Implementing FFT

[vineet.jain]

hi how can i implement FFT analysis for a recorded audio file?.I have implemented the FFT algo given in wiki, but what to do next i have no idea.

[mayankkedia]

Well and what did you have in mind to achieve with the implementation of FTT though? For a simple usage of FFT(generic not on Symbian), check this :-

http://www.mts.net/~mathers/q1_fft.html

[kamalakshan]

hi how can i implement FFT analysis for a recorded audio file?.I have implemented the FFT algo given in wiki, but what to do next i have no idea.

What exactly do you want to achieve?

[vineet.jain]

actually i want to implement FFT on an audio signal for the analysis of various sound variations in an audio file.For e.g if in a recorded audio file i have some silence and some voice, then i want to differentiate between the two by measuring its intensity graphically , i mean to measure the variations of different sounds in a particular audio file, so i was just wandering if FFT would be a better way to do it, but im not getting any idea on how to implement it in symbian.

[wizard_hu_]

FFT and signal processing in general have nothing Symbian-specific in it. You either know what it is, or you should simply read and learn.
Fourier transformation is particularly useful when you are interested in characteristic frequencies of a given audio sample. However for differentiating between "sound" and "silence" it would be simpler to rely on the energy content of the audio data. Calculate (root) mean-square over a sliding window, and specify some threshold via experimentation.