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 array Transform parameters. Entries with the keys 'width'
  19          * and 'height' are the respective screen width and height, while the keys
  20          * 'physicalWidth' and 'physicalHeight' indicate the thumbnail dimensions.
  21          * @return bool
  22          */
  23         function normaliseParams( $image, &$params ) {
  24
  25                 if ( !parent::normaliseParams( $image, $params ) ) {
  26                         return false;
  27                 }
  28
  29                 $mimeType = $image->getMimeType();
  30                 # Obtain the source, pre-rotation dimensions
  31                 $srcWidth = $image->getWidth( $params['page'] );
  32                 $srcHeight = $image->getHeight( $params['page'] );
  33
  34                 # Don't make an image bigger than the source
  35                 if ( $params['physicalWidth'] >= $srcWidth ) {
  36                         $params['physicalWidth'] = $srcWidth;
  37                         $params['physicalHeight'] = $srcHeight;
  38
  39                         # Skip scaling limit checks if no scaling is required
  40                         # due to requested size being bigger than source.
  41                         if ( !$image->mustRender() ) {
  42                                 return true;
  43                         }
  44                 }
  45
  46                 return true;
  47         }
  48
  49         /**
  50          * Check if the file is smaller than the maximum image area for
  51          * thumbnailing. Check will always pass if the scaler is 'hookaborted' or
  52          * if the scaler is 'im' and the mime type is 'image/jpeg'
  53          *
  54          * @param File $image
  55          * @param string $scaler
  56          */
  57         function checkImageArea( $image, $scaler ) {
  58                 global $wgMaxImageArea;
  59                 # Don't thumbnail an image so big that it will fill hard drives and send servers into swap
  60                 # JPEG has the handy property of allowing thumbnailing without full decompression, so we make
  61                 # an exception for it.
  62
  63
  64                 if ( $image->getMimeType() == 'image/jpeg' && $scaler == 'im' )
  65                 {
  66                         # ImageMagick can efficiently downsize jpg images without loading
  67                         # the entire file in memory
  68                         return true;
  69                 }
  70
  71                 if ( $scaler == 'hookaborted' )
  72                 {
  73                         # If a hook wants to transform the image, it is responsible for
  74                         # checking the image size, so abort here
  75                         return true;
  76                 }
  77
  78                 # Do the actual check
  79                 return $this->getImageArea( $image, $image->getWidth(), $image->getHeight() ) <= $wgMaxImageArea;
  80         }
  81
  82
  83         /**
  84          * Extracts the width/height if the image will be scaled before rotating
  85          *
  86          * This will match the physical size/aspect ratio of the original image
  87          * prior to application of the rotation -- so for a portrait image that's
  88          * stored as raw landscape with 90-degress rotation, the resulting size
  89          * will be wider than it is tall.
  90          *
  91          * @param $params array Parameters as returned by normaliseParams
  92          * @param $rotation int The rotation angle that will be applied
  93          * @return array ($width, $height) array
  94          */
  95         public function extractPreRotationDimensions( $params, $rotation ) {
  96                 if ( $rotation == 90 || $rotation == 270 ) {
  97                         # We'll resize before rotation, so swap the dimensions again
  98                         $width = $params['physicalHeight'];
  99                         $height = $params['physicalWidth'];
 100                 } else {
 101                         $width = $params['physicalWidth'];
 102                         $height = $params['physicalHeight'];
 103                 }
 104                 return array( $width, $height );
 105         }
 106
 107
 108         // Function that returns the number of pixels to be thumbnailed.
 109         // Intended for animated GIFs to multiply by the number of frames.
