Provided by: libavif-bin_1.2.1-1.2ubuntu1_amd64 
NAME
avifenc - compress an image file to an AVIF file
SYNOPSIS
avifenc [options] input.[jpg|jpeg|png|y4m] output.avif
DESCRIPTION
avifenc compresses an image file to an AVIF file. Input format can be either JPEG, PNG or YUV4MPEG2
(Y4M).
OPTIONS
-h, --help
Show syntax help.
-V, --version
Show the version number.
BASIC OPTIONS
-q, --qcolor Q
Quality for color in 0..100 where 100 is lossless.
--qalpha Q
Quality for alpha in 0..100 where 100 is lossless.
-s, --speed S
Encoder speed in 0..10 where 0 is the slowest, 10 is the fastest. Or `default' or `d' for codec
internal defaults. (Default: 6).
ADVANCED OPTIONS
-j, --jobs J
Number of jobs (worker threads), or `all' to potentially use as many cores as possible. (Default:
all).
--no-overwrite
Never overwrite existing output file.
-o, --output FILENAME
Instead of using the last filename given as output, use this filename.
-l, --lossless
Set all defaults to encode losslessly, and emit warnings when settings/input don’t allow for it.
-d, --depth D
Output depth, one of 8, 10 or 12. (JPEG/PNG only; For y4m or stdin, depth is retained).
-y, --yuv FORMAT
Output format, one of `auto' (default), 444, 422, 420 or 400. Ignored for y4m or stdin (y4m
format is retained).
For JPEG, auto honors the JPEG’s internal format, if possible. For grayscale PNG, auto defaults
to 400.
For all other cases, auto defaults to 444.
-p, --premultiply
Premultiply color by the alpha channel and signal this in the AVIF.
--sharpyuv
Use sharp RGB to YUV420 conversion (if supported). Ignored for y4m or if output is not 420.
--stdin
Read y4m frames from stdin instead of files; no input filenames allowed, must set before offering
output filename.
--cicp, --nclx P/T/M
Set CICP values (nclx colr box) (3 raw numbers, use -r to set range flag).
• P = color primaries
• T = transfer characteristics
• M = matrix coefficients
Use 2 for any you wish to leave unspecified.
-r, --range RANGE
YUV range, one of `limited' or `l', `full' or `f'. (JPEG/PNG only, default: full; For y4m or
stdin, range is retained).
--target-size S
Set target file size in bytes (up to 7 times slower)
--progressive
EXPERIMENTAL: Auto set parameters to encode a simple layered image supporting progressive
rendering from a single input frame.
--layered
EXPERIMENTAL: Encode a layered AVIF. Each input is encoded as one layer and at most 4 layers can
be encoded.
-g, --grid MxN
Encode a single-image grid AVIF with M cols & N rows. Either supply MxN identical W/H/D images,
or a single image that can be evenly split into the MxN grid and follow AVIF grid image
restrictions. The grid will adopt the color profile of the first image supplied.
-c, --codec C
Codec to use.
Possible values depend on the codecs enabled at build time (see --help or --version for the
available codecs). Default is auto-selected from the available codecs.
Possible values are:
• aom
• rav1e
• svt
--exif FILENAME
Provide an Exif metadata payload to be associated with the primary item (implies --ignore-exif).
--xmp FILENAME
Provide an XMP metadata payload to be associated with the primary item (implies --ignore-xmp).
--icc FILENAME
Provide an ICC profile payload to be associated with the primary item (implies --ignore-icc).
--timescale, --fps V
Timescale for image sequences. If all frames are 1 timescale in length, this is equivalent to
frames per second. (Default: 30) If neither duration nor timescale are set, avifenc will attempt
to use the framerate stored in a y4m header, if present.
-k, --keyframe INTERVAL
Maximum keyframe interval for image sequences (any set of INTERVAL consecutive frames will have at
least one keyframe). Set to 0 to disable (default).
--ignore-exif
If the input file contains embedded Exif metadata, ignore it (no-op if absent).
--ignore-xmp
If the input file contains embedded XMP metadata, ignore it (no-op if absent).
--ignore-profile, --ignore-icc
If the input file contains an embedded color profile, ignore it (no-op if absent).
