lzw.h
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- /* ***** BEGIN LICENSE BLOCK *****
- * Source last modified: $Id: lzw.h,v 1.1.26.1 2004/07/09 01:54:26 hubbe Exp $
- *
- * Portions Copyright (c) 1995-2004 RealNetworks, Inc. All Rights Reserved.
- *
- * The contents of this file, and the files included with this file,
- * are subject to the current version of the RealNetworks Public
- * Source License (the "RPSL") available at
- * http://www.helixcommunity.org/content/rpsl unless you have licensed
- * the file under the current version of the RealNetworks Community
- * Source License (the "RCSL") available at
- * http://www.helixcommunity.org/content/rcsl, in which case the RCSL
- * will apply. You may also obtain the license terms directly from
- * RealNetworks. You may not use this file except in compliance with
- * the RPSL or, if you have a valid RCSL with RealNetworks applicable
- * to this file, the RCSL. Please see the applicable RPSL or RCSL for
- * the rights, obligations and limitations governing use of the
- * contents of the file.
- *
- * Alternatively, the contents of this file may be used under the
- * terms of the GNU General Public License Version 2 or later (the
- * "GPL") in which case the provisions of the GPL are applicable
- * instead of those above. If you wish to allow use of your version of
- * this file only under the terms of the GPL, and not to allow others
- * to use your version of this file under the terms of either the RPSL
- * or RCSL, indicate your decision by deleting the provisions above
- * and replace them with the notice and other provisions required by
- * the GPL. If you do not delete the provisions above, a recipient may
- * use your version of this file under the terms of any one of the
- * RPSL, the RCSL or the GPL.
- *
- * This file is part of the Helix DNA Technology. RealNetworks is the
- * developer of the Original Code and owns the copyrights in the
- * portions it created.
- *
- * This file, and the files included with this file, is distributed
- * and made available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY
- * KIND, EITHER EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS
- * ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES
- * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET
- * ENJOYMENT OR NON-INFRINGEMENT.
- *
- * Technology Compatibility Kit Test Suite(s) Location:
- * http://www.helixcommunity.org/content/tck
- *
- * Contributor(s):
- *
- * ***** END LICENSE BLOCK ***** */
- #ifndef _LZW_CODEC_H
- #define _LZW_CODEC_H
- #include "hxtypes.h"
- #include "hxresult.h"
- class LZWCodec
- {
- protected:
- enum
- {
- kMaxLZWBits = 12,
- kMaxLZWVal = 4096
- };
- /* Decompression member variables */
- BOOL m_bFresh;
- BOOL m_bPostClearCode;
- INT32 m_lCodeSize;
- INT32 m_lSetCodeSize;
- INT32 m_lMaxCode;
- INT32 m_lMaxCodeSize;
- INT32 m_lFirstCode;
- INT32 m_lOldCode;
- INT32 m_lClearCode;
- INT32 m_lEndCode;
- INT32 m_lTable[2][kMaxLZWVal];
- INT32 m_lStack[kMaxLZWVal << 1];
- INT32 *m_plStackPtr;
- /* Decompression input buffer variables */
- BYTE *m_pCompressedBuffer;
- INT32 m_lCompressedBufferSize;
- INT32 m_lCompressedBytesCopied;
- BYTE *m_pCurByte;
- INT32 m_lCurBit;
- INT32 m_lBytesInBuffer;
- BOOL m_bFinished;
- BOOL m_bSuspended;
- BOOL m_bAllCompressedDataCopied;
- inline void ClearTables()
- {
- INT32 i;
- for (i = 0; i < m_lClearCode; i++)
- {
- m_lTable[0][i] = 0;
- m_lTable[1][i] = i;
- }
- for (; i < kMaxLZWVal; i++)
- {
- m_lTable[0][i] = m_lTable[1][i] = 0;
- }
- };
- inline INT32 GetCode()
- {
- /* Make copy of state variables in case we run out of data */
- BYTE *pCurByte = m_pCurByte;
- INT32 lCurBit = m_lCurBit;
- INT32 lBytesInBuffer = m_lBytesInBuffer;
- // Check to make sure we have some data
- if (lBytesInBuffer < 0)
- {
- return -1;
- }
- INT32 lCode = 0;
- for (INT32 i = 0; i < m_lCodeSize; i++)
- {
- /* Copy the current bit */
- if (*pCurByte & (1 << lCurBit))
- {
- lCode |= 1 << i;
- }
- /* Increment the bit counter */
- lCurBit++;
- /* Update the buffer variables as necessary */
- if (lCurBit == 8)
- {
- if (lBytesInBuffer == 0 && i < m_lCodeSize - 1)
- {
- return -1;
- }
- pCurByte++;
- lCurBit = 0;
- lBytesInBuffer--;
- }
- }
- /* We were successful, so update the state variables */
- m_pCurByte = pCurByte;
- m_lCurBit = lCurBit;
- m_lBytesInBuffer = lBytesInBuffer;
- return lCode;
- };
- public:
- LZWCodec();
- ~LZWCodec();
- inline BOOL Finished() { return m_bFinished; }
- inline BOOL Suspended() { return m_bSuspended; }
- HX_RESULT SetCompressedBufferSize(INT32 lSize);
- HX_RESULT InitDecompress(INT32 lMinCodeBits);
- HX_RESULT AppendCompressedBuffer(BYTE *pBuffer, INT32 lBufLen);
- HX_RESULT LZWReadByte(INT32 &rlSymbol);
- };
- #endif