FFmpeg  4.0
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
int stride
Definition: mace.c:144
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...
static int16_t block[64]
Definition: dct.c:115
#define FIX_1_082
Definition: hq_hqadsp.c:28
uint8_t
#define av_cold
Definition: attributes.h:82
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
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
common internal and external API header
static double c[64]
#define IDCTMUL(a, b)
Definition: hq_hqadsp.c:33
av_cold void ff_hqdsp_init(HQDSPContext *c)
Definition: hq_hqadsp.c:127