[PlanetCCRMA] How to build MIDI intercept code?

[Fernando Lopez-Lezcano]

On Wed, 2005-07-06 at 05:40, Steve Harris wrote:
> On Wed, Jul 06, 2005 at 01:13:01 +0100, Charles Fox wrote:
> > > I'd like to build the software equivilent of a MIDI intercept box, which 
> > sits on the MIDI wire, and changes the signals on the wire.
> > 
> > For example:
> >    1) a black box with a transpose control on it, that transposes the 
> > pitch of the events on the wire
> >    2) a velocity controller, that alters the vecloity params of note on 
> > and off events to match some external input.
> > 
> > What's the best way to structure this kind of project?  Should I write a 
> > JACK device so I can route my midi wires to and from it?  Is that too much 
> > work?  I am new to linux audio so please be gentle :)
> 
> MIDI over JACK is still pretty new, and I'm not sure how well supported it
> is. Better options might be to write an alsa-sequencer app
> (http://www.alsa-project.org/~frank/alsa-sequencer/) or if you like high
> level stuff, do it in PD (http://www.puredata.info/). PD was built for
> this kind of task.

Pd will do, or if you really want to write your own program you can get
"inspiration" from the likes of qmidiroute, qmidicontrol and/or
qmidiarp. All simple ALSA sequencer applications. 

-- Fernando