ILIAS  release_5-1 Revision 5.0.0-5477-g43f3e3fab5f
module.graphic.png.php
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1<?php
4// available at http://getid3.sourceforge.net //
5// or http://www.getid3.org //
7// See readme.txt for more details //
9// //
10// module.graphic.png.php //
11// module for analyzing PNG Image files //
12// dependencies: NONE //
13// ///
15
16
17class getid3_png
18{
19
20 function getid3_png(&$fd, &$ThisFileInfo) {
21
22 // shortcut
23 $ThisFileInfo['png'] = array();
24 $thisfile_png = &$ThisFileInfo['png'];
25
26 $ThisFileInfo['fileformat'] = 'png';
27 $ThisFileInfo['video']['dataformat'] = 'png';
28 $ThisFileInfo['video']['lossless'] = false;
29
30 fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET);
31 $PNGfiledata = fread($fd, GETID3_FREAD_BUFFER_SIZE);
32 $offset = 0;
33
34 $PNGidentifier = substr($PNGfiledata, $offset, 8); // $89 $50 $4E $47 $0D $0A $1A $0A
35 $offset += 8;
36
37 if ($PNGidentifier != "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A") {
38 $ThisFileInfo['error'][] = 'First 8 bytes of file ('.getid3_lib::PrintHexBytes($PNGidentifier).') did not match expected PNG identifier';
39 unset($ThisFileInfo['fileformat']);
40 return false;
41 }
42
43 while (((ftell($fd) - (strlen($PNGfiledata) - $offset)) < $ThisFileInfo['filesize'])) {
44 $chunk['data_length'] = getid3_lib::BigEndian2Int(substr($PNGfiledata, $offset, 4));
45 $offset += 4;
46 while (((strlen($PNGfiledata) - $offset) < ($chunk['data_length'] + 4)) && (ftell($fd) < $ThisFileInfo['filesize'])) {
47 $PNGfiledata .= fread($fd, GETID3_FREAD_BUFFER_SIZE);
48 }
49 $chunk['type_text'] = substr($PNGfiledata, $offset, 4);
50 $offset += 4;
51 $chunk['type_raw'] = getid3_lib::BigEndian2Int($chunk['type_text']);
52 $chunk['data'] = substr($PNGfiledata, $offset, $chunk['data_length']);
53 $offset += $chunk['data_length'];
54 $chunk['crc'] = getid3_lib::BigEndian2Int(substr($PNGfiledata, $offset, 4));
55 $offset += 4;
56
57 $chunk['flags']['ancilliary'] = (bool) ($chunk['type_raw'] & 0x20000000);
58 $chunk['flags']['private'] = (bool) ($chunk['type_raw'] & 0x00200000);
59 $chunk['flags']['reserved'] = (bool) ($chunk['type_raw'] & 0x00002000);
60 $chunk['flags']['safe_to_copy'] = (bool) ($chunk['type_raw'] & 0x00000020);
61
62 // shortcut
63 $thisfile_png[$chunk['type_text']] = array();
64 $thisfile_png_chunk_type_text = &$thisfile_png[$chunk['type_text']];
65
66 switch ($chunk['type_text']) {
67
68 case 'IHDR': // Image Header
69 $thisfile_png_chunk_type_text['header'] = $chunk;
70 $thisfile_png_chunk_type_text['width'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 0, 4));
71 $thisfile_png_chunk_type_text['height'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 4, 4));
72 $thisfile_png_chunk_type_text['raw']['bit_depth'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 8, 1));
73 $thisfile_png_chunk_type_text['raw']['color_type'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 9, 1));
74 $thisfile_png_chunk_type_text['raw']['compression_method'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 10, 1));
75 $thisfile_png_chunk_type_text['raw']['filter_method'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 11, 1));
76 $thisfile_png_chunk_type_text['raw']['interlace_method'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 12, 1));
77
78 $thisfile_png_chunk_type_text['compression_method_text'] = $this->PNGcompressionMethodLookup($thisfile_png_chunk_type_text['raw']['compression_method']);
79 $thisfile_png_chunk_type_text['color_type']['palette'] = (bool) ($thisfile_png_chunk_type_text['raw']['color_type'] & 0x01);
80 $thisfile_png_chunk_type_text['color_type']['true_color'] = (bool) ($thisfile_png_chunk_type_text['raw']['color_type'] & 0x02);
