Line data Source code
1 : /*
2 : * Xvid MPEG-4 IDCT
3 : *
4 : * Copyright (C) 2006-2011 Xvid Solutions GmbH
5 : *
6 : * This file is part of FFmpeg.
7 : *
8 : * FFmpeg is free software; you can redistribute it and/or
9 : * modify it under the terms of the GNU Lesser General Public
10 : * License as published by the Free Software Foundation; either
11 : * version 2.1 of the License, or (at your option) any later version.
12 : *
13 : * FFmpeg is distributed in the hope that it will be useful,
14 : * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 : * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 : * Lesser General Public License for more details.
17 : *
18 : * You should have received a copy of the GNU Lesser General Public
19 : * License along with FFmpeg; if not, write to the Free Software
20 : * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 : */
22 :
23 : /**
24 : * @file
25 : * Walken IDCT
26 : * Alternative IDCT implementation for decoding compatibility.
27 : *
28 : * @author Skal
29 : * @note This C version is not the original IDCT, but a modified one that
30 : * yields the same error profile as the MMX/MMXEXT/SSE2 versions.
31 : */
32 :
33 : #include "config.h"
34 : #include "libavutil/attributes.h"
35 : #include "avcodec.h"
36 : #include "idctdsp.h"
37 : #include "xvididct.h"
38 :
39 : #define ROW_SHIFT 11
40 : #define COL_SHIFT 6
41 :
42 : // #define FIX(x) (int)((x) * (1 << ROW_SHIFT))
43 : #define RND0 65536 // 1 << (COL_SHIFT + ROW_SHIFT - 1);
44 : #define RND1 3597 // FIX (1.75683487303);
45 : #define RND2 2260 // FIX (1.10355339059);
46 : #define RND3 1203 // FIX (0.587788325588);
47 : #define RND4 0
48 : #define RND5 120 // FIX (0.058658283817);
49 : #define RND6 512 // FIX (0.25);
50 : #define RND7 512 // FIX (0.25);
51 :
52 : static const int TAB04[] = { 22725, 21407, 19266, 16384, 12873, 8867, 4520 };
53 : static const int TAB17[] = { 31521, 29692, 26722, 22725, 17855, 12299, 6270 };
54 : static const int TAB26[] = { 29692, 27969, 25172, 21407, 16819, 11585, 5906 };
55 : static const int TAB35[] = { 26722, 25172, 22654, 19266, 15137, 10426, 5315 };
56 :
57 480000 : static int idct_row(short *in, const int *const tab, int rnd)
58 : {
59 480000 : const int c1 = tab[0];
60 480000 : const int c2 = tab[1];
61 480000 : const int c3 = tab[2];
62 480000 : const int c4 = tab[3];
63 480000 : const int c5 = tab[4];
64 480000 : const int c6 = tab[5];
65 480000 : const int c7 = tab[6];
66 :
67 480000 : const int right = in[5] | in[6] | in[7];
68 480000 : const int left = in[1] | in[2] | in[3];
69 480000 : if (!(right | in[4])) {
70 264353 : const int k = c4 * in[0] + rnd;
71 264353 : if (left) {
72 24730 : const int a0 = k + c2 * in[2];
73 24730 : const int a1 = k + c6 * in[2];
74 24730 : const int a2 = k - c6 * in[2];
75 24730 : const int a3 = k - c2 * in[2];
76 :
77 24730 : const int b0 = c1 * in[1] + c3 * in[3];
78 24730 : const int b1 = c3 * in[1] - c7 * in[3];
79 24730 : const int b2 = c5 * in[1] - c1 * in[3];
80 24730 : const int b3 = c7 * in[1] - c5 * in[3];
81 :
