1896044 - Youtube streams (1080p60fps) and certain browser videos become laggy/choppy after awhile

Status: RESOLVED DUPLICATE of bug 1890622

(Core :: Audio/Video: Playback, defect)

Description

[Chobits1717]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:125.0) Gecko/20100101 Firefox/125.0

Steps to reproduce:

Basically, just watch high-quality and high framerate videos and performance will start to drop after awhile.

Actual results:

Firefox isn't having a memory leak (RAM and CPU usage stays the same) nor is it maxing my GPU or anything like that. But if I watch enough of a 1080p60fps stream or enough 1080p60fps content in general (this stream is a notable offender: https://www.youtube.com/watch?v=W6OOnrx8g58), it'll start to slow down over time (generally a couple of hours) and really chug and drop frames like its nobody's business: https://i.imgur.com/OmHqJ8a.png. This does not occur in Edge (the streams run silky smooth even after 2+ straight hours of watching in that browser), nor does it happen on other streaming sites like Twitch. It also doesn't happen in Firefox on my desktop.

Regular 1080p60fps videos are MOSTLY unaffected. The buffer wheel animation in most videos is choppy and moving back/forth with the 5-sec rewind/ff feature results in a short, choppy buffer wheel on a lot of videos(https://imgur.com/tm1AtkB), even if the video itself is mostly unaffected. Some more "intense" videos will make the fan speed go up. HD videos are slightly less smooth when in this state. Unpausing a video often results in a short buffer wheel before the video resumes if left paused for at least a minute or so. I also get a tiny TINY bit of frameskip on the occasional Twitter video while in this "state".

Its like the memory is "caching" something and killing the process clears that "cache", yet I have no idea what is actually doing this.

Refreshing the page/closing and reopening the stream stream has no effect, its like an affliction and will still be choppy when you reload. Restarting the Firefox session or killing the process the stream or a video is running through fixes it for awhile (even if the stream stilll drops more frames overall than it would in Edge), but it feels like I have an "allowance" of 1080p60fps content before these streams start to chug. Nothing else in-browser is lagging at all.

Expected results:

Firefox shouldn't be dropping frames like this when other browsers aren't, and there shouldn't be continual performance degradation

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Audio/Video: Playback' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Alastor Wu [:alwu]]

It sounds like bug 1890622. Would you mind to post your about:support? If it's the same issue, a temporary workaround is to disable gfx.direct3d11.reuse-decoder-device.

Comment 3

[Chobits1717]

Attachment: About Support

(In reply to Alastor Wu [:alwu] from comment #2)
> It sounds like bug 1890622. Would you mind to post your `about:support`? If it's the same issue, a temporary workaround is to disable `gfx.direct3d11.reuse-decoder-device`.

It could very well be that. Does Youtube decode through DX11?

It also explains why it happens on my Intel Iris Graphics Xe laptop, but not on my RTX 3070ti Desktop.
Though I took a look at that thread and it mentions the issue might be Gen 12 Intels, but my laptop uses a Gen 13 Intel. Still could be being hit by the same problem, though.

My about:support is attached

Comment 4

[Chobits1717]

About:Support is attached. Does the decoder run through a Firefox process? The performance gets (mostly) reset back to where it should be if I kill a particular process.

Comment 5

[Alastor Wu [:alwu]]

(In reply to Chobits1717 from comment #4)

About:Support is attached. Does the decoder run through a Firefox process? The performance gets (mostly) reset back to where it should be if I kill a particular process.

On Windows, hardware decoding happens on GPU process, if kill GPU process helps, then I think it's the same problem with bug 1890622, even if you're using gen13. Let's close this bug and put all discussion on bug 1890622.