[alsa-devel] asihpi: Control naming

Raymond Yau superquad.vortex2 at gmail.com
Sat Oct 2 06:10:26 CEST 2010


2010/10/2 Sebastian H. <vand2 at gmx.de>

> Am 01.10.2010 15:19, schrieb Clemens Ladisch:
> > Sebastian H. wrote:
> >> Am 01.10.2010 09:05, schrieb Clemens Ladisch:
> >>> Those are elements where the simple mixer code doesn't know the
> >>> direction (because the driver author didn't put "Playback" or "Capture"
> >>> into the name).
> >>
> >> Ok, but I wonder how to interpret this state in which both functions
> >> return zero.
> >
> > There are cases where the playback/capture direction is obvious from the
> > name ("just implement an AI!"), but these can be considered bugs.
>
> Ok, I'll stick to the element name list from Raymond then for an
> automated detection.
>

I just only mention the keywords in those capture controls in sound card
drivers.
They may have slightly different name (e.g. 'Mic Boost (+20dB)' , 'Front Mic
Boost' )


In simple_none.c , it also defined some keywords for stanard ac97 control
too

some of them are used (e.g. "3D Control - Switch" is regarded a pswitch) but
"Depth and Rear Depth are regarded as volume )


Simple mixer control '3D Control - Switch',0
  Capabilities: pswitch pswitch-joined penum
  Playback channels: Mono
  Mono: Playback [off]
Simple mixer control '3D Control Sigmatel - Depth',0
  Capabilities: volume volume-joined penum
  Playback channels: Mono
  Capture channels: Mono
  Limits: 0 - 3
  Mono: 0 [0%]
Simple mixer control '3D Control Sigmatel - Rear Depth',0
  Capabilities: volume volume-joined penum
  Playback channels: Mono
  Capture channels: Mono
  Limits: 0 - 3
  Mono: 0 [0%]

They are just 3D effect and have no dB information.

However alsa-python return run-time error when you try to use the function
get_volume_range_dB() to find out whether the mixer elem has dB Info or not



>
> > In the other cases, the control really doesn't belong to a direction.
> > (Which doesn't prevent many mixers that have two pages from just
> > throwing them in with the playback controls.)
>
> Bringing up a separate page for rare *general* elements doesn't seem
> worthwile then and the *playback* page should be fine.
>
> Cheers,
> Sebastian
>
>


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