includes/MimeMagic.php

   1 <?php
   2 /** Module defining helper functions for detecting and dealing with mime types.
   3  *
   4  * @package MediaWiki
   5  */
   6
   7  /** Defines a set of well known mime types
   8  * This is used as a fallback to mime.types files.
   9  * An extensive list of well known mime types is provided by
  10  * the file mime.types in the includes directory.
  11  */
  12 define('MM_WELL_KNOWN_MIME_TYPES',<<<END_STRING
  13 application/ogg ogg ogm
  14 application/pdf pdf
  15 application/x-javascript js
  16 application/x-shockwave-flash swf
  17 audio/midi mid midi kar
  18 audio/mpeg mpga mpa mp2 mp3
  19 audio/x-aiff aif aiff aifc
  20 audio/x-wav wav
  21 audio/ogg ogg
  22 image/x-bmp bmp
  23 image/gif gif
  24 image/jpeg jpeg jpg jpe
  25 image/png png
  26 image/svg+xml svg
  27 image/tiff tiff tif
  28 text/plain txt
  29 text/html html htm
  30 video/ogg ogm ogg
  31 video/mpeg mpg mpeg
  32 END_STRING
  33 );
  34
  35  /** Defines a set of well known mime info entries
  36  * This is used as a fallback to mime.info files.
  37  * An extensive list of well known mime types is provided by
  38  * the file mime.info in the includes directory.
  39  */
  40 define('MM_WELL_KNOWN_MIME_INFO', <<<END_STRING
  41 application/pdf [OFFICE]
  42 text/javascript application/x-javascript [EXECUTABLE]
  43 application/x-shockwave-flash [MULTIMEDIA]
  44 audio/midi [AUDIO]
  45 audio/x-aiff [AUDIO]
  46 audio/x-wav [AUDIO]
  47 audio/mp3 audio/mpeg [AUDIO]
  48 application/ogg audio/ogg video/ogg [MULTIMEDIA]
  49 image/x-bmp image/bmp [BITMAP]
  50 image/gif [BITMAP]
  51 image/jpeg [BITMAP]
  52 image/png [BITMAP]
  53 image/svg image/svg+xml [DRAWING]
  54 image/tiff [BITMAP]
  55 text/plain [TEXT]
  56 text/html [TEXT]
  57 video/ogg [VIDEO]
  58 video/mpeg [VIDEO]
  59 unknown/unknown application/octet-stream application/x-empty [UNKNOWN]
  60 END_STRING
  61 );
  62
  63 #note: because this file is possibly included by a function,
  64 #we need to access the global scope explicitely!
  65 global $wgLoadFileinfoExtension;
  66
  67 if ($wgLoadFileinfoExtension) {
  68         if(!extension_loaded('fileinfo')) dl('fileinfo.' . PHP_SHLIB_SUFFIX);
  69 }
  70
  71 /** Implements functions related to mime types such as detection and mapping to
  72 * file extension,
  73 *
  74 * Instances of this class are stateles, there only needs to be one global instance
  75 * of MimeMagic. Please use wfGetMimeMagic to get that instance.
  76 * @package MediaWiki
  77 */
  78 class MimeMagic {
  79
  80         /**
  81         * Mapping of media types to arrays of mime types.
  82         * This is used by findMediaType and getMediaType, respectively
  83         */
  84         var $mMediaTypes= NULL;
  85
  86         /** Map of mime type aliases
  87         */
  88         var $mMimeTypeAliases= NULL;
  89
  90         /** map of mime types to file extensions (as a space seprarated list)
  91         */
  92         var $mMimeToExt= NULL;
  93
  94         /** map of file extensions types to mime types (as a space seprarated list)
  95         */
  96         var $mExtToMime= NULL;
  97
  98         /** Initializes the MimeMagic object. This is called by wfGetMimeMagic when instantiation
  99         * the global MimeMagic singleton object.
 100         *
 101         * This constructor parses the mime.types and mime.info files and build internal mappings.
