ref: 6391fe82298c5ff673e0249a2b48f2f9fef51ecd
dir: /tests/dft-test.c/
#ifdef HAVE_CONFIG_H #include "config.h" #endif #include <stdio.h> #include "kiss_fft.h" #include "../libcelt/kiss_fft.c" #ifndef M_PI #define M_PI 3.141592653 #endif int ret = 0; void check(kiss_fft_cpx * in,kiss_fft_cpx * out,int nfft,int isinverse) { int bin,k; double errpow=0,sigpow=0, snr; for (bin=0;bin<nfft;++bin) { double ansr = 0; double ansi = 0; double difr; double difi; for (k=0;k<nfft;++k) { double phase = -2*M_PI*bin*k/nfft; double re = cos(phase); double im = sin(phase); if (isinverse) im = -im; if (!isinverse) { re /= nfft; im /= nfft; } ansr += in[k].r * re - in[k].i * im; ansi += in[k].r * im + in[k].i * re; } /*printf ("%d %d ", (int)ansr, (int)ansi);*/ difr = ansr - out[bin].r; difi = ansi - out[bin].i; errpow += difr*difr + difi*difi; sigpow += ansr*ansr+ansi*ansi; } snr = 10*log10(sigpow/errpow); printf("nfft=%d inverse=%d,snr = %f\n",nfft,isinverse,snr ); if (snr<60) { printf( "** poor snr: %f ** \n", snr); ret = 1; } } void test1d(int nfft,int isinverse) { size_t buflen = sizeof(kiss_fft_cpx)*nfft; kiss_fft_cpx * in = (kiss_fft_cpx*)malloc(buflen); kiss_fft_cpx * out= (kiss_fft_cpx*)malloc(buflen); kiss_fft_cfg cfg = kiss_fft_alloc(nfft,0,0); int k; for (k=0;k<nfft;++k) { in[k].r = (rand() % 32767) - 16384; in[k].i = (rand() % 32767) - 16384; } #ifdef DOUBLE_PRECISION for (k=0;k<nfft;++k) { in[k].r *= 32768; in[k].i *= 32768; } #endif if (isinverse) { for (k=0;k<nfft;++k) { in[k].r /= nfft; in[k].i /= nfft; } } /*for (k=0;k<nfft;++k) printf("%d %d ", in[k].r, in[k].i);printf("\n");*/ if (isinverse) kiss_ifft(cfg,in,out); else kiss_fft(cfg,in,out); /*for (k=0;k<nfft;++k) printf("%d %d ", out[k].r, out[k].i);printf("\n");*/ check(in,out,nfft,isinverse); free(in); free(out); free(cfg); } int main(int argc,char ** argv) { if (argc>1) { int k; for (k=1;k<argc;++k) { test1d(atoi(argv[k]),0); test1d(atoi(argv[k]),1); } }else{ test1d(32,0); test1d(32,1); test1d(128,0); test1d(128,1); test1d(256,0); test1d(256,1); #ifndef RADIX_TWO_ONLY test1d(36,0); test1d(36,1); test1d(50,0); test1d(50,1); test1d(120,0); test1d(120,1); test1d(105,0); test1d(105,1); #endif } return ret; }