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FFMPEG-CODECS(1)					      FFMPEG-CODECS(1)

NAME
       ffmpeg-codecs - FFmpeg codecs

DESCRIPTION
       This document describes the codecs (decoders and	encoders) provided by
       the libavcodec library.

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

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

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

       The list	of supported options follow:

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

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

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

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

	   Possible values:

	   mv4 Use four	motion vector by macroblock (mpeg4).

	   qpel
	       Use 1/4 pel motion compensation.

	   loop
	       Use loop	filter.

	   qscale
	       Use fixed qscale.

	   gmc Use gmc.

	   mv0 Always try a mb with mv=<0,0>.

	   input_preserved
	   pass1
	       Use internal 2pass ratecontrol in first pass mode.

	   pass2
	       Use internal 2pass ratecontrol in second	pass mode.

	   gray
	       Only decode/encode grayscale.

	   emu_edge
	       Do not draw edges.

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

	   aic Apply H263 advanced intra coding	/ mpeg4	ac prediction.

	   cbp Deprecated, use mpegvideo private options instead.

	   qprd
	       Deprecated, use mpegvideo private options instead.

	   ilme
	       Apply interlaced	motion estimation.

	   cgop
	       Use closed gop.

       me_method integer (encoding,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 dia 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

	   iter
	       iter motion estimation

       extradata_size integer
	   Set extradata size.

       time_base rational number
	   Set codec time base.

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

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

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

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

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

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

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

       frame_number integer
	   Set the frame number.

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

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

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

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

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

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

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

	   Default value is 0.

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

       rc_strategy integer (encoding,video)
	   Set ratecontrol method.

       b_strategy integer (encoding,video)
	   Set strategy	to choose between I/P/B-frames.

       ps integer (encoding,video)
	   Set RTP payload size	in bytes.

       mv_bits integer
       header_bits integer
       i_tex_bits integer
       p_tex_bits integer
       i_count integer
       p_count integer
       skip_count integer
       misc_bits integer
       frame_bits integer
       codec_tag integer
       bug flags (decoding,video)
	   Workaround not auto detected	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  Workaround various bugs in microsoft broken decoders.

	   trunc
	       trancated frames

       lelim integer (encoding,video)
	   Set single coefficient elimination threshold	for luminance
	   (negative values also consider DC coefficient).

       celim integer (encoding,video)
	   Set single coefficient elimination threshold	for chrominance
	   (negative values also consider dc coefficient)

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

	   Possible values:

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

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

	   normal
	   unofficial
	       allow unofficial	extensions

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

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

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

	   Possible values:

	   crccheck
	       verify embedded CRCs

	   bitstream
	       detect bitstream	specification deviations

	   buffer
	       detect improper bitstream length

	   explode
	       abort decoding on minor error detection

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

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

	   compliant
	       consider	all spec non compliancies as errors

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

       has_b_frames integer
       block_align integer
       mpeg_quant integer (encoding,video)
	   Use MPEG quantizers instead of H.263.

       qsquish float (encoding,video)
	   How to keep quantizer between qmin and qmax (0 = clip, 1 = use
	   differentiable function).

       rc_qmod_amp float (encoding,video)
	   Set experimental quantizer modulation.

       rc_qmod_freq integer (encoding,video)
	   Set experimental quantizer modulation.

       rc_override_count integer
       rc_eq string (encoding,video)
	   Set rate control equation. When computing the expression, besides
	   the standard	functions defined in the section 'Expression
	   Evaluation',	the following functions	are available: bits2qp(bits),
	   qp2bits(qp).	Also the following constants are available: iTex pTex
	   tex mv fCode	iCount mcVar var isI isP isB avgQP qComp avgIITex
	   avgPITex avgPPTex avgBPTex avgTex.

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

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

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

       rc_buf_aggressivity float (encoding,video)
	   Currently useless.

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

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

       rc_init_cplx float (encoding,video)
	   Set initial complexity for 1-pass encoding.

       dct integer (encoding,video)
	   Set DCT algorithm.

	   Possible values:

	   auto
	       autoselect a good one (default)

	   fastint
	       fast integer

	   int accurate	integer

	   mmx
	   altivec
	   faan
	       floating	point AAN DCT

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

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

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

       p_mask float (encoding,video)
	   Set inter masking.

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

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

	   Possible values:

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

	   arm
	   altivec
	   sh4
	   simplearm
	   simplearmv5te
	   simplearmv6
	   simpleneon
	   simplealpha
	   ipp
	   xvidmmx
	   faani
	       floating	point AAN IDCT

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

	   Possible values:

	   guess_mvs
	       iterative motion	vector (MV) search (slow)

	   deblock
	       use strong deblock filter for damaged MBs

	   favor_inter
	       favor predicting	from the previous frame	instead	of the current

       bits_per_coded_sample integer
       pred integer (encoding,video)
	   Set prediction method.

	   Possible values:

	   left
	   plane
	   median
       aspect rational number (encoding,video)
	   Set sample aspect ratio.

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

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

	   Possible values:

	   pict
	       picture info

	   rc  rate control

	   bitstream
	   mb_type
	       macroblock (MB) type

	   qp  per-block quantization parameter	(QP)

	   mv  motion vector

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

	   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

	   nomc
	       skip motion compensation

       vismv integer (decoding,video)
	   Visualize motion vectors (MVs).

	   This	option is deprecated, see the codecview	filter instead.

	   Possible values:

	   pf  forward predicted MVs of	P-frames

	   bf  forward predicted MVs of	B-frames

	   bb  backward	predicted MVs of B-frames

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

	   Possible values:

	   sad sum of absolute differences, fast (default)

	   sse sum of squared errors

	   satd
	       sum of absolute Hadamard	transformed differences

	   dct sum of absolute DCT transformed differences

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

	   bit number of bits needed for the block

	   rd  rate distortion optimal,	slow

	   zero
	       0

	   vsad
	       sum of absolute vertical	differences

	   vsse
	       sum of squared vertical differences

	   nsse
	       noise preserving	sum of squared differences

	   w53 5/3 wavelet, only used in snow

	   w97 9/7 wavelet, only used in snow

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

	   Possible values:

	   sad sum of absolute differences, fast (default)

	   sse sum of squared errors

	   satd
	       sum of absolute Hadamard	transformed differences

	   dct sum of absolute DCT transformed differences

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

	   bit number of bits needed for the block

	   rd  rate distortion optimal,	slow

	   zero
	       0

	   vsad
	       sum of absolute vertical	differences

	   vsse
	       sum of squared vertical differences

	   nsse
	       noise preserving	sum of squared differences

	   w53 5/3 wavelet, only used in snow

	   w97 9/7 wavelet, only used in snow

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

	   Possible values:

	   sad sum of absolute differences, fast (default)

	   sse sum of squared errors

	   satd
	       sum of absolute Hadamard	transformed differences

	   dct sum of absolute DCT transformed differences

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

	   bit number of bits needed for the block

	   rd  rate distortion optimal,	slow

	   zero
	       0

	   vsad
	       sum of absolute vertical	differences

	   vsse
	       sum of squared vertical differences

	   nsse
	       noise preserving	sum of squared differences

	   w53 5/3 wavelet, only used in snow

	   w97 9/7 wavelet, only used in snow

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

	   Possible values:

	   sad sum of absolute differences, fast (default)

	   sse sum of squared errors

	   satd
	       sum of absolute Hadamard	transformed differences

	   dct sum of absolute DCT transformed differences

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

	   bit number of bits needed for the block

	   rd  rate distortion optimal,	slow

	   zero
	       0

	   vsad
	       sum of absolute vertical	differences

	   vsse
	       sum of squared vertical differences

	   nsse
	       noise preserving	sum of squared differences

	   w53 5/3 wavelet, only used in snow

	   w97 9/7 wavelet, only used in snow

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

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

       preme integer (encoding,video)
	   Set pre motion estimation.

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

	   Possible values:

	   sad sum of absolute differences, fast (default)

	   sse sum of squared errors

	   satd
	       sum of absolute Hadamard	transformed differences

	   dct sum of absolute DCT transformed differences

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

	   bit number of bits needed for the block

	   rd  rate distortion optimal,	slow

	   zero
	       0

	   vsad
	       sum of absolute vertical	differences

	   vsse
	       sum of squared vertical differences

	   nsse
	       noise preserving	sum of squared differences

	   w53 5/3 wavelet, only used in snow

	   w97 9/7 wavelet, only used in snow

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

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

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

       ibias integer (encoding,video)
	   Set intra quant bias.

       pbias integer (encoding,video)
	   Set inter quant bias.

       color_table_id integer
       global_quality integer (encoding,audio,video)
       coder integer (encoding,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 integer (encoding,video)
	   Set context model.

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

	   Possible values:

	   simple
	       use mbcmp (default)

	   bits
	       use fewest bits

	   rd  use best	rate distortion

       stream_codec_tag	integer
       sc_threshold integer (encoding,video)
	   Set scene change threshold.

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

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

       nr integer (encoding,video)
	   Set noise reduction.

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

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

	   fast
	       Allow non spec compliant	speedup	tricks.

	   sgop
	       Deprecated, use mpegvideo private options instead.

	   noout
	       Skip bitstream encoding.

	   ignorecrop
	       Ignore cropping information from	sps.

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

	   chunks
	       Frame data might	be split into multiple chunks.

	   showall
	       Show all	frames before the first	keyframe.

	   skiprd
	       Deprecated, use mpegvideo private options instead.

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

       error integer (encoding,video)
       qns integer (encoding,video)
	   Deprecated, use mpegvideo private options instead.

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

	   Possible values:

	   auto, 0
	       automatically select the	number of threads to set

	   Default value is auto.

       me_threshold integer (encoding,video)
	   Set motion estimation threshold.

       mb_threshold integer (encoding,video)
	   Set macroblock threshold.

       dc integer (encoding,video)
	   Set intra_dc_precision.

       nssew integer (encoding,video)
	   Set nsse weight.

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

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

       profile integer (encoding,audio,video)
	   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
	   mpeg4_sp
	   mpeg4_core
	   mpeg4_main
	   mpeg4_asp
	   dts
	   dts_es
	   dts_96_24
	   dts_hd_hra
	   dts_hd_ma
       level integer (encoding,audio,video)
	   Possible values:

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

       skip_threshold integer (encoding,video)
	   Set frame skip threshold.

       skip_factor integer (encoding,video)
	   Set frame skip factor.

       skip_exp	integer	(encoding,video)
	   Set frame skip exponent.  Negative values behave identical to the
	   corresponding positive ones,	except that the	score is normalized.
	   Positive values exist primarily for compatibility reasons and are
	   not so useful.

       skipcmp integer (encoding,video)
	   Set 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

	   w53 5/3 wavelet, only used in snow

	   w97 9/7 wavelet, only used in snow

	   dctmax
	   chroma
       border_mask float (encoding,video)
	   Increase the	quantizer for macroblocks close	to borders.

