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.TH "AVIFDEC" "1" "2022-04-30" "libavif 1.1.1" "General Commands Manual"
.SH NAME
avifdec - decompress an AVIF file to an image file
.SH SYNOPSIS
\f[B]avifdec\f[R] [\f[I]options\f[R]] \f[I]input.avif\f[R]
\f[I]output.\f[R][\f[I]jpg\f[R]|\f[I]jpeg\f[R]|\f[I]png\f[R]|\f[I]y4m\f[R]]
.PP
\f[B]avifdec\f[R] \f[B]--info\f[R] \f[I]input.avif\f[R]
.SH DESCRIPTION
\f[B]avifdec\f[R] decompresses an AVIF file to an image file.
Output format can be either JPEG, PNG or YUV4MPEG2 (Y4M).
.SH OPTIONS
.TP
\f[B]-h\f[R], \f[B]--help\f[R]
Show syntax help.
.TP
\f[B]-V\f[R], \f[B]--version\f[R]
Show the version number.
.TP
\f[B]-j\f[R], \f[B]--jobs\f[R] \f[I]J\f[R]
Number of jobs (worker threads).
1 or less means single-threaded.
Default is 1.
Use \f[B]all\f[R] to use all available cores.
.TP
\f[B]-c\f[R], \f[B]--codec\f[R] \f[I]C\f[R]
AV1 codec to use.
Possible values depend on the codecs enabled at build time (see
\f[B]--help\f[R] or \f[B]--version\f[R] for the available codecs).
Default is auto-selected from the available codecs.
.RS
.TP
Possible values are:
.IP \[bu] 2
\f[B]aom\f[R]
.IP \[bu] 2
\f[B]dav1d\f[R]
.IP \[bu] 2
\f[B]libgav1\f[R]
.RE
.TP
\f[B]-d\f[R], \f[B]--depth\f[R] \f[I]D\f[R]
Output PNG depth.
Ignored when the output format is JPEG (always 8 bits per channel) or
Y4M (input depth is retained).
.RS
.TP
Possible values are:
.IP \[bu] 2
\f[B]8\f[R]
.IP \[bu] 2
\f[B]16\f[R]
.RE
.TP
\f[B]-q\f[R], \f[B]--quality\f[R] \f[I]Q\f[R]
Output JPEG quality in the range \f[B]0\f[R]-\f[B]100\f[R].
Default is 90.
Ignored if the output format is not JPEG.
.TP
\f[B]--png-compress\f[R] \f[I]L\f[R]
Output PNG compression level in the range \f[B]0\f[R]-\f[B]9\f[R]
(fastest to maximum compression).
Default is libpng\[cq]s built-in default.
Ignored if the output format is not PNG.
.TP
\f[B]-u\f[R], \f[B]--upsampling\f[R] \f[I]U\f[R]
Chroma upsampling method.
Ignored unless the input format is 4:2:0 or 4:2:2.
.RS
.TP
Possible values are:
.IP \[bu] 2
\f[B]automatic\f[R] (default)
.IP \[bu] 2
\f[B]fastest\f[R]
.IP \[bu] 2
\f[B]best\f[R]
.IP \[bu] 2
\f[B]nearest\f[R]
.IP \[bu] 2
\f[B]bilinear\f[R]
.RE
.TP
\f[B]-r\f[R], \f[B]--raw-color\f[R]
Output raw RGB values instead of multiplying by alpha when saving to
opaque formats.
This is available if the output format is JPEG, and not applicable to
y4m.
.TP
\f[B]--index\f[R] \f[I]I\f[R]
When decoding an image sequence or progressive image, specify which
frame index to decode.
Default is 0.
.TP
\f[B]--progressive\f[R]
Enable progressive AVIF processing.
If a progressive image is encountered and \f[B]--progressive\f[R] is
passed, \f[B]avifdec\f[R] will use \f[B]--index\f[R] to choose which
layer to decode (in progressive order).
.TP
\f[B]--no-strict\f[R]
Disable strict decoding, which disables strict validation checks and
errors.
.TP
\f[B]-i\f[R], \f[B]--info\f[R]
Decode all frames and display all image information instead of saving to
disk.
.TP
\f[B]--ignore-icc\f[R]
If the input file contains an embedded ICC profile, ignore it (no-op if
absent).
.TP
\f[B]--size-limit\f[R] \f[I]C\f[R]
Specifies the image size limit (in total pixels) that should be
tolerated.
Default is 268,435,456 pixels (16,384 by 16,384 pixels for a square
image).
.TP
\f[B]--dimension-limit\f[R] \f[I]C\f[R]
Specifies the image dimension limit (width or height) that should be
tolerated.
Default is 32,768.
Set it to 0 to ignore the limit.
.TP
\f[B]--\f[R]
Signals the end of options.
Everything after this is interpreted as file names.
.SH EXAMPLES
.TP
Decompress an AVIF file to a PNG file:
$ \f[B]avifdec input.avif output.png\f[R]
.SH REPORTING BUGS
.TP
Bugs can be reported on GitHub at:
\c
.UR https://github.com/AOMediaCodec/libavif/issues
.UE \c
.SH SEE ALSO
\f[B]avifenc\f[R](1)