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 TransformationalImageHandler {
  30
  31         /**
  32          * Returns which scaler type should be used. Creates parent directories
  33          * for $dstPath and returns 'client' on error
  34          *
  35          * @param string $dstPath
  36          * @param bool $checkDstPath
  37          * @return string|Callable One of client, im, custom, gd, imext or an array( object, method )
  38          */
  39         protected function getScalerType( $dstPath, $checkDstPath = true ) {
  40                 global $wgUseImageResize, $wgUseImageMagick, $wgCustomConvertCommand;
  41
  42                 if ( !$dstPath && $checkDstPath ) {
  43                         # No output path available, client side scaling only
  44                         $scaler = 'client';
  45                 } elseif ( !$wgUseImageResize ) {
  46                         $scaler = 'client';
  47                 } elseif ( $wgUseImageMagick ) {
  48                         $scaler = 'im';
  49                 } elseif ( $wgCustomConvertCommand ) {
  50                         $scaler = 'custom';
  51                 } elseif ( function_exists( 'imagecreatetruecolor' ) ) {
  52                         $scaler = 'gd';
  53                 } elseif ( class_exists( 'Imagick' ) ) {
  54                         $scaler = 'imext';
  55                 } else {
  56                         $scaler = 'client';
  57                 }
  58
  59                 return $scaler;
  60         }
  61
  62         public function makeParamString( $params ) {
  63                 $res = parent::makeParamString( $params );
  64                 if ( isset( $params['interlace'] ) && $params['interlace'] ) {
  65                         return "interlaced-{$res}";
  66                 } else {
  67                         return $res;
  68                 }
  69         }
  70
  71         public function parseParamString( $str ) {
  72                 $remainder = preg_replace( '/^interlaced-/', '', $str );
  73                 $params = parent::parseParamString( $remainder );
  74                 if ( $params === false ) {
  75                         return false;
  76                 }
  77                 $params['interlace'] = $str !== $remainder;
  78                 return $params;
  79         }
  80
  81         public function validateParam( $name, $value ) {
  82                 if ( $name === 'interlace' ) {
  83                         return $value === false || $value === true;
  84                 } else {
  85                         return parent::validateParam( $name, $value );
  86                 }
  87         }
  88
  89         /**
  90          * @param File $image
  91          * @param array $params
  92          * @return bool
  93          */
  94         function normaliseParams( $image, &$params ) {
  95                 global $wgMaxInterlacingAreas;
  96                 if ( !parent::normaliseParams( $image, $params ) ) {
  97                         return false;
  98                 }
  99                 $mimeType = $image->getMimeType();
 100                 $interlace = isset( $params['interlace'] ) && $params['interlace']
 101                         && isset( $wgMaxInterlacingAreas[$mimeType] )
 102                         && $this->getImageArea( $image ) <= $wgMaxInterlacingAreas[$mimeType];
 103                 $params['interlace'] = $interlace;
 104                 return true;
 105         }
 106
 107         /**
 108          * Get ImageMagick subsampling factors for the target JPEG pixel format.
