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

NAME
       ffmpeg-codecs - FFmpeg codecs

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

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

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

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

       The list of supported options follow:

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

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

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

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

	   Possible values:

	   mv4 Use four motion vector by macroblock (mpeg4).

	   qpel
	       Use 1/4 pel motion compensation.

	   loop
	       Use loop filter.

	   qscale
	       Use fixed qscale.

	   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
	   ildct
	       Use interlaced DCT.

	   low_delay
	       Force low delay.

	   global_header
	       Place global headers in extradata instead of every keyframe.

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

	   aic Apply H263 advanced intra coding / mpeg4 ac prediction.

	   cbp Deprecated, use mpegvideo private options instead.

	   qprd
	       Deprecated, use mpegvideo private options instead.

	   ilme
	       Apply interlaced motion estimation.

	   cgop
	       Use closed gop.

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

	   Possible values:

	   zero
	       zero motion estimation (fastest)

	   full
	       full motion estimation (slowest)

	   epzs
	       EPZS motion estimation (default)

	   esa esa motion estimation (alias for full)

	   tesa
	       tesa motion estimation

	   dia dia motion estimation (alias for epzs)

	   log log motion estimation

	   phods
	       phods motion estimation

	   x1  X1 motion estimation

	   hex hex motion estimation

	   umh umh motion estimation

	   iter
	       iter motion estimation

       extradata_size integer
	   Set extradata size.

       time_base rational number
	   Set codec time base.

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

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

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

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

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

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

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

       frame_number integer
	   Set the frame number.

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

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

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

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

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

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

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

	   Default value is 0.

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

       rc_strategy integer (encoding,video)
	   Set ratecontrol method.

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

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

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

	   Possible values:

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

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

	   ump4
	       (autodetected if fourcc==UMP4)

	   no_padding
	       padding bug (autodetected)

	   amv
	   ac_vlc
	       illegal vlc bug (autodetected per fourcc)

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

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

	   edge
	       edge padding bug (autodetected per fourcc/version)

	   hpel_chroma
	   dc_clip
	   ms  Workaround various bugs in microsoft broken decoders.

	   trunc
	       trancated frames

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

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

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

	   Possible values:

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

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

	   normal
	   unofficial
	       allow unofficial extensions

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

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

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

	   Possible values:

	   crccheck
	       verify embedded CRCs

	   bitstream
	       detect bitstream specification deviations

	   buffer
	       detect improper bitstream length

	   explode
	       abort decoding on minor error detection

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

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

	   compliant
	       consider all spec non compliancies as errors

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

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

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

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

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

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

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

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

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

       rc_buf_aggressivity float (encoding,video)
	   Currently useless.

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

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

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

       dct integer (encoding,video)
	   Set DCT algorithm.

	   Possible values:

	   auto
	       autoselect a good one (default)

	   fastint
	       fast integer

	   int accurate integer

	   mmx
	   altivec
	   faan
	       floating point AAN DCT

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

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

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

       p_mask float (encoding,video)
	   Set inter masking.

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

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

	   Possible values:

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

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

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

	   Possible values:

	   guess_mvs
	       iterative motion vector (MV) search (slow)

	   deblock
	       use strong deblock filter for damaged MBs

	   favor_inter
	       favor predicting from the previous frame instead of the current

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

	   Possible values:

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

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

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

	   Possible values:

	   pict
	       picture info

	   rc  rate control

	   bitstream
	   mb_type
	       macroblock (MB) type

	   qp  per-block quantization parameter (QP)

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

	   skip
	   startcode
	   er  error recognition

	   mmco
	       memory management control operations (H.264)

	   bugs
	   buffers
	       picture buffer allocations

	   thread_ops
	       threading operations

	   nomc
	       skip motion compensation

       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
       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.