 102         */
 103         function MimeMagic() {
 104                 /*
 105                 *   --- load mime.types ---
 106                 */
 107
 108                 global $wgMimeTypeFile;
 109
 110                 $types= MM_WELL_KNOWN_MIME_TYPES;
 111
 112                 if ($wgMimeTypeFile) {
 113                         if (is_file($wgMimeTypeFile) and is_readable($wgMimeTypeFile)) {
 114                                 wfDebug("MimeMagic::MimeMagic: loading mime types from $wgMimeTypeFile\n");
 115
 116                                 $types.= "\n";
 117                                 $types.= file_get_contents($wgMimeTypeFile);
 118                         }
 119                         else wfDebug("MimeMagic::MimeMagic: can't load mime types from $wgMimeTypeFile\n");
 120                 }
 121                 else wfDebug("MimeMagic::MimeMagic: no mime types file defined, using build-ins only.\n");
 122
 123                 $types= str_replace(array("\r\n","\n\r","\n\n","\r\r","\r"),"\n",$types);
 124                 $types= str_replace("\t"," ",$types);
 125
 126                 $this->mMimeToExt= array();
 127                 $this->mToMime= array();
 128
 129                 $lines= explode("\n",$types);
 130                 foreach ($lines as $s) {
 131                         $s= trim($s);
 132                         if (empty($s)) continue;
 133                         if (strpos($s,'#')===0) continue;
 134
 135                         $s= strtolower($s);
 136                         $i= strpos($s,' ');
 137
 138                         if ($i===false) continue;
 139
 140                         #print "processing MIME line $s<br>";
 141
 142                         $mime= substr($s,0,$i);
 143                         $ext= trim(substr($s,$i+1));
 144
 145                         if (empty($ext)) continue;
 146
 147                         if (@$this->mMimeToExt[$mime]) $this->mMimeToExt[$mime] .= ' '.$ext;
 148                         else $this->mMimeToExt[$mime]= $ext;
 149
 150                         $extensions= explode(' ',$ext);
 151
 152                         foreach ($extensions as $e) {
 153                                 $e= trim($e);
 154                                 if (empty($e)) continue;
 155
 156                                 if (@$this->mExtToMime[$e]) $this->mExtToMime[$e] .= ' '.$mime;
 157                                 else $this->mExtToMime[$e]= $mime;
 158                         }
 159                 }
 160
 161                 /*
 162                 *   --- load mime.info ---
 163                 */
 164
 165                 global $wgMimeInfoFile;
 166
 167                 $info= MM_WELL_KNOWN_MIME_INFO;
 168
 169                 if ($wgMimeInfoFile) {
 170                         if (is_file($wgMimeInfoFile) and is_readable($wgMimeInfoFile)) {
 171                                 wfDebug("MimeMagic::MimeMagic: loading mime info from $wgMimeInfoFile\n");
 172
 173                                 $info.= "\n";
 174                                 $info.= file_get_contents($wgMimeInfoFile);
 175                         }
 176                         else wfDebug("MimeMagic::MimeMagic: can't load mime info from $wgMimeInfoFile\n");
 177                 }
 178                 else wfDebug("MimeMagic::MimeMagic: no mime info file defined, using build-ins only.\n");
 179
 180                 $info= str_replace(array("\r\n","\n\r","\n\n","\r\r","\r"),"\n",$info);
 181                 $info= str_replace("\t"," ",$info);
 182
 183                 $this->mMimeTypeAliases= array();
 184                 $this->mMediaTypes= array();
 185
 186                 $lines= explode("\n",$info);
 187                 foreach ($lines as $s) {
 188                         $s= trim($s);
 189                         if (empty($s)) continue;
 190                         if (strpos($s,'#')===0) continue;
 191
 192                         $s= strtolower($s);
 193                         $i= strpos($s,' ');
 194
 195                         if ($i===false) continue;
 196
 197                         #print "processing MIME INFO line $s<br>";
 198
 199                         $match= array();
 200                         if (preg_match('!\[\s*(\w+)\s*\]!',$s,$match)) {
 201                                 $s= preg_replace('!\[\s*(\w+)\s*\]!','',$s);
 202                                 $mtype= trim(strtoupper($match[1]));
 203                         }
 204                         else $mtype= MEDIATYPE_UNKNOWN;
 205
 206                         $m= explode(' ',$s);
 207
 208                         if (!isset($this->mMediaTypes[$mtype])) $this->mMediaTypes[$mtype]= array();
 209
 210                         foreach ($m as $mime) {
 211                                 $mime= trim($mime);
 212                                 if (empty($mime)) continue;
 213
 214                                 $this->mMediaTypes[$mtype][]= $mime;
 215                         }
 216
 217                         if (sizeof($m)>1) {
 218                                 $main= $m[0];
 219                                 for ($i=1; $i<sizeof($m); $i+= 1) {
 220                                         $mime= $m[$i];
 221                                         $this->mMimeTypeAliases[$mime]= $main;
 222                                 }
 223                         }
 224                 }
 225
 226         }
 227
 228         /** returns a list of file extensions for a given mime type
 229         * as a space separated string.
