1295050 - Firefox audio being misclassified as "communications" in Windows mixer

Status: NEW

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

Description

[(No longer employed by Mozilla) Aaron Klotz]

A reddit user is reporting that when Firefox plays audio, other sources are being attenuated. According to the reddit user, the Firefox audio is being classified as communications audio, so it is being prioritized by the mixer over the background audio.

https://www.reddit.com/r/firefox/comments/4x461y/how_do_i_make_ff_not_decrease_background_audio/d6cd2ik

Obviously some of our audio *is* communications (WebRTC), but other types of audio should probably not be classified as such.

Comment 1

[Maire Reavy [:mreavy]]

Matthew -- What would we need to do to fix this?

Comment 2

[Matthew Gregan [:kinetik]]

I'm not sure yet.  I've asked for a bit more info in the Reddit thread.

If it's only affecting MSG-based audio and not regular playback, it might be a side effect of the device selection code that was added as part of the full-duplex work.

For default output devices, in 48 and earlier (before bug 1266623 landed), we opened devices with the eMultimedia role.  After that bug landed, we switched to the eConsole role.  We never request devices for the eCommunications role, which is what I'd expect to trigger the audio ducking.

We can explicitly opt in and out of audio ducking with IAudioSessionControl2::SetDuckingPreference, so if that's necessary to fix this it's a pretty simple change.

Comment 3

[Matthew Gregan [:kinetik]]

No reply on Reddit, and I don't see this behaviour locally on Windows 10 AU.

Comment 4

[(No longer employed by Mozilla) Aaron Klotz]

Another report on reddit:
https://www.reddit.com/r/firefox/comments/569w8c/sounds_in_firefox_automatically_pause_windows/

Comment 5

[Emma Humphries ☕️🎸🧞‍♀️✨ (she/they) [:emceeaich] (Pacific Time) use needinfo]

This is a P1 bug without an assignee. 

P1 are bugs which are being worked on for the current release cycle/iteration/sprint. 

If the bug is not assigned by Monday, 28 August, the bug's priority will be reset to '--'.

Comment 6

[Bulk Bug Changes for mreavy's org]

Mass change P1->P2 to align with new Mozilla triage process

Comment 7

[Anthony Jones (:ajones, :kentuckyfriedtakahe, :k17e)]

Please ni? if you have a repro for this issue.