[AG-TECH] HD audio & USB audio on Linux?

[Piers O'Hanlon]

Hi Bob,

On Thu, Apr 17, 2008 at 3:15 AM, Robert Olson <olson at mcs.anl.gov> wrote:
>  The internal audio device handling code in rat is very different for OSS
> than it is for ALSA; the OSS one is probably much more mature. I'd hazard a
> guess that that is at least part of the explanation.
>
I spent a while looking into the problems with ALSA and contacted the
ALSA developers [Jaroslav Kysela] who said: "I judge from period_size
that we have another problem with rate plugin. It would be better to
do rate resampling in RAT." Basically RAT has been doing the right
thing but the ALSA rate_plugin (ALSA audio is constructed from a bunch
of ALSA plugins) goes into XRUN when it shouldn't.
http://mailman.alsa-project.org/pipermail/alsa-devel/2007-November/003944.html

Basically someone needs to fix the rate plugin and/or add resampling
into RAT at the audio input side - there is some resampling that RAT
does elsewhere.
(there is also a [GPL] resampling library - but GPL brings up
issues...). To be honest I had hoped that the ALSA stuff would
improve....

Piers.

> --bob
>
>
> On Apr 16, 2008, at 6:01 PM, Christoph Willing wrote:
>
>
> We've always found that, for some weird reason, RAT's audio quality is
> better when you select OSS - even though this is really just ALSA pretending
> to be OSS.
>