includes/media/Bitmap.php

   1 <?php
   2 /**
   3  * Generic handler for bitmap images
   4  *
   5  * @file
   6  * @ingroup Media
   7  */
   8
   9 /**
  10  * Generic handler for bitmap images
  11  *
  12  * @ingroup Media
  13  */
  14 class BitmapHandler extends ImageHandler {
  15
  16         /**
  17          * @param $image File
  18          * @param  $params
  19          * @return bool
  20          */
  21         function normaliseParams( $image, &$params ) {
  22                 global $wgMaxImageArea;
  23                 if ( !parent::normaliseParams( $image, $params ) ) {
  24                         return false;
  25                 }
  26
  27                 $mimeType = $image->getMimeType();
  28                 $srcWidth = $image->getWidth( $params['page'] );
  29                 $srcHeight = $image->getHeight( $params['page'] );
  30
  31                 $swapDimensions = false;
  32                 if ( self::canRotate() ) {
  33                         $rotation = $this->getRotation( $image );
  34                         if ( $rotation == 90 || $rotation == 270 ) {
  35                                 wfDebug( __METHOD__ . ": Swapping width and height because the file will be rotated $rotation degrees\n" );
  36
  37                                 $swapDimensions = true;
  38                                 list( $params['width'], $params['height'] ) =
  39                                         array(  $params['width'], $params['height'] );
  40                                 list( $params['physicalWidth'], $params['physicalHeight'] ) =
  41                                         array( $params['physicalWidth'], $params['physicalHeight'] );
  42                         }
  43                 }
  44
  45                 # Don't make an image bigger than the source
  46                 if ( $params['physicalWidth'] >= $srcWidth ) {
  47                         if ( $swapDimensions ) {
  48                                 $params['physicalWidth'] = $srcHeight;
  49                                 $params['physicalHeight'] = $srcWidth;
  50                         } else {
  51                                 $params['physicalWidth'] = $srcWidth;
  52                                 $params['physicalHeight'] = $srcHeight;
  53                         }
  54                 }
  55
  56                 # Skip scaling limit checks if no scaling is required
  57                 if ( !$image->mustRender() )
  58                         return true;
  59
  60                 # Don't thumbnail an image so big that it will fill hard drives and send servers into swap
  61                 # JPEG has the handy property of allowing thumbnailing without full decompression, so we make
  62                 # an exception for it.
  63                 # @todo FIXME: This actually only applies to ImageMagick
  64                 if ( $mimeType !== 'image/jpeg' &&
  65                         $srcWidth * $srcHeight > $wgMaxImageArea )
  66                 {
  67                         return false;
  68                 }
  69
  70                 return true;
  71         }
  72
  73         /**
  74          * Extracts the width/height if the image will be scaled before rotating
  75          *
  76          * @param $params array Parameters as returned by normaliseParams
  77          * @param $rotation int The rotation angle that will be applied
  78          * @return array ($width, $height) array
  79          */
  80         public function extractPreRotationDimensions( $params, $rotation ) {
  81                 if ( $rotation == 90 || $rotation == 270 ) {
  82                         # We'll resize before rotation, so swap the dimensions again
  83                         $width = $params['physicalHeight'];
  84                         $height = $params['physicalWidth'];
  85                 } else {
  86                         $width = $params['physicalWidth'];
  87                         $height = $params['physicalHeight'];
  88                 }
  89                 return array( $width, $height );
  90         }
  91
  92
  93         // Function that returns the number of pixels to be thumbnailed.
  94         // Intended for animated GIFs to multiply by the number of frames.
