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
|
/*
* FLV decoding.
*
* 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 "libavutil/imgutils.h"
#include "codec_internal.h"
#include "flvdec.h"
#include "h263dec.h"
#include "mpegvideo.h"
#include "mpegvideodata.h"
int ff_flv_decode_picture_header(MpegEncContext *s)
{
int format, width, height;
/* picture header */
if (get_bits(&s->gb, 17) != 1) {
av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
return AVERROR_INVALIDDATA;
}
format = get_bits(&s->gb, 5);
if (format != 0 && format != 1) {
av_log(s->avctx, AV_LOG_ERROR, "Bad picture format\n");
return AVERROR_INVALIDDATA;
}
s->h263_flv = format + 1;
s->picture_number = get_bits(&s->gb, 8); /* picture timestamp */
format = get_bits(&s->gb, 3);
switch (format) {
case 0:
width = get_bits(&s->gb, 8);
height = get_bits(&s->gb, 8);
break;
case 1:
width = get_bits(&s->gb, 16);
height = get_bits(&s->gb, 16);
break;
case 2:
width = 352;
height = 288;
break;
case 3:
width = 176;
height = 144;
break;
case 4:
width = 128;
height = 96;
break;
case 5:
width = 320;
height = 240;
break;
case 6:
width = 160;
height = 120;
break;
default:
width = height = 0;
break;
}
if (av_image_check_size(width, height, 0, s->avctx))
return AVERROR(EINVAL);
s->width = width;
s->height = height;
s->pict_type = AV_PICTURE_TYPE_I + get_bits(&s->gb, 2);
s->droppable = s->pict_type > AV_PICTURE_TYPE_P;
if (s->droppable)
s->pict_type = AV_PICTURE_TYPE_P;
skip_bits1(&s->gb); /* deblocking flag */
s->chroma_qscale = s->qscale = get_bits(&s->gb, 5);
s->h263_plus = 0;
s->h263_long_vectors = 0;
/* PEI */
if (skip_1stop_8data_bits(&s->gb) < 0)
return AVERROR_INVALIDDATA;
s->f_code = 1;
if (s->ehc_mode)
s->avctx->sample_aspect_ratio= (AVRational){1,2};
if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
av_log(s->avctx, AV_LOG_DEBUG, "%c esc_type:%d, qp:%d num:%d\n",
s->droppable ? 'D' : av_get_picture_type_char(s->pict_type),
s->h263_flv - 1, s->qscale, s->picture_number);
}
s->y_dc_scale_table = s->c_dc_scale_table = ff_mpeg1_dc_scale_table;
return 0;
}
const AVCodec ff_flv_decoder = {
.name = "flv",
.long_name = NULL_IF_CONFIG_SMALL("FLV / Sorenson Spark / Sorenson H.263 (Flash Video)"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_FLV1,
.priv_data_size = sizeof(MpegEncContext),
.init = ff_h263_decode_init,
.close = ff_h263_decode_end,
.decode = ff_h263_decode_frame,
.capabilities = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE |
FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
.max_lowres = 3,
.pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV420P,
AV_PIX_FMT_NONE },
};
|
