[linux-audio-dev] OSC vs MIDI

[Dave Robillard]

On Fri, 2004-09-03 at 18:07, Steve Harris wrote:
> On Thu, Sep 02, 2004 at 11:53:37 -0400, Dave Robillard wrote:
> > > Funny you should say that... I'm hoping to find time to add the propsed
> > > rec. for OSC service exploration/enumeration to liblo (not discovery,
> > > thats a seperate problem) that would allow (limited) generic OSC clients
> > > that coul list hte parameters of an OSC service, and witha bit of extra
> > > code in the OSC servers will allow you draw sliders and so on.
> > 
> > What do you mean by "limited", and why would drawing sliders require
> > extra code in the OSC servers?
> 
> The liblo API doesnt not currently have any way to specify what the ranges
> on the parameters are, so the library cant report it, so you cant make
> (useful) sliders.
>  
> > Maybe I misunderstand you (likely), but it sounds like maybe a little
> > too much specific stuff in liblo to me, which I know you're against. 
> > Doesn't service discovery and a standard for how to query parameters
> > solve this problem?  (ie client discovers a new server, sends
> > "/send_params MY_ADDR", and gets all the information in a
> > standard-defined way).
> 
> Service discovery just covers being able to locate liblo servers, you need
> some other stuff to actually find out what the controls are. The other
> stuff is heading towards standardisation, but hte service discovery isn't
> - the zeroconf inplementation would be fairly obvious though.
>  
> > Basically, I don't see what needs to be done to liblo, other than the
> > service discovery part.
> 
> Nothing, but the API doesnt include enough stuff yet. I dont really want
> to expand the API until its standardised properly though.

My point was that ranges for controls and stuff like that probably don't
really belong in the liblo API at all.. I would expect you, wanting to
keep liblo simple, would agree on that.

Wouldn't just a standard that defines how OSC apps can tell each other
about their controls (and ranges, and all that) be much nicer?  Things
like this depending on liblo is probably a bad idea IMO.

Something like:

/foo/define_control "volume" MIN MAX

or whatever.. then the service discovery is all liblo needs to bother
with, and apps can talk to each other following this hypothetical RFC.

Then again, maybe if it WAS in liblo, there wouldn't be problems with
changing the RFC, and breaking old clients, and all that nasty stuff. 
Hmm.

Thoughts?

-DR-