 110         function getImageArea( $image, $width, $height ) {
 111                 return $width * $height;
 112         }
 113
 114         /**
 115          * @param $image File
 116          * @param  $dstPath
 117          * @param  $dstUrl
 118          * @param  $params
 119          * @param int $flags
 120          * @return MediaTransformError|ThumbnailImage|TransformParameterError
 121          */
 122         function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
 123                 if ( !$this->normaliseParams( $image, $params ) ) {
 124                         return new TransformParameterError( $params );
 125                 }
 126                 # Create a parameter array to pass to the scaler
 127                 $scalerParams = array(
 128                         # The size to which the image will be resized
 129                         'physicalWidth' => $params['physicalWidth'],
 130                         'physicalHeight' => $params['physicalHeight'],
 131                         'physicalDimensions' => "{$params['physicalWidth']}x{$params['physicalHeight']}",
 132                         # The size of the image on the page
 133                         'clientWidth' => $params['width'],
 134                         'clientHeight' => $params['height'],
 135                         # Comment as will be added to the EXIF of the thumbnail
 136                         'comment' => isset( $params['descriptionUrl'] ) ?
 137                                 "File source: {$params['descriptionUrl']}" : '',
 138                         # Properties of the original image
 139                         'srcWidth' => $image->getWidth(),
 140                         'srcHeight' => $image->getHeight(),
 141                         'mimeType' => $image->getMimeType(),
 142                         'srcPath' => $image->getPath(),
 143                         'dstPath' => $dstPath,
 144                         'dstUrl' => $dstUrl,
 145                 );
 146
 147                 wfDebug( __METHOD__ . ": creating {$scalerParams['physicalDimensions']} thumbnail at $dstPath\n" );
 148
 149                 if ( !$image->mustRender() &&
 150                                 $scalerParams['physicalWidth'] == $scalerParams['srcWidth']
 151                                 && $scalerParams['physicalHeight'] == $scalerParams['srcHeight'] ) {
 152
 153                         # normaliseParams (or the user) wants us to return the unscaled image
 154                         wfDebug( __METHOD__ . ": returning unscaled image\n" );
 155                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 156                 }
 157
 158                 # Determine scaler type
 159                 $scaler = self::getScalerType( $dstPath );
 160                 wfDebug( __METHOD__ . ": scaler $scaler\n" );
 161
 162                 if ( $scaler == 'client' ) {
 163                         # Client-side image scaling, use the source URL
 164                         # Using the destination URL in a TRANSFORM_LATER request would be incorrect
 165                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 166                 }
 167
 168                 if ( $flags & self::TRANSFORM_LATER ) {
 169                         wfDebug( __METHOD__ . ": Transforming later per flags.\n" );
 170                         return new ThumbnailImage( $image, $dstUrl, $scalerParams['clientWidth'],
 171                                 $scalerParams['clientHeight'], $dstPath );
 172                 }
 173
 174                 # Try to make a target path for the thumbnail
 175                 if ( !wfMkdirParents( dirname( $dstPath ), null, __METHOD__ ) ) {
 176                         wfDebug( __METHOD__ . ": Unable to create thumbnail destination directory, falling back to client scaling\n" );
 177                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 178                 }
 179
 180                 # Try a hook
 181                 $mto = null;
 182                 wfRunHooks( 'BitmapHandlerTransform', array( $this, $image, &$scalerParams, &$mto ) );
 183                 if ( !is_null( $mto ) ) {
 184                         wfDebug( __METHOD__ . ": Hook to BitmapHandlerTransform created an mto\n" );
 185                         $scaler = 'hookaborted';
 186                 }
 187
 188                 # Check max image area
 189                 if ( !$this->checkImageArea( $image, $scaler ) )
 190                 {
 191                         return new TransformParameterError( $params );
 192                 }
 193
 194                 switch ( $scaler ) {
 195                         case 'hookaborted':
 196                                 # Handled by the hook above
 197                                 $err = $mto->isError() ? $mto : false;
 198                                 break;
 199                         case 'im':
 200                                 $err = $this->transformImageMagick( $image, $scalerParams );
 201                                 break;
 202                         case 'custom':
 203                                 $err = $this->transformCustom( $image, $scalerParams );
 204                                 break;
 205                         case 'imext':
 206                                 $err = $this->transformImageMagickExt( $image, $scalerParams );
 207                                 break;
 208                         case 'gd':
 209                         default:
