[LAU] Merging Midi with "VAST Programmer" and controller keyboard

Clemens Ladisch clemens at ladisch.de
Mon Jan 26 12:05:27 UTC 2015

Iain Mott wrote:
> When VP starts for the first time it asks the user to select from a list
> of available MIDI in and outs. I selected the HDSP which is displayed as
> "DSP [hw:0,0,0]".

This is a "raw MIDI" port, which is what the hardware drivers implement.
Application ports and merging are implemented in the ALSA sequencer on
top of that.

> VP does not show up in qjackctl however and once connected to the HDSP
> I can no longer make a connection between the UMX490 (readable client)
> and the Hammerfall DSO (writable client) in order to play the synth.
> The HDSP seems to be fully occupied.

When a program uses raw MIDI directly, these features are not available.

As a workaround, load the snd-virmidi kernel module, which creates
virtual raw MIDI ports that are then available as sequencer ports.
Connect VP to that, and then connect snd-virmidi's equivalent sequencer
port to the actual device.


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