includes/media/BitmapHandler.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 use MediaWiki\Shell\Shell;
  25
  26 /**
  27  * Generic handler for bitmap images
  28  *
  29  * @ingroup Media
  30  */
  31 class BitmapHandler extends TransformationalImageHandler {
  32
  33         /**
  34          * Returns which scaler type should be used. Creates parent directories
  35          * for $dstPath and returns 'client' on error
  36          *
  37          * @param string $dstPath
  38          * @param bool $checkDstPath
  39          * @return string|Callable One of client, im, custom, gd, imext or an array( object, method )
  40          */
  41         protected function getScalerType( $dstPath, $checkDstPath = true ) {
  42                 global $wgUseImageResize, $wgUseImageMagick, $wgCustomConvertCommand;
  43
  44                 if ( !$dstPath && $checkDstPath ) {
  45                         # No output path available, client side scaling only
  46                         $scaler = 'client';
  47                 } elseif ( !$wgUseImageResize ) {
  48                         $scaler = 'client';
  49                 } elseif ( $wgUseImageMagick ) {
  50                         $scaler = 'im';
  51                 } elseif ( $wgCustomConvertCommand ) {
  52                         $scaler = 'custom';
  53                 } elseif ( function_exists( 'imagecreatetruecolor' ) ) {
  54                         $scaler = 'gd';
  55                 } elseif ( class_exists( 'Imagick' ) ) {
  56                         $scaler = 'imext';
  57                 } else {
  58                         $scaler = 'client';
  59                 }
  60
  61                 return $scaler;
  62         }
  63
  64         public function makeParamString( $params ) {
  65                 $res = parent::makeParamString( $params );
  66                 if ( isset( $params['interlace'] ) && $params['interlace'] ) {
  67                         return "interlaced-{$res}";
  68                 } else {
  69                         return $res;
  70                 }
  71         }
  72
  73         public function parseParamString( $str ) {
  74                 $remainder = preg_replace( '/^interlaced-/', '', $str );
  75                 $params = parent::parseParamString( $remainder );
  76                 if ( $params === false ) {
  77                         return false;
  78                 }
  79                 $params['interlace'] = $str !== $remainder;
  80                 return $params;
  81         }
  82
  83         public function validateParam( $name, $value ) {
  84                 if ( $name === 'interlace' ) {
  85                         return $value === false || $value === true;
  86                 } else {
  87                         return parent::validateParam( $name, $value );
  88                 }
  89         }
  90
  91         /**
  92          * @param File $image
  93          * @param array &$params
  94          * @return bool
  95          */
  96         public function normaliseParams( $image, &$params ) {
  97                 global $wgMaxInterlacingAreas;
  98                 if ( !parent::normaliseParams( $image, $params ) ) {
  99                         return false;
 100                 }
 101                 $mimeType = $image->getMimeType();
 102                 $interlace = isset( $params['interlace'] ) && $params['interlace']
 103                         && isset( $wgMaxInterlacingAreas[$mimeType] )
 104                         && $this->getImageArea( $image ) <= $wgMaxInterlacingAreas[$mimeType];
 105                 $params['interlace'] = $interlace;
 106                 return true;
 107         }
 108
 109         /**
 110          * Get ImageMagick subsampling factors for the target JPEG pixel format.
 111          *
 112          * @param string $pixelFormat one of 'yuv444', 'yuv422', 'yuv420'
 113          * @return array of string keys
 114          */
 115         protected function imageMagickSubsampling( $pixelFormat ) {
 116                 switch ( $pixelFormat ) {
 117                         case 'yuv444':
 118                                 return [ '1x1', '1x1', '1x1' ];
 119                         case 'yuv422':
 120                                 return [ '2x1', '1x1', '1x1' ];
 121                         case 'yuv420':
 122                                 return [ '2x2', '1x1', '1x1' ];
 123                         default:
 124                                 throw new MWException( 'Invalid pixel format for JPEG output' );
 125                 }
 126         }
 127
 128         /**
 129          * Transform an image using ImageMagick
 130          *
 131          * @param File $image File associated with this thumbnail
 132          * @param array $params Array with scaler params
 133          *
 134          * @return MediaTransformError|bool Error object if error occurred, false (=no error) otherwise
 135          */
 136         protected function transformImageMagick( $image, $params ) {
 137                 # use ImageMagick
 138                 global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea,
 139                         $wgImageMagickTempDir, $wgImageMagickConvertCommand, $wgJpegPixelFormat,
 140                         $wgJpegQuality;
 141
 142                 $quality = [];
 143                 $sharpen = [];
 144                 $scene = false;
 145                 $animation_pre = [];
 146                 $animation_post = [];
 147                 $decoderHint = [];
 148                 $subsampling = [];
 149
 150                 if ( $params['mimeType'] == 'image/jpeg' ) {
 151                         $qualityVal = isset( $params['quality'] ) ? (string)$params['quality'] : null;
 152                         $quality = [ '-quality', $qualityVal ?: (string)$wgJpegQuality ]; // 80% by default
 153                         if ( $params['interlace'] ) {
 154                                 $animation_post = [ '-interlace', 'JPEG' ];
 155                         }
