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1 | /* |
2 | * FFT/IFFT transforms | |
3 | * Copyright (c) 2008 Loren Merritt | |
4 | * Copyright (c) 2002 Fabrice Bellard | |
5 | * Partly based on libdjbfft by D. J. Bernstein | |
6 | * | |
7 | * This file is part of FFmpeg. | |
8 | * | |
9 | * FFmpeg is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU Lesser General Public | |
11 | * License as published by the Free Software Foundation; either | |
12 | * version 2.1 of the License, or (at your option) any later version. | |
13 | * | |
14 | * FFmpeg is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | * Lesser General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU Lesser General Public | |
20 | * License along with FFmpeg; if not, write to the Free Software | |
21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
22 | */ | |
23 | ||
24 | /** | |
25 | * @file | |
26 | * FFT/IFFT transforms. | |
27 | */ | |
28 | ||
29 | #include <stdlib.h> | |
30 | #include <string.h> | |
31 | #include "libavutil/mathematics.h" | |
32 | #include "fft.h" | |
33 | #include "fft-internal.h" | |
34 | ||
35 | #if FFT_FIXED_32 | |
36 | #include "fft_table.h" | |
37 | #else /* FFT_FIXED_32 */ | |
38 | ||
39 | /* cos(2*pi*x/n) for 0<=x<=n/4, followed by its reverse */ | |
40 | #if !CONFIG_HARDCODED_TABLES | |
41 | COSTABLE(16); | |
42 | COSTABLE(32); | |
43 | COSTABLE(64); | |
44 | COSTABLE(128); | |
45 | COSTABLE(256); | |
46 | COSTABLE(512); | |
47 | COSTABLE(1024); | |
48 | COSTABLE(2048); | |
49 | COSTABLE(4096); | |
50 | COSTABLE(8192); | |
51 | COSTABLE(16384); | |
52 | COSTABLE(32768); | |
53 | COSTABLE(65536); | |
54 | #endif | |
55 | COSTABLE_CONST FFTSample * const FFT_NAME(ff_cos_tabs)[] = { | |
56 | NULL, NULL, NULL, NULL, | |
57 | FFT_NAME(ff_cos_16), | |
58 | FFT_NAME(ff_cos_32), | |
59 | FFT_NAME(ff_cos_64), | |
60 | FFT_NAME(ff_cos_128), | |
61 | FFT_NAME(ff_cos_256), | |
62 | FFT_NAME(ff_cos_512), | |
63 | FFT_NAME(ff_cos_1024), | |
64 | FFT_NAME(ff_cos_2048), | |
65 | FFT_NAME(ff_cos_4096), | |
66 | FFT_NAME(ff_cos_8192), | |
67 | FFT_NAME(ff_cos_16384), | |
68 | FFT_NAME(ff_cos_32768), | |
69 | FFT_NAME(ff_cos_65536), | |
70 | }; | |
71 | ||
72 | #endif /* FFT_FIXED_32 */ | |
73 | ||
74 | static void fft_permute_c(FFTContext *s, FFTComplex *z); | |
75 | static void fft_calc_c(FFTContext *s, FFTComplex *z); | |
76 | ||
77 | static int split_radix_permutation(int i, int n, int inverse) | |
78 | { | |
79 | int m; | |
80 | if(n <= 2) return i&1; | |
