Provided by: ffmpeg_3.4.11-0ubuntu0.1_amd64 bug

NAME

       ffmpeg-codecs - FFmpeg codecs

DESCRIPTION

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

CODEC OPTIONS

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

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

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

       The list of supported options follow:

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

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

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

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

           Possible values:

           mv4 Use four motion vector by macroblock (mpeg4).

           qpel
               Use 1/4 pel motion compensation.

           loop
               Use loop filter.

           qscale
               Use fixed qscale.

           gmc Use gmc.

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

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

           pass2
               Use internal 2pass ratecontrol in second pass mode.

           gray
               Only decode/encode grayscale.

           emu_edge
               Do not draw edges.

           psnr
               Set error[?] variables during encoding.

           truncated
           naq Normalize adaptive quantization.

           ildct
               Use interlaced DCT.

           low_delay
               Force low delay.

           global_header
               Place global headers in extradata instead of every keyframe.

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

           aic Apply H263 advanced intra coding / mpeg4 ac prediction.

           cbp Deprecated, use mpegvideo private options instead.

           qprd
               Deprecated, use mpegvideo private options instead.

           ilme
               Apply interlaced motion estimation.

           cgop
               Use closed gop.

       me_method integer (encoding,video)
           Set motion estimation method.

           Possible values:

           zero
               zero motion estimation (fastest)

           full
               full motion estimation (slowest)

           epzs
               EPZS motion estimation (default)

           esa esa motion estimation (alias for full)

           tesa
               tesa motion estimation

           dia dia motion estimation (alias for epzs)

           log log motion estimation

           phods
               phods motion estimation

           x1  X1 motion estimation

           hex hex motion estimation

           umh umh motion estimation

           iter
               iter motion estimation

       extradata_size integer
           Set extradata size.

       time_base rational number
           Set codec time base.

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

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

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

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

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

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

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

       frame_number integer
           Set the frame number.

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

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

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

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

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

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

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

           Default value is 0.

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

       rc_strategy integer (encoding,video)
           Set ratecontrol method.

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

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

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

           Possible values:

           autodetect
           old_msmpeg4
               some old lavc generated msmpeg4v3 files (no autodetection)

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

           ump4
               (autodetected if fourcc==UMP4)

           no_padding
               padding bug (autodetected)

           amv
           ac_vlc
               illegal vlc bug (autodetected per fourcc)

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

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

           edge
               edge padding bug (autodetected per fourcc/version)

           hpel_chroma
           dc_clip
           ms  Workaround various bugs in microsoft broken decoders.

           trunc
               trancated frames

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

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

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

           Possible values:

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

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

           normal
           unofficial
               allow unofficial extensions

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

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

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

           Possible values:

           crccheck
               verify embedded CRCs

           bitstream
               detect bitstream specification deviations

           buffer
               detect improper bitstream length

           explode
               abort decoding on minor error detection

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

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

           compliant
               consider all spec non compliancies as errors

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

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

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

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

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

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

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

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

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

       rc_buf_aggressivity float (encoding,video)
           Currently useless.

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

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

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

       dct integer (encoding,video)
           Set DCT algorithm.

           Possible values:

           auto
               autoselect a good one (default)

           fastint
               fast integer

           int accurate integer

           mmx
           altivec
           faan
               floating point AAN DCT

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

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

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

       p_mask float (encoding,video)
           Set inter masking.

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

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

           Possible values:

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

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

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

           Possible values:

           guess_mvs
               iterative motion vector (MV) search (slow)

           deblock
               use strong deblock filter for damaged MBs

           favor_inter
               favor predicting from the previous frame instead of the current

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

           Possible values:

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

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

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

           Possible values:

           pict
               picture info

           rc  rate control

           bitstream
           mb_type
               macroblock (MB) type

           qp  per-block quantization parameter (QP)

           mv  motion vector

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

           skip
           startcode
           pts
           er  error recognition

           mmco
               memory management control operations (H.264)

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

           vis_mb_type
               visualize block types

           buffers
               picture buffer allocations

           thread_ops
               threading operations

           nomc
               skip motion compensation

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

           This option is deprecated, see the codecview filter instead.

