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.\" ========================================================================
.\"
.IX Title "FFMPEG-CODECS 1"
.TH FFMPEG-CODECS 1 "2013-12-14" " " " "
.SH "NAME"
ffmpeg\-codecs \- FFmpeg codecs
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
This document describes the codecs (decoders and encoders) provided by
the libavcodec library.
.SH "CODEC OPTIONS"
.IX Header "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.
.PP
Sometimes, a global option may only affect a specific kind of codec,
and may be unsensical 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.
.PP
Options may be set by specifying \-\fIoption\fR \fIvalue\fR in the
FFmpeg tools, or by setting the value explicitly in the
\&\f(CW\*(C`AVCodecContext\*(C'\fR options or using the \fIlibavutil/opt.h\fR \s-1API\s0
for programmatic use.
.PP
The list of supported options follow:
.IP "\fBb\fR \fIinteger\fR \fB(\fR\fIencoding,audio,video\fR\fB)\fR" 4
.IX Item "b integer (encoding,audio,video)"
Set bitrate in bits/s. Default value is 200K.
.IP "\fBab\fR \fIinteger\fR \fB(\fR\fIencoding,audio\fR\fB)\fR" 4
.IX Item "ab integer (encoding,audio)"
Set audio bitrate (in bits/s). Default value is 128K.
.IP "\fBbt\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "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.
.IP "\fBflags\fR \fIflags\fR \fB(\fR\fIdecoding/encoding,audio,video,subtitles\fR\fB)\fR" 4
.IX Item "flags flags (decoding/encoding,audio,video,subtitles)"
Set generic flags.
.Sp
Possible values:
.RS 4
.IP "\fBmv4\fR" 4
.IX Item "mv4"
Use four motion vector by macroblock (mpeg4).
.IP "\fBqpel\fR" 4
.IX Item "qpel"
Use 1/4 pel motion compensation.
.IP "\fBloop\fR" 4
.IX Item "loop"
Use loop filter.
.IP "\fBqscale\fR" 4
.IX Item "qscale"
Use fixed qscale.
.IP "\fBgmc\fR" 4
.IX Item "gmc"
Use gmc.
.IP "\fBmv0\fR" 4
.IX Item "mv0"
Always try a mb with mv=<0,0>.
.IP "\fBinput_preserved\fR" 4
.IX Item "input_preserved"
.PD 0
.IP "\fBpass1\fR" 4
.IX Item "pass1"
.PD
Use internal 2pass ratecontrol in first pass mode.
.IP "\fBpass2\fR" 4
.IX Item "pass2"
Use internal 2pass ratecontrol in second pass mode.
.IP "\fBgray\fR" 4
.IX Item "gray"
Only decode/encode grayscale.
.IP "\fBemu_edge\fR" 4
.IX Item "emu_edge"
Do not draw edges.
.IP "\fBpsnr\fR" 4
.IX Item "psnr"
Set error[?] variables during encoding.
.IP "\fBtruncated\fR" 4
.IX Item "truncated"
.PD 0
.IP "\fBnaq\fR" 4
.IX Item "naq"
.PD
Normalize adaptive quantization.
.IP "\fBildct\fR" 4
.IX Item "ildct"
Use interlaced \s-1DCT\s0.
.IP "\fBlow_delay\fR" 4
.IX Item "low_delay"
Force low delay.
.IP "\fBglobal_header\fR" 4
.IX Item "global_header"
Place global headers in extradata instead of every keyframe.
.IP "\fBbitexact\fR" 4
.IX Item "bitexact"
Use only bitexact stuff (except (I)DCT).
.IP "\fBaic\fR" 4
.IX Item "aic"
Apply H263 advanced intra coding / mpeg4 ac prediction.
.IP "\fBcbp\fR" 4
.IX Item "cbp"
Deprecated, use mpegvideo private options instead.
.IP "\fBqprd\fR" 4
.IX Item "qprd"
Deprecated, use mpegvideo private options instead.
.IP "\fBilme\fR" 4
.IX Item "ilme"
Apply interlaced motion estimation.
.IP "\fBcgop\fR" 4
.IX Item "cgop"
Use closed gop.
.RE
.RS 4
.RE
.IP "\fBme_method\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "me_method integer (encoding,video)"
Set motion estimation method.
.Sp
Possible values:
.RS 4
.IP "\fBzero\fR" 4
.IX Item "zero"
zero motion estimation (fastest)
.IP "\fBfull\fR" 4
.IX Item "full"
full motion estimation (slowest)
.IP "\fBepzs\fR" 4
.IX Item "epzs"
\&\s-1EPZS\s0 motion estimation (default)
.IP "\fBesa\fR" 4
.IX Item "esa"
esa motion estimation (alias for full)
.IP "\fBtesa\fR" 4
.IX Item "tesa"
tesa motion estimation
.IP "\fBdia\fR" 4
.IX Item "dia"
dia motion estimation (alias for epzs)
.IP "\fBlog\fR" 4
.IX Item "log"
log motion estimation
.IP "\fBphods\fR" 4
.IX Item "phods"
phods motion estimation
.IP "\fBx1\fR" 4
.IX Item "x1"
X1 motion estimation
.IP "\fBhex\fR" 4
.IX Item "hex"
hex motion estimation
.IP "\fBumh\fR" 4
.IX Item "umh"
umh motion estimation
.IP "\fBiter\fR" 4
.IX Item "iter"
iter motion estimation
.RE
.RS 4
.RE
.IP "\fBextradata_size\fR \fIinteger\fR" 4
.IX Item "extradata_size integer"
Set extradata size.
.IP "\fBtime_base\fR \fIrational number\fR" 4
.IX Item "time_base rational number"
Set codec time base.
.Sp
It is the fundamental unit of time (in seconds) in terms of which
frame timestamps are represented. For fixed-fps content, timebase
should be \f(CW\*(C`1 / frame_rate\*(C'\fR and timestamp increments should be
identically 1.
.IP "\fBg\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "g integer (encoding,video)"
Set the group of picture size. Default value is 12.
.IP "\fBar\fR \fIinteger\fR \fB(\fR\fIdecoding/encoding,audio\fR\fB)\fR" 4
.IX Item "ar integer (decoding/encoding,audio)"
Set audio sampling rate (in Hz).
.IP "\fBac\fR \fIinteger\fR \fB(\fR\fIdecoding/encoding,audio\fR\fB)\fR" 4
.IX Item "ac integer (decoding/encoding,audio)"
Set number of audio channels.
.IP "\fBcutoff\fR \fIinteger\fR \fB(\fR\fIencoding,audio\fR\fB)\fR" 4
.IX Item "cutoff integer (encoding,audio)"
Set cutoff bandwidth.
.IP "\fBframe_size\fR \fIinteger\fR \fB(\fR\fIencoding,audio\fR\fB)\fR" 4
.IX Item "frame_size integer (encoding,audio)"
Set audio frame size.
.Sp
Each submitted frame except the last must contain exactly frame_size
samples per channel. May be 0 when the codec has
\&\s-1CODEC_CAP_VARIABLE_FRAME_SIZE\s0 set, in that case the frame size is not
restricted. It is set by some decoders to indicate constant frame
size.
.IP "\fBframe_number\fR \fIinteger\fR" 4
.IX Item "frame_number integer"
Set the frame number.
.IP "\fBdelay\fR \fIinteger\fR" 4
.IX Item "delay integer"
.PD 0
.IP "\fBqcomp\fR \fIfloat\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "qcomp float (encoding,video)"
.PD
Set video quantizer scale compression (\s-1VBR\s0). It is used as a constant
in the ratecontrol equation. Recommended range for default rc_eq:
0.0\-1.0.
.IP "\fBqblur\fR \fIfloat\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "qblur float (encoding,video)"
Set video quantizer scale blur (\s-1VBR\s0).
.IP "\fBqmin\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "qmin integer (encoding,video)"
Set min video quantizer scale (\s-1VBR\s0). Must be included between \-1 and
69, default value is 2.
.IP "\fBqmax\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "qmax integer (encoding,video)"
Set max video quantizer scale (\s-1VBR\s0). Must be included between \-1 and
1024, default value is 31.
.IP "\fBqdiff\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "qdiff integer (encoding,video)"
Set max difference between the quantizer scale (\s-1VBR\s0).
.IP "\fBbf\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "bf integer (encoding,video)"
Set max number of B frames.
.IP "\fBb_qfactor\fR \fIfloat\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "b_qfactor float (encoding,video)"
Set qp factor between P and B frames.
.IP "\fBrc_strategy\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "rc_strategy integer (encoding,video)"
Set ratecontrol method.
.IP "\fBb_strategy\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "b_strategy integer (encoding,video)"
Set strategy to choose between I/P/B\-frames.
.IP "\fBps\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "ps integer (encoding,video)"
Set \s-1RTP\s0 payload size in bytes.
.IP "\fBmv_bits\fR \fIinteger\fR" 4
.IX Item "mv_bits integer"
.PD 0
.IP "\fBheader_bits\fR \fIinteger\fR" 4
.IX Item "header_bits integer"
.IP "\fBi_tex_bits\fR \fIinteger\fR" 4
.IX Item "i_tex_bits integer"
.IP "\fBp_tex_bits\fR \fIinteger\fR" 4
.IX Item "p_tex_bits integer"
.IP "\fBi_count\fR \fIinteger\fR" 4
.IX Item "i_count integer"
.IP "\fBp_count\fR \fIinteger\fR" 4
.IX Item "p_count integer"
.IP "\fBskip_count\fR \fIinteger\fR" 4
.IX Item "skip_count integer"
.IP "\fBmisc_bits\fR \fIinteger\fR" 4
.IX Item "misc_bits integer"
.IP "\fBframe_bits\fR \fIinteger\fR" 4
.IX Item "frame_bits integer"
.IP "\fBcodec_tag\fR \fIinteger\fR" 4
.IX Item "codec_tag integer"
.IP "\fBbug\fR \fIflags\fR \fB(\fR\fIdecoding,video\fR\fB)\fR" 4
.IX Item "bug flags (decoding,video)"
.PD
Workaround not auto detected encoder bugs.
.Sp
Possible values:
.RS 4
.IP "\fBautodetect\fR" 4
.IX Item "autodetect"
.PD 0
.IP "\fBold_msmpeg4\fR" 4
.IX Item "old_msmpeg4"
.PD
some old lavc generated msmpeg4v3 files (no autodetection)
.IP "\fBxvid_ilace\fR" 4
.IX Item "xvid_ilace"
Xvid interlacing bug (autodetected if fourcc==XVIX)
.IP "\fBump4\fR" 4
.IX Item "ump4"
(autodetected if fourcc==UMP4)
.IP "\fBno_padding\fR" 4
.IX Item "no_padding"
padding bug (autodetected)
.IP "\fBamv\fR" 4
.IX Item "amv"
.PD 0
.IP "\fBac_vlc\fR" 4
.IX Item "ac_vlc"
.PD
illegal vlc bug (autodetected per fourcc)
.IP "\fBqpel_chroma\fR" 4
.IX Item "qpel_chroma"
.PD 0
.IP "\fBstd_qpel\fR" 4
.IX Item "std_qpel"
.PD
old standard qpel (autodetected per fourcc/version)
.IP "\fBqpel_chroma2\fR" 4
.IX Item "qpel_chroma2"
.PD 0
.IP "\fBdirect_blocksize\fR" 4
.IX Item "direct_blocksize"
.PD
direct-qpel-blocksize bug (autodetected per fourcc/version)
.IP "\fBedge\fR" 4
.IX Item "edge"
edge padding bug (autodetected per fourcc/version)
.IP "\fBhpel_chroma\fR" 4
.IX Item "hpel_chroma"
.PD 0
.IP "\fBdc_clip\fR" 4
.IX Item "dc_clip"
.IP "\fBms\fR" 4
.IX Item "ms"
.PD
Workaround various bugs in microsoft broken decoders.
.IP "\fBtrunc\fR" 4
.IX Item "trunc"
trancated frames
.RE
.RS 4
.RE
.IP "\fBlelim\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "lelim integer (encoding,video)"
Set single coefficient elimination threshold for luminance (negative
values also consider \s-1DC\s0 coefficient).
.IP "\fBcelim\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "celim integer (encoding,video)"
Set single coefficient elimination threshold for chrominance (negative
values also consider dc coefficient)
.IP "\fBstrict\fR \fIinteger\fR \fB(\fR\fIdecoding/encoding,audio,video\fR\fB)\fR" 4
.IX Item "strict integer (decoding/encoding,audio,video)"
Specify how strictly to follow the standards.
.Sp
Possible values:
.RS 4
.IP "\fBvery\fR" 4
.IX Item "very"
strictly conform to a older more strict version of the spec or reference software
.IP "\fBstrict\fR" 4
.IX Item "strict"
strictly conform to all the things in the spec no matter what consequences
.IP "\fBnormal\fR" 4
.IX Item "normal"
.PD 0
.IP "\fBunofficial\fR" 4
.IX Item "unofficial"
.PD
allow unofficial extensions
.IP "\fBexperimental\fR" 4
.IX Item "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.
.RE
.RS 4
.RE
.IP "\fBb_qoffset\fR \fIfloat\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "b_qoffset float (encoding,video)"
Set \s-1QP\s0 offset between P and B frames.
.IP "\fBerr_detect\fR \fIflags\fR \fB(\fR\fIdecoding,audio,video\fR\fB)\fR" 4
.IX Item "err_detect flags (decoding,audio,video)"
Set error detection flags.
.Sp
Possible values:
.RS 4
.IP "\fBcrccheck\fR" 4
.IX Item "crccheck"
verify embedded CRCs
.IP "\fBbitstream\fR" 4
.IX Item "bitstream"
detect bitstream specification deviations
.IP "\fBbuffer\fR" 4
.IX Item "buffer"
detect improper bitstream length
.IP "\fBexplode\fR" 4
.IX Item "explode"
abort decoding on minor error detection
.IP "\fBcareful\fR" 4
.IX Item "careful"
consider things that violate the spec and have not been seen in the wild as errors
.IP "\fBcompliant\fR" 4
.IX Item "compliant"
consider all spec non compliancies as errors
.IP "\fBaggressive\fR" 4
.IX Item "aggressive"
consider things that a sane encoder should not do as an error
.RE
.RS 4
.RE
.IP "\fBhas_b_frames\fR \fIinteger\fR" 4
.IX Item "has_b_frames integer"
.PD 0
.IP "\fBblock_align\fR \fIinteger\fR" 4
.IX Item "block_align integer"
.IP "\fBmpeg_quant\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "mpeg_quant integer (encoding,video)"
.PD
Use \s-1MPEG\s0 quantizers instead of H.263.
.IP "\fBqsquish\fR \fIfloat\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "qsquish float (encoding,video)"
How to keep quantizer between qmin and qmax (0 = clip, 1 = use
differentiable function).
.IP "\fBrc_qmod_amp\fR \fIfloat\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "rc_qmod_amp float (encoding,video)"
Set experimental quantizer modulation.
.IP "\fBrc_qmod_freq\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "rc_qmod_freq integer (encoding,video)"
Set experimental quantizer modulation.
.IP "\fBrc_override_count\fR \fIinteger\fR" 4
.IX Item "rc_override_count integer"
.PD 0
.IP "\fBrc_eq\fR \fIstring\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "rc_eq string (encoding,video)"
.PD
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.
.IP "\fBmaxrate\fR \fIinteger\fR \fB(\fR\fIencoding,audio,video\fR\fB)\fR" 4
.IX Item "maxrate integer (encoding,audio,video)"
Set max bitrate tolerance (in bits/s). Requires bufsize to be set.
.IP "\fBminrate\fR \fIinteger\fR \fB(\fR\fIencoding,audio,video\fR\fB)\fR" 4
.IX Item "minrate integer (encoding,audio,video)"
Set min bitrate tolerance (in bits/s). Most useful in setting up a \s-1CBR\s0
encode. It is of little use elsewise.
.IP "\fBbufsize\fR \fIinteger\fR \fB(\fR\fIencoding,audio,video\fR\fB)\fR" 4
.IX Item "bufsize integer (encoding,audio,video)"
Set ratecontrol buffer size (in bits).
