Provided by: ffmpeg_3.3.4-2_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 integer (decoding,video)
           Set to 1 to disable processing alpha (transparency). This works like the gray flag in
           the flags option which skips chroma information instead of alpha. Default is 0.

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

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

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

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

DECODERS

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

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

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

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

VIDEO DECODERS

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

   hevc
       HEVC / H.265 decoder.

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

   rawvideo
       Raw video decoder.

       This decoder decodes rawvideo streams.

       Options

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

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

           0   bottom-field-first is assumed

           1   top-field-first is assumed

AUDIO DECODERS

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

   ac3
       AC-3 audio decoder.

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

       AC-3 Decoder Options

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

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

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

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

   flac
       FLAC audio decoder.

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

       FLAC Decoder options

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

   ffwavesynth
       Internal wave synthetizer.

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

   libcelt
       libcelt decoder wrapper.

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

   libgsm
       libgsm decoder wrapper.

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

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

   libilbc
       libilbc decoder wrapper.

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

       Options

       The following option is supported by the libilbc wrapper.

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

   libopencore-amrnb
       libopencore-amrnb decoder wrapper.

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

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

   libopencore-amrwb
       libopencore-amrwb decoder wrapper.

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

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

   libopus
       libopus decoder wrapper.

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

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

SUBTITLES DECODERS

   dvbsub
       Options

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

           0   Never compute CLUT

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

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

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

       Options

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

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

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

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

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

       Options

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

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

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

       txt_left
           X offset of generated bitmaps, default is 0.

       txt_top
           Y offset of generated bitmaps, default is 0.

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

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

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

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

ENCODERS

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

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

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

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

AUDIO ENCODERS

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

   aac
       Advanced Audio Coding (AAC) encoder.

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

       Options

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

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

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

       aac_coder
           Set AAC encoder coding method. Possible values:

           twoloop
               Two loop searching (TLS) method.

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

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

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

           fast
               Constant quantizer method.

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

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

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

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

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

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

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

       profile
           Sets the encoding profile, possible values:

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

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

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

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

           If this option is unspecified it is set to aac_low.

   ac3 and ac3_fixed
       AC-3 audio encoders.

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

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

       AC-3 Metadata

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

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

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

       Metadata Control Options

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

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

           1   Metadata values can be changed before encoding each frame.

       Downmix Levels

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

           0.707
               Apply -3dB gain

           0.595
               Apply -4.5dB gain (default)

           0.500
               Apply -6dB gain

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

           0.707
               Apply -3dB gain

           0.500
               Apply -6dB gain (default)

           0.000
               Silence Surround Channel(s)

       Audio Production Information

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

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

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

           0
           notindicated
               Not Indicated (default)

           1
           large
               Large Room

           2
           small
               Small Room

       Other Metadata Options

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

           0
           off No Copyright Exists (default)

           1
           on  Copyright Exists

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

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

           0
           notindicated
               Not Indicated (default)

           1
           off Not Dolby Surround Encoded

           2
           on  Dolby Surround Encoded

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

           0
           off Not Original Source

           1
           on  Original Source (default)

       Extended Bitstream Information

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

       Extended Bitstream Information - Part 1

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

           0
           notindicated
               Not Indicated (default)