81 | m = n >> 1; | |
82 | if(!(i&m)) return split_radix_permutation(i, m, inverse)*2; | |
83 | m >>= 1; | |
84 | if(inverse == !(i&m)) return split_radix_permutation(i, m, inverse)*4 + 1; | |
85 | else return split_radix_permutation(i, m, inverse)*4 - 1; | |
86 | } | |
87 | ||
88 | av_cold void ff_init_ff_cos_tabs(int index) | |
89 | { | |
90 | #if (!CONFIG_HARDCODED_TABLES) && (!FFT_FIXED_32) | |
91 | int i; | |
92 | int m = 1<<index; | |
93 | double freq = 2*M_PI/m; | |
94 | FFTSample *tab = FFT_NAME(ff_cos_tabs)[index]; | |
95 | for(i=0; i<=m/4; i++) | |
96 | tab[i] = FIX15(cos(i*freq)); | |
97 | for(i=1; i<m/4; i++) | |
98 | tab[m/2-i] = tab[i]; | |
99 | #endif | |
100 | } | |
101 | ||
102 | static const int avx_tab[] = { | |
103 | 0, 4, 1, 5, 8, 12, 9, 13, 2, 6, 3, 7, 10, 14, 11, 15 | |
104 | }; | |
105 | ||
106 | static int is_second_half_of_fft32(int i, int n) | |
107 | { | |
108 | if (n <= 32) | |
109 | return i >= 16; | |
110 | else if (i < n/2) | |
111 | return is_second_half_of_fft32(i, n/2); | |
112 | else if (i < 3*n/4) | |
113 | return is_second_half_of_fft32(i - n/2, n/4); | |
114 | else | |
115 | return is_second_half_of_fft32(i - 3*n/4, n/4); | |
116 | } | |
117 | ||
118 | static av_cold void fft_perm_avx(FFTContext *s) | |
119 | { | |
120 | int i; | |
121 | int n = 1 << s->nbits; | |
122 | ||
123 | for (i = 0; i < n; i += 16) { | |
124 | int k; | |
125 | if (is_second_half_of_fft32(i, n)) { | |
126 | for (k = 0; k < 16; k++) | |
127 | s->revtab[-split_radix_permutation(i + k, n, s->inverse) & (n - 1)] = | |
128 | i + avx_tab[k]; | |
129 | ||
130 | } else { | |
131 | for (k = 0; k < 16; k++) { | |
132 | int j = i + k; | |
133 | j = (j & ~7) | ((j >> 1) & 3) | ((j << 2) & 4); | |
134 | s->revtab[-split_radix_permutation(i + k, n, s->inverse) & (n - 1)] = j; | |
135 | } | |
136 | } | |
137 | } | |
138 | } | |
139 | ||
140 | av_cold int ff_fft_init(FFTContext *s, int nbits, int inverse) | |
141 | { | |
142 | int i, j, n; | |
143 | ||
144 | if (nbits < 2 || nbits > 16) | |
145 | goto fail; | |
146 | s->nbits = nbits; | |
147 | n = 1 << nbits; | |
148 | ||
149 | s->revtab = av_malloc(n * sizeof(uint16_t)); | |
150 | if (!s->revtab) | |
151 | goto fail; | |
152 | s->tmp_buf = av_malloc(n * sizeof(FFTComplex)); | |
153 | if (!s->tmp_buf) | |
154 | goto fail; | |
155 | s->inverse = inverse; | |
156 | s->fft_permutation = FF_FFT_PERM_DEFAULT; | |
157 | ||
158 | s->fft_permute = fft_permute_c; | |
159 | s->fft_calc = fft_calc_c; | |
