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1 |
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2 /* pngpread.c - read a png file in push mode |
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3 * |
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4 * Last changed in libpng 1.2.32 [September 18, 2008] |
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5 * For conditions of distribution and use, see copyright notice in png.h |
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6 * Copyright (c) 1998-2008 Glenn Randers-Pehrson |
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7 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
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8 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
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9 */ |
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10 |
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11 #define PNG_INTERNAL |
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12 #include "png.h" |
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13 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED |
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14 |
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15 /* push model modes */ |
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16 #define PNG_READ_SIG_MODE 0 |
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17 #define PNG_READ_CHUNK_MODE 1 |
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18 #define PNG_READ_IDAT_MODE 2 |
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19 #define PNG_SKIP_MODE 3 |
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20 #define PNG_READ_tEXt_MODE 4 |
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21 #define PNG_READ_zTXt_MODE 5 |
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22 #define PNG_READ_DONE_MODE 6 |
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23 #define PNG_READ_iTXt_MODE 7 |
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24 #define PNG_ERROR_MODE 8 |
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25 |
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26 void PNGAPI |
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27 png_process_data(png_structp png_ptr, png_infop info_ptr, |
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28 png_bytep buffer, png_size_t buffer_size) |
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29 { |
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30 if (png_ptr == NULL || info_ptr == NULL) return; |
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31 png_push_restore_buffer(png_ptr, buffer, buffer_size); |
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32 |
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33 while (png_ptr->buffer_size) |
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34 { |
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35 png_process_some_data(png_ptr, info_ptr); |
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36 } |
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37 } |
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38 |
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39 /* What we do with the incoming data depends on what we were previously |
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40 * doing before we ran out of data... |
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41 */ |
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42 void /* PRIVATE */ |
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43 png_process_some_data(png_structp png_ptr, png_infop info_ptr) |
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44 { |
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45 if (png_ptr == NULL) return; |
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46 switch (png_ptr->process_mode) |
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47 { |
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48 case PNG_READ_SIG_MODE: |
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49 { |
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50 png_push_read_sig(png_ptr, info_ptr); |
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51 break; |
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52 } |
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53 case PNG_READ_CHUNK_MODE: |
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54 { |
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55 png_push_read_chunk(png_ptr, info_ptr); |
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56 break; |
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57 } |
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58 case PNG_READ_IDAT_MODE: |
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59 { |
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60 png_push_read_IDAT(png_ptr); |
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61 break; |
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62 } |
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63 #if defined(PNG_READ_tEXt_SUPPORTED) |
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64 case PNG_READ_tEXt_MODE: |
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65 { |
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66 png_push_read_tEXt(png_ptr, info_ptr); |
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67 break; |
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68 } |
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69 #endif |
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70 #if defined(PNG_READ_zTXt_SUPPORTED) |
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71 case PNG_READ_zTXt_MODE: |
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72 { |
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73 png_push_read_zTXt(png_ptr, info_ptr); |
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74 break; |
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75 } |
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76 #endif |
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77 #if defined(PNG_READ_iTXt_SUPPORTED) |
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78 case PNG_READ_iTXt_MODE: |
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79 { |
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80 png_push_read_iTXt(png_ptr, info_ptr); |
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81 break; |
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82 } |
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83 #endif |
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84 case PNG_SKIP_MODE: |
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85 { |
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86 png_push_crc_finish(png_ptr); |
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87 break; |
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88 } |
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89 default: |
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90 { |
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91 png_ptr->buffer_size = 0; |
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92 break; |
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93 } |
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94 } |
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95 } |
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96 |
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97 /* Read any remaining signature bytes from the stream and compare them with |
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98 * the correct PNG signature. It is possible that this routine is called |
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99 * with bytes already read from the signature, either because they have been |
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100 * checked by the calling application, or because of multiple calls to this |
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101 * routine. |
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102 */ |
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103 void /* PRIVATE */ |
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104 png_push_read_sig(png_structp png_ptr, png_infop info_ptr) |
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105 { |
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106 png_size_t num_checked = png_ptr->sig_bytes, |
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107 num_to_check = 8 - num_checked; |
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108 |
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109 if (png_ptr->buffer_size < num_to_check) |
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110 { |
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111 num_to_check = png_ptr->buffer_size; |
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112 } |
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113 |
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114 png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]), |
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115 num_to_check); |
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116 png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check); |
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117 |
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118 if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check)) |
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119 { |
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120 if (num_checked < 4 && |
