Contributed 3rd Party Builds • Re: Pale Moon x86-64 SSE2/AVX2

How does Firefox handle it?

It has media.av1.use-dav1d pref.

No idea but maybe it falls back to safer code if it has the ability to detect the running CPU's capabilities at runtime. Although that would mean to build and provide two different versions of the dav1d decoder. Or simply disable dav1d/AV1 capability altogether if CPU can't handle AVX and the dav1d decoder was built with AVX capability. Or maybe they have another method.

I also see there is a vaapitest executable in its folder for the videocard.

I would've expected for Pale Moon's build script(s) to detect CPU configuration in .mozconfig and automatically enable the --enable-libaom fallback if --enable-av1 was enabled in a SSE2 configuration, but that is not the case. On the other hand the script did throw an error when --enable-libaom was active and --enable-av1 was disabled. Hm. Because of this I'll have to rebuild 34.3.0, and I've not yet decided whether to enable the libaom fallback or just disable AV1 completely - seeing I don't playback videos in the browser anyway.