blob: d072224b4a55c60184e802a12842d03c73d98df6
1 | /* |
2 | * Copyright (C) 2007 The FFmpeg Project |
3 | * |
4 | * This file is part of FFmpeg. |
5 | * |
6 | * FFmpeg is free software; you can redistribute it and/or |
7 | * modify it under the terms of the GNU Lesser General Public |
8 | * License as published by the Free Software Foundation; either |
9 | * version 2.1 of the License, or (at your option) any later version. |
10 | * |
11 | * FFmpeg is distributed in the hope that it will be useful, |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
14 | * Lesser General Public License for more details. |
15 | * |
16 | * You should have received a copy of the GNU Lesser General Public |
17 | * License along with FFmpeg; if not, write to the Free Software |
18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
19 | */ |
20 | |
21 | #include "libavutil/intreadwrite.h" |
22 | #include "xiph.h" |
23 | |
24 | int avpriv_split_xiph_headers(const uint8_t *extradata, int extradata_size, |
25 | int first_header_size, const uint8_t *header_start[3], |
26 | int header_len[3]) |
27 | { |
28 | int i; |
29 | |
30 | if (extradata_size >= 6 && AV_RB16(extradata) == first_header_size) { |
31 | int overall_len = 6; |
32 | for (i=0; i<3; i++) { |
33 | header_len[i] = AV_RB16(extradata); |
34 | extradata += 2; |
35 | header_start[i] = extradata; |
36 | extradata += header_len[i]; |
37 | if (overall_len > extradata_size - header_len[i]) |
38 | return -1; |
39 | overall_len += header_len[i]; |
40 | } |
41 | } else if (extradata_size >= 3 && extradata_size < INT_MAX - 0x1ff && extradata[0] == 2) { |
42 | int overall_len = 3; |
43 | extradata++; |
44 | for (i=0; i<2; i++, extradata++) { |
45 | header_len[i] = 0; |
46 | for (; overall_len < extradata_size && *extradata==0xff; extradata++) { |
47 | header_len[i] += 0xff; |
48 | overall_len += 0xff + 1; |
49 | } |
50 | header_len[i] += *extradata; |
51 | overall_len += *extradata; |
52 | if (overall_len > extradata_size) |
53 | return -1; |
54 | } |
55 | header_len[2] = extradata_size - overall_len; |
56 | header_start[0] = extradata; |
57 | header_start[1] = header_start[0] + header_len[0]; |
58 | header_start[2] = header_start[1] + header_len[1]; |
59 | } else { |
60 | return -1; |
61 | } |
62 | return 0; |
63 | } |
64 |