2 * (c) 2002 Fabrice Bellard
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 * @file libavcodec/fft-test.c
26 #include "libavutil/lfg.h"
38 #define MUL16(a,b) ((a) * (b))
40 #define CMAC(pre, pim, are, aim, bre, bim) \
42 pre += (MUL16(are, bre) - MUL16(aim, bim));\
43 pim += (MUL16(are, bim) + MUL16(bre, aim));\
48 static void fft_ref_init(int nbits, int inverse)
54 exptab = av_malloc((n / 2) * sizeof(FFTComplex));
56 for(i=0;i<(n/2);i++) {
57 alpha = 2 * M_PI * (float)i / (float)n;
67 static void fft_ref(FFTComplex *tabr, FFTComplex *tab, int nbits)
70 double tmp_re, tmp_im, s, c;
80 k = (i * j) & (n - 1);
82 c = -exptab[k - n2].re;
83 s = -exptab[k - n2].im;
88 CMAC(tmp_re, tmp_im, c, s, q->re, q->im);
96 static void imdct_ref(float *out, float *in, int nbits)
105 a = (2 * i + 1 + (n / 2)) * (2 * k + 1);
106 f = cos(M_PI * a / (double)(2 * n));
113 /* NOTE: no normalisation by 1 / N is done */
114 static void mdct_ref(float *output, float *input, int nbits)
124 a = (2*M_PI*(2*i+1+n/2)*(2*k+1) / (4 * n));
125 s += input[i] * cos(a);
132 static float frandom(void)
135 av_lfg_init(&prng, 1);
136 return (float)((av_lfg_get(&prng) & 0xffff) - 32768) / 32768.0;
139 static int64_t gettime(void)
142 gettimeofday(&tv,NULL);
143 return (int64_t)tv.tv_sec * 1000000 + tv.tv_usec;
146 static void check_diff(float *tab1, float *tab2, int n, double scale)
153 double e= fabsf(tab1[i] - (tab2[i] / scale));
155 av_log(NULL, AV_LOG_ERROR, "ERROR %d: %f %f\n",
156 i, tab1[i], tab2[i]);
161 av_log(NULL, AV_LOG_INFO, "max:%f e:%g\n", max, sqrt(error)/n);
165 static void help(void)
167 av_log(NULL, AV_LOG_INFO,"usage: fft-test [-h] [-s] [-i] [-n b]\n"
168 "-h print this help\n"
171 "-i inverse transform test\n"
172 "-n b set the transform size to 2^b\n"
173 "-f x set scale factor for output data of (I)MDCT to x\n"
180 int main(int argc, char **argv)
182 FFTComplex *tab, *tab1, *tab_ref;
188 FFTContext s1, *s = &s1;
189 MDCTContext m1, *m = &m1;
190 int fft_nbits, fft_size;
195 c = getopt(argc, argv, "hsimn:f:");
212 fft_nbits = atoi(optarg);
215 scale = atof(optarg);
220 fft_size = 1 << fft_nbits;
221 tab = av_malloc(fft_size * sizeof(FFTComplex));
222 tab1 = av_malloc(fft_size * sizeof(FFTComplex));
223 tab_ref = av_malloc(fft_size * sizeof(FFTComplex));
224 tab2 = av_malloc(fft_size * sizeof(FFTSample));
227 av_log(NULL, AV_LOG_INFO,"Scale factor is set to %f\n", scale);
229 av_log(NULL, AV_LOG_INFO,"IMDCT");
231 av_log(NULL, AV_LOG_INFO,"MDCT");
232 ff_mdct_init(m, fft_nbits, do_inverse, scale);
235 av_log(NULL, AV_LOG_INFO,"IFFT");
237 av_log(NULL, AV_LOG_INFO,"FFT");
238 ff_fft_init(s, fft_nbits, do_inverse);
239 fft_ref_init(fft_nbits, do_inverse);
241 av_log(NULL, AV_LOG_INFO," %d test\n", fft_size);
243 /* generate random data */
245 for(i=0;i<fft_size;i++) {
246 tab1[i].re = frandom();
247 tab1[i].im = frandom();
250 /* checking result */
251 av_log(NULL, AV_LOG_INFO,"Checking...\n");
255 imdct_ref((float *)tab_ref, (float *)tab1, fft_nbits);
256 ff_imdct_calc(m, tab2, (float *)tab1);
257 check_diff((float *)tab_ref, tab2, fft_size, scale);
259 mdct_ref((float *)tab_ref, (float *)tab1, fft_nbits);
261 ff_mdct_calc(m, tab2, (float *)tab1);
263 check_diff((float *)tab_ref, tab2, fft_size / 2, scale);
266 memcpy(tab, tab1, fft_size * sizeof(FFTComplex));
267 ff_fft_permute(s, tab);
270 fft_ref(tab_ref, tab1, fft_nbits);
271 check_diff((float *)tab_ref, (float *)tab, fft_size * 2, 1.0);
274 /* do a speed test */
277 int64_t time_start, duration;
280 av_log(NULL, AV_LOG_INFO,"Speed test...\n");
281 /* we measure during about 1 seconds */
284 time_start = gettime();
285 for(it=0;it<nb_its;it++) {
288 ff_imdct_calc(m, (float *)tab, (float *)tab1);
290 ff_mdct_calc(m, (float *)tab, (float *)tab1);
293 memcpy(tab, tab1, fft_size * sizeof(FFTComplex));
297 duration = gettime() - time_start;
298 if (duration >= 1000000)
302 av_log(NULL, AV_LOG_INFO,"time: %0.1f us/transform [total time=%0.2f s its=%d]\n",
303 (double)duration / nb_its,
304 (double)duration / 1000000.0,