160 | #if CONFIG_MDCT | |
161 | s->imdct_calc = ff_imdct_calc_c; | |
162 | s->imdct_half = ff_imdct_half_c; | |
163 | s->mdct_calc = ff_mdct_calc_c; | |
164 | #endif | |
165 | ||
166 | #if FFT_FIXED_32 | |
167 | { | |
168 | int n=0; | |
169 | ff_fft_lut_init(ff_fft_offsets_lut, 0, 1 << 16, &n); | |
170 | } | |
171 | #else /* FFT_FIXED_32 */ | |
172 | #if FFT_FLOAT | |
173 | if (ARCH_AARCH64) ff_fft_init_aarch64(s); | |
174 | if (ARCH_ARM) ff_fft_init_arm(s); | |
175 | if (ARCH_PPC) ff_fft_init_ppc(s); | |
176 | if (ARCH_X86) ff_fft_init_x86(s); | |
177 | if (CONFIG_MDCT) s->mdct_calcw = s->mdct_calc; | |
178 | if (HAVE_MIPSFPU) ff_fft_init_mips(s); | |
179 | #else | |
180 | if (CONFIG_MDCT) s->mdct_calcw = ff_mdct_calcw_c; | |
181 | if (ARCH_ARM) ff_fft_fixed_init_arm(s); | |
182 | #endif | |
183 | for(j=4; j<=nbits; j++) { | |
184 | ff_init_ff_cos_tabs(j); | |
185 | } | |
186 | #endif /* FFT_FIXED_32 */ | |
187 | ||
188 | ||
189 | if (s->fft_permutation == FF_FFT_PERM_AVX) { | |
190 | fft_perm_avx(s); | |
191 | } else { | |
192 | for(i=0; i<n; i++) { | |
193 | j = i; | |
194 | if (s->fft_permutation == FF_FFT_PERM_SWAP_LSBS) | |
195 | j = (j&~3) | ((j>>1)&1) | ((j<<1)&2); | |
196 | s->revtab[-split_radix_permutation(i, n, s->inverse) & (n-1)] = j; | |
197 | } | |
198 | } | |
199 | ||
200 | return 0; | |
201 | fail: | |
202 | av_freep(&s->revtab); | |
203 | av_freep(&s->tmp_buf); | |
204 | return -1; | |
205 | } | |
206 | ||
207 | static void fft_permute_c(FFTContext *s, FFTComplex *z) | |
208 | { | |
209 | int j, np; | |
210 | const uint16_t *revtab = s->revtab; | |
211 | np = 1 << s->nbits; | |
212 | /* TODO: handle split-radix permute in a more optimal way, probably in-place */ | |
213 | for(j=0;j<np;j++) s->tmp_buf[revtab[j]] = z[j]; | |
214 | memcpy(z, s->tmp_buf, np * sizeof(FFTComplex)); | |
215 | } | |
216 | ||
217 | av_cold void ff_fft_end(FFTContext *s) | |
218 | { | |
219 | av_freep(&s->revtab); | |
220 | av_freep(&s->tmp_buf); | |
221 | } | |
222 | ||
223 | #if FFT_FIXED_32 | |
224 | ||
225 | static void fft_calc_c(FFTContext *s, FFTComplex *z) { | |
226 | ||
227 | int nbits, i, n, num_transforms, offset, step; | |
228 | int n4, n2, n34; | |
229 | FFTSample tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, tmp8; | |
230 | FFTComplex *tmpz; | |
231 | const int fft_size = (1 << s->nbits); | |
232 | int64_t accu; | |
233 | ||
234 | num_transforms = (0x2aab >> (16 - s->nbits)) | 1; | |
235 | ||
236 | for (n=0; n<num_transforms; n++){ | |
