c@174: #include "kiss_fftr.h"
c@174: #include "_kiss_fft_guts.h"
c@174: #include <sys/times.h>
c@174: #include <time.h>
c@174: #include <unistd.h>
c@174: 
c@174: static double cputime(void)
c@174: {
c@174:     struct tms t;
c@174:     times(&t);
c@174:     return (double)(t.tms_utime + t.tms_stime)/  sysconf(_SC_CLK_TCK) ;
c@174: }
c@174: 
c@174: static
c@174: kiss_fft_scalar rand_scalar(void) 
c@174: {
c@174: #ifdef USE_SIMD
c@174:     return _mm_set1_ps(rand()-RAND_MAX/2);
c@174: #else
c@174:     kiss_fft_scalar s = (kiss_fft_scalar)(rand() -RAND_MAX/2);
c@174:     return s/2;
c@174: #endif
c@174: }
c@174: 
c@174: static
c@174: double snr_compare( kiss_fft_cpx * vec1,kiss_fft_cpx * vec2, int n)
c@174: {
c@174:     int k;
c@174:     double sigpow=1e-10,noisepow=1e-10,err,snr,scale=0;
c@174: 
c@174: #ifdef USE_SIMD
c@174:     float *fv1 = (float*)vec1;
c@174:     float *fv2 = (float*)vec2;
c@174:     for (k=0;k<8*n;++k) {
c@174:         sigpow += *fv1 * *fv1;
c@174:         err = *fv1 - *fv2;
c@174:         noisepow += err*err;
c@174:         ++fv1;
c@174:         ++fv2;
c@174:     }
c@174: #else
c@174:     for (k=0;k<n;++k) {
c@174:         sigpow += (double)vec1[k].r * (double)vec1[k].r + 
c@174:                   (double)vec1[k].i * (double)vec1[k].i;
c@174:         err = (double)vec1[k].r - (double)vec2[k].r;
c@174:         noisepow += err * err;
c@174:         err = (double)vec1[k].i - (double)vec2[k].i;
c@174:         noisepow += err * err;
c@174: 
c@174:         if (vec1[k].r)
c@174:             scale +=(double) vec2[k].r / (double)vec1[k].r;
c@174:     }
c@174: #endif    
c@174:     snr = 10*log10( sigpow / noisepow );
c@174:     scale /= n;
c@174:     if (snr<10) {
c@174:         printf( "\npoor snr, try a scaling factor %f\n" , scale );
c@174:         exit(1);
c@174:     }
c@174:     return snr;
c@174: }
c@174: 
c@174: #ifndef NUMFFTS
c@174: #define NUMFFTS 10000
c@174: #endif
c@174: 
c@174: 
c@174: int main(int argc,char ** argv)
c@174: {
c@174:     int nfft = 8*3*5;
c@174:     double ts,tfft,trfft;
c@174:     int i;
c@174:     if (argc>1)
c@174:         nfft = atoi(argv[1]);
c@174:     kiss_fft_cpx cin[nfft];
c@174:     kiss_fft_cpx cout[nfft];
c@174:     kiss_fft_cpx sout[nfft];
c@174:     kiss_fft_cfg  kiss_fft_state;
c@174:     kiss_fftr_cfg  kiss_fftr_state;
c@174: 
c@174:     kiss_fft_scalar rin[nfft+2];
c@174:     kiss_fft_scalar rout[nfft+2];
c@174:     kiss_fft_scalar zero;
c@174:     memset(&zero,0,sizeof(zero) ); // ugly way of setting short,int,float,double, or __m128 to zero
c@174: 
c@174:     srand(time(0));
c@174: 
c@174:     for (i=0;i<nfft;++i) {
c@174:         rin[i] = rand_scalar();
c@174:         cin[i].r = rin[i];
c@174:         cin[i].i = zero;
c@174:     }
c@174: 
c@174:     kiss_fft_state = kiss_fft_alloc(nfft,0,0,0);
c@174:     kiss_fftr_state = kiss_fftr_alloc(nfft,0,0,0);
c@174:     kiss_fft(kiss_fft_state,cin,cout);
