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
|
/*
* BMP parser
* Copyright (c) 2012 Paul B Mahol
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* BMP parser
*/
#include "libavutil/bswap.h"
#include "libavutil/common.h"
#include "parser.h"
typedef struct BMPParseContext {
ParseContext pc;
uint32_t fsize;
uint32_t remaining_size;
} BMPParseContext;
static int bmp_parse(AVCodecParserContext *s, AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
{
BMPParseContext *bpc = s->priv_data;
uint64_t state = bpc->pc.state64;
int next = END_NOT_FOUND;
int i = 0;
*poutbuf_size = 0;
if (buf_size == 0)
return 0;
if (!bpc->pc.frame_start_found) {
for (; i < buf_size; i++) {
state = (state << 8) | buf[i];
if ((state >> 48) == (('B' << 8) | 'M')) {
bpc->fsize = av_bswap32(state >> 16);
bpc->pc.frame_start_found = 1;
if (bpc->fsize > buf_size - i + 7)
bpc->remaining_size = bpc->fsize - buf_size + i - 7;
else
next = bpc->fsize + i - 7;
break;
}
}
bpc->pc.state64 = state;
} else {
if (bpc->remaining_size) {
i = FFMIN(bpc->remaining_size, buf_size);
bpc->remaining_size -= i;
if (bpc->remaining_size)
goto flush;
next = i;
}
}
flush:
if (ff_combine_frame(&bpc->pc, next, &buf, &buf_size) < 0)
return buf_size;
bpc->pc.frame_start_found = 0;
*poutbuf = buf;
*poutbuf_size = buf_size;
return next;
}
AVCodecParser ff_bmp_parser = {
.codec_ids = { AV_CODEC_ID_BMP },
.priv_data_size = sizeof(BMPParseContext),
.parser_parse = bmp_parse,
.parser_close = ff_parse_close,
};
|