237 | offset = ff_fft_offsets_lut[n] << 2; | |
238 | tmpz = z + offset; | |
239 | ||
240 | tmp1 = tmpz[0].re + tmpz[1].re; | |
241 | tmp5 = tmpz[2].re + tmpz[3].re; | |
242 | tmp2 = tmpz[0].im + tmpz[1].im; | |
243 | tmp6 = tmpz[2].im + tmpz[3].im; | |
244 | tmp3 = tmpz[0].re - tmpz[1].re; | |
245 | tmp8 = tmpz[2].im - tmpz[3].im; | |
246 | tmp4 = tmpz[0].im - tmpz[1].im; | |
247 | tmp7 = tmpz[2].re - tmpz[3].re; | |
248 | ||
249 | tmpz[0].re = tmp1 + tmp5; | |
250 | tmpz[2].re = tmp1 - tmp5; | |
251 | tmpz[0].im = tmp2 + tmp6; | |
252 | tmpz[2].im = tmp2 - tmp6; | |
253 | tmpz[1].re = tmp3 + tmp8; | |
254 | tmpz[3].re = tmp3 - tmp8; | |
255 | tmpz[1].im = tmp4 - tmp7; | |
256 | tmpz[3].im = tmp4 + tmp7; | |
257 | } | |
258 | ||
259 | if (fft_size < 8) | |
260 | return; | |
261 | ||
262 | num_transforms = (num_transforms >> 1) | 1; | |
263 | ||
264 | for (n=0; n<num_transforms; n++){ | |
265 | offset = ff_fft_offsets_lut[n] << 3; | |
266 | tmpz = z + offset; | |
267 | ||
268 | tmp1 = tmpz[4].re + tmpz[5].re; | |
269 | tmp3 = tmpz[6].re + tmpz[7].re; | |
270 | tmp2 = tmpz[4].im + tmpz[5].im; | |
271 | tmp4 = tmpz[6].im + tmpz[7].im; | |
272 | tmp5 = tmp1 + tmp3; | |
273 | tmp7 = tmp1 - tmp3; | |
274 | tmp6 = tmp2 + tmp4; | |
275 | tmp8 = tmp2 - tmp4; | |
276 | ||
277 | tmp1 = tmpz[4].re - tmpz[5].re; | |
278 | tmp2 = tmpz[4].im - tmpz[5].im; | |
279 | tmp3 = tmpz[6].re - tmpz[7].re; | |
280 | tmp4 = tmpz[6].im - tmpz[7].im; | |
281 | ||
282 | tmpz[4].re = tmpz[0].re - tmp5; | |
283 | tmpz[0].re = tmpz[0].re + tmp5; | |
284 | tmpz[4].im = tmpz[0].im - tmp6; | |
285 | tmpz[0].im = tmpz[0].im + tmp6; | |
286 | tmpz[6].re = tmpz[2].re - tmp8; | |
287 | tmpz[2].re = tmpz[2].re + tmp8; | |
288 | tmpz[6].im = tmpz[2].im + tmp7; | |
289 | tmpz[2].im = tmpz[2].im - tmp7; | |
290 | ||
291 | accu = (int64_t)Q31(M_SQRT1_2)*(tmp1 + tmp2); | |
292 | tmp5 = (int32_t)((accu + 0x40000000) >> 31); | |
293 | accu = (int64_t)Q31(M_SQRT1_2)*(tmp3 - tmp4); | |
294 | tmp7 = (int32_t)((accu + 0x40000000) >> 31); | |
295 | accu = (int64_t)Q31(M_SQRT1_2)*(tmp2 - tmp1); | |
296 | tmp6 = (int32_t)((accu + 0x40000000) >> 31); | |
297 | accu = (int64_t)Q31(M_SQRT1_2)*(tmp3 + tmp4); | |
298 | tmp8 = (int32_t)((accu + 0x40000000) >> 31); | |
299 | tmp1 = tmp5 + tmp7; | |
300 | tmp3 = tmp5 - tmp7; | |
301 | tmp2 = tmp6 + tmp8; | |
302 | tmp4 = tmp6 - tmp8; | |
303 | ||
304 | tmpz[5].re = tmpz[1].re - tmp1; | |
305 | tmpz[1].re = tmpz[1].re + tmp1; | |
306 | tmpz[5].im = tmpz[1].im - tmp2; | |