.IP "\fBrc_buf_aggressivity\fR \fIfloat\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "rc_buf_aggressivity float (encoding,video)"
Currently useless.
.IP "\fBi_qfactor\fR \fIfloat\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "i_qfactor float (encoding,video)"
Set \s-1QP\s0 factor between P and I frames.
.IP "\fBi_qoffset\fR \fIfloat\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "i_qoffset float (encoding,video)"
Set \s-1QP\s0 offset between P and I frames.
.IP "\fBrc_init_cplx\fR \fIfloat\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "rc_init_cplx float (encoding,video)"
Set initial complexity for 1\-pass encoding.
.IP "\fBdct\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "dct integer (encoding,video)"
Set \s-1DCT\s0 algorithm.
.Sp
Possible values:
.RS 4
.IP "\fBauto\fR" 4
.IX Item "auto"
autoselect a good one (default)
.IP "\fBfastint\fR" 4
.IX Item "fastint"
fast integer
.IP "\fBint\fR" 4
.IX Item "int"
accurate integer
.IP "\fBmmx\fR" 4
.IX Item "mmx"
.PD 0
.IP "\fBaltivec\fR" 4
.IX Item "altivec"
.IP "\fBfaan\fR" 4
.IX Item "faan"
.PD
floating point \s-1AAN\s0 \s-1DCT\s0
.RE
.RS 4
.RE
.IP "\fBlumi_mask\fR \fIfloat\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "lumi_mask float (encoding,video)"
Compress bright areas stronger than medium ones.
.IP "\fBtcplx_mask\fR \fIfloat\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "tcplx_mask float (encoding,video)"
Set temporal complexity masking.
.IP "\fBscplx_mask\fR \fIfloat\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "scplx_mask float (encoding,video)"
Set spatial complexity masking.
.IP "\fBp_mask\fR \fIfloat\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "p_mask float (encoding,video)"
Set inter masking.
.IP "\fBdark_mask\fR \fIfloat\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "dark_mask float (encoding,video)"
Compress dark areas stronger than medium ones.
.IP "\fBidct\fR \fIinteger\fR \fB(\fR\fIdecoding/encoding,video\fR\fB)\fR" 4
.IX Item "idct integer (decoding/encoding,video)"
Select \s-1IDCT\s0 implementation.
.Sp
Possible values:
.RS 4
.IP "\fBauto\fR" 4
.IX Item "auto"
.PD 0
.IP "\fBint\fR" 4
.IX Item "int"
.IP "\fBsimple\fR" 4
.IX Item "simple"
.IP "\fBsimplemmx\fR" 4
.IX Item "simplemmx"
.IP "\fBarm\fR" 4
.IX Item "arm"
.IP "\fBaltivec\fR" 4
.IX Item "altivec"
.IP "\fBsh4\fR" 4
.IX Item "sh4"
.IP "\fBsimplearm\fR" 4
.IX Item "simplearm"
.IP "\fBsimplearmv5te\fR" 4
.IX Item "simplearmv5te"
.IP "\fBsimplearmv6\fR" 4
.IX Item "simplearmv6"
.IP "\fBsimpleneon\fR" 4
.IX Item "simpleneon"
.IP "\fBsimplealpha\fR" 4
.IX Item "simplealpha"
.IP "\fBipp\fR" 4
.IX Item "ipp"
.IP "\fBxvidmmx\fR" 4
.IX Item "xvidmmx"
.IP "\fBfaani\fR" 4
.IX Item "faani"
.PD
floating point \s-1AAN\s0 \s-1IDCT\s0
.RE
.RS 4
.RE
.IP "\fBslice_count\fR \fIinteger\fR" 4
.IX Item "slice_count integer"
.PD 0
.IP "\fBec\fR \fIflags\fR \fB(\fR\fIdecoding,video\fR\fB)\fR" 4
.IX Item "ec flags (decoding,video)"
.PD
Set error concealment strategy.
.Sp
Possible values:
.RS 4
.IP "\fBguess_mvs\fR" 4
.IX Item "guess_mvs"
iterative motion vector (\s-1MV\s0) search (slow)
.IP "\fBdeblock\fR" 4
.IX Item "deblock"
use strong deblock filter for damaged MBs
.RE
.RS 4
.RE
.IP "\fBbits_per_coded_sample\fR \fIinteger\fR" 4
.IX Item "bits_per_coded_sample integer"
.PD 0
.IP "\fBpred\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "pred integer (encoding,video)"
.PD
Set prediction method.
.Sp
Possible values:
.RS 4
.IP "\fBleft\fR" 4
.IX Item "left"
.PD 0
.IP "\fBplane\fR" 4
.IX Item "plane"
.IP "\fBmedian\fR" 4
.IX Item "median"
.RE
.RS 4
.RE
.IP "\fBaspect\fR \fIrational number\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "aspect rational number (encoding,video)"
.PD
Set sample aspect ratio.
.IP "\fBdebug\fR \fIflags\fR \fB(\fR\fIdecoding/encoding,audio,video,subtitles\fR\fB)\fR" 4
.IX Item "debug flags (decoding/encoding,audio,video,subtitles)"
Print specific debug info.
.Sp
Possible values:
.RS 4
.IP "\fBpict\fR" 4
.IX Item "pict"
picture info
.IP "\fBrc\fR" 4
.IX Item "rc"
rate control
.IP "\fBbitstream\fR" 4
.IX Item "bitstream"
.PD 0
.IP "\fBmb_type\fR" 4
.IX Item "mb_type"
.PD
macroblock (\s-1MB\s0) type
.IP "\fBqp\fR" 4
.IX Item "qp"
per-block quantization parameter (\s-1QP\s0)
.IP "\fBmv\fR" 4
.IX Item "mv"
motion vector
.IP "\fBdct_coeff\fR" 4
.IX Item "dct_coeff"
.PD 0
.IP "\fBskip\fR" 4
.IX Item "skip"
.IP "\fBstartcode\fR" 4
.IX Item "startcode"
.IP "\fBpts\fR" 4
.IX Item "pts"
.IP "\fBer\fR" 4
.IX Item "er"
.PD
error recognition
.IP "\fBmmco\fR" 4
.IX Item "mmco"
memory management control operations (H.264)
.IP "\fBbugs\fR" 4
.IX Item "bugs"
.PD 0
.IP "\fBvis_qp\fR" 4
.IX Item "vis_qp"
.PD
visualize quantization parameter (\s-1QP\s0), lower \s-1QP\s0 are tinted greener
.IP "\fBvis_mb_type\fR" 4
.IX Item "vis_mb_type"
visualize block types
.IP "\fBbuffers\fR" 4
.IX Item "buffers"
picture buffer allocations
.IP "\fBthread_ops\fR" 4
.IX Item "thread_ops"
threading operations
.RE
.RS 4
.RE
.IP "\fBvismv\fR \fIinteger\fR \fB(\fR\fIdecoding,video\fR\fB)\fR" 4
.IX Item "vismv integer (decoding,video)"
Visualize motion vectors (MVs).
.Sp
Possible values:
.RS 4
.IP "\fBpf\fR" 4
.IX Item "pf"
forward predicted MVs of P\-frames
.IP "\fBbf\fR" 4
.IX Item "bf"
forward predicted MVs of B\-frames
.IP "\fBbb\fR" 4
.IX Item "bb"
backward predicted MVs of B\-frames
.RE
.RS 4
.RE
.IP "\fBcmp\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "cmp integer (encoding,video)"
Set full pel me compare function.
.Sp
Possible values:
.RS 4
.IP "\fBsad\fR" 4
.IX Item "sad"
sum of absolute differences, fast (default)
.IP "\fBsse\fR" 4
.IX Item "sse"
sum of squared errors
.IP "\fBsatd\fR" 4
.IX Item "satd"
sum of absolute Hadamard transformed differences
.IP "\fBdct\fR" 4
.IX Item "dct"
sum of absolute \s-1DCT\s0 transformed differences
.IP "\fBpsnr\fR" 4
.IX Item "psnr"
sum of squared quantization errors (avoid, low quality)
.IP "\fBbit\fR" 4
.IX Item "bit"
number of bits needed for the block
.IP "\fBrd\fR" 4
.IX Item "rd"
rate distortion optimal, slow
.IP "\fBzero\fR" 4
.IX Item "zero"
0
.IP "\fBvsad\fR" 4
.IX Item "vsad"
sum of absolute vertical differences
.IP "\fBvsse\fR" 4
.IX Item "vsse"
sum of squared vertical differences
.IP "\fBnsse\fR" 4
.IX Item "nsse"
noise preserving sum of squared differences
.IP "\fBw53\fR" 4
.IX Item "w53"
5/3 wavelet, only used in snow
.IP "\fBw97\fR" 4
.IX Item "w97"
9/7 wavelet, only used in snow
.IP "\fBdctmax\fR" 4
.IX Item "dctmax"
.PD 0
.IP "\fBchroma\fR" 4
.IX Item "chroma"
.RE
.RS 4
.RE
.IP "\fBsubcmp\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "subcmp integer (encoding,video)"
.PD
Set sub pel me compare function.
.Sp
Possible values:
.RS 4
.IP "\fBsad\fR" 4
.IX Item "sad"
sum of absolute differences, fast (default)
.IP "\fBsse\fR" 4
.IX Item "sse"
sum of squared errors
.IP "\fBsatd\fR" 4
.IX Item "satd"
sum of absolute Hadamard transformed differences
.IP "\fBdct\fR" 4
.IX Item "dct"
sum of absolute \s-1DCT\s0 transformed differences
.IP "\fBpsnr\fR" 4
.IX Item "psnr"
sum of squared quantization errors (avoid, low quality)
.IP "\fBbit\fR" 4
.IX Item "bit"
number of bits needed for the block
.IP "\fBrd\fR" 4
.IX Item "rd"
rate distortion optimal, slow
.IP "\fBzero\fR" 4
.IX Item "zero"
0
.IP "\fBvsad\fR" 4
.IX Item "vsad"
sum of absolute vertical differences
.IP "\fBvsse\fR" 4
.IX Item "vsse"
sum of squared vertical differences
.IP "\fBnsse\fR" 4
.IX Item "nsse"
noise preserving sum of squared differences
.IP "\fBw53\fR" 4
.IX Item "w53"
5/3 wavelet, only used in snow
.IP "\fBw97\fR" 4
.IX Item "w97"
9/7 wavelet, only used in snow
.IP "\fBdctmax\fR" 4
.IX Item "dctmax"
.PD 0
.IP "\fBchroma\fR" 4
.IX Item "chroma"
.RE
.RS 4
.RE
.IP "\fBmbcmp\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "mbcmp integer (encoding,video)"
.PD
Set macroblock compare function.
.Sp
Possible values:
.RS 4
.IP "\fBsad\fR" 4
.IX Item "sad"
sum of absolute differences, fast (default)
.IP "\fBsse\fR" 4
.IX Item "sse"
sum of squared errors
.IP "\fBsatd\fR" 4
.IX Item "satd"
sum of absolute Hadamard transformed differences
.IP "\fBdct\fR" 4
.IX Item "dct"
sum of absolute \s-1DCT\s0 transformed differences
.IP "\fBpsnr\fR" 4
.IX Item "psnr"
sum of squared quantization errors (avoid, low quality)
.IP "\fBbit\fR" 4
.IX Item "bit"
number of bits needed for the block
.IP "\fBrd\fR" 4
.IX Item "rd"
rate distortion optimal, slow
.IP "\fBzero\fR" 4
.IX Item "zero"
0
.IP "\fBvsad\fR" 4
.IX Item "vsad"
sum of absolute vertical differences
.IP "\fBvsse\fR" 4
.IX Item "vsse"
sum of squared vertical differences
.IP "\fBnsse\fR" 4
.IX Item "nsse"
noise preserving sum of squared differences
.IP "\fBw53\fR" 4
.IX Item "w53"
5/3 wavelet, only used in snow
.IP "\fBw97\fR" 4
.IX Item "w97"
9/7 wavelet, only used in snow
.IP "\fBdctmax\fR" 4
.IX Item "dctmax"
.PD 0
.IP "\fBchroma\fR" 4
.IX Item "chroma"
.RE
.RS 4
.RE
.IP "\fBildctcmp\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "ildctcmp integer (encoding,video)"
.PD
Set interlaced dct compare function.
.Sp
Possible values:
.RS 4
.IP "\fBsad\fR" 4
.IX Item "sad"
sum of absolute differences, fast (default)
.IP "\fBsse\fR" 4
.IX Item "sse"
sum of squared errors
.IP "\fBsatd\fR" 4
.IX Item "satd"
sum of absolute Hadamard transformed differences
.IP "\fBdct\fR" 4
.IX Item "dct"
sum of absolute \s-1DCT\s0 transformed differences
.IP "\fBpsnr\fR" 4
.IX Item "psnr"
sum of squared quantization errors (avoid, low quality)
.IP "\fBbit\fR" 4
.IX Item "bit"
number of bits needed for the block
.IP "\fBrd\fR" 4
.IX Item "rd"
rate distortion optimal, slow
.IP "\fBzero\fR" 4
.IX Item "zero"
0
.IP "\fBvsad\fR" 4
.IX Item "vsad"
sum of absolute vertical differences
.IP "\fBvsse\fR" 4
.IX Item "vsse"
sum of squared vertical differences
.IP "\fBnsse\fR" 4
.IX Item "nsse"
noise preserving sum of squared differences
.IP "\fBw53\fR" 4
.IX Item "w53"
5/3 wavelet, only used in snow
.IP "\fBw97\fR" 4
.IX Item "w97"
9/7 wavelet, only used in snow
.IP "\fBdctmax\fR" 4
.IX Item "dctmax"
.PD 0
.IP "\fBchroma\fR" 4
.IX Item "chroma"
.RE
.RS 4
.RE
.IP "\fBdia_size\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "dia_size integer (encoding,video)"
.PD
Set diamond type & size for motion estimation.
.IP "\fBlast_pred\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "last_pred integer (encoding,video)"
Set amount of motion predictors from the previous frame.
.IP "\fBpreme\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "preme integer (encoding,video)"
Set pre motion estimation.
.IP "\fBprecmp\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "precmp integer (encoding,video)"
Set pre motion estimation compare function.
.Sp
Possible values:
.RS 4
.IP "\fBsad\fR" 4
.IX Item "sad"
sum of absolute differences, fast (default)
.IP "\fBsse\fR" 4
.IX Item "sse"
sum of squared errors
.IP "\fBsatd\fR" 4
.IX Item "satd"
sum of absolute Hadamard transformed differences
.IP "\fBdct\fR" 4
.IX Item "dct"
sum of absolute \s-1DCT\s0 transformed differences
.IP "\fBpsnr\fR" 4
.IX Item "psnr"
sum of squared quantization errors (avoid, low quality)
.IP "\fBbit\fR" 4
.IX Item "bit"
number of bits needed for the block
.IP "\fBrd\fR" 4
.IX Item "rd"
rate distortion optimal, slow
.IP "\fBzero\fR" 4
.IX Item "zero"
0
.IP "\fBvsad\fR" 4
.IX Item "vsad"
sum of absolute vertical differences
.IP "\fBvsse\fR" 4
.IX Item "vsse"
sum of squared vertical differences
.IP "\fBnsse\fR" 4
.IX Item "nsse"
noise preserving sum of squared differences
.IP "\fBw53\fR" 4
.IX Item "w53"
5/3 wavelet, only used in snow
.IP "\fBw97\fR" 4
.IX Item "w97"
9/7 wavelet, only used in snow
.IP "\fBdctmax\fR" 4
.IX Item "dctmax"
.PD 0
.IP "\fBchroma\fR" 4
.IX Item "chroma"
.RE
.RS 4
.RE
.IP "\fBpre_dia_size\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "pre_dia_size integer (encoding,video)"
.PD
Set diamond type & size for motion estimation pre\-pass.
.IP "\fBsubq\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "subq integer (encoding,video)"
Set sub pel motion estimation quality.
.IP "\fBdtg_active_format\fR \fIinteger\fR" 4
.IX Item "dtg_active_format integer"
.PD 0
.IP "\fBme_range\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "me_range integer (encoding,video)"
.PD
Set limit motion vectors range (1023 for DivX player).
