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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 de-
coding 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 toler-
ance specifies how far ratecontrol is willing to deviate from the tar-
get average bitrate value. This is not related to min/max bitrate. Low-
ering 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).

qpelUse 1/4 pel motion compensation.

loopUse loop filter.

qscale
Use fixed qscale.

pass1
Use internal 2pass ratecontrol in first pass mode.

pass2
Use internal 2pass ratecontrol in second pass mode.

grayOnly decode/encode grayscale.

psnrSet error[?] variables during encoding.

truncated
Input bitstream might be randomly truncated.

drop_changed
Don't output frames whose parameters differ from first decoded
frame in stream. Error AVERROR_INPUT_CHANGED is returned when a
frame is dropped.

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 repro-
ducible and match between platforms. Its primary use is for regres-
sion testing.

aic Apply H263 advanced intra coding / mpeg4 ac prediction.

ilmeApply interlaced motion estimation.

cgopUse closed gop.

output_corrupt
Output even potentially corrupted frames.

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_VARI-
ABLE_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 dis-
abled. If a value of -1 is used, it will choose an automatic value de-
pending on the encoder.

Default value is 0.

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

codec_tag integer
bug flags (decoding,video)
Workaround not auto detected encoder bugs.

Possible values:

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

ump4(autodetected if fourcc==UMP4)

no_padding
padding bug (autodetected)

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

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

edgeedge padding bug (autodetected per fourcc/version)

hpel_chroma
dc_clip
ms Workaround various bugs in microsoft broken decoders.

trunc
trancated frames

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

Possible values:

verystrictly 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 con-
sequences

normal
unofficial
allow unofficial extensions

experimental
allow non standardized experimental things, experimental (unfin-
ished/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
rc_override_count integer
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).

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.

dct integer (encoding,video)
Set DCT algorithm.

Possible values:

autoautoselect a good one (default)

fastint
fast integer

int accurate integer

mmx
altivec
faanfloating 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
xvid
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
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:

pictpicture 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

mmcomemory management control operations (H.264)

bugs
buffers
picture buffer allocations

thread_ops
threading operations

nomcskip 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

satdsum of absolute Hadamard transformed differences

dct sum of absolute DCT transformed differences

psnrsum of squared quantization errors (avoid, low quality)

bit number of bits needed for the block

rd rate distortion optimal, slow

zero0

vsadsum of absolute vertical differences

vssesum of squared vertical differences

nssenoise 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

satdsum of absolute Hadamard transformed differences

dct sum of absolute DCT transformed differences

psnrsum of squared quantization errors (avoid, low quality)

bit number of bits needed for the block

rd rate distortion optimal, slow

zero0

vsadsum of absolute vertical differences

vssesum of squared vertical differences

nssenoise 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

satdsum of absolute Hadamard transformed differences

dct sum of absolute DCT transformed differences

psnrsum of squared quantization errors (avoid, low quality)

bit number of bits needed for the block

rd rate distortion optimal, slow

zero0

vsadsum of absolute vertical differences

vssesum of squared vertical differences

nssenoise 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

satdsum of absolute Hadamard transformed differences

dct sum of absolute DCT transformed differences

psnrsum of squared quantization errors (avoid, low quality)

bit number of bits needed for the block

rd rate distortion optimal, slow

zero0

vsadsum of absolute vertical differences

vssesum of squared vertical differences

nssenoise 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.

(1024, INT_MAX)
full motion estimation(slowest)

(768, 1024]
umh motion estimation

(512, 768]
hex motion estimation

(256, 512]
l2s diamond motion estimation

[2,256]
var diamond motion estimation

(-1, 2)
small diamond motion estimation

-1 funny diamond motion estimation

(INT_MIN, -1)
sab diamond motion estimation

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

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

Possible values:

sad sum of absolute differences, fast (default)

sse sum of squared errors

satdsum of absolute Hadamard transformed differences

dct sum of absolute DCT transformed differences

psnrsum of squared quantization errors (avoid, low quality)

bit number of bits needed for the block

rd rate distortion optimal, slow

zero0

vsadsum of absolute vertical differences

vssesum of squared vertical differences

nssenoise 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.

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

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

Possible values:

simple
use mbcmp (default)

bitsuse fewest bits

rd use best rate distortion

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

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

fastAllow non spec compliant speedup tricks.

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.

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

skip_manual
Do not skip samples and export skip information as frame side data.

ass_ro_flush_noop
Do not reset ASS ReadOrder field on flush.

icc_profiles
Generate/parse embedded ICC profiles from/to colorimetry tags.

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

mvs Export motion vectors into frame side-data (see "AV_FRAME_DATA_MO-
TION_VECTORS") for codecs that support it. See also doc/exam-
ples/export_mvs.c.

prftExport encoder Producer Reference Time into packet side-data (see
"AV_PKT_DATA_PRFT") for codecs that support it.

venc_params
Export video encoding parameters through frame side data (see
"AV_FRAME_DATA_VIDEO_ENC_PARAMS") for codecs that support it. At
present, those are H.264 and VP9.

film_grain
Export film grain parameters through frame side data (see
"AV_FRAME_DATA_FILM_GRAIN_PARAMS"). Supported at present by AV1
decoders.

enhancements
Export picture enhancement metadata through frame side data, e.g.
LCEVC (see "AV_FRAME_DATA_LCEVC").

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

Possible values:

auto, 0
automatically select the number of threads to set

Default value is auto.

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)
Set encoder codec profile. Default value is unknown. Encoder specific
profiles are documented in the relevant encoder documentation.

level integer (encoding,audio,video)
Set the encoder level. This level depends on the specific codec, and
might correspond to the profile level. It is set by default to unknown.

Possible values:

unknown

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

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

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

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:

noneDiscard 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.

nointra
Discard all frames except I frames.

all Discard all frames.

Default value is default.

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

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

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

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

mv0_threshold integer (encoding,video)
compression_level integer (encoding,audio,video)
bits_per_raw_sample integer
channel_layout integer (decoding/encoding,audio)
See the Channel Layout section in the ffmpeg-utils(1) manual for the
required syntax.

rc_max_vbv_use float (encoding,video)
rc_min_vbv_use float (encoding,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

filmFilm

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

chroma-derived-nc
Chroma-derived NCL

chroma-derived-c
Chroma-derived CL

ictcp
ICtCp

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
limited
MPEG (219*2^(n-8))

pc
jpeg
fullJPEG (2^n-1)

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

left
center
topleft
top
bottomleft
bottom

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

premultiplied
straight

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 in-
stead 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 new-
lines and indentation:

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 mul-
timedia 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-de-
coders" 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.

av1
AOMedia Video 1 (AV1) decoder.

Options

operating_point
Select an operating point of a scalable AV1 bitstream (0 - 31). Default
is 0.

hevc
HEVC (AKA ITU-T H.265 or ISO/IEC 23008-2) decoder.

The decoder supports MV-HEVC multiview streams with at most two views.
Views to be output are selected by supplying a list of view IDs to the de-
coder (the view_ids option). This option may be set either statically be-
fore decoder init, or from the get_format() callback - useful for the case
when the view count or IDs change dynamically during decoding.

Only the base layer is decoded by default.

Note that if you are using the "ffmpeg" CLI tool, you should be using view
specifiers as documented in its manual, rather than the options documented
here.

Options

view_ids (MV-HEVC)
Specify a list of view IDs that should be output. This option can also
be set to a single '-1', which will cause all views defined in the VPS
to be decoded and output.

view_ids_available (MV-HEVC)
This option may be read by the caller to retrieve an array of view IDs
available in the active VPS. The array is empty for single-layer video.

The value of this option is guaranteed to be accurate when read from
the get_format() callback. It may also be set at other times (e.g. af-
ter opening the decoder), but the value is informational only and may
be incorrect (e.g. when the stream contains multiple distinct VPS
NALUs).

view_pos_available (MV-HEVC)
This option may be read by the caller to retrieve an array of view po-
sitions (left, right, or unspecified) available in the active VPS, as
"AVStereo3DView" values. When the array is available, its elements ap-
ply to the corresponding elements of view_ids_available, i.e.
"view_pos_available[i]" contains the position of view with ID
"view_ids_available[i]".

Same validity restrictions as for view_ids_available apply to this op-
tion.

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

libdav1d
dav1d AV1 decoder.

libdav1d allows libavcodec to decode the AOMedia Video 1 (AV1) codec. Re-
quires the presence of the libdav1d headers and library during configura-
tion. You need to explicitly configure the build with "--enable-libdav1d".

Options

The following options are supported by the libdav1d wrapper.

max_frame_delay
Set max amount of frames the decoder may buffer internally. The default
value is 0 (autodetect).

filmgrain
Apply film grain to the decoded video if present in the bitstream. De-
faults to the internal default of the library. This option is depre-
cated and will be removed in the future. See the global option "ex-
port_side_data" to export Film Grain parameters instead of applying it.

oppoint
Select an operating point of a scalable AV1 bitstream (0 - 31). De-
faults to the internal default of the library.

alllayers
Output all spatial layers of a scalable AV1 bitstream. The default
value is false.

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

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

libuavs3d
AVS3-P2/IEEE1857.10 video decoder.

libuavs3d allows libavcodec to decode AVS3 streams. Requires the presence
of the libuavs3d headers and library during configuration. You need to ex-
plicitly configure the build with "--enable-libuavs3d".

Options

The following option is supported by the libuavs3d wrapper.

frame_threads
Set amount of frame threads to use during decoding. The default value
is 0 (autodetect).

libxevd
eXtra-fast Essential Video Decoder (XEVD) MPEG-5 EVC decoder wrapper.

This decoder requires the presence of the libxevd headers and library dur-
ing configuration. You need to explicitly configure the build with --en-
able-libxevd.

The xevd project website is at <https://github.com/mpeg5/xevd>.

Options

The following options are supported by the libxevd wrapper. The
xevd-equivalent options or values are listed in parentheses for easy migra-
tion.

