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

[Koul, Vinod]

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.

-- 
~Vinod