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ttshaw1

Member

Registered: 2020-04-12

Posts: 38

Prevent ALSA MIDI connections in favor of Pipewire/JACK MIDI

I have a bash script that starts up Hydrogen, Yoshimi, Ardour, an editor for my guitar pedal, and qpwgraph with an activated patchbay file. In the patchbay file, I've saved the pipewire audio and pipewire/JACK MIDI connections that I want; any new audio sources and sinks that aren't covered by the patchbay file tend to be added sanely when the need arises. The problem is the legacy ALSA MIDI stuff. There are MIDI connections that I absolutely do not want, such as the guitar pedal's MIDI output going to Yoshimi, which causes a horrible shrieking when I try to program the pedal. There's no way to ban this connection in a qpwgraph patchbay file, and ALSA MIDI seems to make connections like that according to its own whims. Or possibly one of the programs I'm running is trying to make that connection.

But the point is that the pipewire/JACK MIDI system works fine and accomplishes the same thing without any problems, so I want to take the ALSA MIDI system out of the picture. How can I do that? My mental picture is that the audio stack is kind of a house of cards, with ALSA as the base, Pulse on top of that, and JACK and pipewire on top of Pulse with pipewire also resting on JACK; so I don't want to go blindly ripping out ALSA for fear of collapsing the whole thing. Is there a kernel module I should try to blacklist, for example?

ttshaw1

Member

Registered: 2020-04-12

Posts: 38

Re: Prevent ALSA MIDI connections in favor of Pipewire/JACK MIDI

This may be a problem of me not understanding the system well enough. I found that I could switch Hydrogen to a Pipewire/JACK MIDI engine in Preferences/MIDI System/MIDI Driver, and do the same in Yoshimi by setting Settings/Alsa/Alsa Connection Type to Fixed, unchecking "Set as preferred MIDI", and checking "Set as preferred MIDI" in the Jack tab. Both programs' ALSA MIDI boxes disappeared from qpwgraph, the relevant sink/source in the PW/JACK MIDI Bridge disappeared, and a new box for each program popped up with a PW/JACK input.

If I can figure out how to do something similar in Firefox for Web MIDI I'll have achieved my goal. I'm not sure that's possible, though.

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 23,447

Re: Prevent ALSA MIDI connections in favor of Pipewire/JACK MIDI

What output do you have from

aplaymidi -l

? If nothing listens to 128 here you might have to get a dummy route going. And googling a bit further https://gitlab.freedesktop.org/pipewire … ssues/2684 pipewire doesn't directly support taking this over, but you might be able to coerce something with the snd_virmidi module