[alsa-devel] Record stereo from one input on the soundcard

[Pavel Hofman]

Dne 27. 01. 19 v 19:35 Tomas Nordin napsal(a):
> Here is the output of that:
> 
> $ amixer -c 1 contents
> numid=2,iface=PCM,name='Capture Channel Map'
>    ; type=INTEGER,access=r----R--,values=2,min=0,max=36,step=0
>    : values=0,0
>    | container
>      | chmap-fixed=FL,FR
> 
> numid=1,iface=PCM,name='Playback Channel Map'
>    ; type=INTEGER,access=r----R--,values=2,min=0,max=36,step=0
>    : values=0,0
>    | container
>      | chmap-fixed=FL,FR
> 
> And I didn't mention that in my original post but, alsamixer has been
> informing me that "This soundcard does not have any controls." when I
> select the AudioBox via F6.

That usb audio device seems to offer no feature controls:

https://forums.freebsd.org/threads/presonus-audiobox-usb-not-recognized.61395/#post-353537

Alsamixer lists only controls of type MIXER, while amixer lists all - 
incl. those of type PCM added by alsa-lib for your soundcard.

https://android.googlesource.com/kernel/common/+/android-trusty-3.10/Documentation/sound/alsa/Channel-Mapping-API.txt

Regards,

Pavel.