           1
           ltrt
               Lt/Rt Downmix Preferred

           2
           loro
               Lo/Ro Downmix Preferred

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

           1.414
               Apply +3dB gain

           1.189
               Apply +1.5dB gain

           1.000
               Apply 0dB gain

           0.841
               Apply -1.5dB gain

           0.707
               Apply -3.0dB gain

           0.595
               Apply -4.5dB gain (default)

           0.500
               Apply -6.0dB gain

           0.000
               Silence Center Channel

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

           0.841
               Apply -1.5dB gain

           0.707
               Apply -3.0dB gain

           0.595
               Apply -4.5dB gain

           0.500
               Apply -6.0dB gain (default)

           0.000
               Silence Surround Channel(s)

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

           1.414
               Apply +3dB gain

           1.189
               Apply +1.5dB gain

           1.000
               Apply 0dB gain

           0.841
               Apply -1.5dB gain

           0.707
               Apply -3.0dB gain

           0.595
               Apply -4.5dB gain (default)

           0.500
               Apply -6.0dB gain

           0.000
               Silence Center Channel

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

           0.841
               Apply -1.5dB gain

           0.707
               Apply -3.0dB gain

           0.595
               Apply -4.5dB gain

           0.500
               Apply -6.0dB gain (default)

           0.000
               Silence Surround Channel(s)

       Extended Bitstream Information - Part 2

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

           0
           notindicated
               Not Indicated (default)

           1
           on  Dolby Surround EX Off

           2
           off Dolby Surround EX On

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

           0
           notindicated
               Not Indicated (default)

           1
           on  Dolby Headphone Off

           2
           off Dolby Headphone On

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

           0
           standard
               Standard A/D Converter (default)

           1
           hdcd
               HDCD A/D Converter

       Other AC-3 Encoding Options

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

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

       Floating-Point-Only AC-3 Encoding Options

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

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

           -1
           auto
               Selected by Encoder (default)

           0
           off Disable Channel Coupling

           1
           on  Enable Channel Coupling

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

           -1
           auto
               Selected by Encoder (default)

   flac
       FLAC (Free Lossless Audio Codec) Encoder

       Options

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

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

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

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

       lpc_type
           Sets the first stage LPC algorithm

           none
               LPC is not used

           fixed
               fixed LPC coefficients

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

       min_partition_order
           The minimum partition order

       max_partition_order
           The maximum partition order

       prediction_order_method
           estimation
           2level
           4level
           8level
           search
               Bruteforce search

           log
       ch_mode
           Channel mode

           auto
               The mode is chosen automatically for each frame

           indep
               Chanels are independently coded

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

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

   opus
       Opus encoder.

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

       Options

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

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

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

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

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

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

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

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

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

       Options

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

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

           In case VBR mode is enabled the option is ignored.

       ar  Set audio sampling rate (in Hz).

       channels
           Set the number of audio channels.

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

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

       profile
           Set audio profile.

           The following profiles are recognized:

           aac_low
               Low Complexity AAC (LC)

           aac_he
               High Efficiency AAC (HE-AAC)

           aac_he_v2
               High Efficiency AAC version 2 (HE-AACv2)

           aac_ld
               Low Delay AAC (LD)

           aac_eld
               Enhanced Low Delay AAC (ELD)

           If not specified it is set to aac_low.

       The following are private options of the libfdk_aac encoder.

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

           Default value is 1.

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

           Default value is 0.

       signaling
           Set SBR/PS signaling style.

           It can assume one of the following values:

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

           implicit
               implicit backwards compatible signaling

           explicit_sbr
               explicit SBR, implicit PS signaling

           explicit_hierarchical
               explicit hierarchical signaling

           Default value is default.

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

           Default value is 0.

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

           Must be a 16-bits non-negative integer.

           Default value is 0.

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

           Currently only the aac_low profile supports VBR encoding.

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

           1   32 kbps/channel

           2   40 kbps/channel

           3   48-56 kbps/channel

           4   64 kbps/channel

           5   about 80-96 kbps/channel

           Default value is 0.

       Examples

       ·   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).

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

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

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

   libwebp
       libwebp WebP Image encoder wrapper

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

       Pixel Format

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

       Options

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

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

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

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

           none
               Do not use a preset.

           default
               Use the encoder default.

           picture
               Digital picture, like portrait, inner shot

           photo
               Outdoor photograph, with natural lighting

           drawing
               Hand or line drawing, with high-contrast details

           icon
               Small-sized colorful images

           text
               Text-like

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

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

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

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

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

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

       Supported Pixel Formats

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

       Options

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

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

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

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

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

       qmax (qpmax)
           Maximum quantizer scale.

       qdiff (qpstep)
           Maximum difference between quantizer scales.

       qblur (qblur)
           Quantizer curve blur

       qcomp (qcomp)
           Quantizer curve compression factor

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

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

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

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

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

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

           hex (hex)
               Hexagonal search with radius 2.

           umh (umh)
               Uneven multi-hexagon search.

           esa (esa)
               Exhaustive search.

           tesa (tesa)
               Hadamard exhaustive search (slowest).