81 $thisfile_png_chunk_type_text['color_type']['alpha'] = (bool) ($thisfile_png_chunk_type_text['raw']['color_type'] & 0x04);
82
83 $ThisFileInfo['video']['resolution_x'] = $thisfile_png_chunk_type_text['width'];
84 $ThisFileInfo['video']['resolution_y'] = $thisfile_png_chunk_type_text['height'];
85
86 $ThisFileInfo['video']['bits_per_sample'] = $this->IHDRcalculateBitsPerSample($thisfile_png_chunk_type_text['raw']['color_type'], $thisfile_png_chunk_type_text['raw']['bit_depth']);
87 break;
88
89
90 case 'PLTE': // Palette
91 $thisfile_png_chunk_type_text['header'] = $chunk;
92 $paletteoffset = 0;
93 for ($i = 0; $i <= 255; $i++) {
94 //$thisfile_png_chunk_type_text['red'][$i] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], $paletteoffset++, 1));
95 //$thisfile_png_chunk_type_text['green'][$i] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], $paletteoffset++, 1));
96 //$thisfile_png_chunk_type_text['blue'][$i] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], $paletteoffset++, 1));
97 $red = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], $paletteoffset++, 1));
98 $green = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], $paletteoffset++, 1));
99 $blue = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], $paletteoffset++, 1));
100 $thisfile_png_chunk_type_text[$i] = (($red << 16) | ($green << 8) | ($blue));
101 }
102 break;
103
104
105 case 'tRNS': // Transparency
106 $thisfile_png_chunk_type_text['header'] = $chunk;
107 switch ($thisfile_png['IHDR']['raw']['color_type']) {
108 case 0:
109 $thisfile_png_chunk_type_text['transparent_color_gray'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 0, 2));
110 break;
111
112 case 2:
113 $thisfile_png_chunk_type_text['transparent_color_red'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 0, 2));
114 $thisfile_png_chunk_type_text['transparent_color_green'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 2, 2));
115 $thisfile_png_chunk_type_text['transparent_color_blue'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 4, 2));
116 break;
117
118 case 3:
119 for ($i = 0; $i < strlen($thisfile_png_chunk_type_text['header']['data']); $i++) {
120 $thisfile_png_chunk_type_text['palette_opacity'][$i] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], $i, 1));
121 }
122 break;
123
124 case 4:
125 case 6:
126 $ThisFileInfo['error'][] = 'Invalid color_type in tRNS chunk: '.$thisfile_png['IHDR']['raw']['color_type'];
127
128 default:
129 $ThisFileInfo['warning'][] = 'Unhandled color_type in tRNS chunk: '.$thisfile_png['IHDR']['raw']['color_type'];
130 break;
131 }
132 break;
133
134
135 case 'gAMA': // Image Gamma
136 $thisfile_png_chunk_type_text['header'] = $chunk;
137 $thisfile_png_chunk_type_text['gamma'] = getid3_lib::BigEndian2Int($thisfile_png_chunk_type_text['header']['data']) / 100000;
138 break;
139
140
141 case 'cHRM': // Primary Chromaticities
142 $thisfile_png_chunk_type_text['header'] = $chunk;
143 $thisfile_png_chunk_type_text['white_x'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 0, 4)) / 100000;
144 $thisfile_png_chunk_type_text['white_y'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 4, 4)) / 100000;
145 $thisfile_png_chunk_type_text['red_y'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 8, 4)) / 100000;
146 $thisfile_png_chunk_type_text['red_y'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 12, 4)) / 100000;
147 $thisfile_png_chunk_type_text['green_y'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 16, 4)) / 100000;
148 $thisfile_png_chunk_type_text['green_y'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 20, 4)) / 100000;
149 $thisfile_png_chunk_type_text['blue_y'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 24, 4)) / 100000;
