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00026 #include "libavutil/mathematics.h"
00027 #include "libavutil/lfg.h"
00028 #include "libavutil/log.h"
00029 #include "fft.h"
00030 #include <math.h>
00031 #include <unistd.h>
00032 #include <sys/time.h>
00033 #include <stdlib.h>
00034 #include <string.h>
00035
00036 #undef exit
00037
00038
00039
00040 #define MUL16(a,b) ((a) * (b))
00041
00042 #define CMAC(pre, pim, are, aim, bre, bim) \
00043 {\
00044 pre += (MUL16(are, bre) - MUL16(aim, bim));\
00045 pim += (MUL16(are, bim) + MUL16(bre, aim));\
00046 }
00047
00048 FFTComplex *exptab;
00049
00050 static void fft_ref_init(int nbits, int inverse)
00051 {
00052 int n, i;
00053 double c1, s1, alpha;
00054
00055 n = 1 << nbits;
00056 exptab = av_malloc((n / 2) * sizeof(FFTComplex));
00057
00058 for (i = 0; i < (n/2); i++) {
00059 alpha = 2 * M_PI * (float)i / (float)n;
00060 c1 = cos(alpha);
00061 s1 = sin(alpha);
00062 if (!inverse)
00063 s1 = -s1;
00064 exptab[i].re = c1;
00065 exptab[i].im = s1;
00066 }
00067 }
00068
00069 static void fft_ref(FFTComplex *tabr, FFTComplex *tab, int nbits)
00070 {
00071 int n, i, j, k, n2;
00072 double tmp_re, tmp_im, s, c;
00073 FFTComplex *q;
00074
00075 n = 1 << nbits;
00076 n2 = n >> 1;
00077 for (i = 0; i < n; i++) {
00078 tmp_re = 0;
00079 tmp_im = 0;
00080 q = tab;
00081 for (j = 0; j < n; j++) {
00082 k = (i * j) & (n - 1);
00083 if (k >= n2) {
00084 c = -exptab[k - n2].re;
00085 s = -exptab[k - n2].im;
00086 } else {
00087 c = exptab[k].re;
00088 s = exptab[k].im;
00089 }
00090 CMAC(tmp_re, tmp_im, c, s, q->re, q->im);
00091 q++;
00092 }
00093 tabr[i].re = tmp_re;
00094 tabr[i].im = tmp_im;
00095 }
00096 }
00097
00098 static void imdct_ref(float *out, float *in, int nbits)
00099 {
00100 int n = 1<<nbits;
00101 int k, i, a;
00102 double sum, f;
00103
00104 for (i = 0; i < n; i++) {
00105 sum = 0;
00106 for (k = 0; k < n/2; k++) {
00107 a = (2 * i + 1 + (n / 2)) * (2 * k + 1);
00108 f = cos(M_PI * a / (double)(2 * n));
00109 sum += f * in[k];
00110 }
00111 out[i] = -sum;
00112 }
00113 }
00114
00115
00116 static void mdct_ref(float *output, float *input, int nbits)
00117 {
00118 int n = 1<<nbits;
00119 int k, i;
00120 double a, s;
00121
00122
00123 for (k = 0; k < n/2; k++) {
00124 s = 0;
00125 for (i = 0; i < n; i++) {
00126 a = (2*M_PI*(2*i+1+n/2)*(2*k+1) / (4 * n));
00127 s += input[i] * cos(a);
00128 }
00129 output[k] = s;
00130 }
00131 }
00132
00133 static void idct_ref(float *output, float *input, int nbits)
00134 {
00135 int n = 1<<nbits;
00136 int k, i;
00137 double a, s;
00138
00139
00140 for (i = 0; i < n; i++) {
00141 s = 0.5 * input[0];
00142 for (k = 1; k < n; k++) {
00143 a = M_PI*k*(i+0.5) / n;
