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h261.c
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1 /*
2  * H.261 common code
3  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
4  * Copyright (c) 2004 Maarten Daniels
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  * H.261 codec
26  */
27 
28 #include "avcodec.h"
29 #include "h261.h"
30 
31 #define IS_FIL(a) ((a) & MB_TYPE_H261_FIL)
32 
34 
35 static void h261_loop_filter(uint8_t *src, int stride)
36 {
37  int x, y, xy, yz;
38  int temp[64];
39 
40  for (x = 0; x < 8; x++) {
41  temp[x] = 4 * src[x];
42  temp[x + 7 * 8] = 4 * src[x + 7 * stride];
43  }
44  for (y = 1; y < 7; y++) {
45  for (x = 0; x < 8; x++) {
46  xy = y * stride + x;
47  yz = y * 8 + x;
48  temp[yz] = src[xy - stride] + 2 * src[xy] + src[xy + stride];
49  }
50  }
51 
52  for (y = 0; y < 8; y++) {
53  src[y * stride] = (temp[y * 8] + 2) >> 2;
54  src[y * stride + 7] = (temp[y * 8 + 7] + 2) >> 2;
55  for (x = 1; x < 7; x++) {
56  xy = y * stride + x;
57  yz = y * 8 + x;
58  src[xy] = (temp[yz - 1] + 2 * temp[yz] + temp[yz + 1] + 8) >> 4;
59  }
60  }
61 }
62 
64 {
65  H261Context *h = (H261Context *)s;
66  const int linesize = s->linesize;
67  const int uvlinesize = s->uvlinesize;
68  uint8_t *dest_y = s->dest[0];
69  uint8_t *dest_cb = s->dest[1];
70  uint8_t *dest_cr = s->dest[2];
71 
72  if (!(IS_FIL(h->mtype)))
73  return;
74 
75  h261_loop_filter(dest_y, linesize);
76  h261_loop_filter(dest_y + 8, linesize);
77  h261_loop_filter(dest_y + 8 * linesize, linesize);
78  h261_loop_filter(dest_y + 8 * linesize + 8, linesize);
79  h261_loop_filter(dest_cb, uvlinesize);
80  h261_loop_filter(dest_cr, uvlinesize);
81 }
82 
84 {
85  static int done = 0;
86 
87  if (done)
88  return;
89 
91  done = 1;
92 }
const char * s
Definition: avisynth_c.h:768
else temp
Definition: vf_mcdeint.c:256
H261Context.
Definition: h261.h:37
#define src
Definition: vp8dsp.c:254
uint8_t
#define av_cold
Definition: attributes.h:82
#define MAX_LEVEL
Definition: rl.h:36
av_cold void ff_h261_common_init(void)
Definition: h261.c:83
int mtype
Definition: h261.h:42
Libavcodec external API header.
ptrdiff_t linesize
line size, in bytes, may be different from width
Definition: mpegvideo.h:131
av_cold int ff_rl_init(RLTable *rl, uint8_t static_store[2][2 *MAX_RUN+MAX_LEVEL+3])
Definition: rl.c:39
H.261 codec.
ptrdiff_t uvlinesize
line size, for chroma in bytes, may be different from width
Definition: mpegvideo.h:132
RLTable ff_h261_rl_tcoeff
Definition: h261data.c:150
#define IS_FIL(a)
Definition: h261.c:31
MpegEncContext.
Definition: mpegvideo.h:78
#define MAX_RUN
Definition: rl.h:35
GLint GLenum GLboolean GLsizei stride
Definition: opengl_enc.c:105
uint8_t * dest[3]
Definition: mpegvideo.h:292
static void h261_loop_filter(uint8_t *src, int stride)
Definition: h261.c:35
uint8_t ff_h261_rl_table_store[2][2 *MAX_RUN+MAX_LEVEL+3]
Definition: h261.c:33
void ff_h261_loop_filter(MpegEncContext *s)
Definition: h261.c:63
#define stride