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

   1 <?php
   2
   3 /////////////////////////////////////////////////////////////////
   4 /// getID3() by James Heinrich <info@getid3.org>               //
   5 //  available at https://github.com/JamesHeinrich/getID3       //
   6 //            or https://www.getid3.org                        //
   7 //            or http://getid3.sourceforge.net                 //
   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 if (!defined('GETID3_INCLUDEPATH')) { // prevent path-exposing attacks that access modules directly on public webservers
  18         exit;
  19 }
  20
  21 class getid3_png extends getid3_handler
  22 {
  23         /**
  24          * If data chunk is larger than this do not read it completely (getID3 only needs the first
  25          * few dozen bytes for parsing).
  26          *
  27          * @var int
  28          */
  29         public $max_data_bytes = 10000000;
  30
  31         /**
  32          * @return bool
  33          */
  34         public function Analyze() {
  35
  36                 $info = &$this->getid3->info;
  37
  38                 // shortcut
  39                 $info['png'] = array();
  40                 $thisfile_png = &$info['png'];
  41
  42                 $info['fileformat']          = 'png';
  43                 $info['video']['dataformat'] = 'png';
  44                 $info['video']['lossless']   = false;
  45
  46                 $this->fseek($info['avdataoffset']);
  47                 $PNGfiledata = $this->fread($this->getid3->fread_buffer_size());
  48                 $offset = 0;
  49
  50                 $PNGidentifier = substr($PNGfiledata, $offset, 8); // $89 $50 $4E $47 $0D $0A $1A $0A
  51                 $offset += 8;
  52
  53                 if ($PNGidentifier != "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A") {
  54                         $this->error('First 8 bytes of file ('.getid3_lib::PrintHexBytes($PNGidentifier).') did not match expected PNG identifier');
  55                         unset($info['fileformat']);
  56                         return false;
  57                 }
  58
  59                 while ((($this->ftell() - (strlen($PNGfiledata) - $offset)) < $info['filesize'])) {
  60                         $chunk['data_length'] = getid3_lib::BigEndian2Int(substr($PNGfiledata, $offset, 4));
  61                         if ($chunk['data_length'] === false) {
  62                                 $this->error('Failed to read data_length at offset '.$offset);
  63                                 return false;
  64                         }
  65                         $offset += 4;
  66                         $truncated_data = false;
  67                         while (((strlen($PNGfiledata) - $offset) < ($chunk['data_length'] + 4)) && ($this->ftell() < $info['filesize'])) {
  68                                 if (strlen($PNGfiledata) < $this->max_data_bytes) {
  69                                         $PNGfiledata .= $this->fread($this->getid3->fread_buffer_size());
  70                                 } else {
  71                                         $this->warning('At offset '.$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');
  72                                         break;
  73                                 }
  74                         }
  75                         $chunk['type_text']   =                           substr($PNGfiledata, $offset, 4);
  76                         $offset += 4;
  77                         $chunk['type_raw']    = getid3_lib::BigEndian2Int($chunk['type_text']);
  78                         $chunk['data']        =                           substr($PNGfiledata, $offset, $chunk['data_length']);
  79                         $offset += $chunk['data_length'];
  80                         $chunk['crc']         = getid3_lib::BigEndian2Int(substr($PNGfiledata, $offset, 4));
  81                         $offset += 4;
  82
  83                         $chunk['flags']['ancilliary']   = (bool) ($chunk['type_raw'] & 0x20000000);
  84                         $chunk['flags']['private']      = (bool) ($chunk['type_raw'] & 0x00200000);
  85                         $chunk['flags']['reserved']     = (bool) ($chunk['type_raw'] & 0x00002000);
  86                         $chunk['flags']['safe_to_copy'] = (bool) ($chunk['type_raw'] & 0x00000020);
  87
  88                         // shortcut
  89                         $thisfile_png[$chunk['type_text']] = array();
  90                         $thisfile_png_chunk_type_text = &$thisfile_png[$chunk['type_text']];
  91
  92                         switch ($chunk['type_text']) {
  93
  94                                 case 'IHDR': // Image Header
  95                                         $thisfile_png_chunk_type_text['header'] = $chunk;
  96                                         $thisfile_png_chunk_type_text['width']                     = getid3_lib::BigEndian2Int(substr($chunk['data'],  0, 4));
  97                                         $thisfile_png_chunk_type_text['height']                    = getid3_lib::BigEndian2Int(substr($chunk['data'],  4, 4));
  98                                         $thisfile_png_chunk_type_text['raw']['bit_depth']          = getid3_lib::BigEndian2Int(substr($chunk['data'],  8, 1));
  99                                         $thisfile_png_chunk_type_text['raw']['color_type']         = getid3_lib::BigEndian2Int(substr($chunk['data'],  9, 1));
 100                                         $thisfile_png_chunk_type_text['raw']['compression_method'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 10, 1));
 101                                         $thisfile_png_chunk_type_text['raw']['filter_method']      = getid3_lib::BigEndian2Int(substr($chunk['data'], 11, 1));