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

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

       mepc integer (encoding,video)
	   Set motion estimation bitrate penalty compensation (1.0 = 256).

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

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

	   Possible values:

	   none
	       Discard no frame.

	   default
	       Discard useless frames like 0-sized frames.

	   noref
	       Discard all non-reference frames.

	   bidir
	       Discard all bidirectional frames.

	   nokey
	       Discard all frames excepts keyframes.

	   all Discard all frames.

	   Default value is default.

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

       brd_scale integer (encoding,video)
	   Downscale frames for	dynamic	B-frame	decision.

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

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

       chromaoffset integer (encoding,video)
	   Set chroma qp offset	from luma.

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

       sc_factor integer (encoding,video)
	   Set value multiplied	by qscale for each frame and added to
	   scene_change_score.

       mv0_threshold integer (encoding,video)
       b_sensitivity integer (encoding,video)
	   Adjust sensitivity of b_frame_strategy 1.

       compression_level integer (encoding,audio,video)
       min_prediction_order integer (encoding,audio)
       max_prediction_order integer (encoding,audio)
       timecode_frame_start integer (encoding,video)
	   Set GOP timecode frame start	number,	in non drop frame format.

       request_channels	integer	(decoding,audio)
	   Set desired number of audio channels.

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

       request_channel_layout integer (decoding,audio)
	   Possible values:

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

	   bt709
	       BT.709

	   bt470m
	       BT.470 M

	   bt470bg
	       BT.470 BG

	   smpte170m
	       SMPTE 170 M

	   smpte240m
	       SMPTE 240 M

	   film
	       Film

	   bt2020
	       BT.2020

	   smpte428
	   smpte428_1
	       SMPTE ST	428-1

	   smpte431
	       SMPTE 431-2

	   smpte432
	       SMPTE 432-1

	   jedec-p22
	       JEDEC P22

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

	   bt709
	       BT.709

	   gamma22
	       BT.470 M

	   gamma28
	       BT.470 BG

	   smpte170m
	       SMPTE 170 M

	   smpte240m
	       SMPTE 240 M

	   linear
	       Linear

	   log
	   log100
	       Log

	   log_sqrt
	   log316
	       Log square root

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

	   bt1361
	   bt1361e
	       BT.1361

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

	   bt2020_10
	   bt2020_10bit
	       BT.2020 - 10 bit

	   bt2020_12
	   bt2020_12bit
	       BT.2020 - 12 bit

	   smpte2084
	       SMPTE ST	2084

	   smpte428
	   smpte428_1
	       SMPTE ST	428-1

	   arib-std-b67
	       ARIB STD-B67

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

	   rgb RGB

	   bt709
	       BT.709

	   fcc FCC

	   bt470bg
	       BT.470 BG

	   smpte170m
	       SMPTE 170 M

	   smpte240m
	       SMPTE 240 M

	   ycocg
	       YCOCG

	   bt2020nc
	   bt2020_ncl
	       BT.2020 NCL

	   bt2020c
	   bt2020_cl
	       BT.2020 CL

	   smpte2085
	       SMPTE 2085

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

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

	   pc
	   jpeg
	       JPEG (2^n-1)

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

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

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

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

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

	   Possible values:

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

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

	   frame
	       Decode more than	one frame at once.

	   Default value is slice+frame.

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

	   Possible values:

	   ma  Main Audio Service

	   ef  Effects

	   vi  Visually	Impaired

	   hi  Hearing Impaired

	   di  Dialogue

	   co  Commentary

	   em  Emergency

	   vo  Voice Over

	   ka  Karaoke

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

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

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

	   progressive
	       Progressive video

	   tt  Interlaced video, top field coded and displayed first

	   bb  Interlaced video, bottom	field coded and	displayed first

	   tb  Interlaced video, top coded first, bottom displayed first

	   bt  Interlaced video, bottom	coded first, top displayed first

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

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

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

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

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

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

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

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

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

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

   hevc
       HEVC / H.265 decoder.

       Note: the skip_loop_filter option has effect only at level "all".

   rawvideo
       Raw video decoder.

       This decoder decodes rawvideo streams.

       Options

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

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

	   0   bottom-field-first is assumed

	   1   top-field-first is assumed

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

   ac3
       AC-3 audio decoder.

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

       AC-3 Decoder Options

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

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

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

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

   flac
       FLAC audio decoder.

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

       FLAC Decoder options

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

   ffwavesynth
       Internal	wave synthetizer.

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

   libcelt
       libcelt decoder wrapper.

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

   libgsm
       libgsm decoder wrapper.

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

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

   libilbc
       libilbc decoder wrapper.

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

       Options

       The following option is supported by the	libilbc	wrapper.

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

   libopencore-amrnb
       libopencore-amrnb decoder wrapper.

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

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

   libopencore-amrwb
       libopencore-amrwb decoder wrapper.

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

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

   libopus
       libopus decoder wrapper.

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

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

SUBTITLES DECODERS
   dvbsub
       Options

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

	   0   Never compute CLUT

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

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

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

       Options

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

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

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

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

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

       Options

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

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

       txt_format
	   Specifies the format	of the decoded subtitles. The teletext decoder
	   is capable of decoding the teletext pages to	bitmaps	or to simple
	   text, you should use	"bitmap" for teletext pages, because certain
	   graphics and	colors cannot be expressed in simple text. You might
	   use "text" for teletext based subtitles if your application can
	   handle simple text based subtitles. Default value is	bitmap.

       txt_left
	   X offset of generated bitmaps, default is 0.

       txt_top
	   Y offset of generated bitmaps, default is 0.

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

       txt_duration
	   Sets	the display duration of	the decoded teletext pages or
	   subtitles in	milliseconds. Default value is 30000 which is 30
	   seconds.

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

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

ENCODERS
       Encoders	are configured elements	in FFmpeg which	allow the encoding of
       multimedia streams.

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

       You can disable all the encoders	with the configure option
       "--disable-encoders" and	selectively enable / disable single encoders
       with the	options	"--enable-encoder=ENCODER" /
       "--disable-encoder=ENCODER".

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

AUDIO ENCODERS
       A description of	some of	the currently available	audio encoders
       follows.

   aac
       Advanced	Audio Coding (AAC) encoder.

       This encoder is the default AAC encoder,	natively implemented into
       FFmpeg. Its quality is on par or	better than libfdk_aac at the default
       bitrate of 128kbps.  This encoder also implements more options,
       profiles	and samplerates	than other encoders (with only the AAC-HE
       profile pending to be implemented) so this encoder has become the
       default and is the recommended choice.

       Options

       b   Set bit rate	in bits/s. Setting this	automatically activates
	   constant bit	rate (CBR) mode. If this option	is unspecified it is
	   set to 128kbps.

       q   Set quality for variable bit	rate (VBR) mode. This option is	valid
	   only	using the ffmpeg command-line tool. For	library	interface
	   users, use global_quality.

       cutoff
	   Set cutoff frequency. If unspecified	will allow the encoder to
	   dynamically adjust the cutoff to improve clarity on low bitrates.

       aac_coder
	   Set AAC encoder coding method. Possible values:

	   twoloop
	       Two loop	searching (TLS)	method.

	       This method first sets quantizers depending on band thresholds
	       and then	tries to find an optimal combination by	adding or
	       subtracting a specific value from all quantizers	and adjusting
	       some individual quantizer a little.  Will tune itself based on
	       whether aac_is, aac_ms and aac_pns are enabled.	This is	the
	       default choice for a coder.

	   anmr
	       Average noise to	mask ratio (ANMR) trellis-based	solution.

	       This is an experimental coder which currently produces a	lower
	       quality,	is more	unstable and is	slower than the	default
	       twoloop coder but has potential.	 Currently has no support for
	       the aac_is or aac_pns options.  Not currently recommended.

	   fast
	       Constant	quantizer method.

	       This method sets	a constant quantizer for all bands. This is
	       the fastest of all the methods and has no rate control or
	       support for aac_is or aac_pns.  Not recommended.

       aac_ms
	   Sets	mid/side coding	mode. The default value	of "auto" will
	   automatically use M/S with bands which will benefit from such
	   coding. Can be forced for all bands using the value "enable", which
	   is mainly useful for	debugging or disabled using "disable".

       aac_is
	   Sets	intensity stereo coding	tool usage. By default,	it's enabled
	   and will automatically toggle IS for	similar	pairs of stereo	bands
	   if it's benefitial.	Can be disabled	for debugging by setting the
	   value to "disable".

       aac_pns
	   Uses	perceptual noise substitution to replace low entropy high
	   frequency bands with	imperceivable white noise during the decoding
	   process. By default,	it's enabled, but can be disabled for
	   debugging purposes by using "disable".

       aac_tns
	   Enables the use of a	multitap FIR filter which spans	through	the
	   high	frequency bands	to hide	quantization noise during the encoding
	   process and is reverted by the decoder. As well as decreasing
	   unpleasant artifacts	in the high range this also reduces the
	   entropy in the high bands and allows	for more bits to be used by
	   the mid-low bands. By default it's enabled but can be disabled for
	   debugging by	setting	the option to "disable".

       aac_ltp
	   Enables the use of the long term prediction extension which
	   increases coding efficiency in very low bandwidth situations	such
	   as encoding of voice	or solo	piano music by extending constant
	   harmonic peaks in bands throughout frames. This option is implied
	   by profile:a	aac_low	and is incompatible with aac_pred. Use in
	   conjunction with -ar	to decrease the	samplerate.

       aac_pred
	   Enables the use of a	more traditional style of prediction where the
	   spectral coefficients transmitted are replaced by the difference of
	   the current coefficients minus the previous "predicted"
	   coefficients. In theory and sometimes in practice this can improve
	   quality for low to mid bitrate audio.  This option implies the
	   aac_main profile and	is incompatible	with aac_ltp.

       profile
	   Sets	the encoding profile, possible values:

	   aac_low
	       The default, AAC	"Low-complexity" profile. Is the most
	       compatible and produces decent quality.

	   mpeg2_aac_low
	       Equivalent to "-profile:a aac_low -aac_pns 0". PNS was
	       introduced with the MPEG4 specifications.

	   aac_ltp
	       Long term prediction profile, is	enabled	by and will enable the
	       aac_ltp option. Introduced in MPEG4.

	   aac_main
	       Main-type prediction profile, is	enabled	by and will enable the
	       aac_pred	option.	Introduced in MPEG2.

	   If this option is unspecified it is set to aac_low.

   ac3 and ac3_fixed
       AC-3 audio encoders.

