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1 /* |
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2 * Copyright (c) 2003, 2004 Nokia Corporation and/or its subsidiary(-ies). |
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3 * All rights reserved. |
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4 * This component and the accompanying materials are made available |
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5 * under the terms of "Eclipse Public License v1.0" |
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6 * which accompanies this distribution, and is available |
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7 * at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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8 * |
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9 * Initial Contributors: |
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10 * Nokia Corporation - initial contribution. |
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11 * |
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12 * Contributors: |
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13 * |
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14 * Description: Exif data parser, that can parse both Little and Big endian |
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15 * formats |
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16 * |
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17 */ |
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18 |
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19 |
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20 // INCLUDE FILES |
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21 #include "ExifEndian.h" |
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22 #include "ExifCommon.h" |
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23 |
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24 // ============================ CLASS CExifEndianBase ========================== |
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25 // ============================ MEMBER FUNCTIONS =============================== |
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26 |
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27 // ----------------------------------------------------------------------------- |
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28 // CExifEndianBase::CExifEndianBase |
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29 // C++ default constructor can NOT contain any code, that |
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30 // might leave. |
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31 // ----------------------------------------------------------------------------- |
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32 // |
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33 CExifEndianBase::CExifEndianBase() |
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34 { |
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35 } |
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36 |
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37 // ----------------------------------------------------------------------------- |
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38 // CExifEndianBase::ConstructL |
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39 // Symbian 2nd phase constructor can leave. |
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40 // ----------------------------------------------------------------------------- |
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41 // |
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42 void CExifEndianBase::ConstructL() |
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43 { |
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44 } |
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45 |
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46 // ----------------------------------------------------------------------------- |
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47 // CExifEndianBase::NewBaseL |
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48 // Two-phased constructor. Instantiates and returns relevant derived class. |
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49 // ----------------------------------------------------------------------------- |
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50 // |
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51 CExifEndianBase* CExifEndianBase::NewBaseL( |
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52 const TUint8* aExifDataPtr, |
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53 TUint aDataLength, |
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54 TBool aIsExif ) |
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55 { |
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56 // |
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57 // Parse header. |
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58 // Find SOI (FFD8 ) |
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59 // ptr = SOI pos. |
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60 // Then check the following 10 bytes: |
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61 // APP1 Marker (FFE1) + APP1 Length (no check) + Identifier ("Exif"00) + |
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62 // Pad (00) (no check) |
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63 |
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64 //TUint8* dataStartPtr = CONST_CAST( TUint8*, aExifData.Ptr() ); |
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65 if ( !aExifDataPtr ) |
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66 { |
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67 User::Leave( KErrGeneral ); |
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68 } |
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69 TUint8* ptr = CONST_CAST( TUint8*, aExifDataPtr ) - 1; |
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70 TUint8 *pE = CONST_CAST( TUint8*, aExifDataPtr ) + aDataLength; |
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71 |
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72 // Locate the SOI marker. |
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73 do |
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74 { |
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75 if ( ptr == pE ) |
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76 { |
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77 User::Leave( KErrCorrupt ); |
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78 } |
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79 } |
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80 while ( *++ptr != KMarkerStart ); |
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81 |
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82 if ( *( ptr + 1 ) != KSoiEnd ) |
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83 { |
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84 User::Leave( KErrCorrupt ); |
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85 } |
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86 // ptr is now at SOI. |
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87 |
