[alsa-devel] Custom Kernel driver to open and use another ALSA PCM

[ed nwave]

Hello,

A little bit of an unorthodox request but I need my custom PCM driver to
connect directly to another PCM driver if possible. I have an application
that already sees my custom PCM driver as the connected sound card, but I
also need to pipe the PCM data within my driver after altering it out to
another PCM of my choice ( my actual sound card ).

As an example, my PCM driver acts as a sound card connected to a microphone
capture application, within the my custom PCM I've added various "dalek"
and other voice changing alterations and now I need to output this stream
into my actual sound card.
The sound card I need my driver to import or connect to is a DAC over USB
and I believe the loaded kernel module is snd_sub_audio which I can see via
lsmod. It's PCM hw:1,0.

So is this possible? An if so, how? Even the most basic information would
be appreciated.

Thanks.