DFT¶
- Author or source: Andy Mucho
- Type: fourier transform
- Created: 2002-01-17 01:59:38
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 | AnalyseWaveform(float *waveform, int framesize)
{
float aa[MaxPartials];
float bb[MaxPartials];
for(int i=0;i<partials;i++)
{
aa[i]=0;
bb[i]=0;
}
int hfs=framesize/2;
float pd=pi/hfs;
for (i=0;i<framesize;i++)
{
float w=waveform[i];
int im = i-hfs;
for(int h=0;h<partials;h++)
{
float th=(pd*(h+1))*im;
aa[h]+=w*cos(th);
bb[h]+=w*sin(th);
}
}
for (int h=0;h<partials;h++)
amp[h]= sqrt(aa[h]*aa[h]+bb[h]*bb[h])/hfs;
}
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