150 $thisfile_png_chunk_type_text['blue_y'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 28, 4)) / 100000;
151 break;
152
153
154 case 'sRGB': // Standard RGB Color Space
155 $thisfile_png_chunk_type_text['header'] = $chunk;
156 $thisfile_png_chunk_type_text['reindering_intent'] = getid3_lib::BigEndian2Int($thisfile_png_chunk_type_text['header']['data']);
157 $thisfile_png_chunk_type_text['reindering_intent_text'] = $this->PNGsRGBintentLookup($thisfile_png_chunk_type_text['reindering_intent']);
158 break;
159
160
161 case 'iCCP': // Embedded ICC Profile
162 $thisfile_png_chunk_type_text['header'] = $chunk;
163 list($profilename, $compressiondata) = explode("\x00", $thisfile_png_chunk_type_text['header']['data'], 2);
164 $thisfile_png_chunk_type_text['profile_name'] = $profilename;
165 $thisfile_png_chunk_type_text['compression_method'] = getid3_lib::BigEndian2Int(substr($compressiondata, 0, 1));
166 $thisfile_png_chunk_type_text['compression_profile'] = substr($compressiondata, 1);
167
168 $thisfile_png_chunk_type_text['compression_method_text'] = $this->PNGcompressionMethodLookup($thisfile_png_chunk_type_text['compression_method']);
169 break;
170
171
172 case 'tEXt': // Textual Data
173 $thisfile_png_chunk_type_text['header'] = $chunk;
174 list($keyword, $text) = explode("\x00", $thisfile_png_chunk_type_text['header']['data'], 2);
175 $thisfile_png_chunk_type_text['keyword'] = $keyword;
176 $thisfile_png_chunk_type_text['text'] = $text;
177
178 $thisfile_png['comments'][$thisfile_png_chunk_type_text['keyword']][] = $thisfile_png_chunk_type_text['text'];
179 break;
180
181
182 case 'zTXt': // Compressed Textual Data
183 $thisfile_png_chunk_type_text['header'] = $chunk;
184 list($keyword, $otherdata) = explode("\x00", $thisfile_png_chunk_type_text['header']['data'], 2);
185 $thisfile_png_chunk_type_text['keyword'] = $keyword;
186 $thisfile_png_chunk_type_text['compression_method'] = getid3_lib::BigEndian2Int(substr($otherdata, 0, 1));
187 $thisfile_png_chunk_type_text['compressed_text'] = substr($otherdata, 1);
188 $thisfile_png_chunk_type_text['compression_method_text'] = $this->PNGcompressionMethodLookup($thisfile_png_chunk_type_text['compression_method']);
189 switch ($thisfile_png_chunk_type_text['compression_method']) {
190 case 0:
191 $thisfile_png_chunk_type_text['text'] = gzuncompress($thisfile_png_chunk_type_text['compressed_text']);
192 break;
193
194 default:
195 // unknown compression method
196 break;
197 }
198
199 if (isset($thisfile_png_chunk_type_text['text'])) {
200 $thisfile_png['comments'][$thisfile_png_chunk_type_text['keyword']][] = $thisfile_png_chunk_type_text['text'];
201 }
202 break;
203
204
205 case 'iTXt': // International Textual Data
206 $thisfile_png_chunk_type_text['header'] = $chunk;
207 list($keyword, $otherdata) = explode("\x00", $thisfile_png_chunk_type_text['header']['data'], 2);
208 $thisfile_png_chunk_type_text['keyword'] = $keyword;
209 $thisfile_png_chunk_type_text['compression'] = (bool) getid3_lib::BigEndian2Int(substr($otherdata, 0, 1));
210 $thisfile_png_chunk_type_text['compression_method'] = getid3_lib::BigEndian2Int(substr($otherdata, 1, 1));
211 $thisfile_png_chunk_type_text['compression_method_text'] = $this->PNGcompressionMethodLookup($thisfile_png_chunk_type_text['compression_method']);
212 list($languagetag, $translatedkeyword, $text) = explode("\x00", substr($otherdata, 2), 3);
213 $thisfile_png_chunk_type_text['language_tag'] = $languagetag;
214 $thisfile_png_chunk_type_text['translated_keyword'] = $translatedkeyword;
215
216 if ($thisfile_png_chunk_type_text['compression']) {
217
218 switch ($thisfile_png_chunk_type_text['compression_method']) {
219 case 0:
220 $thisfile_png_chunk_type_text['text'] = gzuncompress($text);
