1/* 2 * (c) 2002 Fabrice Bellard 3 * 4 * This file is part of FFmpeg. 5 * 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. 10 * 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. 15 * 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 19 */ 20 21/** 22 * @file 23 * FFT and MDCT tests. 24 */ 25 26#include "libavutil/mathematics.h" 27#include "libavutil/lfg.h" 28#include "libavutil/log.h" 29#include "fft.h" 30#include <math.h> 31#include <unistd.h> 32#include <sys/time.h> 33#include <stdlib.h> 34#include <string.h> 35 36#undef exit 37 38/* reference fft */ 39 40#define MUL16(a,b) ((a) * (b)) 41 42#define CMAC(pre, pim, are, aim, bre, bim) \ 43{\ 44 pre += (MUL16(are, bre) - MUL16(aim, bim));\ 45 pim += (MUL16(are, bim) + MUL16(bre, aim));\ 46} 47 48FFTComplex *exptab; 49 50static void fft_ref_init(int nbits, int inverse) 51{ 52 int n, i; 53 double c1, s1, alpha; 54 55 n = 1 << nbits; 56 exptab = av_malloc((n / 2) * sizeof(FFTComplex)); 57 58 for (i = 0; i < (n/2); i++) { 59 alpha = 2 * M_PI * (float)i / (float)n; 60 c1 = cos(alpha); 61 s1 = sin(alpha); 62 if (!inverse) 63 s1 = -s1; 64 exptab[i].re = c1; 65 exptab[i].im = s1; 66 } 67} 68 69static void fft_ref(FFTComplex *tabr, FFTComplex *tab, int nbits) 70{ 71 int n, i, j, k, n2; 72 double tmp_re, tmp_im, s, c; 73 FFTComplex *q; 74 75 n = 1 << nbits; 76 n2 = n >> 1; 77 for (i = 0; i < n; i++) { 78 tmp_re = 0; 79 tmp_im = 0; 80 q = tab; 81 for (j = 0; j < n; j++) { 82 k = (i * j) & (n - 1); 83 if (k >= n2) { 84 c = -exptab[k - n2].re; 85 s = -exptab[k - n2].im; 86 } else { 87 c = exptab[k].re; 88 s = exptab[k].im; 89 } 90 CMAC(tmp_re, tmp_im, c, s, q->re, q->im); 91 q++; 92 } 93 tabr[i].re = tmp_re; 94 tabr[i].im = tmp_im; 95 } 96} 97 98static void imdct_ref(float *out, float *in, int nbits) 99{ 100 int n = 1<<nbits; 101 int k, i, a; 102 double sum, f; 103 104 for (i = 0; i < n; i++) { 105 sum = 0; 106 for (k = 0; k < n/2; k++) { 107 a = (2 * i + 1 + (n / 2)) * (2 * k + 1); 108 f = cos(M_PI * a / (double)(2 * n)); 109 sum += f * in[k]; 110 } 111 out[i] = -sum; 112 } 113} 114 115/* NOTE: no normalisation by 1 / N is done */ 116static void mdct_ref(float *output, float *input, int nbits) 117{ 118 int n = 1<<nbits; 119 int k, i; 120 double a, s; 121 122 /* do it by hand */ 123 for (k = 0; k < n/2; k++) { 124 s = 0; 125 for (i = 0; i < n; i++) { 126 a = (2*M_PI*(2*i+1+n/2)*(2*k+1) / (4 * n)); 127 s += input[i] * cos(a); 128 } 129 output[k] = s; 130 } 131} 132 133static void idct_ref(float *output, float *input, int nbits) 134{ 135 int n = 1<<nbits; 136 int k, i; 137 double a, s; 138 139 /* do it by hand */ 140 for (i = 0; i < n; i++) { 141 s = 0.5 * input[0]; 142 for (k = 1; k < n; k++) { 143 a = M_PI*k*(i+0.5) / n; 144 s += input[k] * cos(a); 145 } 146 output[i] = 2 * s / n; 147 } 148} 149static void dct_ref(float *output, float *input, int nbits) 150{ 151 int n = 1<<nbits; 152 int k, i; 153 double a, s; 154 155 /* do it by hand */ 156 for (k = 0; k < n; k++) { 157 s = 0; 158 for (i = 0; i < n; i++) { 159 a = M_PI*k*(i+0.5) / n; 160 s += input[i] * cos(a); 161 } 162 output[k] = s; 163 } 164} 165 166 167static float frandom(AVLFG *prng) 168{ 169 return (int16_t)av_lfg_get(prng) / 32768.0; 170} 171 172static int64_t gettime(void) 173{ 174 struct timeval tv; 175 gettimeofday(&tv,NULL); 176 return (int64_t)tv.tv_sec * 1000000 + tv.tv_usec; 177} 