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/*
* fcs.cxx
*
* T38FAX Pseudo Modem
*
* Copyright (c) 2003-2004 Vyacheslav Frolov
*
* Open H323 Project
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.0 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and limitations
* under the License.
*
* The Original Code is Open H323 Library.
*
* The Initial Developer of the Original Code is Vyacheslav Frolov
*
* Contributor(s): Equivalence Pty ltd
*
* $Log: fcs.cxx,v $
* Revision 1.3 2004/07/06 16:07:24 vfrolov
* Included ptlib.h for precompiling
*
* Revision 1.2 2004/02/17 13:22:50 vfrolov
* Fixed MSVC compile errors
*
* Revision 1.1 2003/12/04 13:29:00 vfrolov
* Initial revision
*
*
*/
#include <ptlib.h>
#include "fcs.h"
///////////////////////////////////////////////////////////////
#define new PNEW
///////////////////////////////////////////////////////////////
void FCS::build(const void *_pBuf, PINDEX count)
{
const BYTE *pBuf = (const BYTE *)_pBuf;
for (PINDEX i = 0 ; i < count ; i++) {
BYTE c = *(pBuf++);
for (BYTE m = 0x80 ; m ; m >>= 1) {
fcs <<= 1;
if (c & m)
fcs ^= 0x10000;
if (fcs & 0x10000)
fcs ^= 0x11021;
}
}
}
///////////////////////////////////////////////////////////////
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