www.youtube.com - video or audio doesn't play

[jomuyo]

URL: https://www.youtube.com/watch?v=krMPnGHirLk&t=49s

Browser / Version: Firefox 126.0
Operating System: Mac OS X 10.15
Tested Another Browser: Yes Other

Problem type: Video or audio doesn't play
Description: The video or audio does not play
Steps to Reproduce:
Most of the YouTube videos that are using 1080p Premium and 4K resolutions either will not play with a spinning wheel graphic or plays for a moment then pauses with the spinning wheel. Refreshing the page didn't work. Clicking just before or after the trouble spot on the timeline also didn't work. I am also seeing the same issue on some videos with the 1440p resolution where in the past videos would play fine at that resolution. All of these problems went away when I set the "gfx.webrender.compositor" setting to "false" in about:config. This issue came up in the previous 125.0 release, and in prior releases I didn't experience this issue. I have tested the same videos in Vivaldi and Safari and there were no playback issues in those higher resolutions.

Browser Configuration

• None

From webcompat.com with ❤️

[jomuyo]

Just as an update. I just did a Firefox refresh to see if resetting everything would also fix the issues I am having with YouTube. The video I was watching with 1080p Premium (https://www.youtube.com/watch?v=v2Oa2fHgIxo) is now playing well. However on 4K videos, like the one linked above, the video can get unstable. Like if you advance forward or back to other chapters in the timeline, you can get the video to freeze and even lock up the play/pause button. I have noticed that the grey buffer portion of the timeline is noticeably shorter than some of the lower resolution videos. There are some 4K videos that perform better like this one: https://www.youtube.com/watch?v=hzzpaibSeak. By clicking around that video, you can get it to freeze the video while the auto is not playing, and after some time will resolve itself. I have also tried resetting the "gfx.webrender.compositor" setting to "false" after I did the Firefox refresh, however this time it didn't resolve the playback issues.

[sv-calin]

We appreciate your report but this is a known issue.

Closing as duplicate of https://bugzilla.mozilla.org/show_bug.cgi?id=1878016

[qa_23/2024]