 109          *
 110          * @param string $pixelFormat one of 'yuv444', 'yuv422', 'yuv420'
 111          * @return array of string keys
 112          */
 113         protected function imageMagickSubsampling( $pixelFormat ) {
 114                 switch ( $pixelFormat ) {
 115                 case 'yuv444':
 116                         return [ '1x1', '1x1', '1x1' ];
 117                 case 'yuv422':
 118                         return [ '2x1', '1x1', '1x1' ];
 119                 case 'yuv420':
 120                         return [ '2x2', '1x1', '1x1' ];
 121                 default:
 122                         throw new MWException( 'Invalid pixel format for JPEG output' );
 123                 }
 124         }
 125
 126         /**
 127          * Transform an image using ImageMagick
 128          *
 129          * @param File $image File associated with this thumbnail
 130          * @param array $params Array with scaler params
 131          *
 132          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 133          */
 134         protected function transformImageMagick( $image, $params ) {
 135                 # use ImageMagick
 136                 global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea,
 137                         $wgImageMagickTempDir, $wgImageMagickConvertCommand, $wgJpegPixelFormat;
 138
 139                 $quality = [];
 140                 $sharpen = [];
 141                 $scene = false;
 142                 $animation_pre = [];
 143                 $animation_post = [];
 144                 $decoderHint = [];
 145                 $subsampling = [];
 146
 147                 if ( $params['mimeType'] == 'image/jpeg' ) {
 148                         $qualityVal = isset( $params['quality'] ) ? (string)$params['quality'] : null;
 149                         $quality = [ '-quality', $qualityVal ?: '80' ]; // 80%
 150                         if ( $params['interlace'] ) {
 151                                 $animation_post = [ '-interlace', 'JPEG' ];
 152                         }
 153                         # Sharpening, see bug 6193
 154                         if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 155                                 / ( $params['srcWidth'] + $params['srcHeight'] )
 156                                 < $wgSharpenReductionThreshold
 157                         ) {
 158                                 $sharpen = [ '-sharpen', $wgSharpenParameter ];
 159                         }
 160                         if ( version_compare( $this->getMagickVersion(), "6.5.6" ) >= 0 ) {
 161                                 // JPEG decoder hint to reduce memory, available since IM 6.5.6-2
 162                                 $decoderHint = [ '-define', "jpeg:size={$params['physicalDimensions']}" ];
 163                         }
 164                         if ( $wgJpegPixelFormat ) {
 165                                 $factors = $this->imageMagickSubsampling( $wgJpegPixelFormat );
 166                                 $subsampling = [ '-sampling-factor', implode( ',', $factors ) ];
 167                         }
 168                 } elseif ( $params['mimeType'] == 'image/png' ) {
 169                         $quality = [ '-quality', '95' ]; // zlib 9, adaptive filtering
 170                         if ( $params['interlace'] ) {
 171                                 $animation_post = [ '-interlace', 'PNG' ];
 172                         }
 173                 } elseif ( $params['mimeType'] == 'image/webp' ) {
 174                         $quality = [ '-quality', '95' ]; // zlib 9, adaptive filtering
 175                 } elseif ( $params['mimeType'] == 'image/gif' ) {
 176                         if ( $this->getImageArea( $image ) > $wgMaxAnimatedGifArea ) {
 177                                 // Extract initial frame only; we're so big it'll
 178                                 // be a total drag. :P
 179                                 $scene = 0;
 180                         } elseif ( $this->isAnimatedImage( $image ) ) {
 181                                 // Coalesce is needed to scale animated GIFs properly (bug 1017).
 182                                 $animation_pre = [ '-coalesce' ];
 183                                 // We optimize the output, but -optimize is broken,
 184                                 // use optimizeTransparency instead (bug 11822)
 185                                 if ( version_compare( $this->getMagickVersion(), "6.3.5" ) >= 0 ) {
 186                                         $animation_post = [ '-fuzz', '5%', '-layers', 'optimizeTransparency' ];
 187                                 }
 188                         }
 189                         if ( $params['interlace'] && version_compare( $this->getMagickVersion(), "6.3.4" ) >= 0
 190                                 && !$this->isAnimatedImage( $image ) ) { // interlacing animated GIFs is a bad idea
 191                                 $animation_post[] = '-interlace';
 192                                 $animation_post[] = 'GIF';
 193                         }
 194                 } elseif ( $params['mimeType'] == 'image/x-xcf' ) {
 195                         // Before merging layers, we need to set the background
 196                         // to be transparent to preserve alpha, as -layers merge
 197                         // merges all layers on to a canvas filled with the
 198                         // background colour. After merging we reset the background
 199                         // to be white for the default background colour setting
 200                         // in the PNG image (which is used in old IE)
 201                         $animation_pre = [
 202                                 '-background', 'transparent',
 203                                 '-layers', 'merge',
 204                                 '-background', 'white',
 205                         ];
 206                         MediaWiki\suppressWarnings();
 207                         $xcfMeta = unserialize( $image->getMetadata() );
 208                         MediaWiki\restoreWarnings();
 209                         if ( $xcfMeta
 210                                 && isset( $xcfMeta['colorType'] )
 211                                 && $xcfMeta['colorType'] === 'greyscale-alpha'
 212                                 && version_compare( $this->getMagickVersion(), "6.8.9-3" ) < 0
 213                         ) {
 214                                 // bug 66323 - Greyscale images not rendered properly.
