includes/media/Bitmap.php

   1 <?php
   2 /**
   3  * Generic handler for bitmap images.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Media
  22  */
  23
  24 /**
  25  * Generic handler for bitmap images
  26  *
  27  * @ingroup Media
  28  */
  29 class BitmapHandler extends ImageHandler {
  30         /**
  31          * @param File $image
  32          * @param array $params Transform parameters. Entries with the keys 'width'
  33          * and 'height' are the respective screen width and height, while the keys
  34          * 'physicalWidth' and 'physicalHeight' indicate the thumbnail dimensions.
  35          * @return bool
  36          */
  37         function normaliseParams( $image, &$params ) {
  38                 if ( !parent::normaliseParams( $image, $params ) ) {
  39                         return false;
  40                 }
  41
  42                 # Obtain the source, pre-rotation dimensions
  43                 $srcWidth = $image->getWidth( $params['page'] );
  44                 $srcHeight = $image->getHeight( $params['page'] );
  45
  46                 # Don't make an image bigger than the source
  47                 if ( $params['physicalWidth'] >= $srcWidth ) {
  48                         $params['physicalWidth'] = $srcWidth;
  49                         $params['physicalHeight'] = $srcHeight;
  50
  51                         # Skip scaling limit checks if no scaling is required
  52                         # due to requested size being bigger than source.
  53                         if ( !$image->mustRender() ) {
  54                                 return true;
  55                         }
  56                 }
  57
  58                 # Check if the file is smaller than the maximum image area for thumbnailing
  59                 $checkImageAreaHookResult = null;
  60                 wfRunHooks(
  61                         'BitmapHandlerCheckImageArea',
  62                         array( $image, &$params, &$checkImageAreaHookResult )
  63                 );
  64
  65                 if ( is_null( $checkImageAreaHookResult ) ) {
  66                         global $wgMaxImageArea;
  67
  68                         if ( $srcWidth * $srcHeight > $wgMaxImageArea
  69                                 && !( $image->getMimeType() == 'image/jpeg'
  70                                         && self::getScalerType( false, false ) == 'im' )
  71                         ) {
  72                                 # Only ImageMagick can efficiently downsize jpg images without loading
  73                                 # the entire file in memory
  74                                 return false;
  75                         }
  76                 } else {
  77                         return $checkImageAreaHookResult;
  78                 }
  79
  80                 return true;
  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 array $params Parameters as returned by normaliseParams
  92          * @param int $rotation The rotation angle that will be applied
  93          * @return array ($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
 105                 return array( $width, $height );
 106         }
 107
 108         /**
 109          * @param File $image
 110          * @param string $dstPath
 111          * @param string $dstUrl
 112          * @param array $params
 113          * @param int $flags
 114          * @return MediaTransformError|ThumbnailImage|TransformParameterError
 115          */
 116         function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
 117                 if ( !$this->normaliseParams( $image, $params ) ) {
 118                         return new TransformParameterError( $params );
 119                 }
 120                 # Create a parameter array to pass to the scaler
 121                 $scalerParams = array(
 122                         # The size to which the image will be resized
 123                         'physicalWidth' => $params['physicalWidth'],
 124                         'physicalHeight' => $params['physicalHeight'],
 125                         'physicalDimensions' => "{$params['physicalWidth']}x{$params['physicalHeight']}",
 126                         # The size of the image on the page
 127                         'clientWidth' => $params['width'],
 128                         'clientHeight' => $params['height'],
 129                         # Comment as will be added to the Exif of the thumbnail
 130                         'comment' => isset( $params['descriptionUrl'] )
 131                                 ? "File source: {$params['descriptionUrl']}"
 132                                 : '',
 133                         # Properties of the original image
 134                         'srcWidth' => $image->getWidth(),
 135                         'srcHeight' => $image->getHeight(),
 136                         'mimeType' => $image->getMimeType(),
 137                         'dstPath' => $dstPath,
 138                         'dstUrl' => $dstUrl,
 139                 );
 140
 141                 # Determine scaler type
 142                 $scaler = self::getScalerType( $dstPath );
 143
 144                 wfDebug( __METHOD__ . ": creating {$scalerParams['physicalDimensions']} " .