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88 // If original is Exif, check whether it is Little- or Big-endian. |
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89 // Otherwise create Little-endian reader. |
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90 if ( aIsExif ) |
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91 { |
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92 // Locate the APP1 marker |
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93 do |
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94 { |
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95 do |
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96 { |
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97 if ( ptr == pE ) |
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98 { |
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99 User::Leave( KErrCorrupt ); |
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100 } |
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101 } |
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102 while ( *++ptr != KMarkerStart ); |
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103 } |
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104 while ( *( ptr + 1 ) != KApp1End ); |
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105 // ptr is now at APP1 |
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106 // Skip App1 length. |
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107 ptr += 4; |
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108 |
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109 // Check the APP1 and Exif header. |
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110 if ( TExifCommon::Uint32L( ptr ) != KExifIdentifierRev ) |
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111 { |
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112 User::Leave( KErrCorrupt ); |
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113 } |
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114 ptr += 4; |
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115 |
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116 // Padding 0 after 8 bytes of data. No need to check, skip. |
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117 //if ( ( *ptr ) != 0) |
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118 // { |
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119 // User::Leave( KErrCorrupt ); |
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120 // } |
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121 ptr += 2; |
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122 |
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123 // Check if little- or big- endian, and create the reader. |
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124 if ( TExifCommon::Uint16L( ptr ) == KLittleEndian ) |
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125 { |
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126 return CExifLittleEndian::NewL( aExifDataPtr, ptr, pE, aIsExif ); |
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127 } |
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128 else if ( TExifCommon::Uint16L( ptr ) == KBigEndian ) |
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129 { |
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130 return CExifBigEndian::NewL( aExifDataPtr, ptr, pE, aIsExif ); |
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131 } |
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132 else // None of the formats match!! |
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133 { |
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134 User::Leave( KErrCorrupt ); |
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135 } |
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136 } |
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137 else |
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138 { |
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139 return CExifLittleEndian::NewL( aExifDataPtr, ptr, pE, aIsExif ); |
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140 } |
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141 |
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142 return NULL; |
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143 } |
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144 |
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145 // Destructor |
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146 CExifEndianBase::~CExifEndianBase() |
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147 { |
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148 } |
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149 |
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150 // ----------------------------------------------------------------------------- |
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151 // CExifEndianBase::CopyBufferL |
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152 // Copies the data from the location, which starts and ends with the given |
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153 // Jpeg Markers. |
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154 // ----------------------------------------------------------------------------- |
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155 // |
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156 void CExifEndianBase::CopyBufferL( |
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157 TUint16 aStartMarker, |
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158 TUint16 aEndMarker, |
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159 HBufC8*& aDestBuffer, |
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160 TBool aIncludeEnd ) |
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161 { |
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162 TUint32 startOffset = 0; |
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163 if ( LocateJpegMarker( aStartMarker, startOffset ) ) |
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164 { |
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165 User::Leave( KErrCorrupt ); |
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166 } |
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167 TUint32 endOffset = 0; |
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168 if ( LocateJpegMarker( aEndMarker, endOffset ) ) |
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169 { |
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170 User::Leave( KErrCorrupt ); |
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171 } |
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172 TUint32 size = endOffset - startOffset; |
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173 if ( aIncludeEnd ) |
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174 { |
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175 size += 2; |
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176 } |
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177 aDestBuffer = HBufC8::NewL( size ); |
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178 CleanupStack::PushL( aDestBuffer ); |
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179 |
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180 iPosOffset = startOffset; |
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181 |