 210                                 $err = $this->transformGd( $image, $scalerParams );
 211                                 break;
 212                 }
 213
 214                 # Remove the file if a zero-byte thumbnail was created, or if there was an error
 215                 $removed = $this->removeBadFile( $dstPath, (bool)$err );
 216                 if ( $err ) {
 217                         # transform returned MediaTransforError
 218                         return $err;
 219                 } elseif ( $removed ) {
 220                         # Thumbnail was zero-byte and had to be removed
 221                         return new MediaTransformError( 'thumbnail_error',
 222                                 $scalerParams['clientWidth'], $scalerParams['clientHeight'] );
 223                 } elseif ( $mto ) {
 224                         return $mto;
 225                 } else {
 226                         return new ThumbnailImage( $image, $dstUrl, $scalerParams['clientWidth'],
 227                                 $scalerParams['clientHeight'], $dstPath );
 228                 }
 229         }
 230
 231         /**
 232          * Returns which scaler type should be used. Creates parent directories
 233          * for $dstPath and returns 'client' on error
 234          *
 235          * @return string client,im,custom,gd
 236          */
 237         protected static function getScalerType( $dstPath, $checkDstPath = true ) {
 238                 global $wgUseImageResize, $wgUseImageMagick, $wgCustomConvertCommand;
 239
 240                 if ( !$dstPath && $checkDstPath ) {
 241                         # No output path available, client side scaling only
 242                         $scaler = 'client';
 243                 } elseif ( !$wgUseImageResize ) {
 244                         $scaler = 'client';
 245                 } elseif ( $wgUseImageMagick ) {
 246                         $scaler = 'im';
 247                 } elseif ( $wgCustomConvertCommand ) {
 248                         $scaler = 'custom';
 249                 } elseif ( function_exists( 'imagecreatetruecolor' ) ) {
 250                         $scaler = 'gd';
 251                 } elseif ( class_exists( 'Imagick' ) ) {
 252                         $scaler = 'imext';
 253                 } else {
 254                         $scaler = 'client';
 255                 }
 256                 return $scaler;
 257         }
 258
 259         /**
 260          * Get a ThumbnailImage that respresents an image that will be scaled
 261          * client side
 262          *
 263          * @param $image File File associated with this thumbnail
 264          * @param $params array Array with scaler params
 265          * @return ThumbnailImage
 266          *
 267          * @fixme no rotation support
 268          */
 269         protected function getClientScalingThumbnailImage( $image, $params ) {
 270                 return new ThumbnailImage( $image, $image->getURL(),
 271                                 $params['clientWidth'], $params['clientHeight'], $params['srcPath'] );
 272         }
 273
 274         /**
 275          * Transform an image using ImageMagick
 276          *
 277          * @param $image File File associated with this thumbnail
 278          * @param $params array Array with scaler params
 279          *
 280          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 281          */
 282         protected function transformImageMagick( $image, $params ) {
 283                 # use ImageMagick
 284                 global $wgSharpenReductionThreshold, $wgSharpenParameter,
 285                         $wgMaxAnimatedGifArea,
 286                         $wgImageMagickTempDir, $wgImageMagickConvertCommand;
 287
 288                 $quality = '';
 289                 $sharpen = '';
 290                 $scene = false;
 291                 $animation_pre = '';
 292                 $animation_post = '';
 293                 $decoderHint = '';
 294                 if ( $params['mimeType'] == 'image/jpeg' ) {
 295                         $quality = "-quality 80"; // 80%
 296                         # Sharpening, see bug 6193
 297                         if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 298                                         / ( $params['srcWidth'] + $params['srcHeight'] )
 299                                         < $wgSharpenReductionThreshold ) {
 300                                 $sharpen = "-sharpen " . wfEscapeShellArg( $wgSharpenParameter );
 301                         }
 302                         // JPEG decoder hint to reduce memory, available since IM 6.5.6-2
 303                         $decoderHint = "-define jpeg:size={$params['physicalDimensions']}";
 304
 305                 } elseif ( $params['mimeType'] == 'image/png' ) {
 306                         $quality = "-quality 95"; // zlib 9, adaptive filtering
 307
 308                 } elseif ( $params['mimeType'] == 'image/gif' ) {
 309                         if ( $this->getImageArea( $image, $params['srcWidth'],
 310                                         $params['srcHeight'] ) > $wgMaxAnimatedGifArea ) {
 311                                 // Extract initial frame only; we're so big it'll
 312                                 // be a total drag. :P
 313                                 $scene = 0;
 314
 315                         } elseif ( $this->isAnimatedImage( $image ) ) {
 316                                 // Coalesce is needed to scale animated GIFs properly (bug 1017).
