[FFmpeg-devel] [PATCH v12 0/8] [WIP] webp: add support for animated WebP decoding

[Thilo Borgmann]

Hi,

[...]
>>> Tests mostly work for me. There are a few images (that I reported
>>> earlier) that give:
>>
>> thanks for testing!
>>
>>
>>>     Canvas change detected. The output will be damaged. Use -threads 1
>>> to try decoding with best effort.
>>> They don't animate without that option and with it render incorrectly.
>>
>> That issue yields from the canvas frame being the synchronization object
>> (ThreadFrame) - doing so prevents the canvas size changed mid-stream.
>> _Maybe_ this can be fixed switching the whole frame multithreading away
>> from ThreadFrame to sth else, not sure though and no experience with the
>> alternatives (AVExecutor?). Maybe Andreas can predict if it's
>> worth/valid to change that whole part of it? I'm not against putting
>> more effort into it to get it right.

I could fix 488x488.webp and have an almost identical output to libwebp.

488x488.webp features an ARGB canvas and has both, ARGB & YUVA420P 
p-frames.

Do you have more files with other variations of canvas & p-frames? If 
they at all exist... e.g. canvas YUV and p-frames RGB?

Pinged Meta as well for real-world samples. Will take some more days 
until I get feedback. Will then post the next iteration...

Thanks,
Thilo