Get Hz frequency from audio stream on iPhone

Question

What would be the best way to get Hz frequency value from audio stream(music) on iOS? What are the best and easiest frameworks provided by Apple to do that. Thanks in advanc

Answer 1

Apple does not provide a framework for frequency or pitch estimation. However, the iOS Accelerate framework does include routines for FFT and autocorrelation which can be used as components of more sophisticated frequency and pitch recognition or estimation algorithms.

There is no way that is both easy and best, except possibly for a single long continuous constant frequency pure sinusoidal tone in almost zero noise, where an interpolated magnitude peak of a long windowed FFT might be suitable. For voice and music, that simple method will very often not work at all. But a search for pitch detection or estimation methods will turn up lots of research papers on more suitable algorithms.