15 #define MUL16(a,b) ((a) * (b))
17 #define CMAC(pre, pim, are, aim, bre, bim) \
19 pre += (MUL16(are, bre) - MUL16(aim, bim));\
20 pim += (MUL16(are, bim) + MUL16(bre, aim));\
25 void fft_ref_init(int nbits, int inverse)
31 exptab = av_malloc((n / 2) * sizeof(FFTComplex));
33 for(i=0;i<(n/2);i++) {
34 alpha = 2 * M_PI * (float)i / (float)n;
44 void fft_ref(FFTComplex *tabr, FFTComplex *tab, int nbits)
47 float tmp_re, tmp_im, s, c;
57 k = (i * j) & (n - 1);
59 c = -exptab[k - n2].re;
60 s = -exptab[k - n2].im;
65 CMAC(tmp_re, tmp_im, c, s, q->re, q->im);
73 void imdct_ref(float *out, float *in, int n)
81 a = (2 * i + 1 + (n / 2)) * (2 * k + 1);
82 f = cos(M_PI * a / (double)(2 * n));
89 /* NOTE: no normalisation by 1 / N is done */
90 void mdct_ref(float *output, float *input, int n)
99 a = (2*M_PI*(2*i+1+n/2)*(2*k+1) / (4 * n));
100 s += input[i] * cos(a);
109 return (float)((random() & 0xffff) - 32768) / 32768.0;
112 int64_t gettime(void)
115 gettimeofday(&tv,NULL);
116 return (int64_t)tv.tv_sec * 1000000 + tv.tv_usec;
119 void check_diff(float *tab1, float *tab2, int n)
124 if (fabsf(tab1[i] - tab2[i]) >= 1e-3) {
125 printf("ERROR %d: %f %f\n",
126 i, tab1[i], tab2[i]);
134 printf("usage: fft-test [-h] [-s] [-i] [-n b]\n"
135 "-h print this help\n"
138 "-i inverse transform test\n"
139 "-n b set the transform size to 2^b\n"
146 int main(int argc, char **argv)
148 FFTComplex *tab, *tab1, *tab_ref;
149 FFTSample *tabtmp, *tab2;
154 FFTContext s1, *s = &s1;
155 MDCTContext m1, *m = &m1;
156 int fft_nbits, fft_size;
161 c = getopt(argc, argv, "hsimn:");
178 fft_nbits = atoi(optarg);
183 fft_size = 1 << fft_nbits;
184 tab = av_malloc(fft_size * sizeof(FFTComplex));
185 tab1 = av_malloc(fft_size * sizeof(FFTComplex));
186 tab_ref = av_malloc(fft_size * sizeof(FFTComplex));
187 tabtmp = av_malloc(fft_size / 2 * sizeof(FFTSample));
188 tab2 = av_malloc(fft_size * sizeof(FFTSample));
195 ff_mdct_init(m, fft_nbits, do_inverse);
201 fft_init(s, fft_nbits, do_inverse);
202 fft_ref_init(fft_nbits, do_inverse);
204 printf(" %d test\n", fft_size);
206 /* generate random data */
208 for(i=0;i<fft_size;i++) {
209 tab1[i].re = frandom();
210 tab1[i].im = frandom();
213 /* checking result */
214 printf("Checking...\n");
218 imdct_ref((float *)tab_ref, (float *)tab1, fft_size);
219 ff_imdct_calc(m, tab2, (float *)tab1, tabtmp);
220 check_diff((float *)tab_ref, tab2, fft_size);
222 mdct_ref((float *)tab_ref, (float *)tab1, fft_size);
224 ff_mdct_calc(m, tab2, (float *)tab1, tabtmp);
226 check_diff((float *)tab_ref, tab2, fft_size / 2);
229 memcpy(tab, tab1, fft_size * sizeof(FFTComplex));
233 fft_ref(tab_ref, tab1, fft_nbits);
234 check_diff((float *)tab_ref, (float *)tab, fft_size * 2);
237 /* do a speed test */
240 int64_t time_start, duration;
243 printf("Speed test...\n");
244 /* we measure during about 1 seconds */
247 time_start = gettime();
248 for(it=0;it<nb_its;it++) {
251 ff_imdct_calc(m, (float *)tab, (float *)tab1, tabtmp);
253 ff_mdct_calc(m, (float *)tab, (float *)tab1, tabtmp);
256 memcpy(tab, tab1, fft_size * sizeof(FFTComplex));
260 duration = gettime() - time_start;
261 if (duration >= 1000000)
265 printf("time: %0.1f us/transform [total time=%0.2f s its=%d]\n",
266 (double)duration / nb_its,
267 (double)duration / 1000000.0,