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121 png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) |
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122 png_error(png_ptr, "Not a PNG file"); |
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123 else |
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124 png_error(png_ptr, "PNG file corrupted by ASCII conversion"); |
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125 } |
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126 else |
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127 { |
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128 if (png_ptr->sig_bytes >= 8) |
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129 { |
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130 png_ptr->process_mode = PNG_READ_CHUNK_MODE; |
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131 } |
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132 } |
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133 } |
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134 |
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135 void /* PRIVATE */ |
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136 png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) |
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137 { |
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138 #ifdef PNG_USE_LOCAL_ARRAYS |
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139 PNG_CONST PNG_IHDR; |
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140 PNG_CONST PNG_IDAT; |
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141 PNG_CONST PNG_IEND; |
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142 PNG_CONST PNG_PLTE; |
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143 #if defined(PNG_READ_bKGD_SUPPORTED) |
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144 PNG_CONST PNG_bKGD; |
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145 #endif |
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146 #if defined(PNG_READ_cHRM_SUPPORTED) |
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147 PNG_CONST PNG_cHRM; |
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148 #endif |
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149 #if defined(PNG_READ_gAMA_SUPPORTED) |
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150 PNG_CONST PNG_gAMA; |
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151 #endif |
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152 #if defined(PNG_READ_hIST_SUPPORTED) |
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153 PNG_CONST PNG_hIST; |
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154 #endif |
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155 #if defined(PNG_READ_iCCP_SUPPORTED) |
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156 PNG_CONST PNG_iCCP; |
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157 #endif |
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158 #if defined(PNG_READ_iTXt_SUPPORTED) |
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159 PNG_CONST PNG_iTXt; |
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160 #endif |
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161 #if defined(PNG_READ_oFFs_SUPPORTED) |
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162 PNG_CONST PNG_oFFs; |
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163 #endif |
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164 #if defined(PNG_READ_pCAL_SUPPORTED) |
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165 PNG_CONST PNG_pCAL; |
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166 #endif |
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167 #if defined(PNG_READ_pHYs_SUPPORTED) |
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168 PNG_CONST PNG_pHYs; |
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169 #endif |
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170 #if defined(PNG_READ_sBIT_SUPPORTED) |
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171 PNG_CONST PNG_sBIT; |
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172 #endif |
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173 #if defined(PNG_READ_sCAL_SUPPORTED) |
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174 PNG_CONST PNG_sCAL; |
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175 #endif |
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176 #if defined(PNG_READ_sRGB_SUPPORTED) |
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177 PNG_CONST PNG_sRGB; |
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178 #endif |
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179 #if defined(PNG_READ_sPLT_SUPPORTED) |
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180 PNG_CONST PNG_sPLT; |
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181 #endif |
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182 #if defined(PNG_READ_tEXt_SUPPORTED) |
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183 PNG_CONST PNG_tEXt; |
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184 #endif |
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185 #if defined(PNG_READ_tIME_SUPPORTED) |
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186 PNG_CONST PNG_tIME; |
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187 #endif |
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188 #if defined(PNG_READ_tRNS_SUPPORTED) |
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189 PNG_CONST PNG_tRNS; |
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190 #endif |
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191 #if defined(PNG_READ_zTXt_SUPPORTED) |
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192 PNG_CONST PNG_zTXt; |
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193 #endif |
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194 #endif /* PNG_USE_LOCAL_ARRAYS */ |
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195 /* First we make sure we have enough data for the 4 byte chunk name |
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196 * and the 4 byte chunk length before proceeding with decoding the |
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197 * chunk data. To fully decode each of these chunks, we also make |
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198 * sure we have enough data in the buffer for the 4 byte CRC at the |
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199 * end of every chunk (except IDAT, which is handled separately). |
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200 */ |
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201 if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER)) |
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202 { |
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203 png_byte chunk_length[4]; |
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204 |
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205 if (png_ptr->buffer_size < 8) |
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206 { |
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207 png_push_save_buffer(png_ptr); |
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208 return; |
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209 } |
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210 |
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211 png_push_fill_buffer(png_ptr, chunk_length, 4); |
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212 png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); |
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213 png_reset_crc(png_ptr); |
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214 png_crc_read(png_ptr, png_ptr->chunk_name, 4); |
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215 png_check_chunk_name(png_ptr, png_ptr->chunk_name); |
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216 png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; |
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217 } |
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218 |
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219 if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) |
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220 if (png_ptr->mode & PNG_AFTER_IDAT) |
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221 png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; |
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222 |
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223 if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4)) |
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224 { |
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225 if (png_ptr->push_length != 13) |
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226 png_error(png_ptr, "Invalid IHDR length"); |
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227 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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228 { |
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229 png_push_save_buffer(png_ptr); |
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230 return; |
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231 } |
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232 png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length); |
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233 } |
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234 else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4)) |
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235 { |