307 | tmpz[1].im = tmpz[1].im + tmp2; | |
308 | tmpz[7].re = tmpz[3].re - tmp4; | |
309 | tmpz[3].re = tmpz[3].re + tmp4; | |
310 | tmpz[7].im = tmpz[3].im + tmp3; | |
311 | tmpz[3].im = tmpz[3].im - tmp3; | |
312 | } | |
313 | ||
314 | step = 1 << ((MAX_LOG2_NFFT-4) - 4); | |
315 | n4 = 4; | |
316 | ||
317 | for (nbits=4; nbits<=s->nbits; nbits++){ | |
318 | n2 = 2*n4; | |
319 | n34 = 3*n4; | |
320 | num_transforms = (num_transforms >> 1) | 1; | |
321 | ||
322 | for (n=0; n<num_transforms; n++){ | |
323 | const FFTSample *w_re_ptr = ff_w_tab_sr + step; | |
324 | const FFTSample *w_im_ptr = ff_w_tab_sr + MAX_FFT_SIZE/(4*16) - step; | |
325 | offset = ff_fft_offsets_lut[n] << nbits; | |
326 | tmpz = z + offset; | |
327 | ||
328 | tmp5 = tmpz[ n2].re + tmpz[n34].re; | |
329 | tmp1 = tmpz[ n2].re - tmpz[n34].re; | |
330 | tmp6 = tmpz[ n2].im + tmpz[n34].im; | |
331 | tmp2 = tmpz[ n2].im - tmpz[n34].im; | |
332 | ||
333 | tmpz[ n2].re = tmpz[ 0].re - tmp5; | |
334 | tmpz[ 0].re = tmpz[ 0].re + tmp5; | |
335 | tmpz[ n2].im = tmpz[ 0].im - tmp6; | |
336 | tmpz[ 0].im = tmpz[ 0].im + tmp6; | |
337 | tmpz[n34].re = tmpz[n4].re - tmp2; | |
338 | tmpz[ n4].re = tmpz[n4].re + tmp2; | |
339 | tmpz[n34].im = tmpz[n4].im + tmp1; | |
340 | tmpz[ n4].im = tmpz[n4].im - tmp1; | |
341 | ||
342 | for (i=1; i<n4; i++){ | |
343 | FFTSample w_re = w_re_ptr[0]; | |
344 | FFTSample w_im = w_im_ptr[0]; | |
345 | accu = (int64_t)w_re*tmpz[ n2+i].re; | |
346 | accu += (int64_t)w_im*tmpz[ n2+i].im; | |
347 | tmp1 = (int32_t)((accu + 0x40000000) >> 31); | |
348 | accu = (int64_t)w_re*tmpz[ n2+i].im; | |
349 | accu -= (int64_t)w_im*tmpz[ n2+i].re; | |
350 | tmp2 = (int32_t)((accu + 0x40000000) >> 31); | |
351 | accu = (int64_t)w_re*tmpz[n34+i].re; | |
352 | accu -= (int64_t)w_im*tmpz[n34+i].im; | |
353 | tmp3 = (int32_t)((accu + 0x40000000) >> 31); | |
354 | accu = (int64_t)w_re*tmpz[n34+i].im; | |
355 | accu += (int64_t)w_im*tmpz[n34+i].re; | |
356 | tmp4 = (int32_t)((accu + 0x40000000) >> 31); | |
357 | ||
358 | tmp5 = tmp1 + tmp3; | |
359 | tmp1 = tmp1 - tmp3; | |
360 | tmp6 = tmp2 + tmp4; | |
361 | tmp2 = tmp2 - tmp4; | |
362 | ||
363 | tmpz[ n2+i].re = tmpz[ i].re - tmp5; | |
364 | tmpz[ i].re = tmpz[ i].re + tmp5; | |
365 | tmpz[ n2+i].im = tmpz[ i].im - tmp6; | |
366 | tmpz[ i].im = tmpz[ i].im + tmp6; | |
367 | tmpz[n34+i].re = tmpz[n4+i].re - tmp2; | |
368 | tmpz[ n4+i].re = tmpz[n4+i].re + tmp2; | |
369 | tmpz[n34+i].im = tmpz[n4+i].im + tmp1; | |
