Imported Debian version 2.5.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / h261.c
1 /*
2 * H261 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 * h261codec.
26 */
27
28 #include "avcodec.h"
29 #include "h261.h"
30
31 #define IS_FIL(a) ((a) & MB_TYPE_H261_FIL)
32
33 uint8_t ff_h261_rl_table_store[2][2 * MAX_RUN + MAX_LEVEL + 3];
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
63 void ff_h261_loop_filter(MpegEncContext *s)
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
83 av_cold void ff_h261_common_init(void)
84 {
85 static int done = 0;
86
87 if (done)
88 return;
89
90 ff_init_rl(&ff_h261_rl_tcoeff, ff_h261_rl_table_store);
91 done = 1;
92 }