00144 s += input[k] * cos(a);
00145 }
00146 output[i] = 2 * s / n;
00147 }
00148 }
00149 static void dct_ref(float *output, float *input, int nbits)
00150 {
00151 int n = 1<<nbits;
00152 int k, i;
00153 double a, s;
00154
00155
00156 for (k = 0; k < n; k++) {
00157 s = 0;
00158 for (i = 0; i < n; i++) {
00159 a = M_PI*k*(i+0.5) / n;
00160 s += input[i] * cos(a);
00161 }
00162 output[k] = s;
00163 }
00164 }
00165
00166
00167 static float frandom(AVLFG *prng)
00168 {
00169 return (int16_t)av_lfg_get(prng) / 32768.0;
00170 }
00171
00172 static int64_t gettime(void)
00173 {
00174 struct timeval tv;
00175 gettimeofday(&tv,NULL);
00176 return (int64_t)tv.tv_sec * 1000000 + tv.tv_usec;
00177 }
00178
00179 static int check_diff(float *tab1, float *tab2, int n, double scale)
00180 {
00181 int i;
00182 double max= 0;
00183 double error= 0;
00184 int err = 0;
00185
00186 for (i = 0; i < n; i++) {
00187 double e= fabsf(tab1[i] - (tab2[i] / scale));
00188 if (e >= 1e-3) {
00189 av_log(NULL, AV_LOG_ERROR, "ERROR %5d: %10.6f %10.6f\n",
00190 i, tab1[i], tab2[i]);
00191 err = 1;
00192 }
00193 error+= e*e;
00194 if(e>max) max= e;
00195 }
00196 av_log(NULL, AV_LOG_INFO, "max:%f e:%g\n", max, sqrt(error)/n);
00197 return err;
00198 }
00199
00200
00201 static void help(void)
00202 {
00203 av_log(NULL, AV_LOG_INFO,"usage: fft-test [-h] [-s] [-i] [-n b]\n"
00204 "-h print this help\n"
00205 "-s speed test\n"
00206 "-m (I)MDCT test\n"
00207 "-d (I)DCT test\n"
00208 "-r (I)RDFT test\n"
00209 "-i inverse transform test\n"
00210 "-n b set the transform size to 2^b\n"
00211 "-f x set scale factor for output data of (I)MDCT to x\n"
00212 );
00213 exit(1);
00214 }
00215
00216 enum tf_transform {
00217 TRANSFORM_FFT,
00218 TRANSFORM_MDCT,
00219 TRANSFORM_RDFT,
00220 TRANSFORM_DCT,
00221 };
00222
00223 int main(int argc, char **argv)
00224 {
00225 FFTComplex *tab, *tab1, *tab_ref;
00226 FFTSample *tab2;
00227 int it, i, c;
00228 int do_speed = 0;
00229 int err = 1;
00230 enum tf_transform transform = TRANSFORM_FFT;
00231 int do_inverse = 0;
00232 FFTContext s1, *s = &s1;
00233 FFTContext m1, *m = &m1;
00234 RDFTContext r1, *r = &r1;
00235 DCTContext d1, *d = &d1;
00236 int fft_nbits, fft_size, fft_size_2;
00237 double scale = 1.0;
00238 AVLFG prng;
00239 av_lfg_init(&prng, 1);
00240
00241 fft_nbits = 9;
00242 for(;;) {
00243 c = getopt(argc, argv, "hsimrdn:f:");
00244 if (c == -1)
00245 break;
00246 switch(c) {
00247 case 'h':
00248 help();
00249 break;
00250 case 's':
00251 do_speed = 1;
00252 break;
00253 case 'i':
00254 do_inverse = 1;
00255 break;
00256 case 'm':
00257 transform = TRANSFORM_MDCT;
00258 break;
00259 case 'r':
00260 transform = TRANSFORM_RDFT;
00261 break;