.IP "\fBibias\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "ibias integer (encoding,video)"
Set intra quant bias.
.IP "\fBpbias\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "pbias integer (encoding,video)"
Set inter quant bias.
.IP "\fBcolor_table_id\fR \fIinteger\fR" 4
.IX Item "color_table_id integer"
.PD 0
.IP "\fBglobal_quality\fR \fIinteger\fR \fB(\fR\fIencoding,audio,video\fR\fB)\fR" 4
.IX Item "global_quality integer (encoding,audio,video)"
.IP "\fBcoder\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "coder integer (encoding,video)"
.PD
Possible values:
.RS 4
.IP "\fBvlc\fR" 4
.IX Item "vlc"
variable length coder / huffman coder
.IP "\fBac\fR" 4
.IX Item "ac"
arithmetic coder
.IP "\fBraw\fR" 4
.IX Item "raw"
raw (no encoding)
.IP "\fBrle\fR" 4
.IX Item "rle"
run-length coder
.IP "\fBdeflate\fR" 4
.IX Item "deflate"
deflate-based coder
.RE
.RS 4
.RE
.IP "\fBcontext\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "context integer (encoding,video)"
Set context model.
.IP "\fBslice_flags\fR \fIinteger\fR" 4
.IX Item "slice_flags integer"
.PD 0
.IP "\fBxvmc_acceleration\fR \fIinteger\fR" 4
.IX Item "xvmc_acceleration integer"
.IP "\fBmbd\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "mbd integer (encoding,video)"
.PD
Set macroblock decision algorithm (high quality mode).
.Sp
Possible values:
.RS 4
.IP "\fBsimple\fR" 4
.IX Item "simple"
use mbcmp (default)
.IP "\fBbits\fR" 4
.IX Item "bits"
use fewest bits
.IP "\fBrd\fR" 4
.IX Item "rd"
use best rate distortion
.RE
.RS 4
.RE
.IP "\fBstream_codec_tag\fR \fIinteger\fR" 4
.IX Item "stream_codec_tag integer"
.PD 0
.IP "\fBsc_threshold\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "sc_threshold integer (encoding,video)"
.PD
Set scene change threshold.
.IP "\fBlmin\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "lmin integer (encoding,video)"
Set min lagrange factor (\s-1VBR\s0).
.IP "\fBlmax\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "lmax integer (encoding,video)"
Set max lagrange factor (\s-1VBR\s0).
.IP "\fBnr\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "nr integer (encoding,video)"
Set noise reduction.
.IP "\fBrc_init_occupancy\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "rc_init_occupancy integer (encoding,video)"
Set number of bits which should be loaded into the rc buffer before
decoding starts.
.IP "\fBflags2\fR \fIflags\fR \fB(\fR\fIdecoding/encoding,audio,video\fR\fB)\fR" 4
.IX Item "flags2 flags (decoding/encoding,audio,video)"
Possible values:
.RS 4
.IP "\fBfast\fR" 4
.IX Item "fast"
Allow non spec compliant speedup tricks.
.IP "\fBsgop\fR" 4
.IX Item "sgop"
Deprecated, use mpegvideo private options instead.
.IP "\fBnoout\fR" 4
.IX Item "noout"
Skip bitstream encoding.
.IP "\fBignorecrop\fR" 4
.IX Item "ignorecrop"
Ignore cropping information from sps.
.IP "\fBlocal_header\fR" 4
.IX Item "local_header"
Place global headers at every keyframe instead of in extradata.
.IP "\fBchunks\fR" 4
.IX Item "chunks"
Frame data might be split into multiple chunks.
.IP "\fBshowall\fR" 4
.IX Item "showall"
Show all frames before the first keyframe.
.IP "\fBskiprd\fR" 4
.IX Item "skiprd"
Deprecated, use mpegvideo private options instead.
.RE
.RS 4
.RE
.IP "\fBerror\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "error integer (encoding,video)"
.PD 0
.IP "\fBqns\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "qns integer (encoding,video)"
.PD
Deprecated, use mpegvideo private options instead.
.IP "\fBthreads\fR \fIinteger\fR \fB(\fR\fIdecoding/encoding,video\fR\fB)\fR" 4
.IX Item "threads integer (decoding/encoding,video)"
Possible values:
.RS 4
.IP "\fBauto\fR" 4
.IX Item "auto"
detect a good number of threads
.RE
.RS 4
.RE
.IP "\fBme_threshold\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "me_threshold integer (encoding,video)"
Set motion estimation threshold.
.IP "\fBmb_threshold\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "mb_threshold integer (encoding,video)"
Set macroblock threshold.
.IP "\fBdc\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "dc integer (encoding,video)"
Set intra_dc_precision.
.IP "\fBnssew\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "nssew integer (encoding,video)"
Set nsse weight.
.IP "\fBskip_top\fR \fIinteger\fR \fB(\fR\fIdecoding,video\fR\fB)\fR" 4
.IX Item "skip_top integer (decoding,video)"
Set number of macroblock rows at the top which are skipped.
.IP "\fBskip_bottom\fR \fIinteger\fR \fB(\fR\fIdecoding,video\fR\fB)\fR" 4
.IX Item "skip_bottom integer (decoding,video)"
Set number of macroblock rows at the bottom which are skipped.
.IP "\fBprofile\fR \fIinteger\fR \fB(\fR\fIencoding,audio,video\fR\fB)\fR" 4
.IX Item "profile integer (encoding,audio,video)"
Possible values:
.RS 4
.IP "\fBunknown\fR" 4
.IX Item "unknown"
.PD 0
.IP "\fBaac_main\fR" 4
.IX Item "aac_main"
.IP "\fBaac_low\fR" 4
.IX Item "aac_low"
.IP "\fBaac_ssr\fR" 4
.IX Item "aac_ssr"
.IP "\fBaac_ltp\fR" 4
.IX Item "aac_ltp"
.IP "\fBaac_he\fR" 4
.IX Item "aac_he"
.IP "\fBaac_he_v2\fR" 4
.IX Item "aac_he_v2"
.IP "\fBaac_ld\fR" 4
.IX Item "aac_ld"
.IP "\fBaac_eld\fR" 4
.IX Item "aac_eld"
.IP "\fBmpeg2_aac_low\fR" 4
.IX Item "mpeg2_aac_low"
.IP "\fBmpeg2_aac_he\fR" 4
.IX Item "mpeg2_aac_he"
.IP "\fBdts\fR" 4
.IX Item "dts"
.IP "\fBdts_es\fR" 4
.IX Item "dts_es"
.IP "\fBdts_96_24\fR" 4
.IX Item "dts_96_24"
.IP "\fBdts_hd_hra\fR" 4
.IX Item "dts_hd_hra"
.IP "\fBdts_hd_ma\fR" 4
.IX Item "dts_hd_ma"
.RE
.RS 4
.RE
.IP "\fBlevel\fR \fIinteger\fR \fB(\fR\fIencoding,audio,video\fR\fB)\fR" 4
.IX Item "level integer (encoding,audio,video)"
.PD
Possible values:
.RS 4
.IP "\fBunknown\fR" 4
.IX Item "unknown"
.RE
.RS 4
.RE
.PD 0
.IP "\fBlowres\fR \fIinteger\fR \fB(\fR\fIdecoding,audio,video\fR\fB)\fR" 4
.IX Item "lowres integer (decoding,audio,video)"
.PD
Decode at 1= 1/2, 2=1/4, 3=1/8 resolutions.
.IP "\fBskip_threshold\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "skip_threshold integer (encoding,video)"
Set frame skip threshold.
.IP "\fBskip_factor\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "skip_factor integer (encoding,video)"
Set frame skip factor.
.IP "\fBskip_exp\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "skip_exp integer (encoding,video)"
Set frame skip exponent.
.IP "\fBskipcmp\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "skipcmp integer (encoding,video)"
Set frame skip compare function.
.Sp
Possible values:
.RS 4
.IP "\fBsad\fR" 4
.IX Item "sad"
sum of absolute differences, fast (default)
.IP "\fBsse\fR" 4
.IX Item "sse"
sum of squared errors
.IP "\fBsatd\fR" 4
.IX Item "satd"
sum of absolute Hadamard transformed differences
.IP "\fBdct\fR" 4
.IX Item "dct"
sum of absolute \s-1DCT\s0 transformed differences
.IP "\fBpsnr\fR" 4
.IX Item "psnr"
sum of squared quantization errors (avoid, low quality)
.IP "\fBbit\fR" 4
.IX Item "bit"
number of bits needed for the block
.IP "\fBrd\fR" 4
.IX Item "rd"
rate distortion optimal, slow
.IP "\fBzero\fR" 4
.IX Item "zero"
0
.IP "\fBvsad\fR" 4
.IX Item "vsad"
sum of absolute vertical differences
.IP "\fBvsse\fR" 4
.IX Item "vsse"
sum of squared vertical differences
.IP "\fBnsse\fR" 4
.IX Item "nsse"
noise preserving sum of squared differences
.IP "\fBw53\fR" 4
.IX Item "w53"
5/3 wavelet, only used in snow
.IP "\fBw97\fR" 4
.IX Item "w97"
9/7 wavelet, only used in snow
.IP "\fBdctmax\fR" 4
.IX Item "dctmax"
.PD 0
.IP "\fBchroma\fR" 4
.IX Item "chroma"
.RE
.RS 4
.RE
.IP "\fBborder_mask\fR \fIfloat\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "border_mask float (encoding,video)"
.PD
Increase the quantizer for macroblocks close to borders.
.IP "\fBmblmin\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "mblmin integer (encoding,video)"
Set min macroblock lagrange factor (\s-1VBR\s0).
.IP "\fBmblmax\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "mblmax integer (encoding,video)"
Set max macroblock lagrange factor (\s-1VBR\s0).
.IP "\fBmepc\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "mepc integer (encoding,video)"
Set motion estimation bitrate penalty compensation (1.0 = 256).
.IP "\fBskip_loop_filter\fR \fIinteger\fR \fB(\fR\fIdecoding,video\fR\fB)\fR" 4
.IX Item "skip_loop_filter integer (decoding,video)"
.PD 0
.IP "\fBskip_idct\fR        \fIinteger\fR \fB(\fR\fIdecoding,video\fR\fB)\fR" 4
.IX Item "skip_idct        integer (decoding,video)"
.IP "\fBskip_frame\fR       \fIinteger\fR \fB(\fR\fIdecoding,video\fR\fB)\fR" 4
.IX Item "skip_frame       integer (decoding,video)"
.PD
Make decoder discard processing depending on the frame type selected
by the option value.
.Sp
\&\fBskip_loop_filter\fR skips frame loop filtering, \fBskip_idct\fR
skips frame IDCT/dequantization, \fBskip_frame\fR skips decoding.
.Sp
Possible values:
.RS 4
.IP "\fBnone\fR" 4
.IX Item "none"
Discard no frame.
.IP "\fBdefault\fR" 4
.IX Item "default"
Discard useless frames like 0\-sized frames.
.IP "\fBnoref\fR" 4
.IX Item "noref"
Discard all non-reference frames.
.IP "\fBbidir\fR" 4
.IX Item "bidir"
Discard all bidirectional frames.
.IP "\fBnokey\fR" 4
.IX Item "nokey"
Discard all frames excepts keyframes.
.IP "\fBall\fR" 4
.IX Item "all"
Discard all frames.
.RE
.RS 4
.Sp
Default value is \fBdefault\fR.
.RE
.IP "\fBbidir_refine\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "bidir_refine integer (encoding,video)"
Refine the two motion vectors used in bidirectional macroblocks.
.IP "\fBbrd_scale\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "brd_scale integer (encoding,video)"
Downscale frames for dynamic B\-frame decision.
.IP "\fBkeyint_min\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "keyint_min integer (encoding,video)"
Set minimum interval between IDR\-frames.
.IP "\fBrefs\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "refs integer (encoding,video)"
Set reference frames to consider for motion compensation.
.IP "\fBchromaoffset\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "chromaoffset integer (encoding,video)"
Set chroma qp offset from luma.
.IP "\fBtrellis\fR \fIinteger\fR \fB(\fR\fIencoding,audio,video\fR\fB)\fR" 4
.IX Item "trellis integer (encoding,audio,video)"
Set rate-distortion optimal quantization.
.IP "\fBsc_factor\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "sc_factor integer (encoding,video)"
Set value multiplied by qscale for each frame and added to
scene_change_score.
.IP "\fBmv0_threshold\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "mv0_threshold integer (encoding,video)"
.PD 0
.IP "\fBb_sensitivity\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "b_sensitivity integer (encoding,video)"
.PD
Adjust sensitivity of b_frame_strategy 1.
.IP "\fBcompression_level\fR \fIinteger\fR \fB(\fR\fIencoding,audio,video\fR\fB)\fR" 4
.IX Item "compression_level integer (encoding,audio,video)"
.PD 0
.IP "\fBmin_prediction_order\fR \fIinteger\fR \fB(\fR\fIencoding,audio\fR\fB)\fR" 4
.IX Item "min_prediction_order integer (encoding,audio)"
.IP "\fBmax_prediction_order\fR \fIinteger\fR \fB(\fR\fIencoding,audio\fR\fB)\fR" 4
.IX Item "max_prediction_order integer (encoding,audio)"
.IP "\fBtimecode_frame_start\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "timecode_frame_start integer (encoding,video)"
.PD
Set \s-1GOP\s0 timecode frame start number, in non drop frame format.
.IP "\fBrequest_channels\fR \fIinteger\fR \fB(\fR\fIdecoding,audio\fR\fB)\fR" 4
.IX Item "request_channels integer (decoding,audio)"
Set desired number of audio channels.
.IP "\fBbits_per_raw_sample\fR \fIinteger\fR" 4
.IX Item "bits_per_raw_sample integer"
.PD 0
.IP "\fBchannel_layout\fR \fIinteger\fR \fB(\fR\fIdecoding/encoding,audio\fR\fB)\fR" 4
.IX Item "channel_layout integer (decoding/encoding,audio)"
.PD
Possible values:
.RS 4
.RE
.RS 4
.RE
.IP "\fBrequest_channel_layout\fR \fIinteger\fR \fB(\fR\fIdecoding,audio\fR\fB)\fR" 4
.IX Item "request_channel_layout integer (decoding,audio)"
Possible values:
.RS 4
.RE
.RS 4
.RE
.IP "\fBrc_max_vbv_use\fR \fIfloat\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "rc_max_vbv_use float (encoding,video)"
.PD 0
.IP "\fBrc_min_vbv_use\fR \fIfloat\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "rc_min_vbv_use float (encoding,video)"
.IP "\fBticks_per_frame\fR \fIinteger\fR \fB(\fR\fIdecoding/encoding,audio,video\fR\fB)\fR" 4
.IX Item "ticks_per_frame integer (decoding/encoding,audio,video)"
.IP "\fBcolor_primaries\fR \fIinteger\fR \fB(\fR\fIdecoding/encoding,video\fR\fB)\fR" 4
.IX Item "color_primaries integer (decoding/encoding,video)"
.IP "\fBcolor_trc\fR \fIinteger\fR \fB(\fR\fIdecoding/encoding,video\fR\fB)\fR" 4
.IX Item "color_trc integer (decoding/encoding,video)"
.IP "\fBcolorspace\fR \fIinteger\fR \fB(\fR\fIdecoding/encoding,video\fR\fB)\fR" 4
.IX Item "colorspace integer (decoding/encoding,video)"
.IP "\fBcolor_range\fR \fIinteger\fR \fB(\fR\fIdecoding/encoding,video\fR\fB)\fR" 4
.IX Item "color_range integer (decoding/encoding,video)"
.IP "\fBchroma_sample_location\fR \fIinteger\fR \fB(\fR\fIdecoding/encoding,video\fR\fB)\fR" 4
.IX Item "chroma_sample_location integer (decoding/encoding,video)"
.IP "\fBlog_level_offset\fR \fIinteger\fR" 4
.IX Item "log_level_offset integer"
.PD
Set the log level offset.
.IP "\fBslices\fR \fIinteger\fR \fB(\fR\fIencoding,video\fR\fB)\fR" 4
.IX Item "slices integer (encoding,video)"
Number of slices, used in parallelized encoding.