 156                         # Sharpening, see T8193
 157                         if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 158                                 / ( $params['srcWidth'] + $params['srcHeight'] )
 159                                 < $wgSharpenReductionThreshold
 160                         ) {
 161                                 $sharpen = [ '-sharpen', $wgSharpenParameter ];
 162                         }
 163                         if ( version_compare( $this->getMagickVersion(), "6.5.6" ) >= 0 ) {
 164                                 // JPEG decoder hint to reduce memory, available since IM 6.5.6-2
 165                                 $decoderHint = [ '-define', "jpeg:size={$params['physicalDimensions']}" ];
 166                         }
 167                         if ( $wgJpegPixelFormat ) {
 168                                 $factors = $this->imageMagickSubsampling( $wgJpegPixelFormat );
 169                                 $subsampling = [ '-sampling-factor', implode( ',', $factors ) ];
 170                         }
 171                 } elseif ( $params['mimeType'] == 'image/png' ) {
 172                         $quality = [ '-quality', '95' ]; // zlib 9, adaptive filtering
 173                         if ( $params['interlace'] ) {
 174                                 $animation_post = [ '-interlace', 'PNG' ];
 175                         }
 176                 } elseif ( $params['mimeType'] == 'image/webp' ) {
 177                         $quality = [ '-quality', '95' ]; // zlib 9, adaptive filtering
 178                 } elseif ( $params['mimeType'] == 'image/gif' ) {
 179                         if ( $this->getImageArea( $image ) > $wgMaxAnimatedGifArea ) {
 180                                 // Extract initial frame only; we're so big it'll
 181                                 // be a total drag. :P
 182                                 $scene = 0;
 183                         } elseif ( $this->isAnimatedImage( $image ) ) {
 184                                 // Coalesce is needed to scale animated GIFs properly (T3017).
 185                                 $animation_pre = [ '-coalesce' ];
 186                                 // We optimize the output, but -optimize is broken,
 187                                 // use optimizeTransparency instead (T13822)
 188                                 if ( version_compare( $this->getMagickVersion(), "6.3.5" ) >= 0 ) {
 189                                         $animation_post = [ '-fuzz', '5%', '-layers', 'optimizeTransparency' ];
 190                                 }
 191                         }
 192                         if ( $params['interlace'] && version_compare( $this->getMagickVersion(), "6.3.4" ) >= 0
 193                                 && !$this->isAnimatedImage( $image ) ) { // interlacing animated GIFs is a bad idea
 194                                 $animation_post[] = '-interlace';
 195                                 $animation_post[] = 'GIF';
 196                         }
 197                 } elseif ( $params['mimeType'] == 'image/x-xcf' ) {
 198                         // Before merging layers, we need to set the background
 199                         // to be transparent to preserve alpha, as -layers merge
 200                         // merges all layers on to a canvas filled with the
 201                         // background colour. After merging we reset the background
 202                         // to be white for the default background colour setting
 203                         // in the PNG image (which is used in old IE)
 204                         $animation_pre = [
 205                                 '-background', 'transparent',
 206                                 '-layers', 'merge',
 207                                 '-background', 'white',
 208                         ];
 209                         Wikimedia\suppressWarnings();
 210                         $xcfMeta = unserialize( $image->getMetadata() );
 211                         Wikimedia\restoreWarnings();
 212                         if ( $xcfMeta
 213                                 && isset( $xcfMeta['colorType'] )
 214                                 && $xcfMeta['colorType'] === 'greyscale-alpha'
 215                                 && version_compare( $this->getMagickVersion(), "6.8.9-3" ) < 0
 216                         ) {
 217                                 // T68323 - Greyscale images not rendered properly.
 218                                 // So only take the "red" channel.
 219                                 $channelOnly = [ '-channel', 'R', '-separate' ];
 220                                 $animation_pre = array_merge( $animation_pre, $channelOnly );
 221                         }
 222                 }
 223
 224                 // Use one thread only, to avoid deadlock bugs on OOM
 225                 $env = [ 'OMP_NUM_THREADS' => 1 ];
 226                 if ( strval( $wgImageMagickTempDir ) !== '' ) {
 227                         $env['MAGICK_TMPDIR'] = $wgImageMagickTempDir;
 228                 }
 229
 230                 $rotation = isset( $params['disableRotation'] ) ? 0 : $this->getRotation( $image );
 231                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 232
 233                 $cmd = Shell::escape( ...array_merge(
 234                         [ $wgImageMagickConvertCommand ],
 235                         $quality,
 236                         // Specify white background color, will be used for transparent images
 237                         // in Internet Explorer/Windows instead of default black.
 238                         [ '-background', 'white' ],
 239                         $decoderHint,
 240                         [ $this->escapeMagickInput( $params['srcPath'], $scene ) ],
 241                         $animation_pre,
 242                         // For the -thumbnail option a "!" is needed to force exact size,
 243                         // or ImageMagick may decide your ratio is wrong and slice off
 244                         // a pixel.
