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

[Moritz Barsnick]

On Wed, Sep 09, 2020 at 09:57:24 +0200, Zlomek, Josef wrote:
> On Tue, Sep 8, 2020 at 3:19 PM Moritz Barsnick <barsnick at gmx.net> wrote:
> > Missing version bumps.
> There is a version bump for libavformat, as new demuxer was added.

I didn't see that in v4.

> I did not know that version should be increased also when there is a change
> in existing decoder in libavcodec. Should it or not?

I guess not. Since you're expanding the feature set, you should at
least bump micro.

> > 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.

Okay, thank you, I understand now. :-)

Moritz