178 179static void check_diff(float *tab1, float *tab2, int n, double scale) 180{ 181 int i; 182 double max= 0; 183 double error= 0; 184 185 for (i = 0; i < n; i++) { 186 double e= fabsf(tab1[i] - (tab2[i] / scale)); 187 if (e >= 1e-3) { 188 av_log(NULL, AV_LOG_ERROR, "ERROR %d: %f %f\n", 189 i, tab1[i], tab2[i]); 190 } 191 error+= e*e; 192 if(e>max) max= e; 193 } 194 av_log(NULL, AV_LOG_INFO, "max:%f e:%g\n", max, sqrt(error)/n); 195} 196 197 198static void help(void) 199{ 200 av_log(NULL, AV_LOG_INFO,"usage: fft-test [-h] [-s] [-i] [-n b]\n" 201 "-h print this help\n" 202 "-s speed test\n" 203 "-m (I)MDCT test\n" 204 "-d (I)DCT test\n" 205 "-r (I)RDFT test\n" 206 "-i inverse transform test\n" 207 "-n b set the transform size to 2^b\n" 208 "-f x set scale factor for output data of (I)MDCT to x\n" 209 ); 210 exit(1); 211} 212 213enum tf_transform { 214 TRANSFORM_FFT, 215 TRANSFORM_MDCT, 216 TRANSFORM_RDFT, 217 TRANSFORM_DCT, 218}; 219 220int main(int argc, char **argv) 221{ 222 FFTComplex *tab, *tab1, *tab_ref; 223 FFTSample *tab2; 224 int it, i, c; 225 int do_speed = 0; 226 enum tf_transform transform = TRANSFORM_FFT; 227 int do_inverse = 0; 228 FFTContext s1, *s = &s1; 229 FFTContext m1, *m = &m1; 230 RDFTContext r1, *r = &r1; 231 DCTContext d1, *d = &d1; 232 int fft_nbits, fft_size, fft_size_2; 233 double scale = 1.0; 234 AVLFG prng; 235 av_lfg_init(&prng, 1); 236 237 fft_nbits = 9; 238 for(;;) { 239 c = getopt(argc, argv, "hsimrdn:f:"); 240 if (c == -1) 241 break; 242 switch(c) { 243 case 'h': 244 help(); 245 break; 246 case 's': 247 do_speed = 1; 248 break; 249 case 'i': 250 do_inverse = 1; 251 break; 252 case 'm': 253 transform = TRANSFORM_MDCT; 254 break; 255 case 'r': 256 transform = TRANSFORM_RDFT; 257 break; 258 case 'd': 259 transform = TRANSFORM_DCT; 260 break; 261 case 'n': 262 fft_nbits = atoi(optarg); 263 break; 264 case 'f': 265 scale = atof(optarg); 266 break; 267 } 268 } 269 270 fft_size = 1 << fft_nbits; 271 fft_size_2 = fft_size >> 1; 272 tab = av_malloc(fft_size * sizeof(FFTComplex)); 273 tab1 = av_malloc(fft_size * sizeof(FFTComplex)); 274 tab_ref = av_malloc(fft_size * sizeof(FFTComplex)); 275 tab2 = av_malloc(fft_size * sizeof(FFTSample)); 276 277 switch (transform) { 278 case TRANSFORM_MDCT: 279 av_log(NULL, AV_LOG_INFO,"Scale factor is set to %f\n", scale); 280 if (do_inverse) 281 av_log(NULL, AV_LOG_INFO,"IMDCT"); 282 else 283 av_log(NULL, AV_LOG_INFO,"MDCT"); 284 ff_mdct_init(m, fft_nbits, do_inverse, scale); 285 break; 286 case TRANSFORM_FFT: 287 if (do_inverse) 288 av_log(NULL, AV_LOG_INFO,"IFFT"); 289 else 290 av_log(NULL, AV_LOG_INFO,"FFT"); 291 ff_fft_init(s, fft_nbits, do_inverse); 292 fft_ref_init(fft_nbits, do_inverse); 293 break; 294 case TRANSFORM_RDFT: 295 if (do_inverse) 296 av_log(NULL, AV_LOG_INFO,"IDFT_C2R"); 297 else 298 av_log(NULL, AV_LOG_INFO,"DFT_R2C"); 299 ff_rdft_init(r, fft_nbits, do_inverse ? IDFT_C2R : DFT_R2C); 300 fft_ref_init(fft_nbits, do_inverse); 301 break; 302 case TRANSFORM_DCT: 303 if (do_inverse) 304 av_log(NULL, AV_LOG_INFO,"DCT_III"); 305 else 306 av_log(NULL, AV_LOG_INFO,"DCT_II"); 307 ff_dct_init(d, fft_nbits, do_inverse ? DCT_III : DCT_II); 308 break; 309 } 310 av_log(NULL, AV_LOG_INFO," %d test\n", fft_size); 311 312 /* generate random data */ 313 314 for (i = 0; i < fft_size; i++) { 315 tab1[i].re = frandom(&prng); 316 tab1[i].im = frandom(&prng); 317 } 318 319 /* checking result */ 320 av_log(NULL, AV_LOG_INFO,"Checking...