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

       The ac3 encoder uses floating-point math, while the ac3_fixed encoder
       only uses fixed-point integer math. This	does not mean that one is
       always faster, just that	one or the other may be	better suited to a
       particular system. The floating-point encoder will generally produce
       better quality audio for	a given	bitrate. The ac3_fixed encoder is not
       the default codec for any of the	output formats,	so it must be
       specified explicitly using the option "-acodec ac3_fixed" in order to
       use it.

       AC-3 Metadata

       The AC-3	metadata options are used to set parameters that describe the
       audio, but in most cases	do not affect the audio	encoding itself. Some
       of the options do directly affect or influence the decoding and
       playback	of the resulting bitstream, while others are just for
       informational purposes. A few of	the options will add bits to the
       output stream that could	otherwise be used for audio data, and will
       thus affect the quality of the output. Those will be indicated
       accordingly with	a note in the option list below.

       These parameters	are described in detail	in several publicly-available
       documents.

       *<<http://www.atsc.org/cms/standards/a_52-2010.pdf>>
       *<<http://www.atsc.org/cms/standards/a_54a_with_corr_1.pdf>>
       *<<http://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/18_Metadata.Guide.pdf>>
       *<<http://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/46_DDEncodingGuidelines.pdf>>

       Metadata	Control	Options

       -per_frame_metadata boolean
	   Allow Per-Frame Metadata. Specifies if the encoder should check for
	   changing metadata for each frame.

	   0   The metadata values set at initialization will be used for
	       every frame in the stream. (default)

	   1   Metadata	values can be changed before encoding each frame.

       Downmix Levels

       -center_mixlev level
	   Center Mix Level. The amount	of gain	the decoder should apply to
	   the center channel when downmixing to stereo. This field will only
	   be written to the bitstream if a center channel is present. The
	   value is specified as a scale factor. There are 3 valid values:

	   0.707
	       Apply -3dB gain

	   0.595
	       Apply -4.5dB gain (default)

	   0.500
	       Apply -6dB gain

       -surround_mixlev	level
	   Surround Mix	Level. The amount of gain the decoder should apply to
	   the surround	channel(s) when	downmixing to stereo. This field will
	   only	be written to the bitstream if one or more surround channels
	   are present.	The value is specified as a scale factor.  There are 3
	   valid values:

	   0.707
	       Apply -3dB gain

	   0.500
	       Apply -6dB gain (default)

	   0.000
	       Silence Surround	Channel(s)

       Audio Production	Information

       Audio Production	Information is optional	information describing the
       mixing environment.  Either none	or both	of the fields are written to
       the bitstream.

       -mixing_level number
	   Mixing Level. Specifies peak	sound pressure level (SPL) in the
	   production environment when the mix was mastered. Valid values are
	   80 to 111, or -1 for	unknown	or not indicated. The default value is
	   -1, but that	value cannot be	used if	the Audio Production
	   Information is written to the bitstream. Therefore, if the
	   "room_type" option is not the default value,	the "mixing_level"
	   option must not be -1.

       -room_type type
	   Room	Type. Describes	the equalization used during the final mixing
	   session at the studio or on the dubbing stage. A large room is a
	   dubbing stage with the industry standard X-curve equalization; a
	   small room has flat equalization.  This field will not be written
	   to the bitstream if both the	"mixing_level" option and the
	   "room_type" option have the default values.

	   0
	   notindicated
	       Not Indicated (default)

	   1
	   large
	       Large Room

	   2
	   small
	       Small Room

       Other Metadata Options

       -copyright boolean
	   Copyright Indicator.	Specifies whether a copyright exists for this
	   audio.

	   0
	   off No Copyright Exists (default)

	   1
	   on  Copyright Exists

       -dialnorm value
	   Dialogue Normalization. Indicates how far the average dialogue
	   level of the	program	is below digital 100% full scale (0 dBFS).
	   This	parameter determines a level shift during audio	reproduction
	   that	sets the average volume	of the dialogue	to a preset level. The
	   goal	is to match volume level between program sources. A value of
	   -31dB will result in	no volume level	change,	relative to the	source
	   volume, during audio	reproduction. Valid values are whole numbers
	   in the range	-31 to -1, with	-31 being the default.

       -dsur_mode mode
	   Dolby Surround Mode.	Specifies whether the stereo signal uses Dolby
	   Surround (Pro Logic). This field will only be written to the
	   bitstream if	the audio stream is stereo. Using this option does NOT
	   mean	the encoder will actually apply	Dolby Surround processing.

	   0
	   notindicated
	       Not Indicated (default)

	   1
	   off Not Dolby Surround Encoded

	   2
	   on  Dolby Surround Encoded

       -original boolean
	   Original Bit	Stream Indicator. Specifies whether this audio is from
	   the original	source and not a copy.

	   0
	   off Not Original Source

	   1
	   on  Original	Source (default)

       Extended	Bitstream Information

       The extended bitstream options are part of the Alternate	Bit Stream
       Syntax as specified in Annex D of the A/52:2010 standard. It is grouped
       into 2 parts.  If any one parameter in a	group is specified, all	values
       in that group will be written to	the bitstream.	Default	values are
       used for	those that are written but have	not been specified.  If	the
       mixing levels are written, the decoder will use these values instead of
       the ones	specified in the "center_mixlev" and "surround_mixlev" options
       if it supports the Alternate Bit	Stream Syntax.

       Extended	Bitstream Information -	Part 1

       -dmix_mode mode
	   Preferred Stereo Downmix Mode. Allows the user to select either
	   Lt/Rt (Dolby	Surround) or Lo/Ro (normal stereo) as the preferred
	   stereo downmix mode.

	   0
	   notindicated
	       Not Indicated (default)

	   1
	   ltrt
	       Lt/Rt Downmix Preferred

	   2
	   loro
	       Lo/Ro Downmix Preferred

       -ltrt_cmixlev level
	   Lt/Rt Center	Mix Level. The amount of gain the decoder should apply
	   to the center channel when downmixing to stereo in Lt/Rt mode.

	   1.414
	       Apply +3dB gain

	   1.189
	       Apply +1.5dB gain

	   1.000
	       Apply 0dB gain

	   0.841
	       Apply -1.5dB gain

	   0.707
	       Apply -3.0dB gain

	   0.595
	       Apply -4.5dB gain (default)

	   0.500
	       Apply -6.0dB gain

	   0.000
	       Silence Center Channel

       -ltrt_surmixlev level
	   Lt/Rt Surround Mix Level. The amount	of gain	the decoder should
	   apply to the	surround channel(s) when downmixing to stereo in Lt/Rt
	   mode.

	   0.841
	       Apply -1.5dB gain

	   0.707
	       Apply -3.0dB gain

	   0.595
	       Apply -4.5dB gain

	   0.500
	       Apply -6.0dB gain (default)

	   0.000
	       Silence Surround	Channel(s)

       -loro_cmixlev level
	   Lo/Ro Center	Mix Level. The amount of gain the decoder should apply
	   to the center channel when downmixing to stereo in Lo/Ro mode.

	   1.414
	       Apply +3dB gain

	   1.189
	       Apply +1.5dB gain

	   1.000
	       Apply 0dB gain

	   0.841
	       Apply -1.5dB gain

	   0.707
	       Apply -3.0dB gain

	   0.595
	       Apply -4.5dB gain (default)

	   0.500
	       Apply -6.0dB gain

	   0.000
	       Silence Center Channel

       -loro_surmixlev level
	   Lo/Ro Surround Mix Level. The amount	of gain	the decoder should
	   apply to the	surround channel(s) when downmixing to stereo in Lo/Ro
	   mode.

	   0.841
	       Apply -1.5dB gain

	   0.707
	       Apply -3.0dB gain

	   0.595
	       Apply -4.5dB gain

	   0.500
	       Apply -6.0dB gain (default)

	   0.000
	       Silence Surround	Channel(s)

       Extended	Bitstream Information -	Part 2

       -dsurex_mode mode
	   Dolby Surround EX Mode. Indicates whether the stream	uses Dolby
	   Surround EX (7.1 matrixed to	5.1). Using this option	does NOT mean
	   the encoder will actually apply Dolby Surround EX processing.

	   0
	   notindicated
	       Not Indicated (default)

	   1
	   on  Dolby Surround EX Off

	   2
	   off Dolby Surround EX On

       -dheadphone_mode	mode
	   Dolby Headphone Mode. Indicates whether the stream uses Dolby
	   Headphone encoding (multi-channel matrixed to 2.0 for use with
	   headphones).	Using this option does NOT mean	the encoder will
	   actually apply Dolby	Headphone processing.

	   0
	   notindicated
	       Not Indicated (default)

	   1
	   on  Dolby Headphone Off

	   2
	   off Dolby Headphone On

       -ad_conv_type type
	   A/D Converter Type. Indicates whether the audio has passed through
	   HDCD	A/D conversion.

	   0
	   standard
	       Standard	A/D Converter (default)

	   1
	   hdcd
	       HDCD A/D	Converter

       Other AC-3 Encoding Options

       -stereo_rematrixing boolean
	   Stereo Rematrixing. Enables/Disables	use of rematrixing for stereo
	   input. This is an optional AC-3 feature that	increases quality by
	   selectively encoding	the left/right channels	as mid/side. This
	   option is enabled by	default, and it	is highly recommended that it
	   be left as enabled except for testing purposes.

       cutoff frequency
	   Set lowpass cutoff frequency. If unspecified, the encoder selects a
	   default determined by various other encoding	parameters.

       Floating-Point-Only AC-3	Encoding Options

       These options are only valid for	the floating-point encoder and do not
       exist for the fixed-point encoder due to	the corresponding features not
       being implemented in fixed-point.

       -channel_coupling boolean
	   Enables/Disables use	of channel coupling, which is an optional AC-3
	   feature that	increases quality by combining high frequency
	   information from multiple channels into a single channel. The per-
	   channel high	frequency information is sent with less	accuracy in
	   both	the frequency and time domains.	This allows more bits to be
	   used	for lower frequencies while preserving enough information to
	   reconstruct the high	frequencies. This option is enabled by default
	   for the floating-point encoder and should generally be left as
	   enabled except for testing purposes or to increase encoding speed.

	   -1
	   auto
	       Selected	by Encoder (default)

	   0
	   off Disable Channel Coupling

	   1
	   on  Enable Channel Coupling

       -cpl_start_band number
	   Coupling Start Band.	Sets the channel coupling start	band, from 1
	   to 15. If a value higher than the bandwidth is used,	it will	be
	   reduced to 1	less than the coupling end band. If auto is used, the
	   start band will be determined by the	encoder	based on the bit rate,
	   sample rate,	and channel layout. This option	has no effect if
	   channel coupling is disabled.

