Forum der Gemeinschaft Firefox

Some videos work perfectly fine, however for some videos audio lags behind the video. The same video file perfectly works in Chromium as a control test. Example file is MP4, inside was initially h264 video with AAC audio, for test I re-encoded video to be svt-AV1 with AAC / flac as well - no difference, audio still lags behind. Local players (mpv) and Chromium works perfectly. No plugins which can affect it - for testing disabled them all. I really try hard to like Firefox but this thing is a real bummer. Any ideas what can be causing? P.S. I tested both firefox compiled from source and binary package provided by my distro. Linux system if that matters.

Whenever I'm watching YouTube and a video goes to the next, it resets back to default setting for the video. Is there a way to fix this? And I've tried to reset my cookies and site data, didn't work.

I have been looking for any "cast to device" button or setting on and off for a few weeks now and can't seem to find it. Not sure if it's just right out disabled in the browser (because other sites allow me to cast), but YouTube specifically just doesn't have the option anymore. Just wondering if it's something on my end or if it's fixable at all.