[linux-audio-user] How to setup dmix with m-audio audiophile usb

[Florian Ladstaedter]

Hi,

I am struggling with setting up the alsa dmixer with the M-Audio 
Audiophile USB sound card. The card works well (even better now since 
alsa 1.0.11rc4/linux 2.6.17rc1) but only one application can access it 
at the same time. Internet search gives a lots of results for 
asound.conf dmix configurations (and that it should work out of the box 
with recent alsa versions) but the M-Audio seems to be special, as 
always. So,

1. Is this a stupid question? (I am a newbie...)

2. What's the correct asound.conf? I tried the following (and many 
similar to this):

[First soundcard is the onboard snd-intel8x0 card, the m-audio is the 
hw:2,0. It's a debian sid system with kernel 2.6.17rc2]


--------------------------------------
pcm.!default {
         type plug
         slave.pcm "dmixer"
}

pcm.dmixer {
         type dmix
         ipc_key 1024 # This must be a unique IPC key (see ipcs output)
         ipc_key_add_uid 0
         ipc_perm 0660
         slave {
                 pcm "hw:2,0"
                 channels   2;
                 period_time 4096
                 period_size 4096 # Must be power of 2 for alsa-oss
                 buffer_size 8192 # ditto
                 buffer_time   340000;
                 rate 44100
         }
         bindings {
                 0 0
                 1 1
         }
}

# OSS via aoss should d(mix)stroyed:
pcm.dsp2 {
type plug
slave.pcm "dmixer"
}

ctl.mixer2 {
     type hw
     card 2
}
-----------------------------------------

the card still works with this, but no sound mixing. Playing a song and 
using another sound appl at the same time gives:

WARNING **: alsa_setup(): Failed to open pcm device (hw:2,0): Device or 
resource busy


3. Can jackd and simple alsa apps use the soundcard at the same time 
with dmix (theoretically, if it would work)?

thanks, any help appreciated

Florian