Patch to alsa-plugins causes regression in java applet (webex)

We can't simply revert the patch as that would cause issues in other applications. I think we need to extend PulseAudio's protocol to include information about when the underrun happened in order to determine whether the underrun should be ignored or not.

OK, will you work on a patch that helps this with upstream?

Hi David, I see bug #503174 has a fix for underruns too, I'm going to test this with webex.

Fix from #503174 had no affect. Reverting lp464008lp503174.patch still works.

Thanks David, do you have any packages with these patches so I can test them on the Latitude 2120?
I can knock one together if the answer is no :)

Well, the PulseAudio patch is included in the next version of PulseAudio, which we are currently considering for Oneiric (see https://lists.launchpad.net/ubuntu-audio-dev/msg00212.html ), and the alsa-plugins patch is broken, but I'll attach a fixed version now. Note that the alsa-plugins patch would need the new PulseAudio to compile.

Since Oneiric is a good 2 months away, is there any chance of the "fixed" alsa-plugins being backported to Natty?

@Slava, given the changes to the PulseAudio protocol that are preconditions to this additional protocol update, backporting this into Natty seems highly unlikely. Sorry.

This bug was fixed in the package alsa-plugins - 1.0.24-0ubuntu6

---------------
alsa-plugins (1.0.24-0ubuntu6) oneiric; urgency=low

  * Use the new PulseAudio API for better underrun handling (LP: #805940)
 -- David Henningsson <email address hidden> Wed, 24 Aug 2011 10:16:12 +0200

is there anything that can be done to sort this for lucid? other than using a custom package?

@Tellis: Doing an SRU to change the behavior is not an option because that will regress other applications, and the better solution released in Oneiric requires the new PulseAudio API (which is not backportable to Lucid).

However, there might actually be ways to configure this behavior, but I don't know if such a configuration change would be easier to roll out than a custom package. I'm lacking knowledge of what is possible and not possible in your environment, so it's hard for me to know what to suggest.

So...maybe fixing webex not to abuse the API? :-)

Thanks David, I don't think getting webex to change anything is possible.

It seems to me like the best approach is to run the slightly modified alsa-plugin package with the one patched removed and lock the package.

It seems this bug also causes problems with WINE Windows compatibility layer, see http://wiki.winehq.org/Sound

This problem is still seen in 32-bit Precise. I've captured a log of pulseaudio of the failure. We are getting the same buffer Underrun.
I'm able to reproduce using webex using sun java 1.6.

Unfortunately I still have this bug in 64 bit Precise.

I confirm the instance of the bug under Ubuntu 12.04, wine 1.4.1
Using Civilization 4, Rise of Mankind - A New Dawn Mod

Sound will just drop out, or will play a 2x speed occasionally.

Most of play it remains fine, but will happen eventually.

*Edit* Ubuntu 12.04 64 bit
Wine 1.4.1
Civilization IV, Beyond the Sword, Rise of Mankind - A New Dawn mod

I've done some additional testing recently using the above setup, and three versions of Ubuntu with and without Pulseaudio.

Java Version

Oracle JRE 7 (1.7.0_05) PulseAudio Enabled 12.04 i386 Fail [1]: 2
Oracle JRE 7 (1.7.0_05) PulseAudio Disabled 12.04 i386 Works: 6

Sun JRE (1.6.0_31) PulseAudio Enabled 11.10 i386 Works: 3
Sun JRE (1.6.0_31) PulseAudio Disabled 11.10 i386 Works: 2
Oracle JRE 7 (1.7.0_05) PulseAudio Enabled 11.10 i386 Works: 2
Oracle JRE 7 (1.7.0_05) PulseAudio Disabled 11.10 i386 Works:1

Sun JRE (1.6.0_31) PulseAudio Enabled 10.04 i386 Fail [1]: 1
Sun JRE (1.6.0_31) PulseAudio Disabled 10.04 i386 Works: 1

I hit the return key before completing my last comment accidentally.

The table shows the java version, if pulse audio is enabled, which version of Ubuntu, and if it failed or worked.
In summary, if pulse audio is disabled it works in all versions of Ubuntu (Lucid, Oneiric, Precise)
If Pulse audio is enabled, it only works in Oneiric and not in Precise nor Lucid.

Status changed to 'Confirmed' because the bug affects multiple users.

After many tests, the problem was solved by editing /etc/pulse/default.pa and replacing string:
load-module module-udev-detect
by
load-module module-udev-detect tsched=0

seurce: https://wiki.archlinux.org/index.php/PulseAudio#Glitches.2C_skips_or_crackling

oneiric has seen the end of its life and is no longer receiving any updates. Marking the oneiric task for this ticket as "Won't Fix".

lucid has seen the end of its life and is no longer receiving any updates. Marking the lucid task for this ticket as "Won't Fix".

The Precise Pangolin has reached end of life, so this bug will not be fixed for that release