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Issue 777443 link

Starred by 3 users

Issue metadata

Status: WontFix
Owner:
Closed: Oct 2017
Cc:
Components:
EstimatedDays: ----
NextAction: ----
OS: Linux
Pri: 2
Type: Bug



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Chrome auto-adjusts PulseAudioVolumeControl internal mic settings to incorrect ones

Reported by heathsim...@gmail.com, Oct 23 2017

Issue description

UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.62 Safari/537.36

Steps to reproduce the problem:
1. Open PulseAudio Volume control and move 'From left' all the way left, and keep 'From Right' higher (needed to get internal mic working. Lock channels.
2. Open Chrome and start teaching a class on Verbling, or using some other app or site that uses the internal mic.
3. Chrome automatically adjust the 'From Left' and From Right' sliders, making them equal, thus making my internal mic no longer work.

What is the expected behavior?
I do not want my AudioPulseVolumeControl settings for my internal mic auto adjusted.

What went wrong?
When Chrome auto adjusts my internal mic settings, my mic doesn't work. This happens during an online class, thus ruining my class. Firefox does not do this, and now I am forced to use Firefox.

Did this work before? N/A 

Chrome version: 62.0.3202.62  Channel: stable
OS Version: Ubuntu 17.10
Flash Version: 

I love Chrome, but I am forced to use Firefox. Just add a simple option to Chrome 'don't auto adjust internal mic settings'
 
Components: Blink>Media>Audio
Labels: Needs-Triage-M62
Components: -Blink>Media>Audio Internals>Media>Audio
Cc: maxmorin@chromium.org olka@chromium.org
I don't think we're doing anything intentional here, no idea why this would happen. Are you familiar enough with Pulse Audio to know which API controls this setting?

https://cs.chromium.org/chromium/src/media/audio/pulse/pulse_util.cc?l=270
Components: Blink>WebRTC>Audio
Owner: hlundin@chromium.org
This is the AGC, right?
The volume is set at https://cs.chromium.org/chromium/src/media/audio/pulse/pulse_input.cc?q=pulseaudioinput&l=167, and it's set to the same value for all the channels. I think it's quite uncommon to have a stereo mic requiring unequal gain for the channels? Not sure we should support this usecase.

Comment 6 by ossu@chromium.org, Oct 25 2017

Cc: ossu@chromium.org
This is quite interesting:
1. Why does the mic need to be configured like this to work? This sounds like the underlying problem. heathsims2011@: Could you elaborate on this? What microphone is it?
2. In general, I'd think our analog AGC is only developed with a single input in mind. Would there perhaps be other cases where the relative levels of channels should be retained when changing hardware gains?

Comment 7 by olka@chromium.org, Oct 25 2017

heathsims2011@ could you disable flat volumes in PulseAudio and see how it works then?

Comment 8 by olka@chromium.org, Oct 25 2017

re#6: For both Win and Mac we adjust master channel volume, I hope it keeps channels balance.

Comment 9 by olka@chromium.org, Oct 25 2017

To disable flat volumes: add
flat-volumes = no
to ~/.config/pulse/daemon.conf


Labels: Needs-Feedback Triaged-ET
As per C#9 could you please disable flat volumes in Pulse Audio and provide your observation 
Cc: aleloi@chromium.org alessiob@chromium.org
alessio@, aleloi@, FYI

Comment 12 by aleloi@google.com, Oct 25 2017

re#4, #3:
There is a call chain from the WebRTC AGC starting here (https://cs.chromium.org/chromium/src/content/renderer/media/webrtc/processed_local_audio_source.cc?l=317) to pa_cvolume_set which maxmorin@ posted in #3. So yes, this is the AGC. I don't think there is a way to disable it for a user; you'd have to pass different constraints to GetUserMedia from the application JS.
Status: WontFix (was: Unconfirmed)
I don't think we can design around "mic that requires uneven channel volume to function" as a use case, so I'm closing this as WAI.

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