1905888 - Video in background tab randomly continuous playing even when not interacting with Firefox

Status: NEW

(Web Compatibility :: Site Reports, defect, P3)

Description

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:127.0) Gecko/20100101 Firefox/127.0 ID:20240520091901 and Shokz OpenRun as headset.

Since yesterday, I've noticed that Firefox is randomly continuing the playback of a video in a background tab that was previously paused. This happens even when Firefox is not in focus or is minimized to the dock. The situations where this occurred were:

• During a Zoom video call while I was actively speaking (which was quite annoying because I couldn't find the tab playing the video/audio to mute it)
• Working with a different Firefox instance (and profile) and exactly when clicking the left mouse button to press a button on Bugzilla
• Watching another video in a different tab of Firefox

So far, I haven't identified any specific trigger for this behavior. It happens even when I haven't touched my headset's play/pause button.

The video for which this has already happened three times, and which is always in the background, is: https://www.waterislovefilm.org/clips. Maybe there is some bug on that website which might cause that behavior given that I haven't seen it anywhere else yet?

Not sure if letting the Gecko profiler record a profile all the time (1s interval) will catch it, maybe we have markers that might be helpful? Please let me know and I could try to get a profile if wanted.

Comment 1

[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.

Comment 2

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Additionally, this typically occurs around 2-3 times a day at random intervals. I haven't been able to identify any specific activities on the machine that coincide with these occurrences but it's suspicious that this only happens on that particular website and no-where else yet.

Comment 3

[Henrik Skupin [:whimboo][⌚️UTC+1]]

One interesting observation I just made is that the video playback always starts from the beginning, even when it was paused a few minutes into the playback. It seems something might be resetting the duration and causing the automatic playback to restart from the beginning.

Comment 4

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Dennis and I just experienced the same behavior at the exact same time, even though we are not located near each other. The video automatically started playing around 15:43 (MESZ).

Comment 5

[Dennis Schubert [:denschub]]

This is the kind of report that sometimes make me question my own sanity.

Anyway. I have the JS tracer running in the background now, I'm hoping I can catch the next instance of the video playing itself, at which point we'd at least know which JS lead to it. For now, I'll treat this as a WebCompat bug, because that's kinda what it feels like.