Oh no. Firefox is using nearest neighbor chroma upsampling. Literally unusable. I'm going back to Chromium.pic.twitter.com/V1Vxu1Dwnq
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I already found the bug, compiling a patched version... Turns out it was the ffmpeg update and Chromium using it badly.
Why not patching Firefox then? 
Because I have no idea where to even begin. The Chrome bug was known, I just had to make a debug build to get a stacktrace and then it was googlable.
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