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236 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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237 { |
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238 png_push_save_buffer(png_ptr); |
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239 return; |
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240 } |
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241 png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length); |
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242 |
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243 png_ptr->process_mode = PNG_READ_DONE_MODE; |
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244 png_push_have_end(png_ptr, info_ptr); |
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245 } |
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246 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED |
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247 else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name)) |
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248 { |
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249 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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250 { |
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251 png_push_save_buffer(png_ptr); |
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252 return; |
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253 } |
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254 if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) |
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255 png_ptr->mode |= PNG_HAVE_IDAT; |
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256 png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); |
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257 if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) |
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258 png_ptr->mode |= PNG_HAVE_PLTE; |
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259 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) |
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260 { |
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261 if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
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262 png_error(png_ptr, "Missing IHDR before IDAT"); |
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263 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && |
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264 !(png_ptr->mode & PNG_HAVE_PLTE)) |
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265 png_error(png_ptr, "Missing PLTE before IDAT"); |
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266 } |
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267 } |
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268 #endif |
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269 else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) |
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270 { |
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271 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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272 { |
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273 png_push_save_buffer(png_ptr); |
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274 return; |
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275 } |
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276 png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length); |
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277 } |
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278 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) |
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279 { |
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280 /* If we reach an IDAT chunk, this means we have read all of the |
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281 * header chunks, and we can start reading the image (or if this |
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282 * is called after the image has been read - we have an error). |
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283 */ |
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284 if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
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285 png_error(png_ptr, "Missing IHDR before IDAT"); |
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286 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && |
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287 !(png_ptr->mode & PNG_HAVE_PLTE)) |
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288 png_error(png_ptr, "Missing PLTE before IDAT"); |
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289 |
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290 if (png_ptr->mode & PNG_HAVE_IDAT) |
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291 { |
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292 if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT)) |
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293 if (png_ptr->push_length == 0) |
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294 return; |
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295 |
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296 if (png_ptr->mode & PNG_AFTER_IDAT) |
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297 png_error(png_ptr, "Too many IDAT's found"); |
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298 } |
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299 |
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300 png_ptr->idat_size = png_ptr->push_length; |
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301 png_ptr->mode |= PNG_HAVE_IDAT; |
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302 png_ptr->process_mode = PNG_READ_IDAT_MODE; |
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303 png_push_have_info(png_ptr, info_ptr); |
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304 png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes; |
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305 png_ptr->zstream.next_out = png_ptr->row_buf; |
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306 return; |
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307 } |
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308 #if defined(PNG_READ_gAMA_SUPPORTED) |
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309 else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4)) |
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310 { |
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311 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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312 { |
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313 png_push_save_buffer(png_ptr); |
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314 return; |
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315 } |
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316 png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length); |
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317 } |
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318 #endif |
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319 #if defined(PNG_READ_sBIT_SUPPORTED) |
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320 else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) |
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321 { |
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322 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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323 { |
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324 png_push_save_buffer(png_ptr); |
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325 return; |
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326 } |
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327 png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length); |
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328 } |
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329 #endif |
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330 #if defined(PNG_READ_cHRM_SUPPORTED) |
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331 else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4)) |
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332 { |
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333 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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334 { |
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335 png_push_save_buffer(png_ptr); |
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336 return; |
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337 } |
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338 png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length); |
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339 } |
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340 #endif |
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341 #if defined(PNG_READ_sRGB_SUPPORTED) |
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342 else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) |
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343 { |
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344 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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345 { |
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346 png_push_save_buffer(png_ptr); |