To get a more accurate and extensive documentation of the libxevd options,
invoke the command "xevd_app --help" or consult the libxevd documentation.

threads (threads)
Force to use a specific number of threads

QSV Decoders
The family of Intel QuickSync Video decoders (VC1, MPEG-2, H.264, HEVC,
JPEG/MJPEG, VP8, VP9, AV1, VVC).

Common Options

The following options are supported by all qsv decoders.

async_depth
Internal parallelization depth, the higher the value the higher the la-
tency.

gpu_copy
A GPU-accelerated copy between video and system memory

default
on
off

HEVC Options

Extra options for hevc_qsv.

load_plugin
A user plugin to load in an internal session

none
hevc_sw
hevc_hw

load_plugins
A :-separate list of hexadecimal plugin UIDs to load in an internal
session

v210
Uncompressed 4:2:2 10-bit decoder.

Options

custom_stride
Set the line size of the v210 data in bytes. The default value is 0
(autodetect). You can use the special -1 value for a strideless v210 as
seen in BOXX files.

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. The default
value is 1. 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 val-
ues (like the default value). This option makes it possible to decode
such streams correctly by using lavc's old buggy lpc logic for decod-
ing.

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 pub-
licly 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 "--en-
able-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 dur-
ing configuration. You need to explicitly configure the build with "--en-
able-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).

libmpeghdec
libmpeghdec decoder wrapper.

libmpeghdec allows libmpeghdec to decode the MPEG-H 3D audio codec. Re-
quires the presence of the libmpeghdec headers and library during configu-
ration. You need to explicitly configure the build with "--enable-libm-
peghdec --enable-nonfree".

libopencore-amrnb
libopencore-amrnb decoder wrapper.

libopencore-amrnb allows libavcodec to decode the Adaptive Multi-Rate Nar-
rowband audio codec. Using it requires the presence of the libopencore-am-
rnb headers and library during configuration. You need to explicitly con-
figure 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 Wide-
band 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. Re-
quires the presence of the libopus headers and library during configura-
tion. 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
libaribb24
ARIB STD-B24 caption decoder.

Implements profiles A and C of the ARIB STD-B24 standard.

libaribb24 Decoder Options

-aribb24-base-path path
Sets the base path for the libaribb24 library. This is utilized for
reading of configuration files (for custom unicode conversions), and
for dumping of non-text symbols as images under that location.

Unset by default.

-aribb24-skip-ruby-text boolean
Tells the decoder wrapper to skip text blocks that contain half-height
ruby text.

Enabled by default.

libaribcaption
Yet another ARIB STD-B24 caption decoder using external libaribcaption li-
brary.

Implements profiles A and C of the Japanese ARIB STD-B24 standard, Brazil-
ian ABNT NBR 15606-1, and Philippines version of ISDB-T.

Requires the presence of the libaribcaption headers and library
(<https://github.com/xqq/libaribcaption>) during configuration. You need
to explicitly configure the build with "--enable-libaribcaption". If both
libaribb24 and libaribcaption are enabled, libaribcaption decoder precedes.

libaribcaption Decoder Options

-sub_type subtitle_type
Specifies the format of the decoded subtitles.

bitmap
Graphical image.

ass ASS formatted text.

textSimple text based output without formatting.

The default is ass as same as libaribb24 decoder. Some present players
(e.g., mpv) expect ASS format for ARIB caption.

-caption_encoding encoding_scheme
Specifies the encoding scheme of input subtitle text.

autoAutomatically detect text encoding (default).

jis 8bit-char JIS encoding defined in ARIB STD B24. This encoding used
in Japan for ISDB captions.

utf8UTF-8 encoding defined in ARIB STD B24. This encoding is used in
Philippines for ISDB-T captions.

latin
Latin character encoding defined in ABNT NBR 15606-1. This encod-
ing is used in South America for SBTVD / ISDB-Tb captions.

-font font_name[,font_name2,...]
Specify comma-separated list of font family names to be used for bitmap
or ass type subtitle rendering. Only first font name is used for ass
type subtitle.

If not specified, use internally defined default font family.

-ass_single_rect boolean
ARIB STD-B24 specifies that some captions may be displayed at different
positions at a time (multi-rectangle subtitle). Since some players
(e.g., old mpv) can't handle multiple ASS rectangles in a single AVSub-
title, or multiple ASS rectangles of indeterminate duration with the
same start timestamp, this option can change the behavior so that all
the texts are displayed in a single ASS rectangle.

The default is false.

If your player cannot handle AVSubtitles with multiple ASS rectangles
properly, set this option to true or define ASS_SINGLE_RECT=1 to change
default behavior at compilation.

-force_outline_text boolean
Specify whether always render outline text for all characters regard-
less of the indication by character style.

The default is false.

-outline_width number (0.0 - 3.0)
Specify width for outline text, in dots (relative).

The default is 1.5.

-ignore_background boolean
Specify whether to ignore background color rendering.

The default is false.

-ignore_ruby boolean
Specify whether to ignore rendering for ruby-like (furigana) charac-
ters.

The default is false.

-replace_drcs boolean
Specify whether to render replaced DRCS characters as Unicode charac-
ters.

The default is true.

-replace_msz_ascii boolean
Specify whether to replace MSZ (Middle Size; half width) fullwidth al-
phanumerics with halfwidth alphanumerics.

The default is true.

-replace_msz_japanese boolean
Specify whether to replace some MSZ (Middle Size; half width) fullwidth
japanese special characters with halfwidth ones.

The default is true.

-replace_msz_glyph boolean
Specify whether to replace MSZ (Middle Size; half width) characters
with halfwidth glyphs if the fonts supports it. This option works un-
der FreeType or DirectWrite renderer with Adobe-Japan1 compliant fonts.
e.g., IBM Plex Sans JP, Morisawa BIZ UDGothic, Morisawa BIZ UDMincho,
Yu Gothic, Yu Mincho, and Meiryo.

The default is true.

-canvas_size image_size
Specify the resolution of the canvas to render subtitles to; usually,
this should be frame size of input video. This only applies when
"-subtitle_type" is set to bitmap.

The libaribcaption decoder assumes input frame size for bitmap render-
ing as below:

1. PROFILE_A : 1440 x 1080 with SAR (PAR) 4:3

2. PROFILE_C : 320 x 180 with SAR (PAR) 1:1

If actual frame size of input video does not match above assumption,
the rendered captions may be distorted. To make the captions undis-
torted, add "-canvas_size" option to specify actual input video size.

Note that the "-canvas_size" option is not required for video with dif-
ferent size but same aspect ratio. In such cases, the caption will be
stretched or shrunk to actual video size if "-canvas_size" option is
not specified. If "-canvas_size" option is specified with different
size, the caption will be stretched or shrunk as specified size with
calculated SAR.

libaribcaption decoder usage examples

Display MPEG-TS file with ARIB subtitle by "ffplay" tool:

ffplay -sub_type bitmap MPEG.TS

Display MPEG-TS file with input frame size 1920x1080 by "ffplay" tool:

ffplay -sub_type bitmap -canvas_size 1920x1080 MPEG.TS

Embed ARIB subtitle in transcoded video:

ffmpeg -sub_type bitmap -i src.m2t -filter_complex "[0:v][0:s]overlay" -vcodec h264 dest.mp4

dvbsub
Options

compute_clut
-2 Compute clut once if no matching CLUT is in the stream.

-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 Vob-
Sub. 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 hexadeci-
mal numbers (without 0x prefix) separated by commas, 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. (ex-
perimental)

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 "--en-
able-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_default_region
Set default character set used for decoding, a value between 0 and 87
(see ETS 300 706, Section 15, Table 32). Default value is -1, which
does not override the libzvbi default. This option is needed for some
legacy level 1.0 transmissions which cannot signal the proper charset.

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

txt_format
Specifies the format of the decoded subtitles.

bitmap
The default format, you should use this for teletext pages, because
certain graphics and colors cannot be expressed in simple text or
even ASS.

textSimple text based output without formatting.

ass Formatted ASS output, subtitle pages and teletext pages are re-
turned in different styles, subtitle pages are stripped down to
text, but an effort is made to keep the text alignment and the for-
matting.

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 gen-
erated 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 dou-
ble-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 mul-
timedia 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-en-
coders" 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.

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 dynami-
cally 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 is the default 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.

anmrAverage 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.

fastConstant 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.

aac_ms
Sets mid/side coding mode. The default value of "auto" will automati-
cally 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 fre-
quency 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 arti-
facts 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. Use in
conjunction with -ar to decrease the samplerate.

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.

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.

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 ac3_fixed encoder is not the default codec for any of the out-
put 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 au-
dio, 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 doc-
uments.

*<<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/Pro-
fessional/18_Metadata.Guide.pdf>>
*<<http://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Pro-
fessional/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 writ-
ten to the bitstream if a center channel is present. The value is spec-
ified 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 bit-
stream.

-mixing_level number
Mixing Level. Specifies peak sound pressure level (SPL) in the produc-
tion 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 ses-
sion 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 de-
fault 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 au-
dio.

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 aver-
age volume of the dialogue to a preset level. The goal is to match vol-
ume level between program sources. A value of -31dB will result in no
volume level change, relative to the source volume, during audio repro-
duction. 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 en-
coder 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 Alter-
nate 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 down-
mix mode.

0
notindicated
Not Indicated (default)

1
ltrtLt/Rt Downmix Preferred

2
loroLo/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 Sur-
round EX (7.1 matrixed to 5.1). Using this option does NOT mean the en-
coder 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 Head-
phone 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
hdcdHDCD A/D Converter

Other AC-3 Encoding Options

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

cutoff frequency
Set lowpass cutoff frequency. If unspecified, the encoder selects a de-
fault 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 ex-
ist 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 fre-
quency 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 frequen-
cies. 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
autoSelected 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 dis-
abled.

-1
autoSelected 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 op-
tions 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

noneLPC 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

autoThe 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 algo-
rithm 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, it's in de-
velopment 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 An-
droid project.