--ignore-gain-map
If the input file contains an embedded gain map, ignore it (no-op if absent).
--qgain-map Q
Quality for the gain map in 0..100 where 100 is lossless.
--pasp H,V
Add pasp property (aspect ratio). H=horizontal spacing, V=vertical spacing.
--crop CROPX,CROPY,CROPW,CROPH
Add clap property (clean aperture), but calculated from a crop rectangle.
--clap WN,WD,HN,HD,HON,HOD,VON,VOD
Add clap property (clean aperture). Width, Height, HOffset, VOffset (in numerator/denominator
pairs).
--irot ANGLE
Add irot property (rotation) in 0..3. Makes (90 * ANGLE) degree rotation anti-clockwise.
--imir AXIS
Add imir property (mirroring). 0=top-to-bottom, 1=left-to-right.
--clli MaxCLL,MaxPALL
Add clli property (content light level information).
--repetition-count N
Number of times an animated image sequence will be repeated, or `infinite' for infinite
repetitions. (Default: infinite).
-- Signal the end of options. Everything after this is interpreted as file names.
UPDATABLE OPTIONS
The following options can optionally have a :u (or :update) suffix like -q:u Q, to apply only to input
files appearing after the option:
-q, --qcolor Q
Quality for color in 0..100 where 100 is lossless.
--qalpha Q
Quality for alpha in 0..100 where 100 is lossless.
--qgain-map Q
Quality for the gain map in 0..100 where 100 is lossless.
--tilerowslog2 R
log2 of number of tile rows in 0..6. (Default: 0).
--tilecolslog2 C
log2 of number of tile columns in 0..6. (Default: 0).
--autotiling
Set --tilerowslog2 and --tilecolslog2 automatically.
--scaling-mode N[/D]
EXPERIMENTAL: Set frame (layer) scaling mode as given fraction. If omitted, the denominator
defaults to 1. (Default: 1/1).
--duration D
Frame durations (in timescales) (default: 1). This option always applies to following inputs with
or without the :u suffix.
-a, --advanced KEY[=VALUE]
Pass an advanced, codec-specific key/value string pair directly to the codec. avifenc will warn
on any not used by the codec.
AOM-SPECIFIC ADVANCED OPTIONS
1. <key>=<value> applies to both the color (YUV) planes and the alpha plane (if present).
2. color:<key>=<value> or c:<key>=<value> applies only to the color (YUV) planes.
3. alpha:<key>=<value> or a:<key>=<value> applies only to the alpha plane (if present). Since the alpha
plane is encoded as a monochrome image, the options that refer to the chroma planes, such as
enable-chroma-deltaq=B, should not be used with the alpha plane. In addition, the film grain options
are unlikely to make sense for the alpha plane.
When used with libaom 3.0.0 or later, any key-value pairs supported by the aom_codec_set_option()
function can be used. When used with libaom 2.0.x or older, the following key-value pairs can be used:
aq-mode=M
Adaptive quantization mode. 0=off (default), 1=variance, 2=complexity, 3=cyclic refresh.
cq-level=Q
Constant/Constrained Quality level in 0..63, end-usage must be set to cq or q.
enable-chroma-deltaq=B
Enable delta quantization in chroma planes. 0=disable (default), 1=enable.
end-usage=MODE
Rate control mode, one of `vbr', `cbr', `cq', or `q'
sharpness=S
Bias towards block sharpness in rate-distortion optimization of transform coefficients in 0..7.
(Default: 0).
tune=METRIC
Tune the encoder for distortion metric, one of `psnr' or `ssim'. (Default: psnr).
film-grain-test=TEST
Film grain test vectors in 0..16. 0=none (default), 1=test1, 2=test2, ... 16=test16.
film-grain-table=FILENAME
Path to file containing film grain parameters.
EXAMPLES
Compress a PNG file to an AVIF file:
$ avifenc input.png output.avif
REPORTING BUGS
Bugs can be reported on GitHub at:
https://github.com/AOMediaCodec/libavif/issues
SEE ALSO
avifdec(1)
libavif 1.2.1 2022-04-30 AVIFENC(1)