Firefox doesn't display videos at 60 fps (the canvas only refreshes at 30hz?)
It's been more or less a month since firefox stopped displaying 60fps videos at 60fps. It says it's 60fps and doesn't show dropped frames, but you can clearly see it's only showing 30 fps. i've tried a bunch of things to no avail and decided to wait for an update to fix this. Well, i'm tired of waiting.
Just today i discovered that if the canvas is being scrolled or the firefox window being dragged, it displays 60fps properly. It only drops back to 30fps when i stop scrolling or moving the firefox window.
I've googled for a solution numerous times but i can't seem to find anyone with this exact same problem. So... how do i fix it? i think it started with either a firefox update or a windows update. I can't be sure because both happened pretty much at the same time. This doesn't happen to chrome or edge. Just firefox. i've already tried removing video drivers (with DDU) and reinstalling them, removing all my add-ons, and reinstalling firefox. Nothing works.
help.
All Replies (3)
You mentioned a canvas, which makes me think this is not your typical straight-up HTML5 <video> player we're talking about. Could you give an example of a page where you see this problem?
Well, i'm talking mostly about youtube. i think it affects videos from any page but i'm not 100% sure. anyway, i've only seen it affect video playback. Tested with daily motion and i can't seem to get 60fps in any video.
just tested on the only non-video 60fps+ site i could think of ( https://www.testufo.com/ ) and it properly displays the top test strip at 80 fps (my refresh rate is 80hz with freesync on, btw).
the interesting bit is that when i set youtube to play videos at 2x rate the video speeds up accordingly, showing 60 fps playback on the accelerated video. also, like i said, if i click mouse 3 and scroll down or up very slowly, the video displays properly at its correct frame rate too, as long as i don't stop scrolling. same for grabbing the browser window and slowly moving it around. none of this works in dailymotion, only on youtube.
i would like to stress this has worked fine for years on this setup with these settings, it just stopped working late last month, out of the blue.
i'm really at a loss here. why am i the only one having this issue?
I probably don't watch any 60fps videos, so you can't judge by my experience. You might also search the Firefox subreddit for recent issues with high frame rate videos: