1936025 - AV1/VP9 Video frames flashing at the wrong timing on Windows

Status: RESOLVED DUPLICATE of bug 1936047

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

Description

[Joao Guerra]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:135.0) Gecko/20100101 Firefox/135.0

Steps to reproduce:

With the latest Firefox Nightly,
on the YouTube videos:
https://www.youtube.com/watch?v=h9a0PbD3esI (AV1)
https://www.youtube.com/watch?v=HWOzx_hIGZs (VP9)
and also on this twitch AV1 video:
https://www.twitch.tv/videos/637388605

Actual results:

The video playback is not smooth: some frames are flashing before their supposed time.

h264 playback seems to be unaffected.

Expected results:

Video playback should be smooth, with frames being presented in their proper order.

Setting media.ffvpx-hw.enabled to false fixes the issue, while the video is still hardware decoded (Video Codec 0 in the Task Manager shows activity).

Profiler logs, with the "Media playback" preset, of the first (AV1) YouTube video - paused at around 0:14, played until around 0:20 and paused again:
https://share.firefox.dev/4ikNaZH - media.ffvpx-hw.enabled set to true
https://share.firefox.dev/3ONaVvS - media.ffvpx-hw.enabled set to false

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

[David Smith]

I'm seeing the same issue. Most YouTube videos seem to have moderate out-of-order playback issues (a few frames every few seconds), while the provided Twitch video listed by the OP, plus another YouTube video (https://www.youtube.com/watch?v=2uLGXe95kTo) have far more extreme playback issues (multiple instances per second), and fail to playback any video at all after the screen is scrolled on my main profile (but not on a fresh profile).

Likewise not seeing playback issues with h264 videos.

Comment 3

[Mayank Bansal]

Dupe of bug 1936047?