Requires the presence of the libfdk-aac headers and library during configu-
ration. You need to explicitly configure the build with "--en-
able-libfdk-aac". The library is also incompatible with GPL, so if you al-
low the use of GPL, you should configure with "--enable-gpl --enable-non-
free --enable-libfdk-aac".

This encoder has support for the AAC-HE profiles.

VBR encoding, enabled through the vbr or flags +qscale options, is experi-
mental 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://source-
forge.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 pro-
file.

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 im-
proves 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.

eld_v2
Enable ELDv2 (LD-MPS extension for ELD stereo signals) for ELDv2 if set
to 1, disabled if set to 0.

Note that option is available when fdk-aac version (AACEN-
CODER_LIB_VL0.AACENCODER_LIB_VL1.AACENCODER_LIB_VL2) > (4.0.0).

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, im-
plicit 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.

latmOutput 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.

frame_length
Set the audio frame length in samples. Default value is the internal
default of the library. Refer to the library's documentation for infor-
mation about supported values.

Examples

* Use ffmpeg to convert an audio file to VBR AAC in an M4A (MP4) con-
tainer:

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

liblc3
liblc3 LC3 (Low Complexity Communication Codec) encoder wrapper.

Requires the presence of the liblc3 headers and library during configura-
tion. You need to explicitly configure the build with "--enable-liblc3".

This encoder has support for the Bluetooth SIG LC3 codec for the LE Audio
protocol, and the following features of LC3plus:

* Frame duration of 2.5 and 5ms.

* High-Resolution mode, 48 KHz, and 96 kHz sampling rates.

For more information see the liblc3 project at
<https://github.com/google/liblc3>.

Options

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

b bitrate
Set the bit rate in bits/s. This will determine the fixed size of the
encoded frames, for a selected frame duration.

ar frequency
Set the audio sampling rate (in Hz).

channels
Set the number of audio channels.

frame_duration
Set the audio frame duration in milliseconds. Default value is 10ms.
Allowed frame durations are 2.5ms, 5ms, 7.5ms and 10ms. LC3 (Bluetooth
LE Audio), allows 7.5ms and 10ms; and LC3plus 2.5ms, 5ms and 10ms.

The 10ms frame duration is available in LC3 and LC3 plus standard. In
this mode, the produced bitstream can be referenced either as LC3 or
LC3plus.

high_resolution boolean
Enable the high-resolution mode if set to 1. The high-resolution mode
is available with all LC3plus frame durations and for a sampling rate
of 48 KHz, and 96 KHz.

The encoder automatically turns off this mode at lower sampling rates
and activates it at 96 KHz.

This mode should be preferred at high bitrates. In this mode, the audio
bandwidth is always up to the Nyquist frequency, compared to LC3 at 48
KHz, which limits the bandwidth to 20 KHz.

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

Requires the presence of the libmp3lame headers and library during configu-
ration. You need to explicitly configure the build with "--en-
able-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 ex-
pressed 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.

original (-o)
Set MPEG audio original flag when set to 1. The default value is 1 (en-
abled).

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 "--en-
able-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 sup-
ported, 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 configura-
tion. 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 parenthe-
ses.

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 ar-
gument 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.

fec (n/a)
Enable inband forward error correction. packet_loss must be non-zero to
take advantage - frequency of FEC 'side-data' is proportional to ex-
pected packet loss. Default is disabled.

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

voipFavor improved speech intelligibility.

audio
Favor faithfulness to the input (the default).

lowdelay
Restrict to only the lowest delay modes by disabling voice-opti-
mized 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 narrow-
band, mediumband, wideband, super wideband, and fullband respectively.
The default is 0 (cutoff disabled). Note that libopus forces a wideband
cutoff for bitrates < 15 kbps, unless CELT-only (application set to
lowdelay) mode is used.

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 optimizations 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, ac-
cording 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://source-
forge.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 configura-
tion. You need to explicitly configure the build with "--enable-libshine".

See also libmp3lame.

Options

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

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

libtwolame
TwoLAME MP2 encoder wrapper.

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

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 com-
mand-line tool. For library interface users, use global_quality.

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

autoChoose mode automatically based on the input. This is the default.

stereo
Stereo

joint_stereo
Joint stereo

dual_channel
Dual channel

monoMono

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 (dis-
abled).

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 con-
figuration. You need to explicitly configure the build with "--en-
able-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, oth-
erwise 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 con-
figuration. You need to explicitly configure the build with "--enable-lib-
vorbis".

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 op-
tions, 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 num-
ber 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 li-
brary 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 re-
lated option is expressed in kHz. The default value is 0 (cutoff dis-
abled).

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.

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.

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 gen-
eral 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/wav-
packenc.c.

compression_level (-f, -h, -hh, and -x)

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.

autoLet the encoder decide automatically.

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

on enabled

off disabled

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

a64_multi, a64_multi5
A64 / Commodore 64 multicolor charset encoder. "a64_multi5" is extended
with 5th color (colram).

Cinepak
Cinepak aka CVID encoder. Compatible with Windows 3.1 and vintage MacOS.

Options

g integer
Keyframe interval. A keyframe is inserted at least every "-g" frames,
sometimes sooner.

q:v integer
Quality factor. Lower is better. Higher gives lower bitrate. The fol-
lowing table lists bitrates when encoding akiyo_cif.y4m for various
values of "-q:v" with "-g 100":

"-q:v 1" 1918 kb/s
"-q:v 2" 1735 kb/s
"-q:v 4" 1500 kb/s
"-q:v 10" 1041 kb/s
"-q:v 20" 826 kb/s
"-q:v 40" 553 kb/s
"-q:v 100" 394 kb/s
"-q:v 200" 312 kb/s
"-q:v 400" 266 kb/s
"-q:v 1000" 237 kb/s

max_extra_cb_iterations integer
Max extra codebook recalculation passes, more is better and slower.

skip_empty_cb boolean
Avoid wasting bytes, ignore vintage MacOS decoder.

max_strips integer
min_strips integer
The minimum and maximum number of strips to use. Wider range sometimes
improves quality. More strips is generally better quality but costs
more bits. Fewer strips tend to yield more keyframes. Vintage compat-
ible is 1..3.

strip_number_adaptivity integer
How much number of strips is allowed to change between frames. Higher
is better but slower.

ffv1
FFv1 Encoder

Options

The following options are supported by FFmpeg's FFv1 encoder.

context
Sets the context size, 0 (default) is small, 1 is big.

coder
Set the coder,

riceGolomb rice coder

range_def
Range coder with default table

range_tab
Range coder with custom table

slicecrc
-1 (default, automatic), 1 use crc with zero initial and final state, 2
use crc with non zero initial and final state

qtable
default
default, automatic

8bituse 8bit default

greater8bit
use >8bit default

remap_optimizer
0 - 5, default 3, how much effort the encoder puts into optimizing the
remap table.

GIF
GIF image/animation encoder.

Options

gifflags integer
Sets the flags used for GIF encoding.

offsetting
Enables picture offsetting.

Default is enabled.

transdiff
Enables transparency detection between frames.

Default is enabled.

gifimage integer
Enables encoding one full GIF image per frame, rather than an animated
GIF.

Default value is 0.

global_palette integer
Writes a palette to the global GIF header where feasible.

If disabled, every frame will always have a palette written, even if
there is a global palette supplied.

Default value is 1.

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

tile_width integer
Sets tile width. Range is 1 to 1073741824. Default is 256.

tile_height integer
Sets tile height. Range is 1 to 1073741824. Default is 256.

pred integer
Allows setting the discrete wavelet transform (DWT) type

dwt97int (Lossy)
dwt53 (Lossless)

Default is "dwt97int"

sop boolean
Enable this to add SOP marker at the start of each packet. Disabled by
default.

eph boolean
Enable this to add EPH marker at the end of each packet header. Dis-
abled by default.

prog integer
Sets the progression order to be used by the encoder. Possible values
are:

lrcp
rlcp
rpcl
pcrl
cprl

Set to "lrcp" by default.

layer_rates string
By default, when this option is not used, compression is done using the
quality metric. This option allows for compression using compression
ratio. The compression ratio for each level could be specified. The
compression ratio of a layer "l" species the what ratio of total file
size is contained in the first "l" layers.

Example usage:

ffmpeg -i input.bmp -c:v jpeg2000 -layer_rates "100,10,1" output.j2k

This would compress the image to contain 3 layers, where the data con-
tained in the first layer would be compressed by 1000 times, compressed
by 100 in the first two layers, and shall contain all data while using
all 3 layers.

librav1e
rav1e AV1 encoder wrapper.

Requires the presence of the rav1e headers and library during configura-
tion. You need to explicitly configure the build with "--enable-librav1e".

Options

qmaxSets the maximum quantizer to use when using bitrate mode.

qminSets the minimum quantizer to use when using bitrate mode.

qp Uses quantizer mode to encode at the given quantizer (0-255).

speed
Selects the speed preset (0-10) to encode with.

tiles
Selects how many tiles to encode with.

tile-rows
Selects how many rows of tiles to encode with.

tile-columns
Selects how many columns of tiles to encode with.

rav1e-params
Set rav1e options using a list of key=value pairs separated by ":". See
rav1e --help for a list of options.

For example to specify librav1e encoding options with -rav1e-params:

ffmpeg -i input -c:v librav1e -b:v 500K -rav1e-params speed=5:low_latency=true output.mp4

libaom-av1
libaom AV1 encoder wrapper.

Requires the presence of the libaom headers and library during configura-
tion. You need to explicitly configure the build with "--enable-libaom".