c@174:     kiss_fftr(kiss_fftr_state,rin,sout);
c@174:     /*
c@174:     printf(" results from kiss_fft : (%f,%f), (%f,%f), (%f,%f) ...\n "
c@174:             , (float)cout[0].r , (float)cout[0].i
c@174:             , (float)cout[1].r , (float)cout[1].i
c@174:             , (float)cout[2].r , (float)cout[2].i); 
c@174:     printf(" results from kiss_fftr: (%f,%f), (%f,%f), (%f,%f) ...\n "
c@174:             , (float)sout[0].r , (float)sout[0].i
c@174:             , (float)sout[1].r , (float)sout[1].i
c@174:             , (float)sout[2].r , (float)sout[2].i); 
c@174:     */
c@174:         
c@174:     printf( "nfft=%d, inverse=%d, snr=%g\n",
c@174:             nfft,0, snr_compare(cout,sout,(nfft/2)+1) );
c@174:     ts = cputime();
c@174:     for (i=0;i<NUMFFTS;++i) {
c@174:         kiss_fft(kiss_fft_state,cin,cout);
c@174:     }
c@174:     tfft = cputime() - ts;
c@174:     
c@174:     ts = cputime();
c@174:     for (i=0;i<NUMFFTS;++i) {
c@174:         kiss_fftr( kiss_fftr_state, rin, cout );
c@174:         /* kiss_fftri(kiss_fftr_state,cout,rin); */
c@174:     }
c@174:     trfft = cputime() - ts;
c@174: 
c@174:     printf("%d complex ffts took %gs, real took %gs\n",NUMFFTS,tfft,trfft);
c@174: 
c@174:     free(kiss_fft_state);
c@174:     free(kiss_fftr_state);
c@174: 
c@174:     kiss_fft_state = kiss_fft_alloc(nfft,1,0,0);
c@174:     kiss_fftr_state = kiss_fftr_alloc(nfft,1,0,0);
c@174: 
c@174:     memset(cin,0,sizeof(cin));
c@174: #if 1
c@174:     for (i=1;i< nfft/2;++i) {
c@174:         //cin[i].r = (kiss_fft_scalar)(rand()-RAND_MAX/2);
c@174:         cin[i].r = rand_scalar();
c@174:         cin[i].i = rand_scalar();
c@174:     }
c@174: #else
c@174:     cin[0].r = 12000;
c@174:     cin[3].r = 12000;
c@174:     cin[nfft/2].r = 12000;
c@174: #endif
c@174: 
c@174:     // conjugate symmetry of real signal 
c@174:     for (i=1;i< nfft/2;++i) {
c@174:         cin[nfft-i].r = cin[i].r;
c@174:         cin[nfft-i].i = - cin[i].i;
c@174:     }
c@174: 
c@174:     kiss_fft(kiss_fft_state,cin,cout);
c@174:     kiss_fftri(kiss_fftr_state,cin,rout);
c@174:     /*
c@174:     printf(" results from inverse kiss_fft : (%f,%f), (%f,%f), (%f,%f), (%f,%f), (%f,%f) ...\n "
c@174:             , (float)cout[0].r , (float)cout[0].i , (float)cout[1].r , (float)cout[1].i , (float)cout[2].r , (float)cout[2].i , (float)cout[3].r , (float)cout[3].i , (float)cout[4].r , (float)cout[4].i
c@174:             ); 
c@174: 
c@174:     printf(" results from inverse kiss_fftr: %f,%f,%f,%f,%f ... \n"
c@174:             ,(float)rout[0] ,(float)rout[1] ,(float)rout[2] ,(float)rout[3] ,(float)rout[4]);
c@174: */
c@174:     for (i=0;i<nfft;++i) {
c@174:         sout[i].r = rout[i];
c@174:         sout[i].i = zero;
c@174:     }
c@174: 
c@174:     printf( "nfft=%d, inverse=%d, snr=%g\n",
c@174:             nfft,1, snr_compare(cout,sout,nfft/2) );
c@174:     free(kiss_fft_state);
c@174:     free(kiss_fftr_state);
c@174: 
c@174:     return 0;
c@174: }