ILIAS  release_5-3 Revision v5.3.23-19-g915713cf615
module.graphic.png.php
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1 <?php
4 // available at http://getid3.sourceforge.net //
5 // or http://www.getid3.org //
6 // also https://github.com/JamesHeinrich/getID3 //
8 // See readme.txt for more details //
10 // //
11 // module.graphic.png.php //
12 // module for analyzing PNG Image files //
13 // dependencies: NONE //
14 // ///
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 }
$blue
$blue
Definition: example_030.php:81
getid3_handler\error
error($text)
Definition: getid3.php:1752
getid3_png\PNGcompressionMethodLookup
PNGcompressionMethodLookup($compressionmethod)
Definition: module.graphic.png.php:464
getid3_png\PNGpHYsUnitLookup
PNGpHYsUnitLookup($unitid)
Definition: module.graphic.png.php:471
getid3_handler\warning
warning($text)
Definition: getid3.php:1758
getid3_png\PNGoFFsUnitLookup
PNGoFFsUnitLookup($unitid)
Definition: module.graphic.png.php:479
getid3_png\$max_data_bytes
$max_data_bytes
Definition: module.graphic.png.php:20
getid3_png\PNGpCALequationTypeLookup
PNGpCALequationTypeLookup($equationtype)
Definition: module.graphic.png.php:487
$red
$red
Definition: example_030.php:80
getid3_handler
Definition: getid3.php:1616
$text
$text
Definition: errorreport.php:18
getid3_lib\PrintHexBytes
static PrintHexBytes($string, $hex=true, $spaces=true, $htmlencoding='UTF-8')
Definition: getid3.lib.php:18
getid3_handler\fread
fread($bytes)
Definition: getid3.php:1683
$green
$green
Definition: example_030.php:83
getid3_png\Analyze
Analyze()
Definition: module.graphic.png.php:22
array
Create styles array
The data for the language used.
Definition: 40duplicateStyle.php:19
getid3_png\PNGsRGBintentLookup
PNGsRGBintentLookup($sRGB)
Definition: module.graphic.png.php:454
getid3_png\PNGsCALUnitLookup
PNGsCALUnitLookup($unitid)
Definition: module.graphic.png.php:497
$i
$i
Definition: disco.tpl.php:19
getid3_png\IHDRcalculateBitsPerSample
IHDRcalculateBitsPerSample($color_type, $bit_depth)
Definition: module.graphic.png.php:505
getid3_handler\fseek
fseek($bytes, $whence=SEEK_SET)
Definition: getid3.php:1711
$info
$info
Definition: index.php:5
getid3_handler\ftell
ftell()
Definition: getid3.php:1676
getid3_lib\BigEndian2Int
static BigEndian2Int($byteword, $synchsafe=false, $signed=false)
Definition: getid3.lib.php:263
getid3_png
getID3() by James Heinrich info@getid3.org //
Definition: module.graphic.png.php:18