I have seen audio visualization done before…does anyone know of good tutorials out there or starting places on making such programs? thanks.
Why not have a look at the WINAMP viz stuff.
There’s info and sdk etc to help you write such things.
In many cases though you usually start off with a spectral analysis (using fft), get the power in frequency “bands” (you decide how fine these bands might be).
You then use this power data to control aspects of the “visualisation”.
e.g. you have a set of quads for each band, the intensity of their colours is controlled by the power in the band, in real time. The usual one of course is like a histogram, and the height of the bar is controlled by the power (i.e. a real time graph of the power spectrum!).
but, if you want to get “arty farty”, then of course you can use lots of different aspects of the data to control other things …
e.g. the power of the high frequencies can say control the brightness of your OpenGL lights … maybe control movement, blending, speed of colour transitions and so on.
Don’t be afraid to use 2nd order effects and so on.
The viz is only as good as your imagination!
Play with WINAMP viz, and you can get the idea.