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182 CopyBuffer( size, 1 , aDestBuffer ); |
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183 CleanupStack::Pop(); |
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184 } |
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185 |
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186 // ----------------------------------------------------------------------------- |
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187 // CExifEndianBase::ReadUint8 |
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188 // Gets the next 8-bit unsigned integer from the data. |
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189 // ----------------------------------------------------------------------------- |
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190 // |
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191 TInt CExifEndianBase::ReadUint8( TUint8& aInt8 ) |
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192 { |
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193 if ( iPosOffset + 1 >= iExifEndOffset ) |
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194 { |
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195 return KErrCorrupt; |
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196 } |
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197 aInt8 = *( iDataStartPtr + iPosOffset ); |
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198 ++iPosOffset; |
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199 return KErrNone; |
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200 } |
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201 |
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202 // ----------------------------------------------------------------------------- |
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203 // CExifEndianBase::MoveTo |
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204 // Moves to the specified offset. |
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205 // ----------------------------------------------------------------------------- |
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206 // |
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207 TInt CExifEndianBase::MoveTo( TUint aOffset ) |
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208 { |
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209 if ( iExifStartOffset + aOffset >= iExifEndOffset ) |
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210 { |
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211 return KErrCorrupt; |
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212 } |
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213 iPosOffset = iExifStartOffset + aOffset; |
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214 return KErrNone; |
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215 } |
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216 |
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217 // ----------------------------------------------------------------------------- |
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218 // CExifEndianBase::Skip |
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219 // Moves the current position forward by the given number of bytes. |
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220 // ----------------------------------------------------------------------------- |
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221 // |
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222 TInt CExifEndianBase::Skip( TUint aNoBytes ) |
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223 { |
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224 if ( iPosOffset + aNoBytes >= iExifEndOffset ) |
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225 { |
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226 return KErrCorrupt; |
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227 } |
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228 iPosOffset += aNoBytes; |
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229 return KErrNone; |
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230 } |
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231 |
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232 // ----------------------------------------------------------------------------- |
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233 // CExifEndianBase::Locate8 |
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234 // Locates the offset of the next specified 8-bit unsigned integer |
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235 // ----------------------------------------------------------------------------- |
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236 // |
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237 TInt CExifEndianBase::Locate8( TUint8 aSearch, TUint32& aOffset ) |
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238 { |
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239 TUint8 *pBuf = iDataStartPtr + iPosOffset; |
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240 TUint8 *pB = pBuf - 1; |
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241 TUint8* pE = iDataStartPtr + iExifEndOffset; |
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242 do |
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243 { |
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244 if ( pB == pE ) |
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245 { |
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246 return KErrCorrupt; |
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247 } |
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248 } |
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249 while ( *++pB != aSearch ); |
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250 aOffset = pB - iDataStartPtr; |
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251 return KErrNone; |
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252 } |
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253 |
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254 // ----------------------------------------------------------------------------- |
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255 // CExifEndianBase::LocateJpegMarker |
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256 // Locates the offset of the specified Jpeg Marker, which resides after the |
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257 // given offset. |
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258 // ----------------------------------------------------------------------------- |
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259 // |
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260 TInt CExifEndianBase::LocateJpegMarker( |
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261 TUint16 aMarker, |
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262 TUint32& aOffset, |
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263 TUint32 aAfter, |
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264 TUint32 aBefore ) |
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265 { |
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266 if ( aAfter < iPosOffset ) |
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267 { |
