Re: IFFT to Wavetable ?


"Robert A." <invalid@xxxxxxxxxxx> wrote in message
news:WBT4g.168$UY5.152@xxxxxxxxxxx
Hi guys,

I'm trying to implement an algorithm where you fill in real and imaginary
arrays then do an Inverse FFT to convert them to a wavetable.

The code I'm basing it from is like this:

double real[4];
double imag[4];

// fill them in

double wavetable[8];

IFFT(real,imag,wavetable);

It's using an FFT library (in a DLL) so I don't know what's going on. The
thing I don't understand is how I get a real array of length 8 from a
complex array of length 4.
Spect you are getting 4 real values and 4 imag values returned - you want to
find how they are ordered ?

The FFT I use takes real and imag arrays and returns the result in the
same arrays, like this:

FFT(int dir, int n,double* real,double* imag);

...so how do I combine them to make the wavetable ? The wavetable is
supposed to be perfectly loop-able also.

Why not use some other freely available fft routine to generate some test
vectors and results then you can compare your outputs to find out what is
real/imaginary and how ordered?

Best of luck - Mike


.

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