[alsa-devel] Does ASoC support sound card with multiple interfaces?

Rajeev kumar rajeev-dlh.kumar at st.com
Wed Jan 4 06:47:55 CET 2012

Hello Ashish

On 1/4/2012 11:06 AM, Ashish Chavan wrote:
>>>    I have a codec with multiple TX and RX channels. In ASoC tree, I have
>>> seen examples where these kind of codecs are implemented as multichannel
>>> codecs. Instead I want it to be treated as card with multiple
>> Yes, this is totally supported.  There are quite a few examples of this
>> in the tree.  Your CODEC driver should just implement one DAI per audio
>> interface.
> Thanks.
> I am looking at some of the examples in the tree and have a small query.
> I want to know how alsa-utils (aplay, arecord) will behave when a codec
> driver supports multiple DAIs. For example, let's assume that a codec
> driver implements two DAIs, both capable of doing stereo playback. Then
> I try to play two files simultaneously using aplay, e.g.
> $ aplay x.wav
> $ aplay y.wav
> AFAIK first "aplay" will result in play back on default interface/DAI
> (i.e. 0). What will happen with second aplay? Will it automatically find
> a free DAI to playback?


  or it is mandatory to explicitly specify the
> PCM/card # for second aplay?

You need to redirect it . You can use

aplay -Dplughw:0,1 x.wav.

Here '0' indicated card number and '1' indicates device number


> Similarly what will happen in case of arecord when a codec supports
> multiple DAIs capable of capturing?
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel at alsa-project.org
> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel

More information about the Alsa-devel mailing list