 102                                         $thisfile_png_chunk_type_text['raw']['interlace_method']   = getid3_lib::BigEndian2Int(substr($chunk['data'], 12, 1));
 103
 104                                         $thisfile_png_chunk_type_text['compression_method_text']   = $this->PNGcompressionMethodLookup($thisfile_png_chunk_type_text['raw']['compression_method']);
 105                                         $thisfile_png_chunk_type_text['color_type']['palette']     = (bool) ($thisfile_png_chunk_type_text['raw']['color_type'] & 0x01);
 106                                         $thisfile_png_chunk_type_text['color_type']['true_color']  = (bool) ($thisfile_png_chunk_type_text['raw']['color_type'] & 0x02);
 107                                         $thisfile_png_chunk_type_text['color_type']['alpha']       = (bool) ($thisfile_png_chunk_type_text['raw']['color_type'] & 0x04);
 108
 109                                         $info['video']['resolution_x']    = $thisfile_png_chunk_type_text['width'];
 110                                         $info['video']['resolution_y']    = $thisfile_png_chunk_type_text['height'];
 111
 112                                         $info['video']['bits_per_sample'] = $this->IHDRcalculateBitsPerSample($thisfile_png_chunk_type_text['raw']['color_type'], $thisfile_png_chunk_type_text['raw']['bit_depth']);
 113                                         break;
 114
 115
 116                                 case 'PLTE': // Palette
 117                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 118                                         $paletteoffset = 0;
 119                                         for ($i = 0; $i <= 255; $i++) {
 120                                                 //$thisfile_png_chunk_type_text['red'][$i]   = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1));
 121                                                 //$thisfile_png_chunk_type_text['green'][$i] = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1));
 122                                                 //$thisfile_png_chunk_type_text['blue'][$i]  = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1));
 123                                                 $red   = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1));
 124                                                 $green = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1));
 125                                                 $blue  = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1));
 126                                                 $thisfile_png_chunk_type_text[$i] = (($red << 16) | ($green << 8) | ($blue));
 127                                         }
 128                                         break;
 129
 130
 131                                 case 'tRNS': // Transparency
 132                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 133                                         switch ($thisfile_png['IHDR']['raw']['color_type']) {
 134                                                 case 0:
 135                                                         $thisfile_png_chunk_type_text['transparent_color_gray']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 2));
 136                                                         break;
 137
 138                                                 case 2:
 139                                                         $thisfile_png_chunk_type_text['transparent_color_red']   = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 2));
 140                                                         $thisfile_png_chunk_type_text['transparent_color_green'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 2));
 141                                                         $thisfile_png_chunk_type_text['transparent_color_blue']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 2));
 142                                                         break;
 143
 144                                                 case 3:
 145                                                         for ($i = 0; $i < strlen($chunk['data']); $i++) {
 146                                                                 $thisfile_png_chunk_type_text['palette_opacity'][$i] = getid3_lib::BigEndian2Int(substr($chunk['data'], $i, 1));
 147                                                         }
 148                                                         break;
 149
 150                                                 case 4:
 151                                                 case 6:
 152                                                         $this->error('Invalid color_type in tRNS chunk: '.$thisfile_png['IHDR']['raw']['color_type']);
 153                                                         break;
 154
 155                                                 default:
 156                                                         $this->warning('Unhandled color_type in tRNS chunk: '.$thisfile_png['IHDR']['raw']['color_type']);
 157                                                         break;
 158                                         }
 159                                         break;
 160
 161
 162                                 case 'gAMA': // Image Gamma
 163                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 164                                         $thisfile_png_chunk_type_text['gamma']  = getid3_lib::BigEndian2Int($chunk['data']) / 100000;
 165                                         break;
 166
 167
 168                                 case 'cHRM': // Primary Chromaticities
 169                                         $thisfile_png_chunk_type_text['header']  = $chunk;
 170                                         $thisfile_png_chunk_type_text['white_x'] = getid3_lib::BigEndian2Int(substr($chunk['data'],  0, 4)) / 100000;