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268 aAfter = iPosOffset; |
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269 } |
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270 TUint8* startPtr = iDataStartPtr + aAfter; |
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271 if ( !aBefore ) |
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272 { |
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273 aBefore = iExifEndOffset; |
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274 } |
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275 TUint8* endPtr = iDataStartPtr + aBefore; |
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276 TUint8* pB = TExifCommon::LocateJpegMarkerPtr( |
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277 aMarker, startPtr, endPtr ); |
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278 if ( !pB ) |
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279 { |
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280 return KErrCorrupt; |
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281 } |
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282 aOffset = pB - iDataStartPtr; |
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283 return KErrNone; |
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284 } |
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285 |
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286 // ----------------------------------------------------------------------------- |
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287 // CExifEndianBase::LocateJpegMarkerFromEnd |
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288 // Locates the offset of the last specified Jpeg Marker. |
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289 // ----------------------------------------------------------------------------- |
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290 // |
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291 TInt CExifEndianBase::LocateJpegMarkerFromEnd( |
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292 TUint16 aMarker, |
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293 TUint32& aOffset, |
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294 TUint32 aAfter, |
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295 TUint32 aBefore ) |
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296 { |
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297 if ( aAfter < iPosOffset) |
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298 { |
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299 aAfter = iPosOffset; |
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300 } |
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301 TUint8* startPtr = iDataStartPtr + aAfter; |
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302 if ( !aBefore ) |
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303 { |
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304 aBefore = iExifEndOffset; |
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305 } |
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306 TUint8* endPtr = iDataStartPtr + aBefore; |
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307 TUint8* pB = TExifCommon::LocateJpegMarkerPtrFromEnd( aMarker, |
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308 startPtr, endPtr ); |
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309 if ( !pB ) |
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310 { |
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311 return KErrCorrupt; |
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312 } |
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313 aOffset = pB - iDataStartPtr; |
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314 return KErrNone; |
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315 } |
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316 |
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317 |
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318 // ============================ CLASS CExifLittleEndian ======================== |
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319 // ============================ MEMBER FUNCTIONS =============================== |
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320 |
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321 // ----------------------------------------------------------------------------- |
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322 // CExifLittleEndian::NewL |
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323 // Two-phased constructor. |
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324 // ----------------------------------------------------------------------------- |
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325 // |
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326 CExifLittleEndian* CExifLittleEndian::NewL( |
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327 const TUint8* aDataStartPtr, |
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328 TUint8* aExifStartPtr, |
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329 TUint8* aExifEndPtr, |
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330 TBool aIsExif ) |
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331 { |
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332 CExifLittleEndian* self = new( ELeave ) CExifLittleEndian(); |
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333 CleanupStack::PushL( self ); |
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334 self->ConstructL( CONST_CAST( TUint8*, aDataStartPtr ), aExifStartPtr, |
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335 aExifEndPtr, aIsExif ); |
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336 CleanupStack::Pop(); |
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337 return self; |
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338 } |
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339 |
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340 // ----------------------------------------------------------------------------- |
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341 // CExifLittleEndian::CExifLittleEndian |
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342 // C++ default constructor can NOT contain any code, that |
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343 // might leave. |
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344 // ----------------------------------------------------------------------------- |
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345 // |
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346 CExifLittleEndian::CExifLittleEndian() |
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347 { |
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348 } |
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349 |
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350 // ----------------------------------------------------------------------------- |
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351 // CExifLittleEndian::ConstructL |
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352 // Symbian 2nd phase constructor can leave. |
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353 // ----------------------------------------------------------------------------- |
