1/*
2 * Copyright (C) 2007  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
24int ff_split_xiph_headers(uint8_t *extradata, int extradata_size,
25                          int first_header_size, 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