 145                         "thumbnail at $dstPath using scaler $scaler\n" );
 146
 147                 if ( !$image->mustRender() &&
 148                         $scalerParams['physicalWidth'] == $scalerParams['srcWidth']
 149                         && $scalerParams['physicalHeight'] == $scalerParams['srcHeight']
 150                 ) {
 151
 152                         # normaliseParams (or the user) wants us to return the unscaled image
 153                         wfDebug( __METHOD__ . ": returning unscaled image\n" );
 154
 155                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 156                 }
 157
 158                 if ( $scaler == 'client' ) {
 159                         # Client-side image scaling, use the source URL
 160                         # Using the destination URL in a TRANSFORM_LATER request would be incorrect
 161                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 162                 }
 163
 164                 if ( $flags & self::TRANSFORM_LATER ) {
 165                         wfDebug( __METHOD__ . ": Transforming later per flags.\n" );
 166                         $params = array(
 167                                 'width' => $scalerParams['clientWidth'],
 168                                 'height' => $scalerParams['clientHeight']
 169                         );
 170
 171                         return new ThumbnailImage( $image, $dstUrl, false, $params );
 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 " .
 177                                 "directory, falling back to client scaling\n" );
 178
 179                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 180                 }
 181
 182                 # Transform functions and binaries need a FS source file
 183                 $scalerParams['srcPath'] = $image->getLocalRefPath();
 184                 if ( $scalerParams['srcPath'] === false ) { // Failed to get local copy
 185                         wfDebugLog( 'thumbnail',
 186                                 sprintf( 'Thumbnail failed on %s: could not get local copy of "%s"',
 187                                         wfHostname(), $image->getName() ) );
 188
 189                         return new MediaTransformError( 'thumbnail_error',
 190                                 $scalerParams['clientWidth'], $scalerParams['clientHeight'],
 191                                 wfMessage( 'filemissing' )->text()
 192                         );
 193                 }
 194
 195                 # Try a hook
 196                 $mto = null;
 197                 wfRunHooks( 'BitmapHandlerTransform', array( $this, $image, &$scalerParams, &$mto ) );
 198                 if ( !is_null( $mto ) ) {
 199                         wfDebug( __METHOD__ . ": Hook to BitmapHandlerTransform created an mto\n" );
 200                         $scaler = 'hookaborted';
 201                 }
 202
 203                 switch ( $scaler ) {
 204                         case 'hookaborted':
 205                                 # Handled by the hook above
 206                                 /** @var MediaTransformOutput $mto */
 207                                 $err = $mto->isError() ? $mto : false;
 208                                 break;
 209                         case 'im':
 210                                 $err = $this->transformImageMagick( $image, $scalerParams );
 211                                 break;
 212                         case 'custom':
 213                                 $err = $this->transformCustom( $image, $scalerParams );
 214                                 break;
 215                         case 'imext':
 216                                 $err = $this->transformImageMagickExt( $image, $scalerParams );
 217                                 break;
 218                         case 'gd':
 219                         default:
 220                                 $err = $this->transformGd( $image, $scalerParams );
 221                                 break;
 222                 }
 223
 224                 # Remove the file if a zero-byte thumbnail was created, or if there was an error
 225                 $removed = $this->removeBadFile( $dstPath, (bool)$err );
 226                 if ( $err ) {
 227                         # transform returned MediaTransforError
 228                         return $err;
 229                 } elseif ( $removed ) {
 230                         # Thumbnail was zero-byte and had to be removed
 231                         return new MediaTransformError( 'thumbnail_error',
 232                                 $scalerParams['clientWidth'], $scalerParams['clientHeight'],
 233                                 wfMessage( 'unknown-error' )->text()
 234                         );
 235                 } elseif ( $mto ) {
 236                         return $mto;
 237                 } else {
 238                         $params = array(
