Crackling / scratching noise using Pulseaudio

[Jamie Lawler]

Jaunty SRU information follows:

Impact: Users of certain Intel8x0 and Intel HDA controllers are experiencing crackling and popping while playing audio files. These symptoms appear when the mixer elements are unmuted. These anomalies are due to buffering and clock adjustment calculations that incorrectly assume that the underlying hardware is well-behaved.

Resolution/Fix: Improve the buffering and clock calculations by providing more conservative floors and ceilings. Changes are backported from linux-2.6.git and alsa-kmirror.git. Provenance is given in the commits listed below in the Changesets section. Users have fared well using test kernels from http://kernel.ubuntu.com/~dtchen/.

The original proposal is available at https://lists.ubuntu.com/archives/kernel-team/2009-April/005405.html.

Test case: If one's audio hardware is among the affected Intel8x0- or Intel HDA-based, simply playing music in GNOME using Rhythmbox will expose this behaviour.

Changesets:
 - http://kernel.ubuntu.com/git?p=dtchen/ubuntu-jaunty.git;a=commit;h=b77756ea8b7c973af68258febd7cd11d4b88893a
 - http://kernel.ubuntu.com/git?p=dtchen/ubuntu-jaunty.git;a=commit;h=c5197004ef2b0c4ebfb0fcb68715a0fce4c39cad
 - http://kernel.ubuntu.com/git?p=dtchen/ubuntu-jaunty.git;a=commit;h=3ed92131e73867a5fb6064642fd6873fcd194d75

ACKs:
 - https://lists.ubuntu.com/archives/kernel-team/2009-April/005414.html
 - https://lists.ubuntu.com/archives/kernel-team/2009-April/005427.html

Regression potential: Theoretically, there is extremely low probability for regression, as these patches simply remove the assumptions that the underlying hardware is well-behaved. Practically, users of jack-audio-connection-kit (JACK) and other native ALSA apps [not routed through PulseAudio as is the default in Ubuntu] may notice changes in jitter. Testing since Jaunty's release has revealed no regressions.

--
Original bug information follows:

I hope this isn't a dupe. A few people (myself included) are experiencing odd crackling / scratching noises when using pulseaudio. This frequently happens when you try to start a new piece of music or video. Sometimes it will crackle for a few seconds, then play as normal; sometimes it will fast-forward through a few minutes of the song then start playing; sometimes it will crackle then stop entirely and I have to kill pa.

Here's a URL of my output of alsa-info.sh: http://www.alsa-project.org/db/?f=44dc1549d60508bd181a03ee1c65465aa5c9024d

Here's a link to the ongoing thread at ubuntuforums: http://ubuntuforums.org/showthread.php?t=1084919&page=4

I have pulseaudio 0.9.14 from the main jaunty server.

ProblemType: Bug
Architecture: i386
DistroRelease: Ubuntu 9.04
MachineType: Packard Bell BV EasyNote MB85
NonfreeKernelModules: nvidia
Package: linux-image-2.6.28-11-generic 2.6.28-11.35
ProcCmdLine: root=UUID=36b4053e-7e48-4a1a-8666-b63058a30816 ro quiet splash
ProcEnviron:
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.28-11.35-generic
SourcePackage: linux

[Tuomas Aavikko (taavikko)]

Changing to confirmed as affected also.

[Tuomas Aavikko (taavikko)]

http://www.alsa-project.org/db/?f=219141dc773a67cbe6408724eb967cb46ed0646e

[Kristoffer Lundén (kristoffer-lunden)]

This affects me too.

http://www.alsa-project.org/db/?f=53c148322e2e243bff274e92894eba0063ed3166

[Mark Falcey (mfalcey)]

I am also having this problem but not on my ALC883 sound chip or my C-Media 8768 PCI sound card, only with my usb headset. If I do not open pavucontrol it works fine but if I do open pavucontrol and then close it the usb headset becomes glitchy and scratchy after a few seconds. If I then open pavucontrol sound returns to normal immediately and if I keep it open the sound is fine everywhere. I do have simultaneous output enabled in papref but it does not matter if I choose only usb or simultaneous or if I remove the simultaneous output.

This is on Jaunty with pulseaudio 0.9.14 and has persisted through the last two pulseaudio updates.

[morryis (morryis)]

I experience similar sound glitches with Jaunty. Rhythmbox, Totem and especially flashplugin_nonfree (when playing Flash videos in Firefox) are affected. The notification sound in pidgin creates that rasping sound too. This sound bug sometimes makes the application crash.

Sometimes when I play a video, there is only this clicking/rasping sound and the video is playing like in slow motion. I noticed a similar effect after pausing a video for a longer time. I then have to restart Totem multiple times to make it play the video properly again. There is sometimes also an error message: "Failed to connect stream: Invalid argument". This error appears sometimes when I fast-forward a video in Totem or a song in Rhythmbox. I attached the Totem debug messages.
Since I experienced bug 320875 ("alsa-util.c: snd_pcm_avail_update() returned a value that is exceptionally large:") until it was fixed and the fix is only a temporary workaround, the real cause may be the same.

[morryis (morryis)]

Output of utils_alsa-info.sh

[phenest (steve-clark)]

Here's my output of alsa-info.sh

http://www.alsa-project.org/db/?f=367d9b752df8d6c3677ba6f5ce5a009d95304e91

I have the same issue as the OP.

[Dylan McCall (dylanmccall)]

I have observed this problem since upgrading to the Jaunty alpha. I was able to work around it by going to Sound Preferences and changing to sound playback in the "Music and Movies" profile to OSS. Using ALSA directly gave me the same issue as with pulseaudio.

[Tuomas Aavikko (taavikko)]

PA had to be killed, and restarted to make it work again.
Usually when testing sound via "gstreamer-properties" (auto-detect" it produces a beep.
When using a "pulseaudio" it produces an error message, just forgot to log it :( )

[zp (zekopeko-deactivatedaccount)]

http://www.alsa-project.org/db/?f=73a7ff0833deb3d94aaf2420e416737e613792dd

[Dave Jeffery (kecske-bak)]

I've had this problem too.

Usually I can get the audio to start in Rhythmbox by restarting the file a few times until it finally plays, but occassionally you'll get loads of no entry signs appearing next to all of your tracks and you have to re-start.

[morryis (morryis)]

I also experience this problem when playing Flash-videos in Firefox, e.g. youtube. The video loads correctly. When the video starts to play, there is a scratching noise and after that only silence. The video playback than sometimes stops or displays only few frames and jumps. When I skip manually, it sometimes plays correctly for a few seconds. When I close the tab, the Firefox windows fades to gray and doesn't react anymore.

I experienced the same on a fresh Jaunty install on a friends laptop yesterday. This looks for me like a big and common problem and should recieve high attention/priority!

[Asif Youssuff (yoasif)]

Also affects me. See output of alsa-info.sh here:

http://www.alsa-project.org/db/?f=41eab7e4ad239353fc0bb93f2ab0fed7194aaa6b

[Umuntu-Tim- (thembinkosi)]

lspci, if there is any other file i can add please email me.

[Umuntu-Tim- (thembinkosi)]

dmesg

[Umuntu-Tim- (thembinkosi)]

I also noticed pulse starts crackling when i use the computer and there a peek on cpu usage.

[Mimue (michael-mueller12)]

Update of today for Jaunty Beta included also some changes in Alsa and pulseaudio. For me the sound works now properly, far better than before.
But I can still produce the crackling when playing too much around, meaning having open several windows with more than one source of sound active. Unfortunately I can't tell how to reproduce it reliably.

[Ryan (ubuntu-draziw)]

Have issue here too. I didn't reboot before collecting this...
Your ALSA information is located at:
http://www.alsa-project.org/db/?f=49ffd039a8c78b2e7f74e8ffe6c4ca9a80443221

VLC works fine, any can also play audio in totem, etc. But flash movie audio inside firefox is nothing but static, and audio in pidgen is static too.

[Ryan (ubuntu-draziw)]

Current boot, audio is working in vlc, etc - and in flash items. however, now my volume buttons trigger OSD notification changes, but do not affect the volume level (Dell Latitude D620). Right clicking volume and pulling up Volume Controller - using the HDA Intel (alsa mixer) Playback set to Master, the slider their does adjust volume level.

alsa-base.conf added
options snd-hda-intel power_save_controller=1
(read in post by Crimsum in forums)

Your ALSA information is located at http://www.alsa-project.org/db/?f=8f9ec0905132c49b3cca2b12bdaad29f9a6ac504

So this is progress, but how do I get my volume up/down buttons on the laptop to work again?

[zp (zekopeko-deactivatedaccount)]

this looks to be resolved with the latest jaunty up-dates

[Asif Youssuff (yoasif)]

Also looks to be resolved on my end with latest updates.

[Dylan McCall (dylanmccall)]

Definitely not resolved on my end :(

Crackling still happens, from the looks of it heavily influenced by CPU usage from other processes. Audio playback in videos is also crackly and gets out of sync / speeds up and slows down horribly.

alsa-info.sh output:
http://www.alsa-project.org/db/?f=7be8a26c7a881e91b7f82b61dbc0d5df245a7fe1

lspci output is attached.

[talent03 (talent03)]

I just came to say a me too. I have a m1330 dell and I get the same problems as @morryis above. I have the latest udpates as of April 8, 2009 for Jaunty.

[Fernando Miguel (fernandomiguel)]

I just installed dtchen kernel images, and it seems to help a lot with video playback. Sometimes i still get a bit of slowdown, but it quickly gets on track

mplayer presented me with this:
[pulse] working around probably broken pause functionality, see http://www.pulseaudio.org/ticket/440

$ uname -a
Linux blubug 2.6.28-12-generic #42~crimsun1lp345627 SMP Sat Apr 11 02:00:26 UTC 2009 x86_64 GNU/Linux

[Daniel T Chen (crimsun)]

Just for reference, I have test kernels at http://kernel.ubuntu.com/~dtchen/

Note the ABI bump - it is not in Jaunty, so you will need to track carefully further updates to Jaunty's kernel images.

