summaryrefslogtreecommitdiff
path: root/includes/MimeMagic.php
blob: 30861ba3ec27ab6726e79d1efee2b607e1fbf76c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
<?php
/** Module defining helper functions for detecting and dealing with mime types.
 *
 * @package MediaWiki
 */

 /** Defines a set of well known mime types
 * This is used as a fallback to mime.types files.
 * An extensive list of well known mime types is provided by
 * the file mime.types in the includes directory.
 */
define('MM_WELL_KNOWN_MIME_TYPES',<<<END_STRING
application/ogg ogg ogm
application/pdf pdf
application/x-javascript js
application/x-shockwave-flash swf
audio/midi mid midi kar
audio/mpeg mpga mpa mp2 mp3
audio/x-aiff aif aiff aifc
audio/x-wav wav
audio/ogg ogg
image/x-bmp bmp
image/gif gif
image/jpeg jpeg jpg jpe
image/png png
image/svg+xml svg
image/tiff tiff tif
image/vnd.djvu djvu
text/plain txt
text/html html htm
video/ogg ogm ogg
video/mpeg mpg mpeg
END_STRING
);

 /** Defines a set of well known mime info entries
 * This is used as a fallback to mime.info files.
 * An extensive list of well known mime types is provided by
 * the file mime.info in the includes directory.
 */
define('MM_WELL_KNOWN_MIME_INFO', <<<END_STRING
application/pdf [OFFICE]
text/javascript application/x-javascript [EXECUTABLE]
application/x-shockwave-flash [MULTIMEDIA]
audio/midi [AUDIO]
audio/x-aiff [AUDIO]
audio/x-wav [AUDIO]
audio/mp3 audio/mpeg [AUDIO]
application/ogg audio/ogg video/ogg [MULTIMEDIA]
image/x-bmp image/bmp [BITMAP]
image/gif [BITMAP]
image/jpeg [BITMAP]
image/png [BITMAP]
image/svg image/svg+xml [DRAWING]
image/tiff [BITMAP]
image/vnd.djvu [BITMAP]
text/plain [TEXT]
text/html [TEXT]
video/ogg [VIDEO]
video/mpeg [VIDEO]
unknown/unknown application/octet-stream application/x-empty [UNKNOWN]
END_STRING
);

#note: because this file is possibly included by a function,
#we need to access the global scope explicitely!
global $wgLoadFileinfoExtension;

if ($wgLoadFileinfoExtension) {
	if(!extension_loaded('fileinfo')) dl('fileinfo.' . PHP_SHLIB_SUFFIX);
}

/** Implements functions related to mime types such as detection and mapping to
* file extension,
*
* Instances of this class are stateles, there only needs to be one global instance
* of MimeMagic. Please use wfGetMimeMagic to get that instance.
* @package MediaWiki
*/
class MimeMagic {

	/**
	* Mapping of media types to arrays of mime types.
	* This is used by findMediaType and getMediaType, respectively
	*/
	var $mMediaTypes= NULL;

	/** Map of mime type aliases
	*/
	var $mMimeTypeAliases= NULL;

	/** map of mime types to file extensions (as a space seprarated list)
	*/
	var $mMimeToExt= NULL;

	/** map of file extensions types to mime types (as a space seprarated list)
	*/
	var $mExtToMime= NULL;

	/** Initializes the MimeMagic object. This is called by wfGetMimeMagic when instantiation
	* the global MimeMagic singleton object.
	*
	* This constructor parses the mime.types and mime.info files and build internal mappings.
	*/
	function MimeMagic() {
		/*
		*   --- load mime.types ---
		*/

		global $wgMimeTypeFile;

		$types= MM_WELL_KNOWN_MIME_TYPES;

		if ($wgMimeTypeFile) {
			if (is_file($wgMimeTypeFile) and is_readable($wgMimeTypeFile)) {
				wfDebug("MimeMagic::MimeMagic: loading mime types from $wgMimeTypeFile\n");

				$types.= "\n";
				$types.= file_get_contents($wgMimeTypeFile);
			}
			else wfDebug("MimeMagic::MimeMagic: can't load mime types from $wgMimeTypeFile\n");
		}
		else wfDebug("MimeMagic::MimeMagic: no mime types file defined, using build-ins only.\n");

