[alsa-devel] snd-usb-audio issues??

Richard Storer rstorer at ntlworld.com
Mon Apr 14 16:40:13 CEST 2014

Hi Takashi, thanks for the info regarding live24ext_map.
I read the comments "the card may adjust microphone input level only."
but I do not understand.

Does this mean my device lacks hardware control for Line-In??

Does the Windows driver providing Line-In levels with software emulation??

I am a little confused here.

Richard S.

On 14/04/2014, Richard Storer <rstorer at ntlworld.com> wrote:
> From what I can tell with the Windows driver Mic-In and Line-In share
> the same mixer slider control, this may explain why only 1 capture
> control appears under Linux.
> I have tried adjusting the Mic levels while capturing audio but only
> the Mic levels change the Line-In levels do not change at all.
> Could this be confusing the driver somehow??
> Richard S.
> On 14/04/2014, Clemens Ladisch <clemens at ladisch.de> wrote:
>> Richard Storer wrote:
>>>         bTerminalID             4
>>>         wTerminalType      0x0603 Line Connector
>>>         bDescriptorSubtype      6 (FEATURE_UNIT)
>>>         bUnitID                 5
>>>         bSourceID               4
>>>         bmaControls( 0)      0x02
>>>           Volume Control
>> That single capture mixer control controls the line input.
>> (I don't know why it's labelled as "Mic", or how the device
>> switches between mic and line signal levels.)
>> Regards,
>> Clemens

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