00262 case 'd':
00263 transform = TRANSFORM_DCT;
00264 break;
00265 case 'n':
00266 fft_nbits = atoi(optarg);
00267 break;
00268 case 'f':
00269 scale = atof(optarg);
00270 break;
00271 }
00272 }
00273
00274 fft_size = 1 << fft_nbits;
00275 fft_size_2 = fft_size >> 1;
00276 tab = av_malloc(fft_size * sizeof(FFTComplex));
00277 tab1 = av_malloc(fft_size * sizeof(FFTComplex));
00278 tab_ref = av_malloc(fft_size * sizeof(FFTComplex));
00279 tab2 = av_malloc(fft_size * sizeof(FFTSample));
00280
00281 switch (transform) {
00282 case TRANSFORM_MDCT:
00283 av_log(NULL, AV_LOG_INFO,"Scale factor is set to %f\n", scale);
00284 if (do_inverse)
00285 av_log(NULL, AV_LOG_INFO,"IMDCT");
00286 else
00287 av_log(NULL, AV_LOG_INFO,"MDCT");
00288 ff_mdct_init(m, fft_nbits, do_inverse, scale);
00289 break;
00290 case TRANSFORM_FFT:
00291 if (do_inverse)
00292 av_log(NULL, AV_LOG_INFO,"IFFT");
00293 else
00294 av_log(NULL, AV_LOG_INFO,"FFT");
00295 ff_fft_init(s, fft_nbits, do_inverse);
00296 fft_ref_init(fft_nbits, do_inverse);
00297 break;
00298 case TRANSFORM_RDFT:
00299 if (do_inverse)
00300 av_log(NULL, AV_LOG_INFO,"IDFT_C2R");
00301 else
00302 av_log(NULL, AV_LOG_INFO,"DFT_R2C");
00303 ff_rdft_init(r, fft_nbits, do_inverse ? IDFT_C2R : DFT_R2C);
00304 fft_ref_init(fft_nbits, do_inverse);
00305 break;
00306 case TRANSFORM_DCT:
00307 if (do_inverse)
00308 av_log(NULL, AV_LOG_INFO,"DCT_III");
00309 else
00310 av_log(NULL, AV_LOG_INFO,"DCT_II");
00311 ff_dct_init(d, fft_nbits, do_inverse ? DCT_III : DCT_II);
00312 break;
00313 }
00314 av_log(NULL, AV_LOG_INFO," %d test\n", fft_size);
00315
00316
00317
00318 for (i = 0; i < fft_size; i++) {
00319 tab1[i].re = frandom(&prng);
00320 tab1[i].im = frandom(&prng);
00321 }
00322
00323
00324 av_log(NULL, AV_LOG_INFO,"Checking...\n");
00325
00326 switch (transform) {
00327 case TRANSFORM_MDCT:
00328 if (do_inverse) {
00329 imdct_ref((float *)tab_ref, (float *)tab1, fft_nbits);
00330 ff_imdct_calc(m, tab2, (float *)tab1);
00331 err = check_diff((float *)tab_ref, tab2, fft_size, scale);
00332 } else {
00333 mdct_ref((float *)tab_ref, (float *)tab1, fft_nbits);
00334
00335 ff_mdct_calc(m, tab2, (float *)tab1);
00336
00337 err = check_diff((float *)tab_ref, tab2, fft_size / 2, scale);
00338 }
00339 break;
00340 case TRANSFORM_FFT:
00341 memcpy(tab, tab1, fft_size * sizeof(FFTComplex));
00342 ff_fft_permute(s, tab);
00343 ff_fft_calc(s, tab);
00344
00345 fft_ref(tab_ref, tab1, fft_nbits);
00346 err = check_diff((float *)tab_ref, (float *)tab, fft_size * 2, 1.0);
00347 break;
00348 case TRANSFORM_RDFT:
00349 if (do_inverse) {
00350 tab1[ 0].im = 0;
00351 tab1[fft_size_2].im = 0;
00352 for (i = 1; i < fft_size_2; i++) {