 239                                 'width' => $scalerParams['clientWidth'],
 240                                 'height' => $scalerParams['clientHeight']
 241                         );
 242
 243                         return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
 244                 }
 245         }
 246
 247         /**
 248          * Returns which scaler type should be used. Creates parent directories
 249          * for $dstPath and returns 'client' on error
 250          *
 251          * @param string $dstPath
 252          * @param bool $checkDstPath
 253          * @return string One of client, im, custom, gd, imext
 254          */
 255         protected static function getScalerType( $dstPath, $checkDstPath = true ) {
 256                 global $wgUseImageResize, $wgUseImageMagick, $wgCustomConvertCommand;
 257
 258                 if ( !$dstPath && $checkDstPath ) {
 259                         # No output path available, client side scaling only
 260                         $scaler = 'client';
 261                 } elseif ( !$wgUseImageResize ) {
 262                         $scaler = 'client';
 263                 } elseif ( $wgUseImageMagick ) {
 264                         $scaler = 'im';
 265                 } elseif ( $wgCustomConvertCommand ) {
 266                         $scaler = 'custom';
 267                 } elseif ( function_exists( 'imagecreatetruecolor' ) ) {
 268                         $scaler = 'gd';
 269                 } elseif ( class_exists( 'Imagick' ) ) {
 270                         $scaler = 'imext';
 271                 } else {
 272                         $scaler = 'client';
 273                 }
 274
 275                 return $scaler;
 276         }
 277
 278         /**
 279          * Get a ThumbnailImage that respresents an image that will be scaled
 280          * client side
 281          *
 282          * @param File $image File associated with this thumbnail
 283          * @param array $scalerParams Array with scaler params
 284          * @return ThumbnailImage
 285          *
 286          * @todo FIXME: No rotation support
 287          */
 288         protected function getClientScalingThumbnailImage( $image, $scalerParams ) {
 289                 $params = array(
 290                         'width' => $scalerParams['clientWidth'],
 291                         'height' => $scalerParams['clientHeight']
 292                 );
 293
 294                 return new ThumbnailImage( $image, $image->getURL(), null, $params );
 295         }
 296
 297         /**
 298          * Transform an image using ImageMagick
 299          *
 300          * @param File $image File associated with this thumbnail
 301          * @param array $params Array with scaler params
 302          *
 303          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 304          */
 305         protected function transformImageMagick( $image, $params ) {
 306                 # use ImageMagick
 307                 global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea,
 308                         $wgImageMagickTempDir, $wgImageMagickConvertCommand;
 309
 310                 $quality = '';
 311                 $sharpen = '';
 312                 $scene = false;
 313                 $animation_pre = '';
 314                 $animation_post = '';
 315                 $decoderHint = '';
 316                 if ( $params['mimeType'] == 'image/jpeg' ) {
 317                         $quality = "-quality 80"; // 80%
 318                         # Sharpening, see bug 6193
 319                         if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 320                                 / ( $params['srcWidth'] + $params['srcHeight'] )
 321                                 < $wgSharpenReductionThreshold
 322                         ) {
 323                                 $sharpen = "-sharpen " . wfEscapeShellArg( $wgSharpenParameter );
 324                         }
 325                         if ( version_compare( $this->getMagickVersion(), "6.5.6" ) >= 0 ) {
 326                                 // JPEG decoder hint to reduce memory, available since IM 6.5.6-2
 327                                 $decoderHint = "-define jpeg:size={$params['physicalDimensions']}";
 328                         }
 329                 } elseif ( $params['mimeType'] == 'image/png' ) {
 330                         $quality = "-quality 95"; // zlib 9, adaptive filtering
 331
 332                 } elseif ( $params['mimeType'] == 'image/gif' ) {
 333                         if ( $this->getImageArea( $image ) > $wgMaxAnimatedGifArea ) {
 334                                 // Extract initial frame only; we're so big it'll
 335                                 // be a total drag. :P
 336                                 $scene = 0;
 337                         } elseif ( $this->isAnimatedImage( $image ) ) {
 338                                 // Coalesce is needed to scale animated GIFs properly (bug 1017).
