15
#define MUL16(a,b) ((a) * (b))
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#define CMAC(pre, pim, are, aim, bre, bim) \
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pre += (MUL16(are, bre) - MUL16(aim, bim));\
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pim += (MUL16(are, bim) + MUL16(bre, aim));\
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void fft_ref_init(int nbits, int inverse)
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exptab = av_malloc((n / 2) * sizeof(FFTComplex));
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for(i=0;i<(n/2);i++) {
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alpha = 2 * M_PI * (float)i / (float)n;
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void fft_ref(FFTComplex *tabr, FFTComplex *tab, int nbits)
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float tmp_re, tmp_im, s, c;
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k = (i * j) & (n - 1);
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c = -exptab[k - n2].re;
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s = -exptab[k - n2].im;
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CMAC(tmp_re, tmp_im, c, s, q->re, q->im);
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void imdct_ref(float *out, float *in, int n)
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a = (2 * i + 1 + (n / 2)) * (2 * k + 1);
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f = cos(M_PI * a / (double)(2 * n));
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/* NOTE: no normalisation by 1 / N is done */
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void mdct_ref(float *output, float *input, int n)
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a = (2*M_PI*(2*i+1+n/2)*(2*k+1) / (4 * n));
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s += input[i] * cos(a);
109
return (float)((random() & 0xffff) - 32768) / 32768.0;
112
int64_t gettime(void)
115
gettimeofday(&tv,NULL);
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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
av_log(NULL, AV_LOG_ERROR, "ERROR %d: %f %f\n",
126
i, tab1[i], tab2[i]);
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av_log(NULL, AV_LOG_INFO,"usage: fft-test [-h] [-s] [-i] [-n b]\n"
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"-h print this help\n"
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"-i inverse transform test\n"
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"-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;
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FFTContext s1, *s = &s1;
155
MDCTContext m1, *m = &m1;
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int fft_nbits, fft_size;
161
c = getopt(argc, argv, "hsimn:");
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fft_nbits = atoi(optarg);
183
fft_size = 1 << fft_nbits;
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tab = av_malloc(fft_size * sizeof(FFTComplex));
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tab1 = av_malloc(fft_size * sizeof(FFTComplex));
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tab_ref = av_malloc(fft_size * sizeof(FFTComplex));
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tabtmp = av_malloc(fft_size / 2 * sizeof(FFTSample));
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tab2 = av_malloc(fft_size * sizeof(FFTSample));
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av_log(NULL, AV_LOG_INFO,"IMDCT");
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av_log(NULL, AV_LOG_INFO,"MDCT");
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ff_mdct_init(m, fft_nbits, do_inverse);
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av_log(NULL, AV_LOG_INFO,"IFFT");
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av_log(NULL, AV_LOG_INFO,"FFT");
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ff_fft_init(s, fft_nbits, do_inverse);
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fft_ref_init(fft_nbits, do_inverse);
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av_log(NULL, AV_LOG_INFO," %d test\n", fft_size);
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/* generate random data */
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for(i=0;i<fft_size;i++) {
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tab1[i].re = frandom();
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tab1[i].im = frandom();
213
/* checking result */
214
av_log(NULL, AV_LOG_INFO,"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);
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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));
230
ff_fft_permute(s, tab);
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
av_log(NULL, AV_LOG_INFO,"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
av_log(NULL, AV_LOG_INFO,"time: %0.1f us/transform [total time=%0.2f s its=%d]\n",
266
(double)duration / nb_its,
267
(double)duration / 1000000.0,