           Possible values:

           pf  forward predicted MVs of P-frames

           bf  forward predicted MVs of B-frames

           bb  backward predicted MVs of B-frames

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

           Possible values:

           sad sum of absolute differences, fast (default)

           sse sum of squared errors

           satd
               sum of absolute Hadamard transformed differences

           dct sum of absolute DCT transformed differences

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

           bit number of bits needed for the block

           rd  rate distortion optimal, slow

           zero
               0

           vsad
               sum of absolute vertical differences

           vsse
               sum of squared vertical differences

           nsse
               noise preserving sum of squared differences

           w53 5/3 wavelet, only used in snow

           w97 9/7 wavelet, only used in snow

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

           Possible values:

           sad sum of absolute differences, fast (default)

           sse sum of squared errors

           satd
               sum of absolute Hadamard transformed differences

           dct sum of absolute DCT transformed differences

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

           bit number of bits needed for the block

           rd  rate distortion optimal, slow

           zero
               0

           vsad
               sum of absolute vertical differences

           vsse
               sum of squared vertical differences

           nsse
               noise preserving sum of squared differences

           w53 5/3 wavelet, only used in snow

           w97 9/7 wavelet, only used in snow

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

           Possible values:

           sad sum of absolute differences, fast (default)

           sse sum of squared errors

           satd
               sum of absolute Hadamard transformed differences

           dct sum of absolute DCT transformed differences

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

           bit number of bits needed for the block

           rd  rate distortion optimal, slow

           zero
               0

           vsad
               sum of absolute vertical differences

           vsse
               sum of squared vertical differences

           nsse
               noise preserving sum of squared differences

           w53 5/3 wavelet, only used in snow

           w97 9/7 wavelet, only used in snow

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

           Possible values:

           sad sum of absolute differences, fast (default)

           sse sum of squared errors

           satd
               sum of absolute Hadamard transformed differences

           dct sum of absolute DCT transformed differences

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

           bit number of bits needed for the block

           rd  rate distortion optimal, slow

           zero
               0

           vsad
               sum of absolute vertical differences

           vsse
               sum of squared vertical differences

           nsse
               noise preserving sum of squared differences

           w53 5/3 wavelet, only used in snow

           w97 9/7 wavelet, only used in snow

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

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

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

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

           Possible values:

           sad sum of absolute differences, fast (default)

           sse sum of squared errors

           satd
               sum of absolute Hadamard transformed differences

           dct sum of absolute DCT transformed differences

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

           bit number of bits needed for the block

           rd  rate distortion optimal, slow

           zero
               0

           vsad
               sum of absolute vertical differences

           vsse
               sum of squared vertical differences

           nsse
               noise preserving sum of squared differences

           w53 5/3 wavelet, only used in snow

           w97 9/7 wavelet, only used in snow

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

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

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

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

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

       color_table_id integer
       global_quality integer (encoding,audio,video)
       coder integer (encoding,video)
           Possible values:

           vlc variable length coder / huffman coder

           ac  arithmetic coder

           raw raw (no encoding)

           rle run-length coder

           deflate
               deflate-based coder

       context integer (encoding,video)
           Set context model.

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

           Possible values:

           simple
               use mbcmp (default)

           bits
               use fewest bits

           rd  use best rate distortion

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

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

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

       nr integer (encoding,video)
           Set noise reduction.

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

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

           fast
               Allow non spec compliant speedup tricks.

           sgop
               Deprecated, use mpegvideo private options instead.

           noout
               Skip bitstream encoding.

           ignorecrop
               Ignore cropping information from sps.