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354 // |
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355 void CExifLittleEndian::ConstructL( |
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356 TUint8* aDataStartPtr, |
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357 TUint8* aExifStartPtr, |
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358 TUint8* aExifEndPtr, |
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359 TBool aIsExif ) |
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360 { |
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361 if ( !aDataStartPtr || !aExifStartPtr || !aExifEndPtr ) |
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362 { |
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363 User::Leave( KErrGeneral ); |
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364 } |
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365 iDataStartPtr = aDataStartPtr; |
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366 iExifEndOffset = aExifEndPtr - iDataStartPtr; |
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367 if ( aIsExif ) |
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368 { |
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369 iExifStartOffset = aExifStartPtr - iDataStartPtr; |
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370 if ( TExifCommon::Uint16L( aExifStartPtr + 2 ) != KExifDummyRev ) |
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371 { |
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372 User::Leave( KErrCorrupt ); |
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373 } |
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374 TUint32 ifdOffset = TExifCommon::Uint32L( aExifStartPtr + 4 ); |
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375 iPosOffset = iExifStartOffset + ifdOffset; //Locate 0th IFD position |
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376 if ( iPosOffset >= iExifEndOffset ) |
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377 { |
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378 User::Leave( KErrCorrupt ); |
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379 } |
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380 } |
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381 else |
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382 { |
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383 iPosOffset = aExifStartPtr - iDataStartPtr; |
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384 } |
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385 } |
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386 |
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387 // Destructor |
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388 CExifLittleEndian::~CExifLittleEndian() |
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389 { |
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390 } |
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391 |
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392 // ----------------------------------------------------------------------------- |
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393 // CExifLittleEndian::Locate16 |
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394 // Locates the offset of the next specified 16-bit unsigned integer. |
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395 // ----------------------------------------------------------------------------- |
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396 // |
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397 TInt CExifLittleEndian::Locate16( TUint16 aSearch, TUint32& aOffset ) |
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398 { |
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399 TUint8* pB = iDataStartPtr + iPosOffset - 1; |
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400 TUint16 atHand = *pB; |
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401 TUint8* pE = iDataStartPtr + iExifEndOffset; |
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402 TInt error = KErrNone; |
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403 do |
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404 { |
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405 if ( pB >= pE ) |
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406 { |
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407 return KErrCorrupt; |
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408 } |
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409 TRAP( error, atHand =TExifCommon::Uint16L( ++pB ) ); |
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410 } |
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411 while ( ( atHand != aSearch ) && ( error == KErrNone ) ); |
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412 if ( error ) |
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413 { |
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414 return error; |
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415 } |
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416 aOffset = pB - iDataStartPtr; |
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417 return KErrNone; |
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418 } |
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419 |
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420 // ----------------------------------------------------------------------------- |
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421 // CExifLittleEndian::ReadUint16 |
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422 // Gets the next 16-bit unsigned integer from the data. |
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423 // ----------------------------------------------------------------------------- |
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424 // |
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425 TInt CExifLittleEndian::ReadUInt16( TUint16& aInt16 ) |
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426 { |
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427 if ( iPosOffset + 2 >= iExifEndOffset ) |
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428 { |
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429 return KErrCorrupt; |
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430 } |
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431 |
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432 TRAPD( error, aInt16 = TExifCommon::Uint16L( iDataStartPtr + iPosOffset ) ); |
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433 |
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434 if ( error ) |
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435 { |
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436 return error; |
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437 } |
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438 |
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439 iPosOffset += 2; |
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440 return KErrNone; |
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441 } |
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442 |
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443 // ----------------------------------------------------------------------------- |