 339                                 $animation_pre = '-coalesce';
 340                                 // We optimize the output, but -optimize is broken,
 341                                 // use optimizeTransparency instead (bug 11822)
 342                                 if ( version_compare( $this->getMagickVersion(), "6.3.5" ) >= 0 ) {
 343                                         $animation_post = '-fuzz 5% -layers optimizeTransparency';
 344                                 }
 345                         }
 346                 } elseif ( $params['mimeType'] == 'image/x-xcf' ) {
 347                         $animation_post = '-layers merge';
 348                 }
 349
 350                 // Use one thread only, to avoid deadlock bugs on OOM
 351                 $env = array( 'OMP_NUM_THREADS' => 1 );
 352                 if ( strval( $wgImageMagickTempDir ) !== '' ) {
 353                         $env['MAGICK_TMPDIR'] = $wgImageMagickTempDir;
 354                 }
 355
 356                 $rotation = $this->getRotation( $image );
 357                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 358
 359                 $cmd =
 360                         wfEscapeShellArg( $wgImageMagickConvertCommand ) .
 361                         // Specify white background color, will be used for transparent images
 362                         // in Internet Explorer/Windows instead of default black.
 363                         " {$quality} -background white" .
 364                         " {$decoderHint} " .
 365                         wfEscapeShellArg( $this->escapeMagickInput( $params['srcPath'], $scene ) ) .
 366                         " {$animation_pre}" .
 367                         // For the -thumbnail option a "!" is needed to force exact size,
 368                         // or ImageMagick may decide your ratio is wrong and slice off
 369                         // a pixel.
 370                         " -thumbnail " . wfEscapeShellArg( "{$width}x{$height}!" ) .
 371                         // Add the source url as a comment to the thumb, but don't add the flag if there's no comment
 372                         ( $params['comment'] !== ''
 373                                 ? " -set comment " . wfEscapeShellArg( $this->escapeMagickProperty( $params['comment'] ) )
 374                                 : '' ) .
 375                         " -depth 8 $sharpen " .
 376                         " -rotate -$rotation " .
 377                         " {$animation_post} " .
 378                         wfEscapeShellArg( $this->escapeMagickOutput( $params['dstPath'] ) );
 379
 380                 wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
 381                 wfProfileIn( 'convert' );
 382                 $retval = 0;
 383                 $err = wfShellExecWithStderr( $cmd, $retval, $env );
 384                 wfProfileOut( 'convert' );
 385
 386                 if ( $retval !== 0 ) {
 387                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 388
 389                         return $this->getMediaTransformError( $params, "$err\nError code: $retval" );
 390                 }
 391
 392                 return false; # No error
 393         }
 394
 395         /**
 396          * Transform an image using the Imagick PHP extension
 397          *
 398          * @param File $image File associated with this thumbnail
 399          * @param array $params Array with scaler params
 400          *
 401          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 402          */
 403         protected function transformImageMagickExt( $image, $params ) {
 404                 global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea;
 405
 406                 try {
 407                         $im = new Imagick();
 408                         $im->readImage( $params['srcPath'] );
 409
 410                         if ( $params['mimeType'] == 'image/jpeg' ) {
 411                                 // Sharpening, see bug 6193
 412                                 if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 413                                         / ( $params['srcWidth'] + $params['srcHeight'] )
 414                                         < $wgSharpenReductionThreshold
 415                                 ) {
 416                                         // Hack, since $wgSharpenParamater is written specifically for the command line convert
 417                                         list( $radius, $sigma ) = explode( 'x', $wgSharpenParameter );
 418                                         $im->sharpenImage( $radius, $sigma );
 419                                 }
 420                                 $im->setCompressionQuality( 80 );
 421                         } elseif ( $params['mimeType'] == 'image/png' ) {
 422                                 $im->setCompressionQuality( 95 );
 423                         } elseif ( $params['mimeType'] == 'image/gif' ) {
 424                                 if ( $this->getImageArea( $image ) > $wgMaxAnimatedGifArea ) {
 425                                         // Extract initial frame only; we're so big it'll
 426                                         // be a total drag. :P
 427                                         $im->setImageScene( 0 );
 428                                 } elseif ( $this->isAnimatedImage( $image ) ) {
 429                                         // Coalesce is needed to scale animated GIFs properly (bug 1017).