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

           chunks
               Frame data might be split into multiple chunks.

           showall
               Show all frames before the first keyframe.

           skiprd
               Deprecated, use mpegvideo private options instead.

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

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

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

           Possible values:

           auto, 0
               automatically select the number of threads to set

           Default value is auto.

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

       mb_threshold integer (encoding,video)
           Set macroblock threshold.

       dc integer (encoding,video)
           Set intra_dc_precision.

       nssew integer (encoding,video)
           Set nsse weight.

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

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

       profile integer (encoding,audio,video)
           Possible values:

           unknown
           aac_main
           aac_low
           aac_ssr
           aac_ltp
           aac_he
           aac_he_v2
           aac_ld
           aac_eld
           mpeg2_aac_low
           mpeg2_aac_he
           mpeg4_sp
           mpeg4_core
           mpeg4_main
           mpeg4_asp
           dts
           dts_es
           dts_96_24
           dts_hd_hra
           dts_hd_ma
       level integer (encoding,audio,video)
           Possible values:

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

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

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

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

       skipcmp integer (encoding,video)
           Set frame skip compare function.

           Possible values:

           sad sum of absolute differences, fast (default)

           sse sum of squared errors

           satd
               sum of absolute Hadamard transformed differences

           dct sum of absolute DCT transformed differences

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

           bit number of bits needed for the block

           rd  rate distortion optimal, slow

           zero
               0

           vsad
               sum of absolute vertical differences

           vsse
               sum of squared vertical differences

           nsse
               noise preserving sum of squared differences

           w53 5/3 wavelet, only used in snow

           w97 9/7 wavelet, only used in snow

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

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

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

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

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

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

           Possible values:

           none
               Discard no frame.

           default
               Discard useless frames like 0-sized frames.

           noref
               Discard all non-reference frames.

           bidir
               Discard all bidirectional frames.

           nokey
               Discard all frames excepts keyframes.

           all Discard all frames.

           Default value is default.

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

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

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

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

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

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

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

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

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

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

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

       request_channel_layout integer (decoding,audio)
           Possible values:

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

           bt709
               BT.709

           bt470m
               BT.470 M

           bt470bg
               BT.470 BG

           smpte170m
               SMPTE 170 M

           smpte240m
               SMPTE 240 M

           film
               Film

           bt2020
               BT.2020

           smpte428
           smpte428_1
               SMPTE ST 428-1

           smpte431
               SMPTE 431-2

           smpte432
               SMPTE 432-1

           jedec-p22
               JEDEC P22

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

           bt709
               BT.709

           gamma22
               BT.470 M

           gamma28
               BT.470 BG

           smpte170m
               SMPTE 170 M

           smpte240m
               SMPTE 240 M

           linear
               Linear

           log
           log100
               Log

           log_sqrt
           log316
               Log square root

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

           bt1361
           bt1361e
               BT.1361

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

           bt2020_10
           bt2020_10bit
               BT.2020 - 10 bit

           bt2020_12
           bt2020_12bit
               BT.2020 - 12 bit

           smpte2084
               SMPTE ST 2084

           smpte428
           smpte428_1
               SMPTE ST 428-1

           arib-std-b67
               ARIB STD-B67

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

           rgb RGB

           bt709
               BT.709

           fcc FCC

           bt470bg
               BT.470 BG

           smpte170m
               SMPTE 170 M

           smpte240m
               SMPTE 240 M

           ycocg
               YCOCG

           bt2020nc
           bt2020_ncl
               BT.2020 NCL

           bt2020c
           bt2020_cl
               BT.2020 CL

           smpte2085
               SMPTE 2085

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

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

           pc
           jpeg
               JPEG (2^n-1)

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

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

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

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

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

           Possible values:

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

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

           frame
               Decode more than one frame at once.

           Default value is slice+frame.

