wbmphdr.cpp
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上传日期:2007-06-06
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文件大小:5k
- /* ***** BEGIN LICENSE BLOCK *****
- * Version: RCSL 1.0/RPSL 1.0
- *
- * Portions Copyright (c) 1995-2002 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
- * Version 1.0 (the "RPSL") available at
- * http://www.helixcommunity.org/content/rpsl unless you have licensed
- * the file under the RealNetworks Community Source License Version 1.0
- * (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.
- *
- * 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 ***** */
- #include "hxtypes.h"
- #include "hxcom.h"
- #include "wbmphdr.h"
- // pndebug
- #include "hxheap.h"
- #ifdef _DEBUG
- #undef HX_THIS_FILE
- static char HX_THIS_FILE[] = __FILE__;
- #endif
- HX_RESULT ParseWBMPHeader(BYTE* pBuf,
- UINT32 ulSize,
- REF(UINT32) rulWidth,
- REF(UINT32) rulHeight,
- REF(UINT32) rulHeaderSize)
- {
- HX_RESULT retVal = HXR_FAIL;
- // Specification for WBMP header is found in Appendix A of
- // the Wireless Application Envinorment from the WAP Forum at:
- // http://www.wapforum.org/what/technical/SPEC-WAESpec-19990524.pdf
- if (pBuf && ulSize)
- {
- // Get bitmap type
- BYTE* pBufStart = pBuf;
- BYTE* pBufLimit = pBuf + ulSize;
- UINT32 ulType = 0;
- UINT32 ulNumBytes = 0;
- HX_RESULT rv = ParseMultiByteInteger(pBuf, pBufLimit - pBuf, ulType, ulNumBytes);
- if (SUCCEEDED(rv))
- {
- // Make sure we have type 0
- if (ulType == 0)
- {
- // Advance the buffer pointer
- pBuf += ulNumBytes;
- // Get the FixHeaderField
- if (pBuf < pBufLimit)
- {
- UINT32 ulFixedHeader = *pBuf++;
- // For now, we only support extension header type 00
- if (ulFixedHeader == 0)
- {
- // Get the width
- rv = ParseMultiByteInteger(pBuf, pBufLimit - pBuf, rulWidth, ulNumBytes);
- if (SUCCEEDED(rv))
- {
- // Advance the pointer
- pBuf += ulNumBytes;
- // Get the height
- rv = ParseMultiByteInteger(pBuf, pBufLimit - pBuf, rulHeight, ulNumBytes);
- if (SUCCEEDED(rv))
- {
- // Advance the pointer
- pBuf += ulNumBytes;
- // Clear the return value
- retVal = HXR_OK;
- // Compute the number of bytes used
- rulHeaderSize = pBuf - pBufStart;
- }
- }
- }
- }
- }
- }
- }
- return retVal;
- }
- HX_RESULT ParseMultiByteInteger(BYTE* pBuf, INT32 lSize,
- REF(UINT32) rulValue,
- REF(UINT32) rulNumBytes)
- {
- HX_RESULT retVal = HXR_FAIL;
- if (pBuf && lSize > 0)
- {
- // WBMP's multi-byte format reserves the most significant bit
- // as a continuation marker. If that bit = 0, then this byte
- // is the last byte. If that bit = 1, then there are additional
- // bytes. For instance, the value 0xA0 would be represented in
- // this multi-byte format as 0x81 0x20. To parse this format,
- // we have to find the last byte and then re-pack backwards from there.
- // Find the end of the multi-byte integer
- BYTE* pBufStart = pBuf;
- BYTE* pBufLimit = pBuf + lSize;
- rulValue = 0;
- while (pBuf < pBufLimit)
- {
- rulValue = (rulValue << 7) | (*pBuf & 0x7F);
- if (!(*pBuf & 0x80))
- {
- break;
- }
- pBuf++;
- }
- // Assign the rulNumBytes out parameter
- rulNumBytes = pBuf - pBufStart + 1;
- // Clear the return value
- retVal = HXR_OK;
- }
- return retVal;
- }