		$types= str_replace(array("\r\n","\n\r","\n\n","\r\r","\r"),"\n",$types);
		$types= str_replace("\t"," ",$types);

		$this->mMimeToExt= array();
		$this->mToMime= array();

		$lines= explode("\n",$types);
		foreach ($lines as $s) {
			$s= trim($s);
			if (empty($s)) continue;
			if (strpos($s,'#')===0) continue;

			$s= strtolower($s);
			$i= strpos($s,' ');

			if ($i===false) continue;

			#print "processing MIME line $s<br>";

			$mime= substr($s,0,$i);
			$ext= trim(substr($s,$i+1));

			if (empty($ext)) continue;

			if (@$this->mMimeToExt[$mime]) $this->mMimeToExt[$mime] .= ' '.$ext;
			else $this->mMimeToExt[$mime]= $ext;

			$extensions= explode(' ',$ext);

			foreach ($extensions as $e) {
				$e= trim($e);
				if (empty($e)) continue;

				if (@$this->mExtToMime[$e]) $this->mExtToMime[$e] .= ' '.$mime;
				else $this->mExtToMime[$e]= $mime;
			}
		}

		/*
		*   --- load mime.info ---
		*/

		global $wgMimeInfoFile;

		$info= MM_WELL_KNOWN_MIME_INFO;

		if ($wgMimeInfoFile) {
			if (is_file($wgMimeInfoFile) and is_readable($wgMimeInfoFile)) {
				wfDebug("MimeMagic::MimeMagic: loading mime info from $wgMimeInfoFile\n");

				$info.= "\n";
				$info.= file_get_contents($wgMimeInfoFile);
			}
			else wfDebug("MimeMagic::MimeMagic: can't load mime info from $wgMimeInfoFile\n");
		}
		else wfDebug("MimeMagic::MimeMagic: no mime info file defined, using build-ins only.\n");

		$info= str_replace(array("\r\n","\n\r","\n\n","\r\r","\r"),"\n",$info);
		$info= str_replace("\t"," ",$info);

		$this->mMimeTypeAliases= array();
		$this->mMediaTypes= array();

		$lines= explode("\n",$info);
		foreach ($lines as $s) {
			$s= trim($s);
			if (empty($s)) continue;
			if (strpos($s,'#')===0) continue;

			$s= strtolower($s);
			$i= strpos($s,' ');

			if ($i===false) continue;

			#print "processing MIME INFO line $s<br>";

			$match= array();
			if (preg_match('!\[\s*(\w+)\s*\]!',$s,$match)) {
				$s= preg_replace('!\[\s*(\w+)\s*\]!','',$s);
				$mtype= trim(strtoupper($match[1]));
			}
			else $mtype= MEDIATYPE_UNKNOWN;

			$m= explode(' ',$s);

			if (!isset($this->mMediaTypes[$mtype])) $this->mMediaTypes[$mtype]= array();

			foreach ($m as $mime) {
				$mime= trim($mime);
				if (empty($mime)) continue;

				$this->mMediaTypes[$mtype][]= $mime;
			}

			if (sizeof($m)>1) {
				$main= $m[0];
				for ($i=1; $i<sizeof($m); $i+= 1) {
					$mime= $m[$i];
					$this->mMimeTypeAliases[$mime]= $main;
				}
			}
		}

	}

	/** returns a list of file extensions for a given mime type
	* as a space separated string.
	*/
	function getExtensionsForType($mime) {
		$mime= strtolower($mime);

		$r= @$this->mMimeToExt[$mime];

		if (@!$r and isset($this->mMimeTypeAliases[$mime])) {
			$mime= $this->mMimeTypeAliases[$mime];
			$r= @$this->mMimeToExt[$mime];
		}

		return $r;
	}

	/** returns a list of mime types for a given file extension
	* as a space separated string.
	*/
	function getTypesForExtension($ext) {
		$ext= strtolower($ext);

