iPhone SDK measure frequency over iphone mic

Question

Hello,

I need a way to get the inout from the microphone and determine the the average frequency. Is there a library or something to handle this?

Thanks

Answer 1

You'll want to use an FFT, so I'd recommend looking at this Q&A:

http://stackoverflow.com/questions/1592345/do-you-know-a-good-and-efficient-fft

Answer 2

If you're targeting iOS 4 and above, Apple now includes the Accelerate framework. From Apple's "What's new" page:

http://developer.apple.com/technologies/iphone/whats-new.html#api

Accelerate

Accelerate provides hundreds of mathematical functions optimized for iPhone and iPod touch, including signal-processing routines, fast Fourier transforms, basic vector and matrix operations, and industry-standard functions for factoring matrices and solving systems of linear equations.