Open Bug 1839040 Opened 2 years ago Updated 2 years ago

YouTube video playback is jittering/micro-stuttering

Categories

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

Product:
Core
Component:
Audio/Video: Playback
Version:
Firefox 114
Type:
defect

Tracking

()

Status:
UNCONFIRMED

People

(Reporter: maxim.safarov, Unassigned, NeedInfo)

Details

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/114.0

Steps to reproduce:

Play 1440p, 4k videos in youtube with hardware video decoding enabled (default settings). Panning shots show sttutering, unevenness of motion. Disabling hardware decoding (media.hardware-video-decoding.enabled = false) solves the issue. Chrome on the same machine doesn't have the issue. Hardware AMD 5600x and ATI 6800XT on Windows 10 21H2.

Actual results:

Panning shots show sttutering, unevenness of motion.

Expected results:

Smooth playback as in software decoding mode.

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.

Component: Untriaged → Audio/Video: Playback
Product: Firefox → Core

seems like keeping hardware decoding on and setting media.wmf.dxva.d3d11.enabled to false also improves video playback

The severity field is not set for this bug.
:jimm, could you have a look please?

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Flags: needinfo?(jmathies)

I can confirm the micro-stuttering issue is present on my side too when playing 4k video on Youtube, this doesn't happen on Edge.

Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/115.0

In my case media.hardware-video-decoding.enabled=true and media.wmf.dxva.d3d11.enabled=false help as the other user suggested. However with this setup the GPU activity seem to be 0 and the CPU sits at ~8%, on Edge these figures read as GPU ~60% and CPU 2%.

Can you guys test if disabling "media.wmf.low-latency.enabled" fixes it for you? It does for me. Might need nightly, in stable I think it's "media.wmf.low-latency.force-disabled".

I should have mentioned before, I'm on Windows 11 and with 6900XT and 5900X.

I tried with these settings but the stuttering persists:

  • media.hardware-video-decoding.enabled=true
  • media.hardware-video-decoding.force-enabled=true
  • media.wmf.low-latency.force-disabled=true

I'm using this video to test: https://www.youtube.com/watch?v=bgqGdIoa52s
Can this profile help? https://share.firefox.dev/3Dvn56S

Ah, I can sort of reproduce it even with low-latency disabled. I don't see any stuttering but it's certainly not smooth like Edge, like frame-pacing goes haywire or something. I do see rather high CPU use when it happens in the profile but idk if it's the same issue.

I can't reproduce it with wmf disabled with "media.wmf.vp9.enabled". CPU/GPU use seems higher and it's not using the decoder at all but rather the 3d engine :/ Not sure how viable it is at 8k60 then again Youtube tries to play it with AV1 which obviously doesn't work anyway...

Possibly a duplicate of https://bugzilla.mozilla.org/show_bug.cgi?id=1684662 -- @Maxim can you check?

Flags: needinfo?(maxim.safarov)
Severity: -- → S3
Flags: needinfo?(jmathies)
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