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

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

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

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

       request_channel_layout integer (decoding,audio)
	   Possible values:

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

	   bt709
	       BT.709

	   bt470m
	       BT.470 M

	   bt470bg
	       BT.470 BG

	   smpte170m
	       SMPTE 170 M

	   smpte240m
	       SMPTE 240 M

	   film
	       Film

	   bt2020
	       BT.2020

	   smpte428
	   smpte428_1
	       SMPTE ST 428-1

	   smpte431
	       SMPTE 431-2

	   smpte432
	       SMPTE 432-1

	   jedec-p22
	       JEDEC P22

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

	   bt709
	       BT.709

	   gamma22
	       BT.470 M

	   gamma28
	       BT.470 BG

	   smpte170m
	       SMPTE 170 M

	   smpte240m
	       SMPTE 240 M

	   linear
	       Linear

	   log
	   log100
	       Log

	   log_sqrt
	   log316
	       Log square root

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

	   bt1361
	   bt1361e
	       BT.1361

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

	   bt2020_10
	   bt2020_10bit
	       BT.2020 - 10 bit

	   bt2020_12
	   bt2020_12bit
	       BT.2020 - 12 bit

	   smpte2084
	       SMPTE ST 2084

	   smpte428
	   smpte428_1
	       SMPTE ST 428-1

	   arib-std-b67
	       ARIB STD-B67

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

	   rgb RGB

	   bt709
	       BT.709

	   fcc FCC

	   bt470bg
	       BT.470 BG

	   smpte170m
	       SMPTE 170 M

	   smpte240m
	       SMPTE 240 M

	   ycocg
	       YCOCG

	   bt2020nc
	   bt2020_ncl
	       BT.2020 NCL

	   bt2020c
	   bt2020_cl
	       BT.2020 CL

	   smpte2085
	       SMPTE 2085

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

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

	   pc
	   jpeg
	       JPEG (2^n-1)

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

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

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

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

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

	   Possible values:

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

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

	   frame
	       Decode more than one frame at once.

	   Default value is slice+frame.

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

	   Possible values:

	   ma  Main Audio Service

	   ef  Effects

	   vi  Visually Impaired

	   hi  Hearing Impaired

	   di  Dialogue

	   co  Commentary

	   em  Emergency

	   vo  Voice Over

	   ka  Karaoke

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

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

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

	   progressive
	       Progressive video

	   tt  Interlaced video, top field coded and displayed first

	   bb  Interlaced video, bottom field coded and displayed first

	   tb  Interlaced video, top coded first, bottom displayed first

	   bt  Interlaced video, bottom coded first, top displayed first

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

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

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

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

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

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

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

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

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

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

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

   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

   libdavs2
       AVS2-P2/IEEE1857.4 video decoder wrapper.

       This decoder allows libavcodec to decode AVS2 streams with davs2
       library.

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

   ac3
       AC-3 audio decoder.

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

       AC-3 Decoder Options

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

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

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

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

   flac
       FLAC audio decoder.

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

       FLAC Decoder options

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

   ffwavesynth
       Internal wave synthesizer.

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

   libcelt
       libcelt decoder wrapper.

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

   libgsm
       libgsm decoder wrapper.

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

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

   libilbc
       libilbc decoder wrapper.

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

       Options

       The following option is supported by the libilbc wrapper.

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

   libopencore-amrnb
       libopencore-amrnb decoder wrapper.

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

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

   libopencore-amrwb
       libopencore-amrwb decoder wrapper.

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

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

   libopus
       libopus decoder wrapper.

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

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

SUBTITLES DECODERS
   dvbsub
       Options

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

	   0   Never compute CLUT

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

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

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

       Options

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

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

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

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

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

       Options

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

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

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

       txt_left
	   X offset of generated bitmaps, default is 0.

       txt_top
	   Y offset of generated bitmaps, default is 0.

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

       txt_duration
	   Sets the display duration of the decoded teletext pages or
	   subtitles in milliseconds. Default value is -1 which means infinity
	   or until the next subtitle event comes.

       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.

	   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.

	       Uses a cheaper version of twoloop algorithm that doesn't try to
	       do as many clever adjustments. Worse with low bitrates (less
	       than 64kbps), but is better and much faster at higher bitrates.
	       This is the default choice for a coder

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

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

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

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

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

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

       profile
	   Sets the encoding profile, possible values:

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

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

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

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

	   If this option is unspecified it is set to aac_low.

   ac3 and ac3_fixed
       AC-3 audio encoders.

