ifft.h

/*
 * Copyright (c) 2008, Swedish Institute of Computer Science
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 * -----------------------------------------------------------------
 * ifft - Integer FFT (fast fourier transform) library
 *
 *
 *
 * Author  : Joakim Eriksson
 * Created : 2008-03-27
 * Updated : $Date: 2008/04/25 22:12:25 $
 *           $Revision: 1.2 $
 */
 
#ifndef IFFT_H
#define IFFT_H
#include "contiki.h"
 
/* ifft(xre[], n) - integer (fixpoint) version of Fast Fourier Transform
   An integer version of FFT that takes in-samples in an int16_t array
   and does an fft on n samples in the array.
   The result of the FFT is stored in the same array as the samples
   was stored.
 
   Note: This fft is designed to be used with 8 bit values (e.g. not
   16 bit values). The reason for the int16_t array is for keeping some
   'room' for the calculations. It is also designed for doing fairly small
   FFT:s since to large sample arrays might cause it to overflow during
   calculations.
*/
void ifft(int16_t xre[], int16_t xim[], uint16_t n);
 
#endif /* IFFT_H */