www/plugins-dist/medias/lib/getid3/module.graphic.png.php

   1 <?php
   2 /////////////////////////////////////////////////////////////////
   3 /// getID3() by James Heinrich <info@getid3.org>               //
   4 //  available at http://getid3.sourceforge.net                 //
   5 //            or http://www.getid3.org                         //
   6 //          also https://github.com/JamesHeinrich/getID3       //
   7 /////////////////////////////////////////////////////////////////
   8 // See readme.txt for more details                             //
   9 /////////////////////////////////////////////////////////////////
  10 //                                                             //
  11 // module.graphic.png.php                                      //
  12 // module for analyzing PNG Image files                        //
  13 // dependencies: NONE                                          //
  14 //                                                            ///
  15 /////////////////////////////////////////////////////////////////
  16
  17
  18 class getid3_png extends getid3_handler
  19 {
  20         public $max_data_bytes = 10000000; // if data chunk is larger than this do not read it completely (getID3 only needs the first few dozen bytes for parsing)
  21
  22         public function Analyze() {
  23
  24                 $info = &$this->getid3->info;
  25
  26                 // shortcut
  27                 $info['png'] = array();
  28                 $thisfile_png = &$info['png'];
  29
  30                 $info['fileformat']          = 'png';
  31                 $info['video']['dataformat'] = 'png';
  32                 $info['video']['lossless']   = false;
  33
  34                 $this->fseek($info['avdataoffset']);
  35                 $PNGfiledata = $this->fread($this->getid3->fread_buffer_size());
  36                 $offset = 0;
  37
  38                 $PNGidentifier = substr($PNGfiledata, $offset, 8); // $89 $50 $4E $47 $0D $0A $1A $0A
  39                 $offset += 8;
  40
  41                 if ($PNGidentifier != "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A") {
  42                         $this->error('First 8 bytes of file ('.getid3_lib::PrintHexBytes($PNGidentifier).') did not match expected PNG identifier');
  43                         unset($info['fileformat']);
  44                         return false;
  45                 }
  46
  47                 while ((($this->ftell() - (strlen($PNGfiledata) - $offset)) < $info['filesize'])) {
  48                         $chunk['data_length'] = getid3_lib::BigEndian2Int(substr($PNGfiledata, $offset, 4));
  49                         if ($chunk['data_length'] === false) {
  50                                 $this->error('Failed to read data_length at offset '.$offset);
  51                                 return false;
  52                         }
  53                         $offset += 4;
  54                         $truncated_data = false;
  55                         while (((strlen($PNGfiledata) - $offset) < ($chunk['data_length'] + 4)) && ($this->ftell() < $info['filesize'])) {
  56                                 if (strlen($PNGfiledata) < $this->max_data_bytes) {
  57                                         $PNGfiledata .= $this->fread($this->getid3->fread_buffer_size());
  58                                 } else {
  59                                         $this->warning('At offset '.$offset.' chunk "'.substr($PNGfiledata, $offset, 4).'" exceeded max_data_bytes value of '.$this->max_data_bytes.', data chunk will be truncated at '.(strlen($PNGfiledata) - 8).' bytes');
  60                                         break;
  61                                 }
  62                         }
  63                         $chunk['type_text']   =                           substr($PNGfiledata, $offset, 4);
  64                         $offset += 4;
  65                         $chunk['type_raw']    = getid3_lib::BigEndian2Int($chunk['type_text']);
  66                         $chunk['data']        =                           substr($PNGfiledata, $offset, $chunk['data_length']);
  67                         $offset += $chunk['data_length'];
  68                         $chunk['crc']         = getid3_lib::BigEndian2Int(substr($PNGfiledata, $offset, 4));
  69                         $offset += 4;
  70
  71                         $chunk['flags']['ancilliary']   = (bool) ($chunk['type_raw'] & 0x20000000);
  72                         $chunk['flags']['private']      = (bool) ($chunk['type_raw'] & 0x00200000);
  73                         $chunk['flags']['reserved']     = (bool) ($chunk['type_raw'] & 0x00002000);
  74                         $chunk['flags']['safe_to_copy'] = (bool) ($chunk['type_raw'] & 0x00000020);
  75
  76                         // shortcut
  77                         $thisfile_png[$chunk['type_text']] = array();
  78                         $thisfile_png_chunk_type_text = &$thisfile_png[$chunk['type_text']];
  79
  80                         switch ($chunk['type_text']) {
  81
  82                                 case 'IHDR': // Image Header
  83                                         $thisfile_png_chunk_type_text['header'] = $chunk;