221 break;
222
223 default:
224 // unknown compression method
225 break;
226 }
227
228 } else {
229
230 $thisfile_png_chunk_type_text['text'] = $text;
231
232 }
233
234 if (isset($thisfile_png_chunk_type_text['text'])) {
235 $thisfile_png['comments'][$thisfile_png_chunk_type_text['keyword']][] = $thisfile_png_chunk_type_text['text'];
236 }
237 break;
238
239
240 case 'bKGD': // Background Color
241 $thisfile_png_chunk_type_text['header'] = $chunk;
242 switch ($thisfile_png['IHDR']['raw']['color_type']) {
243 case 0:
244 case 4:
245 $thisfile_png_chunk_type_text['background_gray'] = getid3_lib::BigEndian2Int($thisfile_png_chunk_type_text['header']['data']);
246 break;
247
248 case 2:
249 case 6:
250 $thisfile_png_chunk_type_text['background_red'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 0 * $thisfile_png['IHDR']['raw']['bit_depth'], $thisfile_png['IHDR']['raw']['bit_depth']));
251 $thisfile_png_chunk_type_text['background_green'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 1 * $thisfile_png['IHDR']['raw']['bit_depth'], $thisfile_png['IHDR']['raw']['bit_depth']));
252 $thisfile_png_chunk_type_text['background_blue'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 2 * $thisfile_png['IHDR']['raw']['bit_depth'], $thisfile_png['IHDR']['raw']['bit_depth']));
253 break;
254
255 case 3:
256 $thisfile_png_chunk_type_text['background_index'] = getid3_lib::BigEndian2Int($thisfile_png_chunk_type_text['header']['data']);
257 break;
258
259 default:
260 break;
261 }
262 break;
263
264
265 case 'pHYs': // Physical Pixel Dimensions
266 $thisfile_png_chunk_type_text['header'] = $chunk;
267 $thisfile_png_chunk_type_text['pixels_per_unit_x'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 0, 4));
268 $thisfile_png_chunk_type_text['pixels_per_unit_y'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 4, 4));
269 $thisfile_png_chunk_type_text['unit_specifier'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 8, 1));
270 $thisfile_png_chunk_type_text['unit'] = $this->PNGpHYsUnitLookup($thisfile_png_chunk_type_text['unit_specifier']);
271 break;
272
273
274 case 'sBIT': // Significant Bits
275 $thisfile_png_chunk_type_text['header'] = $chunk;
276 switch ($thisfile_png['IHDR']['raw']['color_type']) {
277 case 0:
278 $thisfile_png_chunk_type_text['significant_bits_gray'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 0, 1));
279 break;
280
281 case 2:
282 case 3:
283 $thisfile_png_chunk_type_text['significant_bits_red'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 0, 1));
284 $thisfile_png_chunk_type_text['significant_bits_green'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 1, 1));
285 $thisfile_png_chunk_type_text['significant_bits_blue'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 2, 1));
286 break;
287
288 case 4:
289 $thisfile_png_chunk_type_text['significant_bits_gray'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 0, 1));
290 $thisfile_png_chunk_type_text['significant_bits_alpha'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 1, 1));
291 break;
292
293 case 6:
294 $thisfile_png_chunk_type_text['significant_bits_red'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 0, 1));
295 $thisfile_png_chunk_type_text['significant_bits_green'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 1, 1));
296 $thisfile_png_chunk_type_text['significant_bits_blue'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 2, 1));
297 $thisfile_png_chunk_type_text['significant_bits_alpha'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 3, 1));
298 break;
299
300 default:
301 break;
302 }
303 break;
304
305
306 case 'sPLT': // Suggested Palette
307 $thisfile_png_chunk_type_text['header'] = $chunk;