 230         */
 231         function getExtensionsForType($mime) {
 232                 $mime= strtolower($mime);
 233
 234                 $r= @$this->mMimeToExt[$mime];
 235
 236                 if (@!$r and isset($this->mMimeTypeAliases[$mime])) {
 237                         $mime= $this->mMimeTypeAliases[$mime];
 238                         $r= @$this->mMimeToExt[$mime];
 239                 }
 240
 241                 return $r;
 242         }
 243
 244         /** returns a list of mime types for a given file extension
 245         * as a space separated string.
 246         */
 247         function getTypesForExtension($ext) {
 248                 $ext= strtolower($ext);
 249
 250                 $r= @$this->mExtToMime[$ext];
 251                 return $r;
 252         }
 253
 254         /** returns a single mime type for a given file extension.
 255         * This is always the first type from the list returned by getTypesForExtension($ext).
 256         */
 257         function guessTypesForExtension($ext) {
 258                 $m= $this->getTypesForExtension( $ext );
 259                 if( is_null($m) ) return NULL;
 260
 261                 $m= trim( $m );
 262                 $m= preg_replace('/\s.*$/','',$m);
 263
 264                 return $m;
 265         }
 266
 267
 268         /** tests if the extension matches the given mime type.
 269         * returns true if a match was found, NULL if the mime type is unknown,
 270         * and false if the mime type is known but no matches where found.
 271         */
 272         function isMatchingExtension($extension,$mime) {
 273                 $ext= $this->getExtensionsForType($mime);
 274
 275                 if (!$ext) {
 276                         return NULL;  //unknown
 277                 }
 278
 279                 $ext= explode(' ',$ext);
 280
 281                 $extension= strtolower($extension);
 282                 if (in_array($extension,$ext)) {
 283                         return true;
 284                 }
 285
 286                 return false;
 287         }
 288
 289         /** returns true if the mime type is known to represent
 290         * an image format supported by the PHP GD library.
 291         */
 292         function isPHPImageType( $mime ) {
 293                 #as defined by imagegetsize and image_type_to_mime
 294                 static $types = array(
 295                         'image/gif', 'image/jpeg', 'image/png',
 296                         'image/x-bmp', 'image/xbm', 'image/tiff',
 297                         'image/jp2', 'image/jpeg2000', 'image/iff',
 298                         'image/xbm', 'image/x-xbitmap',
 299                         'image/vnd.wap.wbmp', 'image/vnd.xiff',
 300                         'image/x-photoshop',
 301                         'application/x-shockwave-flash',
 302                 );
 303
 304                 return in_array( $mime, $types );
 305         }
 306
 307         /**
 308          * Returns true if the extension represents a type which can
 309          * be reliably detected from its content. Use this to determine
 310          * whether strict content checks should be applied to reject
 311          * invalid uploads; if we can't identify the type we won't
 312          * be able to say if it's invalid.
 313          *
 314          * @todo Be more accurate when using fancy mime detector plugins;
 315          *       right now this is the bare minimum getimagesize() list.
 316          * @return bool
 317          */
 318         function isRecognizableExtension( $extension ) {
 319                 static $types = array(
 320                         'gif', 'jpeg', 'jpg', 'png', 'swf', 'psd',
 321                         'bmp', 'tiff', 'tif', 'jpc', 'jp2',
 322                         'jpx', 'jb2', 'swc', 'iff', 'wbmp',
 323                         'xbm'
 324                 );
 325                 return in_array( strtolower( $extension ), $types );
 326         }
 327
 328
 329         /** mime type detection. This uses detectMimeType to detect the mim type of the file,
 330         * but applies additional checks to determine some well known file formats that may be missed
 331         * or misinterpreter by the default mime detection (namely xml based formats like XHTML or SVG).