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

           Possible values:

           ma  Main Audio Service

           ef  Effects

           vi  Visually Impaired

           hi  Hearing Impaired

           di  Dialogue

           co  Commentary

           em  Emergency

           vo  Voice Over

           ka  Karaoke

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

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

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

           progressive
               Progressive video

           tt  Interlaced video, top field coded and displayed first

           bb  Interlaced video, bottom field coded and displayed first

           tb  Interlaced video, top coded first, bottom displayed first

           bt  Interlaced video, bottom coded first, top displayed first

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

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

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

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

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

       apply_cropping bool (decoding,video)
           Enable cropping if cropping parameters are multiples of the required alignment for the left and top
           parameters. If the alignment is not met the cropping will be partially applied to maintain alignment.
           Default is 1 (enabled).  Note: The required alignment depends on if "AV_CODEC_FLAG_UNALIGNED" is set
           and the CPU. "AV_CODEC_FLAG_UNALIGNED" cannot be changed from the command line. Also hardware
           decoders will not apply left/top Cropping.

DECODERS

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

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

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

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

VIDEO DECODERS

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

   hevc
       HEVC / H.265 decoder.

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

   rawvideo
       Raw video decoder.

       This decoder decodes rawvideo streams.

       Options

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

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

           0   bottom-field-first is assumed

           1   top-field-first is assumed

AUDIO DECODERS

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

   ac3
       AC-3 audio decoder.

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

       AC-3 Decoder Options

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

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

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

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

   flac
       FLAC audio decoder.

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

       FLAC Decoder options

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

   ffwavesynth
       Internal wave synthesizer.

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

   libcelt
       libcelt decoder wrapper.

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

   libgsm
       libgsm decoder wrapper.

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

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

   libilbc
       libilbc decoder wrapper.

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

       Options

       The following option is supported by the libilbc wrapper.

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

   libopencore-amrnb
       libopencore-amrnb decoder wrapper.

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

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

   libopencore-amrwb
       libopencore-amrwb decoder wrapper.

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

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

   libopus
       libopus decoder wrapper.

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

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

SUBTITLES DECODERS

   dvbsub
       Options

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

           0   Never compute CLUT

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

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

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

       Options

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

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

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

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

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

       Options

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

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

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

       txt_left
           X offset of generated bitmaps, default is 0.

       txt_top
           Y offset of generated bitmaps, default is 0.

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

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

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

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

ENCODERS

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

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

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

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

AUDIO ENCODERS

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

   aac
       Advanced Audio Coding (AAC) encoder.

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

       Options

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

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

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

       aac_coder
           Set AAC encoder coding method. Possible values:

           twoloop
               Two loop searching (TLS) method.

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

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

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

           fast
               Constant quantizer method.

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

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

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

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

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

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

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

       profile
           Sets the encoding profile, possible values:

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

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

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

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

           If this option is unspecified it is set to aac_low.

   ac3 and ac3_fixed
       AC-3 audio encoders.

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

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

       AC-3 Metadata

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

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

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

       Metadata Control Options

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

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

           1   Metadata values can be changed before encoding each frame.

       Downmix Levels

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

           0.707
               Apply -3dB gain

           0.595
               Apply -4.5dB gain (default)

           0.500
               Apply -6dB gain

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

           0.707
               Apply -3dB gain

           0.500
               Apply -6dB gain (default)

           0.000
               Silence Surround Channel(s)

       Audio Production Information

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

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

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

           0
           notindicated
               Not Indicated (default)

           1
           large
               Large Room

           2
           small
               Small Room

       Other Metadata Options

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

           0
           off No Copyright Exists (default)

           1
           on  Copyright Exists

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

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

           0
           notindicated
               Not Indicated (default)

           1
           off Not Dolby Surround Encoded

           2
           on  Dolby Surround Encoded

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

           0
           off Not Original Source

           1
           on  Original Source (default)

       Extended Bitstream Information

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

       Extended Bitstream Information - Part 1

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

           0
           notindicated
               Not Indicated (default)