308 list($palettename, $otherdata) = explode("\x00", $thisfile_png_chunk_type_text['header']['data'], 2);
309 $thisfile_png_chunk_type_text['palette_name'] = $palettename;
310 $sPLToffset = 0;
311 $thisfile_png_chunk_type_text['sample_depth_bits'] = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, 1));
312 $sPLToffset += 1;
313 $thisfile_png_chunk_type_text['sample_depth_bytes'] = $thisfile_png_chunk_type_text['sample_depth_bits'] / 8;
314 $paletteCounter = 0;
315 while ($sPLToffset < strlen($otherdata)) {
316 $thisfile_png_chunk_type_text['red'][$paletteCounter] = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, $thisfile_png_chunk_type_text['sample_depth_bytes']));
317 $sPLToffset += $thisfile_png_chunk_type_text['sample_depth_bytes'];
318 $thisfile_png_chunk_type_text['green'][$paletteCounter] = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, $thisfile_png_chunk_type_text['sample_depth_bytes']));
319 $sPLToffset += $thisfile_png_chunk_type_text['sample_depth_bytes'];
320 $thisfile_png_chunk_type_text['blue'][$paletteCounter] = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, $thisfile_png_chunk_type_text['sample_depth_bytes']));
321 $sPLToffset += $thisfile_png_chunk_type_text['sample_depth_bytes'];
322 $thisfile_png_chunk_type_text['alpha'][$paletteCounter] = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, $thisfile_png_chunk_type_text['sample_depth_bytes']));
323 $sPLToffset += $thisfile_png_chunk_type_text['sample_depth_bytes'];
324 $thisfile_png_chunk_type_text['frequency'][$paletteCounter] = getid3_lib::BigEndian2Int(substr($otherdata, $sPLToffset, 2));
325 $sPLToffset += 2;
326 $paletteCounter++;
327 }
328 break;
329
330
331 case 'hIST': // Palette Histogram
332 $thisfile_png_chunk_type_text['header'] = $chunk;
333 $hISTcounter = 0;
334 while ($hISTcounter < strlen($thisfile_png_chunk_type_text['header']['data'])) {
335 $thisfile_png_chunk_type_text[$hISTcounter] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], $hISTcounter / 2, 2));
336 $hISTcounter += 2;
337 }
338 break;
339
340
341 case 'tIME': // Image Last-Modification Time
342 $thisfile_png_chunk_type_text['header'] = $chunk;
343 $thisfile_png_chunk_type_text['year'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 0, 2));
344 $thisfile_png_chunk_type_text['month'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 2, 1));
345 $thisfile_png_chunk_type_text['day'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 3, 1));
346 $thisfile_png_chunk_type_text['hour'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 4, 1));
347 $thisfile_png_chunk_type_text['minute'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 5, 1));
348 $thisfile_png_chunk_type_text['second'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 6, 1));
349 $thisfile_png_chunk_type_text['unix'] = gmmktime($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']);
350 break;
351
352
353 case 'oFFs': // Image Offset
354 $thisfile_png_chunk_type_text['header'] = $chunk;
355 $thisfile_png_chunk_type_text['position_x'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 0, 4), false, true);
356 $thisfile_png_chunk_type_text['position_y'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 4, 4), false, true);
357 $thisfile_png_chunk_type_text['unit_specifier'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 8, 1));
358 $thisfile_png_chunk_type_text['unit'] = $this->PNGoFFsUnitLookup($thisfile_png_chunk_type_text['unit_specifier']);
359 break;
360
361
362 case 'pCAL': // Calibration Of Pixel Values
363 $thisfile_png_chunk_type_text['header'] = $chunk;
364 list($calibrationname, $otherdata) = explode("\x00", $thisfile_png_chunk_type_text['header']['data'], 2);
365 $thisfile_png_chunk_type_text['calibration_name'] = $calibrationname;
