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