           1
           ltrt
               Lt/Rt Downmix Preferred

           2
           loro
               Lo/Ro Downmix Preferred

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

           1.414
               Apply +3dB gain

           1.189
               Apply +1.5dB gain

           1.000
               Apply 0dB gain

           0.841
               Apply -1.5dB gain

           0.707
               Apply -3.0dB gain

           0.595
               Apply -4.5dB gain (default)

           0.500
               Apply -6.0dB gain

           0.000
               Silence Center Channel

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

           0.841
               Apply -1.5dB gain

           0.707
               Apply -3.0dB gain

           0.595
               Apply -4.5dB gain

           0.500
               Apply -6.0dB gain (default)

           0.000
               Silence Surround Channel(s)

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

           1.414
               Apply +3dB gain

           1.189
               Apply +1.5dB gain

           1.000
               Apply 0dB gain

           0.841
               Apply -1.5dB gain

           0.707
               Apply -3.0dB gain

           0.595
               Apply -4.5dB gain (default)

           0.500
               Apply -6.0dB gain

           0.000
               Silence Center Channel

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

           0.841
               Apply -1.5dB gain

           0.707
               Apply -3.0dB gain

           0.595
               Apply -4.5dB gain

           0.500
               Apply -6.0dB gain (default)

           0.000
               Silence Surround Channel(s)

       Extended Bitstream Information - Part 2

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

           0
           notindicated
               Not Indicated (default)

           1
           on  Dolby Surround EX Off

           2
           off Dolby Surround EX On

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

           0
           notindicated
               Not Indicated (default)

           1
           on  Dolby Headphone Off

           2
           off Dolby Headphone On

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

           0
           standard
               Standard A/D Converter (default)

           1
           hdcd
               HDCD A/D Converter

       Other AC-3 Encoding Options

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

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

       Floating-Point-Only AC-3 Encoding Options

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

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

           -1
           auto
               Selected by Encoder (default)

           0
           off Disable Channel Coupling

           1
           on  Enable Channel Coupling

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

           -1
           auto
               Selected by Encoder (default)

   flac
       FLAC (Free Lossless Audio Codec) Encoder

       Options

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

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

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

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

       lpc_type
           Sets the first stage LPC algorithm

           none
               LPC is not used

           fixed
               fixed LPC coefficients

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

       min_partition_order
           The minimum partition order

       max_partition_order
           The maximum partition order

       prediction_order_method
           estimation
           2level
           4level
           8level
           search
               Bruteforce search

           log
       ch_mode
           Channel mode

           auto
               The mode is chosen automatically for each frame

           indep
               Channels are independently coded

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

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

   opus
       Opus encoder.

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

       Options

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

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

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

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

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

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

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

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

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

       Options

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

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

           In case VBR mode is enabled the option is ignored.

       ar  Set audio sampling rate (in Hz).

       channels
           Set the number of audio channels.

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

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

       profile
           Set audio profile.

           The following profiles are recognized:

           aac_low
               Low Complexity AAC (LC)

           aac_he
               High Efficiency AAC (HE-AAC)

           aac_he_v2
               High Efficiency AAC version 2 (HE-AACv2)

           aac_ld
               Low Delay AAC (LD)

           aac_eld
               Enhanced Low Delay AAC (ELD)

           If not specified it is set to aac_low.

       The following are private options of the libfdk_aac encoder.

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

           Default value is 1.

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

           Default value is 0.

       signaling
           Set SBR/PS signaling style.

           It can assume one of the following values:

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

           implicit
               implicit backwards compatible signaling

           explicit_sbr
               explicit SBR, implicit PS signaling

           explicit_hierarchical
               explicit hierarchical signaling

           Default value is default.

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

           Default value is 0.

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

           Must be a 16-bits non-negative integer.

           Default value is 0.

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

           Currently only the aac_low profile supports VBR encoding.

