[OSC_dev] No dumpOSC output in pipe in non-interactive terminal

[Andy W. Schmeder]

On Sep 8, 2007, at 1:10 PM, Torsten Anders wrote:

> I want the OSC receiver care about realtime scheduling. Therefore,  
> I want to tell the OSC receiver that it should execute certain  
> bundles at some precise time point in future. I assumed that  
> timestamped bundles are intended for this purpose.

This is one of the originally intended uses for the OSC bundle time- 
tag, but the actual implementation of a realtime scheduler is beyond  
the scope of the OSC specification itself and also beyond the scope  
of a typical OSC encoder/decoder library.

Realtime scheduling is really in the domain of the operating system.   
Its not possible to make a library that implements it -- at best you  
can make a wrapper around the appropriate system calls.  A glance at  
the source code of an application such as PD or the Jack audio daemon  
should give a feel for the kind of attention to detail that is required.


> Why is full support for timestamped bundles not really necessary,  
> or what other way is there if I don't want to schedule events on  
> the side of the OSC sender? (I could do it in principle in my  
> language, but events may be irregularily delayed up to 20 msecs or  
> more due to the design of its realtime system).

An OSC encoder/decoder library does not have to understand or  
necessarily be able to manipulate the data that it is passing.  Its  
main function is to manage the parsing / state machine.  Some OSC  
libraries go a bit beyond this and get into so-called "dispatching"  
of the messages (i.e., typically, mapping addresses to function  
callbacks).  The dispatch feature may be attractive to some but I  
don't consider that to be essential either, and it certainly isn't  
the only design pattern that is effective for message handling.


---

Andy W. Schmeder
andy [at] cnmat.berkeley.edu
phone:	+1-510-643-9990 x.313
cell: 	+1-510-717-6653

Programmer/Analyst II
Center for New Music and Audio Technologies
University of California at Berkeley
http://cnmat.berkeley.edu




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