 332         *
 333         * @param string $file The file to check
 334         * @param bool $useExt switch for allowing to use the file extension to guess the mime type. true by default.
 335         *
 336         * @return string the mime type of $file
 337         */
 338         function guessMimeType( $file, $useExt=true ) {
 339                 $fname = 'MimeMagic::guessMimeType';
 340                 $mime= $this->detectMimeType($file,$useExt);
 341
 342                 // Read a chunk of the file
 343                 $f = fopen( $file, "rt" );
 344                 if( !$f ) return "unknown/unknown";
 345                 $head = fread( $f, 1024 );
 346                 fclose( $f );
 347
 348                 $sub4 =  substr( $head, 0, 4 );
 349                 if ( $sub4 == "\x01\x00\x09\x00" || $sub4 == "\xd7\xcd\xc6\x9a" ) {
 350                         // WMF kill kill kill
 351                         // Note that WMF may have a bare header, no magic number.
 352                         // The former of the above two checks is theoretically prone to false positives
 353                         $mime = "application/x-msmetafile";
 354                 }
 355
 356                 if (strpos($mime,"text/")===0 || $mime==="application/xml") {
 357
 358                         $xml_type= NULL;
 359                         $script_type= NULL;
 360
 361                         /*
 362                         * look for XML formats (XHTML and SVG)
 363                         */
 364                         if ($mime==="text/sgml" ||
 365                             $mime==="text/plain" ||
 366                             $mime==="text/html" ||
 367                             $mime==="text/xml" ||
 368                             $mime==="application/xml") {
 369
 370                                 if (substr($head,0,5)=="<?xml") $xml_type= "ASCII";
 371                                 elseif (substr($head,0,8)=="\xef\xbb\xbf<?xml") $xml_type= "UTF-8";
 372                                 elseif (substr($head,0,10)=="\xfe\xff\x00<\x00?\x00x\x00m\x00l") $xml_type= "UTF-16BE";
 373                                 elseif (substr($head,0,10)=="\xff\xfe<\x00?\x00x\x00m\x00l\x00") $xml_type= "UTF-16LE";
 374
 375                                 if ($xml_type) {
 376                                         if ($xml_type!=="UTF-8" && $xml_type!=="ASCII") $head= iconv($xml_type,"ASCII//IGNORE",$head);
 377
 378                                         $match= array();
 379                                         $doctype= "";
 380                                         $tag= "";
 381
 382                                         if (preg_match('%<!DOCTYPE\s+[\w-]+\s+PUBLIC\s+["'."'".'"](.*?)["'."'".'"].*>%sim',$head,$match)) $doctype= $match[1];
 383                                         if (preg_match('%<(\w+).*>%sim',$head,$match)) $tag= $match[1];
 384
 385                                         #print "<br>ANALYSING $file ($mime): doctype= $doctype; tag= $tag<br>";
 386
 387                                         if (strpos($doctype,"-//W3C//DTD SVG")===0) $mime= "image/svg";
 388                                         elseif ($tag==="svg") $mime= "image/svg";
 389                                         elseif (strpos($doctype,"-//W3C//DTD XHTML")===0) $mime= "text/html";
 390                                         elseif ($tag==="html") $mime= "text/html";
 391
 392                                         $test_more= false;
 393                                 }
 394                         }
 395
 396                         /*
 397                         * look for shell scripts
 398                         */
 399                         if (!$xml_type) {
 400                                 $script_type= NULL;
 401
 402                                 #detect by shebang
 403                                 if (substr($head,0,2)=="#!") $script_type= "ASCII";
 404                                 elseif (substr($head,0,5)=="\xef\xbb\xbf#!") $script_type= "UTF-8";
 405                                 elseif (substr($head,0,7)=="\xfe\xff\x00#\x00!") $script_type= "UTF-16BE";
 406                                 elseif (substr($head,0,7)=="\xff\xfe#\x00!") $script_type= "UTF-16LE";
 407
 408                                 if ($script_type) {
 409                                         if ($script_type!=="UTF-8" && $script_type!=="ASCII") $head= iconv($script_type,"ASCII//IGNORE",$head);
 410
 411                                         $match= array();
 412                                         $prog= "";
 413
