manpagez: man pages & more
man gif2webp(1)
Home | html | info | man
gif2webp(1)                                                        gif2webp(1)




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 per-
              formance. 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). Spec-
              ify the strength of the deblocking filter, between 0 (no filter-
              ing)  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: http://www.webmpro-
       ject.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.google-
       source.com/webm/libwebp

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



SEE ALSO

       cwebp(1), dwebp(1), webpmux(1)
       Please refer to http://developers.google.com/speed/webp/ for additional
       information.



                                  May 1, 2020                      gif2webp(1)

webp 1.2.0 - Generated Tue Feb 9 18:08:31 CST 2021
© manpagez.com 2000-2021
Individual documents may contain additional copyright information.