  95         function getImageArea( $image, $width, $height ) {
  96                 return $width * $height;
  97         }
  98
  99         /**
 100          * @param $image File
 101          * @param  $dstPath
 102          * @param  $dstUrl
 103          * @param  $params
 104          * @param int $flags
 105          * @return MediaTransformError|ThumbnailImage|TransformParameterError
 106          */
 107         function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
 108                 if ( !$this->normaliseParams( $image, $params ) ) {
 109                         return new TransformParameterError( $params );
 110                 }
 111                 # Create a parameter array to pass to the scaler
 112                 $scalerParams = array(
 113                         # The size to which the image will be resized
 114                         'physicalWidth' => $params['physicalWidth'],
 115                         'physicalHeight' => $params['physicalHeight'],
 116                         'physicalDimensions' => "{$params['physicalWidth']}x{$params['physicalHeight']}",
 117                         # The size of the image on the page
 118                         'clientWidth' => $params['width'],
 119                         'clientHeight' => $params['height'],
 120                         # Comment as will be added to the EXIF of the thumbnail
 121                         'comment' => isset( $params['descriptionUrl'] ) ?
 122                                 "File source: {$params['descriptionUrl']}" : '',
 123                         # Properties of the original image
 124                         'srcWidth' => $image->getWidth(),
 125                         'srcHeight' => $image->getHeight(),
 126                         'mimeType' => $image->getMimeType(),
 127                         'srcPath' => $image->getPath(),
 128                         'dstPath' => $dstPath,
 129                         'dstUrl' => $dstUrl,
 130                 );
 131
 132                 wfDebug( __METHOD__ . ": creating {$scalerParams['physicalDimensions']} thumbnail at $dstPath\n" );
 133
 134                 if ( !$image->mustRender() &&
 135                                 $scalerParams['physicalWidth'] == $scalerParams['srcWidth']
 136                                 && $scalerParams['physicalHeight'] == $scalerParams['srcHeight'] ) {
 137
 138                         # normaliseParams (or the user) wants us to return the unscaled image
 139                         wfDebug( __METHOD__ . ": returning unscaled image\n" );
 140                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 141                 }
 142
 143                 # Determine scaler type
 144                 $scaler = self::getScalerType( $dstPath );
 145                 wfDebug( __METHOD__ . ": scaler $scaler\n" );
 146
 147                 if ( $scaler == 'client' ) {
 148                         # Client-side image scaling, use the source URL
 149                         # Using the destination URL in a TRANSFORM_LATER request would be incorrect
 150                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 151                 }
 152
 153                 if ( $flags & self::TRANSFORM_LATER ) {
 154                         wfDebug( __METHOD__ . ": Transforming later per flags.\n" );
 155                         return new ThumbnailImage( $image, $dstUrl, $scalerParams['clientWidth'],
 156                                 $scalerParams['clientHeight'], $dstPath );
 157                 }
 158
 159                 # Try to make a target path for the thumbnail
 160                 if ( !wfMkdirParents( dirname( $dstPath ), null, __METHOD__ ) ) {
 161                         wfDebug( __METHOD__ . ": Unable to create thumbnail destination directory, falling back to client scaling\n" );
 162                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 163                 }
 164
 165                 # Try a hook
 166                 $mto = null;
 167                 wfRunHooks( 'BitmapHandlerTransform', array( $this, $image, &$scalerParams, &$mto ) );
 168                 if ( !is_null( $mto ) ) {
 169                         wfDebug( __METHOD__ . ": Hook to BitmapHandlerTransform created an mto\n" );
 170                         $scaler = 'hookaborted';
 171                 }
 172
 173                 switch ( $scaler ) {
 174                         case 'hookaborted':
 175                                 # Handled by the hook above
 176                                 $err = $mto->isError() ? $mto : false;
 177                                 break;
 178                         case 'im':
 179                                 $err = $this->transformImageMagick( $image, $scalerParams );
 180                                 break;
 181                         case 'custom':
 182                                 $err = $this->transformCustom( $image, $scalerParams );
 183                                 break;
 184                         case 'imext':
 185                                 $err = $this->transformImageMagickExt( $image, $scalerParams );
 186                                 break;
 187                         case 'gd':
 188                         default:
 189                                 $err = $this->transformGd( $image, $scalerParams );
 190                                 break;
 191                 }
 192
 193                 # Remove the file if a zero-byte thumbnail was created, or if there was an error
 194                 $removed = $this->removeBadFile( $dstPath, (bool)$err );
