gusucode.com > VC++ mp3解压源代码-源码程序 > VC++ mp3解压源代码-源码程序/code/mp3/crc.cpp
//Download by http://www.NewXing.com /* crc.cpp CRC error checking */ /* * @(#) crc.cc 1.5, last edit: 6/15/94 16:55:30 * @(#) Copyright (C) 1993, 1994 Tobias Bading (bading@cs.tu-berlin.de) * @(#) Berlin University of Technology * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include "all.h" #include "crc.h" // polynomial generator const uint16 Crc16::polynomial = 0x8005; void Crc16::add_bits (uint32 bitstring, uint32 length) { uint32 bitmask = 1 << (length - 1); do if (!(crc & 0x8000) ^ !(bitstring & bitmask)) { crc <<= 1; crc ^= polynomial; } else crc <<= 1; while (bitmask >>= 1); }