[FFmpeg-devel] [PATCH v4 1/2] libavcodec/webp: add support for animated WebP decoding

[Zlomek, Josef]

On Tue, Sep 8, 2020 at 3:19 PM Moritz Barsnick <barsnick at gmx.net> wrote:

> On Fri, Sep 04, 2020 at 00:59:46 +0200, Lynne wrote:
> Missing version bumps.


There is a version bump for libavformat, as new demuxer was added.
I did not know that version should be increased also when there is a change
in existing decoder in libavcodec. Should it or not?


> And perhaps an explanation why fate changed.
> (Can be here, not in the commit message, if obvious. Was WebP
> previously set to 10 fps by default?)
>

Previously, WebP used generic image demuxer, which uses 25 fps by default.
Usually, web browsers and webp libraries set default fps to 10 if frame
duration is too low.
So the logic in WebP demuxer was implemented similarly - if the frame
duration is not specified (single image) or is too low, the duration is set
to 100 ms resulting in 10 fps.
The fate tests were updated accordingly.

Josef