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 17if (!defined('GETID3_INCLUDEPATH')) { // prevent path-exposing attacks that access modules directly on public webservers 18 exit; 19} 20 21class 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} 616
