Ubuntu Manpage: gif2webp - Convert a GIF image to WebP

NAME

       gif2webp - Convert a GIF image to WebP

SYNOPSIS

       gif2webp [options] input_file.gif -o output_file.webp

DESCRIPTION

       This manual page documents the gif2webp command.

       gif2webp converts a GIF image to a WebP image.

OPTIONS

The basic options are:

-o string
Specify the name of the output WebP file. If omitted, gif2webp will perform conversion but only
report statistics. Using "-" as output name will direct output to 'stdout'.

-- string
Explicitly specify the input file. This option is useful if the input file starts with an '-' for
instance. This option must appear last. Any other options afterward will be ignored. If the input
file is "-", the data will be read from stdin instead of a file.

-h, -help
Usage information.

-version
Print the version number (as major.minor.revision) and exit.

-lossy Encode the image using lossy compression.

-mixed Mixed compression mode: optimize compression of the image by picking either lossy or lossless
compression for each frame heuristically.

-q float
Specify the compression factor for RGB channels between 0 and 100. The default is 75.
In case of lossless compression (default), a small factor enables faster compression speed, but
produces a larger file. Maximum compression is achieved by using a value of 100.
In case of lossy compression (specified by the -lossy option), a small factor produces a smaller
file with lower quality. Best quality is achieved by using a value of 100.

-m int Specify the compression method to use. This parameter controls the trade off between encoding
speed and the compressed file size and quality. Possible values range from 0 to 6. Default value
is 4. When higher values are used, the encoder will spend more time inspecting additional
encoding possibilities and decide on the quality gain. Lower value can result is faster
processing time at the expense of larger file size and lower compression quality.

-min_size
Encode image to achieve smallest size. This disables key frame insertion and picks the dispose
method resulting in the smallest output for each frame. It uses lossless compression by default,
but can be combined with -q, -m, -lossy or -mixed options.

-kmin int

-kmax int
Specify the minimum and maximum distance between consecutive key frames (independently decodable
frames) in the output animation. The tool will insert some key frames into the output animation as
needed so that this criteria is satisfied.
A 'kmax' value of 0 will turn off insertion of key frames. A 'kmax' value of 1 will result in all
frames being key frames. 'kmin' value is not taken into account in both these special cases.
Typical values are in the range 3 to 30. Default values are kmin = 9, kmax = 17 for lossless
compression and kmin = 3, kmax = 5 for lossy compression.
These two options are relevant only for animated images with large number of frames (>50).
When lower values are used, more frames will be converted to key frames. This may lead to smaller
number of frames required to decode a frame on average, thereby improving the decoding
performance. But this may lead to slightly bigger file sizes. Higher values may lead to worse
decoding performance, but smaller file sizes.
Some restrictions:
(i) kmin < kmax,
(ii) kmin >= kmax / 2 + 1 and
(iii) kmax - kmin <= 30.
If any of these restrictions are not met, they will be enforced automatically.

-metadata string
A comma separated list of metadata to copy from the input to the output if present. Valid values:
all, none, icc, xmp. The default is xmp.

-f int For lossy encoding only (specified by the -lossy option). Specify the strength of the deblocking
filter, between 0 (no filtering) and 100 (maximum filtering). A value of 0 will turn off any
filtering. Higher value will increase the strength of the filtering process applied after decoding
the picture. The higher the value the smoother the picture will appear. Typical values are usually
in the range of 20 to 50.

-mt Use multi-threading for encoding, if possible.

-loop_compatibility
If enabled, handle the loop information in a compatible fashion for Chrome version prior to M62
(inclusive) and Firefox.

-v Print extra information.

-quiet Do not print anything.

BUGS

       Please report all bugs to the issue tracker: https://bugs.chromium.org/p/webp
       Patches         welcome!         See         this         page          to          get          started:
       https://www.webmproject.org/code/contribute/submitting-patches/

EXAMPLES

       gif2webp picture.gif -o picture.webp
       gif2webp -q 70 picture.gif -o picture.webp
       gif2webp -lossy -m 3 picture.gif -o picture_lossy.webp
       gif2webp -lossy -f 50 picture.gif -o picture.webp
       gif2webp -q 70 -o picture.webp -- ---picture.gif
       cat picture.gif | gif2webp -o - -- - > output.webp

AUTHORS

       gif2webp is a part of libwebp and was written by the WebP team.
       The latest source tree is available at https://chromium.googlesource.com/webm/libwebp

       This manual page was written by Urvang Joshi <urvang@google.com>, for the Debian project (and may be used
       by others).