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module.graphic.png.php @ 3544

Last change on this file since 3544 was 3544, checked in by vdigital, 15 years ago
Change: getid3 upgraded to -> 1.7.9
Property svn:eol-style set to `LF` Property svn:keywords set to `Author Date Id Revision`
File size: 25.0 KB

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1	<?php
2	/////////////////////////////////////////////////////////////////
3	/// getID3() by James Heinrich <info@getid3.org> //
4	// available at http://getid3.sourceforge.net //
5	// or http://www.getid3.org //
6	/////////////////////////////////////////////////////////////////
7	// See readme.txt for more details //
8	/////////////////////////////////////////////////////////////////
9	// //
10	// module.graphic.png.php //
11	// module for analyzing PNG Image files //
12	// dependencies: NONE //
13	// ///
14	/////////////////////////////////////////////////////////////////
15
16
17	class 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	$thisfile_png_chunk_type_text['width'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 4));
71	$thisfile_png_chunk_type_text['height'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 4));
72	$thisfile_png_chunk_type_text['raw']['bit_depth'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 8, 1));
73	$thisfile_png_chunk_type_text['raw']['color_type'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 9, 1));
74	$thisfile_png_chunk_type_text['raw']['compression_method'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 10, 1));
75	$thisfile_png_chunk_type_text['raw']['filter_method'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 11, 1));
76	$thisfile_png_chunk_type_text['raw']['interlace_method'] = getid3_lib::BigEndian2Int(substr($chunk['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'][$i] = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1));
95	//$thisfile_png_chunk_type_text['green'][$i] = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1));
96	//$thisfile_png_chunk_type_text['blue'][$i] = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1));
97	$red = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1));
98	$green = getid3_lib::BigEndian2Int(substr($chunk['data'], $paletteoffset++, 1));
99	$blue = getid3_lib::BigEndian2Int(substr($chunk['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	$thisfile_png_chunk_type_text['transparent_color_gray'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 2));
110	break;
111
112	case 2:
113	$thisfile_png_chunk_type_text['transparent_color_red'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 2));
114	$thisfile_png_chunk_type_text['transparent_color_green'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 2));
115	$thisfile_png_chunk_type_text['transparent_color_blue'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 2));
116	break;
117
118	case 3:
119	for ($i = 0; $i < strlen($chunk['data']); $i++) {
120	$thisfile_png_chunk_type_text['palette_opacity'][$i] = getid3_lib::BigEndian2Int(substr($chunk['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	$thisfile_png_chunk_type_text['gamma'] = getid3_lib::BigEndian2Int($chunk['data']) / 100000;
138	break;
139
140
141	case 'cHRM': // Primary Chromaticities
142	$thisfile_png_chunk_type_text['header'] = $chunk;
143	$thisfile_png_chunk_type_text['white_x'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 4)) / 100000;
144	$thisfile_png_chunk_type_text['white_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 4)) / 100000;
145	$thisfile_png_chunk_type_text['red_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 8, 4)) / 100000;
146	$thisfile_png_chunk_type_text['red_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 12, 4)) / 100000;
147	$thisfile_png_chunk_type_text['green_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 16, 4)) / 100000;
148	$thisfile_png_chunk_type_text['green_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 20, 4)) / 100000;
149	$thisfile_png_chunk_type_text['blue_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 24, 4)) / 100000;
150	$thisfile_png_chunk_type_text['blue_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 28, 4)) / 100000;
151	break;
152
153
154	case 'sRGB': // Standard RGB Color Space
155	$thisfile_png_chunk_type_text['header'] = $chunk;
156	$thisfile_png_chunk_type_text['reindering_intent'] = getid3_lib::BigEndian2Int($chunk['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", $chunk['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", $chunk['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", $chunk['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", $chunk['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	$thisfile_png_chunk_type_text['background_gray'] = getid3_lib::BigEndian2Int($chunk['data']);
246	break;
247
248	case 2:
249	case 6:
250	$thisfile_png_chunk_type_text['background_red'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0 * $thisfile_png['IHDR']['raw']['bit_depth'], $thisfile_png['IHDR']['raw']['bit_depth']));
251	$thisfile_png_chunk_type_text['background_green'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1 * $thisfile_png['IHDR']['raw']['bit_depth'], $thisfile_png['IHDR']['raw']['bit_depth']));