		$r= @$this->mExtToMime[$ext];
		return $r;
	}

	/** returns a single mime type for a given file extension.
	* This is always the first type from the list returned by getTypesForExtension($ext).
	*/
	function guessTypesForExtension($ext) {
		$m= $this->getTypesForExtension( $ext );
		if( is_null($m) ) return NULL;

		$m= trim( $m );
		$m= preg_replace('/\s.*$/','',$m);

		return $m;
	}


	/** tests if the extension matches the given mime type.
	* returns true if a match was found, NULL if the mime type is unknown,
	* and false if the mime type is known but no matches where found.
	*/
	function isMatchingExtension($extension,$mime) {
		$ext= $this->getExtensionsForType($mime);

		if (!$ext) {
			return NULL;  //unknown
		}

		$ext= explode(' ',$ext);

		$extension= strtolower($extension);
 		if (in_array($extension,$ext)) {
			return true;
		}

		return false;
	}

	/** returns true if the mime type is known to represent
	* an image format supported by the PHP GD library.
	*/
	function isPHPImageType( $mime ) {
		#as defined by imagegetsize and image_type_to_mime
		static $types = array(
			'image/gif', 'image/jpeg', 'image/png',
			'image/x-bmp', 'image/xbm', 'image/tiff',
			'image/jp2', 'image/jpeg2000', 'image/iff',
			'image/xbm', 'image/x-xbitmap',
			'image/vnd.wap.wbmp', 'image/vnd.xiff',
			'image/x-photoshop',
			'application/x-shockwave-flash',
		);

		return in_array( $mime, $types );
	}

	/**
	 * Returns true if the extension represents a type which can
	 * be reliably detected from its content. Use this to determine
	 * whether strict content checks should be applied to reject
	 * invalid uploads; if we can't identify the type we won't
	 * be able to say if it's invalid.
	 *
	 * @todo Be more accurate when using fancy mime detector plugins;
	 *       right now this is the bare minimum getimagesize() list.
	 * @return bool
	 */
	function isRecognizableExtension( $extension ) {
		static $types = array(
			'gif', 'jpeg', 'jpg', 'png', 'swf', 'psd',
			'bmp', 'tiff', 'tif', 'jpc', 'jp2',
			'jpx', 'jb2', 'swc', 'iff', 'wbmp',
			'xbm', 'djvu'
		);
		return in_array( strtolower( $extension ), $types );
	}


	/** mime type detection. This uses detectMimeType to detect the mim type of the file,
	* but applies additional checks to determine some well known file formats that may be missed
	* or misinterpreter by the default mime detection (namely xml based formats like XHTML or SVG).
	*
	* @param string $file The file to check
	* @param bool $useExt switch for allowing to use the file extension to guess the mime type. true by default.
	*
	* @return string the mime type of $file
	*/
	function guessMimeType( $file, $useExt=true ) {
		$fname = 'MimeMagic::guessMimeType';
		$mime= $this->detectMimeType($file,$useExt);

		// Read a chunk of the file
		$f = fopen( $file, "rt" );
		if( !$f ) return "unknown/unknown";
		$head = fread( $f, 1024 );
		fclose( $f );

		$sub4 =  substr( $head, 0, 4 );
		if ( $sub4 == "\x01\x00\x09\x00" || $sub4 == "\xd7\xcd\xc6\x9a" ) {
			// WMF kill kill kill
			// Note that WMF may have a bare header, no magic number.
			// The former of the above two checks is theoretically prone to false positives
			$mime = "application/x-msmetafile";
		}

		if (strpos($mime,"text/")===0 || $mime==="application/xml") {

			$xml_type= NULL;
			$script_type= NULL;

			/*
			* look for XML formats (XHTML and SVG)
			*/
			if ($mime==="text/sgml" ||
			    $mime==="text/plain" ||
			    $mime==="text/html" ||
			    $mime==="text/xml" ||
		            $mime==="application/xml") {

				if (substr($head,0,5)=="<?xml") $xml_type= "ASCII";
				elseif (substr($head,0,8)=="\xef\xbb\xbf<?xml") $xml_type= "UTF-8";
				elseif (substr($head,0,10)=="\xfe\xff\x00<\x00?\x00x\x00m\x00l") $xml_type= "UTF-16BE";
				elseif (substr($head,0,10)=="\xff\xfe<\x00?\x00x\x00m\x00l\x00") $xml_type= "UTF-16LE";

				if ($xml_type) {
					if ($xml_type!=="UTF-8" && $xml_type!=="ASCII") $head= iconv($xml_type,"ASCII//IGNORE",$head);