 171                                         $thisfile_png_chunk_type_text['white_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'],  4, 4)) / 100000;
 172                                         $thisfile_png_chunk_type_text['red_y']   = getid3_lib::BigEndian2Int(substr($chunk['data'],  8, 4)) / 100000;
 173                                         $thisfile_png_chunk_type_text['red_y']   = getid3_lib::BigEndian2Int(substr($chunk['data'], 12, 4)) / 100000;
 174                                         $thisfile_png_chunk_type_text['green_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 16, 4)) / 100000;
 175                                         $thisfile_png_chunk_type_text['green_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 20, 4)) / 100000;
 176                                         $thisfile_png_chunk_type_text['blue_y']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 24, 4)) / 100000;
 177                                         $thisfile_png_chunk_type_text['blue_y']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 28, 4)) / 100000;
 178                                         break;
 179
 180
 181                                 case 'sRGB': // Standard RGB Color Space
 182                                         $thisfile_png_chunk_type_text['header']                 = $chunk;
 183                                         $thisfile_png_chunk_type_text['reindering_intent']      = getid3_lib::BigEndian2Int($chunk['data']);
 184                                         $thisfile_png_chunk_type_text['reindering_intent_text'] = $this->PNGsRGBintentLookup($thisfile_png_chunk_type_text['reindering_intent']);
 185                                         break;
 186
 187
 188                                 case 'iCCP': // Embedded ICC Profile
 189                                         $thisfile_png_chunk_type_text['header']                  = $chunk;
 190                                         list($profilename, $compressiondata)                     = explode("\x00", $chunk['data'], 2);
 191                                         $thisfile_png_chunk_type_text['profile_name']            = $profilename;
 192                                         $thisfile_png_chunk_type_text['compression_method']      = getid3_lib::BigEndian2Int(substr($compressiondata, 0, 1));
 193                                         $thisfile_png_chunk_type_text['compression_profile']     = substr($compressiondata, 1);
 194
 195                                         $thisfile_png_chunk_type_text['compression_method_text'] = $this->PNGcompressionMethodLookup($thisfile_png_chunk_type_text['compression_method']);
 196                                         break;
 197
 198
 199                                 case 'tEXt': // Textual Data
 200                                         $thisfile_png_chunk_type_text['header']  = $chunk;
 201                                         list($keyword, $text) = explode("\x00", $chunk['data'], 2);
 202                                         $thisfile_png_chunk_type_text['keyword'] = $keyword;
 203                                         $thisfile_png_chunk_type_text['text']    = $text;
 204
 205                                         $thisfile_png['comments'][$thisfile_png_chunk_type_text['keyword']][] = $thisfile_png_chunk_type_text['text'];
 206                                         break;
 207
 208
 209                                 case 'zTXt': // Compressed Textual Data
 210                                         $thisfile_png_chunk_type_text['header']                  = $chunk;
 211                                         list($keyword, $otherdata)                               = explode("\x00", $chunk['data'], 2);
 212                                         $thisfile_png_chunk_type_text['keyword']                 = $keyword;
 213                                         $thisfile_png_chunk_type_text['compression_method']      = getid3_lib::BigEndian2Int(substr($otherdata, 0, 1));
 214                                         $thisfile_png_chunk_type_text['compressed_text']         = substr($otherdata, 1);
 215                                         $thisfile_png_chunk_type_text['compression_method_text'] = $this->PNGcompressionMethodLookup($thisfile_png_chunk_type_text['compression_method']);
 216                                         switch ($thisfile_png_chunk_type_text['compression_method']) {
 217                                                 case 0:
 218                                                         $thisfile_png_chunk_type_text['text']            = gzuncompress($thisfile_png_chunk_type_text['compressed_text']);
 219                                                         break;
 220
 221                                                 default:
 222                                                         // unknown compression method
 223                                                         break;
 224                                         }
 225
 226                                         if (isset($thisfile_png_chunk_type_text['text'])) {
 227                                                 $thisfile_png['comments'][$thisfile_png_chunk_type_text['keyword']][] = $thisfile_png_chunk_type_text['text'];
 228                                         }
 229                                         break;
 230
 231
 232                                 case 'iTXt': // International Textual Data
 233                                         $thisfile_png_chunk_type_text['header']                  = $chunk;
 234                                         list($keyword, $otherdata)                               = explode("\x00", $chunk['data'], 2);
