1767872 - Offscreen video starts with audio and neither mute in video nor mute on tab working

Status: RESOLVED WORKSFORME

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

Description

[Matthias Andree]

User Agent: Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:100.0) Gecko/20100101 Firefox/100.0

Steps to reproduce:

Ran Firefox 99 in safe mode, and then upgraded an Firefox 100 in normal mode, on Fedora Linux 35 x86_64, fully updated.

opened https://www.wmf.com/de/

At the time of this bug report, this website contained a video with such regional HTML
<div class="f-widget f-grid__cell-tile f-grid__cell f-grid__cell--6 f-grid--overflow">
<div class="wmf-video-wrapper">
<h3 style="font-family: Rotis II Sans,Arial,sans-serif;font-size: 20px;color: #1a1a1a;margin: 6px 0;border: none;padding: 0;">Kaffee-Glamour in München: das Event-Video</h3>
<video controls="" muted="" autoplay="" poster="https://www.wmf.com/media/wysiwyg/Kampagnenseiten/2022_04/wmf-aftermovie-cover_323px.jpg" width="100%"><source src="https://www.wmf.com/media/wmf_upload/videos/wmf-aftermovie-16X9__web.mp4" type="video/mp4">
</video>
<div class="wmfwidget-text-content"><div class="button-set u-text_c"><a class="button button-primary button--auto" href="https://perfection.wmf.com/de/perfection/weltpremiere-muenchen?utm_source=wmfshop&amp;utm_medium=internalpromo&amp;utm_content=widget-weltpremiere" target="_self">Mehr erfahren</a></div></div>
</div>
</div>

Actual results:

the web site loaded and started playing audio from a video.
ALTHOUGH the loudspeaker was stroked through and the volume bar in the embedded video controls were all the way to the left.
The Tab did NOT show a loudspeaker symbol, and toggling the mute on the video did not stop the audio. I could pause the video, however, to also stop audio, and I could also close the tab.

Expected results:

An off-screen video should never auto-start playing until it scrolled into view.
At the very least, the mute button should work properly and mute the video.

Comment 1

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

The Bugbug bot thinks this bug should belong to the 'Core::Layout: Text and Fonts' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[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 auto_nag documentation.

Comment 3

[Paul Adenot (:padenot)]

Thanks for the report. Reading the description, this looks clearly like a bug. I don't see a video on this page anymore, and I've reworked the muting and audio initialization code since then (quite recently, shipping in 101).

Matthias, I'm closing this because I can't reproduce and I've essentially rewritten this recently, but please make sure to comment and/or reopen this if you can still reproduce, we'll have a deeper look.

Comment 4

[Matthias Andree]

Paul, thanks for looking. I will report back if this happens again with newer Firefoxes.