[Dylan McCall (dylanmccall)]

Note that the "duplicate" bug report linked to this one is not just a duplicate; it links to patches!

<https://bugs.edge.launchpad.net/ubuntu/+source/linux-meta/+bug/360062>

Thanks for finding those, David :)

[David Nielsen (davidnielsen-deactivatedaccount)]

I know it's very late in the game to put these into Jaunty but I am hoping we can get those patches in somehow.

[Daniel T Chen (crimsun)]

On Sun, 12 Apr 2009, Dylan McCall wrote:

> Note that the "duplicate" bug report linked to this one is not just a
> duplicate; it links to patches!

It is a duplicate. I've already rolled kernels with those patches
(yesterday), and you haven't given any feedback...

[David Nielsen (davidnielsen-deactivatedaccount)]

For what it is worth, I have been using that kernel all day playing sound and there has not been any crashing of pulseaudio. The logs still show some errors regarding possible driver bugs but PA itself is stable and the sound is crackle and pop free.

[Dylan McCall (dylanmccall)]

Daniel,
I tried your kernel images and whatnot... I'm hesitant to say for certain, but that _seems_ to have resolved the synchronization issues I had with video playback. (The video itself still performs horribly compared to last release, but that's probably another bug).
Audio still gets the occasional (though somewhat rare / hard to trace) crackle on my end, particularly when there are many things going on.

[Conn O Griofa (psyke83)]

BUGabundo & others,

If you're noticing video stuttering in media players (with or without audio stuttering), it's possible that your graphics hardware's MTRR ranges aren't setup properly, which causes performance issues. It's feasible that this may accentuate audio skipping slightly.

I suggest everyone take a look at bug #314928 (especially those with Intel graphics adaptors) to see if you're affected.

[futurefx (force)]

i hope it is fixed in final release because when i install Ubuntu 9.04 to someone i disable updates and someone has expensive mobile internet and cannot afford updates.

[Daniel T Chen (crimsun)]

On Tue, 14 Apr 2009, futurefx wrote:

> i hope it is fixed in final release because when i install Ubuntu 9.04
> to someone i disable updates and someone has expensive mobile internet
> and cannot afford updates.

The fixes are too invasive beyond kernel freeze but will be in an SRU.

[futurefx (force)]

so you tell that ubuntu 9.04 will become broken release? do killing and removing pulseaudio helps

[Ryan (ubuntu-draziw)]

argh. My sound had been fixed by a prior mainstream update - and just broke again on the last batch. I'm back to having static, and no input sound device. :(

[Asif Youssuff (yoasif)]

I too am seeing the return of some stuttering while playing mp3s
(mocp). it seemed fixed for a while, but it seems to be back with my
latest updates.

On Tue, Apr 14, 2009 at 5:18 PM, Ryan <email address hidden> wrote:
> argh.  My sound had been fixed by a prior mainstream update - and just
> broke again on the last batch.  I'm back to having static, and no input
> sound device. :(
>
> --
> Crackling / scratching noise using Pulseaudio
> https://bugs.launchpad.net/bugs/345627
> You received this bug notification because you are a direct subscriber
> of the bug.
>

[Daniel T Chen (crimsun)]

@asif use the test kernel mentioned above

On Apr 14, 2009 11:25 PM, "Asif Youssuff" <email address hidden> wrote:

I too am seeing the return of some stuttering while playing mp3s
(mocp). it seemed fixed for a while, but it seems to be back with my
latest updates.

On Tue, Apr 14, 2009 at 5:18 PM, Ryan <email address hidden> wrote: > argh. My
sound had been fixed b...
> You received this bug notification because you are a direct subscriber
> of the bug.

> -- Crackling / scratching noise using Pulseaudio
https://bugs.launchpad.net/bugs/345627 You rece...

[Asif Youssuff (yoasif)]

Daniel, running your test kernel now, seems fixed. Not sure if it's related, but Cheese now picks up my webcam in my laptop as well. (It didn't with the previous kernel) Not sure what you're patching here, but it seems be doing some good.

[Asif Youssuff (yoasif)]

I spoke too soon, the audio is now stuttering a bit... no more crackling or scratching (yet), but now I'm getting a stutter.

[Asif Youssuff (yoasif)]

It was stuttering before with the crimsun kernel, and now it's a looot
worse, with skipping in mocp and flash playback of audio.

output of my uname -a

Linux ubuntu-asif 2.6.28-12-generic #42~crimsun2lp345627 SMP Tue Apr 14
22:20:27 UTC 2009 i686 GNU/Linux

I may have to go to the mainline kernel again because this is actually
worse than it was with recent updates.

Hope you guys can give me some other ideas to help troubleshoot.

[Daniel T Chen (crimsun)]

On Fri, 17 Apr 2009, Asif Youssuff wrote:

> It was stuttering before with the crimsun kernel, and now it's a looot
> worse, with skipping in mocp and flash playback of audio.
...
> I may have to go to the mainline kernel again because this is actually
> worse than it was with recent updates.

Please reproduce the symptom in 2.6.28-11.42-generic.

[Dylan McCall (dylanmccall)]

This seems to be resolved on my end with the latest official kernel release: 2.6.28-11.42

This is based on the fact that I just realized I've been watching a large video quite comfortably without audio issues. Cool :)
Will keep you posted if anything comes up, but I haven't had a single crackle so far.

[Asif Youssuff (yoasif)]

Still seeing stuttering.

http://www.alsa-project.org/db/?f=7c6337f8a38d7e1abfdf018bf5792ef35de099a1

On Fri, Apr 17, 2009 at 2:53 PM, Daniel T Chen <email address hidden> wrote:
>
> Please reproduce the symptom in 2.6.28-11.42-generic.

[Dave Gilbert (ubuntu-treblig)]

11.42 is still giving the occasional pop sound for me, where as Daniel's 12 special didn't.

[Murat Gunes (mgunes)]

I've had this problem with my M-Audio Quattro USB audio device since around the beginning of the Jaunty cycle. The only combination that works without glitches for me is the combination of Daniel's 2.6.28-12.43 kernel and PulseAudio 0.9.15 from Luke Yelavich's PPA.

My alsa-info.sh output: http://www.alsa-project.org/db/?f=8f80f8323f45b0cf03366bde3fe5b1991f2e45a9

[magicdarvin (magicdarvin)]

having the same bug

[tasadar_f (tasadarf)]

I have the same bug. This bug is horrible. I have kernel 2.6.28-11.42.

My sound card is realtek ALC1200

please fix this.

[Mr.Green (mr-greenhh)]

For me the problem is similar:
When playing the "new mail" sound in thunderdbird it often jitters and cracks.
When watching a video with VLC this problem occurs often (jitter, crackling); the same video with Totem seems to be fine.
Songbird sometimes cracks, but there it doesn't seem to be that often.

alsa.sh: http://www.alsa-project.org/db/?f=a8bbd251229a149f7ee20231df3def04a29c53f9

regards
Mr.Green

[tasadar_f (tasadarf)]

My alsa.sh

http://www.alsa-project.org/db/?f=fea10a92343cd389d834dd2ca1f20b1bda8dcfee

[Djainette (djainette)]

Same problem with a HP Compaq 6715b and a ADI 5.10.1.5161 sound card in jaunty upgraded from intredpid.
Videos (in VLC or Flash) play in fast-forward with crackling sound. Audacious also plays fast-forward crackling music.

[Stefan Bader (smb)]

This has been pulled into the repo

[Steve Langasek (vorlon)]

Accepted linux into jaunty-proposed, the package will build now and be available in a few hours. Please test and give feedback here. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you in advance!

[Mimue (michael-mueller12)]

I updated the -proposed packages and tests seemed to be successful. What I did:
- Sound effects on button click enabled
- Playing MP3 worked with totem.
- Playing a DVD movie worked with totem. Even pausing and resuming the movie was OK.
but...
- after some minutes playing the DVD movie suddenly the sound playing got cracked.

My laptop is a Toshiba Satellite M40 with an ATI-IXP sound chip.

[Mimue (michael-mueller12)]

Here is my alsa-info.txt associated with the previous comment.

[Kamil Páral (kamil.paral)]

I have also Intel HDA audio controller (Thinkpad R61) and also have heavy crackling problem (usually audio is crackling, sometimes it's silent, very occasionaly it's ok). But not in MP3 files (they play ok), but in AVI (containing MP3 usually). For example in this file:
http://games.on.net/file/8386/StarCraft_II_Cinematic_Trailer
or
http://www.starcraft2.com/movies.xml (Cinematic Trailer)

I don't know if it is the same problem. Proposed update didn't help. But I have found out that removing/renaming this file:
/usr/lib/gstreamer-0.10/libgstmpegaudioparse.so
solves the problem for me (AVI audio ok). Or removing whole gstreamer0.10-plugins-ugly package.

If you developers think it's another problem, I can report it separately.

[wirechief (wirechief)]

http://www.youtube.com/watch?v=2N1TJP1cxmo plays fine for me but the
http://games.on.net/file/8386/StarCraft_II_Cinematic_Trailer plays
scratchy, i have a R61e jaunty 9.04 with all the current fixs for mesa
and xserver-xorg

On Sat, May 2, 2009 at 5:34 PM, Kamil Páral <email address hidden> wrote:
> I have also Intel HDA audio controller (Thinkpad R61) and also have heavy crackling problem (usually audio is crackling, sometimes it's silent, very occasionaly it's ok). But not in MP3 files (they play ok), but in AVI (containing MP3 usually). For example in this file:
> http://games.on.net/file/8386/StarCraft_II_Cinematic_Trailer
> or
> http://www.starcraft2.com/movies.xml (Cinematic Trailer)
>
> I don't know if it is the same problem. Proposed update didn't help. But I have found out that removing/renaming this file:
> /usr/lib/gstreamer-0.10/libgstmpegaudioparse.so
> solves the problem for me (AVI audio ok). Or removing whole gstreamer0.10-plugins-ugly package.
>
> If you developers think it's another problem, I can report it
> separately.
>
> --
> Crackling / scratching noise using Pulseaudio
> https://bugs.launchpad.net/bugs/345627
> You received this bug notification because you are a direct subscriber
> of the bug.
>

--
Reach out and share life, care for others,

[Kamil Páral (kamil.paral)]

Verification done? By whom? Certainly not by me. Developers, please tell me if my issue is the same or different from this one and if I should report it separately (and against which package). Thank you.

