1888896 - Issue with bluetooth headphones that support either stereo sound (A2DP) or mono sound + microphone (HSP + HFP) on Windows

Status: NEW

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

Description

[Joel.Cedric]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:124.0) Gecko/20100101 Firefox/124.0

Steps to reproduce:

I am using a Windows laptop with a microphone connected by USB and a Bluetooth headset (Sennheiser Momentum 3 Wireless) connected through Bluetooth. The headset supports both, stereo sound (A2DP) and mono sound + microphone (HSP + HFP). I usually use the microphone connected by USB + stereo sound on my headset instead of mono sound and microphone both from the headset. I use this setup for web-calls (e.g. zoom, discord, jitsi, .....).

I am either using dedicated call clients for those calls (e.g. the software solutions by zoom, discord, skype), or alternatively, I use hosted web-versions of those platforms to join calls by browser.

I recently noticed that when I use Firefox to join such calls, the headphones don't appear as stereo (A2DP) audio output option in selector fields. They appear just as mono + microphone (HSP + HFP) option in audio input/output selector fields. When I use a Chrome-based browser (or any of the dedicated clients) instead, the Stereo option (just as output) as well as, mono + microphone (HSP + HFP) as input + output are available.

I tried zoom and Jitsi-Meet to verify if it is a web call platform bug or a browser bug. The Zoom client allows me to pick the Bluetooth headphones as stereo output, as well as use them with HSP + HFP for input/output. The Zoom web version as well as Jitsi-Meet web version, both accessed through a Chrome-based browser, allowed me to pick the Bluetooth headphones as stereo output, as well as use them with HSP + HFP for input/output. The Zoom web version as well as Jitsi-Meet web version, both accessed through Firefox, did not allow me to pick the Bluetooth headphones as stereo output, only HSP + HFP for input/output was available.

Actual results:

I am unable to pick my Bluetooth headphones as stereo output (A2DP) on Firefox on web-call platforms accessed by browser. They only appear as mono + mic (HSP+HFP) for input/output option.

Expected results:

I should be able to pick my Bluetooth headphones as stereo output (A2DP) on Firefox on web-call platforms accessed by browser.

Comment 1

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

The Bugbug bot thinks this bug should belong to the 'Core::Audio/Video: cubeb' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Paul Adenot (:padenot)]

I think I see what's going on.

We have some logic that uses the hands-free device on the output side if we find that the microphone on the same physical device has been picked for input (which isn't your case). If I recall correctly, this is both to have lower round-trip latency, but also to avoid issue on some devices, that had all sorts of errors when activating the microphone but also attempting to use the A2DP device at the same time (however it's been some time since then, my recollections might be incorrect).

I think in this particular case of a Bluetooth headset having a mic, that is not used, and two output devices (handsfree and A2DP), and also having another mic available (that is used), there's a bug in which our audio IO layer, where we fail to check what the device on the input side is in use, and switches the output side to the handsfree device under the hood. It might be related to which device is set as a default in the Windows settings (mmsys.cpl).

I've ordered some hardware to reproduce this, as I've recently switched my Windows system from a laptop (that had Bluetooth hardware) to a much more powerful desktop workstation (that doesn't have Bluetooth or wifi).

Comment 3

[Joel.Cedric]

That might be plausible; the A2DP device is my default audio output in windows.

Comment 4

[Paul Adenot (:padenot)]

Do you know what the default audio input device is / was? Both for "communication" and the "regular" default? I received the hardware today, I'll hopefully be able to have a setup that's similar enough and fix this soon.

Comment 5

[Joel.Cedric]

It took me some time to figure this out. In the new Windows audio settings UI the input and output was set to the USB Headset as input and the A2DP part of the headset as output. In this new UI the communication device doesn't seem to be an option anymore. However, through the old Windows audio settings UI I was able to identify that in this other UI the non-stereo part of the headset was set up to be the default communication device. After realizing this, I changed the A2DP to be also the default communication device. I restarted Firefox and tried with Zoom Web to see if the issue remained .... and I still wasn't able to select the A2DP as output.

Comment 6

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

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

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