Package: pipewire Version: 1.2.4-1~bpo12+1 Severity: important X-Debbugs-Cc: cardboardaardv...@gmail.com
Dear Maintainer, Starting around July or August 2024 I started getting routine but mild crackling out of my speakers. This lasted for several weeks and then went away on it's own. Starting around two weeks ago (approximately September 10, 2024) the crackling returned with a vengence. The most recent symptoms include anything from very mild crackling every few minutes to heavy crackling occuring constantly. Some times the crackling begins immediately upon rebooting my system or restarting pipewire-pulse and some times it can take up to 12 hours for crackling to occur. There is a correlation between system load and how frequently the crackling shows up and how severe the crackling is. During my testing today I used this command to place my system under load resulting in load averages around 40 and most of the CPU time being spent in the kernel: while true; do echo loop; (find /usr -type f | xargs -P 500 -I % -exec cat "%") > /dev/null; sleep 1; done I've experienced this crackling with: * Firefox ESR from apt * VLC from apt * Telegram when playing audio notifications, installed from apt * Foobar2000 running under wine-devel from apt * Skyrim running under Proton experimental from Steam * REAPER with Jack Audio output selected using pipewire-jack as the audio backend The problem does not appear to occur when using REAPER with ALSA selected as the audio backend. As well REAPER using jackd2 from apt does not appear to have this problem. I've been unable to confirm that VLC when using the ALSA backend does not crackle as VLC fails to open the ALSA audio device when I try. In general it has been challenging to find other programs to do more extensive testing because so much stuff now assumes PulseAudio will be available. REAPER in ALSA mode runs itself using realtime scheduling priority. Jackd2 is also running with realtime scheduling priority. As best I can tell pipewire and pipewire-pulse should be running itself with realtime scheduling priority but I don't know how to confirm this is actually happening. REAPER using ALSA and jackd2 delivers reliable audio during my testing even when I experience X GUI pauses exceeding several seconds. REAPER using pulsewire-jack and the other applications using pipewire-pulse will start crackling even when there is no appreciable load on the system. When running the find/xargs load generator the applications using pipewire-pulse and REAPER using pipewire-jack go into extreme levels of crackling to severe distortion. I've used the same media playing inside Firefox, VLC and REAPER to ensure the audio crackling is not present in the source material. As well at this point I'm fairly confident the bug does not originate with the kernel since REAPER using ALSA and jack2 has proven reliable. However I have tested different stable kernel releases and the backports kernel and there appears to be some correlation to kernel releases in the stable branch. Using the backports kernel (6.10 series at this time) does not appear to change the behavior at all compared to the 6.1.0-25-amd64 kernel build from stable. Likewise, using 6.1.0-23-amd64 does not appear to change the behavior. In my testing today using 6.1.0-17-amd64 resulted in much worse audio crackling that the beforementioned kernels. But then also 6.1.0-17-amd64 would have been the kernel I was using in the past well before I ever experienced the audio crackling. I'm pretty sure when I was running 6.1.0-17-amd64 and did not experience the crackling issue I was also using pipewire from backports however I've been unable to confirm this from the apt logs as they do not appear to have timestamps for the log entries. Usually, but not not always, I am able to temporarily resolve the crackling issue by running "systemctl --user restart pipewire-pulse" - specifically, earlier today when the crackling was very bad and very frequent doing the restarts did not help at all. At this moment, about 8 hours later, the audio crackling from Firefox is light and infrequent, and I just performed a restart and it has not resolved the issue. I have previously tried increasing the pipewire quantum to 8192 in an effort to prevent the crackling but it does not appear to have any effect at all. My first change was by running "pw-metadata -n settings 0 clock.quantum 8192" and later I modified the default pipewire.conf to set default.clock.quantum and default.clock.max-quantum to 8192 and that also did not seem to have any effect. I'm not sure what else I can do to test this, issolate the fault, or try to resolve the issue. If you have any thoughts please let me know. This issue is fairly annoying as my workstation's most frequent use case is for playing or editing multimedia. -- System Information: Debian Release: 12.7 APT prefers stable-updates APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 6.1.0-25-amd64 (SMP w/4 CPU threads; PREEMPT) Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE not set Shell: /bin/sh linked to /usr/bin/dash Init: systemd (via /run/systemd/system) LSM: AppArmor: enabled Versions of packages pipewire depends on: ii adduser 3.134 ii init-system-helpers 1.65.2 ii libpipewire-0.3-modules 1.2.4-1~bpo12+1 ii pipewire-bin 1.2.4-1~bpo12+1 pipewire recommends no packages. pipewire suggests no packages. -- no debconf information