[Martin Pitt (pitti)]

Mimue reported success in comment 54. Kamil, seems your situation is slightly different then. I let the audio gurus do the further analysis on this.

[Dave Gilbert (ubuntu-treblig)]

I'd say this is good on my machine - the only thing I'm still getting (which isn't a major problem but may be relevant or may be a separate issue) is that if I've got Rhythmbox playing and I hit mute on the volume applet I hear crackling rather than silence. With rhythmbox stopped I have silence (whether or not mute is on).

Dave

[Daniel T Chen (crimsun)]

Kamil, wirechief, your symptoms are very probably unrelated to this kernel update. If you were seeing those symptoms prior to the linux-image in jaunty-proposed and after applying the update, it cannot constitute a regression. Further, the fact that the symptoms are associated with particular media types suggests that you should tweak the fragments parameters in /etc/pulse/default.pa if you cannot reproduce the symptoms without pulseaudio running.

[Kamil Páral (kamil.paral)]

Daniel,
1. yes, problems were present before and after proposed kernel update
2. I removed pulseaudio package, killed pulseaudio processes, and the problem is still present. Therefore I don't think it is related to pulseaudio.

It seems that my bug is not related to this bug. (But it is a regression, at least compared to Intrepid.) Please tell me which package I should report my bug against (linux kernel, gstreamer ugly codecs)?. Thanks.

[Dave Gilbert (ubuntu-treblig)]

Damn - with the -43 I've just had a pulseaudio[4272]: cpulimit.c: Received request to terminate due to CPU overload.

I don't think I ever saw that in the Jaunty release kernels (did see it in the Alpha and occasionally in the -42 I think):

May 4 15:30:55 davros pulseaudio[4272]: cpulimit.c: Received request to terminate due to CPU overload.
May 4 15:31:27 davros pulseaudio[9142]: main.c: Called SUID root and real-time and/or high-priority scheduling was requested in the configuration. However, we lack the necessary privileges:
May 4 15:31:27 davros pulseaudio[9142]: main.c: We are not in group 'pulse-rt', PolicyKit refuse to grant us the requested privileges and we have no increase RLIMIT_NICE/RLIMIT_RTPRIO resource limits.
May 4 15:31:27 davros pulseaudio[9142]: main.c: For enabling real-time/high-priority scheduling please acquire the appropriate PolicyKit privileges, or become a member of 'pulse-rt', or increase the RLIMIT_NICE/RLIMIT_RTPRIO resource limits for this user.
May 4 15:31:28 davros pulseaudio[9145]: alsa-util.c: Device front:0 doesn't support 44100 Hz, changed to 48000 Hz.
May 4 15:31:28 davros pulseaudio[9145]: alsa-util.c: Cannot find fallback mixer control "PCM" or mixer control is no combination of switch/volume.
May 4 15:31:28 davros pulseaudio[9145]: alsa-util.c: Device front:0 doesn't support 44100 Hz, changed to 48000 Hz.

Dave

[tasadar_f (tasadarf)]

I install kernel update-proposed and I have the same problems

[Daniel T Chen (crimsun)]

Kamil, file a bug affecting gst-plugins-ugly0.10.

Dave, see bug 329896 and bug 344057.

To properly resolve all the symptoms, one needs this updated linux, an updated alsa-lib, and an updated pulseaudio. That's a karmic task.

[Dave Gilbert (ubuntu-treblig)]

Thanks Daniel,
  That's a bit grim - leaving Jaunty without reliable audio - although I sympathise with the difficulty of such a large set of changes.

My problem with the -43 fix is that it appears for me to trigger the CPU overload much more - and out of the two bugs the CPU overload problem is much worse than the occasional pop/crackly (however annoying they are).

Dave

[Daniel T Chen (crimsun)]

On Mon, 4 May 2009, Dave Gilbert wrote:

> My problem with the -43 fix is that it appears for me to trigger the CPU
> overload much more - and out of the two bugs the CPU overload problem is
> much worse than the occasional pop/crackly (however annoying they are).

That seems a bit odd, however. The ALSA-related changes in 12.43 are
precisely the ones in my test kernel (12.43~crimsun3lp345627). Are you
unable to trigger the cpulimit termination using the test kernel?

[Mimue (michael-mueller12)]

Martin,

Sorry for my misleading comment. In fact my comment no. 54 reported only a success right after the update. But after some minutes the problem occurred again.

And I have to add that after rebooting that the crackling even got worse. I get the impression that the problem seems to be solved only for some few minutes after installing an update.

[Dave Gilbert (ubuntu-treblig)]

Hi Daniel,
  As per my comment on #350274 (that I've now merged as dupe) on the 2009-04-12 I hit the same problem on the #42~crimsun1lp345627 but I haven't tried the #43~crimsun3lp345627.

Dave

[Daniel T Chen (crimsun)]

On Mon, 4 May 2009, Dave Gilbert wrote:

> As per my comment on #350274 (that I've now merged as dupe) on the 2009-04-12 I hit the same problem on the #42~crimsun1lp345627 but I haven't tried the #43~crimsun3lp345627.

Please see
https://bugs.edge.launchpad.net/ubuntu/+source/linux/+bug/344057/comments/13

[Mimue (michael-mueller12)]

Hi Daniel,

I changed the daemon.conf accordingly (see attachement). The speaker-test worked properly, I heard alternating noise out of my left and right speaker. When I did a reboot after that and tested my sound with System->Preferences->Sound->"Sound Events: Test" I heard at the beginning a clear tone but after about 5s it got crackling and the system didn't recover so far.

Wasn't my setting in the daemon.conf not properly set?

Greetings, Michael

[Daniel T Chen (crimsun)]

On Mon, May 4, 2009 at 5:36 PM, Mimue <email address hidden> wrote:
> System->Preferences->Sound->"Sound Events: Test" I heard at the
> beginning a clear tone but after about 5s it got crackling and the
> system didn't recover so far.

I've received reports that halving default-fragment-size-msec (to 5)
in /etc/pulse/daemon.conf is helping immensely on some HDA
controllers.

[sterios prosiniklis (steriosprosiniklis)]

Jaunty guest in VBox version 2.2.2 fully updated no patches applied.
Kernel 2.6.28.12 brakes sound as described in this thread.
Booting with previous Kernel 2.6.28.11, resolves the problem.
Vbox Audio controller ICH AC97

[Daniel T Chen (crimsun)]

On Wed, May 6, 2009 at 10:34 AM, sterios prosiniklis
<email address hidden> wrote:
> Jaunty guest in VBox version 2.2.2 fully updated no patches applied.
> Kernel 2.6.28.12 brakes sound as described in this thread.
> Booting with previous Kernel 2.6.28.11, resolves the problem.
> Vbox Audio controller  ICH AC97

Have you tried any of the *pulseaudio* fixes described?

[sterios prosiniklis (steriosprosiniklis)]

Tried this one: https://bugs.edge.launchpad.net/ubuntu/+source/linux/+bug/344057/comments/13
without any success. If further testing is required please ask specifically.
I am not an expert.

[sterios prosiniklis (steriosprosiniklis)]

Also tried this one without results: halving default-fragment-size-msec (to 5)
in /etc/pulse/daemon.conf is helping immensely on some HDA
controllers.

[Asif Youssuff (yoasif)]

Installed the new kernel from jaunty-proposed, didn't seem to do much to the stuttering.

However, I tried the suggestion over at: https://bugs.edge.launchpad.net/ubuntu/+source/linux/+bug/344057/comments/13 and have been listening to music on MOC for about half an hour with only about 3 dropouts -- no stutters, it's a dropout now.

Basically, the music seems to stop for about a second or two and then returns. I/O load seems to be what is making it occur.

Trying the default-fragment-size-msec tip right now, just wanted to post an update given the information I have currently.

[martron (imartron)]

I tried out the proposed kernel after being referred here from https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/367671 which has a more accurate description of my problem: pulseaudio getting killed after ~20 minutes with a custom -rt kernel.

Anyway, so far installing the proposed generic kernel and making the edits to defaults.conf has stopped this behaviour and I'm able to listen to full albums without pulseaudio dying.

In fact, I'm reasonably surprised at how well this generic kernel handles my firewire interface with minimum xruns in jack with pretty good latency (<10ms).

The only problem I have now is that opening or closing a flash application causes an XRUN (dropout). This was also the case with the real-time kernel.

[Asif Youssuff (yoasif)]

With the proposed kernel, the default-fragment-size-msec = 5, and resample-method = trivial, I am still getting stuttering.

The addition of default-fragment-size-msec = 5 seems to get rid of the dropouts that I get with the new kernel with resample-method = trivial, but instead of dropouts, I get stuttering back instead.

[Asif Youssuff (yoasif)]

I'm using Audacious right now, and with the proposed kernel, the default-fragment-size-msec = 5, and resample-method = trivial, I just got a long (5 second) period of crackling/stuttering, followed by the music coming back and then stopping. Audacious itself was stopped, so I'm not sure exactly what happened. I have seen this behavior before.

I'm not sure what bug was fixed, but it's not really fixed on my end yet -- is there another bug I can make this comment to, to get a better fix?