 317                                 $animation_pre = '-coalesce';
 318                                 // We optimize the output, but -optimize is broken,
 319                                 // use optimizeTransparency instead (bug 11822)
 320                                 if ( version_compare( $this->getMagickVersion(), "6.3.5" ) >= 0 ) {
 321                                         $animation_post = '-fuzz 5% -layers optimizeTransparency';
 322                                 }
 323                         }
 324                 }
 325
 326                 // Use one thread only, to avoid deadlock bugs on OOM
 327                 $env = array( 'OMP_NUM_THREADS' => 1 );
 328                 if ( strval( $wgImageMagickTempDir ) !== '' ) {
 329                         $env['MAGICK_TMPDIR'] = $wgImageMagickTempDir;
 330                 }
 331
 332                 $rotation = $this->getRotation( $image );
 333                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 334
 335                 $cmd  =
 336                         wfEscapeShellArg( $wgImageMagickConvertCommand ) .
 337                         // Specify white background color, will be used for transparent images
 338                         // in Internet Explorer/Windows instead of default black.
 339                         " {$quality} -background white" .
 340                         " {$decoderHint} " .
 341                         wfEscapeShellArg( $this->escapeMagickInput( $params['srcPath'], $scene ) ) .
 342                         " {$animation_pre}" .
 343                         // For the -thumbnail option a "!" is needed to force exact size,
 344                         // or ImageMagick may decide your ratio is wrong and slice off
 345                         // a pixel.
 346                         " -thumbnail " . wfEscapeShellArg( "{$width}x{$height}!" ) .
 347                         // Add the source url as a comment to the thumb, but don't add the flag if there's no comment
 348                         ( $params['comment'] !== ''
 349                                 ? " -set comment " . wfEscapeShellArg( $this->escapeMagickProperty( $params['comment'] ) )
 350                                 : '' ) .
 351                         " -depth 8 $sharpen " .
 352                         " -rotate -$rotation " .
 353                         " {$animation_post} " .
 354                         wfEscapeShellArg( $this->escapeMagickOutput( $params['dstPath'] ) ) . " 2>&1";
 355
 356                 wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
 357                 wfProfileIn( 'convert' );
 358                 $retval = 0;
 359                 $err = wfShellExec( $cmd, $retval, $env );
 360                 wfProfileOut( 'convert' );
 361
 362                 if ( $retval !== 0 ) {
 363                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 364                         return $this->getMediaTransformError( $params, $err );
 365                 }
 366
 367                 return false; # No error
 368         }
 369
 370         /**
 371          * Transform an image using the Imagick PHP extension
 372          *
 373          * @param $image File File associated with this thumbnail
 374          * @param $params array Array with scaler params
 375          *
 376          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 377          */
 378         protected function transformImageMagickExt( $image, $params ) {
 379                 global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea;
 380
 381                 try {
 382                         $im = new Imagick();
 383                         $im->readImage( $params['srcPath'] );
 384
 385                         if ( $params['mimeType'] == 'image/jpeg' ) {
 386                                 // Sharpening, see bug 6193
 387                                 if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 388                                                 / ( $params['srcWidth'] + $params['srcHeight'] )
 389                                                 < $wgSharpenReductionThreshold ) {
 390                                         // Hack, since $wgSharpenParamater is written specifically for the command line convert
 391                                         list( $radius, $sigma ) = explode( 'x', $wgSharpenParameter );
 392                                         $im->sharpenImage( $radius, $sigma );
 393                                 }
 394                                 $im->setCompressionQuality( 80 );
 395                         } elseif( $params['mimeType'] == 'image/png' ) {
 396                                 $im->setCompressionQuality( 95 );
 397                         } elseif ( $params['mimeType'] == 'image/gif' ) {
 398                                 if ( $this->getImageArea( $image, $params['srcWidth'],
 399                                                 $params['srcHeight'] ) > $wgMaxAnimatedGifArea ) {
 400                                         // Extract initial frame only; we're so big it'll
 401                                         // be a total drag. :P
 402                                         $im->setImageScene( 0 );
 403                                 } elseif ( $this->isAnimatedImage( $image ) ) {
 404                                         // Coalesce is needed to scale animated GIFs properly (bug 1017).