  84                                         $thisfile_png_chunk_type_text['width']                     = getid3_lib::BigEndian2Int(substr($chunk['data'],  0, 4));
  85                                         $thisfile_png_chunk_type_text['height']                    = getid3_lib::BigEndian2Int(substr($chunk['data'],  4, 4));
  86                                         $thisfile_png_chunk_type_text['raw']['bit_depth']          = getid3_lib::BigEndian2Int(substr($chunk['data'],  8, 1));
  87                                         $thisfile_png_chunk_type_text['raw']['color_type']         = getid3_lib::BigEndian2Int(substr($chunk['data'],  9, 1));
  88                                         $thisfile_png_chunk_type_text['raw']['compression_method'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 10, 1));
  89                                         $thisfile_png_chunk_type_text['raw']['filter_method']      = getid3_lib::BigEndian2Int(substr($chunk['data'], 11, 1));
  90                                         $thisfile_png_chunk_type_text['raw']['interlace_method']   = getid3_lib::BigEndian2Int(substr($chunk['data'], 12, 1));
  91
  92                                         $thisfile_png_chunk_type_text['compression_method_text']   = $this->PNGcompressionMethodLookup($thisfile_png_chunk_type_text['raw']['compression_method']);
  93                                         $thisfile_png_chunk_type_text['color_type']['palette']     = (bool) ($thisfile_png_chunk_type_text['raw']['color_type'] & 0x01);
  94                                         $thisfile_png_chunk_type_text['color_type']['true_color']  = (bool) ($thisfile_png_chunk_type_text['raw']['color_type'] & 0x02);
  95                                         $thisfile_png_chunk_type_text['color_type']['alpha']       = (bool) ($thisfile_png_chunk_type_text['raw']['color_type'] & 0x04);
  96
  97                                         $info['video']['resolution_x']    = $thisfile_png_chunk_type_text['width'];
  98                                         $info['video']['resolution_y']    = $thisfile_png_chunk_type_text['height'];
  99
 100                                         $info['video']['bits_per_sample'] = $this->IHDRcalculateBitsPerSample($thisfile_png_chunk_type_text['raw']['color_type'], $thisfile_png_chunk_type_text['raw']['bit_depth']);
 101                                         break;
 102
 103
 104                                 case 'PLTE': // Palette
 105                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 106                                         $paletteoffset = 0;
 107                                         for ($i = 0; $i <= 255; $i++) {
 108                                                 //$thisfile_png_chunk_type_text['red'][$i]   = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1));
 109                                                 //$thisfile_png_chunk_type_text['green'][$i] = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1));
 110                                                 //$thisfile_png_chunk_type_text['blue'][$i]  = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1));
 111                                                 $red   = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1));
 112                                                 $green = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1));
 113                                                 $blue  = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1));
 114                                                 $thisfile_png_chunk_type_text[$i] = (($red << 16) | ($green << 8) | ($blue));
 115                                         }
 116                                         break;
 117
 118
 119                                 case 'tRNS': // Transparency
 120                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 121                                         switch ($thisfile_png['IHDR']['raw']['color_type']) {
 122                                                 case 0:
 123                                                         $thisfile_png_chunk_type_text['transparent_color_gray']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 2));
 124                                                         break;
 125
 126                                                 case 2:
 127                                                         $thisfile_png_chunk_type_text['transparent_color_red']   = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 2));
 128                                                         $thisfile_png_chunk_type_text['transparent_color_green'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 2));
 129                                                         $thisfile_png_chunk_type_text['transparent_color_blue']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 2));
 130                                                         break;
 131
 132                                                 case 3:
 133                                                         for ($i = 0; $i < strlen($chunk['data']); $i++) {