 430                                         $im = $im->coalesceImages();
 431                                 }
 432                         }
 433
 434                         $rotation = $this->getRotation( $image );
 435                         list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 436
 437                         $im->setImageBackgroundColor( new ImagickPixel( 'white' ) );
 438
 439                         // Call Imagick::thumbnailImage on each frame
 440                         foreach ( $im as $i => $frame ) {
 441                                 if ( !$frame->thumbnailImage( $width, $height, /* fit */ false ) ) {
 442                                         return $this->getMediaTransformError( $params, "Error scaling frame $i" );
 443                                 }
 444                         }
 445                         $im->setImageDepth( 8 );
 446
 447                         if ( $rotation ) {
 448                                 if ( !$im->rotateImage( new ImagickPixel( 'white' ), 360 - $rotation ) ) {
 449                                         return $this->getMediaTransformError( $params, "Error rotating $rotation degrees" );
 450                                 }
 451                         }
 452
 453                         if ( $this->isAnimatedImage( $image ) ) {
 454                                 wfDebug( __METHOD__ . ": Writing animated thumbnail\n" );
 455                                 // This is broken somehow... can't find out how to fix it
 456                                 $result = $im->writeImages( $params['dstPath'], true );
 457                         } else {
 458                                 $result = $im->writeImage( $params['dstPath'] );
 459                         }
 460                         if ( !$result ) {
 461                                 return $this->getMediaTransformError( $params,
 462                                         "Unable to write thumbnail to {$params['dstPath']}" );
 463                         }
 464                 } catch ( ImagickException $e ) {
 465                         return $this->getMediaTransformError( $params, $e->getMessage() );
 466                 }
 467
 468                 return false;
 469         }
 470
 471         /**
 472          * Transform an image using a custom command
 473          *
 474          * @param File $image File associated with this thumbnail
 475          * @param array $params Array with scaler params
 476          *
 477          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 478          */
 479         protected function transformCustom( $image, $params ) {
 480                 # Use a custom convert command
 481                 global $wgCustomConvertCommand;
 482
 483                 # Variables: %s %d %w %h
 484                 $src = wfEscapeShellArg( $params['srcPath'] );
 485                 $dst = wfEscapeShellArg( $params['dstPath'] );
 486                 $cmd = $wgCustomConvertCommand;
 487                 $cmd = str_replace( '%s', $src, str_replace( '%d', $dst, $cmd ) ); # Filenames
 488                 $cmd = str_replace( '%h', $params['physicalHeight'],
 489                         str_replace( '%w', $params['physicalWidth'], $cmd ) ); # Size
 490                 wfDebug( __METHOD__ . ": Running custom convert command $cmd\n" );
 491                 wfProfileIn( 'convert' );
 492                 $retval = 0;
 493                 $err = wfShellExecWithStderr( $cmd, $retval );
 494                 wfProfileOut( 'convert' );
 495
 496                 if ( $retval !== 0 ) {
 497                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 498
 499                         return $this->getMediaTransformError( $params, $err );
 500                 }
 501
 502                 return false; # No error
 503         }
 504
 505         /**
 506          * Get a MediaTransformError with error 'thumbnail_error'
 507          *
 508          * @param array $params Parameter array as passed to the transform* functions
 509          * @param string $errMsg Error message
 510          * @return MediaTransformError
 511          */
 512         public function getMediaTransformError( $params, $errMsg ) {
 513                 return new MediaTransformError( 'thumbnail_error', $params['clientWidth'],
 514                         $params['clientHeight'], $errMsg );
 515         }
 516
 517         /**
 518          * Transform an image using the built in GD library
 519          *
 520          * @param File $image File associated with this thumbnail
 521          * @param array $params Array with scaler params
 522          *
 523          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 524          */
 525         protected function transformGd( $image, $params ) {
 526                 # Use PHP's builtin GD library functions.
 527                 #
 528                 # First find out what kind of file this is, and select the correct
 529                 # input routine for this.
