1986170 - youtube.com - Firefox becomes unresponsive for a while after loading a YouTube video

Status: UNCONFIRMED

(Core :: Audio/Video: Playback, defect, P3)

Description

[Denys:denyshon]

Attachment: Firefox becomes unresponsive for a while after loading a YouTube video

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:142.0) Gecko/20100101 Firefox/142.0

Steps to reproduce:

I can't reproduce it on my other device, so some of the preconditions must be crucial. However, here the issue reproduces itself in a fresh profile. OS: Windows 10, Firefox MSiX 142.0.1. The issue is NOT reproducible in Edge on the same device. So, to reproduce:
Open any video on YouTube and play it (it doesn't matter whether you used YouTube before, whether you have other YouTube tabs opened and whether you are logged in).

Actual results:

Firefox becomes totally unresponsive for about 30 seconds. During that time, the audio is streamed fine, but the fps drops super low, and the UI is almost unresponsive (see the recording).
Please note that the audio has not been recorded.

Expected results:

The video starts playing immediately without any glitches.

Comment 1

[Denys:denyshon]

Also, I've been facing this bug for more than a year

Comment 2

[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 3

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

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

For more information, please visit BugBot documentation.