www.pudn.com > XvidQP.rar > crc.h

/* 
 *  @(#) crc.h 1.5, last edit: 6/15/94 16:55:32 
 *  @(#) 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. 
 */ 
 
#ifndef CRC_H 
#define CRC_H 
#include "all.h" 
 
// 16-Bit CRC checksum class: 
class Crc16 
{ 
  static const uint16 polynomial; 
  uint16 crc; 
 
public: 
  Crc16() { crc = 0xFFFF; } 
  void  add_bits (uint32 bitstring, uint32 length); 
		 // feed a bitstring to the crc calculation (0 < length <= 32) 
  uint16	checksum() 
  // return the calculated checksum and erase it for next calls to add_bits() 
  { 
    register uint16 sum = crc; 
    crc = 0xFFFF; 
    return sum; 
  } 
}; 
 
#endif