1440971 - Short audio crackle from unfocused tab

Status: RESOLVED WORKSFORME

(Core :: Audio/Video: Playback, defect, P5)

Description

[Avinash]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:58.0) Gecko/20100101 Firefox/58.0
Build ID: 20180206200532

Steps to reproduce:

Open the following link a new tab and don't switching to that tab:
https://www.shadertoy.com/view/4tjGRh


Actual results:

After the page loads, a short crackling sound is heard from the video playing.


Expected results:

The video/audio should have started playing only after I switched to that tab.

Comment 1

[Ralph Giles (:rillian)]

Sounds like a job for block autoplay?

Comment 2

[Ralph Giles (:rillian)]

Sort of. Looks like shadertoy lets you generate audio waveforms in webgl and then handles playing them. I don't see any media elements in the about:media devtools panel, so presumedly it's using webaudio for the actual output. So the user experience is the same as with an autoplaying video in an untouched tab, but the mechanism is different.

What do you think about handling this, Chris?

Comment 3

[Ralph Giles (:rillian)]

At least the tab mute button works in this case.

Comment 4

[Chris Pearce [:cpearce (Not reading bugmail)]]

This is an artefact of how we do the delay playback start until tab focus. It would be a big job to rework that. Block autoplay would help here.

Comment 5

[Ralph Giles (:rillian)]

I guess we could crossfade when switching to the tab? That's still a fair bit of work. Hopefully the situation will improve with autoplay blocking, scheduled to ship later this year. Until this there's probably not much we can do.

Thanks for the report though. Neat demo!

Comment 6

[Avinash]

Tested on Firefox 89.0.1 (64-bit) on Windows 10 and the issue is resolved with the tab showing up as "AUTOPLAY BLOCKED".