[tasadar_f (tasadarf)]

I test the new proposed kernel and I have the same problems. I test sound in pidgin. The result crackling and scratching noise

[martron (imartron)]

I'm not sure what happened, but pulseaudio has become more unstable again. Whenever I pause rhythmbox, pulseaudio just dies and I need to restart the daemon. This wasn't the case a couple days ago so I'm not sure what's up.

[martron (imartron)]

This is the line that pulseaudio gives when I pause rhythmbox:
---

D: sink-input.c: Requesting rewind due to corking
D: core.c: Hmm, no streams around, trying to vacuum.
shm.c: Assertion 'madvise(ptr, size, MADV_DONTNEED) == 0' failed at pulsecore/shm.c:257, function pa_shm_punch(). Aborting.

[Daniel T Chen (crimsun)]

On Fri, May 8, 2009 at 10:40 AM, martron <email address hidden> wrote:
> D: sink-input.c: Requesting rewind due to corking
> D: core.c: Hmm, no streams around, trying to vacuum.
> shm.c: Assertion 'madvise(ptr, size, MADV_DONTNEED) == 0' failed at pulsecore/shm.c:257, function pa_shm_punch(). Aborting.

Please file a separate bug for the above message. (BTW, it should be
resolved in karmic's pulseaudio.)

[Brian Curtis (bcurtiswx)]

Any chance the new pulse will get backported to Jaunty? (I can make a
backport request if none has been made already)

Research is what I'm doing when I don't know what I'm doing.
--Wernher Von Braun
"The second law of thermodynamics: If you think things are in a mess
now, JUST WAIT!!"

On Fri, May 8, 2009 at 12:37 PM, Daniel T Chen <email address hidden> wrote:
> On Fri, May 8, 2009 at 10:40 AM, martron <email address hidden> wrote:
>> D: sink-input.c: Requesting rewind due to corking
>> D: core.c: Hmm, no streams around, trying to vacuum.
>> shm.c: Assertion 'madvise(ptr, size, MADV_DONTNEED) == 0' failed at pulsecore/shm.c:257, function pa_shm_punch(). Aborting.
>
>
> Please file a separate bug for the above message. (BTW, it should be
> resolved in karmic's pulseaudio.)
>
> --
> Crackling / scratching noise using Pulseaudio
> https://bugs.launchpad.net/bugs/345627
> You received this bug notification because you are a direct subscriber
> of the bug.
>

[Daniel T Chen (crimsun)]

On Fri, May 8, 2009 at 12:46 PM, Brian Curtis <email address hidden> wrote:
> Any chance the new pulse will get backported to Jaunty? (I can make a
> backport request if none has been made already)

It's be evaluated (as I mentioned on identi.ca). Also, please try to
keep responses relevant to the SRU testing, thanks. :)

[Dave Gilbert (ubuntu-treblig)]

Hi,
  I've just tested with the 2.8.28-12.43 from proposed with

resample-method = trivial

and

default-fragment-size-msec = 5

and I was able to trigger the problem with rhythmbox stopping and just getting constant loud crackling and no music
out and this doesn't get going again. This happened while there was some reasonably heavy CPU (update-manager doing its stuff) - but I've never had that behaviour on an earlier kernel as previously mentioned.

I'm back on 2.6.28-11 #42 and with both of those resample-method and default-fragment-size-msec set as above, and I'm still getting the occasional crackle - i.e. back to the original bug.

Dave

[Mimue (michael-mueller12)]

Hi all,

I did also a test with kernel 2.6.28-12-generic #43 on my toshiba satellite M40 with ATI-IXP codec, without success.

I edited the following in /etc/pulse/daemon.conf:

resample-method = trivial
default-fragment-size-msec = 5

After that I did:

killall pulseaudio

...and finally:

speaker-test -c2

...resulted in a crackling/sporadic noise on left speaker. The right one was muted, it seems.

When setting realtime-priority = 0 in daemon.conf then the response time to the test command (speaker-test) is fast, which wasn't when using realtime-priority = 5.

Blessings, Michael

[Daniel T Chen (crimsun)]

As per note in #ubuntu-devel:

18:06 < dtchen> pitti: i'm afraid 345627 is going to have to be tagged verification-failed; even though linux-2.6.28-12.43-generic fixes the symptoms for some users, it presents an awesome regression for others. i feel it's better to live with known breakage than introduce a regression.

[tasadar_f (tasadarf)]

I think my problem is diferent. I have hda-intel realtek alc 1200.

My Problem is only with Pidgin because Pidgin has 22khz sounds. I convert 22khz to 44khz and fix the problem.

[Víctor (paravictor2)]

I've done a clean installation of Jaunty. With previous versions (8.04 and 8.10) I had no problem with the sound. But now (in Jaunty 9.04) each time a pidgin contact is connected (or emesene or aMSN), or a new mail arrives, there is a noise in the speakers very unpleasant, like a crackling.

I have all the defaults after the clean installation of Jaunty 9.04.

Audio Device:
Model: MCP51 High Definition Audio
Vendor: nVidia Corporation (ASUSTeK Computer Inc.)
Sound Device: ALC883

[Daniel T Chen (crimsun)]

Everyone, is the crackling reproducible when using "resampling = ffmpeg" in daemon.conf?

[wirechief (wirechief)]

I tried adding resampling =ffmpeg and then listening to
http://games.on.net/filepopup.php?video=8386
it crackles pretty bad.
is this correct ? should i have restarted anything in this test ?
; log-target = auto
; log-level = notice
; log-meta = no
; log-time = no
; log-backtrace = 0
resampling = ffmpeg
resample-method = src-linear
; disable-remixing = no
; disable-lfe-remixing = yes

On Wed, May 13, 2009 at 6:34 PM, Daniel T Chen <email address hidden> wrote:
> Everyone, is the crackling reproducible when using "resampling = ffmpeg"
> in daemon.conf?
>
> --
> Crackling / scratching noise using Pulseaudio
> https://bugs.launchpad.net/bugs/345627
> You received this bug notification because you are a direct subscriber
> of the bug.
>

--
Reach out and share life, care for others,

[wirechief (wirechief)]

the file was located here: /etc/pulse/daemon.conf

On Wed, May 13, 2009 at 7:26 PM, wirechief <email address hidden> wrote:
> I tried adding resampling =ffmpeg  and then listening to
> http://games.on.net/filepopup.php?video=8386
> it crackles pretty bad.
> is this correct ? should i have restarted anything in this test ?
> ; log-target = auto
> ; log-level = notice
> ; log-meta = no
> ; log-time = no
> ; log-backtrace = 0
> resampling = ffmpeg
> resample-method = src-linear
> ; disable-remixing = no
> ; disable-lfe-remixing = yes
>
>
> On Wed, May 13, 2009 at 6:34 PM, Daniel T Chen <email address hidden> wrote:
>> Everyone, is the crackling reproducible when using "resampling = ffmpeg"
>> in daemon.conf?
>>
>> --
>> Crackling / scratching noise using Pulseaudio
>> https://bugs.launchpad.net/bugs/345627
>> You received this bug notification because you are a direct subscriber
>> of the bug.
>>
>
>
>
> --
> Reach out and share life, care for others,
>

--
Reach out and share life, care for others,

[Daniel T Chen (crimsun)]

On Wed, May 13, 2009 at 7:26 PM, wirechief <email address hidden> wrote:
> resampling = ffmpeg

Sorry, the above was a brown paper bag goof. I meant:

resample-method = ffmpeg

[Daniel T Chen (crimsun)]

On Wed, May 13, 2009 at 7:26 PM, wirechief <email address hidden> wrote:
> is this correct ? should i have restarted anything in this test ?

Yes, you will need to 'pkill pulseaudio' after making the change to
daemon.conf. It needs to be restarted (or autospawned).

[Conn O Griofa (psyke83)]

Daniel,

The "src-linear" resampler (current setting in Jaunty) is really awful, too. It causes crackles for certain ranges in audio (e.g. explosions); by crackles I mean resampling artifacts, not stuttering or buffering problems. These crackles never occurred with ALSA's default dmix, and I mentioned some of my results regarding the different resamplers in the comments of bug #190754.

My understanding is that this is the rough "ranking" of resamplers, from best to worst (with CPU usage following the same trend, from high to low): src-sinc-best-quality, src-sinc-medium-quality, src-sinc-fastest, speex-float-{10-0}, speex-fixed-{10-0}, ffmpeg, src-zero-order-hold, src-linear, trivial.

As you can see, we're currently using the second-worst resampler. From personal testing, my conclusion was that speex-float-1 was the best resampler that balanced low CPU usage with audio quality (no distortion or crackles at certain ranges). For all the resamplers from speex-float-0 and below, crackles occured on both of my systems (using different codecs of snd-intel8x0).

I suggest if you have time (and find some appropriate audio samples), you test some of the resamplers to find the optimal default in PulseAudio.

[Daniel T Chen (crimsun)]

On Wed, May 13, 2009 at 11:55 PM, Conn <email address hidden> wrote:
> As you can see, we're currently using the second-worst resampler. From
> personal testing, my conclusion was that speex-float-1 was the best
> resampler that balanced low CPU usage with audio quality (no distortion
> or crackles at certain ranges). For all the resamplers from speex-
> float-0 and below, crackles occured on both of my systems (using
> different codecs of snd-intel8x0).

There are HDA users who do not experience the symptoms using ffmpeg.
There are also HDA users who experience the symptoms using
speex-float-*.

There is a hardware component involved.

> I suggest if you have time (and find some appropriate audio samples),
> you test some of the resamplers to find the optimal default in
> PulseAudio.

There does not seem to be an optimal default given the extraordinary
range of craptastic hardware, AC'97 and HDA alike. What is immediately
reproducible on certain Dell and ASUS hardware is practically
impossible to reproduce on my HP and IBM.

[Asif Youssuff (yoasif)]

With 2.6.28-12-generic #43-Ubuntu SMP, default-fragment-size-msec = 5 and resample-method = ffmpeg, I am experiencing a lot less of the effects the bug reports describe. I am getting minor crackling, and some stuttering, but much more rarely than at any point before these changes. It's not perfect yet, but a lot better than before.

