Mixxx currently uses the PortMIDI to communicate with devices. On Linux, it uses ALSA's MIDI subsystem which offers the virtual port. Have you tried using JACK's MIDI capabilities? That should expose more software ports for Mixxx to use any way you like.
Mixxx currently uses the PortMIDI to communicate with devices. On Linux, it uses ALSA's MIDI subsystem which offers the virtual port. Have you tried using JACK's MIDI capabilities? That should expose more software ports for Mixxx to use any way you like.