Options

The wrapper supports the following standard libavcodec options:

b Set bitrate target in bits/second. By default this will use vari-
able-bitrate mode. If maxrate and minrate are also set to the same
value then it will use constant-bitrate mode, otherwise if crf is set
as well then it will use constrained-quality mode.

g keyint_min
Set key frame placement. The GOP size sets the maximum distance be-
tween key frames; if zero the output stream will be intra-only. The
minimum distance is ignored unless it is the same as the GOP size, in
which case key frames will always appear at a fixed interval. Not set
by default, so without this option the library has completely free
choice about where to place key frames.

qmin qmax
Set minimum/maximum quantisation values. Valid range is from 0 to 63
(warning: this does not match the quantiser values actually used by AV1
- divide by four to map real quantiser values to this range). Defaults
to min/max (no constraint).

minrate maxrate bufsize rc_init_occupancy
Set rate control buffering parameters. Not used if not set - defaults
to unconstrained variable bitrate.

threads
Set the number of threads to use while encoding. This may require the
tiles or row-mt options to also be set to actually use the specified
number of threads fully. Defaults to the number of hardware threads
supported by the host machine.

profile
Set the encoding profile. Defaults to using the profile which matches
the bit depth and chroma subsampling of the input.

The wrapper also has some specific options:

cpu-used
Set the quality/encoding speed tradeoff. Valid range is from 0 to 8,
higher numbers indicating greater speed and lower quality. The default
value is 1, which will be slow and high quality.

auto-alt-ref
Enable use of alternate reference frames. Defaults to the internal de-
fault of the library.

arnr-max-frames (frames)
Set altref noise reduction max frame count. Default is -1.

arnr-strength (strength)
Set altref noise reduction filter strength. Range is -1 to 6. Default
is -1.

aq-mode (aq-mode)
Set adaptive quantization mode. Possible values:

none (0)
Disabled.

variance (1)
Variance-based.

complexity (2)
Complexity-based.

cyclic (3)
Cyclic refresh.

tune (tune)
Set the distortion metric the encoder is tuned with. Default is "psnr".

psnr (0)
ssim (1)

lag-in-frames
Set the maximum number of frames which the encoder may keep in flight
at any one time for lookahead purposes. Defaults to the internal de-
fault of the library.

error-resilience
Enable error resilience features:

default
Improve resilience against losses of whole frames.

Not enabled by default.

crf Set the quality/size tradeoff for constant-quality (no bitrate target)
and constrained-quality (with maximum bitrate target) modes. Valid
range is 0 to 63, higher numbers indicating lower quality and smaller
output size. Only used if set; by default only the bitrate target is
used.

static-thresh
Set a change threshold on blocks below which they will be skipped by
the encoder. Defined in arbitrary units as a nonnegative integer, de-
faulting to zero (no blocks are skipped).

drop-threshold
Set a threshold for dropping frames when close to rate control bounds.
Defined as a percentage of the target buffer - when the rate control
buffer falls below this percentage, frames will be dropped until it has
refilled above the threshold. Defaults to zero (no frames are
dropped).

denoise-noise-level (level)
Amount of noise to be removed for grain synthesis. Grain synthesis is
disabled if this option is not set or set to 0.

denoise-block-size (pixels)
Block size used for denoising for grain synthesis. If not set, AV1
codec uses the default value of 32.

undershoot-pct (pct)
Set datarate undershoot (min) percentage of the target bitrate. Range
is -1 to 100. Default is -1.

overshoot-pct (pct)
Set datarate overshoot (max) percentage of the target bitrate. Range is
-1 to 1000. Default is -1.

minsection-pct (pct)
Minimum percentage variation of the GOP bitrate from the target bi-
trate. If minsection-pct is not set, the libaomenc wrapper computes it
as follows: "(minrate * 100 / bitrate)". Range is -1 to 100. Default
is -1 (unset).

maxsection-pct (pct)
Maximum percentage variation of the GOP bitrate from the target bi-
trate. If maxsection-pct is not set, the libaomenc wrapper computes it
as follows: "(maxrate * 100 / bitrate)". Range is -1 to 5000. Default
is -1 (unset).

frame-parallel (boolean)
Enable frame parallel decodability features. Default is true.

tiles
Set the number of tiles to encode the input video with, as columns x
rows. Larger numbers allow greater parallelism in both encoding and
decoding, but may decrease coding efficiency. Defaults to the minimum
number of tiles required by the size of the input video (this is 1x1
(that is, a single tile) for sizes up to and including 4K).

tile-columns tile-rows
Set the number of tiles as log2 of the number of tile rows and columns.
Provided for compatibility with libvpx/VP9.

row-mt (Requires libaom >= 1.0.0-759-g90a15f4f2)
Enable row based multi-threading. Disabled by default.

enable-cdef (boolean)
Enable Constrained Directional Enhancement Filter. The libaom-av1 en-
coder enables CDEF by default.

enable-restoration (boolean)
Enable Loop Restoration Filter. Default is true for libaom-av1.

enable-global-motion (boolean)
Enable the use of global motion for block prediction. Default is true.

enable-intrabc (boolean)
Enable block copy mode for intra block prediction. This mode is useful
for screen content. Default is true.

enable-rect-partitions (boolean) (Requires libaom >= v2.0.0)
Enable rectangular partitions. Default is true.

enable-1to4-partitions (boolean) (Requires libaom >= v2.0.0)
Enable 1:4/4:1 partitions. Default is true.

enable-ab-partitions (boolean) (Requires libaom >= v2.0.0)
Enable AB shape partitions. Default is true.

enable-angle-delta (boolean) (Requires libaom >= v2.0.0)
Enable angle delta intra prediction. Default is true.

enable-cfl-intra (boolean) (Requires libaom >= v2.0.0)
Enable chroma predicted from luma intra prediction. Default is true.

enable-filter-intra (boolean) (Requires libaom >= v2.0.0)
Enable filter intra predictor. Default is true.

enable-intra-edge-filter (boolean) (Requires libaom >= v2.0.0)
Enable intra edge filter. Default is true.

enable-smooth-intra (boolean) (Requires libaom >= v2.0.0)
Enable smooth intra prediction mode. Default is true.

enable-paeth-intra (boolean) (Requires libaom >= v2.0.0)
Enable paeth predictor in intra prediction. Default is true.

enable-palette (boolean) (Requires libaom >= v2.0.0)
Enable palette prediction mode. Default is true.

enable-flip-idtx (boolean) (Requires libaom >= v2.0.0)
Enable extended transform type, including FLIPADST_DCT, DCT_FLIPADST,
FLIPADST_FLIPADST, ADST_FLIPADST, FLIPADST_ADST, IDTX, V_DCT, H_DCT,
V_ADST, H_ADST, V_FLIPADST, H_FLIPADST. Default is true.

enable-tx64 (boolean) (Requires libaom >= v2.0.0)
Enable 64-pt transform. Default is true.

reduced-tx-type-set (boolean) (Requires libaom >= v2.0.0)
Use reduced set of transform types. Default is false.

use-intra-dct-only (boolean) (Requires libaom >= v2.0.0)
Use DCT only for INTRA modes. Default is false.

use-inter-dct-only (boolean) (Requires libaom >= v2.0.0)
Use DCT only for INTER modes. Default is false.

use-intra-default-tx-only (boolean) (Requires libaom >= v2.0.0)
Use Default-transform only for INTRA modes. Default is false.

enable-ref-frame-mvs (boolean) (Requires libaom >= v2.0.0)
Enable temporal mv prediction. Default is true.

enable-reduced-reference-set (boolean) (Requires libaom >= v2.0.0)
Use reduced set of single and compound references. Default is false.

enable-obmc (boolean) (Requires libaom >= v2.0.0)
Enable obmc. Default is true.

enable-dual-filter (boolean) (Requires libaom >= v2.0.0)
Enable dual filter. Default is true.

enable-diff-wtd-comp (boolean) (Requires libaom >= v2.0.0)
Enable difference-weighted compound. Default is true.

enable-dist-wtd-comp (boolean) (Requires libaom >= v2.0.0)
Enable distance-weighted compound. Default is true.

enable-onesided-comp (boolean) (Requires libaom >= v2.0.0)
Enable one sided compound. Default is true.

enable-interinter-wedge (boolean) (Requires libaom >= v2.0.0)
Enable interinter wedge compound. Default is true.

enable-interintra-wedge (boolean) (Requires libaom >= v2.0.0)
Enable interintra wedge compound. Default is true.

enable-masked-comp (boolean) (Requires libaom >= v2.0.0)
Enable masked compound. Default is true.

enable-interintra-comp (boolean) (Requires libaom >= v2.0.0)
Enable interintra compound. Default is true.

enable-smooth-interintra (boolean) (Requires libaom >= v2.0.0)
Enable smooth interintra mode. Default is true.

aom-params
Set libaom options using a list of key=value pairs separated by ":".
For a list of supported options, see aomenc --help under the section
"AV1 Specific Options".

For example to specify libaom encoding options with -aom-params:

ffmpeg -i input -c:v libaom-av1 -b:v 500K -aom-params tune=psnr:enable-tpl-model=1 output.mp4

liboapv
Advanced Professional Video codec encoder wrapper.

This encoder requires the presence of the liboapv headers and library dur-
ing configuration. You need to explicitly configure the build with --en-
able-liboapv.

Many liboapv encoder options are mapped to FFmpeg global codec options,
while unique encoder options are provided through private options.

The apv project website is at <https://github.com/AcademySoftwareFounda-
tion/openapv>.

Options

The following options are supported by the liboapv wrapper.

To get a more extensive documentation of the liboapv options, consult
the liboapv documentation.

preset
Set the quality-speed tradeoff [fastest, fast, medium, slow, placebo,
default]

qp Set the quantization parameter value for CQP rate control mode.

oapv-params (parse_apv_params)
Set liboapvenc options using a list of key=value pairs separated by
":". See the liboapv encoder user guide for a list of accepted parame-
ters.

libsvtav1
SVT-AV1 encoder wrapper.

Requires the presence of the SVT-AV1 headers and library during configura-
tion. You need to explicitly configure the build with "--enable-libsv-
tav1".

Options

profile
Set the encoding profile.

main
high
professional

level
Set the operating point level. For example: '4.0'

hielevel
Set the Hierarchical prediction levels.