 405                                         $im = $im->coalesceImages();
 406                                 }
 407                         }
 408
 409                         $rotation = $this->getRotation( $image );
 410                         list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 411
 412                         $im->setImageBackgroundColor( new ImagickPixel( 'white' ) );
 413
 414                         // Call Imagick::thumbnailImage on each frame
 415                         foreach ( $im as $i => $frame ) {
 416                                 if ( !$frame->thumbnailImage( $width, $height, /* fit */ false ) ) {
 417                                         return $this->getMediaTransformError( $params, "Error scaling frame $i" );
 418                                 }
 419                         }
 420                         $im->setImageDepth( 8 );
 421
 422                         if ( $rotation ) {
 423                                 if ( !$im->rotateImage( new ImagickPixel( 'white' ), 360 - $rotation ) ) {
 424                                         return $this->getMediaTransformError( $params, "Error rotating $rotation degrees" );
 425                                 }
 426                         }
 427
 428                         if ( $this->isAnimatedImage( $image ) ) {
 429                                 wfDebug( __METHOD__ . ": Writing animated thumbnail\n" );
 430                                 // This is broken somehow... can't find out how to fix it
 431                                 $result = $im->writeImages( $params['dstPath'], true );
 432                         } else {
 433                                 $result = $im->writeImage( $params['dstPath'] );
 434                         }
 435                         if ( !$result ) {
 436                                 return $this->getMediaTransformError( $params,
 437                                         "Unable to write thumbnail to {$params['dstPath']}" );
 438                         }
 439
 440                 } catch ( ImagickException $e ) {
 441                         return $this->getMediaTransformError( $params, $e->getMessage() );
 442                 }
 443
 444                 return false;
 445
 446         }
 447
 448         /**
 449          * Transform an image using a custom command
 450          *
 451          * @param $image File File associated with this thumbnail
 452          * @param $params array Array with scaler params
 453          *
 454          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 455          */
 456         protected function transformCustom( $image, $params ) {
 457                 # Use a custom convert command
 458                 global $wgCustomConvertCommand;
 459
 460                 # Variables: %s %d %w %h
 461                 $src = wfEscapeShellArg( $params['srcPath'] );
 462                 $dst = wfEscapeShellArg( $params['dstPath'] );
 463                 $cmd = $wgCustomConvertCommand;
 464                 $cmd = str_replace( '%s', $src, str_replace( '%d', $dst, $cmd ) ); # Filenames
 465                 $cmd = str_replace( '%h', $params['physicalHeight'],
 466                         str_replace( '%w', $params['physicalWidth'], $cmd ) ); # Size
 467                 wfDebug( __METHOD__ . ": Running custom convert command $cmd\n" );
 468                 wfProfileIn( 'convert' );
 469                 $retval = 0;
 470                 $err = wfShellExec( $cmd, $retval );
 471                 wfProfileOut( 'convert' );
 472
 473                 if ( $retval !== 0 ) {
 474                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 475                         return $this->getMediaTransformError( $params, $err );
 476                 }
 477                 return false; # No error
 478         }
 479
 480         /**
 481          * Log an error that occured in an external process
 482          *
 483          * @param $retval int
 484          * @param $err int
 485          * @param $cmd string
 486          */
 487         protected function logErrorForExternalProcess( $retval, $err, $cmd ) {
 488                 wfDebugLog( 'thumbnail',
