[Alsa-user] dmix, unable to open slave

[oxi <ox...@gm...>]

Hi,

I've been trying to set up alsa with dmix to play several streams at once s=
o I=20
don't have to close a sound application when I want to use another, f.e.

The problem is I get a dmix error all the time. I've been searching the als=
a=20
wiki and found a page where it's said that if you're getting this error and=
=20
have dmix set up good, that means some application is locking the /dev/dsp=
=20
device ( http://alsa.opensrc.org/FAQ056 ) . The problem is I couldn't manag=
e=20
to find out what this application could be, neither am I sure whether the d=
sp=20
is actually being used; but my guess is a no.

Below are some specifications and logs. Please don't hesitate to ask me for=
=20
any more information. Any light sed on this appreciated. Thanks in advance.

Regards,
oxi

=2D--

* Using Gentoo Linux

oxibox oxi # uname -a
Linux oxibox 2.6.19-gentoo-r5 #1 SMP Wed Jan 31 05:56:08 CET 2007 i686 AMD=
=20
Athlon(tm) 64 Processor 3200+ AuthenticAMD GNU/Linux

* Neither oss or alsa are compiled into the kernel.

Alsa packages versions:
media-libs/alsa-lib-1.0.14_rc1
media-libs/alsa-oss-1.0.12
media-sound/alsa-driver-1.0.14_rc1
media-sound/alsa-firmware-1.0.14_rc1
media-sound/alsa-headers-1.0.14_rc1
media-sound/alsa-tools-1.0.14_rc1
media-sound/alsa-utils-1.0.14_rc1

* Got an Echo Audio Layla24 sound interface as my primary device

=2D--

THIS IS MY /etc/asound.conf

# ~/.asoundrc

pcm.layla24 {
    type dmix
    ipc_key 1024
    slave {
        pcm "hw:0"
        period_time 0
        period_size 1024
        buffer_size 4096
        rate 44100
	channels 8
    }

    bindings {
        0 0
        1 1
	2 2
	3 3
	4 4
	5 5
	6 6
	7 7
        }
}

pcm.!default {
    type plug
    slave.pcm "layla24"
}

pcm.default {
    type plug
    slave.pcm "layla24"
}

#OSS
pcm.dsp {
    type plug
    slave.pcm "layla24"
}

pcm.dsp0 {
    type plug
    slave.pcm "layla24"
}

ctl.layla24 {
    type hw
    card 0
}

#JACK
pcm.jackplug {
    type plug
    slave.pcm "jack"
}

pcm.jack {
    type jack
    playback_ports {
        0 alsa_pcm:playback_1
        1 alsa_pcm:playback_2
    }
    capture_ports {
        0 alsa_pcm:capture_1
        1 alsa_pcm:capture_2
    }
}

#JUEGOS DE CANALES
pcm.uno {
        type plug
        slave.pcm "layla24"
        slave.channels 8
        ttable.0.0 1
        ttable.1.1 1
}

pcm.dos {
	type plug
	slave.pcm "layla24"
	slave.channels 8
	ttable.0.2 1
	ttable.1.3 1
}

pcm.tres {
        type plug
        slave.pcm "layla24"
        slave.channels 8
        ttable.0.4 1
        ttable.1.5 1
}

pcm.cuatro {
        type plug
        slave.pcm "layla24"
        slave.channels 8
        ttable.0.6 1
        ttable.1.7 1
}

=2D--

TESTING DMIX

oxibox oxi # /etc/init.d/alsasound restart
 * Storing ALSA Mixer Levels ...                [ ok ]
 * Unloading ALSA ...                           [ ok ]
 * Unloading ALSA modules ...                   [ ok ]
 * Loading ALSA modules ...
 *   Loading: snd-card-0 ...                    [ ok ]
 *   Loading: snd-card-1 ...                    [ ok ]
 *   Loading: snd-seq-oss ...                   [ ok ]
 *   Loading: snd-pcm-oss ...                   [ ok ]
 *   Loading: snd-seq-midi ...                  [ ok ]
 * Restoring Mixer Levels ...                   [ ok ]
oxibox oxi # lsof /dev/dsp
oxibox oxi # lsof | grep dsp
oxibox oxi # LC_ALL=3D"C" aplay -D plug:dmix tm-2007-03-20T03\:32\:51.wav &
[1] 10287
oxibox oxi # Playing WAVE 'tm-2007-03-20T03:32:51.wav' : Signed 16 bit Litt=
le=20
Endian, Rate 44100 Hz, Stereo

oxibox oxi # LC_ALL=3D"C" aplay -D plug:dmix tm-2007-03-20T03\:32\:51.wav &
[2] 10288
oxibox oxi # ALSA lib pcm_dmix.c:914:(snd_pcm_dmix_open) unable to open sla=
ve
aplay: main:545: audio open error: Invalid argument

[2]+  Exit 1                  LC_ALL=3D"C" aplay -D plug:dmix=20
tm-2007-03-20T03\:32\:51.wav