.IP "\fBthread_type\fR \fIflags\fR \fB(\fR\fIdecoding/encoding,video\fR\fB)\fR" 4
.IX Item "thread_type flags (decoding/encoding,video)"
Select multithreading type.
.Sp
Possible values:
.RS 4
.IP "\fBslice\fR" 4
.IX Item "slice"
.PD 0
.IP "\fBframe\fR" 4
.IX Item "frame"
.RE
.RS 4
.RE
.IP "\fBaudio_service_type\fR \fIinteger\fR \fB(\fR\fIencoding,audio\fR\fB)\fR" 4
.IX Item "audio_service_type integer (encoding,audio)"
.PD
Set audio service type.
.Sp
Possible values:
.RS 4
.IP "\fBma\fR" 4
.IX Item "ma"
Main Audio Service
.IP "\fBef\fR" 4
.IX Item "ef"
Effects
.IP "\fBvi\fR" 4
.IX Item "vi"
Visually Impaired
.IP "\fBhi\fR" 4
.IX Item "hi"
Hearing Impaired
.IP "\fBdi\fR" 4
.IX Item "di"
Dialogue
.IP "\fBco\fR" 4
.IX Item "co"
Commentary
.IP "\fBem\fR" 4
.IX Item "em"
Emergency
.IP "\fBvo\fR" 4
.IX Item "vo"
Voice Over
.IP "\fBka\fR" 4
.IX Item "ka"
Karaoke
.RE
.RS 4
.RE
.IP "\fBrequest_sample_fmt\fR \fIsample_fmt\fR \fB(\fR\fIdecoding,audio\fR\fB)\fR" 4
.IX Item "request_sample_fmt sample_fmt (decoding,audio)"
Set sample format audio decoders should prefer. Default value is
\&\f(CW\*(C`none\*(C'\fR.
.IP "\fBpkt_timebase\fR \fIrational number\fR" 4
.IX Item "pkt_timebase rational number"
.PD 0
.IP "\fBsub_charenc\fR \fIencoding\fR \fB(\fR\fIdecoding,subtitles\fR\fB)\fR" 4
.IX Item "sub_charenc encoding (decoding,subtitles)"
.PD
Set the input subtitles character encoding.
.IP "\fBfield_order\fR  \fIfield_order\fR \fB(\fR\fIvideo\fR\fB)\fR" 4
.IX Item "field_order  field_order (video)"
Set/override the field order of the video.
Possible values:
.RS 4
.IP "\fBprogressive\fR" 4
.IX Item "progressive"
Progressive video
.IP "\fBtt\fR" 4
.IX Item "tt"
Interlaced video, top field coded and displayed first
.IP "\fBbb\fR" 4
.IX Item "bb"
Interlaced video, bottom field coded and displayed first
.IP "\fBtb\fR" 4
.IX Item "tb"
Interlaced video, top coded first, bottom displayed first
.IP "\fBbt\fR" 4
.IX Item "bt"
Interlaced video, bottom coded first, top displayed first
.RE
.RS 4
.RE
.IP "\fBskip_alpha\fR \fIinteger\fR \fB(\fR\fIdecoding,video\fR\fB)\fR" 4
.IX Item "skip_alpha integer (decoding,video)"
Set to 1 to disable processing alpha (transparency). This works like the
\&\fBgray\fR flag in the \fBflags\fR option which skips chroma information
instead of alpha. Default is 0.
.SH "DECODERS"
.IX Header "DECODERS"
Decoders are configured elements in FFmpeg which allow the decoding of
multimedia streams.
.PP
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 \f(CW\*(C`\-\-enable\-lib\*(C'\fR option. You can list all
available decoders using the configure option \f(CW\*(C`\-\-list\-decoders\*(C'\fR.
.PP
You can disable all the decoders with the configure option
\&\f(CW\*(C`\-\-disable\-decoders\*(C'\fR and selectively enable / disable single decoders
with the options \f(CW\*(C`\-\-enable\-decoder=\f(CI\s-1DECODER\s0\f(CW\*(C'\fR /
\&\f(CW\*(C`\-\-disable\-decoder=\f(CI\s-1DECODER\s0\f(CW\*(C'\fR.
.PP
The option \f(CW\*(C`\-codecs\*(C'\fR of the ff* tools will display the list of
enabled decoders.
.SH "VIDEO DECODERS"
.IX Header "VIDEO DECODERS"
A description of some of the currently available video decoders
follows.
.Sh "rawvideo"
.IX Subsection "rawvideo"
Raw video decoder.
.PP
This decoder decodes rawvideo streams.
.PP
\fIOptions\fR
.IX Subsection "Options"
.IP "\fBtop\fR \fItop_field_first\fR" 4
.IX Item "top top_field_first"
Specify the assumed field type of the input video.
.RS 4
.IP "\fB\-1\fR" 4
.IX Item "-1"
the video is assumed to be progressive (default)
.IP "\fB0\fR" 4
.IX Item "0"
bottom-field-first is assumed
.IP "\fB1\fR" 4
.IX Item "1"
top-field-first is assumed
.RE
.RS 4
.RE
.SH "AUDIO DECODERS"
.IX Header "AUDIO DECODERS"
.Sh "ffwavesynth"
.IX Subsection "ffwavesynth"
Internal wave synthetizer.
.PP
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.
.Sh "libcelt"
.IX Subsection "libcelt"
libcelt decoder wrapper.
.PP
libcelt allows libavcodec to decode the Xiph \s-1CELT\s0 ultra-low delay audio codec.
Requires the presence of the libcelt headers and library during configuration.
You need to explicitly configure the build with \f(CW\*(C`\-\-enable\-libcelt\*(C'\fR.
.Sh "libgsm"
.IX Subsection "libgsm"
libgsm decoder wrapper.
.PP
libgsm allows libavcodec to decode the \s-1GSM\s0 full rate audio codec. Requires
the presence of the libgsm headers and library during configuration. You need
to explicitly configure the build with \f(CW\*(C`\-\-enable\-libgsm\*(C'\fR.
.PP
This decoder supports both the ordinary \s-1GSM\s0 and the Microsoft variant.
.Sh "libilbc"
.IX Subsection "libilbc"
libilbc decoder wrapper.
.PP
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
\&\f(CW\*(C`\-\-enable\-libilbc\*(C'\fR.
.PP
\fIOptions\fR
.IX Subsection "Options"
.PP
The following option is supported by the libilbc wrapper.
.IP "\fBenhance\fR" 4
.IX Item "enhance"
Enable the enhancement of the decoded audio when set to 1. The default
value is 0 (disabled).
.Sh "libopencore-amrnb"
.IX Subsection "libopencore-amrnb"
libopencore-amrnb decoder wrapper.
.PP
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 \f(CW\*(C`\-\-enable\-libopencore\-amrnb\*(C'\fR.
.PP
An FFmpeg native decoder for AMR-NB exists, so users can decode AMR-NB
without this library.
.Sh "libopencore-amrwb"
.IX Subsection "libopencore-amrwb"
libopencore-amrwb decoder wrapper.
.PP
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 \f(CW\*(C`\-\-enable\-libopencore\-amrwb\*(C'\fR.
.PP
An FFmpeg native decoder for AMR-WB exists, so users can decode AMR-WB
without this library.
.Sh "libopus"
.IX Subsection "libopus"
libopus decoder wrapper.
.PP
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
\&\f(CW\*(C`\-\-enable\-libopus\*(C'\fR.
.SH "SUBTITLES DECODERS"
.IX Header "SUBTITLES DECODERS"
.Sh "dvdsub"
.IX Subsection "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.
.PP
\fIOptions\fR
.IX Subsection "Options"
.IP "\fBpalette\fR" 4
.IX Item "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 \s-1IFO\s0 file, and therefore not available when reading
from dumped \s-1VOB\s0 files.
.Sp
The format for this option is a string containing 16 24\-bits hexadecimal
numbers (without 0x prefix) separated by comas, for example \f(CW\*(C`0d00ee,
ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1,
7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b\*(C'\fR.
.Sh "libzvbi-teletext"
.IX Subsection "libzvbi-teletext"
Libzvbi allows libavcodec to decode \s-1DVB\s0 teletext pages and \s-1DVB\s0 teletext
subtitles. Requires the presence of the libzvbi headers and library during
configuration. You need to explicitly configure the build with
\&\f(CW\*(C`\-\-enable\-libzvbi\*(C'\fR.
.PP
\fIOptions\fR
.IX Subsection "Options"
.IP "\fBtxt_page\fR" 4
.IX Item "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 *.
.IP "\fBtxt_chop_top\fR" 4
.IX Item "txt_chop_top"
Discards the top teletext line. Default value is 1.
.IP "\fBtxt_format\fR" 4
.IX Item "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
\&\*(L"bitmap\*(R" for teletext pages, because certain graphics and colors cannot be
expressed in simple text. You might use \*(L"text\*(R" for teletext based subtitles if
your application can handle simple text based subtitles. Default value is
bitmap.
.IP "\fBtxt_left\fR" 4
.IX Item "txt_left"
X offset of generated bitmaps, default is 0.
.IP "\fBtxt_top\fR" 4
.IX Item "txt_top"
Y offset of generated bitmaps, default is 0.
.IP "\fBtxt_chop_spaces\fR" 4
.IX Item "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.
.IP "\fBtxt_duration\fR" 4
.IX Item "txt_duration"
Sets the display duration of the decoded teletext pages or subtitles in
miliseconds. Default value is 30000 which is 30 seconds.
.IP "\fBtxt_transparent\fR" 4
.IX Item "txt_transparent"
Force transparent background of the generated teletext bitmaps. Default value
is 0 which means an opaque (black) background.
.SH "ENCODERS"
.IX Header "ENCODERS"
Encoders are configured elements in FFmpeg which allow the encoding of
multimedia streams.
.PP
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 \f(CW\*(C`\-\-enable\-lib\*(C'\fR option. You can list all
available encoders using the configure option \f(CW\*(C`\-\-list\-encoders\*(C'\fR.
.PP
You can disable all the encoders with the configure option
\&\f(CW\*(C`\-\-disable\-encoders\*(C'\fR and selectively enable / disable single encoders
with the options \f(CW\*(C`\-\-enable\-encoder=\f(CI\s-1ENCODER\s0\f(CW\*(C'\fR /
\&\f(CW\*(C`\-\-disable\-encoder=\f(CI\s-1ENCODER\s0\f(CW\*(C'\fR.
.PP
The option \f(CW\*(C`\-codecs\*(C'\fR of the ff* tools will display the list of
enabled encoders.
.SH "AUDIO ENCODERS"
.IX Header "AUDIO ENCODERS"
A description of some of the currently available audio encoders
follows.
.Sh "aac"
.IX Subsection "aac"
Advanced Audio Coding (\s-1AAC\s0) encoder.
.PP
This encoder is an experimental FFmpeg-native \s-1AAC\s0 encoder. Currently only the
low complexity (\s-1AAC\-LC\s0) profile is supported. To use this encoder, you must set
\&\fBstrict\fR option to \fBexperimental\fR or lower.
.PP
As this encoder is experimental, unexpected behavior may exist from time to
time. For a more stable \s-1AAC\s0 encoder, see libvo\-aacenc. However, be warned
that it has a worse quality reported by some users.
.PP
\fIOptions\fR
.IX Subsection "Options"
.IP "\fBb\fR" 4
.IX Item "b"
Set bit rate in bits/s. Setting this automatically activates constant bit rate
(\s-1CBR\s0) mode.
.IP "\fBq\fR" 4
.IX Item "q"
Set quality for variable bit rate (\s-1VBR\s0) mode. This option is valid only using
the \fBffmpeg\fR command-line tool. For library interface users, use
\&\fBglobal_quality\fR.
.IP "\fBstereo_mode\fR" 4
.IX Item "stereo_mode"
Set stereo encoding mode. Possible values:
.RS 4
.IP "\fBauto\fR" 4
.IX Item "auto"
Automatically selected by the encoder.
.IP "\fBms_off\fR" 4
.IX Item "ms_off"
Disable middle/side encoding. This is the default.
.IP "\fBms_force\fR" 4
.IX Item "ms_force"
Force middle/side encoding.
.RE
.RS 4
.RE
.IP "\fBaac_coder\fR" 4
.IX Item "aac_coder"
Set \s-1AAC\s0 encoder coding method. Possible values:
.RS 4
.IP "\fBfaac\fR" 4
.IX Item "faac"
FAAC-inspired method.
.Sp
This method is a simplified reimplementation of the method used in \s-1FAAC\s0, which
sets thresholds proportional to the band energies, and then decreases all the
thresholds with quantizer steps to find the appropriate quantization with
distortion below threshold band by band.
.Sp
The quality of this method is comparable to the two loop searching method
descibed below, but somewhat a little better and slower.
.IP "\fBanmr\fR" 4
.IX Item "anmr"
Average noise to mask ratio (\s-1ANMR\s0) trellis-based solution.
.Sp
This has a theoretic best quality out of all the coding methods, but at the
cost of the slowest speed.
.IP "\fBtwoloop\fR" 4
.IX Item "twoloop"
Two loop searching (\s-1TLS\s0) method.
.Sp
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.
.Sp
This method produces similar quality with the \s-1FAAC\s0 method and is the default.
.IP "\fBfast\fR" 4
.IX Item "fast"
Constant quantizer method.
.Sp
This method sets a constant quantizer for all bands. This is the fastest of all
the methods, yet produces the worst quality.
.RE
.RS 4
.RE
.Sh "ac3 and ac3_fixed"
.IX Subsection "ac3 and ac3_fixed"
\&\s-1AC\-3\s0 audio encoders.
.PP
These encoders implement part of \s-1ATSC\s0 A/52:2010 and \s-1ETSI\s0 \s-1TS\s0 102 366, as well as
the undocumented RealAudio 3 (a.k.a. dnet).
.PP
The \fIac3\fR encoder uses floating-point math, while the \fIac3_fixed\fR
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 \fIac3_fixed\fR encoder is not the
default codec for any of the output formats, so it must be specified explicitly
using the option \f(CW\*(C`\-acodec ac3_fixed\*(C'\fR in order to use it.
.PP
\fI\s-1AC\-3\s0 Metadata\fR
.IX Subsection "AC-3 Metadata"
.PP
The \s-1AC\-3\s0 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.
.PP
These parameters are described in detail in several publicly-available
documents.
.IP "*<<\fBhttp://www.atsc.org/cms/standards/a_52\-2010.pdf\fR>>" 4
.IX Item "*<<http://www.atsc.org/cms/standards/a_52-2010.pdf>>"
.PD 0
.IP "*<<\fBhttp://www.atsc.org/cms/standards/a_54a_with_corr_1.pdf\fR>>" 4
.IX Item "*<<http://www.atsc.org/cms/standards/a_54a_with_corr_1.pdf>>"
.IP "*<<\fBhttp://www.dolby.com/uploadedFiles/zz\-_Shared_Assets/English_PDFs/Professional/18_Metadata.Guide.pdf\fR>>" 4
.IX Item "*<<http://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/18_Metadata.Guide.pdf>>"
.IP "*<<\fBhttp://www.dolby.com/uploadedFiles/zz\-_Shared_Assets/English_PDFs/Professional/46_DDEncodingGuidelines.pdf\fR>>" 4
.IX Item "*<<http://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/46_DDEncodingGuidelines.pdf>>"
.PD
.PP
Metadata Control Options
.IX Subsection "Metadata Control Options"
.IP "\fB\-per_frame_metadata\fR \fIboolean\fR" 4
.IX Item "-per_frame_metadata boolean"
Allow Per-Frame Metadata. Specifies if the encoder should check for changing
metadata for each frame.
.RS 4
.IP "\fB0\fR" 4
.IX Item "0"
The metadata values set at initialization will be used for every frame in the
stream. (default)
.IP "\fB1\fR" 4
.IX Item "1"
Metadata values can be changed before encoding each frame.
