[alsa-devel] asihpi: Control naming

[Raymond Yau]

2010/10/1 Sebastian H. <vand2 at gmx.de>

> Am 01.10.2010 09:05, schrieb Clemens Ladisch:
> > Sebastian H. wrote:
> >> In alsamixer-qt4 I've just stumbled over enum elements for which both
> >> snd_mixer_selem_is_enum_playback and
> >> snd_mixer_selem_is_enum_capture
> >> return 0/false (2.6.32 kernel emu10k1 chip).
> >>
> >> May I drop the question in if this state can be considered valid
> >
> > Yes.
> >
> >> and besides *playback* and *capture* elements there's a third group of
> >> *neutral* elements?
> >
> > 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.
>
> 1) There's a bug or uncertainty somewhere in the libs/driver and
> in a perfekt world this would not happen. It always should be either.
>
> 2) This is intentional and the respective element belongs to the
> group of *general* elements which exists in parallel
> to the *playback* and the *capture* element groups.
>
> As mentioned alsamixer-qt4 considers 1) and handles it somehow
> gracefully. I just wonder if that is the correct thing to do in case.
>

But the number of control related to capture is limited

1) Capture Volume
2) Capture Switch
3) Capture Source
4) Input Source
5) Mic Boost
6) ADC attenuation

Most of the other controls are related to playback