 134                                                                 $thisfile_png_chunk_type_text['palette_opacity'][$i] = getid3_lib::BigEndian2Int(substr($chunk['data'], $i, 1));
 135                                                         }
 136                                                         break;
 137
 138                                                 case 4:
 139                                                 case 6:
 140                                                         $this->error('Invalid color_type in tRNS chunk: '.$thisfile_png['IHDR']['raw']['color_type']);
 141
 142                                                 default:
 143                                                         $this->warning('Unhandled color_type in tRNS chunk: '.$thisfile_png['IHDR']['raw']['color_type']);
 144                                                         break;
 145                                         }
 146                                         break;
 147
 148
 149                                 case 'gAMA': // Image Gamma
 150                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 151                                         $thisfile_png_chunk_type_text['gamma']  = getid3_lib::BigEndian2Int($chunk['data']) / 100000;
 152                                         break;
 153
 154
 155                                 case 'cHRM': // Primary Chromaticities
 156                                         $thisfile_png_chunk_type_text['header']  = $chunk;
 157                                         $thisfile_png_chunk_type_text['white_x'] = getid3_lib::BigEndian2Int(substr($chunk['data'],  0, 4)) / 100000;
 158                                         $thisfile_png_chunk_type_text['white_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'],  4, 4)) / 100000;
 159                                         $thisfile_png_chunk_type_text['red_y']   = getid3_lib::BigEndian2Int(substr($chunk['data'],  8, 4)) / 100000;
 160                                         $thisfile_png_chunk_type_text['red_y']   = getid3_lib::BigEndian2Int(substr($chunk['data'], 12, 4)) / 100000;
 161                                         $thisfile_png_chunk_type_text['green_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 16, 4)) / 100000;
 162                                         $thisfile_png_chunk_type_text['green_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 20, 4)) / 100000;
 163                                         $thisfile_png_chunk_type_text['blue_y']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 24, 4)) / 100000;
 164                                         $thisfile_png_chunk_type_text['blue_y']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 28, 4)) / 100000;
 165                                         break;
 166
 167
 168                                 case 'sRGB': // Standard RGB Color Space
 169                                         $thisfile_png_chunk_type_text['header']                 = $chunk;
 170                                         $thisfile_png_chunk_type_text['reindering_intent']      = getid3_lib::BigEndian2Int($chunk['data']);
 171                                         $thisfile_png_chunk_type_text['reindering_intent_text'] = $this->PNGsRGBintentLookup($thisfile_png_chunk_type_text['reindering_intent']);
 172                                         break;
 173
 174
 175                                 case 'iCCP': // Embedded ICC Profile
 176                                         $thisfile_png_chunk_type_text['header']                  = $chunk;
 177                                         list($profilename, $compressiondata)                     = explode("\x00", $chunk['data'], 2);
 178                                         $thisfile_png_chunk_type_text['profile_name']            = $profilename;
 179                                         $thisfile_png_chunk_type_text['compression_method']      = getid3_lib::BigEndian2Int(substr($compressiondata, 0, 1));
 180                                         $thisfile_png_chunk_type_text['compression_profile']     = substr($compressiondata, 1);
 181
 182                                         $thisfile_png_chunk_type_text['compression_method_text'] = $this->PNGcompressionMethodLookup($thisfile_png_chunk_type_text['compression_method']);
 183                                         break;
 184
 185
 186                                 case 'tEXt': // Textual Data
 187                                         $thisfile_png_chunk_type_text['header']  = $chunk;
 188                                         list($keyword, $text) = explode("\x00", $chunk['data'], 2);
 189                                         $thisfile_png_chunk_type_text['keyword'] = $keyword;
 190                                         $thisfile_png_chunk_type_text['text']    = $text;
 191
 192                                         $thisfile_png['comments'][$thisfile_png_chunk_type_text['keyword']][] = $thisfile_png_chunk_type_text['text'];
 193                                         break;
 194
 195
 196                                 case 'zTXt': // Compressed Textual Data
 197                                         $thisfile_png_chunk_type_text['header']                  = $chunk;