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444 // CExifLittleEndian::ReadUint32 |
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445 // Gets the next 32-bit unsigned integer from the data. |
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446 // ----------------------------------------------------------------------------- |
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447 // |
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448 TInt CExifLittleEndian::ReadUInt32( TUint32& aInt32 ) |
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449 { |
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450 if ( iPosOffset + 4 >= iExifEndOffset ) |
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451 { |
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452 return KErrCorrupt; |
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453 } |
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454 |
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455 TRAPD( error, aInt32 = TExifCommon::Uint32L( iDataStartPtr + iPosOffset ) ); |
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456 if ( error ) |
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457 { |
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458 return error; |
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459 } |
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460 |
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461 iPosOffset += 4; |
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462 return KErrNone; |
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463 } |
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464 |
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465 // ----------------------------------------------------------------------------- |
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466 // CExifLittleEndian::CopyBuffer |
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467 // Copies the next specified amount of data to the given descriptor. |
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468 // ----------------------------------------------------------------------------- |
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469 // |
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470 TInt CExifLittleEndian::CopyBuffer( |
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471 TUint32 aCount, |
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472 TUint8 aWordSize, |
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473 HBufC8*& aBuffer ) |
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474 { |
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475 if ( !aBuffer ) |
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476 { |
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477 return KErrCorrupt; |
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478 } |
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479 TUint bufferSize = aCount * aWordSize; |
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480 if ( iPosOffset + bufferSize >= iExifEndOffset ) |
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481 { |
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482 return KErrCorrupt; |
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483 } |
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484 |
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485 aBuffer->Des().Copy( iDataStartPtr + iPosOffset, bufferSize ); |
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486 |
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487 iPosOffset += bufferSize; |
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488 |
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489 return KErrNone; |
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490 } |
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491 |
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492 // ----------------------------------------------------------------------------- |
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493 // CExifLittleEndian::CopyBuffer |
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494 // Copies the specified amount of data located in the given offset to the |
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495 // given descriptor. |
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496 // ----------------------------------------------------------------------------- |
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497 // |
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498 TInt CExifLittleEndian::CopyBuffer( |
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499 TUint32 aOffset, |
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500 TUint32 aCount, |
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501 TUint8 aWordSize, |
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502 HBufC8*& aBuffer ) |
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503 { |
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504 if ( !aBuffer ) |
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505 { |
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506 return KErrCorrupt; |
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507 } |
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508 TUint bufferSize = aCount * aWordSize; |
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509 if ( ( aOffset + iExifStartOffset + bufferSize ) >= iExifEndOffset ) |
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510 { |
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511 return KErrCorrupt; |
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512 } |
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513 |
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514 TUint8* ptr = iDataStartPtr + iExifStartOffset + aOffset; |
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515 aBuffer->Des().Copy( ptr, bufferSize ); |
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516 |
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517 return KErrNone; |
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518 } |
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519 |
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520 |
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521 // ============================ CLASS CExifBigEndian =========================== |
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522 // ============================ MEMBER FUNCTIONS =============================== |
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523 |
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524 // ----------------------------------------------------------------------------- |
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525 // CExifBigEndian::NewL |
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526 // Two-phased constructor. |
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527 // ----------------------------------------------------------------------------- |
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528 // |
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529 CExifBigEndian* CExifBigEndian::NewL( |
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530 const TUint8* aDataStartPtr, |
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531 TUint8* aExifStartPtr, |
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532 TUint8* aExifEndPtr, |
