Firefox Beta 136 enables hardware accelerated video decode for AMD on Linux
Firefox Beta 136 enables hardware accelerated video decode for AMD on Linux

Firefox Beta 136.0beta, See All New Features, Updates and Fixes

Firefox Beta 136 enables hardware accelerated video decode for AMD on Linux
Firefox Beta 136.0beta, See All New Features, Updates and Fixes
I could have sworn they did this already a while back.
I still can't play my videos on Firefox without transcoding them, so I honestly hope they get it right this time.
They don't have mkv support by the way, that won't ever work in Firefox. Are you sure you're not trying to play mkv files?