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2ba45a60 DM |
1 | /* |
2 | * BMP parser | |
3 | * Copyright (c) 2012 Paul B Mahol | |
4 | * | |
5 | * This file is part of FFmpeg. | |
6 | * | |
7 | * FFmpeg is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU Lesser General Public | |
9 | * License as published by the Free Software Foundation; either | |
10 | * version 2.1 of the License, or (at your option) any later version. | |
11 | * | |
12 | * FFmpeg is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * Lesser General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU Lesser General Public | |
18 | * License along with FFmpeg; if not, write to the Free Software | |
19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
20 | */ | |
21 | ||
22 | /** | |
23 | * @file | |
24 | * BMP parser | |
25 | */ | |
26 | ||
27 | #include "libavutil/bswap.h" | |
28 | #include "libavutil/common.h" | |
29 | ||
30 | #include "parser.h" | |
31 | ||
32 | typedef struct BMPParseContext { | |
33 | ParseContext pc; | |
34 | uint32_t fsize; | |
35 | uint32_t remaining_size; | |
36 | } BMPParseContext; | |
37 | ||
38 | static int bmp_parse(AVCodecParserContext *s, AVCodecContext *avctx, | |
39 | const uint8_t **poutbuf, int *poutbuf_size, | |
40 | const uint8_t *buf, int buf_size) | |
41 | { | |
42 | BMPParseContext *bpc = s->priv_data; | |
43 | uint64_t state = bpc->pc.state64; | |
44 | int next = END_NOT_FOUND; | |
45 | int i = 0; | |
46 | ||
47 | *poutbuf_size = 0; | |
48 | ||
49 | restart: | |
50 | if (bpc->pc.frame_start_found <= 2+4+4) { | |
51 | for (; i < buf_size; i++) { | |
52 | state = (state << 8) | buf[i]; | |
53 | if (bpc->pc.frame_start_found == 0) { | |
54 | if ((state >> 48) == (('B' << 8) | 'M')) { | |
55 | bpc->fsize = av_bswap32(state >> 16); | |
56 | bpc->pc.frame_start_found = 1; | |
57 | } | |
58 | } else if (bpc->pc.frame_start_found == 2+4+4) { | |
59 | // unsigned hsize = av_bswap32(state>>32); | |
60 | unsigned ihsize = av_bswap32(state); | |
61 | if (ihsize < 12 || ihsize > 200) { | |
62 | bpc->pc.frame_start_found = 0; | |
63 | continue; | |
64 | } | |
65 | bpc->pc.frame_start_found++; | |
66 | bpc->remaining_size = bpc->fsize + i - 17; | |
67 | ||
68 | if (bpc->pc.index + i > 17) { | |
69 | next = i - 17; | |
70 | } else | |
71 | goto restart; | |
72 | } else if (bpc->pc.frame_start_found) | |
73 | bpc->pc.frame_start_found++; | |
74 | } | |
75 | bpc->pc.state64 = state; | |
76 | } else { | |
77 | if (bpc->remaining_size) { | |
78 | i = FFMIN(bpc->remaining_size, buf_size); | |
79 | bpc->remaining_size -= i; | |
80 | if (bpc->remaining_size) | |
81 | goto flush; | |
82 | ||
83 | bpc->pc.frame_start_found = 0; | |
84 | goto restart; | |
85 | } | |
86 | } | |
87 | ||
88 | flush: | |
89 | if (ff_combine_frame(&bpc->pc, next, &buf, &buf_size) < 0) | |
90 | return buf_size; | |
91 | ||
92 | bpc->pc.frame_start_found = 0; | |
93 | ||
94 | *poutbuf = buf; | |
95 | *poutbuf_size = buf_size; | |
96 | return next; | |
97 | } | |
98 | ||
99 | AVCodecParser ff_bmp_parser = { | |
100 | .codec_ids = { AV_CODEC_ID_BMP }, | |
101 | .priv_data_size = sizeof(BMPParseContext), | |
102 | .parser_parse = bmp_parse, | |
103 | .parser_close = ff_parse_close, | |
104 | }; |