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

           1   32 kbps/channel

           2   40 kbps/channel

           3   48-56 kbps/channel

           4   64 kbps/channel

           5   about 80-96 kbps/channel

           Default value is 0.

       Examples

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

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

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

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

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

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

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

       Options

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

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

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

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

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

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

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

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

   libopencore-amrnb
       OpenCORE Adaptive Multi-Rate Narrowband encoder.

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

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

       Options

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

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

   libopus
       libopus Opus Interactive Audio Codec encoder wrapper.

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

       Option Mapping

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

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

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

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

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

           constrained (cvbr)
               Use constrained variable bit rate encoding.

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

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

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

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

           voip
               Favor improved speech intelligibility.

           audio
               Favor faithfulness to the input (the default).

           lowdelay
               Restrict to only the lowest delay modes.

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

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

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

   libshine
       Shine Fixed-Point MP3 encoder wrapper.

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

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

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

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

       See also libmp3lame.

       Options

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

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

   libtwolame
       TwoLAME MP2 encoder wrapper.

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

       Options

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

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

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

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

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

           stereo
               Stereo

           joint_stereo
               Joint stereo

           dual_channel
               Dual channel

           mono
               Mono

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

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

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

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

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

   libvo-amrwbenc
       VisualOn Adaptive Multi-Rate Wideband encoder.

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

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

       Options

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

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

   libvorbis
       libvorbis encoder wrapper.

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

       Options

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

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

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

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

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

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

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

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

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

   libwavpack
       A wrapper providing WavPack encoding through libwavpack.

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

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

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

       Options

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

       frame_size (--blocksize)
           Default is 32768.

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

           0 (-f)
               Fast mode.

           1   Normal (default) settings.

           2 (-h)
               High quality.

           3 (-hh)
               Very high quality.

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

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

   mjpeg
       Motion JPEG encoder.

       Options

       huffman
           Set the huffman encoding strategy. Possible values:

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

           optimal
               Compute and use optimal huffman tables.

   wavpack
       WavPack lossless audio encoder.

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

       See also libwavpack.

       Options

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

       Shared options

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

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

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

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

       Private options

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

           on (1)
               Force mid/side audio encoding.

           off (0)
               Force left/right audio encoding.

           auto
               Let the encoder decide automatically.

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

           on  enabled

           off disabled

VIDEO ENCODERS

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

   Hap
       Vidvox Hap video encoder.

       Options

       format integer
           Specifies the Hap format to encode.

           hap
           hap_alpha
           hap_q

           Default value is hap.

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

           Default value is 1.

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

           none
           snappy

           Default value is snappy.

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

       Options

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

   libkvazaar
       Kvazaar H.265/HEVC encoder.

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

       Options

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

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

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

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

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

       Options

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

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

       g   Set the GOP size.

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

       flags +global_header
           Set global header in the bitstream.

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

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

           fixed
               a fixed number of slices

           rowmb
               one slice per row of macroblocks

           auto
               automatic number of slices according to number of threads

           dyn dynamic slicing

           Default value is auto.

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

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

       max_nal_size
           Set maximum NAL size in bytes.

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

   libtheora
       libtheora Theora encoder wrapper.

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

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

       Options

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

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

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

       g   Set the GOP size.

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

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

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

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

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

       Examples

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

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

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

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

   libvpx
       VP8/VP9 format supported through libvpx.

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

       Options

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

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

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

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

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

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

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

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

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

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

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

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

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

           realtime
               Use realtime quality deadline.

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

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

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

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

       force_key_frames
           "VPX_EFLAG_FORCE_KF"

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

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

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

           arnr-strength
               Set altref noise reduction filter strength.

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

       error-resilient
           Enable error resiliency features.

       VP9-specific options
           lossless
               Enable lossless mode.