	   -1
	   auto
	       Selected	by Encoder (default)

   flac
       FLAC (Free Lossless Audio Codec)	Encoder

       Options

       The following options are supported by FFmpeg's flac encoder.

       compression_level
	   Sets	the compression	level, which chooses defaults for many other
	   options if they are not set explicitly. Valid values	are from 0 to
	   12, 5 is the	default.

       frame_size
	   Sets	the size of the	frames in samples per channel.

       lpc_coeff_precision
	   Sets	the LPC	coefficient precision, valid values are	from 1 to 15,
	   15 is the default.

       lpc_type
	   Sets	the first stage	LPC algorithm

	   none
	       LPC is not used

	   fixed
	       fixed LPC coefficients

	   levinson
	   cholesky
       lpc_passes
	   Number of passes to use for Cholesky	factorization during LPC
	   analysis

       min_partition_order
	   The minimum partition order

       max_partition_order
	   The maximum partition order

       prediction_order_method
	   estimation
	   2level
	   4level
	   8level
	   search
	       Bruteforce search

	   log
       ch_mode
	   Channel mode

	   auto
	       The mode	is chosen automatically	for each frame

	   indep
	       Chanels are independently coded

	   left_side
	   right_side
	   mid_side
       exact_rice_parameters
	   Chooses if rice parameters are calculated exactly or	approximately.
	   if set to 1 then they are chosen exactly, which slows the code down
	   slightly and	improves compression slightly.

       multi_dim_quant
	   Multi Dimensional Quantization. If set to 1 then a 2nd stage	LPC
	   algorithm is	applied	after the first	stage to finetune the
	   coefficients. This is quite slow and	slightly improves compression.

   opus
       Opus encoder.

       This is a native	FFmpeg encoder for the Opus format. Currently its in
       development and only implements the CELT	part of	the codec. Its quality
       is usually worse	and at best is equal to	the libopus encoder.

       Options

       b   Set bit rate	in bits/s. If unspecified it uses the number of
	   channels and	the layout to make a good guess.

       opus_delay
	   Sets	the maximum delay in milliseconds. Lower delays	than 20ms will
	   very	quickly	decrease quality.

   libfdk_aac
       libfdk-aac AAC (Advanced	Audio Coding) encoder wrapper.

       The libfdk-aac library is based on the Fraunhofer FDK AAC code from the
       Android project.

       Requires	the presence of	the libfdk-aac headers and library during
       configuration. You need to explicitly configure the build with
       "--enable-libfdk-aac". The library is also incompatible with GPL, so if
       you allow the use of GPL, you should configure with "--enable-gpl
       --enable-nonfree	--enable-libfdk-aac".

       This encoder is considered to produce output on par or worse at 128kbps
       to the the native FFmpeg	AAC encoder but	can often produce better
       sounding	audio at identical or lower bitrates and has support for the
       AAC-HE profiles.

       VBR encoding, enabled through the vbr or	flags +qscale options, is
       experimental and	only works with	some combinations of parameters.

       Support for encoding 7.1	audio is only available	with libfdk-aac	0.1.3
       or higher.

       For more	information see	the fdk-aac project at
       <http://sourceforge.net/p/opencore-amr/fdk-aac/>.

       Options

       The following options are mapped	on the shared FFmpeg codec options.

       b   Set bit rate	in bits/s. If the bitrate is not explicitly specified,
	   it is automatically set to a	suitable value depending on the
	   selected profile.

	   In case VBR mode is enabled the option is ignored.

       ar  Set audio sampling rate (in Hz).

       channels
	   Set the number of audio channels.

       flags +qscale
	   Enable fixed	quality, VBR (Variable Bit Rate) mode.	Note that VBR
	   is implicitly enabled when the vbr value is positive.

       cutoff
	   Set cutoff frequency. If not	specified (or explicitly set to	0) it
	   will	use a value automatically computed by the library. Default
	   value is 0.

       profile
	   Set audio profile.

	   The following profiles are recognized:

	   aac_low
	       Low Complexity AAC (LC)

	   aac_he
	       High Efficiency AAC (HE-AAC)

	   aac_he_v2
	       High Efficiency AAC version 2 (HE-AACv2)

	   aac_ld
	       Low Delay AAC (LD)

	   aac_eld
	       Enhanced	Low Delay AAC (ELD)

	   If not specified it is set to aac_low.

       The following are private options of the	libfdk_aac encoder.

       afterburner
	   Enable afterburner feature if set to	1, disabled if set to 0. This
	   improves the	quality	but also the required processing power.

	   Default value is 1.

       eld_sbr
	   Enable SBR (Spectral	Band Replication) for ELD if set to 1,
	   disabled if set to 0.

	   Default value is 0.

       signaling
	   Set SBR/PS signaling	style.

	   It can assume one of	the following values:

	   default
	       choose signaling	implicitly (explicit hierarchical by default,
	       implicit	if global header is disabled)

	   implicit
	       implicit	backwards compatible signaling

	   explicit_sbr
	       explicit	SBR, implicit PS signaling

	   explicit_hierarchical
	       explicit	hierarchical signaling

	   Default value is default.

       latm
	   Output LATM/LOAS encapsulated data if set to	1, disabled if set to
	   0.

	   Default value is 0.

       header_period
	   Set StreamMuxConfig and PCE repetition period (in frames) for
	   sending in-band configuration buffers within	LATM/LOAS transport
	   layer.

	   Must	be a 16-bits non-negative integer.

	   Default value is 0.

       vbr Set VBR mode, from 1	to 5. 1	is lowest quality (though still	pretty
	   good) and 5 is highest quality. A value of 0	will disable VBR, and
	   CBR (Constant Bit Rate) is enabled.

	   Currently only the aac_low profile supports VBR encoding.

	   VBR modes 1-5 correspond to roughly the following average bit
	   rates:

	   1   32 kbps/channel

	   2   40 kbps/channel

	   3   48-56 kbps/channel

	   4   64 kbps/channel

	   5   about 80-96 kbps/channel

	   Default value is 0.

       Examples

       o   Use ffmpeg to convert an audio file to VBR AAC in an	M4A (MP4)
	   container:

		   ffmpeg -i input.wav -codec:a	libfdk_aac -vbr	3 output.m4a

       o   Use ffmpeg to convert an audio file to CBR 64k kbps AAC, using the
	   High-Efficiency AAC profile:

		   ffmpeg -i input.wav -c:a libfdk_aac -profile:a aac_he -b:a 64k output.m4a

   libmp3lame
       LAME (Lame Ain't	an MP3 Encoder)	MP3 encoder wrapper.

       Requires	the presence of	the libmp3lame headers and library during
       configuration. You need to explicitly configure the build with
       "--enable-libmp3lame".

       See libshine for	a fixed-point MP3 encoder, although with a lower
       quality.

       Options

       The following options are supported by the libmp3lame wrapper. The
       lame-equivalent of the options are listed in parentheses.

       b (-b)
	   Set bitrate expressed in bits/s for CBR or ABR. LAME	"bitrate" is
	   expressed in	kilobits/s.

       q (-V)
	   Set constant	quality	setting	for VBR. This option is	valid only
	   using the ffmpeg command-line tool. For library interface users,
	   use global_quality.

       compression_level (-q)
	   Set algorithm quality. Valid	arguments are integers in the 0-9
	   range, with 0 meaning highest quality but slowest, and 9 meaning
	   fastest while producing the worst quality.

       cutoff (--lowpass)
	   Set lowpass cutoff frequency. If unspecified, the encoder
	   dynamically adjusts the cutoff.

       reservoir
	   Enable use of bit reservoir when set	to 1. Default value is 1. LAME
	   has this enabled by default,	but can	be overridden by use --nores
	   option.

       joint_stereo (-m	j)
	   Enable the encoder to use (on a frame by frame basis) either	L/R
	   stereo or mid/side stereo. Default value is 1.

       abr (--abr)
	   Enable the encoder to use ABR when set to 1.	The lame --abr sets
	   the target bitrate, while this options only tells FFmpeg to use ABR
	   still relies	on b to	set bitrate.

   libopencore-amrnb
       OpenCORE	Adaptive Multi-Rate Narrowband encoder.

       Requires	the presence of	the libopencore-amrnb headers and library
       during configuration. You need to explicitly configure the build	with
       "--enable-libopencore-amrnb --enable-version3".

       This is a mono-only encoder. Officially it only supports	8000Hz sample
       rate, but you can override it by	setting	strict to unofficial or	lower.

       Options

       b   Set bitrate in bits per second. Only	the following bitrates are
	   supported, otherwise	libavcodec will	round to the nearest valid
	   bitrate.

	   4750
	   5150
	   5900
	   6700
	   7400
	   7950
	   10200
	   12200
       dtx Allow discontinuous transmission (generate comfort noise) when set
	   to 1. The default value is 0	(disabled).

   libopus
       libopus Opus Interactive	Audio Codec encoder wrapper.

       Requires	the presence of	the libopus headers and	library	during
       configuration. You need to explicitly configure the build with
       "--enable-libopus".

       Option Mapping

       Most libopus options are	modelled after the opusenc utility from	opus-
       tools. The following is an option mapping chart describing options
       supported by the	libopus	wrapper, and their opusenc-equivalent in
       parentheses.

       b (bitrate)
	   Set the bit rate in bits/s.	FFmpeg's b option is expressed in
	   bits/s, while opusenc's bitrate in kilobits/s.

       vbr (vbr, hard-cbr, and cvbr)
	   Set VBR mode. The FFmpeg vbr	option has the following valid
	   arguments, with the opusenc equivalent options in parentheses:

	   off (hard-cbr)
	       Use constant bit	rate encoding.

	   on (vbr)
	       Use variable bit	rate encoding (the default).

	   constrained (cvbr)
	       Use constrained variable	bit rate encoding.

       compression_level (comp)
	   Set encoding	algorithm complexity. Valid options are	integers in
	   the 0-10 range. 0 gives the fastest encodes but lower quality,
	   while 10 gives the highest quality but slowest encoding. The
	   default is 10.

       frame_duration (framesize)
	   Set maximum frame size, or duration of a frame in milliseconds. The
	   argument must be exactly the	following: 2.5,	5, 10, 20, 40, 60.
	   Smaller frame sizes achieve lower latency but less quality at a
	   given bitrate.  Sizes greater than 20ms are only interesting	at
	   fairly low bitrates.	 The default is	20ms.

       packet_loss (expect-loss)
	   Set expected	packet loss percentage.	The default is 0.

       application (N.A.)
	   Set intended	application type. Valid	options	are listed below:

	   voip
	       Favor improved speech intelligibility.

	   audio
	       Favor faithfulness to the input (the default).

	   lowdelay
	       Restrict	to only	the lowest delay modes.

       cutoff (N.A.)
	   Set cutoff bandwidth	in Hz. The argument must be exactly one	of the
	   following: 4000, 6000, 8000,	12000, or 20000, corresponding to
	   narrowband, mediumband, wideband, super wideband, and fullband
	   respectively. The default is	0 (cutoff disabled).

       mapping_family (mapping_family)
	   Set channel mapping family to be used by the	encoder. The default
	   value of -1 uses mapping family 0 for mono and stereo inputs, and
	   mapping family 1 otherwise. The default also	disables the surround
	   masking and LFE bandwidth optimzations in libopus, and requires
	   that	the input contains 8 channels or fewer.

