Uploading animated gif results in corrupted colours

[ghost]

Currently when I upload my avatar, it gets resized and this causes some corruption of the colours:

Original:

Static resized:

This is in v2.9.3.

It would be nice if instead of a poorly compressed gif, animated avatars could be uploaded as either mp4 or webm instead. This would reduce the burden of high speed animations on low end systems and also improve the quality of resized animated avatars.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[Kurty00]

I'm having a similar issue with my avatar. It's corrupting the gif even if I upload it at the size it's supposed to be downscaled to.
Original :

Corrupted :

[TheEssem]

The ImageMagick command used for processing profile picture uploads seems to be missing the -coalesce operator, which is necessary a lot of the time for proper GIF manipulation. However, this also increases the filesize significantly for many GIFs; this can be mitigated slightly with -layers optimize at the end, but it isn't a silver bullet and may just make it worse.

[kescherCode]

In general, when working with GIFs, I've found both ffmpeg and Gifsicle to be much better both in terms of filesize and... not corrupting the GIFs. I might replace GIF optimizations with either of these two in my fork.

[TheEssem]

I can personally vouch for libvips and the cgif encoder, they're incredibly performant and have plenty of options for optimization. Seems like moving away from Paperclip would allow for easier usage of vips, see #7414 and #20269.

[vmstan]

Possible that #30090 addresses this.