svn-gvsig-desktop / tags / v1_1_1_Build_1016 / libraries / libjni-ecw / include / NCSJPCPacketLengthType.h @ 33925
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1 | 3538 | nacho | /********************************************************
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2 | ** Copyright 2002 Earth Resource Mapping Ltd.
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3 | ** This document contains proprietary source code of
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4 | ** Earth Resource Mapping Ltd, and can only be used under
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5 | ** one of the three licenses as described in the
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6 | ** license.txt file supplied with this distribution.
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7 | ** See separate license.txt file for license details
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8 | ** and conditions.
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9 | **
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10 | ** This software is covered by US patent #6,442,298,
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11 | ** #6,102,897 and #6,633,688. Rights to use these patents
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12 | ** is included in the license agreements.
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13 | **
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14 | ** FILE: $Archive: /NCS/Source/include/NCSJPCPacketLengthType.h $
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15 | ** CREATED: 18/12/2002 3:27:34 PM
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16 | ** AUTHOR: Simon Cope
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17 | ** PURPOSE: CNCSJPCPacketLengthType class header
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18 | ** EDITS: [xx] ddMmmyy NAME COMMENTS
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19 | *******************************************************/
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20 | |||
21 | #ifndef NCSJPCPACKETLENGTHTYPE_H
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22 | #define NCSJPCPACKETLENGTHTYPE_H
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23 | |||
24 | #include "NCSJPCMarker.h" |
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25 | |||
26 | /**
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27 | * CNCSJPCPacketLengthType class - the JPC Packet Length Type.
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28 | *
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29 | * @author Simon Cope
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30 | * @version $Revision$ $Author$ $Date$
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31 | */
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32 | class NCSJPC_EXPORT_ALL CNCSJPCPacketLengthType { |
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33 | public:
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34 | /** Packet length - Header usually includes Data, except when using PPM or PPT markers */
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35 | UINT32 m_nHeaderLength; |
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36 | /** Packet data length - Only when using PPM or PPT markers */
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37 | UINT32 m_nDataLength; |
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38 | |||
39 | /** Default constructor, initialises members */
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40 | CNCSJPCPacketLengthType(); |
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41 | |||
42 | /**
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43 | * Parse the fields from the JPC codestream.
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44 | * @param Stream IOStream to use to parse file.
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45 | * @return bool true on success.
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46 | */
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47 | NCS_INLINE bool Parse(CNCSJPCIOStream &Stream) {
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48 | UINT32 nTmp = 0;
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49 | bool bRet = false; |
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50 | UINT8 t8; |
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51 | |||
52 | while(bRet = Stream.ReadUINT8(t8)) {
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53 | nTmp = (nTmp << 7) | (t8 & 0x7f); |
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54 | if((t8 & 0x80) == 0) { |
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55 | break;
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56 | } |
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57 | } |
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58 | m_nHeaderLength = nTmp; |
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59 | return(bRet);
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60 | }; |
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61 | /**
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62 | * Parse the fields from a chunk of memory.
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63 | * @param UINT8* Memory buffer to parse length from.
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64 | * @param &i Index into memory buffer, incremented before return
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65 | * @return bool true on success.
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66 | */
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67 | NCS_INLINE bool Parse(UINT8 *pBuf, INT32 &i) {
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68 | UINT32 nTmp = 0;
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69 | |||
70 | while(true) { |
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71 | UINT8 t8 = pBuf[i++]; |
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72 | nTmp = (nTmp << 7) | (t8 & 0x7f); |
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73 | if((t8 & 0x80) == 0) { |
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74 | break;
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75 | } |
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76 | } |
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77 | m_nHeaderLength = nTmp; |
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78 | return(true); |
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79 | }; |
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80 | /**
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81 | * UnParse the fields to the JPC codestream.
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82 | * @param Stream IOStream to use to parse file.
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83 | * @return bool true on success.
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84 | */
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85 | NCS_INLINE bool UnParse(CNCSJPCIOStream &Stream) {
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86 | UINT32 nMask = 0xffffffff;
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87 | INT8 nShift = 0;
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88 | bool bRet = true; |
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89 | |||
90 | while(nMask & m_nHeaderLength) {
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91 | nMask <<= 7;
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92 | nShift++; |
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93 | } |
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94 | if(nShift > 0) { |
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95 | nShift--; |
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96 | nMask >>= 7;
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97 | nMask = 0x7f << (nShift * 7); |
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98 | while(nShift >= 0 && bRet) { |
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99 | bRet &= Stream.WriteUINT8((UINT8)(((m_nHeaderLength & nMask) >> (nShift * 7)) | ((nShift > 0) ? 0x80 : 0x00))); |
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100 | nShift--; |
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101 | nMask >>= 7;
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102 | } |
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103 | } else {
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104 | // Zero length
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105 | bRet &= Stream.WriteUINT8((UINT8)0x00);
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106 | } |
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107 | return(bRet);
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108 | |||
109 | }; |
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110 | }; |
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111 | |||
112 | |||
113 | #endif // !NCSJPCPACKETLENGTHTYPE_H |