	   Other values	include	0 for mono and stereo, 1 for surround sound
	   with	masking	and LFE	bandwidth optimizations, and 255 for
	   independent streams with an unspecified channel layout.

   libshine
       Shine Fixed-Point MP3 encoder wrapper.

       Shine is	a fixed-point MP3 encoder. It has a far	better performance on
       platforms without an FPU, e.g. armel CPUs, and some phones and tablets.
       However,	as it is more targeted on performance than quality, it is not
       on par with LAME	and other production-grade encoders quality-wise.
       Also, according to the project's	homepage, this encoder may not be free
       of bugs as the code was written a long time ago and the project was
       dead for	at least 5 years.

       This encoder only supports stereo and mono input. This is also CBR-
       only.

       The original project (last updated in early 2007) is at
       <http://sourceforge.net/projects/libshine-fxp/>.	We only	support	the
       updated fork by the Savonet/Liquidsoap project at
       <https://github.com/savonet/shine>.

       Requires	the presence of	the libshine headers and library during
       configuration. You need to explicitly configure the build with
       "--enable-libshine".

       See also	libmp3lame.

       Options

       The following options are supported by the libshine wrapper. The
       shineenc-equivalent of the options are listed in	parentheses.

       b (-b)
	   Set bitrate expressed in bits/s for CBR. shineenc -b	option is
	   expressed in	kilobits/s.

   libtwolame
       TwoLAME MP2 encoder wrapper.

       Requires	the presence of	the libtwolame headers and library during
       configuration. You need to explicitly configure the build with
       "--enable-libtwolame".

       Options

       The following options are supported by the libtwolame wrapper. The
       twolame-equivalent options follow the FFmpeg ones and are in
       parentheses.

       b (-b)
	   Set bitrate expressed in bits/s for CBR. twolame b option is
	   expressed in	kilobits/s. Default value is 128k.

       q (-V)
	   Set quality for experimental	VBR support. Maximum value range is
	   from	-50 to 50, useful range	is from	-10 to 10. The higher the
	   value, the better the quality. This option is valid only using the
	   ffmpeg command-line tool. For library interface users, use
	   global_quality.

       mode (--mode)
	   Set the mode	of the resulting audio.	Possible values:

	   auto
	       Choose mode automatically based on the input. This is the
	       default.

	   stereo
	       Stereo

	   joint_stereo
	       Joint stereo

	   dual_channel
	       Dual channel

	   mono
	       Mono

       psymodel	(--psyc-mode)
	   Set psychoacoustic model to use in encoding.	The argument must be
	   an integer between -1 and 4,	inclusive. The higher the value, the
	   better the quality. The default value is 3.

       energy_levels (--energy)
	   Enable energy levels	extensions when	set to 1. The default value is
	   0 (disabled).

       error_protection	(--protect)
	   Enable CRC error protection when set	to 1. The default value	is 0
	   (disabled).

       copyright (--copyright)
	   Set MPEG audio copyright flag when set to 1.	The default value is 0
	   (disabled).

       original	(--original)
	   Set MPEG audio original flag	when set to 1. The default value is 0
	   (disabled).

   libvo-amrwbenc
       VisualOn	Adaptive Multi-Rate Wideband encoder.

       Requires	the presence of	the libvo-amrwbenc headers and library during
       configuration. You need to explicitly configure the build with
       "--enable-libvo-amrwbenc	--enable-version3".

       This is a mono-only encoder. Officially it only supports	16000Hz	sample
       rate, but you can override it by	setting	strict to unofficial or	lower.

       Options

       b   Set bitrate in bits/s. Only the following bitrates are supported,
	   otherwise libavcodec	will round to the nearest valid	bitrate.

	   6600
	   8850
	   12650
	   14250
	   15850
	   18250
	   19850
	   23050
	   23850
       dtx Allow discontinuous transmission (generate comfort noise) when set
	   to 1. The default value is 0	(disabled).

   libvorbis
       libvorbis encoder wrapper.

       Requires	the presence of	the libvorbisenc headers and library during
       configuration. You need to explicitly configure the build with
       "--enable-libvorbis".

       Options

       The following options are supported by the libvorbis wrapper. The
       oggenc-equivalent of the	options	are listed in parentheses.

       To get a	more accurate and extensive documentation of the libvorbis
       options,	consult	the libvorbisenc's and oggenc's	documentations.	 See
       <http://xiph.org/vorbis/>, <http://wiki.xiph.org/Vorbis-tools>, and
       oggenc(1).

       b (-b)
	   Set bitrate expressed in bits/s for ABR. oggenc -b is expressed in
	   kilobits/s.

       q (-q)
	   Set constant	quality	setting	for VBR. The value should be a float
	   number in the range of -1.0 to 10.0.	The higher the value, the
	   better the quality. The default value is 3.0.

	   This	option is valid	only using the ffmpeg command-line tool.  For
	   library interface users, use	global_quality.

       cutoff (--advanced-encode-option	lowpass_frequency=N)
	   Set cutoff bandwidth	in Hz, a value of 0 disables cutoff. oggenc's
	   related option is expressed in kHz. The default value is 0 (cutoff
	   disabled).

       minrate (-m)
	   Set minimum bitrate expressed in bits/s. oggenc -m is expressed in
	   kilobits/s.

       maxrate (-M)
	   Set maximum bitrate expressed in bits/s. oggenc -M is expressed in
	   kilobits/s. This only has effect on ABR mode.

       iblock (--advanced-encode-option	impulse_noisetune=N)
	   Set noise floor bias	for impulse blocks. The	value is a float
	   number from -15.0 to	0.0. A negative	bias instructs the encoder to
	   pay special attention to the	crispness of transients	in the encoded
	   audio. The tradeoff for better transient response is	a higher
	   bitrate.

   libwavpack
       A wrapper providing WavPack encoding through libwavpack.

       Only lossless mode using	32-bit integer samples is supported currently.

       Requires	the presence of	the libwavpack headers and library during
       configuration. You need to explicitly configure the build with
       "--enable-libwavpack".

       Note that a libavcodec-native encoder for the WavPack codec exists so
       users can encode	audios with this codec without using this encoder. See
       wavpackenc.

       Options

       wavpack command line utility's corresponding options are	listed in
       parentheses, if any.

       frame_size (--blocksize)
	   Default is 32768.

       compression_level
	   Set speed vs. compression tradeoff. Acceptable arguments are	listed
	   below:

	   0 (-f)
	       Fast mode.

	   1   Normal (default)	settings.

	   2 (-h)
	       High quality.

	   3 (-hh)
	       Very high quality.

	   4-8 (-hh -xEXTRAPROC)
	       Same as 3, but with extra processing enabled.

	       4 is the	same as	-x2 and	8 is the same as -x6.

   mjpeg
       Motion JPEG encoder.

       Options

       huffman
	   Set the huffman encoding strategy. Possible values:

	   default
	       Use the default huffman tables. This is the default strategy.

	   optimal
	       Compute and use optimal huffman tables.

   wavpack
       WavPack lossless	audio encoder.

       This is a libavcodec-native WavPack encoder. There is also an encoder
       based on	libwavpack, but	there is virtually no reason to	use that
       encoder.

       See also	libwavpack.

       Options

       The equivalent options for wavpack command line utility are listed in
       parentheses.

       Shared options

       The following shared options are	effective for this encoder. Only
       special notes about this	particular encoder will	be documented here.
       For the general meaning of the options, see the Codec Options chapter.

       frame_size (--blocksize)
	   For this encoder, the range for this	option is between 128 and
	   131072. Default is automatically decided based on sample rate and
	   number of channel.

	   For the complete formula of calculating default, see
	   libavcodec/wavpackenc.c.

       compression_level (-f, -h, -hh, and -x)
	   This	option's syntax	is consistent with libwavpack's.

       Private options

       joint_stereo (-j)
	   Set whether to enable joint stereo. Valid values are:

	   on (1)
	       Force mid/side audio encoding.

	   off (0)
	       Force left/right	audio encoding.

	   auto
	       Let the encoder decide automatically.

       optimize_mono
	   Set whether to enable optimization for mono.	This option is only
	   effective for non-mono streams. Available values:

	   on  enabled

	   off disabled

VIDEO ENCODERS
       A description of	some of	the currently available	video encoders
       follows.

   Hap
       Vidvox Hap video	encoder.

       Options

       format integer
	   Specifies the Hap format to encode.

	   hap
	   hap_alpha
	   hap_q

	   Default value is hap.

       chunks integer
	   Specifies the number	of chunks to split frames into,	between	1 and
	   64. This permits multithreaded decoding of large frames,
	   potentially at the cost of data-rate. The encoder may modify	this
	   value to divide frames evenly.

	   Default value is 1.

       compressor integer
	   Specifies the second-stage compressor to use. If set	to none,
	   chunks will be limited to 1,	as chunked uncompressed	frames offer
	   no benefit.

	   none
	   snappy

	   Default value is snappy.

   jpeg2000
       The native jpeg 2000 encoder is lossy by	default, the "-q:v" option can
       be used to set the encoding quality. Lossless encoding can be selected
       with "-pred 1".

       Options

       format
	   Can be set to either	"j2k" or "jp2" (the default) that makes	it
	   possible to store non-rgb pix_fmts.

   libkvazaar
       Kvazaar H.265/HEVC encoder.

       Requires	the presence of	the libkvazaar headers and library during
       configuration. You need to explicitly configure the build with
       --enable-libkvazaar.

       Options

       b   Set target video bitrate in bit/s and enable	rate control.

       kvazaar-params
	   Set kvazaar parameters as a list of name=value pairs	separated by
	   commas (,). See kvazaar documentation for a list of options.

   libopenh264
       Cisco libopenh264 H.264/MPEG-4 AVC encoder wrapper.

       This encoder requires the presence of the libopenh264 headers and
       library during configuration. You need to explicitly configure the
       build with "--enable-libopenh264". The library is detected using	pkg-
       config.

       For more	information about the library see <http://www.openh264.org>.

