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 <limits.h>
22 #include "libavutil/error.h"
23 #include "libavutil/intreadwrite.h"
24 #include "xiph.h"
25
avpriv_split_xiph_headers(const uint8_t * extradata,int extradata_size,int first_header_size,const uint8_t * header_start[3],int header_len[3])26 int avpriv_split_xiph_headers(const uint8_t *extradata, int extradata_size,
27 int first_header_size, const uint8_t *header_start[3],
28 int header_len[3])
29 {
30 int i;
31
32 if (extradata_size >= 6 && AV_RB16(extradata) == first_header_size) {
33 int overall_len = 6;
34 for (i=0; i<3; i++) {
35 header_len[i] = AV_RB16(extradata);
36 extradata += 2;
37 header_start[i] = extradata;
38 extradata += header_len[i];
39 if (overall_len > extradata_size - header_len[i])
40 return AVERROR_INVALIDDATA;
41 overall_len += header_len[i];
42 }
43 } else if (extradata_size >= 3 && extradata_size < INT_MAX - 0x1ff && extradata[0] == 2) {
44 int overall_len = 3;
45 extradata++;
46 for (i=0; i<2; i++, extradata++) {
47 header_len[i] = 0;
48 for (; overall_len < extradata_size && *extradata==0xff; extradata++) {
49 header_len[i] += 0xff;
50 overall_len += 0xff + 1;
51 }
52 header_len[i] += *extradata;
53 overall_len += *extradata;
54 if (overall_len > extradata_size)
55 return AVERROR_INVALIDDATA;
56 }
57 header_len[2] = extradata_size - overall_len;
58 header_start[0] = extradata;
59 header_start[1] = header_start[0] + header_len[0];
60 header_start[2] = header_start[1] + header_len[1];
61 } else {
62 return -1;
63 }
64 return 0;
65 }
66