[pulseaudio-discuss] Mute mic output keeping its input working

[David Henningsson]

On 2011-07-04 14:04, Marcos Felipe Rasia de Mello wrote:
> 2011/7/4 David Henningsson<david.henningsson at canonical.com>:
>>
>> This should be the default.
>>
>>
>> It is probably a matter of your sound card being old (and unknown) rather
>> than a general problem.
>>
>>
>> Could you supply an alsa-info (wiki.ubuntu.com/Audio/AlsaInfo) to tell us a
>> little more about your hardware?
>>
>
> Thank you, David, for the information.
>
> alsa-info.sh output attached.
>
> What I've tried so far:
> 1 - enable mic bost (very important!) using "alsamixer -c 0", because
> there's no switch that controls that in Gnome volume control.
> 2 - pactl set-source-mute
> alsa_output.pci-0000_03_05.0.analog-stereo.monitor 1 (didn't help)
>
> Regards,
>
> Marcos

Well, it seems that there is something wrong with the ALSA driver, 
because you have correctly set the "Mic" volume (in the below, 
"Playback" is correctly set to "off" and "Capture" to "on". That should 
have been enough to prevent feedback IMO. I'm not an AC'97 expert though.

Simple mixer control 'Mic',0
   Capabilities: pvolume pvolume-joined pswitch pswitch-joined cswitch 
cswitch-exclusive penum
   Capture exclusive group: 0
   Playback channels: Mono
   Capture channels: Front Left - Front Right
   Limits: Playback 0 - 31
   Mono: Playback 0 [0%] [-34.50dB] [off]
   Front Left: Capture [on]
   Front Right: Capture [on]

-- 
David Henningsson, Canonical Ltd.
http://launchpad.net/~diwic