liebrecht@grossmann-venter.com wrote:
Bitwig absolutely requires to have exclusive access to a USB pad Controller
ALSA has two MIDI APIs.
The low-level RawMIDI interface gives low-level access to the raw bytes going over a port, and usually allows only exclusive access.
The sequencer interface deals only on messages, allows user-space programs to create their own ports, and allows multiple connections per port. When a sequencer port corresponding to a hardware port is opened, the RawMIDI port is also opened and thus blocks other accesses.
Apparently, Bitwig uses the RawMIDI interface.
Try loading the snd-virmidi module (which creates a virtual sound card), and tell Bitwig to use that. You can then connect its sequencer ports to whatever hardware or software ports you like.
Regards, Clemens