 235                                         $thisfile_png_chunk_type_text['keyword']                 = $keyword;
 236                                         $thisfile_png_chunk_type_text['compression']             = (bool) getid3_lib::BigEndian2Int(substr($otherdata, 0, 1));
 237                                         $thisfile_png_chunk_type_text['compression_method']      = getid3_lib::BigEndian2Int(substr($otherdata, 1, 1));
 238                                         $thisfile_png_chunk_type_text['compression_method_text'] = $this->PNGcompressionMethodLookup($thisfile_png_chunk_type_text['compression_method']);
 239                                         list($languagetag, $translatedkeyword, $text)                        = explode("\x00", substr($otherdata, 2), 3);
 240                                         $thisfile_png_chunk_type_text['language_tag']            = $languagetag;
 241                                         $thisfile_png_chunk_type_text['translated_keyword']      = $translatedkeyword;
 242
 243                                         if ($thisfile_png_chunk_type_text['compression']) {
 244
 245                                                 switch ($thisfile_png_chunk_type_text['compression_method']) {
 246                                                         case 0:
 247                                                                 $thisfile_png_chunk_type_text['text']        = gzuncompress($text);
 248                                                                 break;
 249
 250                                                         default:
 251                                                                 // unknown compression method
 252                                                                 break;
 253                                                 }
 254
 255                                         } else {
 256
 257                                                 $thisfile_png_chunk_type_text['text']                = $text;
 258
 259                                         }
 260
 261                                         if (isset($thisfile_png_chunk_type_text['text'])) {
 262                                                 $thisfile_png['comments'][$thisfile_png_chunk_type_text['keyword']][] = $thisfile_png_chunk_type_text['text'];
 263                                         }
 264                                         break;
 265
 266
 267                                 case 'bKGD': // Background Color
 268                                         $thisfile_png_chunk_type_text['header']                   = $chunk;
 269                                         switch ($thisfile_png['IHDR']['raw']['color_type']) {
 270                                                 case 0:
 271                                                 case 4:
 272                                                         $thisfile_png_chunk_type_text['background_gray']  = getid3_lib::BigEndian2Int($chunk['data']);
 273                                                         break;
 274
 275                                                 case 2:
 276                                                 case 6:
 277                                                         $thisfile_png_chunk_type_text['background_red']   = getid3_lib::BigEndian2Int(substr($chunk['data'], 0 * $thisfile_png['IHDR']['raw']['bit_depth'], $thisfile_png['IHDR']['raw']['bit_depth']));
 278                                                         $thisfile_png_chunk_type_text['background_green'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1 * $thisfile_png['IHDR']['raw']['bit_depth'], $thisfile_png['IHDR']['raw']['bit_depth']));
 279                                                         $thisfile_png_chunk_type_text['background_blue']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 2 * $thisfile_png['IHDR']['raw']['bit_depth'], $thisfile_png['IHDR']['raw']['bit_depth']));
 280                                                         break;
 281
 282                                                 case 3:
 283                                                         $thisfile_png_chunk_type_text['background_index'] = getid3_lib::BigEndian2Int($chunk['data']);
 284                                                         break;
 285
 286                                                 default:
 287                                                         break;
 288                                         }
 289                                         break;
 290
 291
 292                                 case 'pHYs': // Physical Pixel Dimensions
 293                                         $thisfile_png_chunk_type_text['header']                 = $chunk;
 294                                         $thisfile_png_chunk_type_text['pixels_per_unit_x']      = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 4));
 295                                         $thisfile_png_chunk_type_text['pixels_per_unit_y']      = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 4));
 296                                         $thisfile_png_chunk_type_text['unit_specifier']         = getid3_lib::BigEndian2Int(substr($chunk['data'], 8, 1));
 297                                         $thisfile_png_chunk_type_text['unit']                   = $this->PNGpHYsUnitLookup($thisfile_png_chunk_type_text['unit_specifier']);
 298                                         break;
 299
 300
 301                                 case 'sBIT': // Significant Bits
 302                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 303                                         switch ($thisfile_png['IHDR']['raw']['color_type']) {
 304                                                 case 0:
 305                                                         $thisfile_png_chunk_type_text['significant_bits_gray']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1));
