Doom 3 sound distortion: Mandriva 2005 LE, via82xx

[Guest FunkyMunky]

Hi,

 

I've just installed the latest Doom 3 native port and I'm getting weird distortions when I use ALSA as the sound back-end. The game sounds "digitally" distorted, as if the sound was passing through some sort of filter. It doesn't crackle like it would if I had the PCM level too high, and when I use the OSS backend (ALSA emulated, ironically), it sounds ok...except there's no surround output so the game sounds pretty bassless. I've attached an ogg of what the distortion sounds like, you can hear midway through the recording I change back to OSS mode (and you can make out the sounds as they should be) then flick back to ALSA.

This problem isn't affecting any of my other ALSA applications. I've installed the OpenSound drivers to try get surround working in Doom 3 using OSS but that hasn't worked, so I'm wondering if there are any solutions to the ALSA distortion.

 

Alsa 1.0.8 on Mandriva 2005, via82xx drivers (Realtec ALC850 audio)

Thanks

David

dodgy_doom.ogg.tar.gz

[devries]

Perhaps the sampling rate? What does your asoundrc look like? Try 48000 or 44100.

[Guest FunkyMunky]

Hi,

 

my .asoundrc is pretty bland, all I have is a tweak to upmix stereo sound ie

 

pcm.ch51dup {
type route
slave {
pcm "surround51"
channels 6
}
ttable {
0.0 1 # put left front in left front
1.1 1 # put right front in right front
0.2 1 # put left front in left rear
1.3 1 # put right front in right rear
0.4 0.5 # put 50% of left front in center
1.4 0.5 # put 50% of right front in center
0.5 0.5 # put 50% of left front in sub
1.5 0.5 # put 50% of right front in sub
}
}

 

I'll remove that and see what effect it has...how would I go about changing the sampling rate? I've the only "option" as such I can find is in the KDE sound system control, and I'm not sure how I would change that within Doom or the .asoundrc

 

Thanks

 

EDIT: I've removed that from my .asoundrc and I still have the problems. I'll have a look and see if there's a switch to change the sampling rate doom uses.

[Guest FunkyMunky]

I've just tried starting the game from a console rather than by the icon, and I see errors about sound frames overflowing and being dropped...perhaps something to do with the buffer size?

 

--------------------------------------
dlopen(libasound.so.2)
asoundlib version: 1.0.8
Alsa is available
------ Alsa Sound Initialization -----
opened Alsa PCM device default for playback
device buffer size: 5461 frames ( 65532 bytes )
allocated a mix buffer of 49152 bytes
--------------------------------------
--- Common Initialization Complete ---
terminal support enabled ( use +set in_tty 0 to disabled )
pid: 15743
1008 MB System Memory
128 MB Video Memory
Async thread started
snd_pcm_writei short write: 4085 out of 4096
snd_pcm_writei short write: 2021 out of 2048
snd_pcm_writei short write: 989 out of 1024
snd_pcm_writei short write: 989 out of 1024
idAudioHardwareALSA::Write: 4096 frames overflowed and dropped
snd_pcm_writei short write: 989 out of 1024
snd_pcm_writei short write: 989 out of 1024
snd_pcm_writei short write: 989 out of 1024
snd_pcm_writei short write: 989 out of 1024
idAudioHardwareALSA::Write: 4096 frames overflowed and dropped

[devries]

There is some information here: http://radagast.bglug.ca/epia/epia_howto/x331.html Try the asoundrc mentioned there:

pcm.via82xx {

  type plug

  slave {

    pcm "hw:0,0"

    rate 48000

  }

}

ctl.via82xx {

  type hw

  card 0

}

 

And the gentoo wki has one: http://gentoo-wiki.com/HOWTO_ALSA_sound_mixer_aka_dmix

 

Good luck

[Guest FunkyMunky]

I have to admit I'm completely lost now. I've tried the addition to .asoundrc you suggested above, but nothing happened. I've found the Doom 3 ouputs only 44100Hz so I changed the value you suggested from 48000 to 44100 but still no luck. The OSS support in Doom seems to have stopped now as well but that's not too much of a problem...I'm still stumped by this ALSA thing.

[Guest LoneWolf]

Had the same problem with FC3 and VIA integrated VT82xx sound card. I added the following to my .asoundrc file. And switched Doom3 to using OSS.

 

# ~/.asoundrc

 

# our ICE1712 dmix:

pcm.ossmix {

type dmix

ipc_key 1024

slave {

pcm "hw:0,0"

period_time 0

period_size 1024

buffer_size 4096 # buffer size < 6653, but pow(x, 2)

rate 48000 # we want to play CDs only

}

 

bindings {

0 0

1 1

}

}

 

# Everything shall be dmixed, so redefine "default":

pcm.!default {

type plug

slave.pcm "ossmix"

}

 

# OSS via aoss should d(mix)stroyed:

pcm.dsp0 {

type plug

slave.pcm "ossmix"

}

 

ctl.mixer0 {

type hw

card 0

}

 

Basically, this is a sound card driver issue. Since a lot of other Doom3 users. Are not apparently having this problem.