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

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

           frame-parallel
               Enable frame parallel decodability features.

           aq-mode
               Set adaptive quantization mode (0: off (default), 1: variance 2: complexity, 3: cyclic refresh,
               4: equator360).

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

               rgb sRGB
               bt709 bt709
               unspecified unknown
               bt470bg bt601
               smpte170m smpte170
               smpte240m smpte240
               bt2020_ncl bt2020
           row-mt boolean
               Enable row based multi-threading.

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

   libwebp
       libwebp WebP Image encoder wrapper

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

       Pixel Format

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

       Options

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

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

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

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

           none
               Do not use a preset.

           default
               Use the encoder default.

           picture
               Digital picture, like portrait, inner shot

           photo
               Outdoor photograph, with natural lighting

           drawing
               Hand or line drawing, with high-contrast details

           icon
               Small-sized colorful images

           text
               Text-like

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

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

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

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

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

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

       Supported Pixel Formats

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

       Options

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

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

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

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

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

       qmax (qpmax)
           Maximum quantizer scale.

       qdiff (qpstep)
           Maximum difference between quantizer scales.

       qblur (qblur)
           Quantizer curve blur

       qcomp (qcomp)
           Quantizer curve compression factor

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

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

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

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

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

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

           hex (hex)
               Hexagonal search with radius 2.

           umh (umh)
               Uneven multi-hexagon search.

           esa (esa)
               Exhaustive search.

           tesa (tesa)
               Hadamard exhaustive search (slowest).

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

       subq (subme)
           Sub-pixel motion estimation method.

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

       keyint_min (min-keyint)
           Minimum GOP size.

       coder
           Set entropy encoder. Possible values:

           ac  Enable CABAC.

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

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

           chroma
               Enable chroma in motion estimation.

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

       threads (threads)
           Number of encoding threads.

       thread_type
           Set multithreading technique. Possible values:

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

           frame
               Frame-based multithreading.

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

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

       tune (tune)
           Set tuning of the encoding params.

       profile (profile)
           Set profile restrictions.

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

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

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

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

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

           none (0)
               Disabled.

           variance (1)
               Variance AQ (complexity mask).

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

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

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

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

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

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

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

           none (0)
               Disabled

           simple (1)
               Enable only weighted refs

           smart (2)
               Enable both weighted refs and duplicates

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

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

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

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

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

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

           none (none)
               Disabled.

           strict (strict)
               Strictly hierarchical pyramid.

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

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

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

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

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

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

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

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

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

           p8x8
               8x8 P-frame partition.

           p4x4
               4x4 P-frame partition.

           b8x8
               4x4 B-frame partition.

           i8x8
               8x8 I-frame partition.

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

           none (none)
               Do not consider any partitions.

           all (all)
               Consider every partition.

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

           none (none)
               Disable MV prediction.

           spatial (spatial)
               Enable spatial predicting.

           temporal (temporal)
               Enable temporal predicting.

           auto (auto)
               Automatically decided.

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

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

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

           none (none)
               Disable HRD information signaling.

           vbr (vbr)
               Variable bit rate.

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

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

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

           For example to specify libx264 encoding options with ffmpeg:

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

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

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

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

           For example to specify libx264 encoding options with ffmpeg:

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

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

   libx265
       x265 H.265/HEVC encoder wrapper.

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

       Options

       preset
           Set the x265 preset.

       tune
           Set the x265 tune parameter.

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

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

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

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

   libxvid
       Xvid MPEG-4 Part 2 encoder wrapper.

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

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

       Options

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

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

           mv4 Use four motion vector by macroblock.

           aic Enable high quality AC prediction.

           gray
               Only encode grayscale.

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

           qpel
               Enable quarter-pixel motion compensation.

           cgop
               Enable closed GOP.

           global_header
               Place global headers in extradata instead of every keyframe.

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

           zero
               Use no motion estimation (default).

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

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

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

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

           simple
               Use macroblock comparing function algorithm (default).