 195                 if ( $err ) {
 196                         # transform returned MediaTransforError
 197                         return $err;
 198                 } elseif ( $removed ) {
 199                         # Thumbnail was zero-byte and had to be removed
 200                         return new MediaTransformError( 'thumbnail_error',
 201                                 $scalerParams['clientWidth'], $scalerParams['clientHeight'] );
 202                 } elseif ( $mto ) {
 203                         return $mto;
 204                 } else {
 205                         return new ThumbnailImage( $image, $dstUrl, $scalerParams['clientWidth'],
 206                                 $scalerParams['clientHeight'], $dstPath );
 207                 }
 208         }
 209
 210         /**
 211          * Returns which scaler type should be used. Creates parent directories
 212          * for $dstPath and returns 'client' on error
 213          *
 214          * @return string client,im,custom,gd
 215          */
 216         protected static function getScalerType( $dstPath, $checkDstPath = true ) {
 217                 global $wgUseImageResize, $wgUseImageMagick, $wgCustomConvertCommand;
 218
 219                 if ( !$dstPath && $checkDstPath ) {
 220                         # No output path available, client side scaling only
 221                         $scaler = 'client';
 222                 } elseif ( !$wgUseImageResize ) {
 223                         $scaler = 'client';
 224                 } elseif ( $wgUseImageMagick ) {
 225                         $scaler = 'im';
 226                 } elseif ( $wgCustomConvertCommand ) {
 227                         $scaler = 'custom';
 228                 } elseif ( function_exists( 'imagecreatetruecolor' ) ) {
 229                         $scaler = 'gd';
 230                 } elseif ( class_exists( 'Imagick' ) ) {
 231                         $scaler = 'imext';
 232                 } else {
 233                         $scaler = 'client';
 234                 }
 235
 236                 if ( $scaler != 'client' && $dstPath ) {
 237                         if ( !wfMkdirParents( dirname( $dstPath ), null, __METHOD__ ) ) {
 238                                 # Unable to create a path for the thumbnail
 239                                 return 'client';
 240                         }
 241                 }
 242                 return $scaler;
 243         }
 244
 245         /**
 246          * Get a ThumbnailImage that respresents an image that will be scaled
 247          * client side
 248          *
 249          * @param $image File File associated with this thumbnail
 250          * @param $params array Array with scaler params
 251          * @return ThumbnailImage
 252          */
 253         protected function getClientScalingThumbnailImage( $image, $params ) {
 254                 return new ThumbnailImage( $image, $image->getURL(),
 255                                 $params['clientWidth'], $params['clientHeight'], $params['srcPath'] );
 256         }
 257
 258         /**
 259          * Transform an image using ImageMagick
 260          *
 261          * @param $image File File associated with this thumbnail
 262          * @param $params array Array with scaler params
 263          *
 264          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 265          */
 266         protected function transformImageMagick( $image, $params ) {
 267                 # use ImageMagick
 268                 global $wgSharpenReductionThreshold, $wgSharpenParameter,
 269                         $wgMaxAnimatedGifArea,
 270                         $wgImageMagickTempDir, $wgImageMagickConvertCommand;
 271
 272                 $quality = '';
 273                 $sharpen = '';
 274                 $scene = false;
 275                 $animation_pre = '';
 276                 $animation_post = '';
 277                 $decoderHint = '';
 278                 if ( $params['mimeType'] == 'image/jpeg' ) {
 279                         $quality = "-quality 80"; // 80%
 280                         # Sharpening, see bug 6193
 281                         if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 282                                         / ( $params['srcWidth'] + $params['srcHeight'] )
 283                                         < $wgSharpenReductionThreshold ) {
 284                                 $sharpen = "-sharpen " . wfEscapeShellArg( $wgSharpenParameter );
 285                         }
 286                         // JPEG decoder hint to reduce memory, available since IM 6.5.6-2
 287                         $decoderHint = "-define jpeg:size={$params['physicalDimensions']}";
 288
 289                 } elseif ( $params['mimeType'] == 'image/png' ) {
 290                         $quality = "-quality 95"; // zlib 9, adaptive filtering
 291
 292                 } elseif ( $params['mimeType'] == 'image/gif' ) {
 293                         if ( $this->getImageArea( $image, $params['srcWidth'],
 294                                         $params['srcHeight'] ) > $wgMaxAnimatedGifArea ) {
 295                                 // Extract initial frame only; we're so big it'll
 296                                 // be a total drag. :P
 297                                 $scene = 0;
 298
 299                         } elseif ( $this->isAnimatedImage( $image ) ) {
 300                                 // Coalesce is needed to scale animated GIFs properly (bug 1017).
