Re: [Alsa-user] hda_intel with external DAC

[Lee R. <rlr...@jo...>]

On Wed, Feb 4, 2009 at 1:15 PM, Dirk Mast <con...@gm...> wrote:
> Until now I used the normal line-out, which was working fine and mixing was
> no problem.
>

HDA intel does not support hardware mixing, so your distro must be
using PulseAudio or dmix on the default device.

> Using the following .asoundrc
>
> pcm.hda-intel {
>      type hw
>      card 0
> }
>
> ctl.hda-intel {
>    type hw
>    card 0
> }
>
>
> I can listen to multiple streams (flash, amarok, xmms, whatever).
> But I'm wondering, if this alsa setup is resampling 44.1Khz to 48Khz.
>

This .asoundrc doesn't do anything, as apps will use the "default"
device, not "hda-intel".

Software mixing *requires* resampling all streams to a common sample
rate, 48Khz by default because not all sound cards support 44.1Khz.
You could configure pulseaudio/dmix/whatever to resample everything to
44.1Khz, but then 48Khz streams will be downsampled.

>
> When I use the following .asoundrc
> pcm.!default iec958:Intel
>
> The audio devices get's locked by a single application, which is not nice.
>

You need to configure your sound server to output to the iec958
device, as the hardware only supports one stereo stream.

> - no resampling in terms of 44.1 <-> 48
> BUT
> - decoding of those AC3/DTS streams
>

iec958 only supports 2 channels.  Either you set up xine to decode
those and downmix them to stereo, or you send the raw AC3/DTS stream
to the device and have your receiver decode it.

> How are my .asoundrc / xine / player configs expected to lookalike?

Depends on how your distro sets up the default ALSA device, sorry I
can't help more.  Does Debian testing use pulseaudio?

Lee