 198                                         list($keyword, $otherdata)                               = explode("\x00", $chunk['data'], 2);
 199                                         $thisfile_png_chunk_type_text['keyword']                 = $keyword;
 200                                         $thisfile_png_chunk_type_text['compression_method']      = getid3_lib::BigEndian2Int(substr($otherdata, 0, 1));
 201                                         $thisfile_png_chunk_type_text['compressed_text']         = substr($otherdata, 1);
 202                                         $thisfile_png_chunk_type_text['compression_method_text'] = $this->PNGcompressionMethodLookup($thisfile_png_chunk_type_text['compression_method']);
 203                                         switch ($thisfile_png_chunk_type_text['compression_method']) {
 204                                                 case 0:
 205                                                         $thisfile_png_chunk_type_text['text']            = gzuncompress($thisfile_png_chunk_type_text['compressed_text']);
 206                                                         break;
 207
 208                                                 default:
 209                                                         // unknown compression method
 210                                                         break;
 211                                         }
 212
 213                                         if (isset($thisfile_png_chunk_type_text['text'])) {
 214                                                 $thisfile_png['comments'][$thisfile_png_chunk_type_text['keyword']][] = $thisfile_png_chunk_type_text['text'];
 215                                         }
 216                                         break;
 217
 218
 219                                 case 'iTXt': // International Textual Data
 220                                         $thisfile_png_chunk_type_text['header']                  = $chunk;
 221                                         list($keyword, $otherdata)                               = explode("\x00", $chunk['data'], 2);
 222                                         $thisfile_png_chunk_type_text['keyword']                 = $keyword;
 223                                         $thisfile_png_chunk_type_text['compression']             = (bool) getid3_lib::BigEndian2Int(substr($otherdata, 0, 1));
 224                                         $thisfile_png_chunk_type_text['compression_method']      = getid3_lib::BigEndian2Int(substr($otherdata, 1, 1));
 225                                         $thisfile_png_chunk_type_text['compression_method_text'] = $this->PNGcompressionMethodLookup($thisfile_png_chunk_type_text['compression_method']);
 226                                         list($languagetag, $translatedkeyword, $text)                        = explode("\x00", substr($otherdata, 2), 3);
 227                                         $thisfile_png_chunk_type_text['language_tag']            = $languagetag;
 228                                         $thisfile_png_chunk_type_text['translated_keyword']      = $translatedkeyword;
 229
 230                                         if ($thisfile_png_chunk_type_text['compression']) {
 231
 232                                                 switch ($thisfile_png_chunk_type_text['compression_method']) {
 233                                                         case 0:
 234                                                                 $thisfile_png_chunk_type_text['text']        = gzuncompress($text);
 235                                                                 break;
 236
 237                                                         default:
 238                                                                 // unknown compression method
 239                                                                 break;
 240                                                 }
 241
 242                                         } else {
 243
 244                                                 $thisfile_png_chunk_type_text['text']                = $text;
 245
 246                                         }
 247
 248                                         if (isset($thisfile_png_chunk_type_text['text'])) {
 249                                                 $thisfile_png['comments'][$thisfile_png_chunk_type_text['keyword']][] = $thisfile_png_chunk_type_text['text'];
 250                                         }
 251                                         break;
 252
 253
 254                                 case 'bKGD': // Background Color
 255                                         $thisfile_png_chunk_type_text['header']                   = $chunk;
 256                                         switch ($thisfile_png['IHDR']['raw']['color_type']) {
 257                                                 case 0:
 258                                                 case 4:
 259                                                         $thisfile_png_chunk_type_text['background_gray']  = getid3_lib::BigEndian2Int($chunk['data']);
 260                                                         break;
 261
 262                                                 case 2:
