[PD] Using GEM for a music visualizer

Derek Holzer derek at umatic.nl
Sun Jan 13 14:18:59 CET 2008

Hi Ross,

Running GEM and PD for audio in the same instance isn't such a good 
idea. Better to keep the threads separate. Normally, if I want to use 
both together I run two different instances of PD, and communicate 
between them with OSC. One for the GEM and one for the audio. On OSX, 
you may have to start each PD instance from the command line:

/Applications/Pd-extended.app/Contents/Resources/bin/pd --noaudio --open 
<GEM patch>

/Applications/Pd-extended.app/Contents/Resources/bin/pd --nogui --open 
<audio patch>

should do the trick for with PD-extended. You could use the --nogui if 
all the controls are in the GEM patch. You could even make a shell 
script which opens both instances at once, with their respective patches.


Ross Mulcahy wrote:
> Hey all,
> I am trying to use GEM (on OSX), in particular pix_kaleidoscope, to 
> manipulate an image in real time based on a wav file currently playing 
> from an array. It is meant to be a very basic visualizer which needs to 
> be "wound up", i.e. periodically the music runs out like a wind up music 
> box and the user must rotate the mouse around the screen and click the 
> screen for the visualizer to continue!
> OK now here is the problem when i call pix_kaleidoscope and it starts 
> manipulating the image it starts using up 50% of my processor and the 
> music gets all jumpy and the image changes are not smooth at all. Is 
> there a way around this or a simpler, less processor hungry, method of 
> manipulating the image for the same visual effect?

derek holzer ::: http://www.umatic.nl ::: http://blog.myspace.com/macumbista
---Oblique Strategy # 202:
"Back up a few steps.
What else could you have done?"

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