 215                                 // So only take the "red" channel.
 216                                 $channelOnly = [ '-channel', 'R', '-separate' ];
 217                                 $animation_pre = array_merge( $animation_pre, $channelOnly );
 218                         }
 219                 }
 220
 221                 // Use one thread only, to avoid deadlock bugs on OOM
 222                 $env = [ 'OMP_NUM_THREADS' => 1 ];
 223                 if ( strval( $wgImageMagickTempDir ) !== '' ) {
 224                         $env['MAGICK_TMPDIR'] = $wgImageMagickTempDir;
 225                 }
 226
 227                 $rotation = isset( $params['disableRotation'] ) ? 0 : $this->getRotation( $image );
 228                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 229
 230                 $cmd = call_user_func_array( 'wfEscapeShellArg', array_merge(
 231                         [ $wgImageMagickConvertCommand ],
 232                         $quality,
 233                         // Specify white background color, will be used for transparent images
 234                         // in Internet Explorer/Windows instead of default black.
 235                         [ '-background', 'white' ],
 236                         $decoderHint,
 237                         [ $this->escapeMagickInput( $params['srcPath'], $scene ) ],
 238                         $animation_pre,
 239                         // For the -thumbnail option a "!" is needed to force exact size,
 240                         // or ImageMagick may decide your ratio is wrong and slice off
 241                         // a pixel.
 242                         [ '-thumbnail', "{$width}x{$height}!" ],
 243                         // Add the source url as a comment to the thumb, but don't add the flag if there's no comment
 244                         ( $params['comment'] !== ''
 245                                 ? [ '-set', 'comment', $this->escapeMagickProperty( $params['comment'] ) ]
 246                                 : [] ),
 247                         // T108616: Avoid exposure of local file path
 248                         [ '+set', 'Thumb::URI' ],
 249                         [ '-depth', 8 ],
 250                         $sharpen,
 251                         [ '-rotate', "-$rotation" ],
 252                         $subsampling,
 253                         $animation_post,
 254                         [ $this->escapeMagickOutput( $params['dstPath'] ) ] ) );
 255
 256                 wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
 257                 $retval = 0;
 258                 $err = wfShellExecWithStderr( $cmd, $retval, $env );
 259
 260                 if ( $retval !== 0 ) {
 261                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 262
 263                         return $this->getMediaTransformError( $params, "$err\nError code: $retval" );
 264                 }
 265
 266                 return false; # No error
 267         }
 268
 269         /**
 270          * Transform an image using the Imagick PHP extension
 271          *
 272          * @param File $image File associated with this thumbnail
 273          * @param array $params Array with scaler params
 274          *
 275          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 276          */
 277         protected function transformImageMagickExt( $image, $params ) {
 278                 global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea,
 279                         $wgJpegPixelFormat;
 280
 281                 try {
 282                         $im = new Imagick();
 283                         $im->readImage( $params['srcPath'] );
 284
 285                         if ( $params['mimeType'] == 'image/jpeg' ) {
 286                                 // Sharpening, see bug 6193
 287                                 if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 288                                         / ( $params['srcWidth'] + $params['srcHeight'] )
 289                                         < $wgSharpenReductionThreshold
 290                                 ) {
 291                                         // Hack, since $wgSharpenParameter is written specifically for the command line convert
 292                                         list( $radius, $sigma ) = explode( 'x', $wgSharpenParameter );
 293                                         $im->sharpenImage( $radius, $sigma );
 294                                 }
 295                                 $qualityVal = isset( $params['quality'] ) ? (string)$params['quality'] : null;
 296                                 $im->setCompressionQuality( $qualityVal ?: 80 );
 297                                 if ( $params['interlace'] ) {
 298                                         $im->setInterlaceScheme( Imagick::INTERLACE_JPEG );
 299                                 }
 300                                 if ( $wgJpegPixelFormat ) {
 301                                         $factors = $this->imageMagickSubsampling( $wgJpegPixelFormat );
 302                                         $im->setSamplingFactors( $factors );
 303                                 }
 304                         } elseif ( $params['mimeType'] == 'image/png' ) {
 305                                 $im->setCompressionQuality( 95 );
 306                                 if ( $params['interlace'] ) {
 307                                         $im->setInterlaceScheme( Imagick::INTERLACE_PNG );
 308                                 }
 309                         } elseif ( $params['mimeType'] == 'image/gif' ) {
 310                                 if ( $this->getImageArea( $image ) > $wgMaxAnimatedGifArea ) {
 311                                         // Extract initial frame only; we're so big it'll
 312                                         // be a total drag. :P
 313                                         $im->setImageScene( 0 );
 314                                 } elseif ( $this->isAnimatedImage( $image ) ) {
 315                                         // Coalesce is needed to scale animated GIFs properly (bug 1017).