82 24730 : in[0] = (a0 + b0) >> ROW_SHIFT;
83 24730 : in[1] = (a1 + b1) >> ROW_SHIFT;
84 24730 : in[2] = (a2 + b2) >> ROW_SHIFT;
85 24730 : in[3] = (a3 + b3) >> ROW_SHIFT;
86 24730 : in[4] = (a3 - b3) >> ROW_SHIFT;
87 24730 : in[5] = (a2 - b2) >> ROW_SHIFT;
88 24730 : in[6] = (a1 - b1) >> ROW_SHIFT;
89 24730 : in[7] = (a0 - b0) >> ROW_SHIFT;
90 : } else {
91 239623 : const int a0 = k >> ROW_SHIFT;
92 239623 : if (a0) {
93 97939 : in[0] =
94 195878 : in[1] =
95 293817 : in[2] =
96 293817 : in[3] =
97 293817 : in[4] =
98 293817 : in[5] =
99 293817 : in[6] =
100 195878 : in[7] = a0;
101 : } else
102 141684 : return 0;
103 : }
104 215647 : } else if (!(left | right)) {
105 7429 : const int a0 = (rnd + c4 * (in[0] + in[4])) >> ROW_SHIFT;
106 7429 : const int a1 = (rnd + c4 * (in[0] - in[4])) >> ROW_SHIFT;
107 :
108 7429 : in[0] = a0;
109 7429 : in[3] = a0;
110 7429 : in[4] = a0;
111 7429 : in[7] = a0;
112 7429 : in[1] = a1;
113 7429 : in[2] = a1;
114 7429 : in[5] = a1;
115 7429 : in[6] = a1;
116 : } else {
117 208218 : const int k = c4 * in[0] + rnd;
118 208218 : const int a0 = k + c2 * in[2] + c4 * in[4] + c6 * in[6];
119 208218 : const int a1 = k + c6 * in[2] - c4 * in[4] - c2 * in[6];
120 208218 : const int a2 = k - c6 * in[2] - c4 * in[4] + c2 * in[6];
121 208218 : const int a3 = k - c2 * in[2] + c4 * in[4] - c6 * in[6];
122 :
123 208218 : const int b0 = c1 * in[1] + c3 * in[3] + c5 * in[5] + c7 * in[7];
124 208218 : const int b1 = c3 * in[1] - c7 * in[3] - c1 * in[5] - c5 * in[7];
125 208218 : const int b2 = c5 * in[1] - c1 * in[3] + c7 * in[5] + c3 * in[7];
126 208218 : const int b3 = c7 * in[1] - c5 * in[3] + c3 * in[5] - c1 * in[7];
127 :
128 208218 : in[0] = (a0 + b0) >> ROW_SHIFT;
129 208218 : in[1] = (a1 + b1) >> ROW_SHIFT;
130 208218 : in[2] = (a2 + b2) >> ROW_SHIFT;
131 208218 : in[3] = (a3 + b3) >> ROW_SHIFT;
132 208218 : in[4] = (a3 - b3) >> ROW_SHIFT;
133 208218 : in[5] = (a2 - b2) >> ROW_SHIFT;
134 208218 : in[6] = (a1 - b1) >> ROW_SHIFT;
135 208218 : in[7] = (a0 - b0) >> ROW_SHIFT;
136 : }
137 338316 : return 1;
138 : }
139 :
140 : #define TAN1 0x32EC
141 : #define TAN2 0x6A0A
142 : #define TAN3 0xAB0E
143 : #define SQRT2 0x5A82
144 :
145 : #define MULT(c, x, n) (((c) * (x)) >> (n))
146 : // 12b version => #define MULT(c,x, n) ((((c) >> 3) * (x)) >> ((n) - 3))
147 : // 12b zero-testing version:
148 :
149 : #define BUTTERFLY(a, b, tmp) \
150 : (tmp) = (a) + (b); \
151 : (b) = (a) - (b); \
152 : (a) = (tmp)
153 :
154 : #define LOAD_BUTTERFLY(m1, m2, a, b, tmp, s) \
155 : (m1) = (s)[(a)] + (s)[(b)]; \
156 : (m2) = (s)[(a)] - (s)[(b)]
157 :
158 384504 : static void idct_col_8(short *const in)
159 : {
160 : int mm0, mm1, mm2, mm3, mm4, mm5, mm6, mm7, spill;
161 :
162 : // odd
163 :
164 384504 : mm4 = (int) in[7 * 8];
165 384504 : mm5 = (int) in[5 * 8];
166 384504 : mm6 = (int) in[3 * 8];
167 384504 : mm7 = (int) in[1 * 8];
168 :
169 384504 : mm0 = MULT(TAN1, mm4, 16) + mm7;
170 384504 : mm1 = MULT(TAN1, mm7, 16) - mm4;
171 384504 : mm2 = MULT(TAN3, mm5, 16) + mm6;
172 384504 : mm3 = MULT(TAN3, mm6, 16) - mm5;