 263                                                 case 6:
 264                                                         $thisfile_png_chunk_type_text['background_red']   = getid3_lib::BigEndian2Int(substr($chunk['data'], 0 * $thisfile_png['IHDR']['raw']['bit_depth'], $thisfile_png['IHDR']['raw']['bit_depth']));
 265                                                         $thisfile_png_chunk_type_text['background_green'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1 * $thisfile_png['IHDR']['raw']['bit_depth'], $thisfile_png['IHDR']['raw']['bit_depth']));
 266                                                         $thisfile_png_chunk_type_text['background_blue']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 2 * $thisfile_png['IHDR']['raw']['bit_depth'], $thisfile_png['IHDR']['raw']['bit_depth']));
 267                                                         break;
 268
 269                                                 case 3:
 270                                                         $thisfile_png_chunk_type_text['background_index'] = getid3_lib::BigEndian2Int($chunk['data']);
 271                                                         break;
 272
 273                                                 default:
 274                                                         break;
 275                                         }
 276                                         break;
 277
 278
 279                                 case 'pHYs': // Physical Pixel Dimensions
 280                                         $thisfile_png_chunk_type_text['header']                 = $chunk;
 281                                         $thisfile_png_chunk_type_text['pixels_per_unit_x']      = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 4));
 282                                         $thisfile_png_chunk_type_text['pixels_per_unit_y']      = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 4));
 283                                         $thisfile_png_chunk_type_text['unit_specifier']         = getid3_lib::BigEndian2Int(substr($chunk['data'], 8, 1));
 284                                         $thisfile_png_chunk_type_text['unit']                   = $this->PNGpHYsUnitLookup($thisfile_png_chunk_type_text['unit_specifier']);
 285                                         break;
 286
 287
 288                                 case 'sBIT': // Significant Bits
 289                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 290                                         switch ($thisfile_png['IHDR']['raw']['color_type']) {
 291                                                 case 0:
 292                                                         $thisfile_png_chunk_type_text['significant_bits_gray']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1));
 293                                                         break;
 294
 295                                                 case 2:
 296                                                 case 3:
 297                                                         $thisfile_png_chunk_type_text['significant_bits_red']   = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1));
 298                                                         $thisfile_png_chunk_type_text['significant_bits_green'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1, 1));
 299                                                         $thisfile_png_chunk_type_text['significant_bits_blue']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 1));
 300                                                         break;
 301
 302                                                 case 4:
 303                                                         $thisfile_png_chunk_type_text['significant_bits_gray']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1));
 304                                                         $thisfile_png_chunk_type_text['significant_bits_alpha'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1, 1));
 305                                                         break;
 306
 307                                                 case 6:
 308                                                         $thisfile_png_chunk_type_text['significant_bits_red']   = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1));
 309                                                         $thisfile_png_chunk_type_text['significant_bits_green'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1, 1));
 310                                                         $thisfile_png_chunk_type_text['significant_bits_blue']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 1));
 311                                                         $thisfile_png_chunk_type_text['significant_bits_alpha'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 3, 1));
 312                                                         break;
 313
 314                                                 default:
 315                                                         break;
 316                                         }
 317                                         break;
 318
 319
 320                                 case 'sPLT': // Suggested Palette
