2010/8/31 Stephen Warren <swarren@xxxxxxxxxx>
> Takashi Iwai wrote:
> >
>
> > > Unfortunately, it doesn't look like it's possible for applications to
> query
> > > this information from ALSA, since a hw_params_t exposes just a min/max
> > > channel count rather than a mask.
> >
> > It can be also masked.
>
> Are you saying the APIs already support a mask for channel count, and I
> just
> didn't find it, or that the APIUs should be updated to report a mask?
>
> Thanks.
>
> you can find the examples in intel8x0.c
static unsigned int channels2and8[] = {
2, 8,
};
static struct snd_pcm_hw_constraint_list hw_constraints_channels2and8 = {
.count = ARRAY_SIZE(channels2and8),
.list = channels8,
.mask = 0,
};
runtime->hw.channels_max = 8;
snd_pcm_hw_constraint_list(runtime, 0,
SNDRV_PCM_HW_PARAM_CHANNELS,
&hw_constraints_channels2and8);
The ALSA application need to snd_pcm_hw_params_test_channels() to find the
supported channel one by one
_______________________________________________
Alsa-devel mailing list
Alsa-devel@xxxxxxxxxxxxxxxx
http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
