what are input value given for finding the length of data of .wav file in phone

[warrior]

I am trying to read the .wav file and give the raw data as input to the FFT algorithm.I am trying to implement OouraFFT.In the the "Read Me" doc it has given to create instance of OouraFFT class.

// 1. First initialize the class
OouraFFT *myFFT = [[OouraFFT alloc] initForSignalsOfLength:numFrequencies*2 andNumWindows:kNumFFTWindows];

I am having only the audio file(.wav),i dont know about the two parameters passed "numFrequencies" and "kNumFFTWindows".what are these values.How can i get this from the available audio file(.wav).Should i give any static values to it.If so what are they?.Thanks.