.RE
.RS 4
.RE
.PP
Downmix Levels
.IX Subsection "Downmix Levels"
.IP "\fB\-center_mixlev\fR \fIlevel\fR" 4
.IX Item "-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:
.RS 4
.IP "\fB0.707\fR" 4
.IX Item "0.707"
Apply \-3dB gain
.IP "\fB0.595\fR" 4
.IX Item "0.595"
Apply \-4.5dB gain (default)
.IP "\fB0.500\fR" 4
.IX Item "0.500"
Apply \-6dB gain
.RE
.RS 4
.RE
.IP "\fB\-surround_mixlev\fR \fIlevel\fR" 4
.IX Item "-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:
.RS 4
.IP "\fB0.707\fR" 4
.IX Item "0.707"
Apply \-3dB gain
.IP "\fB0.500\fR" 4
.IX Item "0.500"
Apply \-6dB gain (default)
.IP "\fB0.000\fR" 4
.IX Item "0.000"
Silence Surround Channel(s)
.RE
.RS 4
.RE
.PP
Audio Production Information
.IX Subsection "Audio Production Information"
.PP
Audio Production Information is optional information describing the mixing
environment.  Either none or both of the fields are written to the bitstream.
.IP "\fB\-mixing_level\fR \fInumber\fR" 4
.IX Item "-mixing_level number"
Mixing Level. Specifies peak sound pressure level (\s-1SPL\s0) 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 \f(CW\*(C`room_type\*(C'\fR option is not the default value, the \f(CW\*(C`mixing_level\*(C'\fR
option must not be \-1.
.IP "\fB\-room_type\fR \fItype\fR" 4
.IX Item "-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 \f(CW\*(C`mixing_level\*(C'\fR
option and the \f(CW\*(C`room_type\*(C'\fR option have the default values.
.RS 4
.IP "\fB0\fR" 4
.IX Item "0"
.PD 0
.IP "\fBnotindicated\fR" 4
.IX Item "notindicated"
.PD
Not Indicated (default)
.IP "\fB1\fR" 4
.IX Item "1"
.PD 0
.IP "\fBlarge\fR" 4
.IX Item "large"
.PD
Large Room
.IP "\fB2\fR" 4
.IX Item "2"
.PD 0
.IP "\fBsmall\fR" 4
.IX Item "small"
.PD
Small Room
.RE
.RS 4
.RE
.PP
Other Metadata Options
.IX Subsection "Other Metadata Options"
.IP "\fB\-copyright\fR \fIboolean\fR" 4
.IX Item "-copyright boolean"
Copyright Indicator. Specifies whether a copyright exists for this audio.
.RS 4
.IP "\fB0\fR" 4
.IX Item "0"
.PD 0
.IP "\fBoff\fR" 4
.IX Item "off"
.PD
No Copyright Exists (default)
.IP "\fB1\fR" 4
.IX Item "1"
.PD 0
.IP "\fBon\fR" 4
.IX Item "on"
.PD
Copyright Exists
.RE
.RS 4
.RE
.IP "\fB\-dialnorm\fR \fIvalue\fR" 4
.IX Item "-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.
.IP "\fB\-dsur_mode\fR \fImode\fR" 4
.IX Item "-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 \fB\s-1NOT\s0\fR mean the encoder will actually
apply Dolby Surround processing.
.RS 4
.IP "\fB0\fR" 4
.IX Item "0"
.PD 0
.IP "\fBnotindicated\fR" 4
.IX Item "notindicated"
.PD
Not Indicated (default)
.IP "\fB1\fR" 4
.IX Item "1"
.PD 0
.IP "\fBoff\fR" 4
.IX Item "off"
.PD
Not Dolby Surround Encoded
.IP "\fB2\fR" 4
.IX Item "2"
.PD 0
.IP "\fBon\fR" 4
.IX Item "on"
.PD
Dolby Surround Encoded
.RE
.RS 4
.RE
.IP "\fB\-original\fR \fIboolean\fR" 4
.IX Item "-original boolean"
Original Bit Stream Indicator. Specifies whether this audio is from the
original source and not a copy.
.RS 4
.IP "\fB0\fR" 4
.IX Item "0"
.PD 0
.IP "\fBoff\fR" 4
.IX Item "off"
.PD
Not Original Source
.IP "\fB1\fR" 4
.IX Item "1"
.PD 0
.IP "\fBon\fR" 4
.IX Item "on"
.PD
Original Source (default)
.RE
.RS 4
.RE
.PP
\fIExtended Bitstream Information\fR
.IX Subsection "Extended Bitstream Information"
.PP
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 \f(CW\*(C`center_mixlev\*(C'\fR
and \f(CW\*(C`surround_mixlev\*(C'\fR options if it supports the Alternate Bit Stream
Syntax.
.PP
Extended Bitstream Information \- Part 1
.IX Subsection "Extended Bitstream Information - Part 1"
.IP "\fB\-dmix_mode\fR \fImode\fR" 4
.IX Item "-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.
.RS 4
.IP "\fB0\fR" 4
.IX Item "0"
.PD 0
.IP "\fBnotindicated\fR" 4
.IX Item "notindicated"
.PD
Not Indicated (default)
.IP "\fB1\fR" 4
.IX Item "1"
.PD 0
.IP "\fBltrt\fR" 4
.IX Item "ltrt"
.PD
Lt/Rt Downmix Preferred
.IP "\fB2\fR" 4
.IX Item "2"
.PD 0
.IP "\fBloro\fR" 4
.IX Item "loro"
.PD
Lo/Ro Downmix Preferred
.RE
.RS 4
.RE
.IP "\fB\-ltrt_cmixlev\fR \fIlevel\fR" 4
.IX Item "-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.
.RS 4
.IP "\fB1.414\fR" 4
.IX Item "1.414"
Apply +3dB gain
.IP "\fB1.189\fR" 4
.IX Item "1.189"
Apply +1.5dB gain
.IP "\fB1.000\fR" 4
.IX Item "1.000"
Apply 0dB gain
.IP "\fB0.841\fR" 4
.IX Item "0.841"
Apply \-1.5dB gain
.IP "\fB0.707\fR" 4
.IX Item "0.707"
Apply \-3.0dB gain
.IP "\fB0.595\fR" 4
.IX Item "0.595"
Apply \-4.5dB gain (default)
.IP "\fB0.500\fR" 4
.IX Item "0.500"
Apply \-6.0dB gain
.IP "\fB0.000\fR" 4
.IX Item "0.000"
Silence Center Channel
.RE
.RS 4
.RE
.IP "\fB\-ltrt_surmixlev\fR \fIlevel\fR" 4
.IX Item "-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.
.RS 4
.IP "\fB0.841\fR" 4
.IX Item "0.841"
Apply \-1.5dB gain
.IP "\fB0.707\fR" 4
.IX Item "0.707"
Apply \-3.0dB gain
.IP "\fB0.595\fR" 4
.IX Item "0.595"
Apply \-4.5dB gain
.IP "\fB0.500\fR" 4
.IX Item "0.500"
Apply \-6.0dB gain (default)
.IP "\fB0.000\fR" 4
.IX Item "0.000"
Silence Surround Channel(s)
.RE
.RS 4
.RE
.IP "\fB\-loro_cmixlev\fR \fIlevel\fR" 4
.IX Item "-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.
.RS 4
.IP "\fB1.414\fR" 4
.IX Item "1.414"
Apply +3dB gain
.IP "\fB1.189\fR" 4
.IX Item "1.189"
Apply +1.5dB gain
.IP "\fB1.000\fR" 4
.IX Item "1.000"
Apply 0dB gain
.IP "\fB0.841\fR" 4
.IX Item "0.841"
Apply \-1.5dB gain
.IP "\fB0.707\fR" 4
.IX Item "0.707"
Apply \-3.0dB gain
.IP "\fB0.595\fR" 4
.IX Item "0.595"
Apply \-4.5dB gain (default)
.IP "\fB0.500\fR" 4
.IX Item "0.500"
Apply \-6.0dB gain
.IP "\fB0.000\fR" 4
.IX Item "0.000"
Silence Center Channel
.RE
.RS 4
.RE
.IP "\fB\-loro_surmixlev\fR \fIlevel\fR" 4
.IX Item "-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.
.RS 4
.IP "\fB0.841\fR" 4
.IX Item "0.841"
Apply \-1.5dB gain
.IP "\fB0.707\fR" 4
.IX Item "0.707"
Apply \-3.0dB gain
.IP "\fB0.595\fR" 4
.IX Item "0.595"
Apply \-4.5dB gain
.IP "\fB0.500\fR" 4
.IX Item "0.500"
Apply \-6.0dB gain (default)
.IP "\fB0.000\fR" 4
.IX Item "0.000"
Silence Surround Channel(s)
.RE
.RS 4
.RE
.PP
Extended Bitstream Information \- Part 2
.IX Subsection "Extended Bitstream Information - Part 2"
.IP "\fB\-dsurex_mode\fR \fImode\fR" 4
.IX Item "-dsurex_mode mode"
Dolby Surround \s-1EX\s0 Mode. Indicates whether the stream uses Dolby Surround \s-1EX\s0
(7.1 matrixed to 5.1). Using this option does \fB\s-1NOT\s0\fR mean the encoder will actually
apply Dolby Surround \s-1EX\s0 processing.
.RS 4
.IP "\fB0\fR" 4
.IX Item "0"
.PD 0
.IP "\fBnotindicated\fR" 4
.IX Item "notindicated"
.PD
Not Indicated (default)
.IP "\fB1\fR" 4
.IX Item "1"
.PD 0
.IP "\fBon\fR" 4
.IX Item "on"
.PD
Dolby Surround \s-1EX\s0 Off
.IP "\fB2\fR" 4
.IX Item "2"
.PD 0
.IP "\fBoff\fR" 4
.IX Item "off"
.PD
Dolby Surround \s-1EX\s0 On
.RE
.RS 4
.RE
.IP "\fB\-dheadphone_mode\fR \fImode\fR" 4
.IX Item "-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 \fB\s-1NOT\s0\fR mean the encoder will actually apply Dolby Headphone
processing.
.RS 4
.IP "\fB0\fR" 4
.IX Item "0"
.PD 0
.IP "\fBnotindicated\fR" 4
.IX Item "notindicated"
.PD
Not Indicated (default)
.IP "\fB1\fR" 4
.IX Item "1"
.PD 0
.IP "\fBon\fR" 4
.IX Item "on"
.PD
Dolby Headphone Off
.IP "\fB2\fR" 4
.IX Item "2"
.PD 0
.IP "\fBoff\fR" 4
.IX Item "off"
.PD
Dolby Headphone On
.RE
.RS 4
.RE
.IP "\fB\-ad_conv_type\fR \fItype\fR" 4
.IX Item "-ad_conv_type type"
A/D Converter Type. Indicates whether the audio has passed through \s-1HDCD\s0 A/D
conversion.
.RS 4
.IP "\fB0\fR" 4
.IX Item "0"
.PD 0
.IP "\fBstandard\fR" 4
.IX Item "standard"
.PD
Standard A/D Converter (default)
.IP "\fB1\fR" 4
.IX Item "1"
.PD 0
.IP "\fBhdcd\fR" 4
.IX Item "hdcd"
.PD
\&\s-1HDCD\s0 A/D Converter
.RE
.RS 4
.RE
.PP
\fIOther \s-1AC\-3\s0 Encoding Options\fR
.IX Subsection "Other AC-3 Encoding Options"
.IP "\fB\-stereo_rematrixing\fR \fIboolean\fR" 4
.IX Item "-stereo_rematrixing boolean"
Stereo Rematrixing. Enables/Disables use of rematrixing for stereo input. This
is an optional \s-1AC\-3\s0 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.
.PP
\fIFloating-Point-Only \s-1AC\-3\s0 Encoding Options\fR
.IX Subsection "Floating-Point-Only AC-3 Encoding Options"
.PP
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.
.IP "\fB\-channel_coupling\fR \fIboolean\fR" 4
.IX Item "-channel_coupling boolean"
Enables/Disables use of channel coupling, which is an optional \s-1AC\-3\s0 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.
.RS 4
.IP "\fB\-1\fR" 4
.IX Item "-1"
.PD 0
.IP "\fBauto\fR" 4
.IX Item "auto"
.PD
Selected by Encoder (default)
.IP "\fB0\fR" 4
.IX Item "0"
.PD 0
.IP "\fBoff\fR" 4
.IX Item "off"
.PD
Disable Channel Coupling
.IP "\fB1\fR" 4
.IX Item "1"
.PD 0
.IP "\fBon\fR" 4
.IX Item "on"
.PD
Enable Channel Coupling
.RE
.RS 4
.RE
.IP "\fB\-cpl_start_band\fR \fInumber\fR" 4
.IX Item "-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 \fIauto\fR 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.
.RS 4
.IP "\fB\-1\fR" 4
.IX Item "-1"
.PD 0
.IP "\fBauto\fR" 4
.IX Item "auto"
.PD
Selected by Encoder (default)
.RE
.RS 4
.RE
.Sh "libmp3lame"
.IX Subsection "libmp3lame"
\&\s-1LAME\s0 (Lame Ain't an \s-1MP3\s0 Encoder) \s-1MP3\s0 encoder wrapper.
.PP
Requires the presence of the libmp3lame headers and library during
configuration. You need to explicitly configure the build with
\&\f(CW\*(C`\-\-enable\-libmp3lame\*(C'\fR.
.PP
See libshine for a fixed-point \s-1MP3\s0 encoder, although with a
lower quality.
.PP
\fIOptions\fR
.IX Subsection "Options"
.PP
The following options are supported by the libmp3lame wrapper. The
\&\fBlame\fR\-equivalent of the options are listed in parentheses.
.IP "\fBb (\fR\fI\-b\fR\fB)\fR" 4
.IX Item "b (-b)"
Set bitrate expressed in bits/s for \s-1CBR\s0. \s-1LAME\s0 \f(CW\*(C`bitrate\*(C'\fR is
expressed in kilobits/s.
.IP "\fBq (\fR\fI\-V\fR\fB)\fR" 4
.IX Item "q (-V)"
Set constant quality setting for \s-1VBR\s0. This option is valid only
using the \fBffmpeg\fR command-line tool. For library interface
users, use \fBglobal_quality\fR.
.IP "\fBcompression_level (\fR\fI\-q\fR\fB)\fR" 4
.IX Item "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.
.IP "\fBreservoir\fR" 4
.IX Item "reservoir"
Enable use of bit reservoir when set to 1. Default value is 1. \s-1LAME\s0
has this enabled by default, but can be overriden by use
\&\fB\-\-nores\fR option.
.IP "\fBjoint_stereo (\fR\fI\-m j\fR\fB)\fR" 4
.IX Item "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.
.Sh "libopencore-amrnb"
.IX Subsection "libopencore-amrnb"
OpenCORE Adaptive Multi-Rate Narrowband encoder.
.PP
Requires the presence of the libopencore-amrnb headers and library during
configuration. You need to explicitly configure the build with
\&\f(CW\*(C`\-\-enable\-libopencore\-amrnb \-\-enable\-version3\*(C'\fR.
.PP
This is a mono-only encoder. Officially it only supports 8000Hz sample rate,
but you can override it by setting \fBstrict\fR to \fBunofficial\fR or
lower.
.PP
\fIOptions\fR
.IX Subsection "Options"
.IP "\fBb\fR" 4
.IX Item "b"
Set bitrate in bits per second. Only the following bitrates are supported,
otherwise libavcodec will round to the nearest valid bitrate.
.RS 4
.IP "\fB4750\fR" 4
.IX Item "4750"
.PD 0
.IP "\fB5150\fR" 4
.IX Item "5150"
.IP "\fB5900\fR" 4
.IX Item "5900"
.IP "\fB6700\fR" 4
.IX Item "6700"
.IP "\fB7400\fR" 4
.IX Item "7400"
.IP "\fB7950\fR" 4
.IX Item "7950"
.IP "\fB10200\fR" 4
.IX Item "10200"
.IP "\fB12200\fR" 4
.IX Item "12200"
.RE
.RS 4
.RE
.IP "\fBdtx\fR" 4
.IX Item "dtx"
.PD
Allow discontinuous transmission (generate comfort noise) when set to 1. The
default value is 0 (disabled).
.Sh "libshine"
.IX Subsection "libshine"
Shine Fixed-Point \s-1MP3\s0 encoder wrapper.
