[Pd] Defeat real-time scheduling

[Mathieu Bouchard]

On Tue, 4 Apr 2006, Chuckk Hubbard wrote:

> Just a quick question... If I select this option, will it allow Pd to
> run like Csound?  I mean like, if I compose something but the synthesis
> method I want to use is too expensive to just play it, will a writesf~
> create a flawless audio file if "defeat real-time scheduling" is
> checked? -Chuckk

That's an unrelated option. There are two kinds (levels) of scheduling.  
There's the scheduling of the pd process by the OS kernel, and there's the
scheduling of pd objects by the pd process. IIRC "defeat real-time 
scheduling" is at the OS level.

If you have a patch that takes "250% of the CPU" or something like that, 
and it doesn't use the microphone/linein, and only writes to a file, then 
Pd should be able to do that flawlessly, if no objects use physical time, 
that is, they all use logical time instead. Logical time slows down when 
you use "more than 100% of the CPU" to account for the fact that only 100% 
of the CPU is usable (!) and it catches up on physical time when you allow 
it to.

What Pd currently can't do is the other way around, that is, force itself 
to use all of the CPU and accelerate logical time accordingly.

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| Mathieu Bouchard - tél:+1.514.383.3801 - http://artengine.ca/matju
| Freelance Digital Arts Engineer, Montréal QC Canada