 321                                         $thisfile_png_chunk_type_text['header']                           = $chunk;
 322                                         list($palettename, $otherdata)                                    = explode("\x00", $chunk['data'], 2);
 323                                         $thisfile_png_chunk_type_text['palette_name']                     = $palettename;
 324                                         $sPLToffset = 0;
 325                                         $thisfile_png_chunk_type_text['sample_depth_bits']                = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, 1));
 326                                         $sPLToffset += 1;
 327                                         $thisfile_png_chunk_type_text['sample_depth_bytes']               = $thisfile_png_chunk_type_text['sample_depth_bits'] / 8;
 328                                         $paletteCounter = 0;
 329                                         while ($sPLToffset < strlen($otherdata)) {
 330                                                 $thisfile_png_chunk_type_text['red'][$paletteCounter]       = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, $thisfile_png_chunk_type_text['sample_depth_bytes']));
 331                                                 $sPLToffset += $thisfile_png_chunk_type_text['sample_depth_bytes'];
 332                                                 $thisfile_png_chunk_type_text['green'][$paletteCounter]     = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, $thisfile_png_chunk_type_text['sample_depth_bytes']));
 333                                                 $sPLToffset += $thisfile_png_chunk_type_text['sample_depth_bytes'];
 334                                                 $thisfile_png_chunk_type_text['blue'][$paletteCounter]      = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, $thisfile_png_chunk_type_text['sample_depth_bytes']));
 335                                                 $sPLToffset += $thisfile_png_chunk_type_text['sample_depth_bytes'];
 336                                                 $thisfile_png_chunk_type_text['alpha'][$paletteCounter]     = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, $thisfile_png_chunk_type_text['sample_depth_bytes']));
 337                                                 $sPLToffset += $thisfile_png_chunk_type_text['sample_depth_bytes'];
 338                                                 $thisfile_png_chunk_type_text['frequency'][$paletteCounter] = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, 2));
 339                                                 $sPLToffset += 2;
 340                                                 $paletteCounter++;
 341                                         }
 342                                         break;
 343
 344
 345                                 case 'hIST': // Palette Histogram
 346                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 347                                         $hISTcounter = 0;
 348                                         while ($hISTcounter < strlen($chunk['data'])) {
 349                                                 $thisfile_png_chunk_type_text[$hISTcounter] = getid3_lib::BigEndian2Int(substr($chunk['data'], $hISTcounter / 2, 2));
 350                                                 $hISTcounter += 2;
 351                                         }
 352                                         break;
 353
 354
 355                                 case 'tIME': // Image Last-Modification Time
 356                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 357                                         $thisfile_png_chunk_type_text['year']   = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 2));
 358                                         $thisfile_png_chunk_type_text['month']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 1));
 359                                         $thisfile_png_chunk_type_text['day']    = getid3_lib::BigEndian2Int(substr($chunk['data'], 3, 1));
 360                                         $thisfile_png_chunk_type_text['hour']   = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 1));
 361                                         $thisfile_png_chunk_type_text['minute'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 5, 1));
 362                                         $thisfile_png_chunk_type_text['second'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 6, 1));
 363                                         $thisfile_png_chunk_type_text['unix']   = gmmktime($thisfile_png_chunk_type_text['hour'], $thisfile_png_chunk_type_text['minute'], $thisfile_png_chunk_type_text['second'], $thisfile_png_chunk_type_text['month'], $thisfile_png_chunk_type_text['day'], $thisfile_png_chunk_type_text['year']);
 364                                         break;
 365
 366
 367                                 case 'oFFs': // Image Offset
 368                                         $thisfile_png_chunk_type_text['header']         = $chunk;
 369                                         $thisfile_png_chunk_type_text['position_x']     = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 4), false, true);
