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
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])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 AVERROR_INVALIDDATA;
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 AVERROR_INVALIDDATA;
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