Arch Linux

anachromium

Member

Registered: 2021-03-08

Posts: 3

timidity & linux-rt: random playback issues

Hi everyone!

Don't really know, if this belongs here, in the "Kernel"-issues subforum or on the aur-entry of "linux-rt", so I'll try here first.

When I'm running the current linux-rt-kernel (5.11.4.11.arch1-1) I get random playback issues with timidity (timidity++ 2.15.0-5) (using PulseAudio and the pulseaudio-alsa plugin). When I play a MIDI file, everything works fine, until I stop it. When I start to play it again I get random noises instead of notes and timidity refuses to shut down correctly. (It stops playing, but it doesn't shutdown further than that as far as I can see.) Sometimes the noises come on the first try, sometimes only after I restart the file a couple of times. They do go away after a couple of tries, but they come back sooner or later.

This is not a big problem as I can - and probably should - use the standard-kernel when doing no jack-related stuff, but it's a weird thing anyway, so I though it couldn't harm to post it here. Maybe someone has any thoughts about this issue and ideas on how to track down why these problmes could arise.

All the best
anachromium

Morn

Member

Registered: 2012-09-02

Posts: 886

Re: timidity & linux-rt: random playback issues

Are you sure you even need the real-time kernel anymore? Real-time performance of the default kernel is much better than it used to be a few years ago. I use the standard kernel with the threadirqs kernel parameter (plus pipewire-jack etc.) and that seems to work very well.

I have had occasional weird random noise issues in the past in some audio apps, it might have been timidity (and Audacity I think). Typically my response is just to switch to something else, e.g. wildmidi for MIDI synthesis. Then again, the PipeWire migration may have fixed those issues for me...

Last edited by Morn (2021-03-26 15:55:56)

anachromium

Member

Registered: 2021-03-08

Posts: 3

Re: timidity & linux-rt: random playback issues

That's probably a good idea as I almost never need that super-low-latency for live purposes.
Though I'm curious, is PipeWire already usable for professional audio as a replacement for jack?

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,626

Re: timidity & linux-rt: random playback issues

FWIW I've personally had generally better experience with fluidsynth as a MIDI synth, which also has a native pulse backend that doesn't rely on the ALSA bridge which might be a possibility as well.

anachromium

Member

Registered: 2021-03-08

Posts: 3

Re: timidity & linux-rt: random playback issues

Thank you for your answer V1del and sorry for the long response time. (After switching over to the standard kernel as default I completely forgot about the topic.)
I'll probably try fluidsynth anyways!