.PP
Shine is a fixed-point \s-1MP3\s0 encoder. It has a far better performance on
platforms without an \s-1FPU\s0, 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 \s-1LAME\s0 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.
.PP
This encoder only supports stereo and mono input. This is also CBR\-only.
.PP
The original project (last updated in early 2007) is at
<\fBhttp://sourceforge.net/projects/libshine\-fxp/\fR>. We only support the
updated fork by the Savonet/Liquidsoap project at <\fBhttps://github.com/savonet/shine\fR>.
.PP
Requires the presence of the libshine headers and library during
configuration. You need to explicitly configure the build with
\&\f(CW\*(C`\-\-enable\-libshine\*(C'\fR.
.PP
See also libmp3lame.
.PP
\fIOptions\fR
.IX Subsection "Options"
.PP
The following options are supported by the libshine wrapper. The
\&\fBshineenc\fR\-equivalent of the options are listed in parentheses.
.IP "\fBb (\fR\fI\-b\fR\fB)\fR" 4
.IX Item "b (-b)"
Set bitrate expressed in bits/s for \s-1CBR\s0. \fBshineenc\fR \fB\-b\fR option
is expressed in kilobits/s.
.Sh "libtwolame"
.IX Subsection "libtwolame"
TwoLAME \s-1MP2\s0 encoder wrapper.
.PP
Requires the presence of the libtwolame headers and library during
configuration. You need to explicitly configure the build with
\&\f(CW\*(C`\-\-enable\-libtwolame\*(C'\fR.
.PP
\fIOptions\fR
.IX Subsection "Options"
.PP
The following options are supported by the libtwolame wrapper. The
\&\fBtwolame\fR\-equivalent options follow the FFmpeg ones and are in
parentheses.
.IP "\fBb (\fR\fI\-b\fR\fB)\fR" 4
.IX Item "b (-b)"
Set bitrate expressed in bits/s for \s-1CBR\s0. \fBtwolame\fR \fBb\fR
option is expressed in kilobits/s. Default value is 128k.
.IP "\fBq (\fR\fI\-V\fR\fB)\fR" 4
.IX Item "q (-V)"
Set quality for experimental \s-1VBR\s0 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
\&\fBffmpeg\fR command-line tool. For library interface users,
use \fBglobal_quality\fR.
.IP "\fBmode (\fR\fI\-\-mode\fR\fB)\fR" 4
.IX Item "mode (--mode)"
Set the mode of the resulting audio. Possible values:
.RS 4
.IP "\fBauto\fR" 4
.IX Item "auto"
Choose mode automatically based on the input. This is the default.
.IP "\fBstereo\fR" 4
.IX Item "stereo"
Stereo
.IP "\fBjoint_stereo\fR" 4
.IX Item "joint_stereo"
Joint stereo
.IP "\fBdual_channel\fR" 4
.IX Item "dual_channel"
Dual channel
.IP "\fBmono\fR" 4
.IX Item "mono"
Mono
.RE
.RS 4
.RE
.IP "\fBpsymodel (\fR\fI\-\-psyc\-mode\fR\fB)\fR" 4
.IX Item "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.
.IP "\fBenergy_levels (\fR\fI\-\-energy\fR\fB)\fR" 4
.IX Item "energy_levels (--energy)"
Enable energy levels extensions when set to 1. The default value is
0 (disabled).
.IP "\fBerror_protection (\fR\fI\-\-protect\fR\fB)\fR" 4
.IX Item "error_protection (--protect)"
Enable \s-1CRC\s0 error protection when set to 1. The default value is 0
(disabled).
.IP "\fBcopyright (\fR\fI\-\-copyright\fR\fB)\fR" 4
.IX Item "copyright (--copyright)"
Set \s-1MPEG\s0 audio copyright flag when set to 1. The default value is 0
(disabled).
.IP "\fBoriginal (\fR\fI\-\-original\fR\fB)\fR" 4
.IX Item "original (--original)"
Set \s-1MPEG\s0 audio original flag when set to 1. The default value is 0
(disabled).
.Sh "libvo-aacenc"
.IX Subsection "libvo-aacenc"
VisualOn \s-1AAC\s0 encoder.
.PP
Requires the presence of the libvo-aacenc headers and library during
configuration. You need to explicitly configure the build with
\&\f(CW\*(C`\-\-enable\-libvo\-aacenc \-\-enable\-version3\*(C'\fR.
.PP
This encoder is considered to be worse than the
native experimental FFmpeg \s-1AAC\s0 encoder, according to
multiple sources.
.PP
\fIOptions\fR
.IX Subsection "Options"
.PP
The VisualOn \s-1AAC\s0 encoder only support encoding AAC-LC and up to 2
channels. It is also CBR\-only.
.IP "\fBb\fR" 4
.IX Item "b"
Set bit rate in bits/s.
.Sh "libvo-amrwbenc"
.IX Subsection "libvo-amrwbenc"
VisualOn Adaptive Multi-Rate Wideband encoder.
.PP
Requires the presence of the libvo-amrwbenc headers and library during
configuration. You need to explicitly configure the build with
\&\f(CW\*(C`\-\-enable\-libvo\-amrwbenc \-\-enable\-version3\*(C'\fR.
.PP
This is a mono-only encoder. Officially it only supports 16000Hz sample
rate, but you can override it by setting \fBstrict\fR to
\&\fBunofficial\fR or lower.
.PP
\fIOptions\fR
.IX Subsection "Options"
.IP "\fBb\fR" 4
.IX Item "b"
Set bitrate in bits/s. Only the following bitrates are supported, otherwise
libavcodec will round to the nearest valid bitrate.
.RS 4
.IP "\fB6600\fR" 4
.IX Item "6600"
.PD 0
.IP "\fB8850\fR" 4
.IX Item "8850"
.IP "\fB12650\fR" 4
.IX Item "12650"
.IP "\fB14250\fR" 4
.IX Item "14250"
.IP "\fB15850\fR" 4
.IX Item "15850"
.IP "\fB18250\fR" 4
.IX Item "18250"
.IP "\fB19850\fR" 4
.IX Item "19850"
.IP "\fB23050\fR" 4
.IX Item "23050"
.IP "\fB23850\fR" 4
.IX Item "23850"
.RE
.RS 4
.RE
.IP "\fBdtx\fR" 4
.IX Item "dtx"
.PD
Allow discontinuous transmission (generate comfort noise) when set to 1. The
default value is 0 (disabled).
.Sh "libopus"
.IX Subsection "libopus"
libopus Opus Interactive Audio Codec encoder wrapper.
.PP
Requires the presence of the libopus headers and library during
configuration. You need to explicitly configure the build with
\&\f(CW\*(C`\-\-enable\-libopus\*(C'\fR.
.PP
\fIOption Mapping\fR
.IX Subsection "Option Mapping"
.PP
Most libopus options are modeled after the \fBopusenc\fR utility from
opus\-tools. The following is an option mapping chart describing options
supported by the libopus wrapper, and their \fBopusenc\fR\-equivalent
in parentheses.
.IP "\fBb (\fR\fIbitrate\fR\fB)\fR" 4
.IX Item "b (bitrate)"
Set the bit rate in bits/s.  FFmpeg's \fBb\fR option is
expressed in bits/s, while \fBopusenc\fR's \fBbitrate\fR in
kilobits/s.
.IP "\fBvbr (\fR\fIvbr\fR\fB,\fR \fIhard-cbr\fR\fB, and\fR \fIcvbr\fR\fB)\fR" 4
.IX Item "vbr (vbr, hard-cbr, and cvbr)"
Set \s-1VBR\s0 mode. The FFmpeg \fBvbr\fR option has the following
valid arguments, with the their \fBopusenc\fR equivalent options
in parentheses:
.RS 4
.IP "\fBoff (\fR\fIhard-cbr\fR\fB)\fR" 4
.IX Item "off (hard-cbr)"
Use constant bit rate encoding.
.IP "\fBon (\fR\fIvbr\fR\fB)\fR" 4
.IX Item "on (vbr)"
Use variable bit rate encoding (the default).
.IP "\fBconstrained (\fR\fIcvbr\fR\fB)\fR" 4
.IX Item "constrained (cvbr)"
Use constrained variable bit rate encoding.
.RE
.RS 4
.RE
.IP "\fBcompression_level (\fR\fIcomp\fR\fB)\fR" 4
.IX Item "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.
.IP "\fBframe_duration (\fR\fIframesize\fR\fB)\fR" 4
.IX Item "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 of FFmpeg is 10ms, but is 20ms in \fBopusenc\fR.
.IP "\fBpacket_loss (\fR\fIexpect-loss\fR\fB)\fR" 4
.IX Item "packet_loss (expect-loss)"
Set expected packet loss percentage. The default is 0.
.IP "\fBapplication (N.A.)\fR" 4
.IX Item "application (N.A.)"
Set intended application type. Valid options are listed below:
.RS 4
.IP "\fBvoip\fR" 4
.IX Item "voip"
Favor improved speech intelligibility.
.IP "\fBaudio\fR" 4
.IX Item "audio"
Favor faithfulness to the input (the default).
.IP "\fBlowdelay\fR" 4
.IX Item "lowdelay"
Restrict to only the lowest delay modes.
.RE
.RS 4
.RE
.IP "\fBcutoff (N.A.)\fR" 4
.IX Item "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).
.Sh "libvorbis"
.IX Subsection "libvorbis"
libvorbis encoder wrapper.
.PP
Requires the presence of the libvorbisenc headers and library during
configuration. You need to explicitly configure the build with
\&\f(CW\*(C`\-\-enable\-libvorbis\*(C'\fR.
.PP
\fIOptions\fR
.IX Subsection "Options"
.PP
The following options are supported by the libvorbis wrapper. The
\&\fBoggenc\fR\-equivalent of the options are listed in parentheses.
.PP
To get a more accurate and extensive documentation of the libvorbis
options, consult the libvorbisenc's and \fBoggenc\fR's documentations.
See <\fBhttp://xiph.org/vorbis/\fR>,
<\fBhttp://wiki.xiph.org/Vorbis\-tools\fR>, and \fIoggenc\fR\|(1).
.IP "\fBb (\fR\fI\-b\fR\fB)\fR" 4
.IX Item "b (-b)"
Set bitrate expressed in bits/s for \s-1ABR\s0. \fBoggenc\fR \fB\-b\fR is
expressed in kilobits/s.
.IP "\fBq (\fR\fI\-q\fR\fB)\fR" 4
.IX Item "q (-q)"
Set constant quality setting for \s-1VBR\s0. 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 \fB3.0\fR.
.Sp
This option is valid only using the \fBffmpeg\fR command-line tool.
For library interface users, use \fBglobal_quality\fR.
.IP "\fBcutoff (\fR\fI\-\-advanced\-encode\-option lowpass_frequency=N\fR\fB)\fR" 4
.IX Item "cutoff (--advanced-encode-option lowpass_frequency=N)"
Set cutoff bandwidth in Hz, a value of 0 disables cutoff. \fBoggenc\fR's
related option is expressed in kHz. The default value is \fB0\fR (cutoff
disabled).
.IP "\fBminrate (\fR\fI\-m\fR\fB)\fR" 4
.IX Item "minrate (-m)"
Set minimum bitrate expressed in bits/s. \fBoggenc\fR \fB\-m\fR is
expressed in kilobits/s.
.IP "\fBmaxrate (\fR\fI\-M\fR\fB)\fR" 4
.IX Item "maxrate (-M)"
Set maximum bitrate expressed in bits/s. \fBoggenc\fR \fB\-M\fR is
expressed in kilobits/s. This only has effect on \s-1ABR\s0 mode.
.IP "\fBiblock (\fR\fI\-\-advanced\-encode\-option impulse_noisetune=N\fR\fB)\fR" 4
.IX Item "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.
.Sh "libwavpack"
.IX Subsection "libwavpack"
A wrapper providing WavPack encoding through libwavpack.
.PP
Only lossless mode using 32\-bit integer samples is supported currently.
The \fBcompression_level\fR option can be used to control speed vs.
compression tradeoff, with the values mapped to libwavpack as follows:
.IP "\fB0\fR" 4
.IX Item "0"
Fast mode \- corresponding to the wavpack \fB\-f\fR option.
.IP "\fB1\fR" 4
.IX Item "1"
Normal (default) settings.
.IP "\fB2\fR" 4
.IX Item "2"
High quality \- corresponding to the wavpack \fB\-h\fR option.
.IP "\fB3\fR" 4
.IX Item "3"
Very high quality \- corresponding to the wavpack \fB\-hh\fR option.
.IP "\fB4\-8\fR" 4
.IX Item "4-8"
Same as 3, but with extra processing enabled \- corresponding to the wavpack
\&\fB\-x\fR option. I.e. 4 is the same as \fB\-x2\fR and 8 is the same as
\&\fB\-x6\fR.
.SH "VIDEO ENCODERS"
.IX Header "VIDEO ENCODERS"
A description of some of the currently available video encoders
follows.
.Sh "libtheora"
.IX Subsection "libtheora"
Theora format supported through libtheora.
.PP
Requires the presence of the libtheora headers and library during
configuration. You need to explicitly configure the build with
\&\f(CW\*(C`\-\-enable\-libtheora\*(C'\fR.
.PP
\fIOptions\fR
.IX Subsection "Options"
.PP
The following global options are mapped to internal libtheora options
which affect the quality and the bitrate of the encoded stream.
.IP "\fBb\fR" 4
.IX Item "b"
Set the video bitrate, only works if the \f(CW\*(C`qscale\*(C'\fR flag in
\&\fBflags\fR is not enabled.
.IP "\fBflags\fR" 4
.IX Item "flags"
Used to enable constant quality mode encoding through the
\&\fBqscale\fR flag, and to enable the \f(CW\*(C`pass1\*(C'\fR and \f(CW\*(C`pass2\*(C'\fR
modes.
.IP "\fBg\fR" 4
.IX Item "g"
Set the \s-1GOP\s0 size.
.IP "\fBglobal_quality\fR" 4
.IX Item "global_quality"
Set the global quality in lambda units, only works if the
\&\f(CW\*(C`qscale\*(C'\fR flag in \fBflags\fR is enabled. The value is clipped
in the [0 \- 10*\f(CW\*(C`FF_QP2LAMBDA\*(C'\fR] range, and then multiplied for 6.3
to get a value in the native libtheora range [0\-63]. A higher value
corresponds to a higher quality.
.Sp
For example, to set maximum constant quality encoding with
\&\fBffmpeg\fR:
.Sp
.Vb 1
\&        ffmpeg -i INPUT -flags:v qscale -global_quality:v "10*QP2LAMBDA" -codec:v libtheora OUTPUT.ogg
.Ve
.Sh "libvpx"
.IX Subsection "libvpx"
\&\s-1VP8\s0 format supported through libvpx.
.PP
Requires the presence of the libvpx headers and library during configuration.
You need to explicitly configure the build with \f(CW\*(C`\-\-enable\-libvpx\*(C'\fR.
.PP
\fIOptions\fR
.IX Subsection "Options"
.PP
Mapping from FFmpeg to libvpx options with conversion notes in parentheses.