252	$thisfile_png_chunk_type_text['background_blue'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 2 * $thisfile_png['IHDR']['raw']['bit_depth'], $thisfile_png['IHDR']['raw']['bit_depth']));
253	break;
254
255	case 3:
256	$thisfile_png_chunk_type_text['background_index'] = getid3_lib::BigEndian2Int($chunk['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	$thisfile_png_chunk_type_text['pixels_per_unit_x'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 4));
268	$thisfile_png_chunk_type_text['pixels_per_unit_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 4));
269	$thisfile_png_chunk_type_text['unit_specifier'] = getid3_lib::BigEndian2Int(substr($chunk['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	$thisfile_png_chunk_type_text['significant_bits_gray'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1));
279	break;
280
281	case 2:
282	case 3:
283	$thisfile_png_chunk_type_text['significant_bits_red'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1));
284	$thisfile_png_chunk_type_text['significant_bits_green'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1, 1));
285	$thisfile_png_chunk_type_text['significant_bits_blue'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 1));
286	break;
287
288	case 4:
289	$thisfile_png_chunk_type_text['significant_bits_gray'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1));
290	$thisfile_png_chunk_type_text['significant_bits_alpha'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1, 1));
291	break;
292
293	case 6:
294	$thisfile_png_chunk_type_text['significant_bits_red'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1));
295	$thisfile_png_chunk_type_text['significant_bits_green'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1, 1));
296	$thisfile_png_chunk_type_text['significant_bits_blue'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 1));
297	$thisfile_png_chunk_type_text['significant_bits_alpha'] = getid3_lib::BigEndian2Int(substr($chunk['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", $chunk['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($chunk['data'])) {
335	$thisfile_png_chunk_type_text[$hISTcounter] = getid3_lib::BigEndian2Int(substr($chunk['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	$thisfile_png_chunk_type_text['year'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 2));
344	$thisfile_png_chunk_type_text['month'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 2, 1));
345	$thisfile_png_chunk_type_text['day'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 3, 1));
346	$thisfile_png_chunk_type_text['hour'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 1));
347	$thisfile_png_chunk_type_text['minute'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 5, 1));
348	$thisfile_png_chunk_type_text['second'] = getid3_lib::BigEndian2Int(substr($chunk['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	$thisfile_png_chunk_type_text['position_x'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 4), false, true);
356	$thisfile_png_chunk_type_text['position_y'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 4, 4), false, true);
357	$thisfile_png_chunk_type_text['unit_specifier'] = getid3_lib::BigEndian2Int(substr($chunk['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", $chunk['data'], 2);
365	$thisfile_png_chunk_type_text['calibration_name'] = $calibrationname;
366	$pCALoffset = 0;
367	$thisfile_png_chunk_type_text['original_zero'] = getid3_lib::BigEndian2Int(substr($chunk['data'], $pCALoffset, 4), false, true);
368	$pCALoffset += 4;
369	$thisfile_png_chunk_type_text['original_max'] = getid3_lib::BigEndian2Int(substr($chunk['data'], $pCALoffset, 4), false, true);
370	$pCALoffset += 4;
371	$thisfile_png_chunk_type_text['equation_type'] = getid3_lib::BigEndian2Int(substr($chunk['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	$thisfile_png_chunk_type_text['parameter_count'] = getid3_lib::BigEndian2Int(substr($chunk['data'], $pCALoffset, 1));
375	$pCALoffset += 1;
376	$thisfile_png_chunk_type_text['parameters'] = explode("\x00", substr($chunk['data'], $pCALoffset));
377	break;
378
379
380	case 'sCAL': // Physical Scale Of Image Subject
381	$thisfile_png_chunk_type_text['header'] = $chunk;
382	$thisfile_png_chunk_type_text['unit_specifier'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 0, 1));
383	$thisfile_png_chunk_type_text['unit'] = $this->PNGsCALUnitLookup($thisfile_png_chunk_type_text['unit_specifier']);
384	list($pixelwidth, $pixelheight) = explode("\x00", substr($chunk['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($chunk['data'], 0, 1));
397	$thisfile_png_chunk_type_text[$gIFgCounter]['user_input_flag'] = getid3_lib::BigEndian2Int(substr($chunk['data'], 1, 1));
398	$thisfile_png_chunk_type_text[$gIFgCounter]['delay_time'] = getid3_lib::BigEndian2Int(substr($chunk['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($chunk['data'], 0, 8);
409	$thisfile_png_chunk_type_text[$gIFxCounter]['authentication_code'] = substr($chunk['data'], 8, 3);
410	$thisfile_png_chunk_type_text[$gIFxCounter]['application_data'] = substr($chunk['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	?>

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source: extensions/charlies_content/getid3/getid3/module.graphic.png.php @ 3544

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