/* * (c) 2002 Fabrice Bellard * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * FFT and MDCT tests. */ #include "libavutil/mathematics.h" #include "libavutil/lfg.h" #include "libavutil/log.h" #include "fft.h" #if CONFIG_FFT_FLOAT #include "dct.h" #include "rdft.h" #endif #include <math.h> #include <unistd.h> #include <sys/time.h> #include <stdlib.h> #include <string.h> /* reference fft */ #define MUL16(a,b) ((a) * (b)) #define CMAC(pre, pim, are, aim, bre, bim) \ {\ pre += (MUL16(are, bre) - MUL16(aim, bim));\ pim += (MUL16(are, bim) + MUL16(bre, aim));\ } #if CONFIG_FFT_FLOAT # define RANGE 1.0 # define REF_SCALE(x, bits) (x) # define FMT "%10.6f" #else # define RANGE 16384 # define REF_SCALE(x, bits) ((x) / (1<<(bits))) # define FMT "%6d" #endif struct { float re, im; } *exptab; static void fft_ref_init(int nbits, int inverse) { int n, i; double c1, s1, alpha; n = 1 << nbits; exptab = av_malloc((n / 2) * sizeof(*exptab)); for (i = 0; i < (n/2); i++) { alpha = 2 * M_PI * (float)i / (float)n; c1 = cos(alpha); s1 = sin(alpha); if (!inverse) s1 = -s1; exptab[i].re = c1; exptab[i].im = s1; } } static void fft_ref(FFTComplex *tabr, FFTComplex *tab, int nbits) { int n, i, j, k, n2; double tmp_re, tmp_im, s, c; FFTComplex *q; n = 1 << nbits; n2 = n >> 1; for (i = 0; i < n; i++) { tmp_re = 0; tmp_im = 0; q = tab; for (j = 0; j < n; j++) { k = (i * j) & (n - 1); if (k >= n2) { c = -exptab[k - n2].re; s = -exptab[k - n2].im; } else { c = exptab[k].re; s = exptab[k].im; } CMAC(tmp_re, tmp_im, c, s, q->re, q->im); q++; } tabr[i].re = REF_SCALE(tmp_re, nbits); tabr[i].im = REF_SCALE(tmp_im, nbits); } } static void imdct_ref(FFTSample *out, FFTSample *in, int nbits) { int n = 1<<nbits; int k, i, a; double sum, f; for (i = 0; i < n; i++) { sum = 0; for (k = 0; k < n/2; k++) { a = (2 * i + 1 + (n / 2)) * (2 * k + 1); f = cos(M_PI * a / (double)(2 * n)); sum += f * in[k]; } out[i] = REF_SCALE(-sum, nbits - 2); } } /* NOTE: no normalisation by 1 / N is done */ static void mdct_ref(FFTSample *output, FFTSample *input, int nbits) { int n = 1<<nbits; int k, i; double a, s; /* do it by hand */ for (k = 0; k < n/2; k++) { s = 0; for (i = 0; i < n; i++) { a = (2*M_PI*(2*i+1+n/2)*(2*k+1) / (4 * n)); s += input[i] * cos(a); } output[k] = REF_SCALE(s, nbits - 1); } } #if CONFIG_FFT_FLOAT static void idct_ref(float *output, float *input, int nbits) { int n = 1<<nbits; int k, i; double a, s; /* do it by hand */ for (i = 0; i < n; i++) { s = 0.5 * input[0]; for (k = 1; k < n; k++) { a = M_PI*k*(i+0.5) / n; s += input[k] * cos(a); } output[i] = 2 * s / n; } } static void dct_ref(float *output, float *input, int nbits) { int n = 1<<nbits; int k, i; double a, s; /* do it by hand */ for (k = 0; k < n; k++) { s = 0; for (i = 0; i < n; i++) { a = M_PI*k*(i+0.5) / n; s += input[i] * cos(a); } output[k] = s; } } #endif static FFTSample frandom(AVLFG *prng) { return (int16_t)av_lfg_get(prng) / 32768.0 * RANGE; } static int64_t gettime(void) { struct timeval tv; gettimeofday(&tv,NULL); return (int64_t)tv.tv_sec * 1000000 + tv.tv_usec; } static