Hi,

I mean example code of a driver which works either on PCM and MP3 (or other compressed) audio stream.

Reagrds

David On Mon, Mar 15, 2010 at 2:14 PM, Mark Brown < broonie@opensource.wolfsonmicro.com> wrote:

On Mon, Mar 15, 2010 at 02:02:39PM +0000, Dajun Chen wrote:

...

I am wondering where to find the guidances of developing a device driver

for

...

a codec device which has a built-in DSP for MP3 (and tracks in other

format)

...

playback and recording?

OOI which device?

I'm not sure what you mean by guidance here. The standard thing would be to do it as a regular CODEC driver with a custom interface for userspace (eg, gstreamer) to talk to. The best way of handling DAPM will depend on implementation but probably representing the output of the DSP as an input pin will be easiest.

Thanks.

Please would you point me the place to see the TI and Intel drivers?

Regards

David

On Mon, Mar 15, 2010 at 4:15 PM, Mark Brown < broonie@opensource.wolfsonmicro.com> wrote:

On Mon, Mar 15, 2010 at 04:01:34PM +0000, Dajun Chen wrote:

Please don't top post, lack of context makes it difficult to follow the thread of discussion.

...

I mean example code of a driver which works either on PCM and MP3 (or

other

...

compressed) audio stream.

ALSA only handles PCM streams itself, compressed audio needs to be handled separately. The TI DSP stuff is one example of handling compressed audio, or the Intel Moorestown drivers, but since there's no standard for that stuff at the kernel level there's not much to look at.