[alsa-devel] PCM extra attributes

Jaroslav Kysela perex at perex.cz
Thu Jul 25 10:06:52 CEST 2013

Date 24.7.2013 19:09, Vinod Koul wrote:
> Hey Takashi,
> We were looking to find the substream index in the userspace for the device
> opened (in case we support multiple substreams and mix them). Since we also
> wanted to have some specific alsa controls for each substream the problem of not
> knowing substream in usermode make stuff interesting!

The substream/subdevice index is in the snd_pcm_info field, so you can
correlate the PCM with the controls from the control API.



Jaroslav Kysela <perex at perex.cz>
Linux Kernel Sound Maintainer
ALSA Project; Red Hat, Inc.

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