[alsa-devel] Multiple channels mapping

[Takashi Iwai]

At Tue, 07 Feb 2012 17:02:00 -0800,
Patrick Lai wrote:
> 
> Hi,
> 
> The DSP I am working on supports channel assignments similar to ALSA
> route plug-in described in this link http://drona.csa.iisc.ernet.in
> /~uday/alsamch.shtml.
> I am currently looking a way to pass channel/speaker mapping
> information of PCM stream( i.c channel 0 -> Front Left speaker, channel
> 1 -> Front Right speaker) to ALSA driver. I looked at latest kernel
> tree and don't think there is already provision for my purpose. Can
> anyone confirm? If I were to improvise a way to pass channel/speaker
> mapping information, should I follow the same approach similar to how
> bits per sample and other hardware parameter is passed?

Currently the channel-mapping information is a missing piece in ALSA
framework, and it's a very long-standing item on my TODO list.

The implementation itself should be easy, but the only question is the
API design.  If you have a good proposal, please speak up.


thanks,

Takashi