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

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

       AC-3 Metadata

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

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

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

       Metadata Control Options

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

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

	   1   Metadata values can be changed before encoding each frame.

       Downmix Levels

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

	   0.707
	       Apply -3dB gain

	   0.595
	       Apply -4.5dB gain (default)

	   0.500
	       Apply -6dB gain

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

	   0.707
	       Apply -3dB gain

	   0.500
	       Apply -6dB gain (default)

	   0.000
	       Silence Surround Channel(s)

       Audio Production Information

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

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

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

	   0
	   notindicated
	       Not Indicated (default)

	   1
	   large
	       Large Room

	   2
	   small
	       Small Room

       Other Metadata Options

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

	   0
	   off No Copyright Exists (default)

	   1
	   on  Copyright Exists

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

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

	   0
	   notindicated
	       Not Indicated (default)

	   1
	   off Not Dolby Surround Encoded

	   2
	   on  Dolby Surround Encoded

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

	   0
	   off Not Original Source

	   1
	   on  Original Source (default)

       Extended Bitstream Information

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

       Extended Bitstream Information - Part 1

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

	   0
	   notindicated
	       Not Indicated (default)

	   1
	   ltrt
	       Lt/Rt Downmix Preferred

	   2
	   loro
	       Lo/Ro Downmix Preferred

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

	   1.414
	       Apply +3dB gain

	   1.189
	       Apply +1.5dB gain

	   1.000
	       Apply 0dB gain

	   0.841
	       Apply -1.5dB gain

	   0.707
	       Apply -3.0dB gain

	   0.595
	       Apply -4.5dB gain (default)

	   0.500
	       Apply -6.0dB gain

	   0.000
	       Silence Center Channel

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

	   0.841
	       Apply -1.5dB gain

	   0.707
	       Apply -3.0dB gain

	   0.595
	       Apply -4.5dB gain

	   0.500
	       Apply -6.0dB gain (default)

	   0.000
	       Silence Surround Channel(s)

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

	   1.414
	       Apply +3dB gain

	   1.189
	       Apply +1.5dB gain

	   1.000
	       Apply 0dB gain

	   0.841
	       Apply -1.5dB gain

	   0.707
	       Apply -3.0dB gain

	   0.595
	       Apply -4.5dB gain (default)

	   0.500
	       Apply -6.0dB gain

	   0.000
	       Silence Center Channel

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

	   0.841
	       Apply -1.5dB gain

	   0.707
	       Apply -3.0dB gain

	   0.595
	       Apply -4.5dB gain

	   0.500
	       Apply -6.0dB gain (default)

	   0.000
	       Silence Surround Channel(s)

       Extended Bitstream Information - Part 2

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

	   0
	   notindicated
	       Not Indicated (default)

	   1
	   on  Dolby Surround EX Off

	   2
	   off Dolby Surround EX On

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

	   0
	   notindicated
	       Not Indicated (default)

	   1
	   on  Dolby Headphone Off

	   2
	   off Dolby Headphone On

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

	   0
	   standard
	       Standard A/D Converter (default)

	   1
	   hdcd
	       HDCD A/D Converter

       Other AC-3 Encoding Options

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

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

       Floating-Point-Only AC-3 Encoding Options

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

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

	   -1
	   auto
	       Selected by Encoder (default)

	   0
	   off Disable Channel Coupling

	   1
	   on  Enable Channel Coupling

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

	   -1
	   auto
	       Selected by Encoder (default)

   flac
       FLAC (Free Lossless Audio Codec) Encoder

       Options

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

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

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

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

       lpc_type
	   Sets the first stage LPC algorithm

	   none
	       LPC is not used

	   fixed
	       fixed LPC coefficients

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

       min_partition_order
	   The minimum partition order

       max_partition_order
	   The maximum partition order

       prediction_order_method
	   estimation
	   2level
	   4level
	   8level
	   search
	       Bruteforce search

	   log
       ch_mode
	   Channel mode

	   auto
	       The mode is chosen automatically for each frame

	   indep
	       Channels are independently coded

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

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

   opus
       Opus encoder.

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

       Options

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

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

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

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

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

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

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

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

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

       Options

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

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

	   In case VBR mode is enabled the option is ignored.

       ar  Set audio sampling rate (in Hz).

       channels
	   Set the number of audio channels.