173 :
174 384504 : mm7 = mm0 + mm2;
175 384504 : mm4 = mm1 - mm3;
176 384504 : mm0 = mm0 - mm2;
177 384504 : mm1 = mm1 + mm3;
178 384504 : mm6 = mm0 + mm1;
179 384504 : mm5 = mm0 - mm1;
180 384504 : mm5 = 2 * MULT(SQRT2, mm5, 16); // 2*sqrt2
181 384504 : mm6 = 2 * MULT(SQRT2, mm6, 16); // Watch out: precision loss but done to match
182 : // the pmulhw used in MMX/MMXEXT/SSE2 versions
183 :
184 : // even
185 :
186 384504 : mm1 = (int) in[2 * 8];
187 384504 : mm2 = (int) in[6 * 8];
188 384504 : mm3 = MULT(TAN2, mm2, 16) + mm1;
189 384504 : mm2 = MULT(TAN2, mm1, 16) - mm2;
190 :
191 384504 : LOAD_BUTTERFLY(mm0, mm1, 0 * 8, 4 * 8, spill, in);
192 :
193 384504 : BUTTERFLY(mm0, mm3, spill);
194 384504 : BUTTERFLY(mm0, mm7, spill);
195 384504 : in[8 * 0] = (int16_t) (mm0 >> COL_SHIFT);
196 384504 : in[8 * 7] = (int16_t) (mm7 >> COL_SHIFT);
197 384504 : BUTTERFLY(mm3, mm4, mm0);
198 384504 : in[8 * 3] = (int16_t) (mm3 >> COL_SHIFT);
199 384504 : in[8 * 4] = (int16_t) (mm4 >> COL_SHIFT);
200 :
201 384504 : BUTTERFLY(mm1, mm2, mm0);
202 384504 : BUTTERFLY(mm1, mm6, mm0);
203 384504 : in[8 * 1] = (int16_t) (mm1 >> COL_SHIFT);
204 384504 : in[8 * 6] = (int16_t) (mm6 >> COL_SHIFT);
205 384504 : BUTTERFLY(mm2, mm5, mm0);
206 384504 : in[8 * 2] = (int16_t) (mm2 >> COL_SHIFT);
207 384504 : in[8 * 5] = (int16_t) (mm5 >> COL_SHIFT);
208 384504 : }
209 :
210 5896 : static void idct_col_4(short *const in)
211 : {
212 : int mm0, mm1, mm2, mm3, mm4, mm5, mm6, mm7, spill;
213 :
214 : // odd
215 :
216 5896 : mm0 = (int) in[1 * 8];
217 5896 : mm2 = (int) in[3 * 8];
218 :
219 5896 : mm1 = MULT(TAN1, mm0, 16);
220 5896 : mm3 = MULT(TAN3, mm2, 16);
221 :
222 5896 : mm7 = mm0 + mm2;
223 5896 : mm4 = mm1 - mm3;
224 5896 : mm0 = mm0 - mm2;
225 5896 : mm1 = mm1 + mm3;
226 5896 : mm6 = mm0 + mm1;
227 5896 : mm5 = mm0 - mm1;
228 5896 : mm6 = 2 * MULT(SQRT2, mm6, 16); // 2*sqrt2
229 5896 : mm5 = 2 * MULT(SQRT2, mm5, 16);
230 :
231 : // even
232 :
233 5896 : mm0 = mm1 = (int) in[0 * 8];
234 5896 : mm3 = (int) in[2 * 8];
235 5896 : mm2 = MULT(TAN2, mm3, 16);
236 :
237 5896 : BUTTERFLY(mm0, mm3, spill);
238 5896 : BUTTERFLY(mm0, mm7, spill);
239 5896 : in[8 * 0] = (int16_t) (mm0 >> COL_SHIFT);
240 5896 : in[8 * 7] = (int16_t) (mm7 >> COL_SHIFT);
241 5896 : BUTTERFLY(mm3, mm4, mm0);
242 5896 : in[8 * 3] = (int16_t) (mm3 >> COL_SHIFT);
243 5896 : in[8 * 4] = (int16_t) (mm4 >> COL_SHIFT);
244 :
245 5896 : BUTTERFLY(mm1, mm2, mm0);
246 5896 : BUTTERFLY(mm1, mm6, mm0);
247 5896 : in[8 * 1] = (int16_t) (mm1 >> COL_SHIFT);
248 5896 : in[8 * 6] = (int16_t) (mm6 >> COL_SHIFT);
249 5896 : BUTTERFLY(mm2, mm5, mm0);
250 5896 : in[8 * 2] = (int16_t) (mm2 >> COL_SHIFT);
251 5896 : in[8 * 5] = (int16_t) (mm5 >> COL_SHIFT);
252 5896 : }
253 :
254 89600 : static void idct_col_3(short *const in)
255 : {
256 : int mm0, mm1, mm2, mm3, mm4, mm5, mm6, mm7, spill;
257 :
258 : // odd
259 :
260 89600 : mm7 = (int) in[1 * 8];
261 89600 : mm4 = MULT(TAN1, mm7, 16);
262 :
263 89600 : mm6 = mm7 + mm4;
264 89600 : mm5 = mm7 - mm4;
265 89600 : mm6 = 2 * MULT(SQRT2, mm6, 16); // 2*sqrt2
