How to extract frequency from 32-bit float array using FFT in c++

Question

I'm writing a small sound recognition program in C++. So I have an mp3 file which I sampled using mpg123 and got a 32-bit float array. Now I passed this array to FFT function and got some data. How do I extract frequencies?

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Alexey Birukov · Answer 1 · 2018-04-13T12:12:47.720

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"Some data" returned by FFT, must be a signal frequency spectrum. Probably it is an array of complex numbers, and to find "most powerful" frequency, you need to find an element with maximum absolute value (modulus). To calculate frequency, ... here was my mistake ... follow a link in Paul R's comment.

edited Apr 13 '18 at 12:12

answered Apr 12 '18 at 15:16

Alexey Birukov

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The last sentence regarding calculating frequency is not quite right: see [this explanation](https://stackoverflow.com/a/4371627/253056). – Paul R Apr 12 '18 at 16:05
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Oh, indeed, my bad. – Alexey Birukov Apr 13 '18 at 12:13

How to extract frequency from 32-bit float array using FFT in c++

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