[linux-audio-dev] OSC vs MIDI

[Dave Griffiths]

On Tue, 31 Aug 2004 14:28:50 +0100, Steve Harris wrote
> On Tue, Aug 31, 2004 at 11:43:16AM +0100, Dave Griffiths wrote:
> > Hi all,
> > 
> > Ok, so I'm playing with osc (currently doing gui->app communication with it)
> > but all my individual apps still talk midi between them. This is quite
> > cumbersome, as I want to start having lots of controls that midi doesn't
> > support - and I don't really "think" in midi these days anyway.
> > 
> > Is there a case now to ditch midi support and go with osc for everything? I
> > see midi messages are a type within osc anyway - is it fairly straight forward
> > to be backwards compatible this way?
> 
> Yes, though the 'm' type is quite limited, its an address byte (MIDI 
> port number or something) and 3 bytes of MIDI-ness.
> 
> No good for SysEx or anything like that and you have to normalise running
> status. Good enough for notes, CC's and such though.

That's probably enough for me.

> The obvious problem you're likly to hit is that you still need to speak
> alsa-sequencer or something in order to get events from controllers. 
> You can go pure-OSC by accepting OSC 'm' types or occam format OSC messages
> and writing a simple, external and resuable MIDI->OSC converter.
> http://www.mat.ucsb.edu/~c.ramakr/illposed/occam.html

Might well have a go at this for hardware midi control. For OSC->MIDI though,
the only thing I might have a go at controlling that isn't my own software at
this point is supercollider, and that talks OSC anyway.

> BTW, if you have reasonable OSC covereage I'd be very interested in
> compatibility tests between whatever you're using and liblo.

Very early days, I've only implemented simple messages so far - but I'm using
liblo for my server and some python I've nicked for the client
http://cvs.sourceforge.net/viewcvs.py/pure-data/supercollider/python/OSC.py
Seems flawless so far though, and liblo's got a nice clean api.

cheers

dave