Corrupt audio with PortAudio and Behringer UMC404HD 4-channel USB Audio Interface
- PipeWire 0.3.35
- Debian Testing
- Plasma Desktop
Some clients - PortAudio most commonly, cause my UMC404HD USB sound card to go into a state where the audio is corrupted.
How Reproducible:
- Play some audio from Firefox in the background
- Run a PortAudio client such as
paex_sine
from the PortAudio examples collection. The mixed audio will play completely corrupted. -
paex_sine
exits after 5-seconds, but the audio continues to be corrupted, until I open up theplasma-pa
applet which seems to kick the sound card into resetting itself, and the audio goes back to normal.
Here is a recording of the audio collected with an external audio recorder connected over analog: 20210919-portaudio-breaks-pipewire.flac
Looking closely at the recorded audio, it appears to be "chopped up" with tiny sequences of samples in reverse order somehow:
This is very likely to be a driver bug. I have had similar problems with PulseAudio, with other applications such as Microsoft Teams, and also with my Zoom H4n recorder connected via USB to PulseAudio. It's just that running PortAudio clients on PipeWire is the most consistent method I've encountered so far to trigger the issue, and I'm hoping someone can help me figure out how to reproduce the issue at the lower level, so I can take it up with the kernel devs.