Choppy 4K YouTube playback
I have a very good PC (5800X3D, 7900XT, 32GB DDR4 3600), but Firefox (either the normal, canary and nightly version) can't play smoothly any 4K video (like the Borderlands trailer: https://www.youtube.com/watch?v=lU_NKNZljoQ ). 1440 and lower resolutions are fine, as are 4K videos on Chrome and Edge. FWIW, my CPU during 4K playback is barely used (1-2%), and my GPU's video codec (VCE) is used by around a third. Disabling HW accel makes things better, as it still stutters but it's (barely) passable. I already tried creating a new profile, but still it's the same.
Chosen solution
Install "VP9 Video Extensions" and "AV1 Video Extension" from the Microsoft Store then reboot.
Try disabling the AV1 codec by changing media.av1.enabled to false in about:config.
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Chosen Solution
Install "VP9 Video Extensions" and "AV1 Video Extension" from the Microsoft Store then reboot.
Try disabling the AV1 codec by changing media.av1.enabled to false in about:config.
zeroknight said
Install "VP9 Video Extensions" and "AV1 Video Extension" from the Microsoft Store then reboot. Try disabling the AV1 codec by changing media.av1.enabled to false in about:config.
Thanks! I already had both the extensions installed. Disabling AV1 fixed the problem (despite having a GPU that can decode AV1...). 4K videos are now as smooth as 1440 and lower res.
For AV1 support details, go to about:support in the address bar and check the "Codec Support Information" table.
zeroknight said
For AV1 support details, go to about:support in the address bar and check the "Codec Support Information" table.
Here's my codec support table. Sorry for its language, I'm Italian.