int check_diff(FFTSample *tab1, FFTSample *tab2, int n, double scale) { int i; double max= 0; double error= 0; int err = 0; for (i = 0; i < n; i++) { double e = fabsf(tab1[i] - (tab2[i] / scale)) / RANGE; if (e >= 1e-3) { av_log(NULL, AV_LOG_ERROR, "ERROR %5d: "FMT" "FMT"\n", i, tab1[i], tab2[i]); err = 1; } error+= e*e; if(e>max) max= e; } av_log(NULL, AV_LOG_INFO, "max:%f e:%g\n", max, sqrt(error)/n); return err; } static void help(void) { av_log(NULL, AV_LOG_INFO,"usage: fft-test [-h] [-s] [-i] [-n b]\n" "-h print this help\n" "-s speed test\n" "-m (I)MDCT test\n" "-d (I)DCT test\n" "-r (I)RDFT test\n" "-i inverse transform test\n" "-n b set the transform size to 2^b\n" "-f x set scale factor for output data of (I)MDCT to x\n" ); } enum tf_transform { TRANSFORM_FFT, TRANSFORM_MDCT, TRANSFORM_RDFT, TRANSFORM_DCT, }; int main(int argc, char **argv) { FFTComplex *tab, *tab1, *tab_ref; FFTSample *tab2; int it, i, c; int do_speed = 0; int err = 1; enum tf_transform transform = TRANSFORM_FFT; int do_inverse = 0; FFTContext s1, *s = &s1; FFTContext m1, *m = &m1; #if CONFIG_FFT_FLOAT RDFTContext r1, *r = &r1; DCTContext d1, *d = &d1; int fft_size_2; #endif int fft_nbits, fft_size; double scale = 1.0; AVLFG prng; av_lfg_init(&prng, 1); fft_nbits = 9; for(;;) { c = getopt(argc, argv, "hsimrdn:f:"); if (c == -1) break; switch(c) { case 'h': help(); return 1; case 's': do_speed = 1; break; case 'i': do_inverse = 1; break; case 'm': transform = TRANSFORM_MDCT; break; case 'r': transform = TRANSFORM_RDFT; break; case 'd': transform = TRANSFORM_DCT; break; case 'n': fft_nbits = atoi(optarg); break; case 'f': scale = atof(optarg); break; } } fft_size = 1 << fft_nbits; tab = av_malloc(fft_size * sizeof(FFTComplex)); tab1 = av_malloc(fft_size * sizeof(FFTComplex)); tab_ref = av_malloc(fft_size * sizeof(FFTComplex)); tab2 = av_malloc(fft_size * sizeof(FFTSample)); switch (transform) { case TRANSFORM_MDCT: av_log(NULL, AV_LOG_INFO,"Scale factor is set to %f\n", scale); if (do_inverse) av_log(NULL, AV_LOG_INFO,"IMDCT"); else av_log(NULL, AV_LOG_INFO,"MDCT"); ff_mdct_init(m, fft_nbits, do_inverse, scale); break; case TRANSFORM_FFT: if (do_inverse) av_log(NULL, AV_LOG_INFO,"IFFT"); else av_log(NULL, AV_LOG_INFO,"FFT"); ff_fft_init(s, fft_nbits, do_inverse); fft_ref_init(fft_nbits, do_inverse); break; #if CONFIG_FFT_FLOAT case TRANSFORM_RDFT: if (do_inverse) av_log(NULL, AV_LOG_INFO,"IDFT_C2R"); else av_log(NULL, AV_LOG_INFO,"DFT_R2C"); ff_rdft_init(r, fft_nbits, do_inverse ? IDFT_C2R : DFT_R2C); fft_ref_init(fft_nbits, do_inverse); break; case TRANSFORM_DCT: if (do_inverse) av_log(NULL, AV_LOG_INFO,"DCT_III"); else av_log(NULL, AV_LOG_INFO,"DCT_II"); ff_dct_init(d, fft_nbits, do_inverse ? DCT_III : DCT_II); break; #endif default: av_log(NULL, AV_LOG_ERROR, "Requested transform not supported\n"); return 1; } av_log(NULL, AV_LOG_INFO," %d test\n", fft_size); /* generate random data */ for (i = 0; i < fft_size; i++) { tab1[i].re = frandom(&prng); tab1[i].im = frandom(&prng); } /* checking result */ av_log(NULL, AV_LOG_INFO,"Checking...