266 89600 : mm5 = 2 * MULT(SQRT2, mm5, 16);
267 :
268 : // even
269 :
270 89600 : mm0 = mm1 = (int) in[0 * 8];
271 89600 : mm3 = (int) in[2 * 8];
272 89600 : mm2 = MULT(TAN2, mm3, 16);
273 :
274 89600 : BUTTERFLY(mm0, mm3, spill);
275 89600 : BUTTERFLY(mm0, mm7, spill);
276 89600 : in[8 * 0] = (int16_t) (mm0 >> COL_SHIFT);
277 89600 : in[8 * 7] = (int16_t) (mm7 >> COL_SHIFT);
278 89600 : BUTTERFLY(mm3, mm4, mm0);
279 89600 : in[8 * 3] = (int16_t) (mm3 >> COL_SHIFT);
280 89600 : in[8 * 4] = (int16_t) (mm4 >> COL_SHIFT);
281 :
282 89600 : BUTTERFLY(mm1, mm2, mm0);
283 89600 : BUTTERFLY(mm1, mm6, mm0);
284 89600 : in[8 * 1] = (int16_t) (mm1 >> COL_SHIFT);
285 89600 : in[8 * 6] = (int16_t) (mm6 >> COL_SHIFT);
286 89600 : BUTTERFLY(mm2, mm5, mm0);
287 89600 : in[8 * 2] = (int16_t) (mm2 >> COL_SHIFT);
288 89600 : in[8 * 5] = (int16_t) (mm5 >> COL_SHIFT);
289 89600 : }
290 :
291 60000 : void ff_xvid_idct(int16_t *const in)
292 : {
293 60000 : int i, rows = 0x07;
294 :
295 60000 : idct_row(in + 0 * 8, TAB04, RND0);
296 60000 : idct_row(in + 1 * 8, TAB17, RND1);
297 60000 : idct_row(in + 2 * 8, TAB26, RND2);
298 60000 : if (idct_row(in + 3 * 8, TAB35, RND3))
299 29558 : rows |= 0x08;
300 60000 : if (idct_row(in + 4 * 8, TAB04, RND4))
301 29661 : rows |= 0x10;
302 60000 : if (idct_row(in + 5 * 8, TAB35, RND5))
303 29720 : rows |= 0x20;
304 60000 : if (idct_row(in + 6 * 8, TAB26, RND6))
305 29731 : rows |= 0x40;
306 60000 : if (idct_row(in + 7 * 8, TAB17, RND7))
307 39653 : rows |= 0x80;
308 :
309 60000 : if (rows & 0xF0) {
310 432567 : for (i = 0; i < 8; i++)
311 384504 : idct_col_8(in + i);
312 11937 : } else if (rows & 0x08) {
313 6633 : for (i = 0; i < 8; i++)
314 5896 : idct_col_4(in + i);
315 : } else {
316 100800 : for (i = 0; i < 8; i++)
317 89600 : idct_col_3(in + i);
318 : }
319 60000 : }
320 :
321 0 : static void xvid_idct_put(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
322 : {
323 0 : ff_xvid_idct(block);
324 0 : ff_put_pixels_clamped_c(block, dest, line_size);
325 0 : }
326 :
327 0 : static void xvid_idct_add(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
328 : {
329 0 : ff_xvid_idct(block);
330 0 : ff_add_pixels_clamped_c(block, dest, line_size);
331 0 : }
332 :
333 4 : av_cold void ff_xvid_idct_init(IDCTDSPContext *c, AVCodecContext *avctx)
334 : {
335 4 : const unsigned high_bit_depth = avctx->bits_per_raw_sample > 8;
336 :
337 8 : if (high_bit_depth || avctx->lowres ||
338 8 : !(avctx->idct_algo == FF_IDCT_AUTO ||
339 4 : avctx->idct_algo == FF_IDCT_XVID))
340 0 : return;
341 :
342 4 : if (avctx->idct_algo == FF_IDCT_XVID) {
343 4 : c->idct_put = xvid_idct_put;
344 4 : c->idct_add = xvid_idct_add;
345 4 : c->idct = ff_xvid_idct;
346 4 : c->perm_type = FF_IDCT_PERM_NONE;
347 : }
348 :
349 : if (ARCH_X86)
350 4 : ff_xvid_idct_init_x86(c, avctx, high_bit_depth);
351 : if (ARCH_MIPS)
352 : ff_xvid_idct_init_mips(c, avctx, high_bit_depth);
353 :
354 4 : ff_init_scantable_permutation(c->idct_permutation, c->perm_type);
355 : }
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