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347 return; |
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348 } |
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349 png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length); |
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350 } |
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351 #endif |
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352 #if defined(PNG_READ_iCCP_SUPPORTED) |
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353 else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4)) |
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354 { |
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355 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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356 { |
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357 png_push_save_buffer(png_ptr); |
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358 return; |
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359 } |
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360 png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length); |
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361 } |
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362 #endif |
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363 #if defined(PNG_READ_sPLT_SUPPORTED) |
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364 else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4)) |
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365 { |
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366 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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367 { |
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368 png_push_save_buffer(png_ptr); |
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369 return; |
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370 } |
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371 png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length); |
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372 } |
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373 #endif |
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374 #if defined(PNG_READ_tRNS_SUPPORTED) |
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375 else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4)) |
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376 { |
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377 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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378 { |
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379 png_push_save_buffer(png_ptr); |
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380 return; |
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381 } |
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382 png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length); |
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383 } |
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384 #endif |
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385 #if defined(PNG_READ_bKGD_SUPPORTED) |
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386 else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4)) |
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387 { |
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388 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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389 { |
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390 png_push_save_buffer(png_ptr); |
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391 return; |
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392 } |
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393 png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length); |
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394 } |
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395 #endif |
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396 #if defined(PNG_READ_hIST_SUPPORTED) |
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397 else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4)) |
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398 { |
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399 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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400 { |
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401 png_push_save_buffer(png_ptr); |
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402 return; |
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403 } |
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404 png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length); |
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405 } |
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406 #endif |
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407 #if defined(PNG_READ_pHYs_SUPPORTED) |
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408 else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4)) |
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409 { |
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410 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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411 { |
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412 png_push_save_buffer(png_ptr); |
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413 return; |
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414 } |
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415 png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length); |
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416 } |
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417 #endif |
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418 #if defined(PNG_READ_oFFs_SUPPORTED) |
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419 else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4)) |
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420 { |
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421 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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422 { |
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423 png_push_save_buffer(png_ptr); |
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424 return; |
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425 } |
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426 png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length); |
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427 } |
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428 #endif |
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429 #if defined(PNG_READ_pCAL_SUPPORTED) |
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430 else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4)) |
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431 { |
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432 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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433 { |
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434 png_push_save_buffer(png_ptr); |
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435 return; |
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436 } |
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437 png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length); |
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438 } |
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439 #endif |
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440 #if defined(PNG_READ_sCAL_SUPPORTED) |
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441 else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4)) |
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442 { |
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443 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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444 { |
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445 png_push_save_buffer(png_ptr); |
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446 return; |
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447 } |
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448 png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length); |
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449 } |
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450 #endif |
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451 #if defined(PNG_READ_tIME_SUPPORTED) |
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452 else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4)) |
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453 { |
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454 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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455 { |
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456 png_push_save_buffer(png_ptr); |
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457 return; |
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458 } |
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459 png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length); |
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460 } |
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461 #endif |
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462 #if defined(PNG_READ_tEXt_SUPPORTED) |