 414                                         if (preg_match('%/?([^\s]+/)(w+)%sim',$head,$match)) $script= $match[2];
 415
 416                                         $mime= "application/x-$prog";
 417                                 }
 418                         }
 419
 420                         /*
 421                         * look for PHP
 422                         */
 423                         if( !$xml_type && !$script_type ) {
 424
 425                                 if( ( strpos( $head, '<?php' ) !== false ) ||
 426                                     ( strpos( $head, '<? ' ) !== false ) ||
 427                                     ( strpos( $head, "<?\n" ) !== false ) ||
 428                                     ( strpos( $head, "<?\t" ) !== false ) ||
 429                                     ( strpos( $head, "<?=" ) !== false ) ||
 430
 431                                     ( strpos( $head, "<\x00?\x00p\x00h\x00p" ) !== false ) ||
 432                                     ( strpos( $head, "<\x00?\x00 " ) !== false ) ||
 433                                     ( strpos( $head, "<\x00?\x00\n" ) !== false ) ||
 434                                     ( strpos( $head, "<\x00?\x00\t" ) !== false ) ||
 435                                     ( strpos( $head, "<\x00?\x00=" ) !== false ) ) {
 436
 437                                         $mime= "application/x-php";
 438                                 }
 439                         }
 440
 441                 }
 442
 443                 if (isset($this->mMimeTypeAliases[$mime])) $mime= $this->mMimeTypeAliases[$mime];
 444
 445                 wfDebug("$fname: final mime type of $file: $mime\n");
 446                 return $mime;
 447         }
 448
 449         /** Internal mime type detection, please use guessMimeType() for application code instead.
 450         * Detection is done using an external program, if $wgMimeDetectorCommand is set.
 451         * Otherwise, the fileinfo extension and mime_content_type are tried (in this order), if they are available.
 452         * If the dections fails and $useExt is true, the mime type is guessed from the file extension, using guessTypesForExtension.
 453         * If the mime type is still unknown, getimagesize is used to detect the mime type if the file is an image.
 454         * If no mime type can be determined, this function returns "unknown/unknown".
 455         *
 456         * @param string $file The file to check
 457         * @param bool $useExt switch for allowing to use the file extension to guess the mime type. true by default.
 458         *
 459         * @return string the mime type of $file
 460         * @access private
 461         */
 462         function detectMimeType( $file, $useExt=true ) {
 463                 $fname = 'MimeMagic::detectMimeType';
 464
 465                 global $wgMimeDetectorCommand;
 466
 467                 $m= NULL;
 468                 if ($wgMimeDetectorCommand) {
 469                         $fn= wfEscapeShellArg($file);
 470                         $m= `$wgMimeDetectorCommand $fn`;
 471                 }
 472                 else if (function_exists("finfo_open") && function_exists("finfo_file")) {
 473
 474                         # This required the fileinfo extension by PECL,
 475                         # see http://pecl.php.net/package/fileinfo
 476                         # This must be compiled into PHP
 477                         #
 478                         # finfo is the official replacement for the deprecated
 479                         # mime_content_type function, see below.
 480                         #
 481                         # If you may need to load the fileinfo extension at runtime, set
 482                         # $wgLoadFileinfoExtension in LocalSettings.php
 483
 484                         $mime_magic_resource = finfo_open(FILEINFO_MIME); /* return mime type ala mimetype extension */
 485
 486                         if ($mime_magic_resource) {
 487                                 $m= finfo_file($mime_magic_resource, $file);
 488
 489                                 finfo_close($mime_magic_resource);
 490                         }
 491                         else wfDebug("$fname: finfo_open failed on ".FILEINFO_MIME."!\n");
 492                 }
 493                 else if (function_exists("mime_content_type")) {
 494
 495                         # NOTE: this function is available since PHP 4.3.0, but only if
 496                         # PHP was compiled with --with-mime-magic or, before 4.3.2, with --enable-mime-magic.