       Options

       The following FFmpeg global options affect the configurations of	the
       libopenh264 encoder.

       b   Set the bitrate (as a number	of bits	per second).

       g   Set the GOP size.

       maxrate
	   Set the max bitrate (as a number of bits per	second).

       flags +global_header
	   Set global header in	the bitstream.

       slices
	   Set the number of slices, used in parallelized encoding. Default
	   value is 0. This is only used when slice_mode is set	to fixed.

       slice_mode
	   Set slice mode. Can assume one of the following possible values:

	   fixed
	       a fixed number of slices

	   rowmb
	       one slice per row of macroblocks

	   auto
	       automatic number	of slices according to number of threads

	   dyn dynamic slicing

	   Default value is auto.

       loopfilter
	   Enable loop filter, if set to 1 (automatically enabled). To disable
	   set a value of 0.

       profile
	   Set profile restrictions. If	set to the value of main enable	CABAC
	   (set	the "SEncParamExt.iEntropyCodingModeFlag" flag to 1).

       max_nal_size
	   Set maximum NAL size	in bytes.

       allow_skip_frames
	   Allow skipping frames to hit	the target bitrate if set to 1.

   libtheora
       libtheora Theora	encoder	wrapper.

       Requires	the presence of	the libtheora headers and library during
       configuration. You need to explicitly configure the build with
       "--enable-libtheora".

       For more	information about the libtheora	project	see
       <http://www.theora.org/>.

       Options

       The following global options are	mapped to internal libtheora options
       which affect the	quality	and the	bitrate	of the encoded stream.

       b   Set the video bitrate in bit/s for CBR (Constant Bit	Rate) mode.
	   In case VBR (Variable Bit Rate) mode	is enabled this	option is
	   ignored.

       flags
	   Used	to enable constant quality mode	(VBR) encoding through the
	   qscale flag,	and to enable the "pass1" and "pass2" modes.

       g   Set the GOP size.

       global_quality
	   Set the global quality as an	integer	in lambda units.

	   Only	relevant when VBR mode is enabled with "flags +qscale".	The
	   value is converted to QP units by dividing it by "FF_QP2LAMBDA",
	   clipped in the [0 - 10] range, and then multiplied by 6.3 to	get a
	   value in the	native libtheora range [0-63]. A higher	value
	   corresponds to a higher quality.

       q   Enable VBR mode when	set to a non-negative value, and set constant
	   quality value as a double floating point value in QP	units.

	   The value is	clipped	in the [0-10] range, and then multiplied by
	   6.3 to get a	value in the native libtheora range [0-63].

	   This	option is valid	only using the ffmpeg command-line tool. For
	   library interface users, use	global_quality.

       Examples

       o   Set maximum constant	quality	(VBR) encoding with ffmpeg:

		   ffmpeg -i INPUT -codec:v libtheora -q:v 10 OUTPUT.ogg

       o   Use ffmpeg to convert a CBR 1000 kbps Theora	video stream:

		   ffmpeg -i INPUT -codec:v libtheora -b:v 1000k OUTPUT.ogg

   libvpx
       VP8/VP9 format supported	through	libvpx.

       Requires	the presence of	the libvpx headers and library during
       configuration.  You need	to explicitly configure	the build with
       "--enable-libvpx".

       Options

       The following options are supported by the libvpx wrapper. The
       vpxenc-equivalent options or values are listed in parentheses for easy
       migration.

       To reduce the duplication of documentation, only	the private options
       and some	others requiring special attention are documented here.	For
       the documentation of the	undocumented generic options, see the Codec
       Options chapter.

       To get more documentation of the	libvpx options,	invoke the command
       ffmpeg -h encoder=libvpx, ffmpeg	-h encoder=libvpx-vp9 or vpxenc
       --help. Further information is available	in the libvpx API
       documentation.

       b (target-bitrate)
	   Set bitrate in bits/s. Note that FFmpeg's b option is expressed in
	   bits/s, while vpxenc's target-bitrate is in kilobits/s.

       g (kf-max-dist)
       keyint_min (kf-min-dist)
       qmin (min-q)
       qmax (max-q)
       bufsize (buf-sz,	buf-optimal-sz)
	   Set ratecontrol buffer size (in bits). Note vpxenc's	options	are
	   specified in	milliseconds, the libvpx wrapper converts this value
	   as follows: "buf-sz = bufsize * 1000	/ bitrate", "buf-optimal-sz =
	   bufsize * 1000 / bitrate * 5	/ 6".

       rc_init_occupancy (buf-initial-sz)
	   Set number of bits which should be loaded into the rc buffer	before
	   decoding starts. Note vpxenc's option is specified in milliseconds,
	   the libvpx wrapper converts this value as follows:
	   "rc_init_occupancy *	1000 / bitrate".

       undershoot-pct
	   Set datarate	undershoot (min) percentage of the target bitrate.

       overshoot-pct
	   Set datarate	overshoot (max)	percentage of the target bitrate.

       skip_threshold (drop-frame)
       qcomp (bias-pct)
       maxrate (maxsection-pct)
	   Set GOP max bitrate in bits/s. Note vpxenc's	option is specified as
	   a percentage	of the target bitrate, the libvpx wrapper converts
	   this	value as follows: "(maxrate * 100 / bitrate)".

       minrate (minsection-pct)
	   Set GOP min bitrate in bits/s. Note vpxenc's	option is specified as
	   a percentage	of the target bitrate, the libvpx wrapper converts
	   this	value as follows: "(minrate * 100 / bitrate)".

       minrate,	maxrate, b end-usage=cbr
	   "(minrate ==	maxrate	== bitrate)".

       crf (end-usage=cq, cq-level)
       tune (tune)
	   psnr	(psnr)
	   ssim	(ssim)
       quality,	deadline (deadline)
	   best
	       Use best	quality	deadline. Poorly named and quite slow, this
	       option should be	avoided	as it may give worse quality output
	       than good.

	   good
	       Use good	quality	deadline. This is a good trade-off between
	       speed and quality when used with	the cpu-used option.

	   realtime
	       Use realtime quality deadline.

       speed, cpu-used (cpu-used)
	   Set quality/speed ratio modifier. Higher values speed up the	encode
	   at the cost of quality.

       nr (noise-sensitivity)
       static-thresh
	   Set a change	threshold on blocks below which	they will be skipped
	   by the encoder.

       slices (token-parts)
	   Note	that FFmpeg's slices option gives the total number of
	   partitions, while vpxenc's token-parts is given as
	   "log2(partitions)".

       max-intra-rate
	   Set maximum I-frame bitrate as a percentage of the target bitrate.
	   A value of 0	means unlimited.

       force_key_frames
	   "VPX_EFLAG_FORCE_KF"

       Alternate reference frame related
	   auto-alt-ref
	       Enable use of alternate reference frames	(2-pass	only).

	   arnr-max-frames
	       Set altref noise	reduction max frame count.

	   arnr-type
	       Set altref noise	reduction filter type: backward, forward,
	       centered.

	   arnr-strength
	       Set altref noise	reduction filter strength.

	   rc-lookahead, lag-in-frames (lag-in-frames)
	       Set number of frames to look ahead for frametype	and
	       ratecontrol.

       error-resilient
	   Enable error	resiliency features.

       VP9-specific options
	   lossless
	       Enable lossless mode.

	   tile-columns
	       Set number of tile columns to use. Note this is given as
	       "log2(tile_columns)". For example, 8 tile columns would be
	       requested by setting the	tile-columns option to 3.

	   tile-rows
	       Set number of tile rows to use. Note this is given as
	       "log2(tile_rows)".  For example,	4 tile rows would be requested
	       by setting the tile-rows	option to 2.

	   frame-parallel
	       Enable frame parallel decodability features.

	   aq-mode
	       Set adaptive quantization mode (0: off (default), 1: variance
	       2: complexity, 3: cyclic	refresh).

	   colorspace color-space
	       Set input color space. The VP9 bitstream	supports signaling the
	       following colorspaces:

	       rgb sRGB
	       bt709 bt709
	       unspecified unknown
	       bt470bg bt601
	       smpte170m smpte170
	       smpte240m smpte240
	       bt2020_ncl bt2020

       For more	information about libvpx see: <http://www.webmproject.org/>

   libwebp
       libwebp WebP Image encoder wrapper

       libwebp is Google's official encoder for	WebP images. It	can encode in
       either lossy or lossless	mode. Lossy images are essentially a wrapper
       around a	VP8 frame. Lossless images are a separate codec	developed by
       Google.

       Pixel Format

       Currently, libwebp only supports	YUV420 for lossy and RGB for lossless
       due to limitations of the format	and libwebp. Alpha is supported	for
       either mode.  Because of	API limitations, if RGB	is passed in when
       encoding	lossy or YUV is	passed in for encoding lossless, the pixel
       format will automatically be converted using functions from libwebp.
       This is not ideal and is	done only for convenience.

       Options

       -lossless boolean
	   Enables/Disables use	of lossless mode. Default is 0.

       -compression_level integer
	   For lossy, this is a	quality/speed tradeoff.	Higher values give
	   better quality for a	given size at the cost of increased encoding
	   time. For lossless, this is a size/speed tradeoff. Higher values
	   give	smaller	size at	the cost of increased encoding time. More
	   specifically, it controls the number	of extra algorithms and
	   compression tools used, and varies the combination of these tools.
	   This	maps to	the method option in libwebp. The valid	range is 0 to
	   6.  Default is 4.

       -qscale float
	   For lossy encoding, this controls image quality, 0 to 100. For
	   lossless encoding, this controls the	effort and time	spent at
	   compressing more. The default value is 75. Note that	for usage via
	   libavcodec, this option is called global_quality and	must be
	   multiplied by FF_QP2LAMBDA.

       -preset type
	   Configuration preset. This does some	automatic settings based on
	   the general type of the image.

	   none
	       Do not use a preset.

	   default
	       Use the encoder default.

	   picture
	       Digital picture,	like portrait, inner shot

	   photo
	       Outdoor photograph, with	natural	lighting

	   drawing
	       Hand or line drawing, with high-contrast	details

	   icon
	       Small-sized colorful images

	   text
	       Text-like

   libx264, libx264rgb
       x264 H.264/MPEG-4 AVC encoder wrapper.

       This encoder requires the presence of the libx264 headers and library
       during configuration. You need to explicitly configure the build	with
       "--enable-libx264".

       libx264 supports	an impressive number of	features, including 8x8	and
       4x4 adaptive spatial transform, adaptive	B-frame	placement, CAVLC/CABAC
       entropy coding, interlacing (MBAFF), lossless mode, psy optimizations
       for detail retention (adaptive quantization, psy-RD, psy-trellis).

       Many libx264 encoder options are	mapped to FFmpeg global	codec options,
       while unique encoder options are	provided through private options.
       Additionally the	x264opts and x264-params private options allows	one to
       pass a list of key=value	tuples as accepted by the libx264
       "x264_param_parse" function.

       The x264	project	website	is at
       <http://www.videolan.org/developers/x264.html>.

       The libx264rgb encoder is the same as libx264, except it	accepts	packed
       RGB pixel formats as input instead of YUV.

