Professional audio setup (JACK, PipeWire)

[Gabriel Wicki]

Hello dear fellow Guix


My wish is simple: i'd love to get back at live-coding audio using
SuperCollider.  Thankfully all the necessities for that intent are
readily available in GNU Guix.  Unfortunately i'm unable to get it to
sound...

SuperCollider needs some layer in between itself and ALSA and it refuses
to work with PulseAudio.  Traditionally that'd been JACK, but as of
recently there have been reports of it working perfectly with PipeWire.
I would love to give that a try, but would also not mind the JACK route.
The problem is none of my attempts have worked so far.

What works: ALSA works fine (i can hear files playing with `aplay -D
mysetup test.wav`), as does PulseAudio.  When i start pipewire i get the
following output:


[W][86737.352484] mod.rtkit    | [  module-rtkit.c:  205 translate_error()] 
RTKit error: org.freedesktop.DBus.Error.ServiceUnknown
[W][86737.352557] mod.rtkit    | [  module-rtkit.c:  465 set_nice()] could not 
set nice-level to -11: No such file or directory
[W][86737.352950] mod.rtkit    | [  module-rtkit.c:  205 translate_error()] 
RTKit error: org.freedesktop.DBus.Error.ServiceUnknown
[W][86737.355742] mod.rtkit    | [  module-rtkit.c:  205 translate_error()] 
RTKit error: org.freedesktop.DBus.Error.ServiceUnknown
[W][86737.356146] mod.rtkit    | [  module-rtkit.c:  205 translate_error()] 
RTKit error: org.freedesktop.DBus.Error.ServiceUnknown
[W][86737.356162] mod.rtkit    | [  module-rtkit.c:  625 impl_acquire_rt()] 
could not make thread realtime: No such file or directory

These are "just" warnings; attempting to play audio results in this
peculiar error message:
connect(2) call to /dev/shm/jack-1000/default/jack_0 failed (err=No such
file or directory)


My internet searches left me clueless; thus my first question: is anyone
using PipeWire successfully?  I've found a home-service[1] which apparently
makes use of it but i wasn't successful to use it, yet


I am able to run JACK (by invoking `jackd -dalsa -dhw:1,0 -r44100`, the
same output settings that work for the aplay test directly on ALSA), i'm
even able to start the SuperCollider server, play some audio (everything
seems perfect: it connects itself to inputs as well as outputs), but
there's no sound.  Does anybody have a working JACK setup and would mind
giving me pointers on what i'm missing, or maybe share their
configuration?


I really don't mind which route to take, i only want to mess with some
sound on my favorite OS.


I have installed every- and anything i thought could maybe remotely help
to improve my situation (which it of course didn't): alsa-lib,
alsa-plugins, alsa-utils, jack, jack2, pamixer, patchage, pipewire,
pulseaudio, qjackctl, pavucontrol, wireplumber.


My user account is part of the "audio" group which comes with the
following entries in my pam-limits-service:

(pam-limits-entry "@audio" 'both 'rtprio 99)
(pam-limits-entry "@audio" 'both 'memlock 'unlimited)
(pam-limits-entry "@audio" 'hard 'nice -12)



I hope you and your setups are doing finer that me and mine :)

gabriel



[1] https://git.sr.ht/~krevedkokun/dotfiles/home/services/pipewire.scm