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

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

       profile
	   Set audio profile.

	   The following profiles are recognized:

	   aac_low
	       Low Complexity AAC (LC)

	   aac_he
	       High Efficiency AAC (HE-AAC)

	   aac_he_v2
	       High Efficiency AAC version 2 (HE-AACv2)

	   aac_ld
	       Low Delay AAC (LD)

	   aac_eld
	       Enhanced Low Delay AAC (ELD)

	   If not specified it is set to aac_low.

       The following are private options of the libfdk_aac encoder.

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

	   Default value is 1.

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

	   Default value is 0.

       signaling
	   Set SBR/PS signaling style.

	   It can assume one of the following values:

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

	   implicit
	       implicit backwards compatible signaling

	   explicit_sbr
	       explicit SBR, implicit PS signaling

	   explicit_hierarchical
	       explicit hierarchical signaling

	   Default value is default.

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

	   Default value is 0.

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

	   Must be a 16-bits non-negative integer.

	   Default value is 0.

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

	   Currently only the aac_low profile supports VBR encoding.

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

	   1   32 kbps/channel

	   2   40 kbps/channel

	   3   48-56 kbps/channel

	   4   64 kbps/channel

	   5   about 80-96 kbps/channel

	   Default value is 0.

       Examples

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

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

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

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

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

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

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

       Options

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

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

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

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

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

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

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

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

   libopencore-amrnb
       OpenCORE Adaptive Multi-Rate Narrowband encoder.

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

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

       Options

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

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

   libopus
       libopus Opus Interactive Audio Codec encoder wrapper.

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

       Option Mapping

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

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

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

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

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

	   constrained (cvbr)
	       Use constrained variable bit rate encoding.

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

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

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

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

	   voip
	       Favor improved speech intelligibility.

	   audio
	       Favor faithfulness to the input (the default).

	   lowdelay
	       Restrict to only the lowest delay modes.

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

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

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

       apply_phase_inv (N.A.) (requires libopus >= 1.2)
	   If set to 0, disables the use of phase inversion for intensity
	   stereo, improving the quality of mono downmixes, but slightly
	   reducing normal stereo quality. The default is 1 (phase inversion
	   enabled).

   libshine
       Shine Fixed-Point MP3 encoder wrapper.

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

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

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

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

       See also libmp3lame.

       Options

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

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

   libtwolame
       TwoLAME MP2 encoder wrapper.

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

       Options

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

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

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

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

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

	   stereo
	       Stereo

	   joint_stereo
	       Joint stereo

	   dual_channel
	       Dual channel

	   mono
	       Mono

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

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

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

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

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

   libvo-amrwbenc
       VisualOn Adaptive Multi-Rate Wideband encoder.

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

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

       Options

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

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

   libvorbis
       libvorbis encoder wrapper.

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

       Options

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

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

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

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

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

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

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

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

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

   libwavpack
       A wrapper providing WavPack encoding through libwavpack.

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

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

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

       Options

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

       frame_size (--blocksize)
	   Default is 32768.

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

	   0 (-f)
	       Fast mode.

	   1   Normal (default) settings.

	   2 (-h)
	       High quality.

	   3 (-hh)
	       Very high quality.

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

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

   mjpeg
       Motion JPEG encoder.

       Options

       huffman
	   Set the huffman encoding strategy. Possible values:

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

	   optimal
	       Compute and use optimal huffman tables.

   wavpack
       WavPack lossless audio encoder.

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

       See also libwavpack.

       Options

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

       Shared options

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

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

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

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

       Private options

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

	   on (1)
	       Force mid/side audio encoding.

	   off (0)
	       Force left/right audio encoding.

	   auto
	       Let the encoder decide automatically.

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

	   on  enabled

	   off disabled

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

   Hap
       Vidvox Hap video encoder.

       Options

       format integer
	   Specifies the Hap format to encode.

	   hap
	   hap_alpha
	   hap_q

	   Default value is hap.

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

	   Default value is 1.

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

	   none
	   snappy

	   Default value is snappy.

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

       Options

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

   libkvazaar
       Kvazaar H.265/HEVC encoder.

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

       Options

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

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

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

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

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

       Options

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

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

       g   Set the GOP size.