.IP "\fBthreads\fR" 4
.IX Item "threads"
g_threads
.IP "\fBprofile\fR" 4
.IX Item "profile"
g_profile
.IP "\fBvb\fR" 4
.IX Item "vb"
rc_target_bitrate
.IP "\fBg\fR" 4
.IX Item "g"
kf_max_dist
.IP "\fBkeyint_min\fR" 4
.IX Item "keyint_min"
kf_min_dist
.IP "\fBqmin\fR" 4
.IX Item "qmin"
rc_min_quantizer
.IP "\fBqmax\fR" 4
.IX Item "qmax"
rc_max_quantizer
.IP "\fBbufsize, vb\fR" 4
.IX Item "bufsize, vb"
rc_buf_sz
\&\f(CW\*(C`(bufsize * 1000 / vb)\*(C'\fR
.Sp
rc_buf_optimal_sz
\&\f(CW\*(C`(bufsize * 1000 / vb * 5 / 6)\*(C'\fR
.IP "\fBrc_init_occupancy, vb\fR" 4
.IX Item "rc_init_occupancy, vb"
rc_buf_initial_sz
\&\f(CW\*(C`(rc_init_occupancy * 1000 / vb)\*(C'\fR
.IP "\fBrc_buffer_aggressivity\fR" 4
.IX Item "rc_buffer_aggressivity"
rc_undershoot_pct
.IP "\fBskip_threshold\fR" 4
.IX Item "skip_threshold"
rc_dropframe_thresh
.IP "\fBqcomp\fR" 4
.IX Item "qcomp"
rc_2pass_vbr_bias_pct
.IP "\fBmaxrate, vb\fR" 4
.IX Item "maxrate, vb"
rc_2pass_vbr_maxsection_pct
\&\f(CW\*(C`(maxrate * 100 / vb)\*(C'\fR
.IP "\fBminrate, vb\fR" 4
.IX Item "minrate, vb"
rc_2pass_vbr_minsection_pct
\&\f(CW\*(C`(minrate * 100 / vb)\*(C'\fR
.IP "\fBminrate, maxrate, vb\fR" 4
.IX Item "minrate, maxrate, vb"
\&\f(CW\*(C`VPX_CBR\*(C'\fR
\&\f(CW\*(C`(minrate == maxrate == vb)\*(C'\fR
.IP "\fBcrf\fR" 4
.IX Item "crf"
\&\f(CW\*(C`VPX_CQ\*(C'\fR, \f(CW\*(C`VP8E_SET_CQ_LEVEL\*(C'\fR
.IP "\fBquality\fR" 4
.IX Item "quality"
.RS 4
.PD 0
.IP "\fIbest\fR" 4
.IX Item "best"
.PD
\&\f(CW\*(C`VPX_DL_BEST_QUALITY\*(C'\fR
.IP "\fIgood\fR" 4
.IX Item "good"
\&\f(CW\*(C`VPX_DL_GOOD_QUALITY\*(C'\fR
.IP "\fIrealtime\fR" 4
.IX Item "realtime"
\&\f(CW\*(C`VPX_DL_REALTIME\*(C'\fR
.RE
.RS 4
.RE
.IP "\fBspeed\fR" 4
.IX Item "speed"
\&\f(CW\*(C`VP8E_SET_CPUUSED\*(C'\fR
.IP "\fBnr\fR" 4
.IX Item "nr"
\&\f(CW\*(C`VP8E_SET_NOISE_SENSITIVITY\*(C'\fR
.IP "\fBmb_threshold\fR" 4
.IX Item "mb_threshold"
\&\f(CW\*(C`VP8E_SET_STATIC_THRESHOLD\*(C'\fR
.IP "\fBslices\fR" 4
.IX Item "slices"
\&\f(CW\*(C`VP8E_SET_TOKEN_PARTITIONS\*(C'\fR
.IP "\fBmax-intra-rate\fR" 4
.IX Item "max-intra-rate"
\&\f(CW\*(C`VP8E_SET_MAX_INTRA_BITRATE_PCT\*(C'\fR
.IP "\fBforce_key_frames\fR" 4
.IX Item "force_key_frames"
\&\f(CW\*(C`VPX_EFLAG_FORCE_KF\*(C'\fR
.IP "\fBAlternate reference frame related\fR" 4
.IX Item "Alternate reference frame related"
.RS 4
.PD 0
.IP "\fBvp8flags altref\fR" 4
.IX Item "vp8flags altref"
.PD
\&\f(CW\*(C`VP8E_SET_ENABLEAUTOALTREF\*(C'\fR
.IP "\fIarnr_max_frames\fR" 4
.IX Item "arnr_max_frames"
\&\f(CW\*(C`VP8E_SET_ARNR_MAXFRAMES\*(C'\fR
.IP "\fIarnr_type\fR" 4
.IX Item "arnr_type"
\&\f(CW\*(C`VP8E_SET_ARNR_TYPE\*(C'\fR
.IP "\fIarnr_strength\fR" 4
.IX Item "arnr_strength"
\&\f(CW\*(C`VP8E_SET_ARNR_STRENGTH\*(C'\fR
.IP "\fIrc_lookahead\fR" 4
.IX Item "rc_lookahead"
g_lag_in_frames
.RE
.RS 4
.RE
.IP "\fBvp8flags error_resilient\fR" 4
.IX Item "vp8flags error_resilient"
g_error_resilient
.PP
For more information about libvpx see:
<\fBhttp://www.webmproject.org/\fR>
.Sh "libx264"
.IX Subsection "libx264"
x264 H.264/MPEG\-4 \s-1AVC\s0 encoder wrapper.
.PP
This encoder requires the presence of the libx264 headers and library
during configuration. You need to explicitly configure the build with
\&\f(CW\*(C`\-\-enable\-libx264\*(C'\fR.
.PP
libx264 supports an impressive number of features, including 8x8 and
4x4 adaptive spatial transform, adaptive B\-frame placement, \s-1CAVLC/CABAC\s0
entropy coding, interlacing (\s-1MBAFF\s0), lossless mode, psy optimizations
for detail retention (adaptive quantization, psy\-RD, psy\-trellis).
.PP
Many libx264 encoder options are mapped to FFmpeg global codec
options, while unique encoder options are provided through private
options. Additionally the \fBx264opts\fR and \fBx264\-params\fR
private options allows to pass a list of key=value tuples as accepted
by the libx264 \f(CW\*(C`x264_param_parse\*(C'\fR function.
.PP
The x264 project website is at
<\fBhttp://www.videolan.org/developers/x264.html\fR>.
.PP
\fIOptions\fR
.IX Subsection "Options"
.PP
The following options are supported by the libx264 wrapper. The
\&\fBx264\fR\-equivalent options or values are listed in parentheses
for easy migration.
.PP
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.
.PP
To get a more accurate and extensive documentation of the libx264
options, invoke the command \fBx264 \-\-full\-help\fR or consult
the libx264 documentation.
.IP "\fBb (\fR\fIbitrate\fR\fB)\fR" 4
.IX Item "b (bitrate)"
Set bitrate in bits/s. Note that FFmpeg's \fBb\fR option is
expressed in bits/s, while \fBx264\fR's \fBbitrate\fR is in
kilobits/s.
.IP "\fBbf (\fR\fIbframes\fR\fB)\fR" 4
.IX Item "bf (bframes)"
.PD 0
.IP "\fBg (\fR\fIkeyint\fR\fB)\fR" 4
.IX Item "g (keyint)"
.IP "\fBqmax (\fR\fIqpmax\fR\fB)\fR" 4
.IX Item "qmax (qpmax)"
.IP "\fBqmin (\fR\fIqpmin\fR\fB)\fR" 4
.IX Item "qmin (qpmin)"
.IP "\fBqdiff (\fR\fIqpstep\fR\fB)\fR" 4
.IX Item "qdiff (qpstep)"
.IP "\fBqblur (\fR\fIqblur\fR\fB)\fR" 4
.IX Item "qblur (qblur)"
.IP "\fBqcomp (\fR\fIqcomp\fR\fB)\fR" 4
.IX Item "qcomp (qcomp)"
.IP "\fBrefs (\fR\fIref\fR\fB)\fR" 4
.IX Item "refs (ref)"
.IP "\fBsc_threshold (\fR\fIscenecut\fR\fB)\fR" 4
.IX Item "sc_threshold (scenecut)"
.IP "\fBtrellis (\fR\fItrellis\fR\fB)\fR" 4
.IX Item "trellis (trellis)"
.IP "\fBnr  (\fR\fInr\fR\fB)\fR" 4
.IX Item "nr  (nr)"
.IP "\fBme_range (\fR\fImerange\fR\fB)\fR" 4
.IX Item "me_range (merange)"
.IP "\fBme_method (\fR\fIme\fR\fB)\fR" 4
.IX Item "me_method (me)"
.PD
Set motion estimation method. Possible values in the decreasing order
of speed:
.RS 4
.IP "\fBdia (\fR\fIdia\fR\fB)\fR" 4
.IX Item "dia (dia)"
.PD 0
.IP "\fBepzs (\fR\fIdia\fR\fB)\fR" 4
.IX Item "epzs (dia)"
.PD
Diamond search with radius 1 (fastest). \fBepzs\fR is an alias for
\&\fBdia\fR.
.IP "\fBhex (\fR\fIhex\fR\fB)\fR" 4
.IX Item "hex (hex)"
Hexagonal search with radius 2.
.IP "\fBumh (\fR\fIumh\fR\fB)\fR" 4
.IX Item "umh (umh)"
Uneven multi-hexagon search.
.IP "\fBesa (\fR\fIesa\fR\fB)\fR" 4
.IX Item "esa (esa)"
Exhaustive search.
.IP "\fBtesa (\fR\fItesa\fR\fB)\fR" 4
.IX Item "tesa (tesa)"
Hadamard exhaustive search (slowest).
.RE
.RS 4
.RE
.IP "\fBsubq (\fR\fIsubme\fR\fB)\fR" 4
.IX Item "subq (subme)"
.PD 0
.IP "\fBb_strategy (\fR\fIb\-adapt\fR\fB)\fR" 4
.IX Item "b_strategy (b-adapt)"
.IP "\fBkeyint_min (\fR\fImin-keyint\fR\fB)\fR" 4
.IX Item "keyint_min (min-keyint)"
.IP "\fBcoder\fR" 4
.IX Item "coder"
.PD
Set entropy encoder. Possible values:
.RS 4
.IP "\fBac\fR" 4
.IX Item "ac"
Enable \s-1CABAC\s0.
.IP "\fBvlc\fR" 4
.IX Item "vlc"
Enable \s-1CAVLC\s0 and disable \s-1CABAC\s0. It generates the same effect as
\&\fBx264\fR's \fB\-\-no\-cabac\fR option.
.RE
.RS 4
.RE
.IP "\fBcmp\fR" 4
.IX Item "cmp"
Set full pixel motion estimation comparation algorithm. Possible values:
.RS 4
.IP "\fBchroma\fR" 4
.IX Item "chroma"
Enable chroma in motion estimation.
.IP "\fBsad\fR" 4
.IX Item "sad"
Ignore chroma in motion estimation. It generates the same effect as
\&\fBx264\fR's \fB\-\-no\-chroma\-me\fR option.
.RE
.RS 4
.RE
.IP "\fBthreads (\fR\fIthreads\fR\fB)\fR" 4
.IX Item "threads (threads)"
.PD 0
.IP "\fBthread_type\fR" 4
.IX Item "thread_type"
.PD
Set multithreading technique. Possible values:
.RS 4
.IP "\fBslice\fR" 4
.IX Item "slice"
Slice-based multithreading. It generates the same effect as
\&\fBx264\fR's \fB\-\-sliced\-threads\fR option.
.IP "\fBframe\fR" 4
.IX Item "frame"
Frame-based multithreading.
.RE
.RS 4
.RE
.IP "\fBflags\fR" 4
.IX Item "flags"
Set encoding flags. It can be used to disable closed \s-1GOP\s0 and enable
open \s-1GOP\s0 by setting it to \f(CW\*(C`\-cgop\*(C'\fR. The result is similar to
the behavior of \fBx264\fR's \fB\-\-open\-gop\fR option.
.IP "\fBrc_init_occupancy (\fR\fIvbv-init\fR\fB)\fR" 4
.IX Item "rc_init_occupancy (vbv-init)"
.PD 0
.IP "\fBpreset (\fR\fIpreset\fR\fB)\fR" 4
.IX Item "preset (preset)"
.PD
Set the encoding preset.
.IP "\fBtune (\fR\fItune\fR\fB)\fR" 4
.IX Item "tune (tune)"
Set tuning of the encoding params.
.IP "\fBprofile (\fR\fIprofile\fR\fB)\fR" 4
.IX Item "profile (profile)"
Set profile restrictions.
.IP "\fBfastfirstpass\fR" 4
.IX Item "fastfirstpass"
Enable fast settings when encoding first pass, when set to 1. When set
to 0, it has the same effect of \fBx264\fR's
\&\fB\-\-slow\-firstpass\fR option.
.IP "\fBcrf (\fR\fIcrf\fR\fB)\fR" 4
.IX Item "crf (crf)"
Set the quality for constant quality mode.
.IP "\fBcrf_max (\fR\fIcrf-max\fR\fB)\fR" 4
.IX Item "crf_max (crf-max)"
In \s-1CRF\s0 mode, prevents \s-1VBV\s0 from lowering quality beyond this point.
.IP "\fBqp (\fR\fIqp\fR\fB)\fR" 4
.IX Item "qp (qp)"
Set constant quantization rate control method parameter.
.IP "\fBaq-mode (\fR\fIaq-mode\fR\fB)\fR" 4
.IX Item "aq-mode (aq-mode)"
Set \s-1AQ\s0 method. Possible values:
.RS 4
.IP "\fBnone (\fR\fI0\fR\fB)\fR" 4
.IX Item "none (0)"
Disabled.
.IP "\fBvariance (\fR\fI1\fR\fB)\fR" 4
.IX Item "variance (1)"
Variance \s-1AQ\s0 (complexity mask).
.IP "\fBautovariance (\fR\fI2\fR\fB)\fR" 4
.IX Item "autovariance (2)"
Auto-variance \s-1AQ\s0 (experimental).
.RE
.RS 4
.RE
.IP "\fBaq-strength (\fR\fIaq-strength\fR\fB)\fR" 4
.IX Item "aq-strength (aq-strength)"
Set \s-1AQ\s0 strength, reduce blocking and blurring in flat and textured areas.
.IP "\fBpsy\fR" 4
.IX Item "psy"
Use psychovisual optimizations when set to 1. When set to 0, it has the
same effect as \fBx264\fR's \fB\-\-no\-psy\fR option.
.IP "\fBpsy-rd  (\fR\fIpsy-rd\fR\fB)\fR" 4
.IX Item "psy-rd  (psy-rd)"
Set strength of psychovisual optimization, in
\&\fIpsy-rd\fR:\fIpsy-trellis\fR format.
.IP "\fBrc-lookahead (\fR\fIrc-lookahead\fR\fB)\fR" 4
.IX Item "rc-lookahead (rc-lookahead)"
Set number of frames to look ahead for frametype and ratecontrol.
.IP "\fBweightb\fR" 4
.IX Item "weightb"
Enable weighted prediction for B\-frames when set to 1. When set to 0,
it has the same effect as \fBx264\fR's \fB\-\-no\-weightb\fR option.
.IP "\fBweightp (\fR\fIweightp\fR\fB)\fR" 4
.IX Item "weightp (weightp)"
Set weighted prediction method for P\-frames. Possible values:
.RS 4
.IP "\fBnone (\fR\fI0\fR\fB)\fR" 4
.IX Item "none (0)"
Disabled
.IP "\fBsimple (\fR\fI1\fR\fB)\fR" 4
.IX Item "simple (1)"
Enable only weighted refs
.IP "\fBsmart (\fR\fI2\fR\fB)\fR" 4
.IX Item "smart (2)"
Enable both weighted refs and duplicates
.RE
.RS 4
.RE
.IP "\fBssim (\fR\fIssim\fR\fB)\fR" 4
.IX Item "ssim (ssim)"
Enable calculation and printing \s-1SSIM\s0 stats after the encoding.
.IP "\fBintra-refresh (\fR\fIintra-refresh\fR\fB)\fR" 4
.IX Item "intra-refresh (intra-refresh)"
Enable the use of Periodic Intra Refresh instead of \s-1IDR\s0 frames when set
to 1.
.IP "\fBbluray-compat (\fR\fIbluray-compat\fR\fB)\fR" 4
.IX Item "bluray-compat (bluray-compat)"
Configure the encoder to be compatible with the bluray standard.
It is a shorthand for setting \*(L"bluray\-compat=1 force\-cfr=1\*(R".
.IP "\fBb\-bias (\fR\fIb\-bias\fR\fB)\fR" 4
.IX Item "b-bias (b-bias)"
Set the influence on how often B\-frames are used.
.IP "\fBb\-pyramid (\fR\fIb\-pyramid\fR\fB)\fR" 4
.IX Item "b-pyramid (b-pyramid)"
Set method for keeping of some B\-frames as references. Possible values:
.RS 4
.IP "\fBnone (\fR\fInone\fR\fB)\fR" 4
.IX Item "none (none)"
Disabled.
