[alsa-devel] Compressed Audio Playback/Capture through ALSA framework

Koul, Vinod vinod.koul at intel.com
Thu Mar 17 03:21:40 CET 2011

On Wed, 2011-03-16 at 23:38 +0530, Mark Brown wrote:
> On Wed, Mar 16, 2011 at 01:00:09PM -0500, pl bossart wrote:
> > On Wed, Mar 16, 2011 at 12:53 PM, Mark Brown
> > > It'd make the tie up with algorithms part much easier as we could have
> > > an interface for transferring the compressed data alone and then
> > > externally describe how that's plumbed into any other DSP that's going
> > > on and the physical outputs - it'd help with treating the data transfer
> > > as a standalone problem.
> > Still not convinced. Why would you need to 'externally describe' how
> > compressed data is linked to post-processing. It's all part of DSP
> > firmware, why should anyone care how the decoder provides data to
> > post-processes? You can control post-processes with ALSA controls as
> > for regular PCM.
> The problem is figuring out which controls are where and what can be
> joined up with what.  This is a problem with regular PCM too but it gets
> much worse when everything is virtual.  Media controller should provide
> a route to allowing applications to figure out what's going on in the
> hardware.
Wouldn't a virtual sound card solve this? I was thinking of representing
all DSP elements in a virtual card. From userland, we know when decoder,
algorithms etc are active and can control them.
The virtual card output gets connected to actual sound card.


More information about the Alsa-devel mailing list