 489                         sprintf( 'thumbnail failed on %s: error %d "%s" from "%s"',
 490                                         wfHostname(), $retval, trim( $err ), $cmd ) );
 491         }
 492         /**
 493          * Get a MediaTransformError with error 'thumbnail_error'
 494          *
 495          * @param $params array Parameter array as passed to the transform* functions
 496          * @param $errMsg string Error message
 497          * @return MediaTransformError
 498          */
 499         public function getMediaTransformError( $params, $errMsg ) {
 500                 return new MediaTransformError( 'thumbnail_error', $params['clientWidth'],
 501                                         $params['clientHeight'], $errMsg );
 502         }
 503
 504         /**
 505          * Transform an image using the built in GD library
 506          *
 507          * @param $image File File associated with this thumbnail
 508          * @param $params array Array with scaler params
 509          *
 510          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 511          */
 512         protected function transformGd( $image, $params ) {
 513                 # Use PHP's builtin GD library functions.
 514                 #
 515                 # First find out what kind of file this is, and select the correct
 516                 # input routine for this.
 517
 518                 $typemap = array(
 519                         'image/gif'          => array( 'imagecreatefromgif',  'palette',   'imagegif'  ),
 520                         'image/jpeg'         => array( 'imagecreatefromjpeg', 'truecolor', array( __CLASS__, 'imageJpegWrapper' ) ),
 521                         'image/png'          => array( 'imagecreatefrompng',  'bits',      'imagepng'  ),
 522                         'image/vnd.wap.wbmp' => array( 'imagecreatefromwbmp', 'palette',   'imagewbmp'  ),
 523                         'image/xbm'          => array( 'imagecreatefromxbm',  'palette',   'imagexbm'  ),
 524                 );
 525                 if ( !isset( $typemap[$params['mimeType']] ) ) {
 526                         $err = 'Image type not supported';
 527                         wfDebug( "$err\n" );
 528                         $errMsg = wfMsg ( 'thumbnail_image-type' );
 529                         return $this->getMediaTransformError( $params, $errMsg );
 530                 }
 531                 list( $loader, $colorStyle, $saveType ) = $typemap[$params['mimeType']];
 532
 533                 if ( !function_exists( $loader ) ) {
 534                         $err = "Incomplete GD library configuration: missing function $loader";
 535                         wfDebug( "$err\n" );
 536                         $errMsg = wfMsg ( 'thumbnail_gd-library', $loader );
 537                         return $this->getMediaTransformError( $params, $errMsg );
 538                 }
 539
 540                 if ( !file_exists( $params['srcPath'] ) ) {
 541                         $err = "File seems to be missing: {$params['srcPath']}";
 542                         wfDebug( "$err\n" );
 543                         $errMsg = wfMsg ( 'thumbnail_image-missing', $params['srcPath'] );
 544                         return $this->getMediaTransformError( $params, $errMsg );
 545                 }
 546
 547                 $src_image = call_user_func( $loader, $params['srcPath'] );
 548
 549                 $rotation = function_exists( 'imagerotate' ) ? $this->getRotation( $image ) : 0;
 550                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 551                 $dst_image = imagecreatetruecolor( $width, $height );
 552
 553                 // Initialise the destination image to transparent instead of
 554                 // the default solid black, to support PNG and GIF transparency nicely
 555                 $background = imagecolorallocate( $dst_image, 0, 0, 0 );
 556                 imagecolortransparent( $dst_image, $background );
 557                 imagealphablending( $dst_image, false );
 558
 559                 if ( $colorStyle == 'palette' ) {
 560                         // Don't resample for paletted GIF images.
