MediaWiki REL1_34
DjVuImage.php
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1<?php
28
38class DjVuImage {
39
43 const DJVUTXT_MEMORY_LIMIT = 300000;
44
46 private $mFilename;
47
51 function __construct( $filename ) {
52 $this->mFilename = $filename;
53 }
54
59 public function isValid() {
60 $info = $this->getInfo();
61
62 return $info !== false;
63 }
64
69 public function getImageSize() {
70 $data = $this->getInfo();
71
72 if ( $data !== false ) {
73 $width = $data['width'];
74 $height = $data['height'];
75
76 return [ $width, $height, 'DjVu',
77 "width=\"$width\" height=\"$height\"" ];
78 }
79
80 return false;
81 }
82
83 // ---------
84
88 function dump() {
89 $file = fopen( $this->mFilename, 'rb' );
90 $header = fread( $file, 12 );
91 $arr = unpack( 'a4magic/a4chunk/NchunkLength', $header );
92 $chunk = $arr['chunk'];
93 $chunkLength = $arr['chunkLength'];
94 echo "$chunk $chunkLength\n";
95 $this->dumpForm( $file, $chunkLength, 1 );
96 fclose( $file );
97 }
98
99 private function dumpForm( $file, $length, $indent ) {
100 $start = ftell( $file );
101 $secondary = fread( $file, 4 );
102 echo str_repeat( ' ', $indent * 4 ) . "($secondary)\n";
103 while ( ftell( $file ) - $start < $length ) {
104 $chunkHeader = fread( $file, 8 );
105 if ( $chunkHeader == '' ) {
106 break;
107 }
108 $arr = unpack( 'a4chunk/NchunkLength', $chunkHeader );
109 $chunk = $arr['chunk'];
110 $chunkLength = $arr['chunkLength'];
111 echo str_repeat( ' ', $indent * 4 ) . "$chunk $chunkLength\n";
112
113 if ( $chunk == 'FORM' ) {
114 $this->dumpForm( $file, $chunkLength, $indent + 1 );
115 } else {
116 fseek( $file, $chunkLength, SEEK_CUR );
117 if ( $chunkLength & 1 ) {
118 // Padding byte between chunks
119 fseek( $file, 1, SEEK_CUR );
120 }
121 }
122 }
123 }
124
125 function getInfo() {
126 Wikimedia\suppressWarnings();
127 $file = fopen( $this->mFilename, 'rb' );
128 Wikimedia\restoreWarnings();
129 if ( $file === false ) {
130 wfDebug( __METHOD__ . ": missing or failed file read\n" );
131
132 return false;
133 }
134
135 $header = fread( $file, 16 );
136 $info = false;
137
138 if ( strlen( $header ) < 16 ) {
139 wfDebug( __METHOD__ . ": too short file header\n" );
140 } else {
141 $arr = unpack( 'a4magic/a4form/NformLength/a4subtype', $header );
142
143 $subtype = $arr['subtype'];
144 if ( $arr['magic'] != 'AT&T' ) {
145 wfDebug( __METHOD__ . ": not a DjVu file\n" );
146 } elseif ( $subtype == 'DJVU' ) {
147 // Single-page document
148 $info = $this->getPageInfo( $file );
149 } elseif ( $subtype == 'DJVM' ) {
150 // Multi-page document
151 $info = $this->getMultiPageInfo( $file, $arr['formLength'] );
152 } else {
153 wfDebug( __METHOD__ . ": unrecognized DJVU file type '{$arr['subtype']}'\n" );
154 }
155 }
156 fclose( $file );
157
158 return $info;
159 }
160
161 private function readChunk( $file ) {
162 $header = fread( $file, 8 );
163 if ( strlen( $header ) < 8 ) {
164 return [ false, 0 ];
165 } else {
166 $arr = unpack( 'a4chunk/Nlength', $header );
167
168 return [ $arr['chunk'], $arr['length'] ];
169 }
170 }
171
172 private function skipChunk( $file, $chunkLength ) {
173 fseek( $file, $chunkLength, SEEK_CUR );
174
175 if ( ( $chunkLength & 1 ) && !feof( $file ) ) {
176 // padding byte
177 fseek( $file, 1, SEEK_CUR );
178 }
179 }
180
181 private function getMultiPageInfo( $file, $formLength ) {
182 // For now, we'll just look for the first page in the file
183 // and report its information, hoping others are the same size.