 301                                 $animation_pre = '-coalesce';
 302                                 // We optimize the output, but -optimize is broken,
 303                                 // use optimizeTransparency instead (bug 11822)
 304                                 if ( version_compare( $this->getMagickVersion(), "6.3.5" ) >= 0 ) {
 305                                         $animation_post = '-fuzz 5% -layers optimizeTransparency';
 306                                 }
 307                         }
 308                 }
 309
 310                 // Use one thread only, to avoid deadlock bugs on OOM
 311                 $env = array( 'OMP_NUM_THREADS' => 1 );
 312                 if ( strval( $wgImageMagickTempDir ) !== '' ) {
 313                         $env['MAGICK_TMPDIR'] = $wgImageMagickTempDir;
 314                 }
 315
 316                 $rotation = $this->getRotation( $image );
 317                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 318
 319                 $cmd  =
 320                         wfEscapeShellArg( $wgImageMagickConvertCommand ) .
 321                         // Specify white background color, will be used for transparent images
 322                         // in Internet Explorer/Windows instead of default black.
 323                         " {$quality} -background white" .
 324                         " {$decoderHint} " .
 325                         wfEscapeShellArg( $this->escapeMagickInput( $params['srcPath'], $scene ) ) .
 326                         " {$animation_pre}" .
 327                         // For the -thumbnail option a "!" is needed to force exact size,
 328                         // or ImageMagick may decide your ratio is wrong and slice off
 329                         // a pixel.
 330                         " -thumbnail " . wfEscapeShellArg( "{$width}x{$height}!" ) .
 331                         // Add the source url as a comment to the thumb, but don't add the flag if there's no comment
 332                         ( $params['comment'] !== ''
 333                                 ? " -set comment " . wfEscapeShellArg( $this->escapeMagickProperty( $params['comment'] ) )
 334                                 : '' ) .
 335                         " -depth 8 $sharpen -auto-orient" .
 336                         " {$animation_post} " .
 337                         wfEscapeShellArg( $this->escapeMagickOutput( $params['dstPath'] ) ) . " 2>&1";
 338
 339                 wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
 340                 wfProfileIn( 'convert' );
 341                 $retval = 0;
 342                 $err = wfShellExec( $cmd, $retval, $env );
 343                 wfProfileOut( 'convert' );
 344
 345                 if ( $retval !== 0 ) {
 346                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 347                         return $this->getMediaTransformError( $params, $err );
 348                 }
 349
 350                 return false; # No error
 351         }
 352
 353         /**
 354          * Transform an image using the Imagick PHP extension
 355          *
 356          * @param $image File File associated with this thumbnail
 357          * @param $params array Array with scaler params
 358          *
 359          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 360          */
 361         protected function transformImageMagickExt( $image, $params ) {
 362                 global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea;
 363
 364                 try {
 365                         $im = new Imagick();
 366                         $im->readImage( $params['srcPath'] );
 367
 368                         if ( $params['mimeType'] == 'image/jpeg' ) {
 369                                 // Sharpening, see bug 6193
 370                                 if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 371                                                 / ( $params['srcWidth'] + $params['srcHeight'] )
 372                                                 < $wgSharpenReductionThreshold ) {
 373                                         // Hack, since $wgSharpenParamater is written specifically for the command line convert
 374                                         list( $radius, $sigma ) = explode( 'x', $wgSharpenParameter );
 375                                         $im->sharpenImage( $radius, $sigma );
 376                                 }
 377                                 $im->setCompressionQuality( 80 );
 378                         } elseif( $params['mimeType'] == 'image/png' ) {
 379                                 $im->setCompressionQuality( 95 );
 380                         } elseif ( $params['mimeType'] == 'image/gif' ) {
 381                                 if ( $this->getImageArea( $image, $params['srcWidth'],
 382                                                 $params['srcHeight'] ) > $wgMaxAnimatedGifArea ) {
 383                                         // Extract initial frame only; we're so big it'll
 384                                         // be a total drag. :P
 385                                         $im->setImageScene( 0 );
 386                                 } elseif ( $this->isAnimatedImage( $image ) ) {
 387                                         // Coalesce is needed to scale animated GIFs properly (bug 1017).