[Jonathan Kyler (fblack947)]

I just added this comment over on Bug #301755, but feel that it might be applicable to this one too:

I just had good success with adding a parameter to /etc/modprobe.d/alsa-base.conf:

options snd-hda-intel position_fix=1

I got the idea from:
  http://ubuntuforums.org/showthread.php?t=843012

And the file located at:
  /usr/share/doc/alsa-base/driver/ALSA-Configuration.txt.gz (use gunzip to unzip it)

The section on snd-hda-intel contained the following:
     Note 2: If you get click noises on output, try the module option
     position_fix=1 or 2. position_fix=1 will use the SD_LPIB
     register value without FIFO size correction as the current
     DMA pointer. position_fix=2 will make the driver to use
     the position buffer instead of reading SD_LPIB register.
     (Usually SD_LPLIB register is more accurate than the
     position buffer.)

My current configuration: Ubuntu 8.10, alsa 1.0.20, pulse audio 0.9.10, using equalizer via ladspa

The module parameter appears to be extremely important.

Other things which may or may not be important:
In /etc/pulse/daemon.conf:
  resample-method = src-sinc-best-quality (I've also used speex-float-1)
  default-fragments = 5
  default-fragment-size-msec = 25

[Asif Youssuff (yoasif)]

Running the karmic alpha now, this bug is still present.

updated alsa info: http://www.alsa-project.org/db/?f=92604ab2b6cfd2f1c541ad386b011f8c8fbffda9

i'll try the changed options noted in this thread and report back, though.

[Mimue (michael-mueller12)]

With the attached conf file I have not experienced any crackling/stottering so far. It seems that the most important option for my laptop (Toshiba Satellite M40) is 'realtime-priority = 0'. I don't know what's the disadvantage of setting this priority to the max, but it works for me.

My system: Linux 2.6.28-12-generic #43-Ubuntu SMP Fri May 1 19:27:06 UTC 2009 i686 GNU/Linux

[Dave Gilbert (ubuntu-treblig)]

Hi,
  with position_fix=2 on the 2.6.28-11 #42 kernel I seem to be doing OK with a few clicks; but much more rare than without it - although that confuses me since looking at the source it looks like the default is the same behaviour!
(position_fix=1 is certain not very happy).

Dave

[Asif Youssuff (yoasif)]

On Karmic, I changed /etc/pulse/daemon.conf resample-method to ffmpeg in response to bug #376374.

After changing default-fragment-size-msec = 5, i still get stuttering. I also tried changing /etc/modprobe.d/alsa-base.conf to include both

options snd-hda-intel position_fix=1

and

options snd-hda-intel position_fix=2

(I tested both, one after another, with a sudo /sbin/alsa force-reload each time).

I still get stuttering with each of the above options.

[nullack (nullack)]

Like Asif I am also helping to test Karmic. However on the current development build I dont get stuttering audio, my symptoms are crackling / scratching regardless of what I seem to do within the various volume control settings.

[nullack (nullack)]

Daniel RE what you said about the problems with the default resample-method = value on certain hardware, surely there is a possible solution that the install should query what hardware there is and optimally default the value to be correct? Whats happening currently is that audio out of the box is a broken user experience.

Thanks very much to Conn, on my audigy 2 soundcard going from the default src-linear to speex-float-1 fixed all the crackling problems I had.

For anyone else with an Audigy 2 card and crackling, the fix is to gksudo gedit /etc/pulse/daemon.conf and edit the resample-method = src-linear to resample-method = speex-float-1.

[Conn O Griofa (psyke83)]

Daniel,

While I don't dispute your observation that a hardware component is involved with the distorted audio, I think that we can all agree that src-linear is the lowest-common denominator in terms of audio quality, and an alternative should be chosen. Lennart recommends against using this resampler on the PA development list; see: https://tango.0pointer.de/pipermail/pulseaudio-discuss/2009-April/003490.html

You say that some users don't notice src-linear resampler artifacts on certain hardware - I would counter that these users may not have testing with their PCM volume set above ~75% (IIRC, the PCM slider is set to around 75% in a stock install of Ubuntu), as the distortion won't kick in below this threshold.

Also, some reporters may be confusing "distortion" (in terms of resampler artifacts) with stuttering (buffering problems, etc.). In my case, I suffered from distortion and stuttering with a stock Karmic Alpha 1 install ;).

[Conn O Griofa (psyke83)]

This may be related as well: https://tango.0pointer.de/pipermail/pulseaudio-discuss/2009-May/003701.html

Perhaps we can cherry-pick that fix and see if it helps?

[Daniel T Chen (crimsun)]

On Wed, May 20, 2009 at 1:17 AM, Conn <email address hidden> wrote:
> While I don't dispute your observation that a hardware component is
> involved with the distorted audio, I think that we can all agree that
> src-linear is the lowest-common denominator in terms of audio quality,

See bug 376374 and my associated change in bzr.

> You say that some users don't notice src-linear resampler artifacts on
> certain hardware - I would counter that these users may not have testing
> with their PCM volume set above ~75% (IIRC, the PCM slider is set to
> around 75% in a stock install of Ubuntu), as the distortion won't kick
> in below this threshold.

I have access to three different HDA controller/codec combinations
(Nvidia/Conexant, Intel/IDT, and the last escapes me atm) where
setting both PCM and Master to 100% does not reveal artifacts. PA also
is not configured to do absurd attenuation.

> Also, some reporters may be confusing "distortion" (in terms of
> resampler artifacts) with stuttering (buffering problems, etc.).

Yes, this bug report has become severely polluted.

[Daniel T Chen (crimsun)]

On Tue, May 19, 2009 at 11:56 PM, nullack <email address hidden> wrote:
> Daniel RE what you said about the problems with the default resample-
> method = value on certain hardware, surely there is a possible solution
> that the install should query what hardware there is and optimally
> default the value to be correct?

Again, the problem is that what one _assumes_ to work for a given
combination nondeterministically does not work.

[Andrew Smart (andrew.j.smart)]

I am a user of Intel8x0 have exerienced distortion since I began using Ubuntu 6.06. http://en.wikipedia.org/wiki/Distortion#Audio_distortion

In the past, installing up to date ALSA and pulseaudio had eliminated the distortion for me.

I upgraded to jaunty. With the included jaunty versions of ALSA and pulseaudio, I had distortion.

I had no distortion after both installing the most recent ALSA from their site, and installing pulseaudio 0.9.15 from here:
https://launchpad.net/~themuso/+archive/ppa

-----------------------------
IMHO, changing the resampler to a higher quality algorithm for _everyone_ won't fix the problem with Intel8x0 and Intel HDA users. It will just eat up CPU time for everyone. Remember when the sample rate of audio that is being played (e.g. 44100 Hz) matches the setting the hardware is at (e.g. 44100 Hz), NO resampling happens (Why would it need to?).
*If you think changing the resampling algorithm will help you, check to see if it will do any good: Find a way to play a sound at the same frequency that your hardware is set at, if there is still distortion, changing the resampling algorithm will NOT help.
*If you experience distortion with different frequencies ( 44100 Hz audio and 48000 Hz hardware setting ) and you did NOT experience distortion with the same frequencies ( 44100 Hz audio and 44100 Hz hardware setting ), then changing your current resampling algorithm to a higher quality resampling algorithm will help (but it will likely take more CPU time).

http://en.wikipedia.org/wiki/Sample_rate_conversion

-----------------------------
Users of snd-intel8x0, if you want to, try changing parameters given by:
modinfo snd-intel8x0

After running the above, I saw (among other things):
parm: ac97_quirk:AC'97 workaround for strange hardware. (charp)
parm: buggy_semaphore:Enable workaround for hardwares with problematic codec semaphores. (bool)
parm: buggy_irq:Enable workaround for buggy interrupts on some motherboards. (bool)

You can set these parameters by adding a module to /etc/modprobe.d/ with a line similar to the following, then do 'sudo update-modules' ( you know, ubuntu's equivalent of /etc/modprobe.conf ):
options snd-intel8x0 ac97_clock=44100

I don't know if changing any of the parameters will help you, users of snd-intel8x0. However, those options look promising. I didn't change any myself. Installing pulseaudio 0.9.15 and up to date ALSA removed the distortion I was hearing. I don't know how to help you Intel HDA users. Perhaps you could follow similar steps?

------------------------------
Is it the kernel that needs fixing, or ALSA with respect to the odd hardware? Chat with those guys on their mailing list if you have not already.
Here is a discussion of theirs that I found informative:
http://<email address hidden>/msg10469.html

Oh, and take a look around each file in /proc/asound There is a TON of information related to your personal hardware in those files.

[Dave Gilbert (ubuntu-treblig)]

A bit off topic - but for those tempted to try Karmic to get around this, I'm not hearing any crackles; but am getting hit
by #374010 where pulse stops with snd_pcm_delay() returned a value that is exceptionally large.

Dave

[Daniel T Chen (crimsun)]

Dave, there's a newer test kernel based on jaunty-proposed (containing fixes that, unfortunately, will be reverted).

[ken sease (seasekr2)]

I am running an AMD 64 with Conexant Audio and Nvidia Graphics so I am
not sure this problem is the same.

Ken

On Thu, 2009-05-28 at 01:29 +0000, Daniel T Chen wrote:

> Dave, there's a newer test kernel based on jaunty-proposed (containing
> fixes that, unfortunately, will be reverted).
>
> ** Changed in: linux (Ubuntu)
> Status: Fix Committed => Triaged
>
> ** Changed in: linux (Ubuntu Jaunty)
> Importance: Undecided => Medium
>
> ** Changed in: linux (Ubuntu Jaunty)
> Status: Confirmed => Triaged
>
> ** Changed in: linux (Ubuntu Jaunty)
> Assignee: (unassigned) => Daniel T Chen (crimsun)
>

[Sean (svz90)]

Not sure if this is the same problem, but I'm having audio playback problems on my ForteMedia FM801-AU - sound in all applications suffers from occasional "hiccups". However, the most severe problem is that flash video seems to get stuck in "fast forward" after some time (playback of both audio and video is very fast and extremely choppy). Updating linux-image-generic to 2.6.28.12.16 in jaunty-proposed made the problem less severe (the system played a number of flash videos flawlessly, but then eventually suffered from the same fast-forward problem). Is this the same problem? Were there other packages that needed to be updated (other than linux-image) to fix the problem?