 370                                         $thisfile_png_chunk_type_text['position_y']     = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 4), false, true);
 371                                         $thisfile_png_chunk_type_text['unit_specifier'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 8, 1));
 372                                         $thisfile_png_chunk_type_text['unit']           = $this->PNGoFFsUnitLookup($thisfile_png_chunk_type_text['unit_specifier']);
 373                                         break;
 374
 375
 376                                 case 'pCAL': // Calibration Of Pixel Values
 377                                         $thisfile_png_chunk_type_text['header']             = $chunk;
 378                                         list($calibrationname, $otherdata)                              = explode("\x00", $chunk['data'], 2);
 379                                         $thisfile_png_chunk_type_text['calibration_name']   = $calibrationname;
 380                                         $pCALoffset = 0;
 381                                         $thisfile_png_chunk_type_text['original_zero']      = getid3_lib::BigEndian2Int(substr($chunk['data'], $pCALoffset, 4), false, true);
 382                                         $pCALoffset += 4;
 383                                         $thisfile_png_chunk_type_text['original_max']       = getid3_lib::BigEndian2Int(substr($chunk['data'], $pCALoffset, 4), false, true);
 384                                         $pCALoffset += 4;
 385                                         $thisfile_png_chunk_type_text['equation_type']      = getid3_lib::BigEndian2Int(substr($chunk['data'], $pCALoffset, 1));
 386                                         $pCALoffset += 1;
 387                                         $thisfile_png_chunk_type_text['equation_type_text'] = $this->PNGpCALequationTypeLookup($thisfile_png_chunk_type_text['equation_type']);
 388                                         $thisfile_png_chunk_type_text['parameter_count']    = getid3_lib::BigEndian2Int(substr($chunk['data'], $pCALoffset, 1));
 389                                         $pCALoffset += 1;
 390                                         $thisfile_png_chunk_type_text['parameters']         = explode("\x00", substr($chunk['data'], $pCALoffset));
 391                                         break;
 392
 393
 394                                 case 'sCAL': // Physical Scale Of Image Subject
 395                                         $thisfile_png_chunk_type_text['header']         = $chunk;
 396                                         $thisfile_png_chunk_type_text['unit_specifier'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1));
 397                                         $thisfile_png_chunk_type_text['unit']           = $this->PNGsCALUnitLookup($thisfile_png_chunk_type_text['unit_specifier']);
 398                                         list($pixelwidth, $pixelheight)                             = explode("\x00", substr($chunk['data'], 1));
 399                                         $thisfile_png_chunk_type_text['pixel_width']    = $pixelwidth;
 400                                         $thisfile_png_chunk_type_text['pixel_height']   = $pixelheight;
 401                                         break;
 402
 403
 404                                 case 'gIFg': // GIF Graphic Control Extension
 405                                         $gIFgCounter = 0;
 406                                         if (isset($thisfile_png_chunk_type_text) && is_array($thisfile_png_chunk_type_text)) {
 407                                                 $gIFgCounter = count($thisfile_png_chunk_type_text);
 408                                         }
 409                                         $thisfile_png_chunk_type_text[$gIFgCounter]['header']          = $chunk;
 410                                         $thisfile_png_chunk_type_text[$gIFgCounter]['disposal_method'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1));
 411                                         $thisfile_png_chunk_type_text[$gIFgCounter]['user_input_flag'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1, 1));
 412                                         $thisfile_png_chunk_type_text[$gIFgCounter]['delay_time']      = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 2));
 413                                         break;
 414
 415
 416                                 case 'gIFx': // GIF Application Extension
 417                                         $gIFxCounter = 0;
 418                                         if (isset($thisfile_png_chunk_type_text) && is_array($thisfile_png_chunk_type_text)) {
 419                                                 $gIFxCounter = count($thisfile_png_chunk_type_text);
 420                                         }
 421                                         $thisfile_png_chunk_type_text[$gIFxCounter]['header']                 = $chunk;
 422                                         $thisfile_png_chunk_type_text[$gIFxCounter]['application_identifier'] = substr($chunk['data'],  0, 8);
 423                                         $thisfile_png_chunk_type_text[$gIFxCounter]['authentication_code']    = substr($chunk['data'],  8, 3);
