[alsa-devel] Verifying mixer dB data/Invalid dB data from USB cards, especially Aureon 5.1 MkII

[Raymond Yau]

2010/2/22 Lennart Poettering <mznyfn at 0pointer.de>

> On Sun, 21.02.10 11:49, Raymond Yau (superquad.vortex2 at gmail.com) wrote:
>
> > The most common onboard audio is HDA so this is not any exceptional cases
> >
> > Those HDA multi streaming  feature are most users wanted in desktop
> > enviornment, are pulseaudio really designed for deskop or just only for
> > notebook and mobile ?
> >
> > The front panel green/pink jack can be used by one application while the
> > rear panel audio jacks can be used to another application for surround or
> > mic for karaoke
>
> I am not entirely convinced that this is really a common case.
>
> But anyway, there is nothing in PA that would limit it to not use
> multiple parallel devices of a sound card at the same time, with the
> exception that ALSA currently has no enumeration API which could
> inform us which uses of the card are exclusive each other and which
> ones are not. PA currently tries to open the sound card in all
> combinations possible, assuming that EBUSY means it found an invalid
> combination.


if  ( snd_pcm_info_get_subdevices_count(pcm_info) > 1 ) mean you can open
the device more than one time since the device has more than 1 subdevice