 306                                                         break;
 307
 308                                                 case 2:
 309                                                 case 3:
 310                                                         $thisfile_png_chunk_type_text['significant_bits_red']   = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1));
 311                                                         $thisfile_png_chunk_type_text['significant_bits_green'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1, 1));
 312                                                         $thisfile_png_chunk_type_text['significant_bits_blue']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 1));
 313                                                         break;
 314
 315                                                 case 4:
 316                                                         $thisfile_png_chunk_type_text['significant_bits_gray']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1));
 317                                                         $thisfile_png_chunk_type_text['significant_bits_alpha'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1, 1));
 318                                                         break;
 319
 320                                                 case 6:
 321                                                         $thisfile_png_chunk_type_text['significant_bits_red']   = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1));
 322                                                         $thisfile_png_chunk_type_text['significant_bits_green'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1, 1));
 323                                                         $thisfile_png_chunk_type_text['significant_bits_blue']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 1));
 324                                                         $thisfile_png_chunk_type_text['significant_bits_alpha'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 3, 1));
 325                                                         break;
 326
 327                                                 default:
 328                                                         break;
 329                                         }
 330                                         break;
 331
 332
 333                                 case 'sPLT': // Suggested Palette
 334                                         $thisfile_png_chunk_type_text['header']                           = $chunk;
 335                                         list($palettename, $otherdata)                                    = explode("\x00", $chunk['data'], 2);
 336                                         $thisfile_png_chunk_type_text['palette_name']                     = $palettename;
 337                                         $sPLToffset = 0;
 338                                         $thisfile_png_chunk_type_text['sample_depth_bits']                = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, 1));
 339                                         $sPLToffset += 1;
 340                                         $thisfile_png_chunk_type_text['sample_depth_bytes']               = $thisfile_png_chunk_type_text['sample_depth_bits'] / 8;
 341                                         $paletteCounter = 0;
 342                                         while ($sPLToffset < strlen($otherdata)) {
 343                                                 $thisfile_png_chunk_type_text['red'][$paletteCounter]       = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, $thisfile_png_chunk_type_text['sample_depth_bytes']));
 344                                                 $sPLToffset += $thisfile_png_chunk_type_text['sample_depth_bytes'];
 345                                                 $thisfile_png_chunk_type_text['green'][$paletteCounter]     = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, $thisfile_png_chunk_type_text['sample_depth_bytes']));
 346                                                 $sPLToffset += $thisfile_png_chunk_type_text['sample_depth_bytes'];
 347                                                 $thisfile_png_chunk_type_text['blue'][$paletteCounter]      = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, $thisfile_png_chunk_type_text['sample_depth_bytes']));
 348                                                 $sPLToffset += $thisfile_png_chunk_type_text['sample_depth_bytes'];
 349                                                 $thisfile_png_chunk_type_text['alpha'][$paletteCounter]     = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, $thisfile_png_chunk_type_text['sample_depth_bytes']));
 350                                                 $sPLToffset += $thisfile_png_chunk_type_text['sample_depth_bytes'];
 351                                                 $thisfile_png_chunk_type_text['frequency'][$paletteCounter] = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, 2));
 352                                                 $sPLToffset += 2;
 353                                                 $paletteCounter++;
 354                                         }
 355                                         break;
 356
 357
 358                                 case 'hIST': // Palette Histogram
 359                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 360                                         $hISTcounter = 0;
 361                                         while ($hISTcounter < strlen($chunk['data'])) {
 362                                                 $thisfile_png_chunk_type_text[$hISTcounter] = getid3_lib::BigEndian2Int(substr($chunk['data'], $hISTcounter / 2, 2));