 530
 531                 $typemap = array(
 532                         'image/gif' => array( 'imagecreatefromgif', 'palette', 'imagegif' ),
 533                         'image/jpeg' => array( 'imagecreatefromjpeg', 'truecolor',
 534                                 array( __CLASS__, 'imageJpegWrapper' ) ),
 535                         'image/png' => array( 'imagecreatefrompng', 'bits', 'imagepng' ),
 536                         'image/vnd.wap.wbmp' => array( 'imagecreatefromwbmp', 'palette', 'imagewbmp' ),
 537                         'image/xbm' => array( 'imagecreatefromxbm', 'palette', 'imagexbm' ),
 538                 );
 539                 if ( !isset( $typemap[$params['mimeType']] ) ) {
 540                         $err = 'Image type not supported';
 541                         wfDebug( "$err\n" );
 542                         $errMsg = wfMessage( 'thumbnail_image-type' )->text();
 543
 544                         return $this->getMediaTransformError( $params, $errMsg );
 545                 }
 546                 list( $loader, $colorStyle, $saveType ) = $typemap[$params['mimeType']];
 547
 548                 if ( !function_exists( $loader ) ) {
 549                         $err = "Incomplete GD library configuration: missing function $loader";
 550                         wfDebug( "$err\n" );
 551                         $errMsg = wfMessage( 'thumbnail_gd-library', $loader )->text();
 552
 553                         return $this->getMediaTransformError( $params, $errMsg );
 554                 }
 555
 556                 if ( !file_exists( $params['srcPath'] ) ) {
 557                         $err = "File seems to be missing: {$params['srcPath']}";
 558                         wfDebug( "$err\n" );
 559                         $errMsg = wfMessage( 'thumbnail_image-missing', $params['srcPath'] )->text();
 560
 561                         return $this->getMediaTransformError( $params, $errMsg );
 562                 }
 563
 564                 $src_image = call_user_func( $loader, $params['srcPath'] );
 565
 566                 $rotation = function_exists( 'imagerotate' ) ? $this->getRotation( $image ) : 0;
 567                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 568                 $dst_image = imagecreatetruecolor( $width, $height );
 569
 570                 // Initialise the destination image to transparent instead of
 571                 // the default solid black, to support PNG and GIF transparency nicely
 572                 $background = imagecolorallocate( $dst_image, 0, 0, 0 );
 573                 imagecolortransparent( $dst_image, $background );
 574                 imagealphablending( $dst_image, false );
 575
 576                 if ( $colorStyle == 'palette' ) {
 577                         // Don't resample for paletted GIF images.
 578                         // It may just uglify them, and completely breaks transparency.
 579                         imagecopyresized( $dst_image, $src_image,
 580                                 0, 0, 0, 0,
 581                                 $width, $height,
 582                                 imagesx( $src_image ), imagesy( $src_image ) );
 583                 } else {
 584                         imagecopyresampled( $dst_image, $src_image,
 585                                 0, 0, 0, 0,
 586                                 $width, $height,
 587                                 imagesx( $src_image ), imagesy( $src_image ) );
 588                 }
 589
 590                 if ( $rotation % 360 != 0 && $rotation % 90 == 0 ) {
 591                         $rot_image = imagerotate( $dst_image, $rotation, 0 );
 592                         imagedestroy( $dst_image );
 593                         $dst_image = $rot_image;
 594                 }
 595
 596                 imagesavealpha( $dst_image, true );
 597
 598                 call_user_func( $saveType, $dst_image, $params['dstPath'] );
 599                 imagedestroy( $dst_image );
 600                 imagedestroy( $src_image );
 601
 602                 return false; # No error
 603         }
 604
 605         /**
 606          * Escape a string for ImageMagick's property input (e.g. -set -comment)
 607          * See InterpretImageProperties() in magick/property.c
 608          * @param string $s
 609          * @return string
 610          */
 611         function escapeMagickProperty( $s ) {
 612                 // Double the backslashes
 613                 $s = str_replace( '\\', '\\\\', $s );
 614                 // Double the percents
 615                 $s = str_replace( '%', '%%', $s );
 616                 // Escape initial - or @
 617                 if ( strlen( $s ) > 0 && ( $s[0] === '-' || $s[0] === '@' ) ) {
 618                         $s = '\\' . $s;
 619                 }
 620
 621                 return $s;
 622         }
 623
 624         /**
 625          * Escape a string for ImageMagick's input filenames. See ExpandFilenames()
 626          * and GetPathComponent() in magick/utility.c.
 627          *
 628          * This won't work with an initial ~ or @, so input files should be prefixed
 629          * with the directory name.