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

       flags +global_header
	   Set global header in the bitstream.

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

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

	   fixed
	       a fixed number of slices

	   rowmb
	       one slice per row of macroblocks

	   auto
	       automatic number of slices according to number of threads

	   dyn dynamic slicing

	   Default value is auto.

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

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

       max_nal_size
	   Set maximum NAL size in bytes.

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

   libtheora
       libtheora Theora encoder wrapper.

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

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

       Options

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

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

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

       g   Set the GOP size.

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

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

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

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

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

       Examples

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

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

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

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

   libvpx
       VP8/VP9 format supported through libvpx.

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

       Options

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

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

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

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

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

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

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

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

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

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

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

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

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

	   realtime
	       Use realtime quality deadline.

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

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

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

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

       force_key_frames
	   "VPX_EFLAG_FORCE_KF"

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

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

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

	   arnr-strength
	       Set altref noise reduction filter strength.

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

       error-resilient
	   Enable error resiliency features.

       VP9-specific options
	   lossless
	       Enable lossless mode.

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

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

	   frame-parallel
	       Enable frame parallel decodability features.

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

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

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

	   tune-content
	       Set content type: default (0), screen (1), film (2).

	   corpus-complexity
	       Corpus VBR mode is a variant of standard VBR where the
	       complexity distribution midpoint is passed in rather than
	       calculated for a specific clip or chunk.

	       The valid range is [0, 10000]. 0 (default) uses standard VBR.

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

   libwebp
       libwebp WebP Image encoder wrapper

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

       Pixel Format

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

       Options

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

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

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

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

	   none
	       Do not use a preset.

	   default
	       Use the encoder default.

	   picture
	       Digital picture, like portrait, inner shot

	   photo
	       Outdoor photograph, with natural lighting

	   drawing
	       Hand or line drawing, with high-contrast details

	   icon
	       Small-sized colorful images

	   text
	       Text-like

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

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

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

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

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

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

       Supported Pixel Formats

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

       Options

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

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

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

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

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

       qmax (qpmax)
	   Maximum quantizer scale.

       qdiff (qpstep)
	   Maximum difference between quantizer scales.

       qblur (qblur)
	   Quantizer curve blur

       qcomp (qcomp)
	   Quantizer curve compression factor

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

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

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

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

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

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

	   hex (hex)
	       Hexagonal search with radius 2.

	   umh (umh)
	       Uneven multi-hexagon search.

	   esa (esa)
	       Exhaustive search.

	   tesa (tesa)
	       Hadamard exhaustive search (slowest).

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

       subq (subme)
	   Sub-pixel motion estimation method.

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

       keyint_min (min-keyint)
	   Minimum GOP size.

       coder
	   Set entropy encoder. Possible values:

	   ac  Enable CABAC.

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

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

	   chroma
	       Enable chroma in motion estimation.

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

       threads (threads)
	   Number of encoding threads.

       thread_type
	   Set multithreading technique. Possible values:

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

	   frame
	       Frame-based multithreading.

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

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

       tune (tune)
	   Set tuning of the encoding params.

       profile (profile)
	   Set profile restrictions.

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

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

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

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

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

	   none (0)
	       Disabled.

	   variance (1)
	       Variance AQ (complexity mask).

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

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

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

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

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

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

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

	   none (0)
	       Disabled

	   simple (1)
	       Enable only weighted refs

	   smart (2)
	       Enable both weighted refs and duplicates

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

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

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

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

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

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

	   none (none)
	       Disabled.

	   strict (strict)
	       Strictly hierarchical pyramid.

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

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

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

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

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

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

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

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

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

	   p8x8
	       8x8 P-frame partition.

	   p4x4
	       4x4 P-frame partition.

	   b8x8
	       4x4 B-frame partition.

	   i8x8
	       8x8 I-frame partition.

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

	   none (none)
	       Do not consider any partitions.

	   all (all)
	       Consider every partition.

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

	   none (none)
	       Disable MV prediction.

	   spatial (spatial)
	       Enable spatial predicting.

	   temporal (temporal)
	       Enable temporal predicting.

	   auto (auto)
	       Automatically decided.