       Supported Pixel Formats

       x264 supports 8-	to 10-bit color	spaces.	The exact bit depth is
       controlled at x264's configure time. FFmpeg only	supports one bit depth
       in one particular build.	In other words,	it is not possible to build
       one FFmpeg with multiple	versions of x264 with different	bit depths.

       Options

       The following options are supported by the libx264 wrapper. The
       x264-equivalent options or values are listed in parentheses for easy
       migration.

       To reduce the duplication of documentation, only	the private options
       and some	others requiring special attention are documented here.	For
       the documentation of the	undocumented generic options, see the Codec
       Options chapter.

       To get a	more accurate and extensive documentation of the libx264
       options,	invoke the command x264	--full-help or consult the libx264
       documentation.

       b (bitrate)
	   Set bitrate in bits/s. Note that FFmpeg's b option is expressed in
	   bits/s, while x264's	bitrate	is in kilobits/s.

       bf (bframes)
       g (keyint)
       qmin (qpmin)
	   Minimum quantizer scale.

       qmax (qpmax)
	   Maximum quantizer scale.

       qdiff (qpstep)
	   Maximum difference between quantizer	scales.

       qblur (qblur)
	   Quantizer curve blur

       qcomp (qcomp)
	   Quantizer curve compression factor

       refs (ref)
	   Number of reference frames each P-frame can use. The	range is from
	   0-16.

       sc_threshold (scenecut)
	   Sets	the threshold for the scene change detection.

       trellis (trellis)
	   Performs Trellis quantization to increase efficiency. Enabled by
	   default.

       nr  (nr)
       me_range	(merange)
	   Maximum range of the	motion search in pixels.

       me_method (me)
	   Set motion estimation method. Possible values in the	decreasing
	   order of speed:

	   dia (dia)
	   epzs	(dia)
	       Diamond search with radius 1 (fastest). epzs is an alias	for
	       dia.

	   hex (hex)
	       Hexagonal search	with radius 2.

	   umh (umh)
	       Uneven multi-hexagon search.

	   esa (esa)
	       Exhaustive search.

	   tesa	(tesa)
	       Hadamard	exhaustive search (slowest).

       forced-idr
	   Normally, when forcing a I-frame type, the encoder can select any
	   type	of I-frame. This option	forces it to choose an IDR-frame.

       subq (subme)
	   Sub-pixel motion estimation method.

       b_strategy (b-adapt)
	   Adaptive B-frame placement decision algorithm. Use only on first-
	   pass.

       keyint_min (min-keyint)
	   Minimum GOP size.

       coder
	   Set entropy encoder.	Possible values:

	   ac  Enable CABAC.

	   vlc Enable CAVLC and	disable	CABAC. It generates the	same effect as
	       x264's --no-cabac option.

       cmp Set full pixel motion estimation comparison algorithm. Possible
	   values:

	   chroma
	       Enable chroma in	motion estimation.

	   sad Ignore chroma in	motion estimation. It generates	the same
	       effect as x264's	--no-chroma-me option.

       threads (threads)
	   Number of encoding threads.

       thread_type
	   Set multithreading technique. Possible values:

	   slice
	       Slice-based multithreading. It generates	the same effect	as
	       x264's --sliced-threads option.

	   frame
	       Frame-based multithreading.

       flags
	   Set encoding	flags. It can be used to disable closed	GOP and	enable
	   open	GOP by setting it to "-cgop". The result is similar to the
	   behavior of x264's --open-gop option.

       rc_init_occupancy (vbv-init)
       preset (preset)
	   Set the encoding preset.

       tune (tune)
	   Set tuning of the encoding params.

       profile (profile)
	   Set profile restrictions.

       fastfirstpass
	   Enable fast settings	when encoding first pass, when set to 1. When
	   set to 0, it	has the	same effect of x264's --slow-firstpass option.

       crf (crf)
	   Set the quality for constant	quality	mode.

       crf_max (crf-max)
	   In CRF mode,	prevents VBV from lowering quality beyond this point.

       qp (qp)
	   Set constant	quantization rate control method parameter.

       aq-mode (aq-mode)
	   Set AQ method. Possible values:

	   none	(0)
	       Disabled.

	   variance (1)
	       Variance	AQ (complexity mask).

	   autovariance	(2)
	       Auto-variance AQ	(experimental).

       aq-strength (aq-strength)
	   Set AQ strength, reduce blocking and	blurring in flat and textured
	   areas.

       psy Use psychovisual optimizations when set to 1. When set to 0,	it has
	   the same effect as x264's --no-psy option.

       psy-rd  (psy-rd)
	   Set strength	of psychovisual	optimization, in psy-rd:psy-trellis
	   format.

       rc-lookahead (rc-lookahead)
	   Set number of frames	to look	ahead for frametype and	ratecontrol.

       weightb
	   Enable weighted prediction for B-frames when	set to 1. When set to
	   0, it has the same effect as	x264's --no-weightb option.

       weightp (weightp)
	   Set weighted	prediction method for P-frames.	Possible values:

	   none	(0)
	       Disabled

	   simple (1)
	       Enable only weighted refs

	   smart (2)
	       Enable both weighted refs and duplicates

       ssim (ssim)
	   Enable calculation and printing SSIM	stats after the	encoding.

       intra-refresh (intra-refresh)
	   Enable the use of Periodic Intra Refresh instead of IDR frames when
	   set to 1.

       avcintra-class (class)
	   Configure the encoder to generate AVC-Intra.	 Valid values are
	   50,100 and 200

       bluray-compat (bluray-compat)
	   Configure the encoder to be compatible with the bluray standard.
	   It is a shorthand for setting "bluray-compat=1 force-cfr=1".

       b-bias (b-bias)
	   Set the influence on	how often B-frames are used.

       b-pyramid (b-pyramid)
	   Set method for keeping of some B-frames as references. Possible
	   values:

	   none	(none)
	       Disabled.

	   strict (strict)
	       Strictly	hierarchical pyramid.

	   normal (normal)
	       Non-strict (not Blu-ray compatible).

       mixed-refs
	   Enable the use of one reference per partition, as opposed to	one
	   reference per macroblock when set to	1. When	set to 0, it has the
	   same	effect as x264's --no-mixed-refs option.

       8x8dct
	   Enable adaptive spatial transform (high profile 8x8 transform) when
	   set to 1. When set to 0, it has the same effect as x264's
	   --no-8x8dct option.

       fast-pskip
	   Enable early	SKIP detection on P-frames when	set to 1. When set to
	   0, it has the same effect as	x264's --no-fast-pskip option.

       aud (aud)
	   Enable use of access	unit delimiters	when set to 1.

       mbtree
	   Enable use macroblock tree ratecontrol when set to 1. When set to
	   0, it has the same effect as	x264's --no-mbtree option.

       deblock (deblock)
	   Set loop filter parameters, in alpha:beta form.

       cplxblur	(cplxblur)
	   Set fluctuations reduction in QP (before curve compression).

       partitions (partitions)
	   Set partitions to consider as a comma-separated list	of. Possible
	   values in the list:

	   p8x8
	       8x8 P-frame partition.

	   p4x4
	       4x4 P-frame partition.

	   b8x8
	       4x4 B-frame partition.

	   i8x8
	       8x8 I-frame partition.

	   i4x4
	       4x4 I-frame partition.  (Enabling p4x4 requires p8x8 to be
	       enabled.	Enabling i8x8 requires adaptive	spatial	transform
	       (8x8dct option) to be enabled.)

	   none	(none)
	       Do not consider any partitions.

	   all (all)
	       Consider	every partition.

       direct-pred (direct)
	   Set direct MV prediction mode. Possible values:

	   none	(none)
	       Disable MV prediction.

	   spatial (spatial)
	       Enable spatial predicting.

	   temporal (temporal)
	       Enable temporal predicting.

	   auto	(auto)
	       Automatically decided.

       slice-max-size (slice-max-size)
	   Set the limit of the	size of	each slice in bytes. If	not specified
	   but RTP payload size	(ps) is	specified, that	is used.

       stats (stats)
	   Set the file	name for multi-pass stats.

       nal-hrd (nal-hrd)
	   Set signal HRD information (requires	vbv-bufsize to be set).
	   Possible values:

	   none	(none)
	       Disable HRD information signaling.

	   vbr (vbr)
	       Variable	bit rate.

	   cbr (cbr)
	       Constant	bit rate (not allowed in MP4 container).

       x264opts	(N.A.)
	   Set any x264	option,	see x264 --fullhelp for	a list.

	   Argument is a list of key=value couples separated by	":". In	filter
	   and psy-rd options that use ":" as a	separator themselves, use ","
	   instead. They accept	it as well since long ago but this is kept
	   undocumented	for some reason.

	   For example to specify libx264 encoding options with	ffmpeg:

		   ffmpeg -i foo.mpg -vcodec libx264 -x264opts keyint=123:min-keyint=20	-an out.mkv

       a53cc boolean
	   Import closed captions (which must be ATSC compatible format) into
	   output.  Only the mpeg2 and h264 decoders provide these. Default is
	   1 (on).

       x264-params (N.A.)
	   Override the	x264 configuration using a :-separated list of
	   key=value parameters.

	   This	option is functionally the same	as the x264opts, but is
	   duplicated for compatibility	with the Libav fork.

	   For example to specify libx264 encoding options with	ffmpeg:

		   ffmpeg -i INPUT -c:v	libx264	-x264-params level=30:bframes=0:weightp=0:\
		   cabac=0:ref=1:vbv-maxrate=768:vbv-bufsize=2000:analyse=all:me=umh:\
		   no-fast-pskip=1:subq=6:8x8dct=0:trellis=0 OUTPUT

       Encoding	ffpresets for common usages are	provided so they can be	used
       with the	general	presets	system (e.g. passing the pre option).

   libx265
       x265 H.265/HEVC encoder wrapper.

       This encoder requires the presence of the libx265 headers and library
       during configuration. You need to explicitly configure the build	with
       --enable-libx265.

       Options

       preset
	   Set the x265	preset.

       tune
	   Set the x265	tune parameter.

       forced-idr
	   Normally, when forcing a I-frame type, the encoder can select any
	   type	of I-frame. This option	forces it to choose an IDR-frame.

       x265-params
	   Set x265 options using a list of key=value couples separated	by
	   ":".	See x265 --help	for a list of options.

	   For example to specify libx265 encoding options with	-x265-params:

		   ffmpeg -i input -c:v	libx265	-x265-params crf=26:psy-rd=1 output.mp4

   libxvid
       Xvid MPEG-4 Part	2 encoder wrapper.

       This encoder requires the presence of the libxvidcore headers and
       library during configuration. You need to explicitly configure the
       build with "--enable-libxvid --enable-gpl".

       The native "mpeg4" encoder supports the MPEG-4 Part 2 format, so	users
       can encode to this format without this library.