 424                                         $thisfile_png_chunk_type_text[$gIFxCounter]['application_data']       = substr($chunk['data'], 11);
 425                                         break;
 426
 427
 428                                 case 'IDAT': // Image Data
 429                                         $idatinformationfieldindex = 0;
 430                                         if (isset($thisfile_png['IDAT']) && is_array($thisfile_png['IDAT'])) {
 431                                                 $idatinformationfieldindex = count($thisfile_png['IDAT']);
 432                                         }
 433                                         unset($chunk['data']);
 434                                         $thisfile_png_chunk_type_text[$idatinformationfieldindex]['header'] = $chunk;
 435                                         break;
 436
 437
 438                                 case 'IEND': // Image Trailer
 439                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 440                                         break;
 441
 442
 443                                 default:
 444                                         //unset($chunk['data']);
 445                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 446                                         $this->warning('Unhandled chunk type: '.$chunk['type_text']);
 447                                         break;
 448                         }
 449                 }
 450
 451                 return true;
 452         }
 453
 454         public function PNGsRGBintentLookup($sRGB) {
 455                 static $PNGsRGBintentLookup = array(
 456                         0 => 'Perceptual',
 457                         1 => 'Relative colorimetric',
 458                         2 => 'Saturation',
 459                         3 => 'Absolute colorimetric'
 460                 );
 461                 return (isset($PNGsRGBintentLookup[$sRGB]) ? $PNGsRGBintentLookup[$sRGB] : 'invalid');
 462         }
 463
 464         public function PNGcompressionMethodLookup($compressionmethod) {
 465                 static $PNGcompressionMethodLookup = array(
 466                         0 => 'deflate/inflate'
 467                 );
 468                 return (isset($PNGcompressionMethodLookup[$compressionmethod]) ? $PNGcompressionMethodLookup[$compressionmethod] : 'invalid');
 469         }
 470
 471         public function PNGpHYsUnitLookup($unitid) {
 472                 static $PNGpHYsUnitLookup = array(
 473                         0 => 'unknown',
 474                         1 => 'meter'
 475                 );
 476                 return (isset($PNGpHYsUnitLookup[$unitid]) ? $PNGpHYsUnitLookup[$unitid] : 'invalid');
 477         }
 478
 479         public function PNGoFFsUnitLookup($unitid) {
 480                 static $PNGoFFsUnitLookup = array(
 481                         0 => 'pixel',
 482                         1 => 'micrometer'
 483                 );
 484                 return (isset($PNGoFFsUnitLookup[$unitid]) ? $PNGoFFsUnitLookup[$unitid] : 'invalid');
 485         }
 486
 487         public function PNGpCALequationTypeLookup($equationtype) {
 488                 static $PNGpCALequationTypeLookup = array(
 489                         0 => 'Linear mapping',
 490                         1 => 'Base-e exponential mapping',
 491                         2 => 'Arbitrary-base exponential mapping',
 492                         3 => 'Hyperbolic mapping'
 493                 );
 494                 return (isset($PNGpCALequationTypeLookup[$equationtype]) ? $PNGpCALequationTypeLookup[$equationtype] : 'invalid');
 495         }
 496
 497         public function PNGsCALUnitLookup($unitid) {
 498                 static $PNGsCALUnitLookup = array(
 499                         0 => 'meter',
 500                         1 => 'radian'
 501                 );
 502                 return (isset($PNGsCALUnitLookup[$unitid]) ? $PNGsCALUnitLookup[$unitid] : 'invalid');
 503         }
 504
 505         public function IHDRcalculateBitsPerSample($color_type, $bit_depth) {
 506                 switch ($color_type) {
 507                         case 0: // Each pixel is a grayscale sample.
 508                                 return $bit_depth;
 509                                 break;
 510
 511                         case 2: // Each pixel is an R,G,B triple
 512                                 return 3 * $bit_depth;
 513                                 break;
 514
 515                         case 3: // Each pixel is a palette index; a PLTE chunk must appear.
 516                                 return $bit_depth;
 517                                 break;
 518
 519                         case 4: // Each pixel is a grayscale sample, followed by an alpha sample.
 520                                 return 2 * $bit_depth;
 521                                 break;
 522
 523                         case 6: // Each pixel is an R,G,B triple, followed by an alpha sample.
 524                                 return 4 * $bit_depth;
 525                                 break;
 526                 }
 527                 return false;
 528         }
 529
 530 }