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533 TBool aIsExif ) |
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534 { |
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535 CExifBigEndian* self = new( ELeave ) CExifBigEndian(); |
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536 CleanupStack::PushL( self ); |
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537 self->ConstructL( CONST_CAST( TUint8*, aDataStartPtr ), aExifStartPtr, |
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538 aExifEndPtr, aIsExif ); |
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539 CleanupStack::Pop(); |
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540 return self; |
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541 } |
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542 |
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543 // ----------------------------------------------------------------------------- |
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544 // CExifBigEndian::CExifBigEndian |
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545 // C++ default constructor can NOT contain any code, that |
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546 // might leave. |
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547 // ----------------------------------------------------------------------------- |
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548 // |
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549 CExifBigEndian::CExifBigEndian() |
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550 { |
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551 } |
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552 |
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553 // ----------------------------------------------------------------------------- |
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554 // CExifBigEndian::ConstructL |
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555 // Symbian 2nd phase constructor can leave. |
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556 // ----------------------------------------------------------------------------- |
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557 // |
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558 void CExifBigEndian::ConstructL( |
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559 TUint8* aDataStartPtr, |
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560 TUint8* aExifStartPtr, |
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561 TUint8* aExifEndPtr, |
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562 TBool aIsExif ) |
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563 { |
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564 if ( !aDataStartPtr || !aExifStartPtr || !aExifEndPtr ) |
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565 { |
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566 User::Leave( KErrGeneral ); |
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567 } |
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568 iDataStartPtr = aDataStartPtr; |
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569 iExifEndOffset = aExifEndPtr - iDataStartPtr; |
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570 if ( aIsExif ) |
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571 { |
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572 iExifStartOffset = aExifStartPtr - iDataStartPtr; |
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573 if ( TExifCommon::Uint16L( aExifStartPtr + 2 ) != KExifDummy ) |
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574 { |
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575 User::Leave( KErrCorrupt ); |
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576 } |
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577 |
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578 TUint8* tmpPtr = aExifStartPtr + 4; |
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579 TUint32 ifdOffset = STATIC_CAST( TUint32, ( *tmpPtr << 24 ) |
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580 + ( ( *( tmpPtr + 1 ) ) << 16 ) + ( ( *( tmpPtr + 2 ) ) << 8 ) |
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581 + ( *( tmpPtr + 3 ) ) ); |
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582 iPosOffset = ( iExifStartOffset + ifdOffset ); //Locate 0th IFD pos. |
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583 if ( iPosOffset >= iExifEndOffset ) |
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584 { |
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585 User::Leave( KErrCorrupt ); |
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586 } |
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587 } |
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588 else |
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589 { |
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590 iPosOffset = aExifStartPtr - iDataStartPtr; |
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591 } |
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592 } |
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593 |
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594 // Destructor |
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595 CExifBigEndian::~CExifBigEndian() |
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596 { |
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597 } |
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598 |
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599 // ----------------------------------------------------------------------------- |
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600 // CExifBigEndian::Locate16 |
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601 // Locates the offset of the next specified 16-bit unsigned integer. |
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602 // ----------------------------------------------------------------------------- |
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603 // |
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604 TInt CExifBigEndian::Locate16( TUint16 aSearch, TUint32& aOffset ) |
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605 { |
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606 TUint8* pB = iDataStartPtr + iPosOffset; |
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607 TUint16 atHand = *pB; |
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608 TUint8* pE = iDataStartPtr + iExifEndOffset; |
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609 do |
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610 { |
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611 if ( pB >= pE ) |
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612 { |
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613 return KErrCorrupt; |
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614 } |
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615 atHand = STATIC_CAST( TUint16, ( atHand << 8 ) + *++pB ); |
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616 } |
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617 while ( atHand != aSearch ); |
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618 aOffset = ( pB - 1 ) - iDataStartPtr; |
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619 return KErrNone; |