3level
4level
This is the default.

tierSet the operating point tier.

mainThis is the default.

high

qmaxSet the maximum quantizer to use when using a bitrate mode.

qminSet the minimum quantizer to use when using a bitrate mode.

crf Constant rate factor value used in crf rate control mode (0-63).

qp Set the quantizer used in cqp rate control mode (0-63).

sc_detection
Enable scene change detection.

la_depth
Set number of frames to look ahead (0-120).

preset
Set the quality-speed tradeoff, in the range 0 to 13. Higher values
are faster but lower quality.

tile_rows
Set log2 of the number of rows of tiles to use (0-6).

tile_columns
Set log2 of the number of columns of tiles to use (0-4).

svtav1-params
Set SVT-AV1 options using a list of key=value pairs separated by ":".
See the SVT-AV1 encoder user guide for a list of accepted parameters.

libsvtjpegxs
SVT-JPEG-XS encoder wrapper.

Requires the presence of the SVT-JPEG-XS headers and library during config-
uration. You need to explicitly configure the build with "--enable-lib-
svtjpegxs".

Options

decomp_v
Set vertical decomposition level

decomp_h
Set horizontal decomposition level

quantization
Set the quantization algorithm.

deadzone
uniform

coding-signs
Enable Signs handling strategy

disable
fast
full

coding-sigf
Enable Significance coding

coding-vpred
Enable Vertical Prediction coding

disable
no_residuals
no_coeffs

libjxl
libjxl JPEG XL encoder wrapper.

Requires the presence of the libjxl headers and library during configura-
tion. You need to explicitly configure the build with "--enable-libjxl".

Options

The libjxl wrapper supports the following options:

distance
Set the target Butteraugli distance. This is a quality setting: lower
distance yields higher quality, with distance=1.0 roughly comparable to
libjpeg Quality 90 for photographic content. Setting distance=0.0
yields true lossless encoding. Valid values range between 0.0 and 15.0,
and sane values rarely exceed 5.0. Setting distance=0.1 usually attains
transparency for most input. The default is 1.0.

effort
Set the encoding effort used. Higher effort values produce more consis-
tent quality and usually produces a better quality/bpp curve, at the
cost of more CPU time required. Valid values range from 1 to 9, and the
default is 7.

modular
Force the encoder to use Modular mode instead of choosing automati-
cally. The default is to use VarDCT for lossy encoding and Modular for
lossless. VarDCT is generally superior to Modular for lossy encoding
but does not support lossless encoding.

libkvazaar
Kvazaar H.265/HEVC encoder.

Requires the presence of the libkvazaar headers and library during configu-
ration. You need to explicitly configure the build with --en-
able-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 com-
mas (,). 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 li-
bopenh264 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.

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 configu-
ration. You need to explicitly configure the build with "--enable-libthe-
ora".

For more information about the libtheora project see <http://www.the-
ora.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 li-
brary 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 configura-
tion. You need to explicitly configure the build with "--enable-libvpx".

Options

The following options are supported by the libvpx wrapper. The vpx-
enc-equivalent options or values are listed in parentheses for easy migra-
tion.

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

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)
Minimum (Best Quality) Quantizer.

qmax (max-q)
Maximum (Worst Quality) Quantizer. Can be changed per-frame.

bufsize (buf-sz, buf-optimal-sz)
Set ratecontrol buffer size (in bits). Note vpxenc's options are speci-
fied in milliseconds, the libvpx wrapper converts this value as fol-
lows: "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 de-
coding 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)
bestUse best quality deadline. Poorly named and quite slow, this option
should be avoided as it may give worse quality output than good.

goodUse 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). Values
greater than 1 enable multi-layer alternate reference frames (VP9
only).

arnr-maxframes
Set altref noise reduction max frame count.

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

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.

min-gf-interval
Set minimum golden/alternate reference frame interval (VP9 only).

error-resilient
Enable error resiliency features.

sharpness integer
Increase sharpness at the expense of lower PSNR. The valid range is
[0, 7].

ts-parameters
Sets the temporal scalability configuration using a :-separated list of
key=value pairs. For example, to specify temporal scalability parame-
ters with "ffmpeg":

ffmpeg -i INPUT -c:v libvpx -ts-parameters ts_number_layers=3:\
ts_target_bitrate=250,500,1000:ts_rate_decimator=4,2,1:\
ts_periodicity=4:ts_layer_id=0,2,1,2:ts_layering_mode=3 OUTPUT

Below is a brief explanation of each of the parameters, please refer to
"struct vpx_codec_enc_cfg" in "vpx/vpx_encoder.h" for more details.

ts_number_layers
Number of temporal coding layers.

ts_target_bitrate
Target bitrate for each temporal layer (in kbps). (bitrate should
be inclusive of the lower temporal layer).

ts_rate_decimator
Frame rate decimation factor for each temporal layer.

ts_periodicity
Length of the sequence defining frame temporal layer membership.

ts_layer_id
Template defining the membership of frames to temporal layers.

ts_layering_mode
(optional) Selecting the temporal structure from a set of pre-de-
fined temporal layering modes. Currently supports the following
options.

0 No temporal layering flags are provided internally, relies on
flags being passed in using "metadata" field in "AVFrame" with
following keys.

vp8-flags
Sets the flags passed into the encoder to indicate the ref-
erencing scheme for the current frame. Refer to function
"vpx_codec_encode" in "vpx/vpx_encoder.h" for more details.

temporal_id
Explicitly sets the temporal id of the current frame to en-
code.

2 Two temporal layers. 0-1...

3 Three temporal layers. 0-2-1-2...; with single reference frame.

4 Same as option "3", except there is a dependency between the
two temporal layer 2 frames within the temporal period.

VP8-specific options
screen-content-mode
Screen content mode, one of: 0 (off), 1 (screen), 2 (screen with
more aggressive rate control).

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.

enable-tpl boolean
Enable temporal dependency model.

ref-frame-config
Using per-frame metadata, set members of the structure
"vpx_svc_ref_frame_config_t" in "vpx/vp8cx.h" to fine-control ref-
erencing schemes and frame buffer management. Use a :-separated
list of key=value pairs. For example,

av_dict_set(&av_frame->metadata, "ref-frame-config", \
"rfc_update_buffer_slot=7:rfc_lst_fb_idx=0:rfc_gld_fb_idx=1:rfc_alt_fb_idx=2:rfc_reference_last=0:rfc_reference_golden=0:rfc_reference_alt_ref=0");

rfc_update_buffer_slot
Indicates the buffer slot number to update

rfc_update_last
Indicates whether to update the LAST frame

rfc_update_golden
Indicates whether to update GOLDEN frame

rfc_update_alt_ref
Indicates whether to update ALT_REF frame

rfc_lst_fb_idx
LAST frame buffer index

rfc_gld_fb_idx
GOLDEN frame buffer index

rfc_alt_fb_idx
ALT_REF frame buffer index

rfc_reference_last
Indicates whether to reference LAST frame

rfc_reference_golden
Indicates whether to reference GOLDEN frame

rfc_reference_alt_ref
Indicates whether to reference ALT_REF frame

rfc_reference_duration
Indicates frame duration

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

libvvenc
VVenC H.266/VVC encoder wrapper.

This encoder requires the presence of the libvvenc headers and library dur-
ing configuration. You need to explicitly configure the build with --en-
able-libvvenc.

The VVenC project website is at <https://github.com/fraunhoferhhi/vvenc>.

Supported Pixel Formats

VVenC supports only 10-bit color spaces as input. But the internal (en-
coded) bit depth can be set to 8-bit or 10-bit at runtime.

Options

b Sets target video bitrate.

g Set the GOP size. Currently support for g=1 (Intra only) or default.

preset
Set the VVenC preset.

levelidc
Set level idc.

tierSet vvc tier.

qp Set constant quantization parameter.

subopt boolean
Set subjective (perceptually motivated) optimization. Default is 1
(on).

bitdepth8 boolean
Set 8bit coding mode instead of using 10bit. Default is 0 (off).

period
set (intra) refresh period in seconds.

vvenc-params
Set vvenc options using a list of key=value couples separated by ":".
See vvencapp --fullhelp or vvencFFapp --fullhelp for a list of options.

For example, the options might be provided as:

intraperiod=64:decodingrefreshtype=idr:poc0idr=1:internalbitdepth=8

For example the encoding options might be provided with -vvenc-params:

ffmpeg -i input -c:v libvvenc -b 1M -vvenc-params intraperiod=64:decodingrefreshtype=idr:poc0idr=1:internalbitdepth=8 output.mp4

libwebp
libwebp WebP Image encoder wrapper

libwebp is Google's official encoder for WebP images. It can encode in ei-
ther 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 automati-
cally 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 con-
trols 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.

-quality float
For lossy encoding, this controls image quality. For lossless encoding,
this controls the effort and time spent in compression. Range is 0 to
100. Default is 75.

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

noneDo 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

iconSmall-sized colorful images

textText-like

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

This encoder requires the presence of the libx264 headers and library dur-
ing configuration. You need to explicitly configure the build with "--en-
able-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. Addi-
tionally 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/develop-
ers/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.

Options

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

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

In the list below, note that the x264 option name is shown in parentheses
after the libavcodec corresponding name, in case there is a direct mapping.

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)
Number of B-frames between I and P-frames

g (keyint)
Maximum GOP size

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 0-16.

level (level)
Set the "x264_param_t.i_level_idc" value in case the value is positive,
it is ignored otherwise.

This value can be set using the "AVCodecContext" API (e.g. by setting
the "AVCodecContext" value directly), and is specified as an integer
mapped on a corresponding level (e.g. the value 31 maps to H.264 level
IDC "3.1", as defined in the "x264_levels" table). It is ignored when
set to a non positive value.

Alternatively it can be set as a private option, overriding the value
set in "AVCodecContext", and in this case must be specified as the
level IDC identifier (e.g. "3.1"), as defined by H.264 Annex A.

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

trellis (trellis)
Performs Trellis quantization to increase efficiency. Enabled by de-
fault.

nr (nr)
Noise reduction

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 behav-
ior of x264's --open-gop option.

rc_init_occupancy (vbv-init)
Initial VBV buffer occupancy

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 ar-
eas.