 363                                                 $hISTcounter += 2;
 364                                         }
 365                                         break;
 366
 367
 368                                 case 'tIME': // Image Last-Modification Time
 369                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 370                                         $thisfile_png_chunk_type_text['year']   = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 2));
 371                                         $thisfile_png_chunk_type_text['month']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 1));
 372                                         $thisfile_png_chunk_type_text['day']    = getid3_lib::BigEndian2Int(substr($chunk['data'], 3, 1));
 373                                         $thisfile_png_chunk_type_text['hour']   = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 1));
 374                                         $thisfile_png_chunk_type_text['minute'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 5, 1));
 375                                         $thisfile_png_chunk_type_text['second'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 6, 1));
 376                                         $thisfile_png_chunk_type_text['unix']   = gmmktime($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']);
 377                                         break;
 378
 379
 380                                 case 'oFFs': // Image Offset
 381                                         $thisfile_png_chunk_type_text['header']         = $chunk;
 382                                         $thisfile_png_chunk_type_text['position_x']     = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 4), false, true);
 383                                         $thisfile_png_chunk_type_text['position_y']     = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 4), false, true);
 384                                         $thisfile_png_chunk_type_text['unit_specifier'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 8, 1));
 385                                         $thisfile_png_chunk_type_text['unit']           = $this->PNGoFFsUnitLookup($thisfile_png_chunk_type_text['unit_specifier']);
 386                                         break;
 387
 388
 389                                 case 'pCAL': // Calibration Of Pixel Values
 390                                         $thisfile_png_chunk_type_text['header']             = $chunk;
 391                                         list($calibrationname, $otherdata)                              = explode("\x00", $chunk['data'], 2);
 392                                         $thisfile_png_chunk_type_text['calibration_name']   = $calibrationname;
 393                                         $pCALoffset = 0;
 394                                         $thisfile_png_chunk_type_text['original_zero']      = getid3_lib::BigEndian2Int(substr($chunk['data'], $pCALoffset, 4), false, true);
 395                                         $pCALoffset += 4;
 396                                         $thisfile_png_chunk_type_text['original_max']       = getid3_lib::BigEndian2Int(substr($chunk['data'], $pCALoffset, 4), false, true);
 397                                         $pCALoffset += 4;
 398                                         $thisfile_png_chunk_type_text['equation_type']      = getid3_lib::BigEndian2Int(substr($chunk['data'], $pCALoffset, 1));
 399                                         $pCALoffset += 1;
 400                                         $thisfile_png_chunk_type_text['equation_type_text'] = $this->PNGpCALequationTypeLookup($thisfile_png_chunk_type_text['equation_type']);
 401                                         $thisfile_png_chunk_type_text['parameter_count']    = getid3_lib::BigEndian2Int(substr($chunk['data'], $pCALoffset, 1));
 402                                         $pCALoffset += 1;
 403                                         $thisfile_png_chunk_type_text['parameters']         = explode("\x00", substr($chunk['data'], $pCALoffset));
 404                                         break;
 405
 406
 407                                 case 'sCAL': // Physical Scale Of Image Subject
 408                                         $thisfile_png_chunk_type_text['header']         = $chunk;
 409                                         $thisfile_png_chunk_type_text['unit_specifier'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1));
 410                                         $thisfile_png_chunk_type_text['unit']           = $this->PNGsCALUnitLookup($thisfile_png_chunk_type_text['unit_specifier']);
 411                                         list($pixelwidth, $pixelheight)                             = explode("\x00", substr($chunk['data'], 1));
 412                                         $thisfile_png_chunk_type_text['pixel_width']    = $pixelwidth;
 413                                         $thisfile_png_chunk_type_text['pixel_height']   = $pixelheight;
 414                                         break;
 415
 416
 417                                 case 'gIFg': // GIF Graphic Control Extension
 418                                         $gIFgCounter = 0;
 419                                         if (isset($thisfile_png_chunk_type_text) && is_array($thisfile_png_chunk_type_text)) {
 420                                                 $gIFgCounter = count($thisfile_png_chunk_type_text);
 421                                         }
 422                                         $thisfile_png_chunk_type_text[$gIFgCounter]['header']          = $chunk;
 423                                         $thisfile_png_chunk_type_text[$gIFgCounter]['disposal_method'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1));