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620 } |
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621 |
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622 // ----------------------------------------------------------------------------- |
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623 // CExifBigEndian::ReadUInt16 |
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624 // Gets the next 16-bit unsigned integer from the data. |
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625 // ----------------------------------------------------------------------------- |
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626 // |
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627 TInt CExifBigEndian::ReadUInt16( TUint16& aInt16 ) |
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628 { |
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629 if ( iPosOffset + 2 >= iExifEndOffset ) |
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630 { |
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631 return KErrCorrupt; |
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632 } |
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633 |
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634 aInt16 = STATIC_CAST( TUint16, ( *( iDataStartPtr + iPosOffset ) << 8 ) |
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635 + *( iDataStartPtr + iPosOffset + 1 ) ); |
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636 |
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637 iPosOffset += 2; |
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638 return KErrNone; |
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639 } |
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640 |
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641 // ----------------------------------------------------------------------------- |
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642 // CExifBigEndian::ReadUInt32 |
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643 // Gets the next 32-bit unsigned integer from the data. |
|
644 // ----------------------------------------------------------------------------- |
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645 // |
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646 TInt CExifBigEndian::ReadUInt32( TUint32& aInt32 ) |
|
647 { |
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648 if ( iPosOffset + 4 >= iExifEndOffset ) |
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649 { |
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650 return KErrCorrupt; |
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651 } |
|
652 |
|
653 aInt32 = STATIC_CAST( TUint32, ( *( iDataStartPtr + iPosOffset ) << 24 ) |
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654 + ( *( iDataStartPtr + iPosOffset + 1 ) << 16 ) |
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655 + ( *( iDataStartPtr + iPosOffset + 2 ) << 8 ) |
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656 + *( iDataStartPtr + iPosOffset + 3 ) ); |
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657 |
|
658 iPosOffset += 4; |
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659 return KErrNone; |
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660 } |
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661 |
|
662 // ----------------------------------------------------------------------------- |
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663 // CExifBigEndian::CopyBuffer |
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664 // Copies the next specified amount of data to the given descriptor. |
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665 // ----------------------------------------------------------------------------- |
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666 // |
|
667 TInt CExifBigEndian::CopyBuffer( |
|
668 TUint32 aCount, |
|
669 TUint8 aWordSize, |
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670 HBufC8*& aBuffer ) |
|
671 { |
|
672 if ( !aBuffer ) |
|
673 { |
|
674 return KErrCorrupt; |
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675 } |
|
676 TInt bufferSize = aCount * aWordSize; |
|
677 if ( iPosOffset + bufferSize >= iExifEndOffset ) |
|
678 { |
|
679 return KErrCorrupt; |
|
680 } |
|
681 |
|
682 TUint8* posPtr = iDataStartPtr + iPosOffset; |
|
683 if ( aWordSize == 1 ) |
|
684 { |
|
685 aBuffer->Des().Copy( posPtr, bufferSize ); |
|
686 iPosOffset += bufferSize; |
|
687 } |
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688 else if ( aWordSize == 2 ) |
|
689 { |
|
690 TUint8* destPtr = CONST_CAST( TUint8*, aBuffer->Ptr() ); |
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691 for( TUint i = 0; i < aCount; ++i) |
|
692 { |
|
693 destPtr[0] = posPtr[1]; |
|
694 destPtr[1] = *posPtr; |
|
695 posPtr += 2; |
|
696 iPosOffset += 2; |
|
697 destPtr += 2; |
|
698 } |
|
699 } |
|
700 else |
|
701 { |
|
702 TUint8* destPtr = CONST_CAST( TUint8*, aBuffer->Ptr() ); |
|
703 for( TInt i = 0; i < bufferSize / 4; ++i) |
|
704 { |
|
705 destPtr[0] = posPtr[3]; |
|
706 destPtr[1] = posPtr[2]; |
|
707 destPtr[2] = posPtr[1]; |
|
708 destPtr[3] = *posPtr; |
|
709 posPtr += 4; |
|
710 iPosOffset += 4; |
|
711 destPtr += 4; |
|
712 } |
|
713 } |
|
714 aBuffer->Des().SetLength( bufferSize ); |
|
715 return KErrNone; |
|
716 } |
|
717 |
|
718 // ----------------------------------------------------------------------------- |
|
719 // CExifBigEndian::CopyBuffer |
|
720 // Copies the specified amount of data located in the given offset to the |
|
721 // given descriptor. |
|
722 // ----------------------------------------------------------------------------- |
|
723 // |
|
724 TInt CExifBigEndian::CopyBuffer( |
|
725 TUint32 aOffset, |
|
726 TUint32 aCount, |
|
727 TUint8 aWordSize, |
|
728 HBufC8*& aBuffer ) |
|
729 { |
|
730 if ( !aBuffer ) |
|
731 { |
|
732 return KErrCorrupt; |
|
733 } |
|
734 TInt bufferSize = aCount * aWordSize; |
|
735 if ( ( aOffset + iExifStartOffset + bufferSize ) >= iExifEndOffset ) |
|
736 { |
|
737 return KErrCorrupt; |
|
738 } |
|
739 |
|
740 TUint8* ptr = iDataStartPtr + iExifStartOffset + aOffset; |
|
741 if ( aWordSize == 1 ) |
|
742 { |
|
743 aBuffer->Des().Copy( ptr, bufferSize ); |
|
744 } |
|
745 else if ( aWordSize == 2 ) |
|
746 { |
|
747 TUint8* destPtr = CONST_CAST( TUint8*, aBuffer->Ptr() ); |
|
748 for( TUint i = 0; i < aCount; ++i) |
|
749 { |
|
750 destPtr[0] = ptr[1]; |
|
751 destPtr[1] = *ptr; |
|
752 destPtr += 2; |
|
753 ptr += 2; |
|
754 } |
|
755 } |
|
756 else |
|
757 { |
|
758 TUint8* destPtr = CONST_CAST( TUint8*, aBuffer->Ptr() ); |
|
759 for( TInt i = 0; i < bufferSize / 4; ++i) |
|
760 { |
|
761 destPtr[0] = ptr[3]; |
|
762 destPtr[1] = ptr[2]; |
|
763 destPtr[2] = ptr[1]; |
|
764 destPtr[3] = *ptr; |
|
765 destPtr += 4; |
|
766 ptr += 4; |
|
767 } |
|
768 } |
|
769 aBuffer->Des().SetLength( bufferSize ); |
|
770 return KErrNone; |
|
771 } |
|
772 |
|
773 // ----------------------------------------------------------------------------- |
|
774 // CExifEndianBase::CurrentPosOffset |
|
775 // Returns the current position of decoded data |
|
776 // ----------------------------------------------------------------------------- |
|
777 // |
|
778 void CExifEndianBase::CurrentPosOffset( TUint32& aOffset ) |
|
779 { |
|
780 aOffset = iPosOffset; |
|
781 } |