 630          *
 631          * Glob character unescaping is broken in ImageMagick before 6.6.1-5, but
 632          * it's broken in a way that doesn't involve trying to convert every file
 633          * in a directory, so we're better off escaping and waiting for the bugfix
 634          * to filter down to users.
 635          *
 636          * @param string $path The file path
 637          * @param bool|string $scene The scene specification, or false if there is none
 638          * @throws MWException
 639          * @return string
 640          */
 641         function escapeMagickInput( $path, $scene = false ) {
 642                 # Die on initial metacharacters (caller should prepend path)
 643                 $firstChar = substr( $path, 0, 1 );
 644                 if ( $firstChar === '~' || $firstChar === '@' ) {
 645                         throw new MWException( __METHOD__ . ': cannot escape this path name' );
 646                 }
 647
 648                 # Escape glob chars
 649                 $path = preg_replace( '/[*?\[\]{}]/', '\\\\\0', $path );
 650
 651                 return $this->escapeMagickPath( $path, $scene );
 652         }
 653
 654         /**
 655          * Escape a string for ImageMagick's output filename. See
 656          * InterpretImageFilename() in magick/image.c.
 657          * @param string $path The file path
 658          * @param bool|string $scene The scene specification, or false if there is none
 659          * @return string
 660          */
 661         function escapeMagickOutput( $path, $scene = false ) {
 662                 $path = str_replace( '%', '%%', $path );
 663
 664                 return $this->escapeMagickPath( $path, $scene );
 665         }
 666
 667         /**
 668          * Armour a string against ImageMagick's GetPathComponent(). This is a
 669          * helper function for escapeMagickInput() and escapeMagickOutput().
 670          *
 671          * @param string $path The file path
 672          * @param bool|string $scene The scene specification, or false if there is none
 673          * @throws MWException
 674          * @return string
 675          */
 676         protected function escapeMagickPath( $path, $scene = false ) {
 677                 # Die on format specifiers (other than drive letters). The regex is
 678                 # meant to match all the formats you get from "convert -list format"
 679                 if ( preg_match( '/^([a-zA-Z0-9-]+):/', $path, $m ) ) {
 680                         if ( wfIsWindows() && is_dir( $m[0] ) ) {
 681                                 // OK, it's a drive letter
 682                                 // ImageMagick has a similar exception, see IsMagickConflict()
 683                         } else {
 684                                 throw new MWException( __METHOD__ . ': unexpected colon character in path name' );
 685                         }
 686                 }
 687
 688                 # If there are square brackets, add a do-nothing scene specification
 689                 # to force a literal interpretation
 690                 if ( $scene === false ) {
 691                         if ( strpos( $path, '[' ) !== false ) {
 692                                 $path .= '[0--1]';
 693                         }
 694                 } else {
 695                         $path .= "[$scene]";
 696                 }
 697
 698                 return $path;
 699         }
 700
 701         /**
 702          * Retrieve the version of the installed ImageMagick
 703          * You can use PHPs version_compare() to use this value
 704          * Value is cached for one hour.
 705          * @return string Representing the IM version.
 706          */
 707         protected function getMagickVersion() {
 708                 global $wgMemc;
 709
 710                 $cache = $wgMemc->get( "imagemagick-version" );
 711                 if ( !$cache ) {
 712                         global $wgImageMagickConvertCommand;
 713                         $cmd = wfEscapeShellArg( $wgImageMagickConvertCommand ) . ' -version';
 714                         wfDebug( __METHOD__ . ": Running convert -version\n" );
 715                         $retval = '';
 716                         $return = wfShellExec( $cmd, $retval );
 717                         $x = preg_match( '/Version: ImageMagick ([0-9]*\.[0-9]*\.[0-9]*)/', $return, $matches );
 718                         if ( $x != 1 ) {
 719                                 wfDebug( __METHOD__ . ": ImageMagick version check failed\n" );
 720
 721                                 return null;
 722                         }
 723                         $wgMemc->set( "imagemagick-version", $matches[1], 3600 );
 724
 725                         return $matches[1];
 726                 }
 727
 728                 return $cache;
 729         }
 730
 731         static function imageJpegWrapper( $dst_image, $thumbPath ) {
 732                 imageinterlace( $dst_image );
 733                 imagejpeg( $dst_image, $thumbPath, 95 );
 734         }
 735
 736         /**
 737          * Returns whether the current scaler supports rotation (im and gd do)
 738          *
 739          * @return bool
 740          */
 741         public static function canRotate() {
 742                 $scaler = self::getScalerType( null, false );
 743                 switch ( $scaler ) {
 744                         case 'im':
 745                                 # ImageMagick supports autorotation
 746                                 return true;
 747                         case 'imext':
 748                                 # Imagick::rotateImage
 749                                 return true;
 750                         case 'gd':
 751                                 # GD's imagerotate function is used to rotate images, but not
 752                                 # all precompiled PHP versions have that function
 753                                 return function_exists( 'imagerotate' );
 754                         default:
 755                                 # Other scalers don't support rotation
 756                                 return false;
 757                 }
 758         }
 759
 760         /**
 761          * @see $wgEnableAutoRotation
 762          * @return bool Whether auto rotation is enabled
 763          */
 764         public static function autoRotateEnabled() {
 765                 global $wgEnableAutoRotation;
 766
 767                 if ( $wgEnableAutoRotation === null ) {
 768                         // Only enable auto-rotation when the bitmap handler can rotate
 769                         $wgEnableAutoRotation = BitmapHandler::canRotate();
 770                 }
 771
 772                 return $wgEnableAutoRotation;
 773         }
 774
 775         /**
 776          * @param File $file
 777          * @param array $params Rotate parameters.
 778          *   'rotation' clockwise rotation in degrees, allowed are multiples of 90
 779          * @since 1.21
 780          * @return bool
 781          */
 782         public function rotate( $file, $params ) {
 783                 global $wgImageMagickConvertCommand;
 784
 785                 $rotation = ( $params['rotation'] + $this->getRotation( $file ) ) % 360;
 786                 $scene = false;
 787
 788                 $scaler = self::getScalerType( null, false );
 789                 switch ( $scaler ) {
 790                         case 'im':
 791                                 $cmd = wfEscapeShellArg( $wgImageMagickConvertCommand ) . " " .
 792                                         wfEscapeShellArg( $this->escapeMagickInput( $params['srcPath'], $scene ) ) .
 793                                         " -rotate -$rotation " .
 794                                         wfEscapeShellArg( $this->escapeMagickOutput( $params['dstPath'] ) );
 795                                 wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
 796                                 wfProfileIn( 'convert' );
 797                                 $retval = 0;
 798                                 // @todo FIXME: Undefined variable %env
 799                                 $err = wfShellExecWithStderr( $cmd, $retval, $env );
 800                                 wfProfileOut( 'convert' );
 801                                 if ( $retval !== 0 ) {
 802                                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 803
 804                                         return new MediaTransformError( 'thumbnail_error', 0, 0, $err );
 805                                 }
 806
 807                                 return false;
 808                         case 'imext':
 809                                 $im = new Imagick();
 810                                 $im->readImage( $params['srcPath'] );
 811                                 if ( !$im->rotateImage( new ImagickPixel( 'white' ), 360 - $rotation ) ) {
 812                                         return new MediaTransformError( 'thumbnail_error', 0, 0,
 813                                                 "Error rotating $rotation degrees" );
 814                                 }
 815                                 $result = $im->writeImage( $params['dstPath'] );
 816                                 if ( !$result ) {
 817                                         return new MediaTransformError( 'thumbnail_error', 0, 0,
 818                                                 "Unable to write image to {$params['dstPath']}" );
 819                                 }
 820
 821                                 return false;
 822                         default:
 823                                 return new MediaTransformError( 'thumbnail_error', 0, 0,
 824                                         "$scaler rotation not implemented" );
 825                 }
 826         }
 827
 828         /**
 829          * Rerurns whether the file needs to be rendered. Returns true if the
 830          * file requires rotation and we are able to rotate it.
 831          *
 832          * @param File $file
 833          * @return bool
 834          */
 835         public function mustRender( $file ) {
 836                 return self::canRotate() && $this->getRotation( $file ) != 0;
 837         }
 838 }