[alsa-devel] ALSA mixer query

Clemens Ladisch clemens at ladisch.de
Fri Jan 28 14:00:23 CET 2011

Irfan Shaikh wrote:
> I am rendering audio to a PCM playback device (hw:0,0). I also need
> to render the same audio data to second PCM playback device (hw:0,1).
> 1) Can i use ALSA mixer APIs so that i give PCM audio data to 1
>    playback device or some common interface, but the PCM audio data
>    is rendered to both devices (hw:0,0 and hw:0,1)

The mixer API ist just an interface to the hardware, so this would
depend on the hardware's capabilities.

However, you could use the plugin mechanism to create a virtual PCM
device that routes its data to two actual devices.  See

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