Audio analyzer library

[Raphael]

This is my audio analyzer library that I used for Funky Demo to do the beat detection and equalizer. It's not a perfect solution but rather an approximation, but it is fast and flexible. Original code was posted by memon on ps2dev.org, which I took as base and added some features and optimized.

Usage is pretty simple:
- Initialize the analyzer at startup with the number of subbands you want (normally 16 - 32).
- In your music playback code (audio callback), feed the analyzer with the left and right samples through the au_analyzer_feed() function.
- In your mainloop you call au_analyzer_update() every frame and then use the several au_analyzer_get* functions to get information which you can then visualize.

Play around if you like, there's a lot possible with this.

[Ryalla]

Very nice stuff. That "beat detection" sounds interesting..

[A_Nub]

so this could be used for a visualizer right?
Like take the beat detection and equalizer and have them post up updating variables that control different visual effects or am i confused as to what this does? Is it like a metronome to detect the tempo?

[Raphael]

Yes, it's basically a visualization data engine for a demo, but could be used for a music player as well. It's not perfectly accurate (esp the beat detection with fast music), but therefore its also pretty fast. I'm still thinking about a more accurate implementation with a FFT to get accurate beat detection and frequency bands.