12 Real optimized version can save about 45% cpu time vs. complex fft of a real seq.
18 typedef struct kiss_fftr_state *kiss_fftr_cfg;
21 kiss_fftr_cfg kiss_fftr_alloc(int nfft,int inverse_fft,void * mem, size_t * lenmem);
25 If you don't care to allocate space, use mem = lenmem = NULL
29 void kiss_fftr(kiss_fftr_cfg cfg,const kiss_fft_scalar *timedata,kiss_fft_cpx *freqdata);
31 input timedata has nfft scalar points
32 output freqdata has nfft/2+1 complex points
35 void kiss_fftri(kiss_fftr_cfg cfg,const kiss_fft_cpx *freqdata,kiss_fft_scalar *timedata);
37 input freqdata has nfft/2+1 complex points
38 output timedata has nfft scalar points
41 #define kiss_fftr_free free