 424                                         $thisfile_png_chunk_type_text[$gIFgCounter]['user_input_flag'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1, 1));
 425                                         $thisfile_png_chunk_type_text[$gIFgCounter]['delay_time']      = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 2));
 426                                         break;
 427
 428
 429                                 case 'gIFx': // GIF Application Extension
 430                                         $gIFxCounter = 0;
 431                                         if (isset($thisfile_png_chunk_type_text) && is_array($thisfile_png_chunk_type_text)) {
 432                                                 $gIFxCounter = count($thisfile_png_chunk_type_text);
 433                                         }
 434                                         $thisfile_png_chunk_type_text[$gIFxCounter]['header']                 = $chunk;
 435                                         $thisfile_png_chunk_type_text[$gIFxCounter]['application_identifier'] = substr($chunk['data'],  0, 8);
 436                                         $thisfile_png_chunk_type_text[$gIFxCounter]['authentication_code']    = substr($chunk['data'],  8, 3);
 437                                         $thisfile_png_chunk_type_text[$gIFxCounter]['application_data']       = substr($chunk['data'], 11);
 438                                         break;
 439
 440
 441                                 case 'IDAT': // Image Data
 442                                         $idatinformationfieldindex = 0;
 443                                         if (isset($thisfile_png['IDAT']) && is_array($thisfile_png['IDAT'])) {
 444                                                 $idatinformationfieldindex = count($thisfile_png['IDAT']);
 445                                         }
 446                                         unset($chunk['data']);
 447                                         $thisfile_png_chunk_type_text[$idatinformationfieldindex]['header'] = $chunk;
 448                                         break;
 449
 450                                 case 'IEND': // Image Trailer
 451                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 452                                         break;
 453
 454                                 case 'acTL': // Animation Control chunk
 455                                         // https://wiki.mozilla.org/APNG_Specification#.60acTL.60:_The_Animation_Control_Chunk
 456                                         $thisfile_png['animation']['num_frames'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 4)); // Number of frames
 457                                         $thisfile_png['animation']['num_plays']  = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 4)); // Number of times to loop this APNG.  0 indicates infinite looping.
 458
 459                                         unset($chunk['data']);
 460                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 461                                         break;
 462
 463                                 case 'fcTL': // Frame Control chunk
 464                                         // https://wiki.mozilla.org/APNG_Specification#.60fcTL.60:_The_Frame_Control_Chunk
 465                                         $fcTL = array();
 466                                         $fcTL['sequence_number'] = getid3_lib::BigEndian2Int(substr($chunk['data'],  0, 4)); // Sequence number of the animation chunk, starting from 0
 467                                         $fcTL['width']           = getid3_lib::BigEndian2Int(substr($chunk['data'],  4, 4)); // Width of the following frame
 468                                         $fcTL['height']          = getid3_lib::BigEndian2Int(substr($chunk['data'],  8, 4)); // Height of the following frame
 469                                         $fcTL['x_offset']        = getid3_lib::BigEndian2Int(substr($chunk['data'], 12, 4)); // X position at which to render the following frame
 470                                         $fcTL['y_offset']        = getid3_lib::BigEndian2Int(substr($chunk['data'], 16, 4)); // Y position at which to render the following frame
 471                                         $fcTL['delay_num']       = getid3_lib::BigEndian2Int(substr($chunk['data'], 20, 2)); // Frame delay fraction numerator
 472                                         $fcTL['delay_den']       = getid3_lib::BigEndian2Int(substr($chunk['data'], 22, 2)); // Frame delay fraction numerator
 473                                         $fcTL['dispose_op']      = getid3_lib::BigEndian2Int(substr($chunk['data'], 23, 1)); // Type of frame area disposal to be done after rendering this frame
 474                                         $fcTL['blend_op']        = getid3_lib::BigEndian2Int(substr($chunk['data'], 23, 1)); // Type of frame area rendering for this frame
 475                                         if ($fcTL['delay_den']) {
 476                                                 $fcTL['delay'] = $fcTL['delay_num'] / $fcTL['delay_den'];
 477                                         }
 478                                         $thisfile_png['animation']['fcTL'][$fcTL['sequence_number']] = $fcTL;
 479
 480                                         unset($chunk['data']);
 481                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 482                                         break;
 483
 484                                 case 'fdAT': // Frame Data chunk
 485                                         // https://wiki.mozilla.org/APNG_Specification#.60fcTL.60:_The_Frame_Control_Chunk
 486                                         // "The `fdAT` chunk has the same purpose as an `IDAT` chunk. It has the same structure as an `IDAT` chunk, except preceded by a sequence number."
