detecting sound tempo/beats

iOS
#1

Hi all,

I am trying to get information regarding the tempo of a playing music file on the iphone.

I looked first at ofSoundPlayer, and that looked promising, but of course it turns out that it is not yet ported to the iphone.

so I have added the ofxALSoundPlayer, and that is playing music fine, but doesn’t appear to have any way for me to query for information about the playing sound.

I really do not know much about this area, and I am very interested in some pointers on where to look…it feels as though I should be able to extend ofALSoundPlayer to take advantage of the OpenAL.framework to get this information, btu I dont have any idea how to get started.

does anyone have any suggestions?

thanks.

  • Andrew
#2

i would just look into the soundEngine.h/.cpp file and try and figure out what apple did in there. it’s a bit tricky and weird but you can definitely extend it with other openAL functions.

I would imagine that this will be a processor intensive process depending on how you do it though. It might be worthwhile to figure out a way to pre-analyize the sound data and cache the beat / tempo detection if thats possible for what you’re doing as the iphone doesnt have a ton of processing power

#3

i’d advocate pre-calculating as well. finding bpm is processor intensive and extremely difficult to do on your own.

try this: echo-nest (behind the awesome morecowbell.dj).