Re: [Alsa-user] Two sound cards simultaneously

[Mark C. <ma...@re...>]

On 2007-09-27 20:58, Jonathan Stowe wrote:
> > Its beyond me too thats why I ask here;)
> > If here nobody understands this magic where I can ask for it?;)
> 
> See http://alsa.opensrc.org/index.php/TwoCardsAsOne

I've also read all of this below, a couple of times over
the years, but it still make almost zero sense to me.

 http://alsa-project.org/alsa-doc/alsa-lib/pcm_plugins.html

I've spend over an hour trying various combinations but I
have no idea how to coordinate the zillion alsa-lib options
to reach a particular end goal.

As a baseline, say I started with this, where could I go
from here to get an app (ie; Amarok) to play back out two
soundcards at once ?

# cat .asoundrc
pcm.NVidia { type hw; card NVidia; }
ctl.NVidia { type hw; card NVidia; }

pcm.USX2Y  { type hw; card USX2Y; }
ctl.USX2Y  { type hw; card USX2Y; }

pcm.shared {
  type dshare
  ipc_key 321456  # any unique value
  ipc_key_add_uid true
  slave NVidia
  slave USX2Y
  bindings {
    0 0
    1 1
  }
}

--markc