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 for-
mat.

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 refer-
ence per macroblock when set to 1. When set to 0, it has the same ef-
fect 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 op-
tion.

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 values. Possi-
ble values in the list:

p8x88x8 P-frame partition.

p4x44x4 P-frame partition.

b8x84x4 B-frame partition.

i8x88x8 I-frame partition.

i4x44x4 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 opts
x264-params opts
Override the x264 configuration using a :-separated list of key=value
options.

The argument for both options is a list of key=value couples separated
by ":". With x264opts the value can be omitted, and the value 1 is as-
sumed in that case.

For filter and psy-rd options values that use ":" as a separator them-
selves, use "," instead. They accept it as well since long ago but this
is kept undocumented for some reason.

For example, the options might be provided as:

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

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

To get the complete list of the libx264 options, invoke the command
x264 --fullhelp or consult the libx264 documentation.

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

udu_sei boolean
Import user data unregistered SEI if available into output. Default is
0 (off).

mb_info boolean
Set mb_info data through AVFrameSideData, only useful when used from
the API. Default is 0 (off).

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 dur-
ing configuration. You need to explicitly configure the build with --en-
able-libx265.

Options

b Sets target video bitrate.

bf
g Set the GOP size.

keyint_min
Minimum GOP size.

refsNumber of reference frames each P-frame can use. The range is from
1-16.

preset
Set the x265 preset.

tuneSet the x265 tune parameter.

profile
Set profile restrictions.

crf Set the quality for constant quality mode.

qp Set constant quantization rate control method parameter.

qminMinimum quantizer scale.

qmaxMaximum quantizer scale.

qdiff
Maximum difference between quantizer scales.

qblur
Quantizer curve blur

qcomp
Quantizer curve compression factor

i_qfactor
b_qfactor
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-stats
Specify the file name for 2-pass stats. This is set automatically when
using the -passlogfile option.

udu_sei boolean
Import user data unregistered SEI if available into output. Default is
0 (off).

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

libxavs2
xavs2 AVS2-P2/IEEE1857.4 encoder wrapper.

This encoder requires the presence of the libxavs2 headers and library dur-
ing configuration. You need to explicitly configure the build with --en-
able-libxavs2.

The following standard libavcodec options are used:

* b / bit_rate

* g / gop_size

* bf / max_b_frames

The encoder also has its own specific options:

Options

lcu_row_threads
Set the number of parallel threads for rows from 1 to 8 (default 5).

initial_qp
Set the xavs2 quantization parameter from 1 to 63 (default 34). This is
used to set the initial qp for the first frame.

qp Set the xavs2 quantization parameter from 1 to 63 (default 34). This is
used to set the qp value under constant-QP mode.

max_qp
Set the max qp for rate control from 1 to 63 (default 55).

min_qp
Set the min qp for rate control from 1 to 63 (default 20).

speed_level
Set the Speed level from 0 to 9 (default 0). Higher is better but
slower.

log_level
Set the log level from -1 to 3 (default 0). -1: none, 0: error, 1:
warning, 2: info, 3: debug.

xavs2-params
Set xavs2 options using a list of key=value couples separated by ":".

For example to specify libxavs2 encoding options with -xavs2-params:

ffmpeg -i input -c:v libxavs2 -xavs2-params RdoqLevel=0 output.avs2

libxeve
eXtra-fast Essential Video Encoder (XEVE) MPEG-5 EVC encoder wrapper. The
xeve-equivalent options or values are listed in parentheses for easy migra-
tion.

This encoder requires the presence of the libxeve headers and library dur-
ing configuration. You need to explicitly configure the build with --en-
able-libxeve.

Many libxeve encoder options are mapped to FFmpeg global codec options,
while unique encoder options are provided through private options. Ad-
ditionally the xeve-params private options allows one to pass a list of
key=value tuples as accepted by the libxeve "parse_xeve_params" func-
tion.

The xeve project website is at <https://github.com/mpeg5/xeve>.

Options

The following options are supported by the libxeve wrapper. The
xeve-equivalent options or values are listed in parentheses for easy migra-
tion.

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 libxeve op-
tions, invoke the command "xeve_app --help" or consult the libxeve
documentation.

b (bitrate)
Set target video bitrate in bits/s. Note that FFmpeg's b option is ex-
pressed in bits/s, while xeve's bitrate is in kilobits/s.

bf (bframes)
Set the maximum number of B frames (1,3,7,15).

g (keyint)
Set the GOP size (I-picture period).

preset (preset)
Set the xeve preset. Set the encoder preset value to determine encod-
ing speed [fast, medium, slow, placebo]

tune (tune)
Set the encoder tune parameter [psnr, zerolatency]

profile (profile)
Set the encoder profile [0: baseline; 1: main]

crf (crf)
Set the quality for constant quality mode. Constant rate factor
<10..49> [default: 32]

qp (qp)
Set constant quantization rate control method parameter. Quantization
parameter qp <0..51> [default: 32]

threads (threads)
Force to use a specific number of threads

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 documenta-
tion. 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.

grayOnly encode grayscale.

qpelEnable quarter-pixel motion compensation.

cgopEnable closed GOP.

global_header
Place global headers in extradata instead of every keyframe.

gmc Enable the use of global motion compensation (GMC). Default is 0 (dis-
abled).

me_quality
Set motion estimation quality level. Possible values in decreasing or-
der of speed and increasing order of quality:

0 Use no motion estimation (default).

1, 2Enable advanced diamond zonal search for 16x16 blocks and
half-pixel refinement for 16x16 blocks.

3, 4Enable all of the things described above, plus advanced diamond
zonal search for 8x8 blocks and half-pixel refinement for 8x8
blocks, also enable motion estimation on chroma planes for P and
B-frames.

5, 6Enable 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).

bitsEnable rate distortion-based half pixel and quarter pixel refine-
ment for 16x16 blocks.

rd Enable all of the things described above, plus rate distor-
tion-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 (dis-
abled).

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

trellis
Set rate-distortion optimal quantization.

ssimSet 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.

MediaCodec
MediaCodec encoder wrapper enables hardware-accelerated video encoding on
Android device. It supports H.264, H.265 (HEVC), VP8, VP9, MPEG-4, and AV1
encoding (whether works or not is device dependent).

Android provides two sets of APIs: Java MediaCodec and NDK MediaCodec. The
MediaCodec encoder wrapper supports both. Note that the NDK MediaCodec API
operates without requiring JVM, but may fail to function outside the JVM
environment due to dependencies on system framework services, particularly
after Android 15.

ndk_codec boolean
Use the NDK-based MediaCodec API instead of the Java API. Enabled by
default if av_jni_get_java_vm() return NULL.

ndk_async boolean
Use NDK MediaCodec in async mode. Async mode has less overhead than
poll in a loop in sync mode. The drawback of async mode is
AV_CODEC_FLAG_GLOBAL_HEADER doesn't work (use extract_extradata bsf
when necessary). It doesn't work and will be disabled automatically on
devices below Android 8.0.

codec_name string
A codec type can have multiple implementations on a single device, this
option specify which backend to use (via MediaCodec createCodecByName
API). It's NULL by default, and encoder is created by createEncoderBy-
Type.

bitrate_mode integer
Possible values:

cq Constant quality mode

vbr Variable bitrate mode

cbr Constant bitrate mode

cbr_fd
Constant bitrate mode with frame drops

pts_as_dts boolean
Use PTS as DTS. This is a workaround since MediaCodec API doesn't pro-
vide decoding timestamp. It is enabled automatically if B frame is 0.

operating_rate integer
The desired operating rate that the codec will need to operate at, zero
for unspecified. This is used for cases like high-speed/slow-motion
video capture, where the video encoder format contains the target play-
back rate (e.g. 30fps), but the component must be able to handle the
high operating capture rate (e.g. 240fps). This rate will be used by
codec for resource planning and setting the operating points.

qp_i_min integer
Minimum quantization parameter for I frame.

qp_p_min integer
Minimum quantization parameter for P frame.

qp_b_min integer
Minimum quantization parameter for B frame.

qp_i_max integer
Maximum quantization parameter for I frame.

qp_p_max integer
Maximum quantization parameter for P frame.

qp_b_max integer
Maximum quantization parameter for B frame.

MediaFoundation
The following wrappers for encoders in the MediaFoundation framework are
available:

*<h264_mf>
*<hevc_mf>
*<av1_mf>

These support both software and hardware encoding.

Video encoders can take input in either of nv12 or yuv420p form (some en-
coders support both, some support only either - in practice, nv12 is the
safer choice, especially among HW encoders).

Hardware-accelerated encoding requires D3D11, including hardware scaling
capabilities through the scale_d3d11 filter.

To list all available options for the MediaFoundation encoders, use: ffmpeg
-h encoder=<encoder> e.g. ffmpeg -h encoder=h264_mf

Options

rate_control
Select rate control mode. Available modes:

default
Default mode

cbr CBR mode

pc_vbr
Peak constrained VBR mode

u_vbr
Unconstrained VBR mode

quality
Quality mode

ld_vbr
Low delay VBR mode (requires Windows 8+)

g_vbr
Global VBR mode (requires Windows 8+)

gld_vbr
Global low delay VBR mode (requires Windows 8+)

scenario
Select usage scenario. Available scenarios:

default
Default scenario

display_remoting
Display remoting scenario

video_conference
Video conference scenario

archive
Archive scenario

live_streaming
Live streaming scenario

camera_record
Camera record scenario

display_remoting_with_feature_map
Display remoting with feature map scenario

quality
Set encoding quality (0-100). -1 means default quality.

hw_encoding
Force hardware encoding (0-1). Default is 0 (disabled).

