VLC sound light stuttering every few seconds (pulseaudio, alsa, oss) (video or music file)

[Mahendra Tallur]

Binary package hint: vlc

Since Ubuntu 9.10 (AMD64) (didn't happen in Jaunty), VLC (even the updated version that chooses Pulseaudio by default) produces some light sound "stuttering" every few seconds when playing a video or even just a music file.

It sounds a bit like what you hear when you have a corrupt file (but they aren't). It happens about every 5 seconds (and you can also hear in the first second of the file). Here it happens with ANY file (.avi, .mp3 .ogg...). It doesn't happen with any other audio player. I tried all possible modes (alsa, oss, pulseaudio) : they all lead to the same result.

I also tried the VLC PPA with a slightly newer (1.0.3) version : same result.

Sound is perfect in all other apps (except audacious2 that needs the alsa plugin to play properly, or the famous wine bug).
My audio device is the following :
00:1b.0 Audio device: Intel Corporation 82801JI (ICH10 Family) HD Audio Controller

vlc:
  Installé : 1.0.2-1ubuntu2
  Candidat : 1.0.2-1ubuntu2
 Table de version :
 *** 1.0.2-1ubuntu2 0
        500 http://fr.archive.ubuntu.com karmic/universe Packages
        100 /var/lib/dpkg/status

I don't report it upstream for the time being (tell me if it's necessary) because it seems distro related as it didn't happen in Jaunty.

ProblemType: Bug
Architecture: amd64
Date: Tue Nov 10 10:08:18 2009
DistroRelease: Ubuntu 9.10
ExecutablePath: /usr/bin/vlc
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
NonfreeKernelModules: nvidia
Package: vlc-nox 1.0.2-1ubuntu2
ProcEnviron:
 SHELL=/bin/bash
 LANG=fr_FR.UTF-8
ProcVersionSignature: Ubuntu 2.6.31-14.48-generic
SourcePackage: vlc
Uname: Linux 2.6.31-14-generic x86_64

[Mahendra Tallur (mahen)]

After further tests, it seems the issue only affects some audio codecs, but not all of them.

- mpga audio codec (movie) : issue
- mpga (standalone mp3) : issue
- a52 (movie) : no issue
- mp4a (movie) : no issue
- vorb (standalone ogg) : no issue

issue meaning : some gaps / stuttering every few seconds.

[Richard Clifford-Smith (richard-cs)]

I have this same problem, also on Ubuntu 9.10 amd64. This is version 1.02 from the repositories. For me it seems to be more like every 2 seconds but sometimes it's very noticeable and sometimes just very faint pops. Occasionally it won't happen but then it does when I try the same file again later or it'll just start as I'm listening to it.
Everything else as above, all other audio and video players are fine, and it happens whatever audio setting is used.

[Daniel T Chen (crimsun)]

On Wed, Nov 18, 2009 at 9:36 AM, Richard Clifford-Smith
<email address hidden> wrote:
> I have this same problem, also on Ubuntu 9.10 amd64. This is version 1.02 from the

You should probably try elevating audio privileges to RT similar to
what has been done for Lucid via RtKit. Search the web for "Ubuntu
Studio PAM limits.conf".

[Mahendra Tallur (mahen)]

Thanks, Richard !
This workaround did it for me. Still, I wonder why this is necessary, only for 9.10 (not 9.04) and only for VLC :-)

If anyone is interested, here's what I did :

I added the following line to /etc/security/limits.conf

# Support Temps réel pour le groupe audio
@audio - rtprio 100
@audio - nice -10
@audio - memlock 500000 #(à adapter; pour une valeur sans limite :"unlimited")

[Mahendra Tallur (mahen)]

Oops, sorry for making noise, but it actually didn't fix it. I should have double-checked before posting.
Richard may still give it a try, just in case.
Also my bugreport contained a bug : I meant "Thanks Daniel" ;)

[Richard Clifford-Smith (richard-cs)]

I added "@audio - rtprio 99" to the same file a couple of hours ago. I've been using vlc since then and haven't noticed the problem yet.

[Janosch Maier (phylu)]

The fix is not working for me.

[Daniel T Chen (crimsun)]

@Janosch Maier
Did you logout and login again?

[Janosch Maier (phylu)]

Ok. Forgot it. Now it is working.

[Richard Clifford-Smith (richard-cs)]

It was working but the problem now seems to have returned. /etc/security/limits.conf still contains the line I added before but the stuttering is back.

[zajc (jesenice)]

I have the same problem, Ubuntu 9.10, VLC 1.0.3 :( I haven't tried /etc/security/limits.conf method.

[Mahendra Tallur (mahen)]

zajc : You may check out VLC 1.0.5 on getdeb.net. I do not have this issue anymore.

[zajc (jesenice)]

@Mahendra Tallur: Thanks, it solved the problem :) After upgrade to 1.0.5 I had to restart computer and I have no problems with the sound (watching IPTV) anymore.

[Richard Clifford-Smith (richard-cs)]

Upgrading to VLC 1.0.5 doesn't solve the problem for me even after a restart. I still get the audio stuttering.

[Rémi Denis-Courmont (rdenis)]

Please provide the VLC logs

[rusivi2 (rusivi2-deactivatedaccount)]

We are closing this bug report because it lacks the information we need to investigate the problem, as described in the previous comments. Please reopen it if you can give us the missing information, and don't hesitate to submit bug reports in the future. To reopen the bug report you can click on the current status, under the Status column, and change the Status back to "New". Thanks again!