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

       subq (subme)
           Sub-pixel motion estimation method.

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

       keyint_min (min-keyint)
           Minimum GOP size.

       coder
           Set entropy encoder. Possible values:

           ac  Enable CABAC.

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

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

           chroma
               Enable chroma in motion estimation.

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

       threads (threads)
           Number of encoding threads.

       thread_type
           Set multithreading technique. Possible values:

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

           frame
               Frame-based multithreading.

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

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

       tune (tune)
           Set tuning of the encoding params.

       profile (profile)
           Set profile restrictions.

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

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

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

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

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

           none (0)
               Disabled.

           variance (1)
               Variance AQ (complexity mask).

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

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

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

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

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

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

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

           none (0)
               Disabled

           simple (1)
               Enable only weighted refs

           smart (2)
               Enable both weighted refs and duplicates

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

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

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

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

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

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

           none (none)
               Disabled.

           strict (strict)
               Strictly hierarchical pyramid.

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

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

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

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

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

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

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

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

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

           p8x8
               8x8 P-frame partition.

           p4x4
               4x4 P-frame partition.

           b8x8
               4x4 B-frame partition.

           i8x8
               8x8 I-frame partition.

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

           none (none)
               Do not consider any partitions.

           all (all)
               Consider every partition.

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

           none (none)
               Disable MV prediction.

           spatial (spatial)
               Enable spatial predicting.

           temporal (temporal)
               Enable temporal predicting.

           auto (auto)
               Automatically decided.

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

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

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

           none (none)
               Disable HRD information signaling.

           vbr (vbr)
               Variable bit rate.

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

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

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

           For example to specify libx264 encoding options with ffmpeg:

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

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

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

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

           For example to specify libx264 encoding options with ffmpeg:

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

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

   libx265
       x265 H.265/HEVC encoder wrapper.

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

       Options

       preset
           Set the x265 preset.

       tune
           Set the x265 tune parameter.

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

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

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

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

   libxvid
       Xvid MPEG-4 Part 2 encoder wrapper.

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

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

       Options

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

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

           mv4 Use four motion vector by macroblock.

           aic Enable high quality AC prediction.

           gray
               Only encode grayscale.

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

           qpel
               Enable quarter-pixel motion compensation.

           cgop
               Enable closed GOP.

           global_header
               Place global headers in extradata instead of every keyframe.

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

           zero
               Use no motion estimation (default).

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

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

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

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

           simple
               Use macroblock comparing function algorithm (default).

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

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

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

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

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

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

           off Disable displaying of SSIM information.

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

                       Average SSIM: %f

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

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

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

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

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

   mpeg2
       MPEG-2 video encoder.

       Options

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

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

           0
           never
               Never write it.

           1
           always
               Always write it.

   png
       PNG image encoder.

       Private options

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

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

   ProRes
       Apple ProRes encoder.

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

       Private Options for prores-ks

       profile integer
           Select the ProRes profile to encode

           proxy
           lt
           standard
           hq
           4444
       quant_mat integer
           Select quantization matrix.

           auto
           default
           proxy
           lt
           standard
           hq

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

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

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

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

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

       Speed considerations

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

       Setting a higher bits_per_mb limit will improve the speed.

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

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

       The ratecontrol method is selected as follows:

       ·   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 -> GopPicSize

       ·   bf/max_b_frames+1 -> GopRefDist

       ·   rc_init_occupancy/rc_initial_buffer_occupancy -> InitialDelayInKB

       ·   slices -> NumSlice

       ·   refs -> NumRefFrame

       ·   b_strategy/b_frame_strategy -> BRefType

       ·   cgop/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

   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)