[linux-audio-user] on ALSA's virmidi module

[Clemens Ladisch]

Frank Barknecht wrote:
> Dave Phillips hat gesagt: // Dave Phillips wrote:
> >        export ALSA_RAWMIDI_DEVICE=hw:1,0
>
> Cool. But I find it a bit strange, that Keyit uses the PCM definition
> for midi access.

This isn't a PCM definition, it's a RawMIDI definition (which happens
to have the same name). All ALSA devices implemented in the kernel are
accessed by a plugin named "hw". See /usr/share/alsa/conf/alsa.conf
for the various definitions (pcm, ctl, rawmidi, seq, hwdep, timer).

It's possible to give some rawmidi port its own name, just like pcms:

	rawmidi.my_virtual {
		type hw
		card 1
		device 0
	}

then you could use my_virtual instead of hw:1,0.


Another useful plugin (the only other currently available
rawmidi plugin) is the virtual rawmidi device, which is implemented in
user space and doesn't need the snd-virmidi kernel driver.

If you use "virtual" instead of "hw:1,0", each application using this
will create a virtual sequencer port on the fly. (This may not be what
you want, because each application instance will create a seperate
virtual device, and the port exists only as long as the application is
running).


HTH
Clemens