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FS#41075 - [alsa-plugins] 1.0.28-1 audio crackling in jack plugin

Attached to Project: Arch Linux
Opened by Nick Joliat (njoliat) - Thursday, 03 July 2014, 18:52 GMT
Last edited by Doug Newgard (Scimmia) - Thursday, 03 July 2014, 23:54 GMT
Task Type Bug Report
Category Packages: Extra
Status Assigned
Assigned To Tobias Powalowski (tpowa)
Jan Alexander Steffens (heftig)
Architecture All
Severity Low
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 0%
Votes 3
Private No


When I play audio through ALSA programs when JACK is playing (usings alsa-plugins jack plugin), after a period of normal playback (usually less than 3 minutes) audio starts crackling. This crackling continues indefinitely or until certain events (e.g. pause/play in MPlayer; seems to correspond to JACK graph changes.) I had not observed this problem prior to upgrading to alsa-plugins 1.0.28-1.

Additional info:

* example of audio crackle:
* same audio without crackle for comparison:

* package versions:
alsa-plugins 1.0.28-1
alsa-lib 1.0.28-1
ffmpeg 1:2.2.4-1
libpulse 5.0-1
libsamplerate 0.1.8-3
libspeex 1.2rc1-4

* other system info:
Lenovo T420s
soundcard: Intel PCH Conexant CX20590

* I do not observe this behavior if I downgrade alsa-plugins to previous version 1.0.27-2.

* tested with ALSA + no JACK (by commenting out /etc/asound.conf), and with JACK programs (e.g. "mplayer -ao jack") and the problem does not occur.

* .asoundrc:
pcm.dmixout {
# Just pass this on to the system dmix
type plug
slave {
pcm "dmix"

* /etc/asound.conf:
pcm.!default {
type plug
slave { pcm "jack" }

ctl.mixer0 {
type hw
card 1

# pcm type jack
pcm.jack {
type jack
playback_ports {
0 system:playback_1
1 system:playback_2
capture_ports {
0 system:capture_1
1 system:capture_2

* output of "aplay -l":
**** List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: CX20590 Analog [CX20590 Analog]
Subdevices: 0/1
Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 7: HDMI 1 [HDMI 1]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 8: HDMI 2 [HDMI 2]
Subdevices: 1/1
Subdevice #0: subdevice #0

* attached: Jackd output (I saw no change in printouts when crackling started)

Steps to reproduce:
* start jack with e.g. "jackd -d alsa -r 48000"
* run mplayer "mplayer -ao alsa [an mp3 or wav at least 3-4 minutes in length]"
* listen w/o interrupting playback, usually < 4 min.
This task depends upon

Comment by Nick Joliat (njoliat) - Thursday, 03 July 2014, 19:18 GMT
Sorry, think I should have attached the audio files instead of linking; attaching here.
Comment by Christian Fillion (cfillion) - Monday, 25 August 2014, 03:28 GMT
I am getting the same issue. It seems to happen at random with any alsa applications (web browsers, timidity, mpv with --ao=alsa...).
Downgrading alsa-plugins to 1.0.27-2 works, but it also brings back the (less annoying) "jack_client_new: deprecated" bug that was fixed in the new version.
Comment by Christian Fillion (cfillion) - Wednesday, 24 September 2014, 06:10 GMT
This seems to be a better solution:
There is a small delay added to the audio by using the loopback device, but it's nothing compared to alsa-plugin's annoying random noises.
Comment by Jacob Wirth (xthexder) - Sunday, 02 August 2015, 23:43 GMT
I've been running my system with 1.0.27-2 for over a year now, and this exact issue occurs on both my linux machines.
I thought I'd try 1.0.29-2 on the off-chance that this was fixed, but it looks like it is still a problem.

Since it might be useful for others, I've attched an archive copy of the 1.0.27-2 package that doesn't have this issue.