source: tests/src/test-fft.c @ 2d8880d5

#include <stdlib.h>
#include <math.h>
#include <complex.h>
#include <aubio.h>

#define NEW_ARRAY(_t,_n)                (_t*)malloc((_n)*sizeof(_t))


int main(){
        uint_t i,j;
        uint_t win_s      = 1024;                       // window size
        uint_t channels   = 1;                          // number of channel
        fvec_t * in       = new_fvec (win_s, channels); // input buffer
        cvec_t * fftgrain = new_cvec (win_s, channels); // fft norm and phase
        fvec_t * out      = new_fvec (win_s, channels); // output buffer
  
        // allocate fft and other memory space
        aubio_fft_t * fft      = new_aubio_fft(win_s);    // fft interface
        smpl_t * w             = NEW_ARRAY(smpl_t,win_s); // window
        // complex spectral data
        fft_data_t ** spec     = NEW_ARRAY(fft_data_t*,channels); 
        for (i=0; i < channels; i++)
                spec[i] = NEW_ARRAY(fft_data_t,win_s);
        // initialize the window (see mathutils.c)
        aubio_window(w,win_s,aubio_win_hanningz);
  
        // fill input with some data
        in->data[0][win_s/2] = 1;
  
        // execute stft
        for (i=0; i < channels; i++) {
                aubio_fft_do (fft,in->data[i],spec[i],win_s);
                // put norm and phase into fftgrain
                aubio_fft_getnorm(fftgrain->norm[i], spec[i], win_s/2+1);
                aubio_fft_getphas(fftgrain->phas[i], spec[i], win_s/2+1);
        }
  
        // execute inverse fourier transform
        for (i=0; i < channels; i++) {
                for (j=0; j<win_s/2+1; j++) {
                        spec[i][j]  = cexp(I*aubio_unwrap2pi(fftgrain->phas[i][j]));
                        spec[i][j] *= fftgrain->norm[i][j];
                }
                aubio_fft_rdo(fft,spec[i],out->data[i],win_s);
        }

        del_fvec(in);
        del_fvec(out);
        del_cvec(fftgrain);
        free(w);
        del_aubio_fft(fft);
        for (i=0; i < channels; i++)
                free(spec[i]);
        free(spec); 
        aubio_cleanup();
        return 0;
}