 497                         #
 498                         # On Winodws, you must set mime_magic.magicfile in php.ini to point to the mime.magic file bundeled with PHP;
 499                         # sometimes, this may even be needed under linus/unix.
 500                         #
 501                         # Also note that this has been DEPRECATED in favor of the fileinfo extension by PECL, see above.
 502                         # see http://www.php.net/manual/en/ref.mime-magic.php for details.
 503
 504                         $m= mime_content_type($file);
 505                 }
 506                 else wfDebug("$fname: no magic mime detector found!\n");
 507
 508                 if ($m) {
 509                         #normalize
 510                         $m= preg_replace('![;, ].*$!','',$m); #strip charset, etc
 511                         $m= trim($m);
 512                         $m= strtolower($m);
 513
 514                         if (strpos($m,'unknown')!==false) $m= NULL;
 515                         else {
 516                                 wfDebug("$fname: magic mime type of $file: $m\n");
 517                                 return $m;
 518                         }
 519                 }
 520
 521                 #if still not known, use getimagesize to find out the type of image
 522                 #TODO: skip things that do not have a well-known image extension? Would that be safe?
 523                 wfSuppressWarnings();
 524                 $gis = getimagesize( $file );
 525                 wfRestoreWarnings();
 526
 527                 $notAnImage= false;
 528
 529                 if ($gis && is_array($gis) && $gis[2]) {
 530                         switch ($gis[2]) {
 531                                 case IMAGETYPE_GIF: $m= "image/gif"; break;
 532                                 case IMAGETYPE_JPEG: $m= "image/jpeg"; break;
 533                                 case IMAGETYPE_PNG: $m= "image/png"; break;
 534                                 case IMAGETYPE_SWF: $m= "application/x-shockwave-flash"; break;
 535                                 case IMAGETYPE_PSD: $m= "application/photoshop"; break;
 536                                 case IMAGETYPE_BMP: $m= "image/bmp"; break;
 537                                 case IMAGETYPE_TIFF_II: $m= "image/tiff"; break;
 538                                 case IMAGETYPE_TIFF_MM: $m= "image/tiff"; break;
 539                                 case IMAGETYPE_JPC: $m= "image"; break;
 540                                 case IMAGETYPE_JP2: $m= "image/jpeg2000"; break;
 541                                 case IMAGETYPE_JPX: $m= "image/jpeg2000"; break;
 542                                 case IMAGETYPE_JB2: $m= "image"; break;
 543                                 case IMAGETYPE_SWC: $m= "application/x-shockwave-flash"; break;
 544                                 case IMAGETYPE_IFF: $m= "image/vnd.xiff"; break;
 545                                 case IMAGETYPE_WBMP: $m= "image/vnd.wap.wbmp"; break;
 546                                 case IMAGETYPE_XBM: $m= "image/x-xbitmap"; break;
 547                         }
 548
 549                         if ($m) {
 550                                 wfDebug("$fname: image mime type of $file: $m\n");
 551                                 return $m;
 552                         }
 553                         else $notAnImage= true;
 554                 }
 555
 556                 #if desired, look at extension as a fallback.
 557                 if ($useExt) {
 558                         $i = strrpos( $file, '.' );
 559                         $e= strtolower( $i ? substr( $file, $i + 1 ) : '' );
 560
 561                         $m= $this->guessTypesForExtension($e);
 562
 563                         #TODO: if $notAnImage is set, do not trust the file extension if
 564                         # the results is one of the image types that should have been recognized
 565                         # by getimagesize
 566
 567                         if ($m) {
 568                                 wfDebug("$fname: extension mime type of $file: $m\n");
 569                                 return $m;
 570                         }
 571                 }
 572
 573                 #unknown type
 574                 wfDebug("$fname: failed to guess mime type for $file!\n");
 575                 return "unknown/unknown";
 576         }
 577
 578         /**
 579         * Determine the media type code for a file, using its mime type, name and possibly
 580         * its contents.
 581         *
 582         * This function relies on the findMediaType(), mapping extensions and mime
 583         * types to media types.