 388                                         $im = $im->coalesceImages();
 389                                 }
 390                         }
 391
 392                         $rotation = $this->getRotation( $image );
 393                         list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 394
 395                         $im->setImageBackgroundColor( new ImagickPixel( 'white' ) );
 396
 397                         // Call Imagick::thumbnailImage on each frame
 398                         foreach ( $im as $i => $frame ) {
 399                                 if ( !$frame->thumbnailImage( $width, $height, /* fit */ false ) ) {
 400                                         return $this->getMediaTransformError( $params, "Error scaling frame $i" );
 401                                 }
 402                         }
 403                         $im->setImageDepth( 8 );
 404
 405                         if ( $rotation ) {
 406                                 if ( !$im->rotateImage( new ImagickPixel( 'white' ), 360 - $rotation ) ) {
 407                                         return $this->getMediaTransformError( $params, "Error rotating $rotation degrees" );
 408                                 }
 409                         }
 410
 411                         if ( $this->isAnimatedImage( $image ) ) {
 412                                 wfDebug( __METHOD__ . ": Writing animated thumbnail\n" );
 413                                 // This is broken somehow... can't find out how to fix it
 414                                 $result = $im->writeImages( $params['dstPath'], true );
 415                         } else {
 416                                 $result = $im->writeImage( $params['dstPath'] );
 417                         }
 418                         if ( !$result ) {
 419                                 return $this->getMediaTransformError( $params,
 420                                         "Unable to write thumbnail to {$params['dstPath']}" );
 421                         }
 422
 423                 } catch ( ImagickException $e ) {
 424                         return $this->getMediaTransformError( $params, $e->getMessage() );
 425                 }
 426
 427                 return false;
 428
 429         }
 430
 431         /**
 432          * Transform an image using a custom command
 433          *
 434          * @param $image File File associated with this thumbnail
 435          * @param $params array Array with scaler params
 436          *
 437          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 438          */
 439         protected function transformCustom( $image, $params ) {
 440                 # Use a custom convert command
 441                 global $wgCustomConvertCommand;
 442
 443                 # Variables: %s %d %w %h
 444                 $src = wfEscapeShellArg( $params['srcPath'] );
 445                 $dst = wfEscapeShellArg( $params['dstPath'] );
 446                 $cmd = $wgCustomConvertCommand;
 447                 $cmd = str_replace( '%s', $src, str_replace( '%d', $dst, $cmd ) ); # Filenames
 448                 $cmd = str_replace( '%h', $params['physicalHeight'],
 449                         str_replace( '%w', $params['physicalWidth'], $cmd ) ); # Size
 450                 wfDebug( __METHOD__ . ": Running custom convert command $cmd\n" );
 451                 wfProfileIn( 'convert' );
 452                 $retval = 0;
 453                 $err = wfShellExec( $cmd, $retval );
 454                 wfProfileOut( 'convert' );
 455
 456                 if ( $retval !== 0 ) {
 457                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 458                         return $this->getMediaTransformError( $params, $err );
 459                 }
 460                 return false; # No error
 461         }
 462
 463         /**
 464          * Log an error that occured in an external process
 465          *
 466          * @param $retval int
 467          * @param $err int
 468          * @param $cmd string
 469          */
 470         protected function logErrorForExternalProcess( $retval, $err, $cmd ) {
 471                 wfDebugLog( 'thumbnail',
