FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/simple_idct.c
Date: 2026-01-16 07:34:38
Exec Total Coverage
Lines: 78 84 92.9%
Functions: 6 7 85.7%
Branches: 14 18 77.8%
Line Branch Exec Source
1 /*
2 * Simple IDCT
3 *
4 * Copyright (c) 2001 Michael Niedermayer <michaelni@gmx.at>
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 * simpleidct in C.
26 */
27
28 #include "libavutil/intreadwrite.h"
29 #include "mathops.h"
30 #include "simple_idct.h"
31
32 #define IN_IDCT_DEPTH 16
33
34 #define BIT_DEPTH 8
35 #include "simple_idct_template.c"
36 #undef BIT_DEPTH
37
38 #define BIT_DEPTH 10
39 #include "simple_idct_template.c"
40 #undef BIT_DEPTH
41
42 #define BIT_DEPTH 12
43 #include "simple_idct_template.c"
44 #undef BIT_DEPTH
45 #undef IN_IDCT_DEPTH
46
47 #define IN_IDCT_DEPTH 32
48 #define BIT_DEPTH 10
49 #include "simple_idct_template.c"
50 #undef BIT_DEPTH
51 #undef IN_IDCT_DEPTH
52
53 /* 2x4x8 idct */
54
55 #define CN_SHIFT 12
56 #define C_FIX(x) ((int)((x) * (1 << CN_SHIFT) + 0.5))
57 #define C1 C_FIX(0.6532814824)
58 #define C2 C_FIX(0.2705980501)
59
60 /* row idct is multiple by 16 * sqrt(2.0), col idct4 is normalized,
61 and the butterfly must be multiplied by 0.5 * sqrt(2.0) */
62 #define C_SHIFT (4+1+12)
63
64 441216 static inline void idct4col_put(uint8_t *dest, ptrdiff_t line_size, const int16_t *col)
65 {
66 int c0, c1, c2, c3, a0, a1, a2, a3;
67
68 441216 a0 = col[8*0];
69 441216 a1 = col[8*2];
70 441216 a2 = col[8*4];
71 441216 a3 = col[8*6];
72 441216 c0 = ((a0 + a2) * (1 << CN_SHIFT - 1)) + (1 << (C_SHIFT - 1));
73 441216 c2 = ((a0 - a2) * (1 << CN_SHIFT - 1)) + (1 << (C_SHIFT - 1));
74 441216 c1 = a1 * C1 + a3 * C2;
75 441216 c3 = a1 * C2 - a3 * C1;
76 441216 dest[0] = av_clip_uint8((c0 + c1) >> C_SHIFT);
77 441216 dest += line_size;
78 441216 dest[0] = av_clip_uint8((c2 + c3) >> C_SHIFT);
79 441216 dest += line_size;
80 441216 dest[0] = av_clip_uint8((c2 - c3) >> C_SHIFT);
81 441216 dest += line_size;
82 441216 dest[0] = av_clip_uint8((c0 - c1) >> C_SHIFT);
83 441216 }
84
85 #define BF(k) \
86 {\
87 int a0, a1;\
88 a0 = ptr[k];\
89 a1 = ptr[8 + k];\
90 ptr[k] = a0 + a1;\
91 ptr[8 + k] = a0 - a1;\
92 }
93
94 /* only used by DV codec. The input must be interlaced. 128 is added
95 to the pixels before clamping to avoid systematic error
96 (1024*sqrt(2)) offset would be needed otherwise. */
97 /* XXX: I think a 1.0/sqrt(2) normalization should be needed to
98 compensate the extra butterfly stage - I don't have the full DV
99 specification */
100 27576 void ff_simple_idct248_put(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
101 {
102 int i;
103 int16_t *ptr;
104
105 /* butterfly */
106 27576 ptr = block;
107
2/2
✓ Branch 0 taken 110304 times.
✓ Branch 1 taken 27576 times.
 137880 for(i=0;i<4;i++) {
108 110304 BF(0);
109 110304 BF(1);
110 110304 BF(2);
111 110304 BF(3);
112 110304 BF(4);
113 110304 BF(5);
114 110304 BF(6);
115 110304 BF(7);
116 110304 ptr += 2 * 8;
117 }
118
119 /* IDCT8 on each line */
120
2/2
✓ Branch 0 taken 220608 times.
✓ Branch 1 taken 27576 times.
 248184 for(i=0; i<8; i++) {
121 220608 idctRowCondDC_int16_8bit(block + i*8, 0);
122 }
123
124 /* IDCT4 and store */
125
2/2
✓ Branch 0 taken 220608 times.
✓ Branch 1 taken 27576 times.