184 $start = ftell( $file );
185 do {
186 list( $chunk, $length ) = $this->readChunk( $file );
187 if ( !$chunk ) {
188 break;
189 }
190
191 if ( $chunk == 'FORM' ) {
192 $subtype = fread( $file, 4 );
193 if ( $subtype == 'DJVU' ) {
194 wfDebug( __METHOD__ . ": found first subpage\n" );
195
196 return $this->getPageInfo( $file );
197 }
198 $this->skipChunk( $file, $length - 4 );
199 } else {
200 wfDebug( __METHOD__ . ": skipping '$chunk' chunk\n" );
201 $this->skipChunk( $file, $length );
202 }
203 } while ( $length != 0 && !feof( $file ) && ftell( $file ) - $start < $formLength );
204
205 wfDebug( __METHOD__ . ": multi-page DJVU file contained no pages\n" );
206
207 return false;
208 }
209
210 private function getPageInfo( $file ) {
211 list( $chunk, $length ) = $this->readChunk( $file );
212 if ( $chunk != 'INFO' ) {
213 wfDebug( __METHOD__ . ": expected INFO chunk, got '$chunk'\n" );
214
215 return false;
216 }
217
218 if ( $length < 9 ) {
219 wfDebug( __METHOD__ . ": INFO should be 9 or 10 bytes, found $length\n" );
220
221 return false;
222 }
223 $data = fread( $file, $length );
224 if ( strlen( $data ) < $length ) {
225 wfDebug( __METHOD__ . ": INFO chunk cut off\n" );
226
227 return false;
228 }
229
230 $arr = unpack(
231 'nwidth/' .
232 'nheight/' .
233 'Cminor/' .
234 'Cmajor/' .
235 'vresolution/' .
236 'Cgamma', $data );
237
238 # Newer files have rotation info in byte 10, but we don't use it yet.
239
240 return [
241 'width' => $arr['width'],
242 'height' => $arr['height'],
243 'version' => "{$arr['major']}.{$arr['minor']}",
244 'resolution' => $arr['resolution'],
245 'gamma' => $arr['gamma'] / 10.0 ];
246 }
247
252 function retrieveMetaData() {
254
255 if ( !$this->isValid() ) {
256 return false;
257 }
258
259 if ( isset( $wgDjvuDump ) ) {
260 # djvudump is faster as of version 3.5
261 # https://sourceforge.net/p/djvu/bugs/71/
262 $cmd = Shell::escape( $wgDjvuDump ) . ' ' . Shell::escape( $this->mFilename );
263 $dump = wfShellExec( $cmd );
264 $xml = $this->convertDumpToXML( $dump );
265 } elseif ( isset( $wgDjvuToXML ) ) {
266 $cmd = Shell::escape( $wgDjvuToXML ) . ' --without-anno --without-text ' .
267 Shell::escape( $this->mFilename );
268 $xml = wfShellExec( $cmd );
269 } else {
270 $xml = null;
271 }
272 # Text layer
273 if ( isset( $wgDjvuTxt ) ) {
274 $cmd = Shell::escape( $wgDjvuTxt ) . ' --detail=page ' . Shell::escape( $this->mFilename );
275 wfDebug( __METHOD__ . ": $cmd\n" );
276 $retval = '';
277 $txt = wfShellExec( $cmd, $retval, [], [ 'memory' => self::DJVUTXT_MEMORY_LIMIT ] );
278 if ( $retval == 0 ) {
279 # Strip some control characters
280 $txt = preg_replace( "/[\013\035\037]/", "", $txt );
281 $reg = <<<EOR
282 /\‍(page\s[\d-]*\s[\d-]*\s[\d-]*\s[\d-]*\s*"
283 ((?> # Text to match is composed of atoms of either:
284 \\\\. # - any escaped character
285 | # - any character different from " and \
286 [^"\\\\]+
287 )*?)
288 "\s*\‍)
289 | # Or page can be empty ; in this case, djvutxt dumps ()
290 \‍(\s*()\)/sx
291EOR;
292 $txt = preg_replace_callback( $reg, [ $this, 'pageTextCallback' ], $txt );
293 $txt = "<DjVuTxt>\n<HEAD></HEAD>\n<BODY>\n" . $txt . "</BODY>\n</DjVuTxt>\n";
294 $xml = preg_replace( "/<DjVuXML>/", "<mw-djvu><DjVuXML>", $xml, 1 ) .
295 $txt .
