[SOLVED] How to use JACK audio device with pipewire?

[chconnor]

I've been using a Focusrite Scarlett 18i8 through Jack. Just upgraded from 22.04 to 22.10 and with the new pipewire the setup no longer works (no audio, can't see the focusrite in the KDE audio device configs, etc.)

If I quit qjackctl and kill the jack server, then the system audio GUI sees the interface and can use it, play audio, etc., everything works.

Mostly this is fine -- I'm happy to remove a layer of complexity from my setup -- but occasionally I do use jack for some strange routing/loopback/etc stuff and I'd like to understand why pipewire apparently can't see the jack hooks for system playback.

I installed pipewire-jack on a whim, but it didn't help -- anything I need to do to get this going?

Thanks!

[Bings]

I don't use pipewire, so can't answer you expertly but I know the creator of qjackctl made qpwgraph to replace the qjackctl graph for pipewire. I checked and it comes with 22.10 so you should be able to: sudo apt install qpwgraph

AFAIK, pipewire-jack acts as the jack server for your jack programs to connect too so you shouldn't start one with qjackctl

[chconnor]

Thanks! Good to know about qpwgraph. Unfortunately I use Reaper in linux and it uses jack to talk to the device; I tried switching to pulseaudio in reaper and it shows up in qpwgraph but the number of channels is wrong with no obvious way to remedy... so for now I have a script starting reaper that starts up jack, etc. A pain, but at least I can get it working again.

[Bings]

Don't start up jack with a command, remove that from your script. Pipewire replaces jack and uses pipewire-jack to connect to jack programs. Try starting reaper normally without a script and without trying to start jack. See if it shows in qpwgraph. If not try starting Reaper from a terminal with the prefix pw-jack Reference: https://docs.pipewire.org/page_man_pw_jack_1.html

That's all I could find when having a look around. The Reaper forum does have a Linux section, so if what I suggest doesn't work, you could ask there and hopefully get help from someone with pipewire experience. Also the forum at linuxmusicians.com is very good.

[chconnor]

Hey yeah using the "pw-jack" prefix did the trick! (Running without, Reaper did not show up in the graph.) Thanks for that. So far it seems great.

Last thing is I needed control over the sample buffer size and the sample rate, and it seems this is the only way (which is fine; I just add it to the top of my reaper script):

pw-metadata -n settings 0 clock.force-rate 44100
pw-metadata -n settings 0 clock.force-quantum 256​

more here: https://gitlab.freedesktop.org/pipew.../-/issues/2077