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 
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 {
121 
122  if (ARCH_X86)
123  ff_h263dsp_init_x86(ctx);
124  if (ARCH_MIPS)
126 }
void(* h263_v_loop_filter)(uint8_t *src, int stride, int qscale)
Definition: h263dsp.h:28
av_cold void ff_h263dsp_init(H263DSPContext *ctx)
Definition: h263dsp.c:117
static void h263_v_loop_filter_c(uint8_t *src, int stride, int qscale)
Definition: h263dsp.c:74
#define src
Definition: vp8dsp.c:254
Macro definitions for various function/variable attributes.
uint8_t
#define av_cold
Definition: attributes.h:82
void ff_h263dsp_init_x86(H263DSPContext *ctx)
Definition: h263dsp_init.c:31
static void h263_h_loop_filter_c(uint8_t *src, int stride, int qscale)
Definition: h263dsp.c:31
AVFormatContext * ctx
Definition: movenc.c:48
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:72
GLint GLenum GLboolean GLsizei stride
Definition: opengl_enc.c:104
common internal and external API header
const uint8_t ff_h263_loop_filter_strength[32]
Definition: h263dsp.c:26
#define stride
void ff_h263dsp_init_mips(H263DSPContext *ctx)
void(* h263_h_loop_filter)(uint8_t *src, int stride, int qscale)
Definition: h263dsp.h:27