 561                         // It may just uglify them, and completely breaks transparency.
 562                         imagecopyresized( $dst_image, $src_image,
 563                                 0, 0, 0, 0,
 564                                 $width, $height,
 565                                 imagesx( $src_image ), imagesy( $src_image ) );
 566                 } else {
 567                         imagecopyresampled( $dst_image, $src_image,
 568                                 0, 0, 0, 0,
 569                                 $width, $height,
 570                                 imagesx( $src_image ), imagesy( $src_image ) );
 571                 }
 572
 573                 if ( $rotation % 360 != 0 && $rotation % 90 == 0 ) {
 574                         $rot_image = imagerotate( $dst_image, $rotation, 0 );
 575                         imagedestroy( $dst_image );
 576                         $dst_image = $rot_image;
 577                 }
 578
 579                 imagesavealpha( $dst_image, true );
 580
 581                 call_user_func( $saveType, $dst_image, $params['dstPath'] );
 582                 imagedestroy( $dst_image );
 583                 imagedestroy( $src_image );
 584
 585                 return false; # No error
 586         }
 587
 588         /**
 589          * Escape a string for ImageMagick's property input (e.g. -set -comment)
 590          * See InterpretImageProperties() in magick/property.c
 591          */
 592         function escapeMagickProperty( $s ) {
 593                 // Double the backslashes
 594                 $s = str_replace( '\\', '\\\\', $s );
 595                 // Double the percents
 596                 $s = str_replace( '%', '%%', $s );
 597                 // Escape initial - or @
 598                 if ( strlen( $s ) > 0 && ( $s[0] === '-' || $s[0] === '@' ) ) {
 599                         $s = '\\' . $s;
 600                 }
 601                 return $s;
 602         }
 603
 604         /**
 605          * Escape a string for ImageMagick's input filenames. See ExpandFilenames()
 606          * and GetPathComponent() in magick/utility.c.
 607          *
 608          * This won't work with an initial ~ or @, so input files should be prefixed
 609          * with the directory name.
 610          *
 611          * Glob character unescaping is broken in ImageMagick before 6.6.1-5, but
 612          * it's broken in a way that doesn't involve trying to convert every file
 613          * in a directory, so we're better off escaping and waiting for the bugfix
 614          * to filter down to users.
 615          *
 616          * @param $path string The file path
 617          * @param $scene string The scene specification, or false if there is none
 618          */
 619         function escapeMagickInput( $path, $scene = false ) {
 620                 # Die on initial metacharacters (caller should prepend path)
 621                 $firstChar = substr( $path, 0, 1 );
 622                 if ( $firstChar === '~' || $firstChar === '@' ) {
 623                         throw new MWException( __METHOD__ . ': cannot escape this path name' );
 624                 }
 625
 626                 # Escape glob chars
 627                 $path = preg_replace( '/[*?\[\]{}]/', '\\\\\0', $path );
 628
 629                 return $this->escapeMagickPath( $path, $scene );
 630         }
 631
 632         /**
 633          * Escape a string for ImageMagick's output filename. See
 634          * InterpretImageFilename() in magick/image.c.
 635          */
 636         function escapeMagickOutput( $path, $scene = false ) {
 637                 $path = str_replace( '%', '%%', $path );
 638                 return $this->escapeMagickPath( $path, $scene );
 639         }
 640
 641         /**
 642          * Armour a string against ImageMagick's GetPathComponent(). This is a
 643          * helper function for escapeMagickInput() and escapeMagickOutput().