 316                                         $im = $im->coalesceImages();
 317                                 }
 318                                 // GIF interlacing is only available since 6.3.4
 319                                 $v = Imagick::getVersion();
 320                                 preg_match( '/ImageMagick ([0-9]+\.[0-9]+\.[0-9]+)/', $v['versionString'], $v );
 321
 322                                 if ( $params['interlace'] && version_compare( $v[1], '6.3.4' ) >= 0 ) {
 323                                         $im->setInterlaceScheme( Imagick::INTERLACE_GIF );
 324                                 }
 325                         }
 326
 327                         $rotation = isset( $params['disableRotation'] ) ? 0 : $this->getRotation( $image );
 328                         list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 329
 330                         $im->setImageBackgroundColor( new ImagickPixel( 'white' ) );
 331
 332                         // Call Imagick::thumbnailImage on each frame
 333                         foreach ( $im as $i => $frame ) {
 334                                 if ( !$frame->thumbnailImage( $width, $height, /* fit */ false ) ) {
 335                                         return $this->getMediaTransformError( $params, "Error scaling frame $i" );
 336                                 }
 337                         }
 338                         $im->setImageDepth( 8 );
 339
 340                         if ( $rotation ) {
 341                                 if ( !$im->rotateImage( new ImagickPixel( 'white' ), 360 - $rotation ) ) {
 342                                         return $this->getMediaTransformError( $params, "Error rotating $rotation degrees" );
 343                                 }
 344                         }
 345
 346                         if ( $this->isAnimatedImage( $image ) ) {
 347                                 wfDebug( __METHOD__ . ": Writing animated thumbnail\n" );
 348                                 // This is broken somehow... can't find out how to fix it
 349                                 $result = $im->writeImages( $params['dstPath'], true );
 350                         } else {
 351                                 $result = $im->writeImage( $params['dstPath'] );
 352                         }
 353                         if ( !$result ) {
 354                                 return $this->getMediaTransformError( $params,
 355                                         "Unable to write thumbnail to {$params['dstPath']}" );
 356                         }
 357                 } catch ( ImagickException $e ) {
 358                         return $this->getMediaTransformError( $params, $e->getMessage() );
 359                 }
 360
 361                 return false;
 362         }
 363
 364         /**
 365          * Transform an image using a custom command
 366          *
 367          * @param File $image File associated with this thumbnail
 368          * @param array $params Array with scaler params
 369          *
 370          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 371          */
 372         protected function transformCustom( $image, $params ) {
 373                 # Use a custom convert command
 374                 global $wgCustomConvertCommand;
 375
 376                 # Variables: %s %d %w %h
 377                 $src = wfEscapeShellArg( $params['srcPath'] );
 378                 $dst = wfEscapeShellArg( $params['dstPath'] );
 379                 $cmd = $wgCustomConvertCommand;
 380                 $cmd = str_replace( '%s', $src, str_replace( '%d', $dst, $cmd ) ); # Filenames
 381                 $cmd = str_replace( '%h', wfEscapeShellArg( $params['physicalHeight'] ),
 382                         str_replace( '%w', wfEscapeShellArg( $params['physicalWidth'] ), $cmd ) ); # Size
 383                 wfDebug( __METHOD__ . ": Running custom convert command $cmd\n" );
 384                 $retval = 0;
 385                 $err = wfShellExecWithStderr( $cmd, $retval );
 386
 387                 if ( $retval !== 0 ) {
 388                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 389
 390                         return $this->getMediaTransformError( $params, $err );
 391                 }
 392
 393                 return false; # No error
 394         }
 395
 396         /**
 397          * Transform an image using the built in GD library
 398          *
 399          * @param File $image File associated with this thumbnail
 400          * @param array $params Array with scaler params
 401          *
 402          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 403          */
 404         protected function transformGd( $image, $params ) {
 405                 # Use PHP's builtin GD library functions.