Examples

Hardware encoding:

ffmpeg -i input.mp4 -c:v h264_mf -hw_encoding 1 output.mp4

Hardware-accelerated decoding with hardware encoding:

ffmpeg -hwaccel d3d11va -i input.mp4 -c:v h264_mf -hw_encoding 1 output.mp4

Hardware-accelerated decoding, HW scaling and encoding with quality set-
ting:

ffmpeg -hwaccel d3d11va -hwaccel_output_format d3d11 -i input.mp4 -vf scale_d3d11=1920:1080 -c:v hevc_mf -hw_encoding 1 -quality 80 output.mp4

Microsoft RLE
Microsoft RLE aka MSRLE encoder. Only 8-bit palette mode supported. Com-
patible with Windows 3.1 and Windows 95.

Options

g integer
Keyframe interval. A keyframe is inserted at least every "-g" frames,
sometimes sooner.

mpeg2
MPEG-2 video encoder.

Options

profile
Select the mpeg2 profile to encode:

422
high
ss Spatially Scalable

snr SNR Scalable

main
simple

level
Select the mpeg2 level to encode:

high
high1440
main
low

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

-1
autoDecide 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 unspeci-
fied, can be component, pal, ntsc, secam or mac. For maximum compati-
bility, use component.

a53cc boolean
Import closed captions (which must be ATSC compatible format) into out-
put. Default is 1 (on).

png
PNG image encoder.

Options

compression_level
Sets the compression level, from 0 to 9(default)

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

pred method
Set prediction method (none, sub, up, avg, paeth, mixed), default is
paeth

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 mak-
ing 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 search-
ing 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 recom-
mended value) and do not set a size constraint.

QSV Encoders
The family of Intel QuickSync Video encoders (MPEG-2, H.264, HEVC,
JPEG/MJPEG, VP9, AV1)

Ratecontrol Method

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. For the ICQ modes,
global quality range is 1 to 51, with 1 being the best quality.

* Otherwise when the desired average bitrate is specified with the b op-
tion, a bitrate-based mode is used.

- 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, both
avbr_accuracy and avbr_convergence are set to non-zero. This mode
is available for H264 and HEVC on Windows.

* Otherwise the default ratecontrol method CQP is used.

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

Global Options -> MSDK Options

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.

Common Options

Following options are used by all qsv encoders.

async_depth
Specifies how many asynchronous operations an application performs be-
fore the application explicitly synchronizes the result. If zero, the
value is not specified.

preset
This option itemizes a range of choices from veryfast (best speed) to
veryslow (best quality).

veryfast
faster
fast
medium
slow
slower
veryslow

forced_idr
Forcing I frames as IDR frames.

low_power
For encoders set this flag to ON to reduce power consumption and GPU
usage.

Runtime Options

Following options can be used during qsv encoding.

global_quality
i_quant_factor
i_quant_offset
b_quant_factor
b_quant_offset
Supported in h264_qsv and hevc_qsv. Change these value to reset qsv
codec's qp configuration.

max_frame_size
Supported in h264_qsv and hevc_qsv. Change this value to reset qsv
codec's MaxFrameSize configuration.

gop_size
Change this value to reset qsv codec's gop configuration.

int_ref_type
int_ref_cycle_size
int_ref_qp_delta
int_ref_cycle_dist
Supported in h264_qsv and hevc_qsv. Change these value to reset qsv
codec's Intra Refresh configuration.

qmax
qmin
max_qp_i
min_qp_i
max_qp_p
min_qp_p
max_qp_b
min_qp_b
Supported in h264_qsv. Change these value to reset qsv codec's max/min
qp configuration.

low_delay_brc
Supported in h264_qsv, hevc_qsv and av1_qsv. Change this value to re-
set qsv codec's low_delay_brc configuration.

framerate
Change this value to reset qsv codec's framerate configuration.

bit_rate
rc_buffer_size
rc_initial_buffer_occupancy
rc_max_rate
Change these value to reset qsv codec's bitrate control configuration.

pic_timing_sei
Supported in h264_qsv and hevc_qsv. Change this value to reset qsv
codec's pic_timing_sei configuration.

qsv_params
Set QSV encoder parameters as a colon-separated list of key-value
pairs.

The qsv_params should be formatted as "key1=value1:key2=value2:...".

These parameters are passed directly to the underlying Intel Quick Sync
Video (QSV) encoder using the MFXSetParameter function.

Example:

ffmpeg -i input.mp4 -c:v h264_qsv -qsv_params "CodingOption1=1:CodingOption2=2" output.mp4

This option allows fine-grained control over various encoder-specific
settings provided by the QSV encoder.

H264 options

These options are used by h264_qsv

extbrc
Extended bitrate control.

recovery_point_sei
Set this flag to insert the recovery point SEI message at the beginning
of every intra refresh cycle.

rdo Enable rate distortion optimization.

max_frame_size
Maximum encoded frame size in bytes.

max_frame_size_i
Maximum encoded frame size for I frames in bytes. If this value is set
as larger than zero, then for I frames the value set by max_frame_size
is ignored.

max_frame_size_p
Maximum encoded frame size for P frames in bytes. If this value is set
as larger than zero, then for P frames the value set by max_frame_size
is ignored.

max_slice_size
Maximum encoded slice size in bytes.

bitrate_limit
Toggle bitrate limitations. Modifies bitrate to be in the range im-
posed by the QSV encoder. Setting this flag off may lead to violation
of HRD conformance. Mind that specifying bitrate below the QSV encoder
range might significantly affect quality. If on this option takes ef-
fect in non CQP modes: if bitrate is not in the range imposed by the
QSV encoder, it will be changed to be in the range.

mbbrc
Setting this flag enables macroblock level bitrate control that gener-
ally improves subjective visual quality. Enabling this flag may have
negative impact on performance and objective visual quality metric.

low_delay_brc
Setting this flag turns on or off LowDelayBRC feature in qsv plugin,
which provides more accurate bitrate control to minimize the variance
of bitstream size frame by frame. Value: -1-default 0-off 1-on

adaptive_i
This flag controls insertion of I frames by the QSV encoder. Turn ON
this flag to allow changing of frame type from P and B to I.

adaptive_b
This flag controls changing of frame type from B to P.

p_strategy
Enable P-pyramid: 0-default 1-simple 2-pyramid(bf need to be set to 0).

b_strategy
This option controls usage of B frames as reference.

dblk_idc
This option disable deblocking. It has value in range 0~2.

cavlc
If set, CAVLC is used; if unset, CABAC is used for encoding.

vcm Video conferencing mode, please see ratecontrol method.

idr_interval
Distance (in I-frames) between IDR frames.

pic_timing_sei
Insert picture timing SEI with pic_struct_syntax element.

single_sei_nal_unit
Put all the SEI messages into one NALU.

max_dec_frame_buffering
Maximum number of frames buffered in the DPB.

look_ahead
Use VBR algorithm with look ahead.

look_ahead_depth
Depth of look ahead in number frames.

look_ahead_downsampling
Downscaling factor for the frames saved for the lookahead analysis.

unknown
auto
off
2x
4x

int_ref_type
Specifies intra refresh type. The major goal of intra refresh is im-
provement of error resilience without significant impact on encoded
bitstream size caused by I frames. The SDK encoder achieves this by en-
coding part of each frame in refresh cycle using intra MBs. none means
no refresh. vertical means vertical refresh, by column of MBs. horizon-
tal means horizontal refresh, by rows of MBs. slice means horizontal
refresh by slices without overlapping. In case of slice, in_ref_cy-
cle_size is ignored. To enable intra refresh, B frame should be set to
0.

int_ref_cycle_size
Specifies number of pictures within refresh cycle starting from 2. 0
and 1 are invalid values.

int_ref_qp_delta
Specifies QP difference for inserted intra MBs. This is signed value in
[-51, 51] range if target encoding bit-depth for luma samples is 8 and
this range is [-63, 63] for 10 bit-depth or [-75, 75] for 12 bit-depth
respectively.

int_ref_cycle_dist
Distance between the beginnings of the intra-refresh cycles in frames.

profile
unknown
baseline
main
high

a53cc
Use A53 Closed Captions (if available).

aud Insert the Access Unit Delimiter NAL.

mfmode
Multi-Frame Mode.

off
auto

repeat_pps
Repeat pps for every frame.

max_qp_i
Maximum video quantizer scale for I frame.

min_qp_i
Minimum video quantizer scale for I frame.

max_qp_p
Maximum video quantizer scale for P frame.

min_qp_p
Minimum video quantizer scale for P frame.

max_qp_b
Maximum video quantizer scale for B frame.

min_qp_b
Minimum video quantizer scale for B frame.

scenario
Provides a hint to encoder about the scenario for the encoding session.

unknown
displayremoting
videoconference
archive
livestreaming
cameracapture
videosurveillance
gamestreaming
remotegaming

avbr_accuracy
Accuracy of the AVBR ratecontrol (unit of tenth of percent).

avbr_convergence
Convergence of the AVBR ratecontrol (unit of 100 frames)

The parameters avbr_accuracy and avbr_convergence are for the average
variable bitrate control (AVBR) algorithm. The algorithm focuses on
overall encoding quality while meeting the specified bitrate, tar-
get_bitrate, within the accuracy range avbr_accuracy, after a avbr_Con-
vergence period. This method does not follow HRD and the instant bi-
trate is not capped or padded.

skip_frame
Use per-frame metadata "qsv_skip_frame" to skip frame when encoding.
This option defines the usage of this metadata.

no_skip
Frame skipping is disabled.

insert_dummy
Encoder inserts into bitstream frame where all macroblocks are en-
coded as skipped.

insert_nothing
Similar to insert_dummy, but encoder inserts nothing into bit-
stream. The skipped frames are still used in brc. For example, gop
still include skipped frames, and the frames after skipped frames
will be larger in size.

brc_only
skip_frame metadata indicates the number of missed frames before
the current frame.

