1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
/*
* H.263i decoder
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "mpegvideo.h"
#include "h263.h"
/* don't understand why they choose a different header ! */
int ff_intel_h263_decode_picture_header(MpegEncContext *s)
{
int format;
/* picture header */
if (get_bits_long(&s->gb, 22) != 0x20) {
av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
return -1;
}
s->picture_number = get_bits(&s->gb, 8); /* picture timestamp */
if (get_bits1(&s->gb) != 1) {
av_log(s->avctx, AV_LOG_ERROR, "Bad marker\n");
return -1; /* marker */
}
if (get_bits1(&s->gb) != 0) {
av_log(s->avctx, AV_LOG_ERROR, "Bad H263 id\n");
return -1; /* h263 id */
}
skip_bits1(&s->gb); /* split screen off */
skip_bits1(&s->gb); /* camera off */
skip_bits1(&s->gb); /* freeze picture release off */
format = get_bits(&s->gb, 3);
if (format == 0 || format == 6) {
av_log(s->avctx, AV_LOG_ERROR, "Intel H263 free format not supported\n");
return -1;
}
s->h263_plus = 0;
s->pict_type = FF_I_TYPE + get_bits1(&s->gb);
s->unrestricted_mv = get_bits1(&s->gb);
s->h263_long_vectors = s->unrestricted_mv;
if (get_bits1(&s->gb) != 0) {
av_log(s->avctx, AV_LOG_ERROR, "SAC not supported\n");
return -1; /* SAC: off */
}
s->obmc= get_bits1(&s->gb);
s->pb_frame = get_bits1(&s->gb);
if (format < 6) {
s->width = h263_format[format][0];
s->height = h263_format[format][1];
}
else {
format = get_bits(&s->gb, 3);
if(format == 0 || format == 7){
av_log(s->avctx, AV_LOG_ERROR, "Wrong Intel H263 format\n");
return -1;
}
if(get_bits(&s->gb, 2))
av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
s->loop_filter = get_bits1(&s->gb);
if(get_bits1(&s->gb))
av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
if(get_bits1(&s->gb))
s->pb_frame = 2;
if(get_bits(&s->gb, 5))
av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
if(get_bits(&s->gb, 5) != 1)
av_log(s->avctx, AV_LOG_ERROR, "Invalid marker\n");
}
if(format == 6){
int ar = get_bits(&s->gb, 4);
skip_bits(&s->gb, 9); // display width
skip_bits1(&s->gb);
skip_bits(&s->gb, 9); // display height
if(ar == 15){
skip_bits(&s->gb, 8); // aspect ratio - width
skip_bits(&s->gb, 8); // aspect ratio - height
}
}
s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */
if(s->pb_frame){
skip_bits(&s->gb, 3); //temporal reference for B-frame
skip_bits(&s->gb, 2); //dbquant
}
/* PEI */
while (get_bits1(&s->gb) != 0) {
skip_bits(&s->gb, 8);
}
s->f_code = 1;
s->y_dc_scale_table=
s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
ff_h263_show_pict_info(s);
return 0;
}
AVCodec ff_h263i_decoder = {
"h263i",
AVMEDIA_TYPE_VIDEO,
CODEC_ID_H263I,
sizeof(MpegEncContext),
ff_h263_decode_init,
NULL,
ff_h263_decode_end,
ff_h263_decode_frame,
CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("Intel H.263"),
.pix_fmts= ff_pixfmt_list_420,
};
|
