1/*
2 * ID3v2 header parser
3 * Copyright (c) 2003 Fabrice Bellard
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#include "id3v2.h"
23
24int ff_id3v2_match(const uint8_t *buf)
25{
26    return  buf[0] == 'I' &&
27            buf[1] == 'D' &&
28            buf[2] == '3' &&
29            buf[3] != 0xff &&
30            buf[4] != 0xff &&
31            (buf[6] & 0x80) == 0 &&
32            (buf[7] & 0x80) == 0 &&
33            (buf[8] & 0x80) == 0 &&
34            (buf[9] & 0x80) == 0;
35}
36
37int ff_id3v2_tag_len(const uint8_t * buf)
38{
39    int len = ((buf[6] & 0x7f) << 21) +
40        ((buf[7] & 0x7f) << 14) +
41        ((buf[8] & 0x7f) << 7) +
42        (buf[9] & 0x7f) +
43        ID3v2_HEADER_SIZE;
44    if (buf[5] & 0x10)
45        len += ID3v2_HEADER_SIZE;
46    return len;
47}
48