 487                                         unset($chunk['data']);
 488                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 489                                         break;
 490
 491                                 default:
 492                                         //unset($chunk['data']);
 493                                         $thisfile_png_chunk_type_text['header'] = $chunk;
 494                                         $this->warning('Unhandled chunk type: '.$chunk['type_text']);
 495                                         break;
 496                         }
 497                 }
 498                 if (!empty($thisfile_png['animation']['num_frames']) && !empty($thisfile_png['animation']['fcTL'])) {
 499                         $info['video']['dataformat'] = 'apng';
 500                         $info['playtime_seconds'] = 0;
 501                         foreach ($thisfile_png['animation']['fcTL'] as $seqno => $fcTL) {
 502                                 $info['playtime_seconds'] += $fcTL['delay'];
 503                         }
 504                 }
 505                 return true;
 506         }
 507
 508         /**
 509          * @param int $sRGB
 510          *
 511          * @return string
 512          */
 513         public function PNGsRGBintentLookup($sRGB) {
 514                 static $PNGsRGBintentLookup = array(
 515                         0 => 'Perceptual',
 516                         1 => 'Relative colorimetric',
 517                         2 => 'Saturation',
 518                         3 => 'Absolute colorimetric'
 519                 );
 520                 return (isset($PNGsRGBintentLookup[$sRGB]) ? $PNGsRGBintentLookup[$sRGB] : 'invalid');
 521         }
 522
 523         /**
 524          * @param int $compressionmethod
 525          *
 526          * @return string
 527          */
 528         public function PNGcompressionMethodLookup($compressionmethod) {
 529                 static $PNGcompressionMethodLookup = array(
 530                         0 => 'deflate/inflate'
 531                 );
 532                 return (isset($PNGcompressionMethodLookup[$compressionmethod]) ? $PNGcompressionMethodLookup[$compressionmethod] : 'invalid');
 533         }
 534
 535         /**
 536          * @param int $unitid
 537          *
 538          * @return string
 539          */
 540         public function PNGpHYsUnitLookup($unitid) {
 541                 static $PNGpHYsUnitLookup = array(
 542                         0 => 'unknown',
 543                         1 => 'meter'
 544                 );
 545                 return (isset($PNGpHYsUnitLookup[$unitid]) ? $PNGpHYsUnitLookup[$unitid] : 'invalid');
 546         }
 547
 548         /**
 549          * @param int $unitid
 550          *
 551          * @return string
 552          */
 553         public function PNGoFFsUnitLookup($unitid) {
 554                 static $PNGoFFsUnitLookup = array(
 555                         0 => 'pixel',
 556                         1 => 'micrometer'
 557                 );
 558                 return (isset($PNGoFFsUnitLookup[$unitid]) ? $PNGoFFsUnitLookup[$unitid] : 'invalid');
 559         }
 560
 561         /**
 562          * @param int $equationtype
 563          *
 564          * @return string
 565          */
 566         public function PNGpCALequationTypeLookup($equationtype) {
 567                 static $PNGpCALequationTypeLookup = array(
 568                         0 => 'Linear mapping',
 569                         1 => 'Base-e exponential mapping',
 570                         2 => 'Arbitrary-base exponential mapping',
 571                         3 => 'Hyperbolic mapping'
 572                 );
 573                 return (isset($PNGpCALequationTypeLookup[$equationtype]) ? $PNGpCALequationTypeLookup[$equationtype] : 'invalid');
 574         }
 575
 576         /**
 577          * @param int $unitid
 578          *
 579          * @return string
 580          */
 581         public function PNGsCALUnitLookup($unitid) {
 582                 static $PNGsCALUnitLookup = array(
 583                         0 => 'meter',
 584                         1 => 'radian'
 585                 );
 586                 return (isset($PNGsCALUnitLookup[$unitid]) ? $PNGsCALUnitLookup[$unitid] : 'invalid');
 587         }
 588
 589         /**
 590          * @param int $color_type
 591          * @param int $bit_depth
 592          *
 593          * @return int|false
 594          */
 595         public function IHDRcalculateBitsPerSample($color_type, $bit_depth) {
 596                 switch ($color_type) {
 597                         case 0: // Each pixel is a grayscale sample.
 598                                 return $bit_depth;
 599
 600                         case 2: // Each pixel is an R,G,B triple
 601                                 return 3 * $bit_depth;
 602
 603                         case 3: // Each pixel is a palette index; a PLTE chunk must appear.
 604                                 return $bit_depth;
 605
 606                         case 4: // Each pixel is a grayscale sample, followed by an alpha sample.
 607                                 return 2 * $bit_depth;
 608
 609                         case 6: // Each pixel is an R,G,B triple, followed by an alpha sample.
 610                                 return 4 * $bit_depth;
 611                 }
 612                 return false;
 613         }
 614
 615 }