Scratching sound recurrent every 5 to 20 seconds on karmic amd64 (not jaunty)

[Valombre]

Binary package hint: pulseaudio

Every 5 to 20 seconds i have a scratch sound very annoying, like a switch we put on and off ... even if i'm doing nothing.
I have this problem since Karmic alpha 6, not in jaunty where sound is correct.

If i use the sound gui and select sound off i still have the scratch effect, and i have no way (with gui) to select other manager (like alsa) than pulseaudio to test.

For info in live-cd and at first boot after install sound is very loud, i have to put it at 20/30 % maximum (no pcm parameter in the new sound gui).

I won't use karmic with such a bug it drives me crazy ... i keep going on jaunty waiting for a solution.

Apport bug attached ...

ProblemType: Bug
Architecture: amd64
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: CONEXANT Analog [CONEXANT Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: valombre 1625 F.... pulseaudio
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xf4600000 irq 22'
   Mixer name : 'Conexant CX20549 (Venice)'
   Components : 'HDA:14f15045,1631c20e,00100100'
   Controls : 18
   Simple ctrls : 8
Date: Wed Oct 28 11:17:39 2009
DistroRelease: Ubuntu 9.10
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
NonfreeKernelModules: nvidia
Package: pulseaudio 1:0.9.19-0ubuntu4
ProcEnviron:
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-14.48-generic
SourcePackage: pulseaudio
Uname: Linux 2.6.31-14-generic x86_64
XsessionErrors:
 (gnome-settings-daemon:1684): GLib-CRITICAL **: g_propagate_error: assertion `src != NULL' failed
 (gnome-settings-daemon:1684): GLib-CRITICAL **: g_propagate_error: assertion `src != NULL' failed
 (nautilus:1785): Eel-CRITICAL **: eel_preferences_get_boolean: assertion `preferences_is_initialized ()' failed
 (polkit-gnome-authentication-agent-1:1791): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed

[Luke Yelavich (themuso)]

WHat is the CPU usage when you play audio in karmic? The easiest way to find this out is to run gnome-system-monitor.

Secondly, have you tried disabling pulseaudio's glitch free function? To do this, edit /etc/pulse/default.pa, and find this line:

load-module module-udev-detect

Then add "tsched=0" to the end of it, log out, and log back in.

Finally, were you attempting to play audio when running the live CD, or when karmic was installed?

Thanks for any information you can provide.

 affects ubuntu/pulseaudio
 status incomplete

[Valombre (valombre-d)]

The cpu usage with rythmbox (playing inthecircle.oga) and gnome-system-monitor is arround 15-20 % for the 2 cpu (intel core2 duo T7500)

While playing sound no more glitch/scratch.
After playing sound the glitch was less frequent around 1 minute then 5 seconds, after a while of inactivity again 5 to 20 seconds.

A vim of /etc/pulse/default.pa adding tsched=0 line 54 =>
### Automatically load driver modules depending on the hardware available
.ifexists module-udev-detect.so
load-module module-udev-detect tsched=0
.else

Logout/login same problem the glitch sound every 5 to 20 seconds, for info the 2 sounds are a little different like a switch we put on then off.

I didn't try to run a CD audio just testing the basic live-cd and install as i'm an iso installer tester (Valombre) => http://iso.qa.ubuntu.com/qatracker/result/3379/8

If more tests needed just tell ;)

[Valombre (valombre-d)]

Today 31/10 i booted karmic to check for updates, the glitches where less frequent ... but first time i played a sound the glitches came back, i applied updates same thing and glitches are less frequent but still there.

[Valombre (valombre-d)]

Well, i found a way to deactivate the glitch, it comes apparently from the "Monitor of Audio interne Analog Stereo" witch is not available from the standard interface, i have to install it => asoundconf-gtk

And after deactivate it from the interface no more glitch in session, when i reboot i have 2 or 3 glitches until the desktop is fully loaded, and no more after.

For info i migrate my second laptop (office) Thinkpad R61, from 9.04 to 9.10 and surprise i add the same glitch problem => 00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 03)

I solve the problem doing the same.

I guess i'm not the only one to encounter this, but as the deactivation of the "Monitor of Audio interne Analog Stereo" is not possible with standard gui i still think it's a real bug.

I post attachment of screen-shoot with/and without the "Monitor" activate:

[Valombre (valombre-d)]

Finally glitch is back, just 2 times after going out of standard screensave mode, and this on my 2 laptops.

[Valombre (valombre-d)]

Still glitch/scratch .. the only way to avoid it is to use an application which leave an audio stream open, i use audacious with the the crossfade plugin activate and the advanced option "keep output opened" ... ugly solution but i have no other solution actually.

I wait for the next update ..

[Valombre (valombre-d)]

Finally a solution to my problem found in another bug => https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/452343
No more glitch after applying the power_save to 0 in /etc/modprobe.d/alsa-base.conf
I hope this tweak will be integrated in next updates.