[pulseaudio-discuss] module-echo-cancel microphone gain auto-adjust

Vasco Almeida vascomalmeida at sapo.pt
Sat Mar 4 18:41:23 UTC 2017

A terça-feira, 21 de fevereiro de 2017 08:51:14 AZOT Vasco Almeida escreveu:
> Hello.
> I know that module-echo-cancel used to auto-adjust the gain of
> microphone while one speaks. I used to see in pavucontrol the slider
> move change the microphone gain. Now I don't see that happen anymore.
> Was this feature removed or disabled?
> I see this new behavior in Fedora 25 and OpenSUSE Tumbleweed.
> How can I have microphone gain auto-adjust again?
> I have searched a little to see what I could find about the issue but I
> found nothing. This may be something new.
> Please reply to me because I am not subscribed to the list.
> Thank you.

pulseaudio 10.0
pactl load-module module-echo-cancel aec_method=webrtc
pactl load-module module-echo-cancel aec_method=webrtc 
or without aec_method or other arguments.
So far I could see the microphone slider move left only when the gain is 100% 
and I yell. When I set the gain to low the slider does not move at all to pick 
my voice.
On fedora 24 automatic gain control for microphone with module-echo-cancel 
works fine. On fedora 24 at the time of writing there is 

From PulseAudio 9.0 release notes [1]
> It's now possible to configure the initial volume when using AGC (automatic
> gain control). To do that, pass "agc_start_volume=VOL" in aec_args when
> loading module-echo-cancel (replace VOL with a number between 0 and 255).
> Note that too low initial volume may prevent the AGC algorithm from ever
> raising the volume high enough (there seems to be some regression in the
> WebRTC code in this regard).

Would the above change affect the automatic gain control that it does not work 
for me anymore?

[1] https://www.freedesktop.org/wiki/Software/PulseAudio/Notes/9.0/

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