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

[Ashish Chavan]

> You need to redirect it . You can use
> 
> aplay -Dplughw:0,1 x.wav.
> 
> Here '0' indicated card number and '1' indicates device number

Is it really mandatory to specify card and device id? Isn't there a
middle layer that takes care of using "first free" interface for
playback or recording, if interface is not explicitly specified? As we
register DAIs with ALSA subsystem, it should be fairly easy for alsa-lib
to find out "first free" interface.

I am aware that this wouldn't be practically useful in most cases,
because generally we know beforehand which specific interface to be used
for playback/recording. In such cases, automatic selection of interface
may be confusing to users. But I just want to confirm if this is at all
possible?