Audio frequency and amplitude

Question

I need to record audio from iPhone. During recording I need to know, how many audio waves I have at the current moment and frequency and amplitude of each wave. It seems to me, that avaudiorecorder can't help me.

I had a look at Apple's SpeakHere sample code, but I can get only amplitude from here (as I understand).

I had a look at Apple's aurioTouch sample code. It seems, that it does, what I need, but sample code is incredibly big and written mostly in C++, so it's difficult for me to understand it.

Can anybody give me examples, how to get Audio frequency and amplitude. It will be better, if you give me code examples.

Answer 1

Apple's aurioTouch sample app appears to be written using some C++ for absolutely no reason. Convert the code to plain C, and maybe you'll understand it better. Near real-time DSP audio analysis doesn't get much easier, so read up on that topic.