FFmpeg
h263dsp.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #include <stdint.h>
20 
21 #include "libavutil/attributes.h"
22 #include "libavutil/common.h"
23 #include "config.h"
24 #include "h263dsp.h"
25 
26 const uint8_t ff_h263_loop_filter_strength[32] = {
27  0, 1, 1, 2, 2, 3, 3, 4, 4, 4, 5, 5, 6, 6, 7, 7,
28  7, 8, 8, 8, 9, 9, 9, 10, 10, 10, 11, 11, 11, 12, 12, 12
29 };
30 
31 static void h263_h_loop_filter_c(uint8_t *src, int stride, int qscale)
32 {
33  int y;
34  const int strength = ff_h263_loop_filter_strength[qscale];
35 
36  for (y = 0; y < 8; y++) {
37  int d1, d2, ad1;
38  int p0 = src[y * stride - 2];
39  int p1 = src[y * stride - 1];
40  int p2 = src[y * stride + 0];
41  int p3 = src[y * stride + 1];
42  int d = (p0 - p3 + 4 * (p2 - p1)) / 8;
43 
44  if (d < -2 * strength)
45  d1 = 0;
46  else if (d < -strength)
47  d1 = -2 * strength - d;
48  else if (d < strength)
49  d1 = d;
50  else if (d < 2 * strength)
51  d1 = 2 * strength - d;
52  else
53  d1 = 0;
54 
55  p1 += d1;
56  p2 -= d1;
57  if (p1 & 256)
58  p1 = ~(p1 >> 31);
59  if (p2 & 256)
60  p2 = ~(p2 >> 31);
61 
62  src[y * stride - 1] = p1;
63  src[y * stride + 0] = p2;
64 
65  ad1 = FFABS(d1) >> 1;
66 
67  d2 = av_clip((p0 - p3) / 4, -ad1, ad1);
68 
69  src[y * stride - 2] = p0 - d2;
70  src[y * stride + 1] = p3 + d2;
71  }
72 }
73 
74 static void h263_v_loop_filter_c(uint8_t *src, int stride, int qscale)
75 {
76  int x;
77  const int strength = ff_h263_loop_filter_strength[qscale];
78 
79  for (x = 0; x < 8; x++) {
80  int d1, d2, ad1;
81  int p0 = src[x - 2 * stride];
82  int p1 = src[x - 1 * stride];
83  int p2 = src[x + 0 * stride];
84  int p3 = src[x + 1 * stride];
85  int d = (p0 - p3 + 4 * (p2 - p1)) / 8;
86 
87  if (d < -2 * strength)
88  d1 = 0;
89  else if (d < -strength)
90  d1 = -2 * strength - d;
91  else if (d < strength)
92  d1 = d;
93  else if (d < 2 * strength)
94  d1 = 2 * strength - d;
95  else
96  d1 = 0;
97 
98  p1 += d1;
99  p2 -= d1;
100  if (p1 & 256)
101  p1 = ~(p1 >> 31);
102  if (p2 & 256)
103  p2 = ~(p2 >> 31);
104 
105  src[x - 1 * stride] = p1;
106  src[x + 0 * stride] = p2;
107 
108  ad1 = FFABS(d1) >> 1;
109 
110  d2 = av_clip((p0 - p3) / 4, -ad1, ad1);
111 
112  src[x - 2 * stride] = p0 - d2;
113  src[x + stride] = p3 + d2;
114  }
115 }
116 
118 {
119  ctx->h263_h_loop_filter = h263_h_loop_filter_c;
120  ctx->h263_v_loop_filter = h263_v_loop_filter_c;
121 
122  if (ARCH_X86)
124  if (ARCH_MIPS)
126 }
stride
int stride
Definition: mace.c:144
av_clip
#define av_clip
Definition: common.h:96
h263dsp.h
h263_v_loop_filter_c
static void h263_v_loop_filter_c(uint8_t *src, int stride, int qscale)
Definition: h263dsp.c:74
ff_h263dsp_init
av_cold void ff_h263dsp_init(H263DSPContext *ctx)
Definition: h263dsp.c:117
h263_h_loop_filter_c
static void h263_h_loop_filter_c(uint8_t *src, int stride, int qscale)
Definition: h263dsp.c:31
H263DSPContext
Definition: h263dsp.h:26
av_cold
#define av_cold
Definition: attributes.h:90
ff_h263dsp_init_x86
void ff_h263dsp_init_x86(H263DSPContext *ctx)
Definition: h263dsp_init.c:31
ctx
AVFormatContext * ctx
Definition: movenc.c:48
FFABS
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:65
src
#define src
Definition: vp8dsp.c:255
attributes.h
common.h
ff_h263_loop_filter_strength
const uint8_t ff_h263_loop_filter_strength[32]
Definition: h263dsp.c:26
d
d
Definition: ffmpeg_filter.c:156
ff_h263dsp_init_mips
void ff_h263dsp_init_mips(H263DSPContext *ctx)
Definition: h263dsp_init_mips.c:25