FFmpeg
hq_hqadsp.c
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1 /*
2  * Canopus HQ/HQA decoder
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include <stdint.h>
22 
23 #include "libavutil/attributes.h"
24 #include "libavutil/common.h"
25 
26 #include "hq_hqadsp.h"
27 
28 #define FIX_1_082 17734
29 #define FIX_1_847 30274
30 #define FIX_1_414 23170
31 #define FIX_2_613 21407 // divided by two to fit the range
32 
33 #define IDCTMUL(a, b) ((int)((a) * (unsigned)(b)) >> 16)
34 
35 static inline void idct_row(int16_t *blk)
36 {
37  int tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, tmp8, tmp9, tmpA;
38  int tmpB, tmpC, tmpD, tmpE, tmpF, tmp10, tmp11, tmp12, tmp13, tmp14;
39 
40  tmp0 = blk[5] - blk[3];
41  tmp1 = blk[5] + blk[3];
42  tmp2 = blk[1] - blk[7];
43  tmp3 = blk[1] + blk[7];
44  tmp4 = tmp3 - tmp1;
45  tmp5 = IDCTMUL(tmp0 + tmp2, FIX_1_847);
46  tmp6 = IDCTMUL(tmp2, FIX_1_082) - tmp5;
47  tmp7 = tmp5 - IDCTMUL(tmp0, FIX_2_613) * 2;
48  tmp8 = tmp3 + tmp1;
49  tmp9 = tmp7 * 4 - tmp8;
50  tmpA = IDCTMUL(tmp4, FIX_1_414) * 4 - tmp9;
51  tmpB = tmp6 * 4 + tmpA;
52  tmpC = blk[2] + blk[6];
53  tmpD = blk[2] - blk[6];
54  tmpE = blk[0] - blk[4];
55  tmpF = blk[0] + blk[4];
56 
57  tmp10 = IDCTMUL(tmpD, FIX_1_414) * 4 - tmpC;
58  tmp11 = tmpE - tmp10;
59  tmp12 = tmpF - tmpC;
60  tmp13 = tmpE + tmp10;
61  tmp14 = tmpF + tmpC;
62 
63  blk[0] = tmp14 + tmp8;
64  blk[1] = tmp13 + tmp9;
65  blk[2] = tmp11 + tmpA;
66  blk[3] = tmp12 - tmpB;
67  blk[4] = tmp12 + tmpB;
68  blk[5] = tmp11 - tmpA;
69  blk[6] = tmp13 - tmp9;
70  blk[7] = tmp14 - tmp8;
71 }
72 
73 static inline void idct_col(int16_t *blk)
74 {
75  int tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, tmp8, tmp9, tmpA;
76  int tmpB, tmpC, tmpD, tmpE, tmpF, tmp10, tmp11, tmp12, tmp13, tmp14;
77 
78  tmp0 = blk[5 * 8] - blk[3 * 8];
79  tmp1 = blk[5 * 8] + blk[3 * 8];
80  tmp2 = blk[1 * 8] * 2 - (blk[7 * 8] >> 2);
81  tmp3 = blk[1 * 8] * 2 + (blk[7 * 8] >> 2);
82  tmp4 = tmp3 - tmp1;
83  tmp5 = IDCTMUL(tmp0 + tmp2, FIX_1_847);
84  tmp6 = IDCTMUL(tmp2, FIX_1_082) - tmp5;
85  tmp7 = tmp5 - IDCTMUL(tmp0, FIX_2_613) * 2;
86  tmp8 = (tmp3 + tmp1) >> 1;
87  tmp9 = tmp7 * 2 - tmp8;
88  tmpA = IDCTMUL(tmp4, FIX_1_414) * 2 - tmp9;
89  tmpB = tmp6 * 2 + tmpA;
90  tmpC = blk[2 * 8] + (blk[6 * 8] >> 1) >> 1;
91  tmpD = blk[2 * 8] - (blk[6 * 8] >> 1);
92  tmpE = (blk[0 * 8] >> 1) - (blk[4 * 8] >> 1) + 0x2020;
93  tmpF = (blk[0 * 8] >> 1) + (blk[4 * 8] >> 1) + 0x2020;
94 
95  tmp10 = IDCTMUL(tmpD, FIX_1_414) * 2 - tmpC;
96  tmp11 = tmpE - tmp10;
97  tmp12 = tmpF - tmpC;
98  tmp13 = tmpE + tmp10;
99  tmp14 = tmpF + tmpC;
100 
101  blk[0 * 8] = (tmp14 + tmp8) >> 6;
102  blk[1 * 8] = (tmp13 + tmp9) >> 6;
103  blk[2 * 8] = (tmp11 + tmpA) >> 6;
104  blk[3 * 8] = (tmp12 - tmpB) >> 6;
105  blk[4 * 8] = (tmp12 + tmpB) >> 6;
106  blk[5 * 8] = (tmp11 - tmpA) >> 6;
107  blk[6 * 8] = (tmp13 - tmp9) >> 6;
108  blk[7 * 8] = (tmp14 - tmp8) >> 6;
109 }
110 
111 static void hq_idct_put(uint8_t *dst, int stride, int16_t *block)
112 {
113  int i, j;
114 
115  for (i = 0; i < 8; i++)
116  idct_row(block + i * 8);
117  for (i = 0; i < 8; i++)
118  idct_col(block + i);
119 
120  for (i = 0; i < 8; i++) {
121  for (j = 0; j < 8; j++)
122  dst[j] = av_clip_uint8(block[j + i * 8]);
123  dst += stride;
124  }
125 }
126 
128 {
129  c->idct_put = hq_idct_put;
130 }
#define FIX_1_847
Definition: hq_hqadsp.c:29
#define FIX_2_613
Definition: hq_hqadsp.c:31
#define blk(i)
Definition: sha.c:185
Macro definitions for various function/variable attributes.
HQ/HQA variant of AAN IDCT It differs from the standard AAN IDCT in precision and in the second stage...
#define FIX_1_082
Definition: hq_hqadsp.c:28
The exact code depends on how similar the blocks are and how related they are to the block
uint8_t
#define av_cold
Definition: attributes.h:82
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
void(* idct_put)(uint8_t *dst, int stride, int16_t *block)
Definition: hq_hqadsp.h:33
#define FIX_1_414
Definition: hq_hqadsp.c:30
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
static void idct_col(int16_t *blk)
Definition: hq_hqadsp.c:73
static void hq_idct_put(uint8_t *dst, int stride, int16_t *block)
Definition: hq_hqadsp.c:111
static void idct_row(int16_t *blk)
Definition: hq_hqadsp.c:35
GLint GLenum GLboolean GLsizei stride
Definition: opengl_enc.c:104
common internal and external API header
#define IDCTMUL(a, b)
Definition: hq_hqadsp.c:33
av_cold void ff_hqdsp_init(HQDSPContext *c)
Definition: hq_hqadsp.c:127
#define stride