Sean

[carl99fan (carl99fan)]

I am having the same problem as Sean, for the most part. Also happens in Amarok for me. As long as I keep the sound Muted I can watch flash videos without problem. I am having the (cpulimit.c: Received request to terminate due to CPU overload) found in the log. Seems to have gotten gradually gotten worse noticing I had not gotten any updates since I had upgraded to Jaunty. After some research I found that I had a broken package that I had forgotten about. So I updated after fixing the broken package using the package manager. I had many updates about 274 megs worth and it included updates to my generic kernel. I have had this problem since and has gotten to the point I have no sound and I dare not enable it or I might even crash. Forcing a hard boot 2 times in the last 3 days. I have been searching everywhere and I find that Sean has the most similar problems.

[carl99fan (carl99fan)]

Had a problem while I was muted now. Gkrellm let me know to look for message.

May 30 23:02:05 sara-desktop pulseaudio[8504]: main.c: Called SUID root and real-time and/or high-priority scheduling was requested in the configuration. However, we lack the necessary privileges:
May 30 23:02:05 sara-desktop pulseaudio[8504]: main.c: We are not in group 'pulse-rt', PolicyKit refuse to grant us the requested privileges and we have no increase RLIMIT_NICE/RLIMIT_RTPRIO resource limits.
May 30 23:02:05 sara-desktop pulseaudio[8504]: main.c: For enabling real-time/high-priority scheduling please acquire the appropriate PolicyKit privileges, or become a member of 'pulse-rt', or increase the RLIMIT_NICE/RLIMIT_RTPRIO resource limits for this user.

Hope this helps or maybe you could direct me to someone who can help this bug.

[Martin Pitt (pitti)]

Accepted into jaunty-proposed:

 linux (2.6.28-13.44) jaunty-proposed; urgency=low
 .
   [ Stefan Bader ]
 .
   * Revert "SAUCE: [jaunty] ALSA: Add retry for Intel8x0 clock measurement"
   * Revert "SAUCE: [jaunty] ALSA: Fix clock and buffer calculations for
     Intel8x0"
   * Revert "SAUCE: [jaunty] ALSA: Fix buffer positions and checks"

This reverts the attempted fix for this and avoids the regression.

[Jacob (jacob-rau)]

This problem is definitely something to do with high CPU usage, at least on my machine. First, my specs: Dell Latitude D520, 1.66GHz Centrino Duo, 3GB of RAM, lspci lists my audio device as "00:1b.0 Audio device: Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller (rev 01)". Now, if you guys want, you can run me out of here--I am running an unofficial kernel build; it is "2.6.29-02062903-generic"; I installed it to combat the Intel graphics regression. If these two fixes are mutually exclusive, I am going to revert to 9.04 because that would make 9.10 unusable...

Let me know if you need more information.

[Jacob (jacob-rau)]

Forgot to say HOW I know it is a CPU-usage related problem...

If I am ripping a CD, my processor is being used just under 50% (and that means an entire core, as this is a dual-core system). When I am ripping CDs, this problem surfaces. I haven't seen this problem anywhere else, but I don't tend to stress my CPU when listening to music either. I will try some other ideas to stress it and see if the problem resurfaces.

As other people have hinted at, here is the behavior:
I start a track in either Rhythmbox or Totem. The counter stays at 0:00, or starts counting rather quickly (3-4 seconds per second). The audio is all crackling. CPU usage spikes well above 75%, and is fairly erratic. If I stop the track and start it back up, sometimes I can get it to play, but usually I have to restart the computer. I don't know how to kill PA and restart it, as I haven't had any problems until recently.

Sorry my original description was so lame...

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 2.6.28-13.44

---------------
linux (2.6.28-13.44) jaunty-proposed; urgency=low

  [ Stefan Bader ]

  * Revert "SAUCE: [jaunty] ALSA: Add retry for Intel8x0 clock measurement"
  * Revert "SAUCE: [jaunty] ALSA: Fix clock and buffer calculations for
    Intel8x0"
  * Revert "SAUCE: [jaunty] ALSA: Fix buffer positions and checks"

linux (2.6.28-12.43) jaunty-proposed; urgency=low

  [ Amit Kucheria ]

  * Enable SYN_COOKIES for iop32x and versatile flavours
    - LP: #361687
  * SAUCE: Quirk for BT USB device on MacbookPro to be reset before use
    - LP: #332443

  [ Brad Figg ]

  * [jaunty] Add missing mvsas (Marvel SAS 6440) module configuration.
    - LP: #352336

  [ Chuck Short ]

  * SAUCE: [USB] Unusual Device support for Gold MP3 Player Energy
    - LP: #125250

  [ Daniel T Chen ]

  * SAUCE: [jaunty] ALSA: Fix buffer positions and checks
    - LP: #345627
  * SAUCE: [jaunty] ALSA: Fix clock and buffer calculations for Intel8x0
    - LP: #345627
  * SAUCE: [jaunty] ALSA: Add retry for Intel8x0 clock measurement
    - LP: #345627

  [ Luke Yelavich ]

  * disable CONFIG_SND_HDA_INPUT_BEEP on amd64 and i386
    - LP: #331589

  [ Makito SHIOKAWA ]

  * [ARM] 5404/1: Fix condition in arm_elf_read_implies_exec() to set
    READ_IMPLIES_EXEC
    - LP: #364358

  [ Manoj Iyer ]

  * SAUCE: Added quirk to fix key release for Samsung NC20
    - LP: #360247

  [ Oleg Nesterov ]

  * posix timers: fix RLIMIT_CPU && fork()
    - LP: #361508

  [ Scott James Remnant ]

  * [Config] Disable libusual and the ub driver
    - LP: #364538

  [ Stefan Bader ]

  * Disable unwanted staging builds
    - LP: #366144
  * Remove prism2_usb driver from ubuntu and use the one from staging
    - LP: #325366
  * SAUCE: Make rtl8187se depend on WIRELESS_EXT
    - LP: #366144
  * Disable CONFIG_RTL8187SE for armel.versatile
    - LP: #366144

  [ Tejun Heo ]

  * libata: handle SEMB signature better
    - LP: #257790

  [ Tim Gardner ]

  * Set USB_SERIAL=m for i386/amd64
    - LP: #345002
  * SAUCE: Jaunty - aic79xx - set reset delay to 5 seconds, down from 15.
    - LP: #79542
  * SAUCE: (drop after 2.6.28) Wifi suspend/resume scan timeout fixes
    - LP: #336055
  * Sony laptop: Sony Vaio laptops do not enable wwan power by default.
    - LP: #364678

  [ Tyler Hicks ]

  * SAUCE: (drop after 2.6.28) eCryptfs: Larger buffer for encrypted
    symlink targets
    - LP: #357345

  [ Upstream Kernel Changes ]

  * V4L/DVB (9999): gspca - zc3xx: Webcam 046d:089d added.
    - LP: #326674
  * V4L/DVB (10044): gspca - pac7311: Webcam 093a:2620 added.
    - LP: #363195
  * hwmon: (it87) Add support for the ITE IT8720F
    - LP: #357766
  * vgacon: Return the upper half of 512 character fonts
    - LP: #355057
  * drm/i915: add support for G41 chipset
    - LP: #365958

 -- Stefan Bader <email address hidden> Mon, 25 May 2009 17:30:40 +0200

[Djainette (djainette)]

Still not fixed.
Sound is still playing in fast-forward in audacious/vlc, and flash videos run in fast-forward too to keep the sync with the sound.

[Conn O Griofa (psyke83)]

Luke & Daniel,

I've been experimenting with PulseAudio in Karmic and Fedora 11, and I'm making some observations/suggestions relevant to this bug report, and PulseAudio as a whole.

My basic codec identifier, for reference:
conn@inspiron:~/.pulse$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: I82801DBICH4 [Intel 82801DB-ICH4], device 0: Intel ICH [Intel 82801DB-ICH4]
  Subdevices: 0/1
  Subdevice #0: subdevice #0
card 0: I82801DBICH4 [Intel 82801DB-ICH4], device 4: Intel ICH - IEC958 [Intel 82801DB-ICH4 - IEC958]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

In Fedora 11 (which uses kernel 2.6.29 and PulseAudio 0.9.15 with glitch-free playback enabled and no resampler/fragment customizations, unlike Ubuntu), audio works perfectly without any stutters, and bug #374002 is not triggered on my system.

With Karmic using the default PulseAudio settings, I'm experiencing what I would call micro-stutters, where the sound appears to skip an extremely short duration (milliseconds) every 20 seconds or so - this never occurred on Intrepid or Hardy with PulseAudio, is 100% reproducible in Totem and other applications, and is definitely not due CPU starvation. Bug #374002 [1] is not triggered, but only because glitch-free playback is disabled.

On Karmic with kernel 2.6.30-10-generic, I modified PulseAudio's configuration to use a vanilla PulseAudio configuration that's equal to Fedora (tsched=1, and no customizations to the resampler or default-fragment* values). This eliminated the microstutters entirely, but it triggers bug #374002 on my laptop after some minutes of audio playback. Even Skype appears to work correctly for a short time, but the aforementioned bug always kicks in within a few minutes, which requires PulseAudio to be restarted manually.