					$match= array();
					$doctype= "";
					$tag= "";

					if (preg_match('%<!DOCTYPE\s+[\w-]+\s+PUBLIC\s+["'."'".'"](.*?)["'."'".'"].*>%sim',$head,$match)) $doctype= $match[1];
					if (preg_match('%<(\w+).*>%sim',$head,$match)) $tag= $match[1];

					#print "<br>ANALYSING $file ($mime): doctype= $doctype; tag= $tag<br>";

					if (strpos($doctype,"-//W3C//DTD SVG")===0) $mime= "image/svg";
					elseif ($tag==="svg") $mime= "image/svg";
					elseif (strpos($doctype,"-//W3C//DTD XHTML")===0) $mime= "text/html";
					elseif ($tag==="html") $mime= "text/html";

					$test_more= false;
				}
			}

			/*
			* look for shell scripts
			*/
			if (!$xml_type) {
				$script_type= NULL;

				#detect by shebang
				if (substr($head,0,2)=="#!") $script_type= "ASCII";
				elseif (substr($head,0,5)=="\xef\xbb\xbf#!") $script_type= "UTF-8";
				elseif (substr($head,0,7)=="\xfe\xff\x00#\x00!") $script_type= "UTF-16BE";
				elseif (substr($head,0,7)=="\xff\xfe#\x00!") $script_type= "UTF-16LE";

				if ($script_type) {
					if ($script_type!=="UTF-8" && $script_type!=="ASCII") $head= iconv($script_type,"ASCII//IGNORE",$head);

					$match= array();
					$prog= "";

					if (preg_match('%/?([^\s]+/)(w+)%sim',$head,$match)) $script= $match[2];

					$mime= "application/x-$prog";
				}
			}

			/*
			* look for PHP
			*/
			if( !$xml_type && !$script_type ) {

				if( ( strpos( $head, '<?php' ) !== false ) ||
				    ( strpos( $head, '<? ' ) !== false ) ||
				    ( strpos( $head, "<?\n" ) !== false ) ||
				    ( strpos( $head, "<?\t" ) !== false ) ||
				    ( strpos( $head, "<?=" ) !== false ) ||

				    ( strpos( $head, "<\x00?\x00p\x00h\x00p" ) !== false ) ||
				    ( strpos( $head, "<\x00?\x00 " ) !== false ) ||
				    ( strpos( $head, "<\x00?\x00\n" ) !== false ) ||
				    ( strpos( $head, "<\x00?\x00\t" ) !== false ) ||
				    ( strpos( $head, "<\x00?\x00=" ) !== false ) ) {

					$mime= "application/x-php";
				}
			}

		}

		if (isset($this->mMimeTypeAliases[$mime])) $mime= $this->mMimeTypeAliases[$mime];

		wfDebug("$fname: final mime type of $file: $mime\n");
		return $mime;
	}

	/** Internal mime type detection, please use guessMimeType() for application code instead.
	* Detection is done using an external program, if $wgMimeDetectorCommand is set.
	* Otherwise, the fileinfo extension and mime_content_type are tried (in this order), if they are available.
	* If the dections fails and $useExt is true, the mime type is guessed from the file extension, using guessTypesForExtension.
	* If the mime type is still unknown, getimagesize is used to detect the mime type if the file is an image.
	* If no mime type can be determined, this function returns "unknown/unknown".
	*
	* @param string $file The file to check
	* @param bool $useExt switch for allowing to use the file extension to guess the mime type. true by default.
	*
	* @return string the mime type of $file
	* @access private
	*/
	function detectMimeType( $file, $useExt=true ) {
		$fname = 'MimeMagic::detectMimeType';

		global $wgMimeDetectorCommand;