366 $pCALoffset = 0;
367 $thisfile_png_chunk_type_text['original_zero'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], $pCALoffset, 4), false, true);
368 $pCALoffset += 4;
369 $thisfile_png_chunk_type_text['original_max'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], $pCALoffset, 4), false, true);
370 $pCALoffset += 4;
371 $thisfile_png_chunk_type_text['equation_type'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], $pCALoffset, 1));
372 $pCALoffset += 1;
373 $thisfile_png_chunk_type_text['equation_type_text'] = $this->PNGpCALequationTypeLookup($thisfile_png_chunk_type_text['equation_type']);
374 $thisfile_png_chunk_type_text['parameter_count'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], $pCALoffset, 1));
375 $pCALoffset += 1;
376 $thisfile_png_chunk_type_text['parameters'] = explode("\x00", substr($thisfile_png_chunk_type_text['header']['data'], $pCALoffset));
377 break;
378
379
380 case 'sCAL': // Physical Scale Of Image Subject
381 $thisfile_png_chunk_type_text['header'] = $chunk;
382 $thisfile_png_chunk_type_text['unit_specifier'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 0, 1));
383 $thisfile_png_chunk_type_text['unit'] = $this->PNGsCALUnitLookup($thisfile_png_chunk_type_text['unit_specifier']);
384 list($pixelwidth, $pixelheight) = explode("\x00", substr($thisfile_png_chunk_type_text['header']['data'], 1));
385 $thisfile_png_chunk_type_text['pixel_width'] = $pixelwidth;
386 $thisfile_png_chunk_type_text['pixel_height'] = $pixelheight;
387 break;
388
389
390 case 'gIFg': // GIF Graphic Control Extension
391 $gIFgCounter = 0;
392 if (isset($thisfile_png_chunk_type_text) && is_array($thisfile_png_chunk_type_text)) {
393 $gIFgCounter = count($thisfile_png_chunk_type_text);
394 }
395 $thisfile_png_chunk_type_text[$gIFgCounter]['header'] = $chunk;
396 $thisfile_png_chunk_type_text[$gIFgCounter]['disposal_method'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 0, 1));
397 $thisfile_png_chunk_type_text[$gIFgCounter]['user_input_flag'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 1, 1));
398 $thisfile_png_chunk_type_text[$gIFgCounter]['delay_time'] = getid3_lib::BigEndian2Int(substr($thisfile_png_chunk_type_text['header']['data'], 2, 2));
399 break;
400
401
402 case 'gIFx': // GIF Application Extension
403 $gIFxCounter = 0;
404 if (isset($thisfile_png_chunk_type_text) && is_array($thisfile_png_chunk_type_text)) {
405 $gIFxCounter = count($thisfile_png_chunk_type_text);
406 }
407 $thisfile_png_chunk_type_text[$gIFxCounter]['header'] = $chunk;
408 $thisfile_png_chunk_type_text[$gIFxCounter]['application_identifier'] = substr($thisfile_png_chunk_type_text['header']['data'], 0, 8);
409 $thisfile_png_chunk_type_text[$gIFxCounter]['authentication_code'] = substr($thisfile_png_chunk_type_text['header']['data'], 8, 3);
410 $thisfile_png_chunk_type_text[$gIFxCounter]['application_data'] = substr($thisfile_png_chunk_type_text['header']['data'], 11);
411 break;
412
413
414 case 'IDAT': // Image Data
415 $idatinformationfieldindex = 0;
416 if (isset($thisfile_png['IDAT']) && is_array($thisfile_png['IDAT'])) {
417 $idatinformationfieldindex = count($thisfile_png['IDAT']);
418 }
419 unset($chunk['data']);
420 $thisfile_png_chunk_type_text[$idatinformationfieldindex]['header'] = $chunk;
421 break;
422
423
424 case 'IEND': // Image Trailer
425 $thisfile_png_chunk_type_text['header'] = $chunk;
426 break;
427
428
429 default:
430 //unset($chunk['data']);
431 $thisfile_png_chunk_type_text['header'] = $chunk;
432 $ThisFileInfo['warning'][] = 'Unhandled chunk type: '.$chunk['type_text'];
433 break;
434 }
435 }
436
437 return true;
438 }
439
440 function PNGsRGBintentLookup($sRGB) {
441 static $PNGsRGBintentLookup = array(