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

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

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

	   none (none)
	       Disable HRD information signaling.

	   vbr (vbr)
	       Variable bit rate.

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

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

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

	   For example to specify libx264 encoding options with ffmpeg:

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

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

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

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

	   For example to specify libx264 encoding options with ffmpeg:

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

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

   libx265
       x265 H.265/HEVC encoder wrapper.

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

       Options

       preset
	   Set the x265 preset.

       tune
	   Set the x265 tune parameter.

       profile
	   Set profile restrictions.

       crf Set the quality for constant quality mode.

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

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

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

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

   libxvid
       Xvid MPEG-4 Part 2 encoder wrapper.

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

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

       Options

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

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

	   mv4 Use four motion vector by macroblock.

	   aic Enable high quality AC prediction.

	   gray
	       Only encode grayscale.

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

	   qpel
	       Enable quarter-pixel motion compensation.

	   cgop
	       Enable closed GOP.

	   global_header
	       Place global headers in extradata instead of every keyframe.

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

	   zero
	       Use no motion estimation (default).

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

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

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

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

	   simple
	       Use macroblock comparing function algorithm (default).

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

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

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

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

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

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

	   off Disable displaying of SSIM information.

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

		       Average SSIM: %f

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

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

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

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

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

   mpeg2
       MPEG-2 video encoder.

       Options

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

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

	   0
	   never
	       Never write it.

	   1
	   always
	       Always write it.

       video_format integer
	   Specifies the video_format written into the sequence display
	   extension indicating the source of the video pictures. The default
	   is unspecified, can be component, pal, ntsc, secam or mac.  For
	   maximum compatibility, use component.

   png
       PNG image encoder.

       Private options

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

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

   ProRes
       Apple ProRes encoder.

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

       Private Options for prores-ks

       profile integer
	   Select the ProRes profile to encode

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

	   auto
	   default
	   proxy
	   lt
	   standard
	   hq

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

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

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

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

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

       Speed considerations

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

       Setting a higher bits_per_mb limit will improve the speed.

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

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

       The ratecontrol method is selected as follows:

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

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

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

	   -   ICQ -- intelligent constant quality otherwise.

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

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

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

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

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

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

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

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

       ·   g/gop_size -> GopPicSize

       ·   bf/max_b_frames+1 -> GopRefDist

       ·   rc_init_occupancy/rc_initial_buffer_occupancy -> InitialDelayInKB

       ·   slices -> NumSlice

       ·   refs -> NumRefFrame

       ·   b_strategy/b_frame_strategy -> BRefType

       ·   cgop/CLOSED_GOP codec flag -> GopOptFlag

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

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

   snow
       Options

       iterative_dia_size
	   dia size for the iterative motion estimation

   VAAPI encoders
       Wrappers for hardware encoders accessible via VAAPI.

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

       The following standard libavcodec options are used:

       ·   g / gop_size

       ·   bf / max_b_frames

       ·   profile

       ·   level

       ·   b / bit_rate

       ·   maxrate / rc_max_rate

       ·   bufsize / rc_buffer_size

       ·   rc_init_occupancy / rc_initial_buffer_occupancy

       ·   compression_level

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

       ·   q / global_quality

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

       ·   qmin (only: qmax is not supported)

       ·   i_qfactor / i_quant_factor

       ·   i_qoffset / i_quant_offset

       ·   b_qfactor / b_quant_factor

       ·   b_qoffset / b_quant_offset

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

	   low_power
	       Use low-power encoding mode.

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

	       ac
	       cabac
		   Use CABAC.

	       vlc
	       cavlc
		   Use CAVLC.

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

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

       mpeg2_vaapi
	   profile and level set the value of profile_and_level_indication.

	   No rate control is supported.

       vp8_vaapi
	   B-frames are not supported.

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

	   loop_filter_level
	   loop_filter_sharpness
	       Manually set the loop filter parameters.

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

	   loop_filter_level
	   loop_filter_sharpness
	       Manually set the loop filter parameters.

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

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

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

       Options

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

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

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

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

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

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

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

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

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

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

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

       Options

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

	   By default, this work-around is disabled.

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

AUTHORS
       The FFmpeg developers.

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

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

							      FFMPEG-CODECS(1)