 472                         sprintf( 'thumbnail failed on %s: error %d "%s" from "%s"',
 473                                         wfHostname(), $retval, trim( $err ), $cmd ) );
 474         }
 475         /**
 476          * Get a MediaTransformError with error 'thumbnail_error'
 477          *
 478          * @param $params array Parameter array as passed to the transform* functions
 479          * @param $errMsg string Error message
 480          * @return MediaTransformError
 481          */
 482         public function getMediaTransformError( $params, $errMsg ) {
 483                 return new MediaTransformError( 'thumbnail_error', $params['clientWidth'],
 484                                         $params['clientHeight'], $errMsg );
 485         }
 486
 487         /**
 488          * Transform an image using the built in GD library
 489          *
 490          * @param $image File File associated with this thumbnail
 491          * @param $params array Array with scaler params
 492          *
 493          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 494          */
 495         protected function transformGd( $image, $params ) {
 496                 # Use PHP's builtin GD library functions.
 497                 #
 498                 # First find out what kind of file this is, and select the correct
 499                 # input routine for this.
 500
 501                 $typemap = array(
 502                         'image/gif'          => array( 'imagecreatefromgif',  'palette',   'imagegif'  ),
 503                         'image/jpeg'         => array( 'imagecreatefromjpeg', 'truecolor', array( __CLASS__, 'imageJpegWrapper' ) ),
 504                         'image/png'          => array( 'imagecreatefrompng',  'bits',      'imagepng'  ),
 505                         'image/vnd.wap.wbmp' => array( 'imagecreatefromwbmp', 'palette',   'imagewbmp'  ),
 506                         'image/xbm'          => array( 'imagecreatefromxbm',  'palette',   'imagexbm'  ),
 507                 );
 508                 if ( !isset( $typemap[$params['mimeType']] ) ) {
 509                         $err = 'Image type not supported';
 510                         wfDebug( "$err\n" );
 511                         $errMsg = wfMsg ( 'thumbnail_image-type' );
 512                         return $this->getMediaTransformError( $params, $errMsg );
 513                 }
 514                 list( $loader, $colorStyle, $saveType ) = $typemap[$params['mimeType']];
 515
 516                 if ( !function_exists( $loader ) ) {
 517                         $err = "Incomplete GD library configuration: missing function $loader";
 518                         wfDebug( "$err\n" );
 519                         $errMsg = wfMsg ( 'thumbnail_gd-library', $loader );
 520                         return $this->getMediaTransformError( $params, $errMsg );
 521                 }
 522
 523                 if ( !file_exists( $params['srcPath'] ) ) {
 524                         $err = "File seems to be missing: {$params['srcPath']}";
 525                         wfDebug( "$err\n" );
 526                         $errMsg = wfMsg ( 'thumbnail_image-missing', $params['srcPath'] );
 527                         return $this->getMediaTransformError( $params, $errMsg );
 528                 }
 529
 530                 $src_image = call_user_func( $loader, $params['srcPath'] );
 531
 532                 $rotation = function_exists( 'imagerotate' ) ? $this->getRotation( $image ) : 0;
 533                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 534                 $dst_image = imagecreatetruecolor( $width, $height );
 535
 536                 // Initialise the destination image to transparent instead of
 537                 // the default solid black, to support PNG and GIF transparency nicely
 538                 $background = imagecolorallocate( $dst_image, 0, 0, 0 );
 539                 imagecolortransparent( $dst_image, $background );
 540                 imagealphablending( $dst_image, false );
 541
 542                 if ( $colorStyle == 'palette' ) {
 543                         // Don't resample for paletted GIF images.
 544                         // It may just uglify them, and completely breaks transparency.