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

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

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

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

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

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

           off Disable displaying of SSIM information.

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

                       Average SSIM: %f

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

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

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

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

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

   mpeg2
       MPEG-2 video encoder.

       Options

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

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

           0
           never
               Never write it.

           1
           always
               Always write it.

   png
       PNG image encoder.

       Private options

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

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

   ProRes
       Apple ProRes encoder.

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

       Private Options for prores-ks

       profile integer
           Select the ProRes profile to encode

           proxy
           lt
           standard
           hq
           4444
           4444xq
       quant_mat integer
           Select quantization matrix.

           auto
           default
           proxy
           lt
           standard
           hq

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

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

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

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

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

       Speed considerations

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

       Setting a higher bits_per_mb limit will improve the speed.

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

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

       The ratecontrol method is selected as follows:

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

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

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

           -   ICQ -- intelligent constant quality otherwise.

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

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

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

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

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

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

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

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

       •   g/gop_size -> GopPicSizebf/max_b_frames+1 -> GopRefDistrc_init_occupancy/rc_initial_buffer_occupancy -> InitialDelayInKBslices -> NumSlicerefs -> NumRefFrameb_strategy/b_frame_strategy -> BRefTypecgop/CLOSED_GOP codec flag -> GopOptFlag

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

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

   snow
       Options

       iterative_dia_size
           dia size for the iterative motion estimation

   VAAPI encoders
       Wrappers for hardware encoders accessible via VAAPI.

       These encoders only accept input in VAAPI hardware surfaces.  If you have input in software frames, use
       the hwupload filter to upload them to the GPU.

       The following standard libavcodec options are used:

       •   g / gop_sizebf / max_b_framesprofilelevelb / bit_ratemaxrate / rc_max_ratebufsize / rc_buffer_sizerc_init_occupancy / rc_initial_buffer_occupancycompression_level

           Speed / quality tradeoff: higher values are faster / worse quality.

       •   q / global_quality

           Size / quality tradeoff: higher values are smaller / worse quality.

       •   qmin (only: qmax is not supported)

       •   i_qfactor / i_quant_factori_qoffset / i_quant_offsetb_qfactor / b_quant_factorb_qoffset / b_quant_offset

       h264_vaapi
           profile sets the value of profile_idc and the constraint_set*_flags.  level sets the value of
           level_idc.

           low_power
               Use low-power encoding mode.

           coder
               Set entropy encoder (default is cabac).  Possible values:

               ac
               cabac
                   Use CABAC.

               vlc
               cavlc
                   Use CAVLC.

       hevc_vaapi
           profile and level set the values of general_profile_idc and general_level_idc respectively.

       mjpeg_vaapi
           Always encodes using the standard quantisation and huffman tables - global_quality scales the
           standard quantisation table (range 1-100).

       mpeg2_vaapi
           profile and level set the value of profile_and_level_indication.

           No rate control is supported.

       vp8_vaapi
           B-frames are not supported.

           global_quality sets the q_idx used for non-key frames (range 0-127).

           loop_filter_level
           loop_filter_sharpness
               Manually set the loop filter parameters.

       vp9_vaapi
           global_quality sets the q_idx used for P-frames (range 0-255).

           loop_filter_level
           loop_filter_sharpness
               Manually set the loop filter parameters.

           B-frames are supported, but the output stream is always in encode order rather than display order.
           If B-frames are enabled, it may be necessary to use the vp9_raw_reorder bitstream filter to modify
           the output stream to display frames in the correct order.

           Only normal frames are produced - the vp9_superframe bitstream filter may be required to produce a
           stream usable with all decoders.

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

       Options

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

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

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

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

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

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

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

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

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

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

SUBTITLES ENCODERS

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

       Options

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

           By default, this work-around is disabled.

SEE ALSO

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

AUTHORS

       The FFmpeg developers.

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

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

                                                                                                FFMPEG-CODECS(1)