JACK not letting me put MIDI from my inteface into software

[sagbobbit]

Hey, and I am continually sorry that forums on the web seem destined to be nothing more than IT support. But I have a problem, JACK seems to be working fine and completely recognizes my MIDI interface (Edirol UA-20), and my DAWs (Ardour and LMMS), but it colors the interface connections pink (even though it says "MIDI out") and the DAW connections red as though they aren't compatible, and indeed it doesn't allow me to hook them up to each other. Am I possibly doing something wrong in configuration or is there a way to force JACK to let me hook these up? Thanks so much.

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[LAM]

The answer is in your screenshot.

One says "ALSA" and one says "JACK".

You need something like a2jmidid to export the ALSA midi ports as JACK midi ports, or use a recent JACK2 and enable the SEQ ALSA sequencer in Qjackctl.

[Linuxmusician01]

(Spoiler alert: to make a long story short, can't you choose in LMMS's configure screen to use Alsa instead of Jack?)

Hmmmmm. So you don't see anything purple concerning LMMS? Not even when you press "Zoom fit" in the Graph from Qjackctl? I don't have LMMS installed so I can't check myself.

Anyway, if there's really no purple connection concerning LMMS then I'll have to explain some terms:

1. Alsa
2. Jack
3. Alsa-Midi
4. Jack-Midi
5. Alsa-to-jack midi bridge

Alsa is "the" audio driver for your hardware and it's what your (Linux) computer uses to produce sound. Jack is a "layer" on top of that. Don't ask why we Linuxers use Jack on top of Alsa for music production. PulseAudio is another one of those layers on top of Alsa. If you think that's a friggin' mess then you're right. They're about to be replaced by Pipewire.

Bost Alsa and Jack can "show" your Midi devices to your computer. You yourself can often choose in the setup screen of your DAW (digital audio workstation, like MMS) if you want to use Jack or simply only Alsa for audio. Sometimes you can't like in Qtractor: it'll only work with Jack.

Additionally, to make things even more confusing, your DAW chooses if it wants to use Jack-Midi or Alsa-Midi for you. Take for instance Reaper: it'll only work with Jack-Midi (and Qtractor only works with Alsa-Midi while it uses Jack for audio!). You can not choose. It looks like LMMS wants to use Jack-Midi, not Alsa-Midi.

Unfortunately audio hardware (the Edirol UA-20 in your case) is managed by Alsa and it always shows up as an Alsa-Midi device. Hence a piece of software to "bridge" Alsa-Midi to Jack-Midi (for DAW's that refuse to use Alsa-Midi). It's called a2jmidid and I start it like this:

Code: Select all

a2jmidid -e

Now for QJackctl's color coding:

• Green = Jack Audio
• Red = Jack Midi
• Purple = Alsa Midi

Example. Look at my Graph from QJackctl below. It's how I connect a Midi keyboard (Arturia Minilab) to Reaper (a DAW that uses Jack-Midi, not Alsa Midi)

If you look closely then you can see that a2jmidid bridged the Arturia Midi keyboard to Jack-Midi (it's in red). The Arturia shows up twice: once as an Alsa-Midi device and once as a Jack-Midi device. I connected the red Arturia keyboard to the red Reaper Jack-Midi in port. The green audio connections from System Jack-audio to Reaper Jack-audio are needed to record and/or playback audio from my sound-card (= audio device).

Good luck!

[sagbobbit]

Thanks so much for your verbose reply. a2jmidid did the trick nicely, LMMS can now receive MIDI input no issues. For anybody in the future reading this, I had to recompile the kernel with several CONFIG_SND_SEQ options changed from "m" to "y." In theory you could load those manually every time but now it all works nice at startup.

[scott.thomason]

... I had to recompile the kernel with several CONFIG_SND_SEQ options changed from "m" to "y." In theory you could load those manually every time but now it all works nice at startup.

I don't remember all the details offhand, but there's a file in /etc somewhere that allows you to "hint" to the kernel to load a module right away. Does anybody else recall the technique?

[ForrestH]

I don't remember all the details offhand, but there's a file in /etc somewhere that allows you to "hint" to the kernel to load a module right away. Does anybody else recall the technique?

/etc/modules-load.d/module-to-load.conf containing the module name may be what you want.