 545                         imagecopyresized( $dst_image, $src_image,
 546                                 0, 0, 0, 0,
 547                                 $width, $height,
 548                                 imagesx( $src_image ), imagesy( $src_image ) );
 549                 } else {
 550                         imagecopyresampled( $dst_image, $src_image,
 551                                 0, 0, 0, 0,
 552                                 $width, $height,
 553                                 imagesx( $src_image ), imagesy( $src_image ) );
 554                 }
 555
 556                 if ( $rotation % 360 != 0 && $rotation % 90 == 0 ) {
 557                         $rot_image = imagerotate( $dst_image, $rotation, 0 );
 558                         imagedestroy( $dst_image );
 559                         $dst_image = $rot_image;
 560                 }
 561
 562                 imagesavealpha( $dst_image, true );
 563
 564                 call_user_func( $saveType, $dst_image, $params['dstPath'] );
 565                 imagedestroy( $dst_image );
 566                 imagedestroy( $src_image );
 567
 568                 return false; # No error
 569         }
 570
 571         /**
 572          * Escape a string for ImageMagick's property input (e.g. -set -comment)
 573          * See InterpretImageProperties() in magick/property.c
 574          */
 575         function escapeMagickProperty( $s ) {
 576                 // Double the backslashes
 577                 $s = str_replace( '\\', '\\\\', $s );
 578                 // Double the percents
 579                 $s = str_replace( '%', '%%', $s );
 580                 // Escape initial - or @
 581                 if ( strlen( $s ) > 0 && ( $s[0] === '-' || $s[0] === '@' ) ) {
 582                         $s = '\\' . $s;
 583                 }
 584                 return $s;
 585         }
 586
 587         /**
 588          * Escape a string for ImageMagick's input filenames. See ExpandFilenames()
 589          * and GetPathComponent() in magick/utility.c.
 590          *
 591          * This won't work with an initial ~ or @, so input files should be prefixed
 592          * with the directory name.
 593          *
 594          * Glob character unescaping is broken in ImageMagick before 6.6.1-5, but
 595          * it's broken in a way that doesn't involve trying to convert every file
 596          * in a directory, so we're better off escaping and waiting for the bugfix
 597          * to filter down to users.
 598          *
 599          * @param $path string The file path
 600          * @param $scene string The scene specification, or false if there is none
 601          */
 602         function escapeMagickInput( $path, $scene = false ) {
 603                 # Die on initial metacharacters (caller should prepend path)
 604                 $firstChar = substr( $path, 0, 1 );
 605                 if ( $firstChar === '~' || $firstChar === '@' ) {
 606                         throw new MWException( __METHOD__ . ': cannot escape this path name' );
 607                 }
 608
 609                 # Escape glob chars
 610                 $path = preg_replace( '/[*?\[\]{}]/', '\\\\\0', $path );
 611
 612                 return $this->escapeMagickPath( $path, $scene );
 613         }
 614
 615         /**
 616          * Escape a string for ImageMagick's output filename. See
 617          * InterpretImageFilename() in magick/image.c.
 618          */
 619         function escapeMagickOutput( $path, $scene = false ) {
 620                 $path = str_replace( '%', '%%', $path );
 621                 return $this->escapeMagickPath( $path, $scene );
 622         }
 623
 624         /**
 625          * Armour a string against ImageMagick's GetPathComponent(). This is a
 626          * helper function for escapeMagickInput() and escapeMagickOutput().
 627          *
 628          * @param $path string The file path
 629          * @param $scene string The scene specification, or false if there is none
 630          */
 631         protected function escapeMagickPath( $path, $scene = false ) {
 632                 # Die on format specifiers (other than drive letters). The regex is
 633                 # meant to match all the formats you get from "convert -list format"
 634                 if ( preg_match( '/^([a-zA-Z0-9-]+):/', $path, $m ) ) {
 635                         if ( wfIsWindows() && is_dir( $m[0] ) ) {
 636                                 // OK, it's a drive letter
 637                                 // ImageMagick has a similar exception, see IsMagickConflict()
 638                         } else {
 639                                 throw new MWException( __METHOD__ . ': unexpected colon character in path name' );
 640                         }
 641                 }
 642
 643                 # If there are square brackets, add a do-nothing scene specification
 644                 # to force a literal interpretation
 645                 if ( $scene === false ) {
 646                         if ( strpos( $path, '[' ) !== false ) {
 647                                 $path .= '[0--1]';
 648                         }
 649                 } else {
 650                         $path .= "[$scene]";
 651                 }
 652                 return $path;
 653         }
 654
 655         /**
 656          * Retrieve the version of the installed ImageMagick
 657          * You can use PHPs version_compare() to use this value
 658          * Value is cached for one hour.