370 | tmpz[ n4+i].im = tmpz[n4+i].im - tmp1; | |
371 | ||
372 | w_re_ptr += step; | |
373 | w_im_ptr -= step; | |
374 | } | |
375 | } | |
376 | step >>= 1; | |
377 | n4 <<= 1; | |
378 | } | |
379 | } | |
380 | ||
381 | #else /* FFT_FIXED_32 */ | |
382 | ||
383 | #define BUTTERFLIES(a0,a1,a2,a3) {\ | |
384 | BF(t3, t5, t5, t1);\ | |
385 | BF(a2.re, a0.re, a0.re, t5);\ | |
386 | BF(a3.im, a1.im, a1.im, t3);\ | |
387 | BF(t4, t6, t2, t6);\ | |
388 | BF(a3.re, a1.re, a1.re, t4);\ | |
389 | BF(a2.im, a0.im, a0.im, t6);\ | |
390 | } | |
391 | ||
392 | // force loading all the inputs before storing any. | |
393 | // this is slightly slower for small data, but avoids store->load aliasing | |
394 | // for addresses separated by large powers of 2. | |
395 | #define BUTTERFLIES_BIG(a0,a1,a2,a3) {\ | |
396 | FFTSample r0=a0.re, i0=a0.im, r1=a1.re, i1=a1.im;\ | |
397 | BF(t3, t5, t5, t1);\ | |
398 | BF(a2.re, a0.re, r0, t5);\ | |
399 | BF(a3.im, a1.im, i1, t3);\ | |
400 | BF(t4, t6, t2, t6);\ | |
401 | BF(a3.re, a1.re, r1, t4);\ | |
402 | BF(a2.im, a0.im, i0, t6);\ | |
403 | } | |
404 | ||
405 | #define TRANSFORM(a0,a1,a2,a3,wre,wim) {\ | |
406 | CMUL(t1, t2, a2.re, a2.im, wre, -wim);\ | |
407 | CMUL(t5, t6, a3.re, a3.im, wre, wim);\ | |
408 | BUTTERFLIES(a0,a1,a2,a3)\ | |
409 | } | |
410 | ||
411 | #define TRANSFORM_ZERO(a0,a1,a2,a3) {\ | |
412 | t1 = a2.re;\ | |
413 | t2 = a2.im;\ | |
414 | t5 = a3.re;\ | |
415 | t6 = a3.im;\ | |
416 | BUTTERFLIES(a0,a1,a2,a3)\ | |
417 | } | |
418 | ||
419 | /* z[0...8n-1], w[1...2n-1] */ | |
420 | #define PASS(name)\ | |
421 | static void name(FFTComplex *z, const FFTSample *wre, unsigned int n)\ | |
422 | {\ | |
423 | FFTDouble t1, t2, t3, t4, t5, t6;\ | |
424 | int o1 = 2*n;\ | |
425 | int o2 = 4*n;\ | |
426 | int o3 = 6*n;\ | |
427 | const FFTSample *wim = wre+o1;\ | |
428 | n--;\ | |
429 | \ | |
430 | TRANSFORM_ZERO(z[0],z[o1],z[o2],z[o3]);\ | |
431 | TRANSFORM(z[1],z[o1+1],z[o2+1],z[o3+1],wre[1],wim[-1]);\ | |
432 | do {\ | |
433 | z += 2;\ | |
434 | wre += 2;\ | |
435 | wim -= 2;\ | |
436 | TRANSFORM(z[0],z[o1],z[o2],z[o3],wre[0],wim[0]);\ | |
437 | TRANSFORM(z[1],z[o1+1],z[o2+1],z[o3+1],wre[1],wim[-1]);\ | |
438 | } while(--n);\ | |
439 | } | |
440 | ||
441 | PASS(pass) | |
442 | #undef BUTTERFLIES | |
443 | #define BUTTERFLIES BUTTERFLIES_BIG | |
444 | PASS(pass_big) | |
445 | ||
446 | #define DECL_FFT(n,n2,n4)\ | |
447 | static void fft##n(FFTComplex *z)\ | |
448 | {\ | |
449 | fft##n2(z);\ | |
450 | fft##n4(z+n4*2);\ | |