       Options

       The following options are supported by the libxvid wrapper. Some	of the
       following options are listed but	are not	documented, and	correspond to
       shared codec options. See the Codec Options chapter for their
       documentation. The other	shared options which are not listed have no
       effect for the libxvid encoder.

       b
       g
       qmin
       qmax
       mpeg_quant
       threads
       bf
       b_qfactor
       b_qoffset
       flags
	   Set specific	encoding flags.	Possible values:

	   mv4 Use four	motion vector by macroblock.

	   aic Enable high quality AC prediction.

	   gray
	       Only encode grayscale.

	   gmc Enable the use of global	motion compensation (GMC).

	   qpel
	       Enable quarter-pixel motion compensation.

	   cgop
	       Enable closed GOP.

	   global_header
	       Place global headers in extradata instead of every keyframe.

       trellis
       me_method
	   Set motion estimation method. Possible values in decreasing order
	   of speed and	increasing order of quality:

	   zero
	       Use no motion estimation	(default).

	   phods
	   x1
	   log Enable advanced diamond zonal search for	16x16 blocks and half-
	       pixel refinement	for 16x16 blocks. x1 and log are aliases for
	       phods.

	   epzs
	       Enable all of the things	described above, plus advanced diamond
	       zonal search for	8x8 blocks, half-pixel refinement for 8x8
	       blocks, and motion estimation on	chroma planes.

	   full
	       Enable all of the things	described above, plus extended 16x16
	       and 8x8 blocks search.

       mbd Set macroblock decision algorithm. Possible values in the
	   increasing order of quality:

	   simple
	       Use macroblock comparing	function algorithm (default).

	   bits
	       Enable rate distortion-based half pixel and quarter pixel
	       refinement for 16x16 blocks.

	   rd  Enable all of the things	described above, plus rate distortion-
	       based half pixel	and quarter pixel refinement for 8x8 blocks,
	       and rate	distortion-based search	using square pattern.

       lumi_aq
	   Enable lumi masking adaptive	quantization when set to 1. Default is
	   0 (disabled).

       variance_aq
	   Enable variance adaptive quantization when set to 1.	Default	is 0
	   (disabled).

	   When	combined with lumi_aq, the resulting quality will not be
	   better than any of the two specified	individually. In other words,
	   the resulting quality will be the worse one of the two effects.

       ssim
	   Set structural similarity (SSIM) displaying method. Possible
	   values:

	   off Disable displaying of SSIM information.

	   avg Output average SSIM at the end of encoding to stdout. The
	       format of showing the average SSIM is:

		       Average SSIM: %f

	       For users who are not familiar with C, %f means a float number,
	       or a decimal (e.g. 0.939232).

	   frame
	       Output both per-frame SSIM data during encoding and average
	       SSIM at the end of encoding to stdout. The format of per-frame
	       information is:

			      SSIM: avg: %1.3f min: %1.3f max: %1.3f

	       For users who are not familiar with C, %1.3f means a float
	       number rounded to 3 digits after	the dot	(e.g. 0.932).

       ssim_acc
	   Set SSIM accuracy. Valid options are	integers within	the range of
	   0-4,	while 0	gives the most accurate	result and 4 computes the
	   fastest.

   mpeg2
       MPEG-2 video encoder.

       Options

       seq_disp_ext integer
	   Specifies if	the encoder should write a sequence_display_extension
	   to the output.

	   -1
	   auto
	       Decide automatically to write it	or not (this is	the default)
	       by checking if the data to be written is	different from the
	       default or unspecified values.

	   0
	   never
	       Never write it.

	   1
	   always
	       Always write it.

   png
       PNG image encoder.

       Private options

       dpi integer
	   Set physical	density	of pixels, in dots per inch, unset by default

       dpm integer
	   Set physical	density	of pixels, in dots per meter, unset by default

   ProRes
       Apple ProRes encoder.

       FFmpeg contains 2 ProRes	encoders, the prores-aw	and prores-ks encoder.
       The used	encoder	can be chosen with the "-vcodec" option.

       Private Options for prores-ks

       profile integer
	   Select the ProRes profile to	encode

	   proxy
	   lt
	   standard
	   hq
	   4444
       quant_mat integer
	   Select quantization matrix.

	   auto
	   default
	   proxy
	   lt
	   standard
	   hq

	   If set to auto, the matrix matching the profile will	be picked.  If
	   not set, the	matrix providing the highest quality, default, will be
	   picked.

       bits_per_mb integer
	   How many bits to allot for coding one macroblock. Different
	   profiles use	between	200 and	2400 bits per macroblock, the maximum
	   is 8000.

       mbs_per_slice integer
	   Number of macroblocks in each slice (1-8); the default value	(8)
	   should be good in almost all	situations.

       vendor string
	   Override the	4-byte vendor ID.  A custom vendor ID like apl0	would
	   claim the stream was	produced by the	Apple encoder.

       alpha_bits integer
	   Specify number of bits for alpha component.	Possible values	are 0,
	   8 and 16.  Use 0 to disable alpha plane coding.

       Speed considerations

       In the default mode of operation	the encoder has	to honor frame
       constraints (i.e. not produce frames with size bigger than requested)
       while still making output picture as good as possible.  A frame
       containing a lot	of small details is harder to compress and the encoder
       would spend more	time searching for appropriate quantizers for each
       slice.

       Setting a higher	bits_per_mb limit will improve the speed.

       For the fastest encoding	speed set the qscale parameter (4 is the
       recommended value) and do not set a size	constraint.

   QSV encoders
       The family of Intel QuickSync Video encoders (MPEG-2, H.264 and HEVC)

       The ratecontrol method is selected as follows:

       o   When	global_quality is specified, a quality-based mode is used.
	   Specifically	this means either

	   -   CQP - constant quantizer	scale, when the	qscale codec flag is
	       also set	(the -qscale ffmpeg option).

	   -   LA_ICQ -	intelligent constant quality with lookahead, when the
	       look_ahead option is also set.

	   -   ICQ -- intelligent constant quality otherwise.

       o   Otherwise, a	bitrate-based mode is used. For	all of those, you
	   should specify at least the desired average bitrate with the	b
	   option.

	   -   LA - VBR	with lookahead,	when the look_ahead option is
	       specified.

	   -   VCM - video conferencing	mode, when the vcm option is set.

	   -   CBR - constant bitrate, when maxrate is specified and equal to
	       the average bitrate.

	   -   VBR - variable bitrate, when maxrate is specified, but is
	       higher than the average bitrate.

	   -   AVBR - average VBR mode,	when maxrate is	not specified. This
	       mode is further configured by the avbr_accuracy and
	       avbr_convergence	options.

       Note that depending on your system, a different mode than the one you
       specified may be	selected by the	encoder. Set the verbosity level to
       verbose or higher to see	the actual settings used by the	QSV runtime.

       Additional libavcodec global options are	mapped to MSDK options as
       follows:

       o   g/gop_size -> GopPicSize

       o   bf/max_b_frames+1 ->	GopRefDist

       o   rc_init_occupancy/rc_initial_buffer_occupancy -> InitialDelayInKB

       o   slices -> NumSlice

       o   refs	-> NumRefFrame

       o   b_strategy/b_frame_strategy -> BRefType

       o   cgop/CLOSED_GOP codec flag -> GopOptFlag

       o   For the CQP mode, the i_qfactor/i_qoffset and b_qfactor/b_qoffset
	   set the difference between QPP and QPI, and QPP and QPB
	   respectively.

       o   Setting the coder option to the value vlc will make the H.264
	   encoder use CAVLC instead of	CABAC.

   snow
       Options

       iterative_dia_size
	   dia size for	the iterative motion estimation

   vc2
       SMPTE VC-2 (previously BBC Dirac	Pro). This codec was primarily aimed
       at professional broadcasting but	since it supports yuv420, yuv422 and
       yuv444 at 8 (limited range or full range), 10 or	12 bits, this makes it
       suitable	for other tasks	which require low overhead and low compression
       (like screen recording).

       Options

       b   Sets	target video bitrate. Usually that's around 1:6	of the
	   uncompressed	video bitrate (e.g. for	1920x1080 50fps	yuv422p10
	   that's around 400Mbps). Higher values (close	to the uncompressed
	   bitrate) turn on lossless compression mode.

       field_order
	   Enables field coding	when set (e.g. to tt - top field first)	for
	   interlaced inputs. Should increase compression with interlaced
	   content as it splits	the fields and encodes each separately.

       wavelet_depth
	   Sets	the total amount of wavelet transforms to apply, between 1 and
	   5 (default).	 Lower values reduce compression and quality. Less
	   capable decoders may	not be able to handle values of	wavelet_depth
	   over	3.

       wavelet_type
	   Sets	the transform type. Currently only 5_3 (LeGall)	and 9_7
	   (Deslauriers-Dubuc) are implemented,	with 9_7 being the one with
	   better compression and thus is the default.

       slice_width
       slice_height
	   Sets	the slice size for each	slice. Larger values result in better
	   compression.	 For compatibility with	other more limited decoders
	   use slice_width of 32 and slice_height of 8.

       tolerance
	   Sets	the undershoot tolerance of the	rate control system in
	   percent. This is to prevent an expensive search from	being run.

       qm  Sets	the quantization matrix	preset to use by default or when
	   wavelet_depth is set	to 5

	   -   default Uses the	default	quantization matrix from the
	       specifications, extended	with values for	the fifth level. This
	       provides	a good balance between keeping detail and omitting
	       artifacts.

	   -   flat Use	a completely zeroed out	quantization matrix. This
	       increases PSNR but might	reduce perception. Use in bogus
	       benchmarks.

	   -   color Reduces detail but	attempts to preserve color at
	       extremely low bitrates.

SUBTITLES ENCODERS
   dvdsub
       This codec encodes the bitmap subtitle format that is used in DVDs.
       Typically they are stored in VOBSUB file	pairs (*.idx + *.sub), and
       they can	also be	used in	Matroska files.

       Options

       even_rows_fix
	   When	set to 1, enable a work-around that makes the number of	pixel
	   rows	even in	all subtitles.	This fixes a problem with some players
	   that	cut off	the bottom row if the number is	odd.  The work-around
	   just	adds a fully transparent row if	needed.	 The overhead is low,
	   typically one byte per subtitle on average.

	   By default, this work-around	is disabled.

SEE ALSO
       ffmpeg(1), ffplay(1), ffprobe(1), ffserver(1), libavcodec(3)

AUTHORS
       The FFmpeg developers.

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

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

							      FFMPEG-CODECS(1)

NAME | DESCRIPTION | CODEC OPTIONS | DECODERS | VIDEO DECODERS | AUDIO DECODERS | SUBTITLES DECODERS | ENCODERS | AUDIO ENCODERS | VIDEO ENCODERS | SUBTITLES ENCODERS | SEE ALSO | AUTHORS

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