No MIDI inputs with JACK running on Linux

loopier

Hi,

I'm trying to build an app with Godot that receives MIDI from other applications. I was expecting to use JACK, as I need it to be running for some of the software I will be using. Unfortunately, OS.get_connected_midi_inputs() only lists devices when JACK is not running, and it only lists hardware devices. I do have ALSA bridge running, and have never had any problems with it. Is JACK not suported by Godot?

Calinou

Is JACK not suported by Godot?

Godot has native ALSA and PulseAudio drivers, but no JACK driver. It defaults to PulseAudio, so you have to start a Godot project with the --audio-driver ALSA command line argument to make it use ALSA instead.

See this proposal for adding a JACK driver to Godot.

loopier

By running godot --audio-driver ALSA from the command line in the directory of the project, the project runs but software devices are still not listed (cannot try with a hardware device right now). It logs that the device is busy:

ALSA lib rawmidi_hw.c:235:(snd_rawmidi_hw_open) open /dev/snd/midiC1D0 failed: Device or resource busy
MIDI devices: [] // this is the output of print("MIDI devices: ",OS.get_connected_midi_inputs())

loopier

I tried with a MIDI hardware device, and I get still the same behavior, no devices listed with JACK running, and just hardware is listed with JACK stopped.

When I start Godot with --audio-driver ALSA I would expect it to be available as input in ALSA, but it's not listed either with amidi -l which lists only hardware, or aconnect -l which lists both hardware and software.

$ aconnect -l
client 0: 'System' [type=kernel]
    0 'Timer           '
    1 'Announce        '
client 14: 'Midi Through' [type=kernel]
    0 'Midi Through Port-0'
client 20: 'UMA25S' [type=kernel,card=1]
    0 'UMA25S MIDI 1   '
client 28: 'UMC404HD 192k' [type=kernel,card=3]
    0 'UMC404HD 192k MIDI 1'
client 128: 'SuperCollider' [type=user,pid=18939]
    0 'in0             '
    1 'in1             '
    2 'in2             '
    3 'in3             '
    4 'in4             '
    5 'out0            '
    6 'out1            '
    7 'out2            '