Frequency domain output of the FFT block seems to be mirrored when using floating point data type. I recall that when using complex numbers this mirroring doesn't occur. The input I'm working with is 48khz sound from a wav file. I understand this mirroring is a characteristic of the Fourier transform, but what I'm wondering is what is the best way to recover the useful information from the FFT when using floating point numbers. Put another way, is it safe to discard the left side of the output as it appears to consist only of aliases of the true data? Are there any better ways to do this?
I tried marshaling the data into complex data before feeding it into the FFT but I couldn't get a reliable process.
If discarding half of the FFT output is the way to go then what about the wasted CPU in calculating that half of the frequency domain - is there a better way to recover the useful frequency domain information?
Thanks!