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ffmpeg-codecs(1)

NAME

   ffmpeg-codecs - FFmpeg codecs

DESCRIPTION

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

CODEC OPTIONS

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

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

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

   The list of supported options follow:

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

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

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

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

       Possible values:

       mv4 Use four motion vector by macroblock (mpeg4).

       qpel
           Use 1/4 pel motion compensation.

       loop
           Use loop filter.

       qscale
           Use fixed qscale.

       gmc Use gmc.

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

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

       pass2
           Use internal 2pass ratecontrol in second pass mode.

       gray
           Only decode/encode grayscale.

       emu_edge
           Do not draw edges.

       psnr
           Set error[?] variables during encoding.

       truncated
       naq Normalize adaptive quantization.

       ildct
           Use interlaced DCT.

       low_delay
           Force low delay.

       global_header
           Place global headers in extradata instead of every keyframe.

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

       aic Apply H263 advanced intra coding / mpeg4 ac prediction.

       cbp Deprecated, use mpegvideo private options instead.

       qprd
           Deprecated, use mpegvideo private options instead.

       ilme
           Apply interlaced motion estimation.

       cgop
           Use closed gop.

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

       Possible values:

       zero
           zero motion estimation (fastest)

       full
           full motion estimation (slowest)

       epzs
           EPZS motion estimation (default)

       esa esa motion estimation (alias for full)

       tesa
           tesa motion estimation

       dia dia motion estimation (alias for epzs)

       log log motion estimation

       phods
           phods motion estimation

       x1  X1 motion estimation

       hex hex motion estimation

       umh umh motion estimation

       iter
           iter motion estimation

   extradata_size integer
       Set extradata size.

   time_base rational number
       Set codec time base.

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

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

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

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

   cutoff integer (encoding,audio)
       Set cutoff bandwidth.

   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_1
           SMPTE ST 428-1

       smpte431
           SMPTE 431-2

       smpte432
           SMPTE 432-1

   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 Log

       log_sqrt
           Log square root

       iec61966_2_4
           IEC 61966-2-4

       bt1361
           BT.1361

       iec61966_2_1
           IEC 61966-2-1

       bt2020_10bit
           BT.2020 - 10 bit

       bt2020_12bit
           BT.2020 - 12 bit

       smpte2084
           SMPTE ST 2084

       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

       bt2020_ncl
           BT.2020 NCL

       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.

   chroma_sample_location integer (decoding/encoding,video)
   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

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.

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.

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.

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.

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).

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".

VIDEO ENCODERS

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

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.

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.

snow
Options

iterative_dia_size
dia size for the iterative motion estimation

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 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).

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.

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.

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.

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.

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.

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)

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ffmpeg-codecs(1)

NAME

DESCRIPTION

CODEC OPTIONS

DECODERS

VIDEO DECODERS

AUDIO DECODERS

SUBTITLES DECODERS

ENCODERS

AUDIO ENCODERS

VIDEO ENCODERS

SUBTITLES ENCODERS

SEE ALSO

AUTHORS

Opportunity

Free Software

Free Books

Education