On Wed, Dec 23, 2009 at 10:14 PM, Brent Busby <brent(a)keycorner.org> wrote:
From what I've gathered online, I think what I
need may be a .asoundrc
file. Then again, maybe not: The asoundrc documentation says that what
it's doing is basically mapping device/channel names found in
/proc/asound/devices (sort of the same info you get from 'aplay -L') to
custom names and routings. Problem is, the 18 channels of the Multiface
all show up as *one* PCM device here! Where are all my subdevices? For
that matter, if I did even try to use that one PCM, which channel would
it come out of? (Haven't tried it...not really that curious.)
the RME hammerfall/hdsp and related devices have a single PCM
subdevice. you cannot access specific channels of that subdevice via a
device name unless you set up a "route" ALSA plugin pseudo-device
(google will reveal more). Even when you do, using that device will
"own" the entire PCM device - you can't have app A on channels 1 and 2
and app B on channels 3 and 4. My recollection is that if you use
plughw:N to access the device, and just send it 2 channels, they will
be replicated across all channels.
Other people have asked this before, but most such
threads seem to
always come to "just use Jack." Is it impossible to directly access
these devices from Alsa? I'm not wanting anything fancy here.
Actually, you might want something fancy. It sounds if you want
per-app access to specific channels. ALSA doesn't do that by itself.