 644          *
 645          * @param $path string The file path
 646          * @param $scene string The scene specification, or false if there is none
 647          */
 648         protected function escapeMagickPath( $path, $scene = false ) {
 649                 # Die on format specifiers (other than drive letters). The regex is
 650                 # meant to match all the formats you get from "convert -list format"
 651                 if ( preg_match( '/^([a-zA-Z0-9-]+):/', $path, $m ) ) {
 652                         if ( wfIsWindows() && is_dir( $m[0] ) ) {
 653                                 // OK, it's a drive letter
 654                                 // ImageMagick has a similar exception, see IsMagickConflict()
 655                         } else {
 656                                 throw new MWException( __METHOD__ . ': unexpected colon character in path name' );
 657                         }
 658                 }
 659
 660                 # If there are square brackets, add a do-nothing scene specification
 661                 # to force a literal interpretation
 662                 if ( $scene === false ) {
 663                         if ( strpos( $path, '[' ) !== false ) {
 664                                 $path .= '[0--1]';
 665                         }
 666                 } else {
 667                         $path .= "[$scene]";
 668                 }
 669                 return $path;
 670         }
 671
 672         /**
 673          * Retrieve the version of the installed ImageMagick
 674          * You can use PHPs version_compare() to use this value
 675          * Value is cached for one hour.
 676          * @return String representing the IM version.
 677          */
 678         protected function getMagickVersion() {
 679                 global $wgMemc;
 680
 681                 $cache = $wgMemc->get( "imagemagick-version" );
 682                 if ( !$cache ) {
 683                         global $wgImageMagickConvertCommand;
 684                         $cmd = wfEscapeShellArg( $wgImageMagickConvertCommand ) . ' -version';
 685                         wfDebug( __METHOD__ . ": Running convert -version\n" );
 686                         $retval = '';
 687                         $return = wfShellExec( $cmd, $retval );
 688                         $x = preg_match( '/Version: ImageMagick ([0-9]*\.[0-9]*\.[0-9]*)/', $return, $matches );
 689                         if ( $x != 1 ) {
 690                                 wfDebug( __METHOD__ . ": ImageMagick version check failed\n" );
 691                                 return null;
 692                         }
 693                         $wgMemc->set( "imagemagick-version", $matches[1], 3600 );
 694                         return $matches[1];
 695                 }
 696                 return $cache;
 697         }
 698
 699         static function imageJpegWrapper( $dst_image, $thumbPath ) {
 700                 imageinterlace( $dst_image );
 701                 imagejpeg( $dst_image, $thumbPath, 95 );
 702         }
 703
 704         /**
 705          * On supporting image formats, try to read out the low-level orientation
 706          * of the file and return the angle that the file needs to be rotated to
 707          * be viewed.
 708          *
 709          * This information is only useful when manipulating the original file;
 710          * the width and height we normally work with is logical, and will match
 711          * any produced output views.
 712          *
 713          * The base BitmapHandler doesn't understand any metadata formats, so this
 714          * is left up to child classes to implement.
 715          *
 716          * @param $file File
 717          * @return int 0, 90, 180 or 270
 718          */
 719         public function getRotation( $file ) {
 720                 return 0;
 721         }
 722
 723         /**
 724          * Returns whether the current scaler supports rotation (im and gd do)
 725          *
 726          * @return bool
 727          */
 728         public static function canRotate() {
 729                 $scaler = self::getScalerType( null, false );
 730                 switch ( $scaler ) {
 731                         case 'im':
 732                                 # ImageMagick supports autorotation
 733                                 return true;
 734                         case 'imext':
 735                                 # Imagick::rotateImage
 736                                 return true;
 737                         case 'gd':
 738                                 # GD's imagerotate function is used to rotate images, but not
 739                                 # all precompiled PHP versions have that function
 740                                 return function_exists( 'imagerotate' );
 741                         default:
 742                                 # Other scalers don't support rotation
 743                                 return false;
 744                 }
 745         }
 746
 747         /**
 748          * Rerurns whether the file needs to be rendered. Returns true if the
 749          * file requires rotation and we are able to rotate it.
 750          *
 751          * @param $file File
 752          * @return bool
 753          */
 754         public function mustRender( $file ) {
 755                 return self::canRotate() && $this->getRotation( $file ) != 0;
 756         }
 757 }