[LAU] snd-virmidi not working

[Pedro Lopez-Cabanillas]

Clemens Ladisch wrote:
> Crypto wrote:
> > I understand that the module snd-virmidi can be loaded via modprobe from
> > the command line. BUT: I cannot get it to work. The module does not pass
> > any data transferred to it.
> >
> > What am i doing wrong? I simply connected one MIDI output of things like
> > the vkeybd to the virtual MIDI port and then connected kmidimon to the
> > virtual port to see if something is happening. But nothing.
>
> snd-virmidi is used to make ALSA sequencer ports available as OSS MIDI
> ports, i.e., anything sent to the sequencer port can be read from the
> corresponding /dev/midi* device, and vice versa.
>

In addition to Clemens' explanation, I would say that kmidimon understands 
only ALSA sequencer ports. Including snd-virmidi ALSA sequencer outputs.  

On the other side, vkeybd can be enabled at compile time to use several MIDI 
systems, OSS among them (in Makefile, set USE_MIDI = 1). So you could use 
vkeybd to write events to an OSS MIDI device node, using a command line like 
this one:

$ vkeybd --device midi --mididev /dev/midiX 

And then read those events from the ALSA sequencer side of snd-virmidi using 
kmidimon. Are you doing exactly that? If so, then several things may go 
wrong: the MIDI node name not corresponding to the virmidi module, one or 
both programs not working properly, or even a bug in ALSA...

If you are using Ubuntu or Debian, please avoid kmidimon from the official 
repositories. It is an old and buggy release, that has been fixed one year 
ago! Please compile it from sources, version 0.5.1 or later. Thanks. 

Regards,
Pedro