 248184 for(i=0;i<8;i++) {
126 220608 idct4col_put(dest + i, 2 * line_size, block + i);
127 220608 idct4col_put(dest + line_size + i, 2 * line_size, block + 8 + i);
128 }
129 27576 }
130
131 /* 8x4 & 4x8 WMV2 IDCT */
132 #undef CN_SHIFT
133 #undef C_SHIFT
134 #undef C_FIX
135 #undef C1
136 #undef C2
137 #define CN_SHIFT 12
138 #define C_FIX(x) ((int)((x) * M_SQRT2 * (1 << CN_SHIFT) + 0.5))
139 #define C1 C_FIX(0.6532814824)
140 #define C2 C_FIX(0.2705980501)
141 #define C3 C_FIX(0.5)
142 #define C_SHIFT (4+1+12)
143 263504 static inline void idct4col_add(uint8_t *dest, ptrdiff_t line_size, const int16_t *col)
144 {
145 int c0, c1, c2, c3, a0, a1, a2, a3;
146
147 263504 a0 = col[8*0];
148 263504 a1 = col[8*1];
149 263504 a2 = col[8*2];
150 263504 a3 = col[8*3];
151 263504 c0 = (a0 + a2)*C3 + (1 << (C_SHIFT - 1));
152 263504 c2 = (a0 - a2)*C3 + (1 << (C_SHIFT - 1));
153 263504 c1 = a1 * C1 + a3 * C2;
154 263504 c3 = a1 * C2 - a3 * C1;
155 263504 dest[0] = av_clip_uint8(dest[0] + ((c0 + c1) >> C_SHIFT));
156 263504 dest += line_size;
157 263504 dest[0] = av_clip_uint8(dest[0] + ((c2 + c3) >> C_SHIFT));
158 263504 dest += line_size;
159 263504 dest[0] = av_clip_uint8(dest[0] + ((c2 - c3) >> C_SHIFT));
160 263504 dest += line_size;
161 263504 dest[0] = av_clip_uint8(dest[0] + ((c0 - c1) >> C_SHIFT));
162 263504 }
163
164 #define RN_SHIFT 15
165 #define R_FIX(x) ((int)((x) * M_SQRT2 * (1 << RN_SHIFT) + 0.5))
166 #define R1 R_FIX(0.6532814824)
167 #define R2 R_FIX(0.2705980501)
168 #define R3 R_FIX(0.5)
169 #define R_SHIFT 11
170 239648 static inline void idct4row(int16_t *row)
171 {
172 unsigned c0, c1, c2, c3;
173 int a0, a1, a2, a3;
174
175 239648 a0 = row[0];
176 239648 a1 = row[1];
177 239648 a2 = row[2];
178 239648 a3 = row[3];
179 239648 c0 = (a0 + a2)*R3 + (1 << (R_SHIFT - 1));
180 239648 c2 = (a0 - a2)*R3 + (1 << (R_SHIFT - 1));
181 239648 c1 = a1 * R1 + a3 * R2;
182 239648 c3 = a1 * R2 - a3 * R1;
183 239648 row[0]= (c0 + c1) >> R_SHIFT;
184 239648 row[1]= (c2 + c3) >> R_SHIFT;
185 239648 row[2]= (c2 - c3) >> R_SHIFT;
186 239648 row[3]= (c0 - c1) >> R_SHIFT;
187 239648 }
188
189 32938 void ff_simple_idct84_add(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
190 {
191 int i;
192
193 /* IDCT8 on each line */
194
2/2
✓ Branch 0 taken 131752 times.
✓ Branch 1 taken 32938 times.
 164690 for(i=0; i<4; i++) {
195 131752 idctRowCondDC_int16_8bit(block + i*8, 0);
196 }
197
198 /* IDCT4 and store */
199
2/2
✓ Branch 0 taken 263504 times.
✓ Branch 1 taken 32938 times.
 296442 for(i=0;i<8;i++) {
200 263504 idct4col_add(dest + i, line_size, block + i);
201 }
202 32938 }
203
204 29956 void ff_simple_idct48_add(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
205 {
206 int i;
207
208 /* IDCT4 on each line */
209
2/2
✓ Branch 0 taken 239648 times.
✓ Branch 1 taken 29956 times.
 269604 for(i=0; i<8; i++) {
210 239648 idct4row(block + i*8);
211 }
212
213 /* IDCT8 and store */
214
2/2
✓ Branch 0 taken 119824 times.
✓ Branch 1 taken 29956 times.
 149780 for(i=0; i<4; i++){
215 119824 idctSparseColAdd_int16_8bit(dest + i, line_size, block + i);
216 }
217 29956 }
218
219 ✗ void ff_simple_idct44_add(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
220 {
221 int i;
222
223 /* IDCT4 on each line */
224 ✗ for(i=0; i<4; i++) {
225 ✗ idct4row(block + i*8);
226 }
227
228 /* IDCT4 and store */
229 ✗ for(i=0; i<4; i++){
230 ✗ idct4col_add(dest + i, line_size, block + i);
231 }
232 ✗ }
233