451 | fft##n4(z+n4*3);\ | |
452 | pass(z,FFT_NAME(ff_cos_##n),n4/2);\ | |
453 | } | |
454 | ||
455 | static void fft4(FFTComplex *z) | |
456 | { | |
457 | FFTDouble t1, t2, t3, t4, t5, t6, t7, t8; | |
458 | ||
459 | BF(t3, t1, z[0].re, z[1].re); | |
460 | BF(t8, t6, z[3].re, z[2].re); | |
461 | BF(z[2].re, z[0].re, t1, t6); | |
462 | BF(t4, t2, z[0].im, z[1].im); | |
463 | BF(t7, t5, z[2].im, z[3].im); | |
464 | BF(z[3].im, z[1].im, t4, t8); | |
465 | BF(z[3].re, z[1].re, t3, t7); | |
466 | BF(z[2].im, z[0].im, t2, t5); | |
467 | } | |
468 | ||
469 | static void fft8(FFTComplex *z) | |
470 | { | |
471 | FFTDouble t1, t2, t3, t4, t5, t6; | |
472 | ||
473 | fft4(z); | |
474 | ||
475 | BF(t1, z[5].re, z[4].re, -z[5].re); | |
476 | BF(t2, z[5].im, z[4].im, -z[5].im); | |
477 | BF(t5, z[7].re, z[6].re, -z[7].re); | |
478 | BF(t6, z[7].im, z[6].im, -z[7].im); | |
479 | ||
480 | BUTTERFLIES(z[0],z[2],z[4],z[6]); | |
481 | TRANSFORM(z[1],z[3],z[5],z[7],sqrthalf,sqrthalf); | |
482 | } | |
483 | ||
484 | #if !CONFIG_SMALL | |
485 | static void fft16(FFTComplex *z) | |
486 | { | |
487 | FFTDouble t1, t2, t3, t4, t5, t6; | |
488 | FFTSample cos_16_1 = FFT_NAME(ff_cos_16)[1]; | |
489 | FFTSample cos_16_3 = FFT_NAME(ff_cos_16)[3]; | |
490 | ||
491 | fft8(z); | |
492 | fft4(z+8); | |
493 | fft4(z+12); | |
494 | ||
495 | TRANSFORM_ZERO(z[0],z[4],z[8],z[12]); | |
496 | TRANSFORM(z[2],z[6],z[10],z[14],sqrthalf,sqrthalf); | |
497 | TRANSFORM(z[1],z[5],z[9],z[13],cos_16_1,cos_16_3); | |
498 | TRANSFORM(z[3],z[7],z[11],z[15],cos_16_3,cos_16_1); | |
499 | } | |
500 | #else | |
501 | DECL_FFT(16,8,4) | |
502 | #endif | |
503 | DECL_FFT(32,16,8) | |
504 | DECL_FFT(64,32,16) | |
505 | DECL_FFT(128,64,32) | |
506 | DECL_FFT(256,128,64) | |
507 | DECL_FFT(512,256,128) | |
508 | #if !CONFIG_SMALL | |
509 | #define pass pass_big | |
510 | #endif | |
511 | DECL_FFT(1024,512,256) | |
512 | DECL_FFT(2048,1024,512) | |
513 | DECL_FFT(4096,2048,1024) | |
514 | DECL_FFT(8192,4096,2048) | |
515 | DECL_FFT(16384,8192,4096) | |
516 | DECL_FFT(32768,16384,8192) | |
517 | DECL_FFT(65536,32768,16384) | |
518 | ||
519 | static void (* const fft_dispatch[])(FFTComplex*) = { | |
520 | fft4, fft8, fft16, fft32, fft64, fft128, fft256, fft512, fft1024, | |
521 | fft2048, fft4096, fft8192, fft16384, fft32768, fft65536, | |
522 | }; | |
523 | ||
524 | static void fft_calc_c(FFTContext *s, FFTComplex *z) | |
525 | { | |
526 | fft_dispatch[s->nbits-2](z); | |
527 | } | |
528 | #endif /* FFT_FIXED_32 */ |