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463 else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) |
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464 { |
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465 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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466 { |
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467 png_push_save_buffer(png_ptr); |
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468 return; |
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469 } |
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470 png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); |
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471 } |
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472 #endif |
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473 #if defined(PNG_READ_zTXt_SUPPORTED) |
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474 else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4)) |
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475 { |
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476 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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477 { |
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478 png_push_save_buffer(png_ptr); |
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479 return; |
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480 } |
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481 png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); |
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482 } |
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483 #endif |
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484 #if defined(PNG_READ_iTXt_SUPPORTED) |
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485 else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4)) |
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486 { |
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487 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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488 { |
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489 png_push_save_buffer(png_ptr); |
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490 return; |
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491 } |
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492 png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length); |
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493 } |
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494 #endif |
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495 else |
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496 { |
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497 if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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498 { |
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499 png_push_save_buffer(png_ptr); |
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500 return; |
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501 } |
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502 png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); |
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503 } |
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504 |
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505 png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; |
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506 } |
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507 |
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508 void /* PRIVATE */ |
|
509 png_push_crc_skip(png_structp png_ptr, png_uint_32 skip) |
|
510 { |
|
511 png_ptr->process_mode = PNG_SKIP_MODE; |
|
512 png_ptr->skip_length = skip; |
|
513 } |
|
514 |
|
515 void /* PRIVATE */ |
|
516 png_push_crc_finish(png_structp png_ptr) |
|
517 { |
|
518 if (png_ptr->skip_length && png_ptr->save_buffer_size) |
|
519 { |
|
520 png_size_t save_size; |
|
521 |
|
522 if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size) |
|
523 save_size = (png_size_t)png_ptr->skip_length; |
|
524 else |
|
525 save_size = png_ptr->save_buffer_size; |
|
526 |
|
527 png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); |
|
528 |
|
529 png_ptr->skip_length -= save_size; |
|
530 png_ptr->buffer_size -= save_size; |
|
531 png_ptr->save_buffer_size -= save_size; |
|
532 png_ptr->save_buffer_ptr += save_size; |
|
533 } |
|
534 if (png_ptr->skip_length && png_ptr->current_buffer_size) |
|
535 { |
|
536 png_size_t save_size; |
|
537 |
|
538 if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size) |
|
539 save_size = (png_size_t)png_ptr->skip_length; |
|
540 else |
|
541 save_size = png_ptr->current_buffer_size; |
|
542 |
|
543 png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); |
|
544 |
|
545 png_ptr->skip_length -= save_size; |
|
546 png_ptr->buffer_size -= save_size; |
|
547 png_ptr->current_buffer_size -= save_size; |
|
548 png_ptr->current_buffer_ptr += save_size; |
|
549 } |
|
550 if (!png_ptr->skip_length) |
|
551 { |
|
552 if (png_ptr->buffer_size < 4) |
|
553 { |
|
554 png_push_save_buffer(png_ptr); |
|
555 return; |
|
556 } |
|
557 |
|
558 png_crc_finish(png_ptr, 0); |
|
559 png_ptr->process_mode = PNG_READ_CHUNK_MODE; |
|
560 } |
|
561 } |
|
562 |
|
563 void PNGAPI |
|
564 png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length) |
|
565 { |
|
566 png_bytep ptr; |
|
567 |
|
568 if (png_ptr == NULL) return; |
|
569 ptr = buffer; |
|
570 if (png_ptr->save_buffer_size) |
|
571 { |
|
572 png_size_t save_size; |
|
573 |
|
574 if (length < png_ptr->save_buffer_size) |
|
575 save_size = length; |
|
576 else |
|
577 save_size = png_ptr->save_buffer_size; |
|
578 |
|
579 png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size); |
|
580 length -= save_size; |
|
581 ptr += save_size; |
|
582 png_ptr->buffer_size -= save_size; |
|
583 png_ptr->save_buffer_size -= save_size; |
|
584 png_ptr->save_buffer_ptr += save_size; |
|
585 } |
|
586 if (length && png_ptr->current_buffer_size) |
|
587 { |
|
588 png_size_t save_size; |
|
589 |
|
590 if (length < png_ptr->current_buffer_size) |
|
591 save_size = length; |
|
592 else |
|
593 save_size = png_ptr->current_buffer_size; |
|
594 |
|
595 png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size); |
|
596 png_ptr->buffer_size -= save_size; |
|
597 png_ptr->current_buffer_size -= save_size; |
|
598 png_ptr->current_buffer_ptr += save_size; |
|
599 } |
|
600 } |
|
601 |
|
602 void /* PRIVATE */ |
|
603 png_push_save_buffer(png_structp png_ptr) |
|
604 { |
|
605 if (png_ptr->save_buffer_size) |
|
606 { |
|
607 if (png_ptr->save_buffer_ptr != png_ptr->save_buffer) |
|
608 { |
|
609 png_size_t i, istop; |
|
610 png_bytep sp; |
|
611 png_bytep dp; |
|
612 |
|
613 istop = png_ptr->save_buffer_size; |
|
614 for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer; |
|
615 i < istop; i++, sp++, dp++) |
|
616 { |
|
617 *dp = *sp; |
|
618 } |
|
619 } |
|
620 } |
|
621 if (png_ptr->save_buffer_size + png_ptr->current_buffer_size > |
|
622 png_ptr->save_buffer_max) |
|
623 { |
|
624 png_size_t new_max; |
|
625 png_bytep old_buffer; |
|
626 |
|
627 if (png_ptr->save_buffer_size > PNG_SIZE_MAX - |
|
628 (png_ptr->current_buffer_size + 256)) |
|
629 { |
|
630 png_error(png_ptr, "Potential overflow of save_buffer"); |
|
631 } |
|
632 new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256; |
|
633 old_buffer = png_ptr->save_buffer; |
|
634 png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr, |
|
635 (png_uint_32)new_max); |
|
636 png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size); |
|
637 png_free(png_ptr, old_buffer); |
|
638 png_ptr->save_buffer_max = new_max; |
|
639 } |
|
640 if (png_ptr->current_buffer_size) |
|
641 { |
|
642 png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size, |
|
643 png_ptr->current_buffer_ptr, png_ptr->current_buffer_size); |
|
644 png_ptr->save_buffer_size += png_ptr->current_buffer_size; |
|
645 png_ptr->current_buffer_size = 0; |
|
646 } |
|
647 png_ptr->save_buffer_ptr = png_ptr->save_buffer; |
|
648 png_ptr->buffer_size = 0; |
|
649 } |
|
650 |
|
651 void /* PRIVATE */ |
|
652 png_push_restore_buffer(png_structp png_ptr, png_bytep buffer, |
|
653 png_size_t buffer_length) |
|
654 { |
|
655 png_ptr->current_buffer = buffer; |
|
656 png_ptr->current_buffer_size = buffer_length; |
|
657 png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size; |
|
658 png_ptr->current_buffer_ptr = png_ptr->current_buffer; |
|
659 } |
|
660 |
|
661 void /* PRIVATE */ |
|
662 png_push_read_IDAT(png_structp png_ptr) |
|
663 { |
|
664 #ifdef PNG_USE_LOCAL_ARRAYS |
|
665 PNG_CONST PNG_IDAT; |
|
666 #endif |
|
667 if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER)) |
|
668 { |
|
669 png_byte chunk_length[4]; |
|
670 |
|
671 if (png_ptr->buffer_size < 8) |
|
672 { |
|
673 png_push_save_buffer(png_ptr); |
|
674 return; |
|
675 } |
|
676 |
|
677 png_push_fill_buffer(png_ptr, chunk_length, 4); |
|
678 png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); |
|
679 png_reset_crc(png_ptr); |
|
680 png_crc_read(png_ptr, png_ptr->chunk_name, 4); |
|
681 png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; |
|
682 |
|
683 if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) |
|
684 { |
|
685 png_ptr->process_mode = PNG_READ_CHUNK_MODE; |
|
686 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) |
|
687 png_error(png_ptr, "Not enough compressed data"); |
|
688 return; |
|
689 } |
|
690 |
|
691 png_ptr->idat_size = png_ptr->push_length; |
|
692 } |
|
693 if (png_ptr->idat_size && png_ptr->save_buffer_size) |
|
694 { |