 659          * @return String representing the IM version.
 660          */
 661         protected function getMagickVersion() {
 662                 global $wgMemc;
 663
 664                 $cache = $wgMemc->get( "imagemagick-version" );
 665                 if ( !$cache ) {
 666                         global $wgImageMagickConvertCommand;
 667                         $cmd = wfEscapeShellArg( $wgImageMagickConvertCommand ) . ' -version';
 668                         wfDebug( __METHOD__ . ": Running convert -version\n" );
 669                         $retval = '';
 670                         $return = wfShellExec( $cmd, $retval );
 671                         $x = preg_match( '/Version: ImageMagick ([0-9]*\.[0-9]*\.[0-9]*)/', $return, $matches );
 672                         if ( $x != 1 ) {
 673                                 wfDebug( __METHOD__ . ": ImageMagick version check failed\n" );
 674                                 return null;
 675                         }
 676                         $wgMemc->set( "imagemagick-version", $matches[1], 3600 );
 677                         return $matches[1];
 678                 }
 679                 return $cache;
 680         }
 681
 682         static function imageJpegWrapper( $dst_image, $thumbPath ) {
 683                 imageinterlace( $dst_image );
 684                 imagejpeg( $dst_image, $thumbPath, 95 );
 685         }
 686
 687         /**
 688          * Try to read out the orientation of the file and return the angle that
 689          * the file needs to be rotated to be viewed
 690          *
 691          * @param $file File
 692          * @return int 0, 90, 180 or 270
 693          */
 694         public function getRotation( $file ) {
 695                 $data = $file->getMetadata();
 696                 if ( !$data ) {
 697                         return 0;
 698                 }
 699                 wfSuppressWarnings();
 700                 $data = unserialize( $data );
 701                 wfRestoreWarnings();
 702                 if ( isset( $data['Orientation'] ) ) {
 703                         # See http://sylvana.net/jpegcrop/exif_orientation.html
 704                         switch ( $data['Orientation'] ) {
 705                                 case 8:
 706                                         return 90;
 707                                 case 3:
 708                                         return 180;
 709                                 case 6:
 710                                         return 270;
 711                                 default:
 712                                         return 0;
 713                         }
 714                 }
 715                 return 0;
 716         }
 717
 718         /**
 719          * Returns whether the current scaler supports rotation (im and gd do)
 720          *
 721          * @return bool
 722          */
 723         public static function canRotate() {
 724                 $scaler = self::getScalerType( null, false );
 725                 switch ( $scaler ) {
 726                         case 'im':
 727                                 # ImageMagick supports autorotation
 728                                 return true;
 729                         case 'imext':
 730                                 # Imagick::rotateImage
 731                                 return true;
 732                         case 'gd':
 733                                 # GD's imagerotate function is used to rotate images, but not
 734                                 # all precompiled PHP versions have that function
 735                                 return function_exists( 'imagerotate' );
 736                         default:
 737                                 # Other scalers don't support rotation
 738                                 return false;
 739                 }
 740         }
 741
 742         /**
 743          * Rerurns whether the file needs to be rendered. Returns true if the
 744          * file requires rotation and we are able to rotate it.
 745          *
 746          * @param $file File
 747          * @return bool
 748          */
 749         public function mustRender( $file ) {
 750                 return self::canRotate() && $this->getRotation( $file ) != 0;
 751         }
 752 }