Permission to use alsa dmix

Ian_Hawdon · 12-20-2005, 08:05 AM

Hi,

Alsa is not playing by the rules

i am trying to get my nforce 3 (on my laptop) to run full duplex:

here is my asound.conf file:

Code:

pcm.intel8x0 {
  type hw
  card 0
  device 0
}

pcm.dmixer {
  type dmix
  ipc_key 1111
  slave {
    pcm intel8x0
  }
}

pcm.!default {
  type plug
  slave {
    pcm dmixer
    format S16_LE

  }
}

pcm.dsp {
    type plug
    slave.pcm "dmixer"
}

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

and here is the status of my /dev/dsp:

Code:

ian@linux:/etc> ls -la /dev/dsp
crw-rw----+ 1 root audio 14, 3 2005-12-20 13:47 /dev/dsp

and my /dev/snd:

Code:

ian@linux:/etc> ls -la /dev/snd
total 0
drwxr-xr-x   2 root root      180 2005-12-20 13:47 .
drwxr-xr-x  11 root root    15540 2005-12-20 13:47 ..
crw-rw----+  1 ian  audio 116,  0 2005-12-20 13:47 controlC0
crw-rw----+  1 ian  audio 116, 24 2005-12-20 13:47 pcmC0D0c
crw-rw----+  1 ian  audio 116, 16 2005-12-20 13:47 pcmC0D0p
crw-rw----+  1 ian  audio 116, 25 2005-12-20 13:47 pcmC0D1c
crw-rw----+  1 ian  audio 116, 18 2005-12-20 13:47 pcmC0D2p
crw-rw----+  1 root audio 116,  1 2005-12-20 13:47 seq
crw-rw----+  1 ian  audio 116, 33 2005-12-20 13:47 timer

when i am using a music aplication and i run another program that uses sound, it just dosnt work :'(

when i am using amaroK and then run asound in the console i get this:

Code:

ian@linux:/etc> aplay
ALSA lib pcm_dmix.c:818:(snd_pcm_dmix_open) unable to open slave
aplay: main:540: audio open error: Permission denied

what is going on?

Ian_Hawdon · 12-20-2005, 11:15 AM

bump... please help

madluther · 12-20-2005, 11:39 AM

Code:

crw-rw----+ 1 root audio 14, 3 2005-12-20 13:47 /dev/dsp

/dev/dsp permissions allow user root and members of the group audio write access, ensure your login is a member of the audio group and it should work.

Ian_Hawdon · 12-20-2005, 11:48 AM

how do you add a user to the audio group? i know

question, but i have never needed to do that!

Ian_Hawdon · 12-20-2005, 11:52 AM

ok forget that, here is what i have done:

Code:

linux:/home/ian # usermod ian -G audio
linux:/home/ian # aplay
ALSA lib pcm_dmix.c:818:(snd_pcm_dmix_open) unable to open slave
aplay: main:540: audio open error: Permission denied

as you see, it still doesnt work :'(

madluther · 12-20-2005, 11:56 AM

Code:

usermod -G audio ian

should add the user ian to the audio group.

Ian_Hawdon · 12-20-2005, 12:47 PM

still is not working

i have tried logging in as root and it works there so why not in my user?

edit ian_hawdon: fixed spelling

Ian_Hawdon · 12-20-2005, 02:32 PM

ok, i have found out this is only happening in skype hmm

liquidtenmilion · 12-20-2005, 02:37 PM

DMIXing only works in Alsa applications. If you run just ONE Oss app, it will block off the soundcard for every other app including Alsa apps.

Basically, you can run as many Alsa apps at one time as you want. But you can only run one and only one OSS app.(and if you run an oss app you can't run any alsa apps until you close the oss app)

Ian_Hawdon · 12-21-2005, 03:53 AM

is there anyway of making an oss aplication think it is an alsa aplication?

liquidtenmilion · 12-21-2005, 09:09 AM

Yes there is.

For some apps, you can run "aoss appname" if you have the alsa-oss program installed. It doesn't work with every program though.