442 0 => 'Perceptual',
443 1 => 'Relative colorimetric',
444 2 => 'Saturation',
445 3 => 'Absolute colorimetric'
446 );
447 return (isset($PNGsRGBintentLookup[$sRGB]) ? $PNGsRGBintentLookup[$sRGB] : 'invalid');
448 }
449
450 function PNGcompressionMethodLookup($compressionmethod) {
451 static $PNGcompressionMethodLookup = array(
452 0 => 'deflate/inflate'
453 );
454 return (isset($PNGcompressionMethodLookup[$compressionmethod]) ? $PNGcompressionMethodLookup[$compressionmethod] : 'invalid');
455 }
456
457 function PNGpHYsUnitLookup($unitid) {
458 static $PNGpHYsUnitLookup = array(
459 0 => 'unknown',
460 1 => 'meter'
461 );
462 return (isset($PNGpHYsUnitLookup[$unitid]) ? $PNGpHYsUnitLookup[$unitid] : 'invalid');
463 }
464
465 function PNGoFFsUnitLookup($unitid) {
466 static $PNGoFFsUnitLookup = array(
467 0 => 'pixel',
468 1 => 'micrometer'
469 );
470 return (isset($PNGoFFsUnitLookup[$unitid]) ? $PNGoFFsUnitLookup[$unitid] : 'invalid');
471 }
472
473 function PNGpCALequationTypeLookup($equationtype) {
474 static $PNGpCALequationTypeLookup = array(
475 0 => 'Linear mapping',
476 1 => 'Base-e exponential mapping',
477 2 => 'Arbitrary-base exponential mapping',
478 3 => 'Hyperbolic mapping'
479 );
480 return (isset($PNGpCALequationTypeLookup[$equationtype]) ? $PNGpCALequationTypeLookup[$equationtype] : 'invalid');
481 }
482
483 function PNGsCALUnitLookup($unitid) {
484 static $PNGsCALUnitLookup = array(
485 0 => 'meter',
486 1 => 'radian'
487 );
488 return (isset($PNGsCALUnitLookup[$unitid]) ? $PNGsCALUnitLookup[$unitid] : 'invalid');
489 }
490
491 function IHDRcalculateBitsPerSample($color_type, $bit_depth) {
492 switch ($color_type) {
493 case 0: // Each pixel is a grayscale sample.
494 return $bit_depth;
495 break;
496
497 case 2: // Each pixel is an R,G,B triple
498 return 3 * $bit_depth;
499 break;
500
501 case 3: // Each pixel is a palette index; a PLTE chunk must appear.
502 return $bit_depth;
503 break;
504
505 case 4: // Each pixel is a grayscale sample, followed by an alpha sample.
506 return 2 * $bit_depth;
507 break;
508
509 case 6: // Each pixel is an R,G,B triple, followed by an alpha sample.
510 return 4 * $bit_depth;
511 break;
512 }
513 return false;
514 }
515
516}
517
518
519?>
getid3_handler\fseek
fseek($bytes, $whence=SEEK_SET)
Definition: getid3.php:1697
getid3_handler\ftell
ftell()
Definition: getid3.php:1678
getid3_handler\fread
fread($bytes)
Definition: getid3.php:1685
getid3_lib\BigEndian2Int
BigEndian2Int($byteword, $synchsafe=false, $signed=false)
Definition: getid3.lib.php:234
getid3_png
getID3() by James Heinrich info@getid3.org //
Definition: module.graphic.png.php:18
getid3_png\PNGsRGBintentLookup
PNGsRGBintentLookup($sRGB)
Definition: module.graphic.png.php:440
getid3_png\getid3_png
getid3_png(&$fd, &$ThisFileInfo)
Definition: module.graphic.png.php:20
getid3_png\IHDRcalculateBitsPerSample
IHDRcalculateBitsPerSample($color_type, $bit_depth)
Definition: module.graphic.png.php:491
getid3_png\PNGpHYsUnitLookup
PNGpHYsUnitLookup($unitid)
Definition: module.graphic.png.php:457
getid3_png\PNGpCALequationTypeLookup
PNGpCALequationTypeLookup($equationtype)
Definition: module.graphic.png.php:473
getid3_png\PNGcompressionMethodLookup
PNGcompressionMethodLookup($compressionmethod)
Definition: module.graphic.png.php:450
getid3_png\PNGoFFsUnitLookup
PNGoFFsUnitLookup($unitid)
Definition: module.graphic.png.php:465
getid3_png\PNGsCALUnitLookup
PNGsCALUnitLookup($unitid)
Definition: module.graphic.png.php:483
$text
$text
Definition: example_020.php:127
$red
$red
Definition: example_030.php:80
$green
$green
Definition: example_030.php:83
$blue
$blue
Definition: example_030.php:81
GETID3_FREAD_BUFFER_SIZE
const GETID3_FREAD_BUFFER_SIZE
Definition: getid3.php:14