296 '</mw-djvu>';
297 }
298 }
299
300 return $xml;
301 }
302
304 # Get rid of invalid UTF-8, strip control characters
305 $val = htmlspecialchars( UtfNormal\Validator::cleanUp( stripcslashes( $matches[1] ) ) );
306 $val = str_replace( [ "\n", '�' ], [ '&#10;', '' ], $val );
307 return '<PAGE value="' . $val . '" />';
308 }
309
315 function convertDumpToXML( $dump ) {
316 if ( strval( $dump ) == '' ) {
317 return false;
318 }
319
320 $xml = <<<EOT
321<?xml version="1.0" ?>
322<!DOCTYPE DjVuXML PUBLIC "-//W3C//DTD DjVuXML 1.1//EN" "pubtext/DjVuXML-s.dtd">
323<DjVuXML>
324<HEAD></HEAD>
325<BODY>
326EOT;
327
328 $dump = str_replace( "\r", '', $dump );
329 $line = strtok( $dump, "\n" );
330 $m = false;
331 $good = false;
332 if ( preg_match( '/^( *)FORM:DJVU/', $line, $m ) ) {
333 # Single-page
334 if ( $this->parseFormDjvu( $line, $xml ) ) {
335 $good = true;
336 } else {
337 return false;
338 }
339 } elseif ( preg_match( '/^( *)FORM:DJVM/', $line, $m ) ) {
340 # Multi-page
341 $parentLevel = strlen( $m[1] );
342 # Find DIRM
343 $line = strtok( "\n" );
344 while ( $line !== false ) {
345 $childLevel = strspn( $line, ' ' );
346 if ( $childLevel <= $parentLevel ) {
347 # End of chunk
348 break;
349 }
350
351 if ( preg_match( '/^ *DIRM.*indirect/', $line ) ) {
352 wfDebug( "Indirect multi-page DjVu document, bad for server!\n" );
353
354 return false;
355 }
356 if ( preg_match( '/^ *FORM:DJVU/', $line ) ) {
357 # Found page
358 if ( $this->parseFormDjvu( $line, $xml ) ) {
359 $good = true;
360 } else {
361 return false;
362 }
363 }
364 $line = strtok( "\n" );
365 }
366 }
367 if ( !$good ) {
368 return false;
369 }
370
371 $xml .= "</BODY>\n</DjVuXML>\n";
372
373 return $xml;
374 }
375
376 function parseFormDjvu( $line, &$xml ) {
377 $parentLevel = strspn( $line, ' ' );
378 $line = strtok( "\n" );
379
380 # Find INFO
381 while ( $line !== false ) {
382 $childLevel = strspn( $line, ' ' );
383 if ( $childLevel <= $parentLevel ) {
384 # End of chunk
385 break;
386 }
387
388 if ( preg_match(
389 '/^ *INFO *\[\d*\] *DjVu *(\d+)x(\d+), *\w*, *(\d+) *dpi, *gamma=([0-9.-]+)/',
390 $line,
391 $m
392 ) ) {
393 $xml .= Xml::tags(
394 'OBJECT',
395 [
396 # 'data' => '',
397 # 'type' => 'image/x.djvu',
398 'height' => $m[2],
399 'width' => $m[1],
400 # 'usemap' => '',
401 ],
402 "\n" .
403 Xml::element( 'PARAM', [ 'name' => 'DPI', 'value' => $m[3] ] ) . "\n" .
404 Xml::element( 'PARAM', [ 'name' => 'GAMMA', 'value' => $m[4] ] ) . "\n"
405 ) . "\n";
406
407 return true;
408 }
409 $line = strtok( "\n" );
410 }
411
412 # Not found
413 return false;
414 }
415}
$wgDjvuToXML
Path of the djvutoxml executable This works like djvudump except much, much slower as of version 3....
$wgDjvuTxt
Path of the djvutxt DJVU text extraction utility Enable this and $wgDjvuDump to enable text layer ext...
$wgDjvuDump
Path of the djvudump executable Enable this and $wgDjvuRenderer to enable djvu rendering example: $wg...
wfDebug( $text, $dest='all', array $context=[])
Sends a line to the debug log if enabled or, optionally, to a comment in output.
wfShellExec( $cmd, &$retval=null, $environ=[], $limits=[], $options=[])
Execute a shell command, with time and memory limits mirrored from the PHP configuration if supported...
$line
Definition cdb.php:59
Support for detecting/validating DjVu image files and getting some basic file metadata (resolution et...
Definition DjVuImage.php:38
getPageInfo( $file)
convertDumpToXML( $dump)
Hack to temporarily work around djvutoxml bug.
string $mFilename
Definition DjVuImage.php:46
parseFormDjvu( $line, &$xml)
retrieveMetaData()
Return an XML string describing the DjVu image.
const DJVUTXT_MEMORY_LIMIT
Memory limit for the DjVu description software.
Definition DjVuImage.php:43
skipChunk( $file, $chunkLength)
dumpForm( $file, $length, $indent)
Definition DjVuImage.php:99
pageTextCallback( $matches)
dump()
For debugging; dump the IFF chunk structure.
Definition DjVuImage.php:88
isValid()
Check if the given file is indeed a valid DjVu image file.
Definition DjVuImage.php:59
getMultiPageInfo( $file, $formLength)
readChunk( $file)
getImageSize()
Return data in the style of getimagesize()
Definition DjVuImage.php:69
__construct( $filename)
Definition DjVuImage.php:51
Executes shell commands.
Definition Shell.php:44
if(PHP_SAPI !='cli-server') if(!isset( $_SERVER['SCRIPT_FILENAME'])) $file
Item class for a filearchive table row.
Definition router.php:42
$header