HEVC Options

These options are used by hevc_qsv

extbrc
Extended bitrate control.

recovery_point_sei
Set this flag to insert the recovery point SEI message at the beginning
of every intra refresh cycle.

rdo Enable rate distortion optimization.

max_frame_size
Maximum encoded frame size in bytes.

max_frame_size_i
Maximum encoded frame size for I frames in bytes. If this value is set
as larger than zero, then for I frames the value set by max_frame_size
is ignored.

max_frame_size_p
Maximum encoded frame size for P frames in bytes. If this value is set
as larger than zero, then for P frames the value set by max_frame_size
is ignored.

max_slice_size
Maximum encoded slice size in bytes.

adaptive_i
This flag controls insertion of I frames by the QSV encoder. Turn ON
this flag to allow changing of frame type from P and B to I.

adaptive_b
This flag controls changing of frame type from B to P.

p_strategy
Enable P-pyramid: 0-default 1-simple 2-pyramid(bf need to be set to 0).

b_strategy
This option controls usage of B frames as reference.

dblk_idc
This option disable deblocking. It has value in range 0~2.

idr_interval
Distance (in I-frames) between IDR frames.

begin_only
Output an IDR-frame only at the beginning of the stream.

load_plugin
A user plugin to load in an internal session.

none
hevc_sw
hevc_hw

load_plugins
A :-separate list of hexadecimal plugin UIDs to load in an internal
session.

look_ahead_depth
Depth of look ahead in number frames, available when extbrc option is
enabled.

profile
Set the encoding profile (scc requires libmfx >= 1.32).

unknown
main
main10
mainsp
rext
scc

tierSet the encoding tier (only level >= 4 can support high tier). This
option only takes effect when the level option is specified.

main
high

gpb 1: GPB (generalized P/B frame)

0: regular P frame.

tile_cols
Number of columns for tiled encoding.

tile_rows
Number of rows for tiled encoding.

aud Insert the Access Unit Delimiter NAL.

pic_timing_sei
Insert picture timing SEI with pic_struct_syntax element.

transform_skip
Turn this option ON to enable transformskip. It is supported on plat-
form equal or newer than ICL.

int_ref_cycle_size
Specifies number of pictures within refresh cycle starting from 2. 0
and 1 are invalid values.

int_ref_cycle_dist
Distance between the beginnings of the intra-refresh cycles in frames.

max_qp_i
Maximum video quantizer scale for I frame.

min_qp_i
Minimum video quantizer scale for I frame.

max_qp_p
Maximum video quantizer scale for P frame.

min_qp_p
Minimum video quantizer scale for P frame.

max_qp_b
Maximum video quantizer scale for B frame.

min_qp_b
Minimum video quantizer scale for B frame.

scenario
Provides a hint to encoder about the scenario for the encoding session.

unknown
displayremoting
videoconference
archive
livestreaming
cameracapture
videosurveillance
gamestreaming
remotegaming

avbr_accuracy
Accuracy of the AVBR ratecontrol (unit of tenth of percent).

avbr_convergence
Convergence of the AVBR ratecontrol (unit of 100 frames)

skip_frame
Use per-frame metadata "qsv_skip_frame" to skip frame when encoding.
This option defines the usage of this metadata.

no_skip
Frame skipping is disabled.

insert_dummy
Encoder inserts into bitstream frame where all macroblocks are en-
coded as skipped.

brc_only
skip_frame metadata indicates the number of missed frames before
the current frame.

MPEG2 Options

These options are used by mpeg2_qsv

profile
unknown
simple
main
high

VP9 Options

These options are used by vp9_qsv

profile
unknown
profile0
profile1
profile2
profile3

tile_cols
Number of columns for tiled encoding (requires libmfx >= 1.29).

tile_rows
Number of rows for tiled encoding (requires libmfx >= 1.29).

AV1 Options

These options are used by av1_qsv (requires libvpl).

profile
unknown
main

tile_cols
Number of columns for tiled encoding.

tile_rows
Number of rows for tiled encoding.

adaptive_i
This flag controls insertion of I frames by the QSV encoder. Turn ON
this flag to allow changing of frame type from P and B to I.

adaptive_b
This flag controls changing of frame type from B to P.

b_strategy
This option controls usage of B frames as reference.

extbrc
Extended bitrate control.

look_ahead_depth
Depth of look ahead in number frames, available when extbrc option is
enabled.

max_frame_size
Set the allowed max size in bytes for each frame. If the frame size ex-
ceeds the limitation, encoder will adjust the QP value to control the
frame size. Invalid in CQP rate control mode.

max_frame_size_i
Maximum encoded frame size for I frames in bytes. If this value is set
as larger than zero, then for I frames the value set by max_frame_size
is ignored.

max_frame_size_p
Maximum encoded frame size for P frames in bytes. If this value is set
as larger than zero, then for P frames the value set by max_frame_size
is ignored.

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

If not set, this will be determined automatically from the format of
the input frames and the profiles supported by the driver.

* 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

* qmax

* i_qfactor / i_quant_factor

* i_qoffset / i_quant_offset

* b_qfactor / b_quant_factor

* b_qoffset / b_quant_offset

* slices

All encoders support the following options:

low_power
Some drivers/platforms offer a second encoder for some codecs intended
to use less power than the default encoder; setting this option will
attempt to use that encoder. Note that it may support a reduced fea-
ture set, so some other options may not be available in this mode.

idr_interval
Set the number of normal intra frames between full-refresh (IDR) frames
in open-GOP mode. The intra frames are still IRAPs, but will not in-
clude global headers and may have non-decodable leading pictures.

b_depth
Set the B-frame reference depth. When set to one (the default), all
B-frames will refer only to P- or I-frames. When set to greater values
multiple layers of B-frames will be present, frames in each layer only
referring to frames in higher layers.

async_depth
Maximum processing parallelism. Increase this to improve single channel
performance. This option doesn't work if driver doesn't implement va-
SyncBuffer function. Please make sure there are enough hw_frames allo-
cated if a large number of async_depth is used.

rc_mode
Set the rate control mode to use. A given driver may only support a
subset of modes.

Possible modes:

autoChoose the mode automatically based on driver support and the other
options. This is the default.

CQP Constant-quality.

CBR Constant-bitrate.

VBR Variable-bitrate.

ICQ Intelligent constant-quality.

QVBRQuality-defined variable-bitrate.

AVBRAverage variable bitrate.

blbrc
Enable block level rate control, which assigns different bitrate block
by block. Invalid for CQP mode.

Each encoder also has its own specific options:

av1_vaapi
profile sets the value of seq_profile. tier sets the value of
seq_tier. level sets the value of seq_level_idx.

tiles
Set the number of tiles to encode the input video with, as columns
x rows. (default is auto, which means use minimal tile column/row
number).

tile_groups
Set tile groups number. All the tiles will be distributed as evenly
as possible to each tile group. (default is 1).

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

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

ac
cabac
Use CABAC.

vlc
cavlc
Use CAVLC.

aud Include access unit delimiters in the stream (not included by de-
fault).

sei Set SEI message types to include. Some combination of the follow-
ing values:

identifier
Include a user_data_unregistered message containing information
about the encoder.

timing
Include picture timing parameters (buffering_period and
pic_timing messages).

recovery_point
Include recovery points where appropriate (recovery_point mes-
sages).

hevc_vaapi
profile and level set the values of general_profile_idc and gen-
eral_level_idc respectively.

aud Include access unit delimiters in the stream (not included by de-
fault).

tierSet general_tier_flag. This may affect the level chosen for the
stream if it is not explicitly specified.

sei Set SEI message types to include. Some combination of the follow-
ing values:

hdr Include HDR metadata if the input frames have it (master-
ing_display_colour_volume and content_light_level messages).

tiles
Set the number of tiles to encode the input video with, as columns
x rows. Larger numbers allow greater parallelism in both encoding
and decoding, but may decrease coding efficiency.

mjpeg_vaapi
Only baseline DCT encoding is supported. The encoder always uses the
standard quantisation and huffman tables - global_quality scales the
standard quantisation table (range 1-100).

For YUV, 4:2:0, 4:2:2 and 4:4:4 subsampling modes are supported. RGB
is also supported, and will create an RGB JPEG.

jfifInclude JFIF header in each frame (not included by default).

huffman
Include standard huffman tables (on by default). Turning this off
will save a few hundred bytes in each output frame, but may lose
compatibility with some JPEG decoders which don't fully handle
MJPEG.

mpeg2_vaapi
profile and level set the value of profile_and_level_indication.

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 neces-
sary 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.

vbn
Vizrt Binary Image encoder.

This format is used by the broadcast vendor Vizrt for quick texture stream-
ing. Advanced features of the format such as LZW compression of texture
data or generation of mipmaps are not supported.

Options

format string
Sets the texture compression used by the VBN file. Can be dxt1, dxt5 or
raw. Default is dxt5.

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 uncom-
pressed 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 inter-
laced 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 (Deslauri-
ers-Dubuc) are implemented, with 9_7 being the one with better compres-
sion and thus is the default.

slice_width
slice_height
Sets the slice size for each slice. Larger values result in better com-
pression. 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 specifica-
tions, 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 in-
creases PSNR but might reduce perception. Use in bogus benchmarks.

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

SUBTITLES ENCODERS
dvbsub
This codec encodes the bitmap subtitle format that is used in DVB broad-
casts and recordings. The bitmaps are typically embedded in a container
such as MPEG-TS as a separate stream.

Options

min_bpp integer (2, 4, or 8)
Set a minimum bits-per-pixel value for the subtitle color lookup ta-
bles.

DVB supports 2, 4, and 8 bits-per-pixel color lookup tables. This op-
tion enables forcing a particular bits-per-pixel value regardless of
the number of colors. Since not all players support or properly sup-
port 2 bits-per-pixel, this value defaults to 4.

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

Options

palette
Specify the global palette used by the bitmaps.

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.

lrc
This codec encodes the LRC lyrics format.

Options

precision
Specify the precision of the fractional part of the timestamp. Time
base is determined based on this value.

Defaults to 2 for centiseconds.

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
(https://git.ffmpeg.org/ffmpeg), e.g. by typing the command git log in the
FFmpeg source directory, or browsing the online repository at
<https://git.ffmpeg.org/ffmpeg>.

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

FFMPEG-CODECS(1)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=ffmpeg-codecs&sektion=1&manpath=FreeBSD+Ports+15.1.quarterly>

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