		$m= NULL;
		if ($wgMimeDetectorCommand) {
			$fn= wfEscapeShellArg($file);
			$m= `$wgMimeDetectorCommand $fn`;
		}
		else if (function_exists("finfo_open") && function_exists("finfo_file")) {

			# This required the fileinfo extension by PECL,
			# see http://pecl.php.net/package/fileinfo
			# This must be compiled into PHP
			#
			# finfo is the official replacement for the deprecated
			# mime_content_type function, see below.
			#
			# If you may need to load the fileinfo extension at runtime, set
			# $wgLoadFileinfoExtension in LocalSettings.php

			$mime_magic_resource = finfo_open(FILEINFO_MIME); /* return mime type ala mimetype extension */

			if ($mime_magic_resource) {
				$m= finfo_file($mime_magic_resource, $file);

				finfo_close($mime_magic_resource);
			}
			else wfDebug("$fname: finfo_open failed on ".FILEINFO_MIME."!\n");
		}
		else if (function_exists("mime_content_type")) {

			# NOTE: this function is available since PHP 4.3.0, but only if
			# PHP was compiled with --with-mime-magic or, before 4.3.2, with --enable-mime-magic.
			#
			# On Winodws, you must set mime_magic.magicfile in php.ini to point to the mime.magic file bundeled with PHP;
			# sometimes, this may even be needed under linus/unix.
			#
			# Also note that this has been DEPRECATED in favor of the fileinfo extension by PECL, see above.
			# see http://www.php.net/manual/en/ref.mime-magic.php for details.

			$m= mime_content_type($file);
		}
		else wfDebug("$fname: no magic mime detector found!\n");

		if ($m) {
			#normalize
			$m= preg_replace('![;, ].*$!','',$m); #strip charset, etc
			$m= trim($m);
			$m= strtolower($m);

			if (strpos($m,'unknown')!==false) $m= NULL;
			else {
				wfDebug("$fname: magic mime type of $file: $m\n");
				return $m;
			}
		}

		#if still not known, use getimagesize to find out the type of image
		#TODO: skip things that do not have a well-known image extension? Would that be safe?
		wfSuppressWarnings();
		$gis = getimagesize( $file );
		wfRestoreWarnings();

		$notAnImage= false;

		if ($gis && is_array($gis) && $gis[2]) {
			switch ($gis[2]) {
				case IMAGETYPE_GIF: $m= "image/gif"; break;
				case IMAGETYPE_JPEG: $m= "image/jpeg"; break;
				case IMAGETYPE_PNG: $m= "image/png"; break;
				case IMAGETYPE_SWF: $m= "application/x-shockwave-flash"; break;
				case IMAGETYPE_PSD: $m= "application/photoshop"; break;
				case IMAGETYPE_BMP: $m= "image/bmp"; break;
				case IMAGETYPE_TIFF_II: $m= "image/tiff"; break;
				case IMAGETYPE_TIFF_MM: $m= "image/tiff"; break;
				case IMAGETYPE_JPC: $m= "image"; break;
				case IMAGETYPE_JP2: $m= "image/jpeg2000"; break;
				case IMAGETYPE_JPX: $m= "image/jpeg2000"; break;
				case IMAGETYPE_JB2: $m= "image"; break;
				case IMAGETYPE_SWC: $m= "application/x-shockwave-flash"; break;
				case IMAGETYPE_IFF: $m= "image/vnd.xiff"; break;
				case IMAGETYPE_WBMP: $m= "image/vnd.wap.wbmp"; break;
				case IMAGETYPE_XBM: $m= "image/x-xbitmap"; break;
			}

			if ($m) {
				wfDebug("$fname: image mime type of $file: $m\n");
				return $m;
			}
			else $notAnImage= true;
		} else {
			// Also test DjVu
			$deja = new DjVuImage( $file );
			if( $deja->isValid() ) {
				wfDebug("$fname: detected $file as image/vnd.djvu\n");
				return 'image/vnd.djvu';
			}
		}

		#if desired, look at extension as a fallback.
		if ($useExt) {
			$i = strrpos( $file, '.' );
			$e= strtolower( $i ? substr( $file, $i + 1 ) : '' );

