[LAU] How to prevent applications from changing my mic level?

[Bill Purvis]

On 06/05/2020 17:15, Len Ovens wrote:
> On Wed, 6 May 2020, S. wrote:
>
>> So you seem to be suggesting that Pulse is directly responsible for
>> manipulating the levels? I assumed that it was Chromium and its spinoffs
>> (Chrome and Electron apps), using an AGC function specifically as 
>> part of
>> the WebRTC protocol:
>
> Pulse poses as an alsa device to the application so that more than one 
> application can use the same device at the same time. So chrome 
> controls it's device which is pulse and pulse satisfies the request 
> with either direct device manipulation or digital if direct is not 
> possible (or if there is more than one application using that device).
>
>> Thanks for confirming this option, I had found a similar suggestion 
>> here:
>> https://askubuntu.com/questions/689209/how-to-disable-microphone-volume-auto-adjustment-in-cisco-webex/761103#761103 
>>
>> That looks like the solution I was hoping for of making it not 
>> possible for
>> processes to mess with the mic gain. But unfortunately the profiles are
>> under /usr/share/ , so the tweaks will be reverted every time Pulse is
>> updated... :-(
>
> As with all things Linux these days, configuration can be done in more 
> than one place. While I am sure that an added profile file with a 
> unique name would not interfere with upgrades even in /usr/share, 
> quite probably the default profile could be overridden in 
> /etc/pulse/*/ and failing that, there is always ~/.local/share/ to 
> play with. Really, it is all about seaking documentation and examples 
> to work from. If you only have one user on the system, copying the 
> file from:
> /usr/share/pulseaudio/alsa-mixer/paths/analog-input-internal-mic.conf
> to:
> ~/.local/share/pulseaudio/alsa-mixer/paths/analog-input-internal-mic.conf
> and editing it there may be just as effective.
>
> As before, I have not personally tried this as jack already fixes it 
> for me.
>
> -- 
> Len Ovens
> www.ovenwerks.net
This thread prompted me to look at it. I tried

     pacmd set-default-sink jack_out

which does the trick, assuming you have the pulseaudio-jack module loaded.
Having got there, adding the command to the end of 
/etc/pulseaudio/default.pa
should make it set that whenever it starts up. I've yet to try that as I 
don't
reboot more often than necessary.

Bill

-- 
+----------------------------------------+
| Bill Purvis                            |
| email: bill at billp.org                  |
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