 406                 # First find out what kind of file this is, and select the correct
 407                 # input routine for this.
 408
 409                 $typemap = [
 410                         'image/gif' => [ 'imagecreatefromgif', 'palette', false, 'imagegif' ],
 411                         'image/jpeg' => [ 'imagecreatefromjpeg', 'truecolor', true,
 412                                 [ __CLASS__, 'imageJpegWrapper' ] ],
 413                         'image/png' => [ 'imagecreatefrompng', 'bits', false, 'imagepng' ],
 414                         'image/vnd.wap.wbmp' => [ 'imagecreatefromwbmp', 'palette', false, 'imagewbmp' ],
 415                         'image/xbm' => [ 'imagecreatefromxbm', 'palette', false, 'imagexbm' ],
 416                 ];
 417
 418                 if ( !isset( $typemap[$params['mimeType']] ) ) {
 419                         $err = 'Image type not supported';
 420                         wfDebug( "$err\n" );
 421                         $errMsg = wfMessage( 'thumbnail_image-type' )->text();
 422
 423                         return $this->getMediaTransformError( $params, $errMsg );
 424                 }
 425                 list( $loader, $colorStyle, $useQuality, $saveType ) = $typemap[$params['mimeType']];
 426
 427                 if ( !function_exists( $loader ) ) {
 428                         $err = "Incomplete GD library configuration: missing function $loader";
 429                         wfDebug( "$err\n" );
 430                         $errMsg = wfMessage( 'thumbnail_gd-library', $loader )->text();
 431
 432                         return $this->getMediaTransformError( $params, $errMsg );
 433                 }
 434
 435                 if ( !file_exists( $params['srcPath'] ) ) {
 436                         $err = "File seems to be missing: {$params['srcPath']}";
 437                         wfDebug( "$err\n" );
 438                         $errMsg = wfMessage( 'thumbnail_image-missing', $params['srcPath'] )->text();
 439
 440                         return $this->getMediaTransformError( $params, $errMsg );
 441                 }
 442
 443                 $src_image = call_user_func( $loader, $params['srcPath'] );
 444
 445                 $rotation = function_exists( 'imagerotate' ) && !isset( $params['disableRotation'] ) ?
 446                         $this->getRotation( $image ) :
 447                         0;
 448                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 449                 $dst_image = imagecreatetruecolor( $width, $height );
 450
 451                 // Initialise the destination image to transparent instead of
 452                 // the default solid black, to support PNG and GIF transparency nicely
 453                 $background = imagecolorallocate( $dst_image, 0, 0, 0 );
 454                 imagecolortransparent( $dst_image, $background );
 455                 imagealphablending( $dst_image, false );
 456
 457                 if ( $colorStyle == 'palette' ) {
 458                         // Don't resample for paletted GIF images.
 459                         // It may just uglify them, and completely breaks transparency.
 460                         imagecopyresized( $dst_image, $src_image,
 461                                 0, 0, 0, 0,
 462                                 $width, $height,
 463                                 imagesx( $src_image ), imagesy( $src_image ) );
 464                 } else {
 465                         imagecopyresampled( $dst_image, $src_image,
 466                                 0, 0, 0, 0,
 467                                 $width, $height,
 468                                 imagesx( $src_image ), imagesy( $src_image ) );
 469                 }
 470
 471                 if ( $rotation % 360 != 0 && $rotation % 90 == 0 ) {
 472                         $rot_image = imagerotate( $dst_image, $rotation, 0 );
 473                         imagedestroy( $dst_image );
 474                         $dst_image = $rot_image;
 475                 }
 476
 477                 imagesavealpha( $dst_image, true );
 478
 479                 $funcParams = [ $dst_image, $params['dstPath'] ];
 480                 if ( $useQuality && isset( $params['quality'] ) ) {
 481                         $funcParams[] = $params['quality'];
 482                 }
 483                 call_user_func_array( $saveType, $funcParams );
 484
 485                 imagedestroy( $dst_image );
 486                 imagedestroy( $src_image );
 487
 488                 return false; # No error
 489         }
 490
 491         /**
 492          * Callback for transformGd when transforming jpeg images.
 493          */
 494         // FIXME: transformImageMagick() & transformImageMagickExt() uses JPEG quality 80, here it's 95?
 495         static function imageJpegWrapper( $dst_image, $thumbPath, $quality = 95 ) {
 496                 imageinterlace( $dst_image );
 497                 imagejpeg( $dst_image, $thumbPath, $quality );
 498         }
 499
 500         /**
 501          * Returns whether the current scaler supports rotation (im and gd do)
 502          *
 503          * @return bool
 504          */
 505         public function canRotate() {
 506                 $scaler = $this->getScalerType( null, false );
 507                 switch ( $scaler ) {
 508                         case 'im':
 509                                 # ImageMagick supports autorotation
 510                                 return true;
 511                         case 'imext':
 512                                 # Imagick::rotateImage
 513                                 return true;
 514                         case 'gd':
 515                                 # GD's imagerotate function is used to rotate images, but not
 516                                 # all precompiled PHP versions have that function
 517                                 return function_exists( 'imagerotate' );
 518                         default:
 519                                 # Other scalers don't support rotation
 520                                 return false;
 521                 }
 522         }
 523
 524         /**
 525          * @see $wgEnableAutoRotation
 526          * @return bool Whether auto rotation is enabled
 527          */
 528         public function autoRotateEnabled() {
 529                 global $wgEnableAutoRotation;
 530
 531                 if ( $wgEnableAutoRotation === null ) {
 532                         // Only enable auto-rotation when we actually can
 533                         return $this->canRotate();
 534                 }
 535
 536                 return $wgEnableAutoRotation;
 537         }
 538
 539         /**
 540          * @param File $file
 541          * @param array $params Rotate parameters.
 542          *   'rotation' clockwise rotation in degrees, allowed are multiples of 90
 543          * @since 1.21
 544          * @return bool|MediaTransformError
 545          */
 546         public function rotate( $file, $params ) {
 547                 global $wgImageMagickConvertCommand;
 548
 549                 $rotation = ( $params['rotation'] + $this->getRotation( $file ) ) % 360;
 550                 $scene = false;
 551
 552                 $scaler = $this->getScalerType( null, false );
 553                 switch ( $scaler ) {
 554                         case 'im':
 555                                 $cmd = wfEscapeShellArg( $wgImageMagickConvertCommand ) . " " .
 556                                         wfEscapeShellArg( $this->escapeMagickInput( $params['srcPath'], $scene ) ) .
 557                                         " -rotate " . wfEscapeShellArg( "-$rotation" ) . " " .
 558                                         wfEscapeShellArg( $this->escapeMagickOutput( $params['dstPath'] ) );
 559                                 wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
 560                                 $retval = 0;
 561                                 $err = wfShellExecWithStderr( $cmd, $retval );
 562                                 if ( $retval !== 0 ) {
 563                                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 564
 565                                         return new MediaTransformError( 'thumbnail_error', 0, 0, $err );
 566                                 }
 567
 568                                 return false;
 569                         case 'imext':
 570                                 $im = new Imagick();
 571                                 $im->readImage( $params['srcPath'] );
 572                                 if ( !$im->rotateImage( new ImagickPixel( 'white' ), 360 - $rotation ) ) {
 573                                         return new MediaTransformError( 'thumbnail_error', 0, 0,
 574                                                 "Error rotating $rotation degrees" );
 575                                 }
 576                                 $result = $im->writeImage( $params['dstPath'] );
 577                                 if ( !$result ) {
 578                                         return new MediaTransformError( 'thumbnail_error', 0, 0,
 579                                                 "Unable to write image to {$params['dstPath']}" );
 580                                 }
 581
 582                                 return false;
 583                         default:
 584                                 return new MediaTransformError( 'thumbnail_error', 0, 0,
 585                                         "$scaler rotation not implemented" );
 586                 }
 587         }
 588 }