|
695 png_size_t save_size; |
|
696 |
|
697 if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size) |
|
698 { |
|
699 save_size = (png_size_t)png_ptr->idat_size; |
|
700 /* check for overflow */ |
|
701 if ((png_uint_32)save_size != png_ptr->idat_size) |
|
702 png_error(png_ptr, "save_size overflowed in pngpread"); |
|
703 } |
|
704 else |
|
705 save_size = png_ptr->save_buffer_size; |
|
706 |
|
707 png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); |
|
708 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) |
|
709 png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size); |
|
710 png_ptr->idat_size -= save_size; |
|
711 png_ptr->buffer_size -= save_size; |
|
712 png_ptr->save_buffer_size -= save_size; |
|
713 png_ptr->save_buffer_ptr += save_size; |
|
714 } |
|
715 if (png_ptr->idat_size && png_ptr->current_buffer_size) |
|
716 { |
|
717 png_size_t save_size; |
|
718 |
|
719 if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size) |
|
720 { |
|
721 save_size = (png_size_t)png_ptr->idat_size; |
|
722 /* check for overflow */ |
|
723 if ((png_uint_32)save_size != png_ptr->idat_size) |
|
724 png_error(png_ptr, "save_size overflowed in pngpread"); |
|
725 } |
|
726 else |
|
727 save_size = png_ptr->current_buffer_size; |
|
728 |
|
729 png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); |
|
730 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) |
|
731 png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size); |
|
732 |
|
733 png_ptr->idat_size -= save_size; |
|
734 png_ptr->buffer_size -= save_size; |
|
735 png_ptr->current_buffer_size -= save_size; |
|
736 png_ptr->current_buffer_ptr += save_size; |
|
737 } |
|
738 if (!png_ptr->idat_size) |
|
739 { |
|
740 if (png_ptr->buffer_size < 4) |
|
741 { |
|
742 png_push_save_buffer(png_ptr); |
|
743 return; |
|
744 } |
|
745 |
|
746 png_crc_finish(png_ptr, 0); |
|
747 png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; |
|
748 png_ptr->mode |= PNG_AFTER_IDAT; |
|
749 } |
|
750 } |
|
751 |
|
752 void /* PRIVATE */ |
|
753 png_process_IDAT_data(png_structp png_ptr, png_bytep buffer, |
|
754 png_size_t buffer_length) |
|
755 { |
|
756 int ret; |
|
757 |
|
758 if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length) |
|
759 png_error(png_ptr, "Extra compression data"); |
|
760 |
|
761 png_ptr->zstream.next_in = buffer; |
|
762 png_ptr->zstream.avail_in = (uInt)buffer_length; |
|
763 for (;;) |
|
764 { |
|
765 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); |
|
766 if (ret != Z_OK) |
|
767 { |
|
768 if (ret == Z_STREAM_END) |
|
769 { |
|
770 if (png_ptr->zstream.avail_in) |
|
771 png_error(png_ptr, "Extra compressed data"); |
|
772 if (!(png_ptr->zstream.avail_out)) |
|
773 { |
|
774 png_push_process_row(png_ptr); |
|
775 } |
|
776 |
|
777 png_ptr->mode |= PNG_AFTER_IDAT; |
|
778 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; |
|
779 break; |
|
780 } |
|
781 else if (ret == Z_BUF_ERROR) |
|
782 break; |
|
783 else |
|
784 png_error(png_ptr, "Decompression Error"); |
|
785 } |
|
786 if (!(png_ptr->zstream.avail_out)) |
|
787 { |
|
788 if (( |
|
789 #if defined(PNG_READ_INTERLACING_SUPPORTED) |
|
790 png_ptr->interlaced && png_ptr->pass > 6) || |
|
791 (!png_ptr->interlaced && |
|
792 #endif |
|
793 png_ptr->row_number == png_ptr->num_rows)) |
|
794 { |
|
795 if (png_ptr->zstream.avail_in) |
|
796 png_warning(png_ptr, "Too much data in IDAT chunks"); |
|
797 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; |
|
798 break; |
|
799 } |
|
800 png_push_process_row(png_ptr); |
|
801 png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes; |
|
802 png_ptr->zstream.next_out = png_ptr->row_buf; |
|
803 } |
|
804 else |
|
805 break; |
|
806 } |
|
807 } |
|
808 |
|
809 void /* PRIVATE */ |
|
810 png_push_process_row(png_structp png_ptr) |
|
811 { |
|
812 png_ptr->row_info.color_type = png_ptr->color_type; |
|
813 png_ptr->row_info.width = png_ptr->iwidth; |
|
814 png_ptr->row_info.channels = png_ptr->channels; |
|
815 png_ptr->row_info.bit_depth = png_ptr->bit_depth; |
|
816 png_ptr->row_info.pixel_depth = png_ptr->pixel_depth; |
|
817 |
|
818 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth, |
|
819 png_ptr->row_info.width); |
|
820 |
|
821 png_read_filter_row(png_ptr, &(png_ptr->row_info), |
|
822 png_ptr->row_buf + 1, png_ptr->prev_row + 1, |
|
823 (int)(png_ptr->row_buf[0])); |
|
824 |
|
825 png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf, |
|
826 png_ptr->rowbytes + 1); |
|
827 |
|
828 if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA)) |
|
829 png_do_read_transformations(png_ptr); |
|
830 |
|
831 #if defined(PNG_READ_INTERLACING_SUPPORTED) |
|
832 /* blow up interlaced rows to full size */ |
|
833 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) |
|
834 { |
|
835 if (png_ptr->pass < 6) |
|
836 /* old interface (pre-1.0.9): |
|
837 png_do_read_interlace(&(png_ptr->row_info), |
|
838 png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations); |
|
839 */ |
|
840 png_do_read_interlace(png_ptr); |
|
841 |
|
842 switch (png_ptr->pass) |
|
843 { |
|
844 case 0: |
|
845 { |
|
846 int i; |
|
847 for (i = 0; i < 8 && png_ptr->pass == 0; i++) |
|
848 { |
|
849 png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
|
850 png_read_push_finish_row(png_ptr); /* updates png_ptr->pass */ |
|
851 } |
|
852 if (png_ptr->pass == 2) /* pass 1 might be empty */ |
|
853 { |
|
854 for (i = 0; i < 4 && png_ptr->pass == 2; i++) |
|
855 { |
|
856 png_push_have_row(png_ptr, png_bytep_NULL); |
|
857 png_read_push_finish_row(png_ptr); |
|
858 } |
|
859 } |
|
860 if (png_ptr->pass == 4 && png_ptr->height <= 4) |
|
861 { |
|
862 for (i = 0; i < 2 && png_ptr->pass == 4; i++) |
|
863 { |
|
864 png_push_have_row(png_ptr, png_bytep_NULL); |
|
865 png_read_push_finish_row(png_ptr); |
|
866 } |
|
867 } |
|
868 if (png_ptr->pass == 6 && png_ptr->height <= 4) |
|
869 { |
|
870 png_push_have_row(png_ptr, png_bytep_NULL); |
|
871 png_read_push_finish_row(png_ptr); |
|
872 } |
|
873 break; |
|
874 } |
|
875 case 1: |
|
876 { |
|
877 int i; |
|
878 for (i = 0; i < 8 && png_ptr->pass == 1; i++) |
|
879 { |
|
880 png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
|
881 png_read_push_finish_row(png_ptr); |
|
882 } |
|
883 if (png_ptr->pass == 2) /* skip top 4 generated rows */ |
|
884 { |
|
885 for (i = 0; i < 4 && png_ptr->pass == 2; i++) |
|
886 { |
|
887 png_push_have_row(png_ptr, png_bytep_NULL); |
|
888 png_read_push_finish_row(png_ptr); |
|
889 } |
|
890 } |
|
891 break; |
|
892 } |
|
893 case 2: |
|
894 { |
|
895 int i; |
|
896 for (i = 0; i < 4 && png_ptr->pass == 2; i++) |
|
897 { |
|
898 png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
|
899 png_read_push_finish_row(png_ptr); |
|
900 } |
|
901 for (i = 0; i < 4 && png_ptr->pass == 2; i++) |
|
902 { |
|
903 png_push_have_row(png_ptr, png_bytep_NULL); |
|
904 png_read_push_finish_row(png_ptr); |
|
905 } |
|
906 if (png_ptr->pass == 4) /* pass 3 might be empty */ |
|
907 { |
|
908 for (i = 0; i < 2 && png_ptr->pass == 4; i++) |
|
909 { |
|
910 png_push_have_row(png_ptr, png_bytep_NULL); |
|
911 png_read_push_finish_row(png_ptr); |
|
912 } |
|
913 } |
|
914 break; |
|
915 } |
|
916 case 3: |
|
917 { |
|
918 int i; |
|
919 for (i = 0; i < 4 && png_ptr->pass == 3; i++) |
|
920 { |
|
921 png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
|
922 png_read_push_finish_row(png_ptr); |
|
923 } |
|
924 if (png_ptr->pass == 4) /* skip top two generated rows */ |
|
925 { |
|
926 for (i = 0; i < 2 && png_ptr->pass == 4; i++) |
|
927 { |
|
928 png_push_have_row(png_ptr, png_bytep_NULL); |
|
929 png_read_push_finish_row(png_ptr); |
|
930 } |
|
931 } |
|
932 break; |
|
933 } |
|
934 case 4: |
|
935 { |
|
936 int i; |
|
937 for (i = 0; i < 2 && png_ptr->pass == 4; i++) |
|
938 { |
|
939 png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
|
940 png_read_push_finish_row(png_ptr); |
|
941 } |
|
942 for (i = 0; i < 2 && png_ptr->pass == 4; i++) |
|
943 { |
|
944 png_push_have_row(png_ptr, png_bytep_NULL); |
|
945 png_read_push_finish_row(png_ptr); |
|
946 } |
|
947 if (png_ptr->pass == 6) /* pass 5 might be empty */ |
|
948 { |
|
949 png_push_have_row(png_ptr, png_bytep_NULL); |
|
950 png_read_push_finish_row(png_ptr); |
|
951 } |
|
952 break; |
|
953 } |
|
954 case 5: |
|
955 { |
|
956 int i; |
|
957 for (i = 0; i < 2 && png_ptr->pass == 5; i++) |
|
958 { |
|
959 png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
|
960 png_read_push_finish_row(png_ptr); |
|
961 } |
|
962 if (png_ptr->pass == 6) /* skip top generated row */ |
|
963 { |
|
964 png_push_have_row(png_ptr, png_bytep_NULL); |
|
965 png_read_push_finish_row(png_ptr); |
|
966 } |
|
967 break; |
|
968 } |
|
969 case 6: |
|
970 { |
|
971 png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
|
972 png_read_push_finish_row(png_ptr); |
|
973 if (png_ptr->pass != 6) |
|
974 break; |
|
975 png_push_have_row(png_ptr, png_bytep_NULL); |
|
976 png_read_push_finish_row(png_ptr); |
|
977 } |
|
978 } |
|
979 } |
|
980 else |
|
981 #endif |
|
982 { |
|
983 png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
|
984 png_read_push_finish_row(png_ptr); |
|
985 } |
|
986 } |
|
987 |
|
988 void /* PRIVATE */ |
|
989 png_read_push_finish_row(png_structp png_ptr) |
|
990 { |
|
991 #ifdef PNG_USE_LOCAL_ARRAYS |
|
992 /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */ |
|
993 |
|
994 /* start of interlace block */ |
|
995 PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; |
|
996 |
|
997 /* offset to next interlace block */ |
|
998 PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; |
|
999 |
|
1000 /* start of interlace block in the y direction */ |
|
1001 PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; |
