ffmpeg/libavformat/id3v2.c

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/*
* ID3v2 header parser
* Copyright (c) 2003 Fabrice Bellard
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "id3v2.h"
int ff_id3v2_match(const uint8_t *buf)
{
return buf[0] == 'I' &&
buf[1] == 'D' &&
buf[2] == '3' &&
buf[3] != 0xff &&
buf[4] != 0xff &&
(buf[6] & 0x80) == 0 &&
(buf[7] & 0x80) == 0 &&
(buf[8] & 0x80) == 0 &&
(buf[9] & 0x80) == 0;
}
int ff_id3v2_tag_len(const uint8_t * buf)
{
int len = ((buf[6] & 0x7f) << 21) +
((buf[7] & 0x7f) << 14) +
((buf[8] & 0x7f) << 7) +
(buf[9] & 0x7f) +
ID3v2_HEADER_SIZE;
if (buf[5] & 0x10)
len += ID3v2_HEADER_SIZE;
return len;
}