1352557 - media.navigator.audio.full_duplex broken on Linux with Alsa

Status: RESOLVED WONTFIX

(Core :: WebRTC: Audio/Video, defect)

Description

[roblabla]

Steps to reproduce:

1. Install QubesOS
2. Run firefox inside one of the Qubes VM.
3. Go to https://jsfiddle.net/W569n/3/
4. Press "click here to start stream"


Actual results:

An error comes up : NotFoundError: The object can not be found here

Expected results:

Firefox should be able to find the audio input streams properly and ask the user which one to share with the page.

Comment 1

[roblabla]

Thanks to some help on IRC, I've been able to pinpoint the problem to an interaction between ALSA and the media.navigator.audio.full_duplex option. If I disable this option, firefox starts acting as expected. I have a patch written that deactivate full_duplex when FF is compiled with USE_ALSA.

Comment 2

[Byron Campen [:bwc]]

Not sure who was involved in the IRC conversation mentioned in comment 1.

Comment 3

[Randell Jesup [:jesup] (needinfo me)]

That was me, in #firefox

Comment 4

[Andreas Pehrson [:pehrsons]]

So, official Mozilla builds of Firefox don't come with full duplex alsa support, nor will they in the future. Thus a wontfix.

But there is code to support it in our audio backend, [1], and I understand that some linux distros already build their Firefox releases with alsa support enabled. You can enable alsa for your own local build by adding `ac_add_options --enable-alsa` to your ".mozconfig" file.

Don't expect non-full-duplex to work for much longer, with alsa or otherwise.

Are there issues with the full-duplex alsa implementation, patches are accepted against cubeb, again, the repo at [1].

[1] https://github.com/kinetiknz/cubeb/blob/52b467d4f0993eb3949d97934aa254b0522bd0a9/src/cubeb_alsa.c#L1006