00353 tab1[fft_size_2+i].re = tab1[fft_size_2-i].re;
00354 tab1[fft_size_2+i].im = -tab1[fft_size_2-i].im;
00355 }
00356
00357 memcpy(tab2, tab1, fft_size * sizeof(FFTSample));
00358 tab2[1] = tab1[fft_size_2].re;
00359
00360 ff_rdft_calc(r, tab2);
00361 fft_ref(tab_ref, tab1, fft_nbits);
00362 for (i = 0; i < fft_size; i++) {
00363 tab[i].re = tab2[i];
00364 tab[i].im = 0;
00365 }
00366 err = check_diff((float *)tab_ref, (float *)tab, fft_size * 2, 0.5);
00367 } else {
00368 for (i = 0; i < fft_size; i++) {
00369 tab2[i] = tab1[i].re;
00370 tab1[i].im = 0;
00371 }
00372 ff_rdft_calc(r, tab2);
00373 fft_ref(tab_ref, tab1, fft_nbits);
00374 tab_ref[0].im = tab_ref[fft_size_2].re;
00375 err = check_diff((float *)tab_ref, (float *)tab2, fft_size, 1.0);
00376 }
00377 break;
00378 case TRANSFORM_DCT:
00379 memcpy(tab, tab1, fft_size * sizeof(FFTComplex));
00380 ff_dct_calc(d, tab);
00381 if (do_inverse) {
00382 idct_ref(tab_ref, tab1, fft_nbits);
00383 } else {
00384 dct_ref(tab_ref, tab1, fft_nbits);
00385 }
00386 err = check_diff((float *)tab_ref, (float *)tab, fft_size, 1.0);
00387 break;
00388 }
00389
00390
00391
00392 if (do_speed) {
00393 int64_t time_start, duration;
00394 int nb_its;
00395
00396 av_log(NULL, AV_LOG_INFO,"Speed test...\n");
00397
00398 nb_its = 1;
00399 for(;;) {
00400 time_start = gettime();
00401 for (it = 0; it < nb_its; it++) {
00402 switch (transform) {
00403 case TRANSFORM_MDCT:
00404 if (do_inverse) {
00405 ff_imdct_calc(m, (float *)tab, (float *)tab1);
00406 } else {
00407 ff_mdct_calc(m, (float *)tab, (float *)tab1);
00408 }
00409 break;
00410 case TRANSFORM_FFT:
00411 memcpy(tab, tab1, fft_size * sizeof(FFTComplex));
00412 ff_fft_calc(s, tab);
00413 break;
00414 case TRANSFORM_RDFT:
00415 memcpy(tab2, tab1, fft_size * sizeof(FFTSample));
00416 ff_rdft_calc(r, tab2);
00417 break;
00418 case TRANSFORM_DCT:
00419 memcpy(tab2, tab1, fft_size * sizeof(FFTSample));
00420 ff_dct_calc(d, tab2);
00421 break;
00422 }
00423 }
00424 duration = gettime() - time_start;
00425 if (duration >= 1000000)
00426 break;
00427 nb_its *= 2;
00428 }
00429 av_log(NULL, AV_LOG_INFO,"time: %0.1f us/transform [total time=%0.2f s its=%d]\n",
00430 (double)duration / nb_its,
00431 (double)duration / 1000000.0,
00432 nb_its);
00433 }
00434
00435 switch (transform) {
00436 case TRANSFORM_MDCT:
00437 ff_mdct_end(m);
00438 break;
00439 case TRANSFORM_FFT:
00440 ff_fft_end(s);
00441 break;
00442 case TRANSFORM_RDFT:
00443 ff_rdft_end(r);
00444 break;
00445 case TRANSFORM_DCT:
00446 ff_dct_end(d);
00447 break;
00448 }
00449
00450 av_free(tab);
00451 av_free(tab1);
00452 av_free(tab2);
00453 av_free(tab_ref);
00454 av_free(exptab);
00455
00456 return err;
00457 }