\n"); switch (transform) { case TRANSFORM_MDCT: if (do_inverse) { imdct_ref((FFTSample *)tab_ref, (FFTSample *)tab1, fft_nbits); m->imdct_calc(m, tab2, (FFTSample *)tab1); err = check_diff((FFTSample *)tab_ref, tab2, fft_size, scale); } else { mdct_ref((FFTSample *)tab_ref, (FFTSample *)tab1, fft_nbits); m->mdct_calc(m, tab2, (FFTSample *)tab1); err = check_diff((FFTSample *)tab_ref, tab2, fft_size / 2, scale); } break; case TRANSFORM_FFT: memcpy(tab, tab1, fft_size * sizeof(FFTComplex)); s->fft_permute(s, tab); s->fft_calc(s, tab); fft_ref(tab_ref, tab1, fft_nbits); err = check_diff((FFTSample *)tab_ref, (FFTSample *)tab, fft_size * 2, 1.0); break; #if CONFIG_FFT_FLOAT case TRANSFORM_RDFT: fft_size_2 = fft_size >> 1; if (do_inverse) { tab1[ 0].im = 0; tab1[fft_size_2].im = 0; for (i = 1; i < fft_size_2; i++) { tab1[fft_size_2+i].re = tab1[fft_size_2-i].re; tab1[fft_size_2+i].im = -tab1[fft_size_2-i].im; } memcpy(tab2, tab1, fft_size * sizeof(FFTSample)); tab2[1] = tab1[fft_size_2].re; r->rdft_calc(r, tab2); fft_ref(tab_ref, tab1, fft_nbits); for (i = 0; i < fft_size; i++) { tab[i].re = tab2[i]; tab[i].im = 0; } err = check_diff((float *)tab_ref, (float *)tab, fft_size * 2, 0.5); } else { for (i = 0; i < fft_size; i++) { tab2[i] = tab1[i].re; tab1[i].im = 0; } r->rdft_calc(r, tab2); fft_ref(tab_ref, tab1, fft_nbits); tab_ref[0].im = tab_ref[fft_size_2].re; err = check_diff((float *)tab_ref, (float *)tab2, fft_size, 1.0); } break; case TRANSFORM_DCT: memcpy(tab, tab1, fft_size * sizeof(FFTComplex)); d->dct_calc(d, tab); if (do_inverse) { idct_ref(tab_ref, tab1, fft_nbits); } else { dct_ref(tab_ref, tab1, fft_nbits); } err = check_diff((float *)tab_ref, (float *)tab, fft_size, 1.0); break; #endif } /* do a speed test */ if (do_speed) { int64_t time_start, duration; int nb_its; av_log(NULL, AV_LOG_INFO,"Speed test...\n"); /* we measure during about 1 seconds */ nb_its = 1; for(;;) { time_start = gettime(); for (it = 0; it < nb_its; it++) { switch (transform) { case TRANSFORM_MDCT: if (do_inverse) { m->imdct_calc(m, (FFTSample *)tab, (FFTSample *)tab1); } else { m->mdct_calc(m, (FFTSample *)tab, (FFTSample *)tab1); } break; case TRANSFORM_FFT: memcpy(tab, tab1, fft_size * sizeof(FFTComplex)); s->fft_calc(s, tab); break; #if CONFIG_FFT_FLOAT case TRANSFORM_RDFT: memcpy(tab2, tab1, fft_size * sizeof(FFTSample)); r->rdft_calc(r, tab2); break; case TRANSFORM_DCT: memcpy(tab2, tab1, fft_size * sizeof(FFTSample)); d->dct_calc(d, tab2); break; #endif } } duration = gettime() - time_start; if (duration >= 1000000) break; nb_its *= 2; } av_log(NULL, AV_LOG_INFO,"time: %0.1f us/transform [total time=%0.2f s its=%d]\n", (double)duration / nb_its, (double)duration / 1000000.0, nb_its); } switch (transform) { case TRANSFORM_MDCT: ff_mdct_end(m); break; case TRANSFORM_FFT: ff_fft_end(s); break; #if CONFIG_FFT_FLOAT case TRANSFORM_RDFT: ff_rdft_end(r); break; case TRANSFORM_DCT: ff_dct_end(d); break; #endif } av_free(tab); av_free(tab1); av_free(tab2); av_free(tab_ref); av_free(exptab); return err; }