.IP "\fBstrict (\fR\fIstrict\fR\fB)\fR" 4
.IX Item "strict (strict)"
Strictly hierarchical pyramid.
.IP "\fBnormal (\fR\fInormal\fR\fB)\fR" 4
.IX Item "normal (normal)"
Non-strict (not Blu-ray compatible).
.RE
.RS 4
.RE
.IP "\fBmixed-refs\fR" 4
.IX Item "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 \fBx264\fR's \fB\-\-no\-mixed\-refs\fR option.
.IP "\fB8x8dct\fR" 4
.IX Item "8x8dct"
Enable adaptive spatial transform (high profile 8x8 transform)
when set to 1. When set to 0, it has the same effect as
\&\fBx264\fR's \fB\-\-no\-8x8dct\fR option.
.IP "\fBfast-pskip\fR" 4
.IX Item "fast-pskip"
Enable early \s-1SKIP\s0 detection on P\-frames when set to 1. When set
to 0, it has the same effect as \fBx264\fR's
\&\fB\-\-no\-fast\-pskip\fR option.
.IP "\fBaud (\fR\fIaud\fR\fB)\fR" 4
.IX Item "aud (aud)"
Enable use of access unit delimiters when set to 1.
.IP "\fBmbtree\fR" 4
.IX Item "mbtree"
Enable use macroblock tree ratecontrol when set to 1. When set
to 0, it has the same effect as \fBx264\fR's
\&\fB\-\-no\-mbtree\fR option.
.IP "\fBdeblock (\fR\fIdeblock\fR\fB)\fR" 4
.IX Item "deblock (deblock)"
Set loop filter parameters, in \fIalpha\fR:\fIbeta\fR form.
.IP "\fBcplxblur (\fR\fIcplxblur\fR\fB)\fR" 4
.IX Item "cplxblur (cplxblur)"
Set fluctuations reduction in \s-1QP\s0 (before curve compression).
.IP "\fBpartitions (\fR\fIpartitions\fR\fB)\fR" 4
.IX Item "partitions (partitions)"
Set partitions to consider as a comma-separated list of. Possible
values in the list:
.RS 4
.IP "\fBp8x8\fR" 4
.IX Item "p8x8"
8x8 P\-frame partition.
.IP "\fBp4x4\fR" 4
.IX Item "p4x4"
4x4 P\-frame partition.
.IP "\fBb8x8\fR" 4
.IX Item "b8x8"
4x4 B\-frame partition.
.IP "\fBi8x8\fR" 4
.IX Item "i8x8"
8x8 I\-frame partition.
.IP "\fBi4x4\fR" 4
.IX Item "i4x4"
4x4 I\-frame partition.
(Enabling \fBp4x4\fR requires \fBp8x8\fR to be enabled. Enabling
\&\fBi8x8\fR requires adaptive spatial transform (\fB8x8dct\fR
option) to be enabled.)
.IP "\fBnone (\fR\fInone\fR\fB)\fR" 4
.IX Item "none (none)"
Do not consider any partitions.
.IP "\fBall (\fR\fIall\fR\fB)\fR" 4
.IX Item "all (all)"
Consider every partition.
.RE
.RS 4
.RE
.IP "\fBdirect-pred (\fR\fIdirect\fR\fB)\fR" 4
.IX Item "direct-pred (direct)"
Set direct \s-1MV\s0 prediction mode. Possible values:
.RS 4
.IP "\fBnone (\fR\fInone\fR\fB)\fR" 4
.IX Item "none (none)"
Disable \s-1MV\s0 prediction.
.IP "\fBspatial (\fR\fIspatial\fR\fB)\fR" 4
.IX Item "spatial (spatial)"
Enable spatial predicting.
.IP "\fBtemporal (\fR\fItemporal\fR\fB)\fR" 4
.IX Item "temporal (temporal)"
Enable temporal predicting.
.IP "\fBauto (\fR\fIauto\fR\fB)\fR" 4
.IX Item "auto (auto)"
Automatically decided.
.RE
.RS 4
.RE
.IP "\fBslice-max-size (\fR\fIslice-max-size\fR\fB)\fR" 4
.IX Item "slice-max-size (slice-max-size)"
Set the limit of the size of each slice in bytes. If not specified
but \s-1RTP\s0 payload size (\fBps\fR) is specified, that is used.
.IP "\fBstats (\fR\fIstats\fR\fB)\fR" 4
.IX Item "stats (stats)"
Set the file name for multi-pass stats.
.IP "\fBnal-hrd (\fR\fInal-hrd\fR\fB)\fR" 4
.IX Item "nal-hrd (nal-hrd)"
Set signal \s-1HRD\s0 information (requires \fBvbv-bufsize\fR to be set).
Possible values:
.RS 4
.IP "\fBnone (\fR\fInone\fR\fB)\fR" 4
.IX Item "none (none)"
Disable \s-1HRD\s0 information signaling.
.IP "\fBvbr (\fR\fIvbr\fR\fB)\fR" 4
.IX Item "vbr (vbr)"
Variable bit rate.
.IP "\fBcbr (\fR\fIcbr\fR\fB)\fR" 4
.IX Item "cbr (cbr)"
Constant bit rate (not allowed in \s-1MP4\s0 container).
.RE
.RS 4
.RE
.IP "\fBx264opts (N.A.)\fR" 4
.IX Item "x264opts (N.A.)"
Set any x264 option, see \fBx264 \-\-fullhelp\fR for a list.
.Sp
Argument is a list of \fIkey\fR=\fIvalue\fR couples separated by
\&\*(L":\*(R". In \fIfilter\fR and \fIpsy-rd\fR options that use \*(L":\*(R" as a separator
themselves, use \*(L",\*(R" instead. They accept it as well since long ago but this
is kept undocumented for some reason.
.Sp
For example to specify libx264 encoding options with \fBffmpeg\fR:
.Sp
.Vb 1
\&        ffmpeg -i foo.mpg -vcodec libx264 -x264opts keyint=123:min-keyint=20 -an out.mkv
.Ve
.IP "\fBx264\-params (N.A.)\fR" 4
.IX Item "x264-params (N.A.)"
Override the x264 configuration using a :\-separated list of key=value
parameters.
.Sp
This option is functionally the same as the \fBx264opts\fR, but is
duplicated for compability with the Libav fork.
.Sp
For example to specify libx264 encoding options with \fBffmpeg\fR:
.Sp
.Vb 3
\&        ffmpeg -i INPUT -c:v libx264 -x264-params level=30:bframes=0:weightp=0:\e
\&        cabac=0:ref=1:vbv-maxrate=768:vbv-bufsize=2000:analyse=all:me=umh:\e
\&        no-fast-pskip=1:subq=6:8x8dct=0:trellis=0 OUTPUT
.Ve
.PP
Encoding ffpresets for common usages are provided so they can be used with the
general presets system (e.g. passing the \fBpre\fR option).
.Sh "libxvid"
.IX Subsection "libxvid"
Xvid \s-1MPEG\-4\s0 Part 2 encoder wrapper.
.PP
This encoder requires the presence of the libxvidcore headers and library
during configuration. You need to explicitly configure the build with
\&\f(CW\*(C`\-\-enable\-libxvid \-\-enable\-gpl\*(C'\fR.
.PP
The native \f(CW\*(C`mpeg4\*(C'\fR encoder supports the \s-1MPEG\-4\s0 Part 2 format, so
users can encode to this format without this library.
.PP
\fIOptions\fR
.IX Subsection "Options"
.PP
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.
.IP "\fBb\fR" 4
.IX Item "b"
.PD 0
.IP "\fBg\fR" 4
.IX Item "g"
.IP "\fBqmin\fR" 4
.IX Item "qmin"
.IP "\fBqmax\fR" 4
.IX Item "qmax"
.IP "\fBmpeg_quant\fR" 4
.IX Item "mpeg_quant"
.IP "\fBthreads\fR" 4
.IX Item "threads"
.IP "\fBbf\fR" 4
.IX Item "bf"
.IP "\fBb_qfactor\fR" 4
.IX Item "b_qfactor"
.IP "\fBb_qoffset\fR" 4
.IX Item "b_qoffset"
.IP "\fBflags\fR" 4
.IX Item "flags"
.PD
Set specific encoding flags. Possible values:
.RS 4
.IP "\fBmv4\fR" 4
.IX Item "mv4"
Use four motion vector by macroblock.
.IP "\fBaic\fR" 4
.IX Item "aic"
Enable high quality \s-1AC\s0 prediction.
.IP "\fBgray\fR" 4
.IX Item "gray"
Only encode grayscale.
.IP "\fBgmc\fR" 4
.IX Item "gmc"
Enable the use of global motion compensation (\s-1GMC\s0).
.IP "\fBqpel\fR" 4
.IX Item "qpel"
Enable quarter-pixel motion compensation.
.IP "\fBcgop\fR" 4
.IX Item "cgop"
Enable closed \s-1GOP\s0.
.IP "\fBglobal_header\fR" 4
.IX Item "global_header"
Place global headers in extradata instead of every keyframe.
.RE
.RS 4
.RE
.IP "\fBtrellis\fR" 4
.IX Item "trellis"
.PD 0
.IP "\fBme_method\fR" 4
.IX Item "me_method"
.PD
Set motion estimation method. Possible values in decreasing order of
speed and increasing order of quality:
.RS 4
.IP "\fBzero\fR" 4
.IX Item "zero"
Use no motion estimation (default).
.IP "\fBphods\fR" 4
.IX Item "phods"
.PD 0
.IP "\fBx1\fR" 4
.IX Item "x1"
.IP "\fBlog\fR" 4
.IX Item "log"
.PD
Enable advanced diamond zonal search for 16x16 blocks and half-pixel
refinement for 16x16 blocks. \fBx1\fR and \fBlog\fR are aliases for
\&\fBphods\fR.
.IP "\fBepzs\fR" 4
.IX Item "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.
.IP "\fBfull\fR" 4
.IX Item "full"
Enable all of the things described above, plus extended 16x16 and 8x8
blocks search.
.RE
.RS 4
.RE
.IP "\fBmbd\fR" 4
.IX Item "mbd"
Set macroblock decision algorithm. Possible values in the increasing
order of quality:
.RS 4
.IP "\fBsimple\fR" 4
.IX Item "simple"
Use macroblock comparing function algorithm (default).
.IP "\fBbits\fR" 4
.IX Item "bits"
Enable rate distortion-based half pixel and quarter pixel refinement for
16x16 blocks.
.IP "\fBrd\fR" 4
.IX Item "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.
.RE
.RS 4
.RE
.IP "\fBlumi_aq\fR" 4
.IX Item "lumi_aq"
Enable lumi masking adaptive quantization when set to 1. Default is 0
(disabled).
.IP "\fBvariance_aq\fR" 4
.IX Item "variance_aq"
Enable variance adaptive quantization when set to 1. Default is 0
(disabled).
.Sp
When combined with \fBlumi_aq\fR, 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.
.IP "\fBssim\fR" 4
.IX Item "ssim"
Set structural similarity (\s-1SSIM\s0) displaying method. Possible values:
.RS 4
.IP "\fBoff\fR" 4
.IX Item "off"
Disable displaying of \s-1SSIM\s0 information.
.IP "\fBavg\fR" 4
.IX Item "avg"
Output average \s-1SSIM\s0 at the end of encoding to stdout. The format of
showing the average \s-1SSIM\s0 is:
.Sp
.Vb 1
\&        Average SSIM: %f
.Ve
.Sp
For users who are not familiar with C, \f(CW%f\fR means a float number, or
a decimal (e.g. 0.939232).
.IP "\fBframe\fR" 4
.IX Item "frame"
Output both per-frame \s-1SSIM\s0 data during encoding and average \s-1SSIM\s0 at
the end of encoding to stdout. The format of per-frame information
is:
.Sp
.Vb 1
\&               SSIM: avg: %1.3f min: %1.3f max: %1.3f
.Ve
.Sp
For users who are not familiar with C, \f(CW%1\fR.3f means a float number
rounded to 3 digits after the dot (e.g. 0.932).
.RE
.RS 4
.RE
.IP "\fBssim_acc\fR" 4
.IX Item "ssim_acc"
Set \s-1SSIM\s0 accuracy. Valid options are integers within the range of
0\-4, while 0 gives the most accurate result and 4 computes the
fastest.
.Sh "png"
.IX Subsection "png"
\&\s-1PNG\s0 image encoder.
.PP
\fIPrivate options\fR
.IX Subsection "Private options"
.IP "\fBdpi\fR \fIinteger\fR" 4
.IX Item "dpi integer"
Set physical density of pixels, in dots per inch, unset by default
.IP "\fBdpm\fR \fIinteger\fR" 4
.IX Item "dpm integer"
Set physical density of pixels, in dots per meter, unset by default
.Sh "ProRes"
.IX Subsection "ProRes"
Apple ProRes encoder.
.PP
FFmpeg contains 2 ProRes encoders, the prores-aw and prores-ks encoder.
The used encoder can be choosen with the \f(CW\*(C`\-vcodec\*(C'\fR option.
.PP
\fIPrivate Options for prores-ks\fR
.IX Subsection "Private Options for prores-ks"
.IP "\fBprofile\fR \fIinteger\fR" 4
.IX Item "profile integer"
Select the ProRes profile to encode
.RS 4
.IP "\fBproxy\fR" 4
.IX Item "proxy"
.PD 0
.IP "\fBlt\fR" 4
.IX Item "lt"
.IP "\fBstandard\fR" 4
.IX Item "standard"
.IP "\fBhq\fR" 4
.IX Item "hq"
.IP "\fB4444\fR" 4
.IX Item "4444"
.RE
.RS 4
.RE
.IP "\fBquant_mat\fR \fIinteger\fR" 4
.IX Item "quant_mat integer"
.PD
Select quantization matrix.
.RS 4
.IP "\fBauto\fR" 4
.IX Item "auto"
.PD 0
.IP "\fBdefault\fR" 4
.IX Item "default"
.IP "\fBproxy\fR" 4
.IX Item "proxy"
.IP "\fBlt\fR" 4
.IX Item "lt"
.IP "\fBstandard\fR" 4
.IX Item "standard"
.IP "\fBhq\fR" 4
.IX Item "hq"
.RE
.RS 4
.PD
.Sp
If set to \fIauto\fR, the matrix matching the profile will be picked.
If not set, the matrix providing the highest quality, \fIdefault\fR, will be
picked.
.RE
.IP "\fBbits_per_mb\fR \fIinteger\fR" 4
.IX Item "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.
.IP "\fBmbs_per_slice\fR \fIinteger\fR" 4
.IX Item "mbs_per_slice integer"
Number of macroblocks in each slice (1\-8); the default value (8)
should be good in almost all situations.
.IP "\fBvendor\fR \fIstring\fR" 4
.IX Item "vendor string"
Override the 4\-byte vendor \s-1ID\s0.
A custom vendor \s-1ID\s0 like \fIapl0\fR would claim the stream was produced by
the Apple encoder.
.IP "\fBalpha_bits\fR \fIinteger\fR" 4
.IX Item "alpha_bits integer"
Specify number of bits for alpha component.
Possible values are \fI0\fR, \fI8\fR and \fI16\fR.
Use \fI0\fR to disable alpha plane coding.
.PP
\fISpeed considerations\fR
.IX Subsection "Speed considerations"
.PP
In the default mode of operation the encoder has to honor frame constraints
(i.e. not produc 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.
.PP
Setting a higher \fBbits_per_mb\fR limit will improve the speed.
.PP
For the fastest encoding speed set the \fBqscale\fR parameter (4 is the
recommended value) and do not set a size constraint.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\fIffmpeg\fR\|(1), \fIffplay\fR\|(1), \fIffprobe\fR\|(1), \fIffserver\fR\|(1), \fIlibavcodec\fR\|(3)
.SH "AUTHORS"
.IX Header "AUTHORS"
The FFmpeg developers.
.PP
For details about the authorship, see the Git history of the project
(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
\&\fBgit log\fR in the FFmpeg source directory, or browsing the
online repository at <\fBhttp://source.ffmpeg.org\fR>.
.PP
Maintainers for the specific components are listed in the file
\&\fI\s-1MAINTAINERS\s0\fR in the source code tree.