Intermittent crackling with USB interface Tascam Model 12
- PipeWire version (
pipewire --version
):pipewire Compiled with libpipewire 0.3.43 Linked with libpipewire 0.3.43
- Distribution and distribution version (
PRETTY_NAME
from/etc/os-release
):Debian GNU/Linux bookworm/sid
- Desktop Environment:
Gnome 41.2
- Kernel version (
uname -r
):5.16.0-rc8-rt-amd64
Description of Problem:
When using Pipewire I regularly get glitches and crackling sounds, and none of the workarounds I tried seemed to have an effect. PulseAudio and Jack handle the device fine and I'm running a realtime kernel, so this looks like either a bug in Pipewire, or some kind of weird interaction between Pipewire and the device driver.
I originally encountered the glitches with Jack apps (Bitwig, Ardour, Audacity), but then noticed it happening in my music player too (Quod Libet, which uses GStreamer), and was able to reproduce it with pw-play
.
Here's a sine wave played back through pw-play
and routed through the mixer for recording (I couldn't record the monitor output directly, Audacity would record the dropouts as skips):
Hardware information
The Tascam Model 12 is a mixer with a 12 input / 10 output USB audio interface. Pipewire falls back to the stereo profile by default but I'm using the Pro Audio profile, with a loopback device to make a microphone input available to desktop apps.
The device supports 44100 / 48000 sample rates and 16 / 24 bit depths, but I've set it to stay fixed at 48000 / 24 because the mixer will complain when the format changes.
How Reproducible:
It seems to start happening pretty randomly, even when I'm just listening to music and not running any Jack apps.
It also happens with:
-
clock.force-quantum
set to 2048, 1024, 512. -
api.alsa.period-size
set to various values. -
api.alsa.headroom
set to non-zero values. -
api.alsa.disable-batch
set totrue
. - Disabling the loopback device.
- CPU governor set to
performance
. - Pipewire 0.3.42 (I was hoping the recent USB changes would help, but apparently not)
- Linux 5.15 (ditto)
Steps to Reproduce:
- TBD, I haven't yet found a specific way to trigger the problem.
Actual Results:
Regular crackling, dropouts, errors in pw-top
.
The errors don't always correspond with an audible dropout, and I sometimes hear dropouts without a corresponding error.
Expected Results:
No crackling.
Additional Info (as attachments):
-
pw-dump > pw-dump.log
: pw-dump.log