|
1002 |
|
1003 /* offset to next interlace block in the y direction */ |
|
1004 PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; |
|
1005 |
|
1006 /* Height of interlace block. This is not currently used - if you need |
|
1007 * it, uncomment it here and in png.h |
|
1008 PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1}; |
|
1009 */ |
|
1010 #endif |
|
1011 |
|
1012 png_ptr->row_number++; |
|
1013 if (png_ptr->row_number < png_ptr->num_rows) |
|
1014 return; |
|
1015 |
|
1016 if (png_ptr->interlaced) |
|
1017 { |
|
1018 png_ptr->row_number = 0; |
|
1019 png_memset_check(png_ptr, png_ptr->prev_row, 0, |
|
1020 png_ptr->rowbytes + 1); |
|
1021 do |
|
1022 { |
|
1023 png_ptr->pass++; |
|
1024 if ((png_ptr->pass == 1 && png_ptr->width < 5) || |
|
1025 (png_ptr->pass == 3 && png_ptr->width < 3) || |
|
1026 (png_ptr->pass == 5 && png_ptr->width < 2)) |
|
1027 png_ptr->pass++; |
|
1028 |
|
1029 if (png_ptr->pass > 7) |
|
1030 png_ptr->pass--; |
|
1031 if (png_ptr->pass >= 7) |
|
1032 break; |
|
1033 |
|
1034 png_ptr->iwidth = (png_ptr->width + |
|
1035 png_pass_inc[png_ptr->pass] - 1 - |
|
1036 png_pass_start[png_ptr->pass]) / |
|
1037 png_pass_inc[png_ptr->pass]; |
|
1038 |
|
1039 png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, |
|
1040 png_ptr->iwidth) + 1; |
|
1041 |
|
1042 if (png_ptr->transformations & PNG_INTERLACE) |
|
1043 break; |
|
1044 |
|
1045 png_ptr->num_rows = (png_ptr->height + |
|
1046 png_pass_yinc[png_ptr->pass] - 1 - |
|
1047 png_pass_ystart[png_ptr->pass]) / |
|
1048 png_pass_yinc[png_ptr->pass]; |
|
1049 |
|
1050 } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0); |
|
1051 } |
|
1052 } |
|
1053 |
|
1054 #if defined(PNG_READ_tEXt_SUPPORTED) |
|
1055 void /* PRIVATE */ |
|
1056 png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 |
|
1057 length) |
|
1058 { |
|
1059 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND)) |
|
1060 { |
|
1061 png_error(png_ptr, "Out of place tEXt"); |
|
1062 info_ptr = info_ptr; /* to quiet some compiler warnings */ |
|
1063 } |
|
1064 |
|
1065 #ifdef PNG_MAX_MALLOC_64K |
|
1066 png_ptr->skip_length = 0; /* This may not be necessary */ |
|
1067 |
|
1068 if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */ |
|
1069 { |
|
1070 png_warning(png_ptr, "tEXt chunk too large to fit in memory"); |
|
1071 png_ptr->skip_length = length - (png_uint_32)65535L; |
|
1072 length = (png_uint_32)65535L; |
|
1073 } |
|
1074 #endif |
|
1075 |
|
1076 png_ptr->current_text = (png_charp)png_malloc(png_ptr, |
|
1077 (png_uint_32)(length + 1)); |
|
1078 png_ptr->current_text[length] = '\0'; |
|
1079 png_ptr->current_text_ptr = png_ptr->current_text; |
|
1080 png_ptr->current_text_size = (png_size_t)length; |
|
1081 png_ptr->current_text_left = (png_size_t)length; |
|
1082 png_ptr->process_mode = PNG_READ_tEXt_MODE; |
|
1083 } |
|
1084 |
|
1085 void /* PRIVATE */ |
|
1086 png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr) |
|
1087 { |
|
1088 if (png_ptr->buffer_size && png_ptr->current_text_left) |
|
1089 { |
|
1090 png_size_t text_size; |
|
1091 |
|
1092 if (png_ptr->buffer_size < png_ptr->current_text_left) |
|
1093 text_size = png_ptr->buffer_size; |
|
1094 else |
|
1095 text_size = png_ptr->current_text_left; |
|
1096 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); |
|
1097 png_ptr->current_text_left -= text_size; |
|
1098 png_ptr->current_text_ptr += text_size; |
|
1099 } |
|
1100 if (!(png_ptr->current_text_left)) |
|
1101 { |
|
1102 png_textp text_ptr; |
|
1103 png_charp text; |
|
1104 png_charp key; |
|
1105 int ret; |
|
1106 |
|
1107 if (png_ptr->buffer_size < 4) |
|
1108 { |
|
1109 png_push_save_buffer(png_ptr); |
|
1110 return; |
|
1111 } |
|
1112 |
|
1113 png_push_crc_finish(png_ptr); |
|
1114 |
|
1115 #if defined(PNG_MAX_MALLOC_64K) |
|
1116 if (png_ptr->skip_length) |
|
1117 return; |
|
1118 #endif |
|
1119 |
|
1120 key = png_ptr->current_text; |
|
1121 |
|
1122 for (text = key; *text; text++) |
|
1123 /* empty loop */ ; |
|
1124 |
|
1125 if (text < key + png_ptr->current_text_size) |
|
1126 text++; |
|
1127 |
|
1128 text_ptr = (png_textp)png_malloc(png_ptr, |
|
1129 (png_uint_32)png_sizeof(png_text)); |
|
1130 text_ptr->compression = PNG_TEXT_COMPRESSION_NONE; |
|
1131 text_ptr->key = key; |
|
1132 #ifdef PNG_iTXt_SUPPORTED |
|
1133 text_ptr->lang = NULL; |
|
1134 text_ptr->lang_key = NULL; |
|
1135 #endif |
|
1136 text_ptr->text = text; |
|
1137 |
|
1138 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); |
|
1139 |
|
1140 png_free(png_ptr, key); |
|
1141 png_free(png_ptr, text_ptr); |
|
1142 png_ptr->current_text = NULL; |
|
1143 |
|
1144 if (ret) |
|
1145 png_warning(png_ptr, "Insufficient memory to store text chunk."); |
|
1146 } |
|
1147 } |
|
1148 #endif |
|
1149 |
|
1150 #if defined(PNG_READ_zTXt_SUPPORTED) |
|
1151 void /* PRIVATE */ |
|
1152 png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 |
|
1153 length) |
|
1154 { |
|
1155 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND)) |
|
1156 { |
|
1157 png_error(png_ptr, "Out of place zTXt"); |
|
1158 info_ptr = info_ptr; /* to quiet some compiler warnings */ |
|
1159 } |
|
1160 |
|
1161 #ifdef PNG_MAX_MALLOC_64K |
|
1162 /* We can't handle zTXt chunks > 64K, since we don't have enough space |
|
1163 * to be able to store the uncompressed data. Actually, the threshold |
|
1164 * is probably around 32K, but it isn't as definite as 64K is. |
|
1165 */ |
|
1166 if (length > (png_uint_32)65535L) |
|
1167 { |
|
1168 png_warning(png_ptr, "zTXt chunk too large to fit in memory"); |
|
1169 png_push_crc_skip(png_ptr, length); |
|
1170 return; |
|
1171 } |
|
1172 #endif |
|
1173 |
|
1174 png_ptr->current_text = (png_charp)png_malloc(png_ptr, |
|
1175 (png_uint_32)(length + 1)); |
|
1176 png_ptr->current_text[length] = '\0'; |
|
1177 png_ptr->current_text_ptr = png_ptr->current_text; |
|
1178 png_ptr->current_text_size = (png_size_t)length; |
|
1179 png_ptr->current_text_left = (png_size_t)length; |
|
1180 png_ptr->process_mode = PNG_READ_zTXt_MODE; |
|
1181 } |
|
1182 |
|
1183 void /* PRIVATE */ |
|
1184 png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr) |
|
1185 { |
|
1186 if (png_ptr->buffer_size && png_ptr->current_text_left) |
|
1187 { |
|
1188 png_size_t text_size; |
|
1189 |
|
1190 if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left) |
|
1191 text_size = png_ptr->buffer_size; |
|
1192 else |
|
1193 text_size = png_ptr->current_text_left; |
|
1194 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); |
|
1195 png_ptr->current_text_left -= text_size; |
|
1196 png_ptr->current_text_ptr += text_size; |
|
1197 } |
|
1198 if (!(png_ptr->current_text_left)) |
|
1199 { |
|
1200 png_textp text_ptr; |
|
1201 png_charp text; |
|
1202 png_charp key; |
|
1203 int ret; |
|
1204 png_size_t text_size, key_size; |
|
1205 |
|
1206 if (png_ptr->buffer_size < 4) |
|
1207 { |
|
1208 png_push_save_buffer(png_ptr); |
|
1209 return; |
|
1210 } |
|
1211 |
|
1212 png_push_crc_finish(png_ptr); |
|
1213 |
|
1214 key = png_ptr->current_text; |
|
1215 |
|
1216 for (text = key; *text; text++) |
|
1217 /* empty loop */ ; |
|
1218 |
|
1219 /* zTXt can't have zero text */ |
|
1220 if (text >= key + png_ptr->current_text_size) |
|
1221 { |
|
1222 png_ptr->current_text = NULL; |
|
1223 png_free(png_ptr, key); |
|
1224 return; |
|
1225 } |
|
1226 |
|
1227 text++; |
|
1228 |
|
1229 if (*text != PNG_TEXT_COMPRESSION_zTXt) /* check compression byte */ |
|
1230 { |
|
1231 png_ptr->current_text = NULL; |
|
1232 png_free(png_ptr, key); |
|
1233 return; |
|
1234 } |
|
1235 |
|
1236 text++; |
|
1237 |
|
1238 png_ptr->zstream.next_in = (png_bytep )text; |
|
1239 png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size - |
|
1240 (text - key)); |
|
1241 png_ptr->zstream.next_out = png_ptr->zbuf; |
|
1242 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
|
1243 |
|
1244 key_size = text - key; |
|
1245 text_size = 0; |
|
1246 text = NULL; |
|
1247 ret = Z_STREAM_END; |
|
1248 |
|
1249 while (png_ptr->zstream.avail_in) |
|
1250 { |
|
1251 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); |
|
1252 if (ret != Z_OK && ret != Z_STREAM_END) |
|
1253 { |
|
1254 inflateReset(&png_ptr->zstream); |
|
1255 png_ptr->zstream.avail_in = 0; |
|
1256 png_ptr->current_text = NULL; |
|
1257 png_free(png_ptr, key); |
|
1258 png_free(png_ptr, text); |
|
1259 return; |
|
1260 } |
|
1261 if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END) |
|
1262 { |
|
1263 if (text == NULL) |
|
1264 { |
|
1265 text = (png_charp)png_malloc(png_ptr, |
|
1266 (png_uint_32)(png_ptr->zbuf_size |
|
1267 - png_ptr->zstream.avail_out + key_size + 1)); |
|
1268 png_memcpy(text + key_size, png_ptr->zbuf, |
|
1269 png_ptr->zbuf_size - png_ptr->zstream.avail_out); |
|
1270 png_memcpy(text, key, key_size); |
|
1271 text_size = key_size + png_ptr->zbuf_size - |
|
1272 png_ptr->zstream.avail_out; |
|
1273 *(text + text_size) = '\0'; |
|
1274 } |
|
1275 else |
|
1276 { |
|
1277 png_charp tmp; |
|
1278 |
|
1279 tmp = text; |
|
1280 text = (png_charp)png_malloc(png_ptr, text_size + |
|
1281 (png_uint_32)(png_ptr->zbuf_size |
|
1282 - png_ptr->zstream.avail_out + 1)); |
|
1283 png_memcpy(text, tmp, text_size); |
|
1284 png_free(png_ptr, tmp); |
|
1285 png_memcpy(text + text_size, png_ptr->zbuf, |
|
1286 png_ptr->zbuf_size - png_ptr->zstream.avail_out); |
|
1287 text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out; |
|
1288 *(text + text_size) = '\0'; |
|
1289 } |
|
1290 if (ret != Z_STREAM_END) |
|
1291 { |
|
1292 png_ptr->zstream.next_out = png_ptr->zbuf; |
|
1293 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
|
1294 } |
|
1295 } |
|
1296 else |
|
1297 { |
|
1298 break; |