Tonight I upgraded to kernel 2.6.31-1-generic and with the same vanilla configuration, microstutters are eliminated entirely *and* bug #374002 is no longer triggered on my system. Even the most troublesome application, Skype, works absolutely flawlessly with PulseAudio (when configured to use the "pulse" device). There are no stutters at all, and Skype maintains a single client connection to the PulseAudio server (I'm sure you've noticed the problem where Skype connects and disconnects to the server dozens or sometimes hundreds of times in the space of a few minutes, causing stuttering - this no longer occurs).

First, a question: why did kernel 2.6.30-10-generic trigger bug #374002, when it was supposed to be fixed since kernel 2.6.29 according to Fedora's bug report related to my particular codec [2]? As I said earlier, this bug did not occur when I tested Fedora 11 on my laptop.

Second, a proposal: let's enable glitch-free playback and revert the modifications to the default-resampler, default-fragments and default-fragment-size-msec parameters.

I understand that this will trigger the snd_pcm_delay/snd_pcm_avail errors in buggy drivers (even though my particular codec appears fixed), but we need to face facts:
a) interrupt-based playback in PulseAudio really is "glitchy", and audio quality is suffering for everyone on Karmic as a result;
b) the resampler/fragment modifications we ...

[Conn O Griofa (psyke83)]

Sorry, slight correction to my previous post. With kernel 2.6.31-1-generic and glitch-free PulseAudio, Skype does have the problem of hundreds of connections opening/closing - but there is absolutely no stuttering even under CPU load.

This issue is probably due to Skype's buggy implemention of the ALSA API; nevertheless, it just shows that glitch-free handles this problem more robustly than using custom fragment values and lower-quality resamplers (as long as your ALSA kernel driver works correctly).

[Daniel T Chen (crimsun)]

On Tue, Jun 30, 2009 at 10:52 PM, Conn<email address hidden> wrote:
> First, a question: why did kernel 2.6.30-10-generic trigger bug #374002,
> when it was supposed to be fixed since kernel 2.6.29 according to
> Fedora's bug report related to my particular codec [2]? As I said
> earlier, this bug did not occur when I tested Fedora 11 on my laptop.

2.6.30 does not contain all the core/pcm mid-layer fixes that 2.6.31-git does.

Note also that Fedora 11, Ubuntu Jaunty, and Ubuntu Karmic have
different audio stacks.

> Second, a proposal: let's enable glitch-free playback and revert the
> modifications to the default-resampler, default-fragments and default-
> fragment-size-msec parameters.

The latter two modifications don't make any difference when
glitch-free is enabled. I dogfood before putting changes into the
Ubuntu repository: to that end, for a bit I've tested 2.6.31-rc1-fix1
and glitch-free enabled with much improved results on a lot of
hardware (AC'97-, HDA-, USB-based).

So, yes, it makes sense to stop applying those two quilt patches to
Karmic's pulse source.

> (even though my particular codec appears fixed)

Distinction: we work around your broken controller (your codec is
quirky but not relevant here).

> a) interrupt-based playback in PulseAudio really is "glitchy", and audio quality is suffering for everyone on Karmic as a result;

Ubuntu also does not use HZ=1000 combined with NOHZ or PREEMPT, unlike Fedora.

> b) the resampler/fragment modifications we use in Ubuntu are poor workarounds [3] for the erratic buffering behaviour in certain applications (Skype) and CPU usage caused by interrupt-based playback in PulseAudio;

Agreed (in the past there were concerns about limiting CPU usage for
low-powered devices).

> c) There is no guarantee that we can resolve the current stuttering/buffering issues with interrupt-based playback, as it seems pretty obvious that the majority of development is focused on glitch-free playback in PulseAudio;

Agreed, it's really an intractable problem, because far too much
hardware is plain broken.

> d) We are depriving ourselves of the opportunity to co-operate with the PulseAudio, Fedora, ALSA and upstream kernel developers in squashing the remaining bugs in PulseAudio and the ALSA kernel drivers that glitch-free playback exposes.

Timing is perhaps the biggest factor. These changes are queued, but
they weren't going to be put into Karmic without a 2.6.31-rc1-based
kernel landing first.

> I am aware that some sound cards may never work correctly with glitch-
> free (due to poor hardware documentation), but perhaps we can consider a
> method to blacklist cards later on - let's cross that bridge when we
> come to it.

Presently there is no callback into the driver for such information,
so we are incapable of doing so. Also, there are far too many hardware
combinations. It's much easier to simply disable glitch-free for those
cards.

[Sean (svz90)]

Though I may be mistaken, don't the changes made by Stefan Bader in the recent kernel revision undo the fix? If so, doesn't that mean that status should still be Triaged, not Fix Released?

[ken sease (seasekr2)]

Good question. I am running along happy on my Jaunty 32bit. I have
noticed a couple of lockups when coming out of suspend the last couple
of days. Maybe because I installed VirtualBox and XP inside that. Not
sure what is causing the lockups yet...

I have a spare hard drive that I might install 64 bit Jaunty on because
I have never tried that before. It will be interesting to see how the
audio and video does. I have a DV6000 series HP Laptop with an AMD-64.

Ken

On Fri, 2009-07-03 at 18:35 +0000, Sean wrote:
> Though I may be mistaken, don't the changes made by Stefan Bader in the
> recent kernel revision undo the fix? If so, doesn't that mean that
> status should still be Triaged, not Fix Released?
>

[TheJointChief (thejointchief)]

I am running 9.04 (upgraded from 8.10) and have had sound/video issues ever
since, regardless of the application I am using. Basically, if I play a
video or music file, and pause, stop, or start a new video, the program
stops playing audio/video, or it plays it in a crackling way. I've tried
uninstalling the pulse audio stuff and reinstalling, but that didnt help nor
have any of the recent updates.

If anyone has any suggestions or questions, please ask away :)

-Wes

On Fri, Jul 3, 2009 at 7:47 PM, ken sease <email address hidden> wrote:

> Good question. I am running along happy on my Jaunty 32bit. I have
> noticed a couple of lockups when coming out of suspend the last couple
> of days. Maybe because I installed VirtualBox and XP inside that. Not
> sure what is causing the lockups yet...
>
> I have a spare hard drive that I might install 64 bit Jaunty on because
> I have never tried that before. It will be interesting to see how the
> audio and video does. I have a DV6000 series HP Laptop with an AMD-64.
>
> Ken
>
> On Fri, 2009-07-03 at 18:35 +0000, Sean wrote:
> > Though I may be mistaken, don't the changes made by Stefan Bader in the
> > recent kernel revision undo the fix? If so, doesn't that mean that
> > status should still be Triaged, not Fix Released?
> >
>
> --
> Crackling / scratching noise using Pulseaudio
> https://bugs.launchpad.net/bugs/345627
> You received this bug notification because you are a direct subscriber
> of a duplicate bug.
>

--
-TheJointChief

[ken sease (seasekr2)]

My only suggestion, from my experience, is to try to do a fresh complete
install, not an upgrade from 8.10. When I did the upgrade I had the
same problems but after doing a fresh from scratch install of Jaunty my
sound and video work fine.

Ken

On Sun, 2009-07-05 at 04:36 +0000, TheJointChief wrote:
> I am running 9.04 (upgraded from 8.10) and have had sound/video issues ever
> since, regardless of the application I am using. Basically, if I play a
> video or music file, and pause, stop, or start a new video, the program
> stops playing audio/video, or it plays it in a crackling way. I've tried
> uninstalling the pulse audio stuff and reinstalling, but that didnt help nor
> have any of the recent updates.
>
> If anyone has any suggestions or questions, please ask away :)
>
> -Wes
>
> On Fri, Jul 3, 2009 at 7:47 PM, ken sease <email address hidden> wrote:
>
> > Good question. I am running along happy on my Jaunty 32bit. I have
> > noticed a couple of lockups when coming out of suspend the last couple
> > of days. Maybe because I installed VirtualBox and XP inside that. Not
> > sure what is causing the lockups yet...
> >
> > I have a spare hard drive that I might install 64 bit Jaunty on because
> > I have never tried that before. It will be interesting to see how the
> > audio and video does. I have a DV6000 series HP Laptop with an AMD-64.
> >
> > Ken
> >
> > On Fri, 2009-07-03 at 18:35 +0000, Sean wrote:
> > > Though I may be mistaken, don't the changes made by Stefan Bader in the
> > > recent kernel revision undo the fix? If so, doesn't that mean that
> > > status should still be Triaged, not Fix Released?
> > >
> >
> > --
> > Crackling / scratching noise using Pulseaudio
> > https://bugs.launchpad.net/bugs/345627
> > You received this bug notification because you are a direct subscriber
> > of a duplicate bug.
> >
>
>
> --
> -TheJointChief
>
> --
> Crackling / scratching noise using Pulseaudio
> https://bugs.launchpad.net/bugs/345627
> You received this bug notification because you are a direct subscriber
> of a duplicate bug.
>
> Status in PulseAudio sound server: New
> Status in “linux” package in Ubuntu: Triaged
> Status in linux in Ubuntu Jaunty: Fix Released
>
> Bug description:
> Jaunty SRU information follows:
>
> Impact: Users of certain Intel8x0 and Intel HDA controllers are experiencing crackling and popping while playing audio files. These symptoms appear when the mixer elements are unmuted. These anomalies are due to buffering and clock adjustment calculations that incorrectly assume that the underlying hardware is well-behaved.
>
> Resolution/Fix: Improve the buffering and clock calculations by providing more conservative floors and ceilings. Changes are backported from linux-2.6.git and alsa-kmirror.git. Provenance is given in the commits listed below in the Changesets section. Users have fared well using test kernels from http://kernel.ubuntu.com/~dtchen/.
>
> The original proposal is available at https://lists.ubuntu.com/archives/kernel-team/2009-April/005405.html.
>
> Test case: If one's audio hardware is among the affected Intel8x0- or Intel HDA-based, simply playing music in GNOME using Rhythmbox...

