Re: Sound input source detected but not capturing

[Marko Randjelovic <markoran@eunet.rs>]

On Sat, 04 Sep 2021 07:47:02 +0530
Pankaj Jangid <pankaj@codeisgreat.org> wrote:

> Marko Randjelovic <markoran@eunet.rs> writes:
> 
> > Did you make sure:
> >
> > 1. correct device is set to record from 
> > 2. recording is enabled
> > 3. input volume is large enough  
> 
> I guess I have only one device so there is nothing to set.

I meant 'input source'. On my machine it can be:

'Rear Mic' 'Front Mic' 'Line' 'CD'

> 
> How is recording enabled? Do I need to add myself to some group? I am
> member of followin groups: pankaj cdrom floppy sudo audio dip video
> plugdev netdev bluetooth scanner.

You are member of audio group, so that's fine. By 'recording enabled I
meant on/off switch.

> 
> I have tried to set input volume using various knobs in gnome settings
> as well as alsamixer. It did not work.
> 
> >> If you are not sure send the output of command 'amixer' so we can check.  
> >
> > In fact, unless you have only one sound device, the command should
> > be 'amixer -cN' where N is the number of your sound card and can change
> > after reboot. So first you have to type 'cat /proc/asound/cards' to
> > find your card number.  
> 
> Output of ‘amixer’
> 
> --8<---------------cut here---------------start------------->8---
> $ amixer
> Simple mixer control 'Master',0
>   Capabilities: pvolume pswitch pswitch-joined
>   Playback channels: Front Left - Front Right
>   Limits: Playback 0 - 65536
>   Mono:
>   Front Left: Playback 64880 [99%] [on]
>   Front Right: Playback 64880 [99%] [on]
> Simple mixer control 'Capture',0
>   Capabilities: cvolume cswitch cswitch-joined
>   Capture channels: Front Left - Front Right
>   Limits: Capture 0 - 65536
>   Front Left: Capture 65540 [100%] [on]
>   Front Right: Capture 65540 [100%] [on]
> --8<---------------cut here---------------end--------------->8---
> 
> Output of ‘amixer -c0’
> 
> --8<---------------cut here---------------start------------->8---
> $ cat /proc/asound/cards
>  0 [PCH            ]: HDA-Intel - HDA Intel PCH
>                       HDA Intel PCH at 0xb1328000 irq 137
> 
> $ amixer -c0
> Simple mixer control 'Master',0
>   Capabilities: pvolume pvolume-joined pswitch pswitch-joined
>   Playback channels: Mono
>   Limits: Playback 0 - 87
>   Mono: Playback 87 [100%] [0.00dB] [on]
> Simple mixer control 'Headphone',0
>   Capabilities: pvolume pswitch
>   Playback channels: Front Left - Front Right
>   Limits: Playback 0 - 87
>   Mono:
>   Front Left: Playback 0 [0%] [-65.25dB] [off]
>   Front Right: Playback 0 [0%] [-65.25dB] [off]
> Simple mixer control 'Speaker',0
>   Capabilities: pvolume pswitch
>   Playback channels: Front Left - Front Right
>   Limits: Playback 0 - 87
>   Mono:
>   Front Left: Playback 87 [100%] [0.00dB] [on]
>   Front Right: Playback 87 [100%] [0.00dB] [on]
> Simple mixer control 'PCM',0
>   Capabilities: pvolume
>   Playback channels: Front Left - Front Right
>   Limits: Playback 0 - 255
>   Mono:
>   Front Left: Playback 254 [100%] [-0.20dB]
>   Front Right: Playback 254 [100%] [-0.20dB]
> Simple mixer control 'Mic Boost',0
>   Capabilities: volume
>   Playback channels: Front Left - Front Right
>   Capture channels: Front Left - Front Right
>   Limits: 0 - 3
>   Front Left: 3 [100%] [30.00dB]
>   Front Right: 3 [100%] [30.00dB]
> Simple mixer control 'IEC958',0
>   Capabilities: pswitch pswitch-joined
>   Playback channels: Mono
>   Mono: Playback [off]
> Simple mixer control 'IEC958',1
>   Capabilities: pswitch pswitch-joined
>   Playback channels: Mono
>   Mono: Playback [on]
> Simple mixer control 'IEC958',2
>   Capabilities: pswitch pswitch-joined
>   Playback channels: Mono
>   Mono: Playback [on]
> Simple mixer control 'IEC958',3
>   Capabilities: pswitch pswitch-joined
>   Playback channels: Mono
>   Mono: Playback [on]
> Simple mixer control 'IEC958',4
>   Capabilities: pswitch pswitch-joined
>   Playback channels: Mono
>   Mono: Playback [on]
> Simple mixer control 'Capture',0
>   Capabilities: cvolume cswitch
>   Capture channels: Front Left - Front Right
>   Limits: Capture 0 - 63
>   Front Left: Capture 63 [100%] [30.00dB] [on]
>   Front Right: Capture 63 [100%] [30.00dB] [on]
> Simple mixer control 'Auto-Mute Mode',0
>   Capabilities: enum
>   Items: 'Disabled' 'Enabled'
>   Item0: 'Enabled'
> Simple mixer control 'Internal Mic Boost',0
>   Capabilities: volume
>   Playback channels: Front Left - Front Right
>   Capture channels: Front Left - Front Right
>   Limits: 0 - 3
>   Front Left: 0 [0%] [0.00dB]
>   Front Right: 0 [0%] [0.00dB]
> --8<---------------cut here---------------end--------------->8---
> 

Your control 'Capture',0 is turned on and volume is at maximum, so
that's fine, but you don't have 'input source' control. On my machine
output of 'amixer -c0' gives among other controls the following:

Simple mixer control 'Input Source',0
  Capabilities: cenum
  Items: 'Rear Mic' 'Front Mic' 'Line' 'CD'
  Item0: 'Rear Mic'

I suppose this is the reason why your capture is not working, but don't
know how to fix it. You might try to install kernel 5.13 from
experimental or newest vanilla stable which is currently 5.14.1 (take
care not to make your system unbootable). Also you might try with newer
alsa userland software.