|
1299 } |
|
1300 |
|
1301 if (ret == Z_STREAM_END) |
|
1302 break; |
|
1303 } |
|
1304 |
|
1305 inflateReset(&png_ptr->zstream); |
|
1306 png_ptr->zstream.avail_in = 0; |
|
1307 |
|
1308 if (ret != Z_STREAM_END) |
|
1309 { |
|
1310 png_ptr->current_text = NULL; |
|
1311 png_free(png_ptr, key); |
|
1312 png_free(png_ptr, text); |
|
1313 return; |
|
1314 } |
|
1315 |
|
1316 png_ptr->current_text = NULL; |
|
1317 png_free(png_ptr, key); |
|
1318 key = text; |
|
1319 text += key_size; |
|
1320 |
|
1321 text_ptr = (png_textp)png_malloc(png_ptr, |
|
1322 (png_uint_32)png_sizeof(png_text)); |
|
1323 text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt; |
|
1324 text_ptr->key = key; |
|
1325 #ifdef PNG_iTXt_SUPPORTED |
|
1326 text_ptr->lang = NULL; |
|
1327 text_ptr->lang_key = NULL; |
|
1328 #endif |
|
1329 text_ptr->text = text; |
|
1330 |
|
1331 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); |
|
1332 |
|
1333 png_free(png_ptr, key); |
|
1334 png_free(png_ptr, text_ptr); |
|
1335 |
|
1336 if (ret) |
|
1337 png_warning(png_ptr, "Insufficient memory to store text chunk."); |
|
1338 } |
|
1339 } |
|
1340 #endif |
|
1341 |
|
1342 #if defined(PNG_READ_iTXt_SUPPORTED) |
|
1343 void /* PRIVATE */ |
|
1344 png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 |
|
1345 length) |
|
1346 { |
|
1347 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND)) |
|
1348 { |
|
1349 png_error(png_ptr, "Out of place iTXt"); |
|
1350 info_ptr = info_ptr; /* to quiet some compiler warnings */ |
|
1351 } |
|
1352 |
|
1353 #ifdef PNG_MAX_MALLOC_64K |
|
1354 png_ptr->skip_length = 0; /* This may not be necessary */ |
|
1355 |
|
1356 if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */ |
|
1357 { |
|
1358 png_warning(png_ptr, "iTXt chunk too large to fit in memory"); |
|
1359 png_ptr->skip_length = length - (png_uint_32)65535L; |
|
1360 length = (png_uint_32)65535L; |
|
1361 } |
|
1362 #endif |
|
1363 |
|
1364 png_ptr->current_text = (png_charp)png_malloc(png_ptr, |
|
1365 (png_uint_32)(length + 1)); |
|
1366 png_ptr->current_text[length] = '\0'; |
|
1367 png_ptr->current_text_ptr = png_ptr->current_text; |
|
1368 png_ptr->current_text_size = (png_size_t)length; |
|
1369 png_ptr->current_text_left = (png_size_t)length; |
|
1370 png_ptr->process_mode = PNG_READ_iTXt_MODE; |
|
1371 } |
|
1372 |
|
1373 void /* PRIVATE */ |
|
1374 png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr) |
|
1375 { |
|
1376 |
|
1377 if (png_ptr->buffer_size && png_ptr->current_text_left) |
|
1378 { |
|
1379 png_size_t text_size; |
|
1380 |
|
1381 if (png_ptr->buffer_size < png_ptr->current_text_left) |
|
1382 text_size = png_ptr->buffer_size; |
|
1383 else |
|
1384 text_size = png_ptr->current_text_left; |
|
1385 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); |
|
1386 png_ptr->current_text_left -= text_size; |
|
1387 png_ptr->current_text_ptr += text_size; |
|
1388 } |
|
1389 if (!(png_ptr->current_text_left)) |
|
1390 { |
|
1391 png_textp text_ptr; |
|
1392 png_charp key; |
|
1393 int comp_flag; |
|
1394 png_charp lang; |
|
1395 png_charp lang_key; |
|
1396 png_charp text; |
|
1397 int ret; |
|
1398 |
|
1399 if (png_ptr->buffer_size < 4) |
|
1400 { |
|
1401 png_push_save_buffer(png_ptr); |
|
1402 return; |
|
1403 } |
|
1404 |
|
1405 png_push_crc_finish(png_ptr); |
|
1406 |
|
1407 #if defined(PNG_MAX_MALLOC_64K) |
|
1408 if (png_ptr->skip_length) |
|
1409 return; |
|
1410 #endif |
|
1411 |
|
1412 key = png_ptr->current_text; |
|
1413 |
|
1414 for (lang = key; *lang; lang++) |
|
1415 /* empty loop */ ; |
|
1416 |
|
1417 if (lang < key + png_ptr->current_text_size - 3) |
|
1418 lang++; |
|
1419 |
|
1420 comp_flag = *lang++; |
|
1421 lang++; /* skip comp_type, always zero */ |
|
1422 |
|
1423 for (lang_key = lang; *lang_key; lang_key++) |
|
1424 /* empty loop */ ; |
|
1425 lang_key++; /* skip NUL separator */ |
|
1426 |
|
1427 text=lang_key; |
|
1428 if (lang_key < key + png_ptr->current_text_size - 1) |
|
1429 { |
|
1430 for (; *text; text++) |
|
1431 /* empty loop */ ; |
|
1432 } |
|
1433 |
|
1434 if (text < key + png_ptr->current_text_size) |
|
1435 text++; |
|
1436 |
|
1437 text_ptr = (png_textp)png_malloc(png_ptr, |
|
1438 (png_uint_32)png_sizeof(png_text)); |
|
1439 text_ptr->compression = comp_flag + 2; |
|
1440 text_ptr->key = key; |
|
1441 text_ptr->lang = lang; |
|
1442 text_ptr->lang_key = lang_key; |
|
1443 text_ptr->text = text; |
|
1444 text_ptr->text_length = 0; |
|
1445 text_ptr->itxt_length = png_strlen(text); |
|
1446 |
|
1447 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); |
|
1448 |
|
1449 png_ptr->current_text = NULL; |
|
1450 |
|
1451 png_free(png_ptr, text_ptr); |
|
1452 if (ret) |
|
1453 png_warning(png_ptr, "Insufficient memory to store iTXt chunk."); |
|
1454 } |
|
1455 } |
|
1456 #endif |
|
1457 |
|
1458 /* This function is called when we haven't found a handler for this |
|
1459 * chunk. If there isn't a problem with the chunk itself (ie a bad chunk |
|
1460 * name or a critical chunk), the chunk is (currently) silently ignored. |
|
1461 */ |
|
1462 void /* PRIVATE */ |
|
1463 png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 |
|
1464 length) |
|
1465 { |
|
1466 png_uint_32 skip = 0; |
|
1467 |
|
1468 if (!(png_ptr->chunk_name[0] & 0x20)) |
|
1469 { |
|
1470 #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) |
|
1471 if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != |
|
1472 PNG_HANDLE_CHUNK_ALWAYS |
|
1473 #if defined(PNG_READ_USER_CHUNKS_SUPPORTED) |
|
1474 && png_ptr->read_user_chunk_fn == NULL |
|
1475 #endif |
|
1476 ) |
|
1477 #endif |
|
1478 png_chunk_error(png_ptr, "unknown critical chunk"); |
|
1479 |
|
1480 info_ptr = info_ptr; /* to quiet some compiler warnings */ |
|
1481 } |
|
1482 |
|
1483 #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) |
|
1484 if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS) |
|
1485 { |
|
1486 #ifdef PNG_MAX_MALLOC_64K |
|
1487 if (length > (png_uint_32)65535L) |
|
1488 { |
|
1489 png_warning(png_ptr, "unknown chunk too large to fit in memory"); |
|
1490 skip = length - (png_uint_32)65535L; |
|
1491 length = (png_uint_32)65535L; |
|
1492 } |
|
1493 #endif |
|
1494 png_memcpy((png_charp)png_ptr->unknown_chunk.name, |
|
1495 (png_charp)png_ptr->chunk_name, |
|
1496 png_sizeof(png_ptr->unknown_chunk.name)); |
|
1497 png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name) - 1] |
|
1498 = '\0'; |
|
1499 |
|
1500 png_ptr->unknown_chunk.size = (png_size_t)length; |
|
1501 if (length == 0) |
|
1502 png_ptr->unknown_chunk.data = NULL; |
|
1503 else |
|
1504 { |
|
1505 png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, |
|
1506 (png_uint_32)length); |
|
1507 png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length); |
|
1508 } |
|
1509 #if defined(PNG_READ_USER_CHUNKS_SUPPORTED) |
|
1510 if (png_ptr->read_user_chunk_fn != NULL) |
|
1511 { |
|
1512 /* callback to user unknown chunk handler */ |
|
1513 int ret; |
|
1514 ret = (*(png_ptr->read_user_chunk_fn)) |
|
1515 (png_ptr, &png_ptr->unknown_chunk); |
|
1516 if (ret < 0) |
|
1517 png_chunk_error(png_ptr, "error in user chunk"); |
|
1518 if (ret == 0) |
|
1519 { |
|
1520 if (!(png_ptr->chunk_name[0] & 0x20)) |
|
1521 if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != |
|
1522 PNG_HANDLE_CHUNK_ALWAYS) |
|
1523 png_chunk_error(png_ptr, "unknown critical chunk"); |
|
1524 png_set_unknown_chunks(png_ptr, info_ptr, |
|
1525 &png_ptr->unknown_chunk, 1); |
|
1526 } |
|
1527 } |
|
1528 else |
|
1529 #endif |
|
1530 png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1); |
|
1531 png_free(png_ptr, png_ptr->unknown_chunk.data); |
|
1532 png_ptr->unknown_chunk.data = NULL; |
|
1533 } |
|
1534 else |
|
1535 #endif |
|
1536 skip=length; |
|
1537 png_push_crc_skip(png_ptr, skip); |
|
1538 } |
|
1539 |
|
1540 void /* PRIVATE */ |
|
1541 png_push_have_info(png_structp png_ptr, png_infop info_ptr) |
|
1542 { |
|
1543 if (png_ptr->info_fn != NULL) |
|
1544 (*(png_ptr->info_fn))(png_ptr, info_ptr); |
|
1545 } |
|
1546 |
|
1547 void /* PRIVATE */ |
|
1548 png_push_have_end(png_structp png_ptr, png_infop info_ptr) |
|
1549 { |
|
1550 if (png_ptr->end_fn != NULL) |
|
1551 (*(png_ptr->end_fn))(png_ptr, info_ptr); |
|
1552 } |
|
1553 |
|
1554 void /* PRIVATE */ |
|
1555 png_push_have_row(png_structp png_ptr, png_bytep row) |
|
1556 { |
|
1557 if (png_ptr->row_fn != NULL) |
|
1558 (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number, |
|
1559 (int)png_ptr->pass); |
|
1560 } |
|
1561 |
|
1562 void PNGAPI |
|
1563 png_progressive_combine_row (png_structp png_ptr, |
|
1564 png_bytep old_row, png_bytep new_row) |
|
1565 { |
|
1566 #ifdef PNG_USE_LOCAL_ARRAYS |
|
1567 PNG_CONST int FARDATA png_pass_dsp_mask[7] = |
|
1568 {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff}; |
|
1569 #endif |
|
1570 if (png_ptr == NULL) return; |
|
1571 if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */ |
|
1572 png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]); |
|
1573 } |
|
1574 |
|
1575 void PNGAPI |
|
1576 png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr, |
|
1577 png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn, |
|
1578 png_progressive_end_ptr end_fn) |
|
1579 { |
|
1580 if (png_ptr == NULL) return; |
|
1581 png_ptr->info_fn = info_fn; |
|
1582 png_ptr->row_fn = row_fn; |
|
1583 png_ptr->end_fn = end_fn; |
|
1584 |
|
1585 png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer); |
|
1586 } |
|
1587 |
|
1588 png_voidp PNGAPI |
|
1589 png_get_progressive_ptr(png_structp png_ptr) |
|
1590 { |
|
1591 if (png_ptr == NULL) return (NULL); |
|
1592 return png_ptr->io_ptr; |
|
1593 } |
|
1594 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ |