this is my first crack at a beat detection algorithm in flash. it works by calculating average sample energy per frame over a certain band and compares the value against the last few values stored in a buffer. if the value is larger then whats in the memory, a beat occurs. currently it supports multiple bands, so you can listen for a kick or a snare at the same time. the theory is based on this article that i found while looking at some processing examples.
ive knocked up a little example, left and right arrow keys moves the band across the spectrum, < and > keys stretch and shrink the band, up and down arrow keys increase and decrease the beat threshold. you will see two line markers jumping around, the white represents the average energy for the current frame within that band and the yellow represents the average energy in the buffer.
check out the swf here. download the source here.
Hot damn! That works pretty well, I do say! Let’s see if I can make something pretty with it…
Hey man, I liked this so much that I used it as a base for the bumping speakers on 5354.biz. Nice work. :)
Hey dude, you are the first one I found who got this working well! Big up!
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Waouww !! it’s verry good base for me.. :D i seach for making a beat detctor class in AS3. After, i like to implement this in C or C++ with Adobe Alchemy.. But your work is verry nice for immediate time.. :D
Checking it out man, thx!
[...] http://www.julapy.com/blog/2007/12/30/beat-detection-in-flash/ http://blog.andrevenancio.com/2010/01/06/beat-detection/ http://xobert.com/beatdetector/ [...]
[...] l’algorithme de détection du tempo, je me suis basé sur une source Flash très efficace: beat detection in flash. Le principe est le suivant: on calcule l’énergie instantanée par frame en faisant la [...]