GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/xvididct.c Lines: 198 205 96.6 %
Date: 2020-08-14 10:39:37 Branches: 33 38 86.8 %

Line Branch Exec Source
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
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 * 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
97939
                in[1] =
95
97939
                in[2] =
96
97939
                in[3] =
97
97939
                in[4] =
98
97939
                in[5] =
99
97939
                in[6] =
100
97939
                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 unsigned int a0 = k + c2 * in[2] + c4 * in[4] + c6 * in[6];
119
208218
        const unsigned int a1 = k + c6 * in[2] - c4 * in[4] - c2 * in[6];
120
208218
        const unsigned int a2 = k - c6 * in[2] - c4 * in[4] + c2 * in[6];
121
208218
        const unsigned int a3 = k - c2 * in[2] + c4 * in[4] - c6 * in[6];
122
123
208218
        const unsigned int b0 = c1 * in[1] + c3 * in[3] + c5 * in[5] + c7 * in[7];
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208218
        const unsigned int b1 = c3 * in[1] - c7 * in[3] - c1 * in[5] - c5 * in[7];
125
208218
        const unsigned int b2 = c5 * in[1] - c1 * in[3] + c7 * in[5] + c3 * in[7];
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208218
        const unsigned int b3 = c7 * in[1] - c5 * in[3] + c3 * in[5] - c1 * in[7];
127
128
208218
        in[0] = (int)(a0 + b0) >> ROW_SHIFT;
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208218
        in[1] = (int)(a1 + b1) >> ROW_SHIFT;
130
208218
        in[2] = (int)(a2 + b2) >> ROW_SHIFT;
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208218
        in[3] = (int)(a3 + b3) >> ROW_SHIFT;
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208218
        in[4] = (int)(a3 - b3) >> ROW_SHIFT;
133
208218
        in[5] = (int)(a2 - b2) >> ROW_SHIFT;
134
208218
        in[6] = (int)(a1 - b1) >> ROW_SHIFT;
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208218
        in[7] = (int)(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)  ((unsigned)((int)((c) * (unsigned)(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
static void xvid_idct_put(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
322
{
323
    ff_xvid_idct(block);
324
    ff_put_pixels_clamped_c(block, dest, line_size);
325
}
326
327
static void xvid_idct_add(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
328
{
329
    ff_xvid_idct(block);
330
    ff_add_pixels_clamped_c(block, dest, line_size);
331
}
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

4
    if (high_bit_depth || avctx->lowres ||
338
4
        !(avctx->idct_algo == FF_IDCT_AUTO ||
339
4
          avctx->idct_algo == FF_IDCT_XVID))
340
        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
}