\n"); 321 322 switch (transform) { 323 case TRANSFORM_MDCT: 324 if (do_inverse) { 325 imdct_ref((float *)tab_ref, (float *)tab1, fft_nbits); 326 ff_imdct_calc(m, tab2, (float *)tab1); 327 check_diff((float *)tab_ref, tab2, fft_size, scale); 328 } else { 329 mdct_ref((float *)tab_ref, (float *)tab1, fft_nbits); 330 331 ff_mdct_calc(m, tab2, (float *)tab1); 332 333 check_diff((float *)tab_ref, tab2, fft_size / 2, scale); 334 } 335 break; 336 case TRANSFORM_FFT: 337 memcpy(tab, tab1, fft_size * sizeof(FFTComplex)); 338 ff_fft_permute(s, tab); 339 ff_fft_calc(s, tab); 340 341 fft_ref(tab_ref, tab1, fft_nbits); 342 check_diff((float *)tab_ref, (float *)tab, fft_size * 2, 1.0); 343 break; 344 case TRANSFORM_RDFT: 345 if (do_inverse) { 346 tab1[ 0].im = 0; 347 tab1[fft_size_2].im = 0; 348 for (i = 1; i < fft_size_2; i++) { 349 tab1[fft_size_2+i].re = tab1[fft_size_2-i].re; 350 tab1[fft_size_2+i].im = -tab1[fft_size_2-i].im; 351 } 352 353 memcpy(tab2, tab1, fft_size * sizeof(FFTSample)); 354 tab2[1] = tab1[fft_size_2].re; 355 356 ff_rdft_calc(r, tab2); 357 fft_ref(tab_ref, tab1, fft_nbits); 358 for (i = 0; i < fft_size; i++) { 359 tab[i].re = tab2[i]; 360 tab[i].im = 0; 361 } 362 check_diff((float *)tab_ref, (float *)tab, fft_size * 2, 0.5); 363 } else { 364 for (i = 0; i < fft_size; i++) { 365 tab2[i] = tab1[i].re; 366 tab1[i].im = 0; 367 } 368 ff_rdft_calc(r, tab2); 369 fft_ref(tab_ref, tab1, fft_nbits); 370 tab_ref[0].im = tab_ref[fft_size_2].re; 371 check_diff((float *)tab_ref, (float *)tab2, fft_size, 1.0); 372 } 373 break; 374 case TRANSFORM_DCT: 375 memcpy(tab, tab1, fft_size * sizeof(FFTComplex)); 376 ff_dct_calc(d, tab); 377 if (do_inverse) { 378 idct_ref(tab_ref, tab1, fft_nbits); 379 } else { 380 dct_ref(tab_ref, tab1, fft_nbits); 381 } 382 check_diff((float *)tab_ref, (float *)tab, fft_size, 1.0); 383 break; 384 } 385 386 /* do a speed test */ 387 388 if (do_speed) { 389 int64_t time_start, duration; 390 int nb_its; 391 392 av_log(NULL, AV_LOG_INFO,"Speed test...\n"); 393 /* we measure during about 1 seconds */ 394 nb_its = 1; 395 for(;;) { 396 time_start = gettime(); 397 for (it = 0; it < nb_its; it++) { 398 switch (transform) { 399 case TRANSFORM_MDCT: 400 if (do_inverse) { 401 ff_imdct_calc(m, (float *)tab, (float *)tab1); 402 } else { 403 ff_mdct_calc(m, (float *)tab, (float *)tab1); 404 } 405 break; 406 case TRANSFORM_FFT: 407 memcpy(tab, tab1, fft_size * sizeof(FFTComplex)); 408 ff_fft_calc(s, tab); 409 break; 410 case TRANSFORM_RDFT: 411 memcpy(tab2, tab1, fft_size * sizeof(FFTSample)); 412 ff_rdft_calc(r, tab2); 413 break; 414 case TRANSFORM_DCT: 415 memcpy(tab2, tab1, fft_size * sizeof(FFTSample)); 416 ff_dct_calc(d, tab2); 417 break; 418 } 419 } 420 duration = gettime() - time_start; 421 if (duration >= 1000000) 422 break; 423 nb_its *= 2; 424 } 425 av_log(NULL, AV_LOG_INFO,"time: %0.1f us/transform [total time=%0.2f s its=%d]\n", 426 (double)duration / nb_its, 427 (double)duration / 1000000.0, 428 nb_its); 429 } 430 431 switch (transform) { 432 case TRANSFORM_MDCT: 433 ff_mdct_end(m); 434 break; 435 case TRANSFORM_FFT: 436 ff_fft_end(s); 437 break; 438 case TRANSFORM_RDFT: 439 ff_rdft_end(r); 440 break; 441 case TRANSFORM_DCT: 442 ff_dct_end(d); 443 break; 444 } 445 return 0; 446} 447