[BUG] Frequent distortion in sound output

[fictive]

Distribution: Archlinux 64bit
Motherboard: ASUS P8P67-Pro
Using external (PCI-attached) audio card (SB Live 5.1), because no drivers exist for the motherboard's built-it sound card.

• The distortion can be clearly heard from the speakers. Front and rear channels exhibit the same symptom.
• It is only audible during playback
• It occurs randomly but very often and is audible until audio is stopped.
• Workaround so far has been to stop and start the software playing the audio a few times.
• Restarting OSS itself doesn't make any difference.
• Nibbling with audio settings doesn't make any difference.

[cesium]

What happens if you disable vmix? ('vmix_disabled=1' in /usr/lib/oss/osscore.conf, or maybe just set vmix0-enable to OFF in the mixer). Btw, what's wrong with the internal audio?

[fictive]

What happens if you disable vmix? ('vmix_disabled=1' in /usr/lib/oss/osscore.conf, or maybe just set vmix0-enable to OFF in the mixer).

Disabling the vmix in the config file makes the distortion go away, but audio can only be played in one application at a time after that change. Oddly, disabling the vmix on the mixer does nothing.

Edit /usr/lib/oss/build/osscore.c and change line 811 to have a '<=' memlimit comparison. Run 'sudo sh install.sh' in the same directory and restart OSS. I don't think it would help here, but I recall it did help someone with a similar issue (which had audigy).

Relinking succeeded and OSS restarted, but the distortions are still present.

Btw, what's wrong with the internal audio?

Internal audio card just doesn't show up on the ossxmix. It is "Realtek® ALC892 8-Channel Audio CODEC", currently turned OFF from bios.

[cesium]

Hmm... You can try attaching it manually (disable it and then 'sudo vmixctl attach -M /dev/dsp /dev/dsp_in') and see if that helps. And idea: rebuild OSS from source, providing --config-vmix=FIXEDPOINT argument to configure and test with that.

[fictive]

Hmm... You can try attaching it manually (disable it and then 'sudo vmixctl attach -M /dev/dsp /dev/dsp_in') and see if that helps.

VMIX disabled in osscore.conf. vmixctl with the parameters you gave outputs "/dev/dsp: Device or resource busy"

And idea: rebuild OSS from source, providing --config-vmix=FIXEDPOINT argument to configure and test with that.

No noticeable change. Distortions still occur.

[cesium]

The /dev/dsp message is because something is using the card. You can check this via "fuser /dev/dsp". Kill it, and try vmixctl again.

[fictive]

The /dev/dsp message is because something is using the card. You can check this via "fuser /dev/dsp". Kill it, and try vmixctl again.

Already checked. The device node is not open by any program and no program has oss libraries loaded.

Code: Select all

$ fuser /dev/dsp
$ fuser /dev/dsp_in
$ lsof -n | grep -i oss
$ lsmod | head -n 3
Module                  Size  Used by
oss_sblive             87994  0
osscore               551852  1 oss_sblive


lsmod also shows that 'osscore' is used only by 'oss_sbline' and 'oss_sblive' is not used by anyone.

[cesium]

Hmm.. Try 'sudo vmixctl attach -r -M /dev/oss/oss_sblive0/pcm0'

[fictive]

Code: Select all

$ vmixctl attach -r -M /dev/oss/oss_sblive0/pcm0
VMIXCTL_ATTACH: Input/output error


The device referenced exists and is not a symlink.
*Sigh*

[cesium]

You need root privileges for this, which is why I placed 'sudo'... (The '$' prompt suggest you're doing this as a normal user)

[fictive]

Yes, it was run as root (su -). I have tweaked my PS1 environment variable.

[cesium]

Hmm.. are you sure you disabled vmix before this? You can check this in 'ossinfo -v2' printout...

[fictive]

Hmm.. are you sure you disabled vmix before this? You can check this in 'ossinfo -v2' printout...

Code: Select all

$ grep -i vmix_disabled /usr/lib/oss/conf/osscore.conf
vmix_disabled=1

Code: Select all

$ ossinfo -v2

Output can be found in the attachment. Only one application can output sound at once but seems the 'Related mixer dev' references 'Mixer device 0'. I haven't a clue how to verify that my mixer is disabled.

Disabling the vmix in the config file makes the distortion go away, but audio can only be played in one application at a time after that change. Oddly, disabling the vmix on the mixer does nothing.

At first I thought the distortions went away. Now that I have used my computer for quite some time with "vmix_disabled=1", I have witnessed the distortions a few times. They still exists :(

[fictive]

Thanks for the help. Problem fixed. I bought a new sound card.