 584         *
 585         * @todo analyse file if need be
 586         * @todo look at multiple extension, separately and together.
 587         *
 588         * @param string $path full path to the image file, in case we have to look at the contents
 589         *        (if null, only the mime type is used to determine the media type code).
 590         * @param string $mime mime type. If null it will be guessed using guessMimeType.
 591         *
 592         * @return (int?string?) a value to be used with the MEDIATYPE_xxx constants.
 593         */
 594         function getMediaType($path=NULL,$mime=NULL) {
 595                 if( !$mime && !$path ) return MEDIATYPE_UNKNOWN;
 596
 597                 #if mime type is unknown, guess it
 598                 if( !$mime ) $mime= $this->guessMimeType($path,false);
 599
 600                 #special code for ogg - detect if it's video (theora),
 601                 #else label it as sound.
 602                 if( $mime=="application/ogg" && file_exists($path) ) {
 603
 604                         // Read a chunk of the file
 605                         $f = fopen( $path, "rt" );
 606                         if( !$f ) return MEDIATYPE_UNKNOWN;
 607                         $head = fread( $f, 256 );
 608                         fclose( $f );
 609
 610                         $head= strtolower( $head );
 611
 612                         #This is an UGLY HACK, file should be parsed correctly
 613                         if( strpos($head,'theora')!==false ) return MEDIATYPE_VIDEO;
 614                         elseif( strpos($head,'vorbis')!==false ) return MEDIATYPE_AUDIO;
 615                         elseif( strpos($head,'flac')!==false ) return MEDIATYPE_AUDIO;
 616                         elseif( strpos($head,'speex')!==false ) return MEDIATYPE_AUDIO;
 617                         else return MEDIATYPE_MULTIMEDIA;
 618                 }
 619
 620                 #check for entry for full mime type
 621                 if( $mime ) {
 622                         $type= $this->findMediaType($mime);
 623                         if( $type!==MEDIATYPE_UNKNOWN ) return $type;
 624                 }
 625
 626                 #check for entry for file extension
 627                 $e= NULL;
 628                 if( $path ) {
 629                         $i = strrpos( $path, '.' );
 630                         $e= strtolower( $i ? substr( $path, $i + 1 ) : '' );
 631
 632                         #TODO: look at multi-extension if this fails, parse from full path
 633
 634                         $type= $this->findMediaType('.'.$e);
 635                         if( $type!==MEDIATYPE_UNKNOWN ) return $type;
 636                 }
 637
 638                 #check major mime type
 639                 if( $mime ) {
 640                         $i= strpos($mime,'/');
 641                         if( $i !== false ) {
 642                                 $major= substr($mime,0,$i);
 643                                 $type= $this->findMediaType($major);
 644                                 if( $type!==MEDIATYPE_UNKNOWN ) return $type;
 645                         }
 646                 }
 647
 648                 if( !$type ) $type= MEDIATYPE_UNKNOWN;
 649
 650                 return $type;
 651         }
 652
 653         /** returns a media code matching the given mime type or file extension.
 654         * File extensions are represented by a string starting with a dot (.) to
 655         * distinguish them from mime types.
 656         *
 657         * This funktion relies on the mapping defined by $this->mMediaTypes
 658         * @access private
 659         */
 660         function findMediaType($extMime) {
 661
 662                 if (strpos($extMime,'.')===0) { #if it's an extension, look up the mime types
 663                         $m= $this->getTypesForExtension(substr($extMime,1));
 664                         if (!$m) return MEDIATYPE_UNKNOWN;
 665
 666                         $m= explode(' ',$m);
 667                 }
 668                 else { #normalize mime type
 669                         if (isset($this->mMimeTypeAliases[$extMime])) {
 670                                 $extMime= $this->mMimeTypeAliases[$extMime];
 671                         }
 672
 673                         $m= array($extMime);
 674                 }
 675
 676                 foreach ($m as $mime) {
 677                         foreach ($this->mMediaTypes as $type => $codes) {
 678                                 if (in_array($mime,$codes,true)) return $type;
 679                         }
 680                 }
 681
 682                 return MEDIATYPE_UNKNOWN;
 683         }
 684 }
 685
 686 ?>