grab_y <y_offset>

       Set the grabbing	region coordinates. The	are expressed as offset	from
       the top left corner of the X11 window. The default value	is 0.

SEE ALSO
       avconv(1), avplay(1) and	the Libav HTML documentation

AUTHORS
       The Libav developers

				  2020-08-31			    AVPROBE(1)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | DEMUXERS | MUXERS | PROTOCOLS | INPUT DEVICES | SEE ALSO | AUTHORS

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