[Dave Gilbert (ubuntu-treblig)]

I'm still hearing popping with current Karmic (2.6.31-2) kernel - it's very noticeable.

Dave

[Conn O Griofa (psyke83)]

Dave,

You won't see any improvement until you enable glitch-free audio (providing that glitch-free works for your hardware) - see the recent posts by myself and Daniel. Until this is done officially, you can edit the configuration files yourself:

1. Create a copy of the configuration files to your user's pulse folder:
$ cp /etc/pulse/* ~/.pulse/

2. Edit ~/.pulse/default.pa, do a search for "tsched=0" and change to "tsched=1".

3. (Optional). Edit ~/.pulse/daemon.conf and comment the "resample-method", "default-fragments" and "default-fragments-msec" lines, like so:

; resample-method = speex-float-1
; default-fragments = 8
; default-fragment-size-msec = 10

This should completely eliminate stuttering, as long as your audio card doesn't trigger certain kernel bugs (see my previous comment to see a related bug).

Note: be sure to delete the contents of ~/.pulse/ to revert these settings if there is a pulseaudio update, otherwise the newer configuration files in /etc/pulse will get ignored.

[Dave Gilbert (ubuntu-treblig)]

Hi Conn,
  Neither of those tweaks helped (I made them in the /etc/pulse files and then restarted pa with pactl exit).
I also tried setting the default sample rate to 48k that has helped a bit in the past; doesn't seem to make much odds.

Dave

[cmcginty (casey-mcginty)]

Just wondering if any has actually seen an improvement in this bug? I just updated and followed the suggestions from Conn, but still have stuttering on audio. The changes from Conn seamed to make it more noticeable actually. Is it just my system, or what?

Sorry, but this bug is going on 4 months now. Is there anyway this one can be killed soon?

[RdeWit (rdewit)]

Hi, I gave up on the current kernel with PulseAudio. I installed Linux Kernel 2.6.30 and reverted back to Alsa and that seems to work for me. This link explains how to install the new kernel: http://www.ramoonus.nl/2009/06/10/linux-kernel-2-6-30-installation-guide-for-ubuntu-and-debian-linux/.

I hope this helps someone.

[Djainette (djainette)]

I even removed pulseaudio to use Alsa instead => no fix.
Updated Jaunty with kernel version 2.6.28-14 and reinstalled pulseaudio => worked a few minutes and then the sound glitches started again.

I don't know if this problem is related to pulseaudio or if this is a kernel problem, but to me Jaunty has just been dead space on my hard drive for more than 3 months. I'm just totally ridiculous when I talk of free software around me.

[pt123 (pt123)]

why are the other bugs (where the video stutters) being assigned as a duplicate of this when this bug has been marked as fixed. When people are still experiencing Video stuttering and audio being out of sync?

[Djainette (djainette)]

Tried Karmic alpha 4 today... "Null output" for sound.
Probably because of https://bugs.launchpad.net/ubuntu/+source/udev/+bug/393665

[Djainette (djainette)]

With 2.6.28-15-generic on Jaunty,
when booting with acpi=off option, sound is OK
when booting with noapic option, sound is borked.
Can't boot without one of these.

[Dave Gilbert (ubuntu-treblig)]

I'm curious if my original bug that was marked as a dupe of this (clicks/pops - often associated with video)
might be helped by the fix that's just gone into 2.6.31-8.28 as a fix for 412492 which increases a latency figure for intel video; in the case of video it got some flicker/dropping on the video.

(The current set of updates with 2.6.31-8 do seem to be better for my audio - I wonder if it was that fix or something else or another package update).

Dave

[Djainette (djainette)]

Tried the karmic 20090829.2 daily build : the sound seems to work fine (except a single loud crackle when the device is awaken). Just installed it instead of jaunty, more reports once I get to activate the proprietary wifi drivers from an ethernet connection.

[cmcginty (casey-mcginty)]

+1 for post <a href="https://bugs.launchpad.net/ubuntu/+source/linux/+bug/345627/comments/139">#139</a>.

I applied the "acpi=off" to my grub boot and it seems to have fixed all my sound issues.

[nullack (nullack)]

Daniel this is happening on Karmic. I get popping / scratching on all audio following the first desktop attempt to play a sound. I have an audigy 2 soundcard.

[Brad Bowman (launchpad-bereft)]

Crackly sounds on a fresh Jaunty install. I've tried various things but
haven't upgraded the kernel/alsa yet.

I'm still not clear that this is the bug I'm having, is there diagnostic
test other than upgrading the kernel?

I changed /etc/pulse/client.conf to "autospawn = no" and ran
aplay and still got some skips and crackles, hopefully this is
showing it's not pulseaudio in my case (?).
Is this the right way to test alsa without pulseaudio involved?
(With autospawn still "no", I ran pulseaudio --start, then aplay,
then pulseaudio --kill and audio stopped as expected)

The "Sound Playback" test sound in System > Preferences > Sound (gnome)
was choppy/stuttering/glitchy via Auto, Alsa, OSS and PulseAudio (when running).
It sounds like morse code. One oddity is that the drop-out only occurs at
volume levels over about 80%, with glitches getting more frequent up to 100%.

http://www.alsa-project.org/db/?f=7cb7e160ca7c796d8a76619080c54086e374dadb

"ubuntu-bug alsa-base", recommended at https://launchpad.net/~crimsun,
wasn't showing me this bug to attach to, I guess because it's "Fix Released"?

$ pulseaudio --dump-conf | egrep 'real|prior|resample|nice'
I: caps.c: Limited capabilities successfully to CAP_SYS_NICE.
I: caps.c: Dropping root privileges.
I: caps.c: Limited capabilities successfully to CAP_SYS_NICE.
high-priority = yes
nice-level = -11
realtime-scheduling = no
realtime-priority = 5
resample-method = auto
rlimit-nice = 31

[Brad Bowman (launchpad-bereft)]

It seems this bug doesn't apply to me, and that I just needed to find the right
documentation, then set the model= parameter. Sorry for the waste of time.

I'll note my solution in case it helps random web searchers, but it's NOT
related to this bug. I should also qualify these hints: I just found something
that worked for me and don't deeply understand what is going on.

==
The document with the hint required was ALSA-Configuration.txt's
"Module snd-hda-intel" section, online at:
  http://www.kernel.org/doc/Documentation/sound/alsa/ALSA-Configuration.txt
or /usr/share/doc/alsa-base/driver/ALSA-Configuration.txt.gz locally.
(It's mentioned in https://help.ubuntu.com/community/SoundTroubleshooting)

I set the option in a new file (/etc/modprobe.d/alsa-hda-intel-model.conf):
  options snd-hda-intel model=6stack-dig
(the first one I tried worked with my headphones, that's all I need)

I applied the change with:
$ sudo alsa force-reload # BEWARE kills you're audio using processes
$ cat /sys/module/snd_hda_intel/parameters/model

This fixed the stutters/crackles at high volume for via both alsa and pulse.

I've since discovered the excruciating details:
http://www.kernel.org/doc/Documentation/sound/alsa/HD-Audio.txt
http://www.kernel.org/doc/Documentation/sound/alsa/HD-Audio-Models.txt

(Things that didn't help:
* Jaunty proposed kernel (I think I already had the patches discussed above)
   2.6.28-15-generic #52-Ubuntu SMP Wed Sep 9 10:48:52 UTC 2009 x86_64 GNU/Linux
* snd-hda-intel position_fix parameter, description sounded relevant though)

[TheCheeze (mrcheeze)]

I am currently having this bug on Karmic Final Release using an HDA Nvidia Conexant sound card in my HP Pavilion DV2000 Series laptop. The sound crackles on notifications and they tend to play at double-speed as well.

[Daniel T Chen (crimsun)]

@TheCheeze Those symptoms read like a hardware issue, not PA-related
(though PA does push ALSA harder than anything). You may need one/both
of position_fix/bdl_pos_adj module parameters.

[ken sease (seasekr2)]

same problem on my dv6000 but does not occur on my 9.04 install...

TheCheeze wrote:
> I am currently having this bug on Karmic Final Release using an HDA
> Nvidia Conexant sound card in my HP Pavilion DV2000 Series laptop. The
> sound crackles on notifications and they tend to play at double-speed as
> well.
>
>

[efexorce (mustafa-ulker)]

have u tried this
https://help.ubuntu.com/community/SoundTroubleshooting

[bntly (ev3rsion)]

The fixes in this thread have removed the major beeps/glitches/cracking, but i am still getting 'glitching' in the audio during movie playback with both VLC/Mplayer. Where gltiching is an undulating in the audio (So, high lows synced to CPU usage it seems).

I'm using onboard audio on an EVGA N560sli (with nvidia chipset..)

Since my Xi-F isn't supported! Damn SB!

[bntly (ev3rsion)]

Futher: This does not happen during pure audio playback -> only when Video is thrown in the mix.

[anthony burman (antburman)]

ubuntu-bug pulseaudio

I don't know how to file a bug report. That's what I was asked to enter from askUbuntu forum.

I have Ubuntu 10.10, upgraded from 10.4. When I play Rythmbox the sound cuts and cracks or crackles if eg Firefox or Software Manager or my Photos files are open. I have Linux Kernel 2.6.35-23generic Gnome 2,32.0. Memory is 496.1 Mb. Processor is Intel (R) Celeron (R) CPU 430@ 1.80GHz. My graphic card is a Nvidia gigabyte Geforce GT 210.

Help!

[ken sease (seasekr2)]

My brain is getting taxed now. I remember the problem but haven't seen
it for quite some time. I presently installed Maverick, from scratch,
and have not seen any issues on my old HP laptop. Have you tried
installing from scratch rather than upgrading?

Ken

[anthony burman (antburman)]

Upgrade-reinstall was recently executed with Ubuntu 11.04. Problem is cured.

[Brad Figg (brad-figg)]

This bug was filed against a series that is no longer supported and so is being marked as Won't Fix. If this issue still exists in a supported series, please file a new bug.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.