			$m= $this->guessTypesForExtension($e);

			#TODO: if $notAnImage is set, do not trust the file extension if
			# the results is one of the image types that should have been recognized
			# by getimagesize

			if ($m) {
				wfDebug("$fname: extension mime type of $file: $m\n");
				return $m;
			}
		}

		#unknown type
		wfDebug("$fname: failed to guess mime type for $file!\n");
		return "unknown/unknown";
	}

	/**
	* Determine the media type code for a file, using its mime type, name and possibly
	* its contents.
	*
	* This function relies on the findMediaType(), mapping extensions and mime
	* types to media types.
	*
	* @todo analyse file if need be
	* @todo look at multiple extension, separately and together.
	*
	* @param string $path full path to the image file, in case we have to look at the contents
	*        (if null, only the mime type is used to determine the media type code).
	* @param string $mime mime type. If null it will be guessed using guessMimeType.
	*
	* @return (int?string?) a value to be used with the MEDIATYPE_xxx constants.
	*/
	function getMediaType($path=NULL,$mime=NULL) {
		if( !$mime && !$path ) return MEDIATYPE_UNKNOWN;

		#if mime type is unknown, guess it
		if( !$mime ) $mime= $this->guessMimeType($path,false);

		#special code for ogg - detect if it's video (theora),
		#else label it as sound.
		if( $mime=="application/ogg" && file_exists($path) ) {

			// Read a chunk of the file
			$f = fopen( $path, "rt" );
			if( !$f ) return MEDIATYPE_UNKNOWN;
			$head = fread( $f, 256 );
			fclose( $f );

			$head= strtolower( $head );

			#This is an UGLY HACK, file should be parsed correctly
			if( strpos($head,'theora')!==false ) return MEDIATYPE_VIDEO;
			elseif( strpos($head,'vorbis')!==false ) return MEDIATYPE_AUDIO;
			elseif( strpos($head,'flac')!==false ) return MEDIATYPE_AUDIO;
			elseif( strpos($head,'speex')!==false ) return MEDIATYPE_AUDIO;
			else return MEDIATYPE_MULTIMEDIA;
		}

		#check for entry for full mime type
		if( $mime ) {
			$type= $this->findMediaType($mime);
			if( $type!==MEDIATYPE_UNKNOWN ) return $type;
		}

		#check for entry for file extension
		$e= NULL;
		if( $path ) {
			$i = strrpos( $path, '.' );
			$e= strtolower( $i ? substr( $path, $i + 1 ) : '' );

			#TODO: look at multi-extension if this fails, parse from full path

			$type= $this->findMediaType('.'.$e);
			if( $type!==MEDIATYPE_UNKNOWN ) return $type;
		}

		#check major mime type
		if( $mime ) {
			$i= strpos($mime,'/');
			if( $i !== false ) {
				$major= substr($mime,0,$i);
				$type= $this->findMediaType($major);
				if( $type!==MEDIATYPE_UNKNOWN ) return $type;
			}
		}

		if( !$type ) $type= MEDIATYPE_UNKNOWN;

		return $type;
	}

	/** returns a media code matching the given mime type or file extension.
	* File extensions are represented by a string starting with a dot (.) to
	* distinguish them from mime types.
	*
	* This funktion relies on the mapping defined by $this->mMediaTypes
	* @access private
	*/
	function findMediaType($extMime) {

		if (strpos($extMime,'.')===0) { #if it's an extension, look up the mime types
			$m= $this->getTypesForExtension(substr($extMime,1));
			if (!$m) return MEDIATYPE_UNKNOWN;

			$m= explode(' ',$m);
		}
		else { #normalize mime type
			if (isset($this->mMimeTypeAliases[$extMime])) {
				$extMime= $this->mMimeTypeAliases[$extMime];
			}

			$m= array($extMime);
		}

		foreach ($m as $mime) {
			foreach ($this->mMediaTypes as $type => $codes) {
				if (in_array($mime,$codes,true)) return $type;
			}
		}

		return MEDIATYPE_UNKNOWN;
	}
}

?>