 245                         [ '-thumbnail', "{$width}x{$height}!" ],
 246                         // Add the source url as a comment to the thumb, but don't add the flag if there's no comment
 247                         ( $params['comment'] !== ''
 248                                 ? [ '-set', 'comment', $this->escapeMagickProperty( $params['comment'] ) ]
 249                                 : [] ),
 250                         // T108616: Avoid exposure of local file path
 251                         [ '+set', 'Thumb::URI' ],
 252                         [ '-depth', 8 ],
 253                         $sharpen,
 254                         [ '-rotate', "-$rotation" ],
 255                         $subsampling,
 256                         $animation_post,
 257                         [ $this->escapeMagickOutput( $params['dstPath'] ) ] ) );
 258
 259                 wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
 260                 $retval = 0;
 261                 $err = wfShellExecWithStderr( $cmd, $retval, $env );
 262
 263                 if ( $retval !== 0 ) {
 264                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 265
 266                         return $this->getMediaTransformError( $params, "$err\nError code: $retval" );
 267                 }
 268
 269                 return false; # No error
 270         }
 271
 272         /**
 273          * Transform an image using the Imagick PHP extension
 274          *
 275          * @param File $image File associated with this thumbnail
 276          * @param array $params Array with scaler params
 277          *
 278          * @return MediaTransformError Error|bool object if error occurred, false (=no error) otherwise
 279          */
 280         protected function transformImageMagickExt( $image, $params ) {
 281                 global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea,
 282                         $wgJpegPixelFormat, $wgJpegQuality;
 283
 284                 try {
 285                         $im = new Imagick();
 286                         $im->readImage( $params['srcPath'] );
 287
 288                         if ( $params['mimeType'] == 'image/jpeg' ) {
 289                                 // Sharpening, see T8193
 290                                 if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 291                                         / ( $params['srcWidth'] + $params['srcHeight'] )
 292                                         < $wgSharpenReductionThreshold
 293                                 ) {
 294                                         // Hack, since $wgSharpenParameter is written specifically for the command line convert
 295                                         list( $radius, $sigma ) = explode( 'x', $wgSharpenParameter );
 296                                         $im->sharpenImage( $radius, $sigma );
 297                                 }
 298                                 $qualityVal = isset( $params['quality'] ) ? (string)$params['quality'] : null;
 299                                 $im->setCompressionQuality( $qualityVal ?: $wgJpegQuality );
 300                                 if ( $params['interlace'] ) {
 301                                         $im->setInterlaceScheme( Imagick::INTERLACE_JPEG );
 302                                 }
 303                                 if ( $wgJpegPixelFormat ) {
 304                                         $factors = $this->imageMagickSubsampling( $wgJpegPixelFormat );
 305                                         $im->setSamplingFactors( $factors );
 306                                 }
 307                         } elseif ( $params['mimeType'] == 'image/png' ) {
 308                                 $im->setCompressionQuality( 95 );
 309                                 if ( $params['interlace'] ) {
 310                                         $im->setInterlaceScheme( Imagick::INTERLACE_PNG );
 311                                 }
 312                         } elseif ( $params['mimeType'] == 'image/gif' ) {
 313                                 if ( $this->getImageArea( $image ) > $wgMaxAnimatedGifArea ) {
 314                                         // Extract initial frame only; we're so big it'll
 315                                         // be a total drag. :P
 316                                         $im->setImageScene( 0 );
 317                                 } elseif ( $this->isAnimatedImage( $image ) ) {
 318                                         // Coalesce is needed to scale animated GIFs properly (T3017).
 319                                         $im = $im->coalesceImages();
 320                                 }
 321                                 // GIF interlacing is only available since 6.3.4
 322                                 $v = Imagick::getVersion();
 323                                 preg_match( '/ImageMagick ([0-9]+\.[0-9]+\.[0-9]+)/', $v['versionString'], $v );
 324
 325                                 if ( $params['interlace'] && version_compare( $v[1], '6.3.4' ) >= 0 ) {
 326                                         $im->setInterlaceScheme( Imagick::INTERLACE_GIF );
 327                                 }
 328                         }
 329
 330                         $rotation = isset( $params['disableRotation'] ) ? 0 : $this->getRotation( $image );
 331                         list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 332
 333                         $im->setImageBackgroundColor( new ImagickPixel( 'white' ) );
 334
 335                         // Call Imagick::thumbnailImage on each frame
 336                         foreach ( $im as $i => $frame ) {
 337                                 if ( !$frame->thumbnailImage( $width, $height, /* fit */ false ) ) {
 338                                         return $this->getMediaTransformError( $params, "Error scaling frame $i" );
 339                                 }
 340                         }
 341                         $im->setImageDepth( 8 );
 342
 343                         if ( $rotation && !$im->rotateImage( new ImagickPixel( 'white' ), 360 - $rotation ) ) {
 344                                 return $this->getMediaTransformError( $params, "Error rotating $rotation degrees" );
 345                         }
 346
 347                         if ( $this->isAnimatedImage( $image ) ) {
 348                                 wfDebug( __METHOD__ . ": Writing animated thumbnail\n" );
 349                                 // This is broken somehow... can't find out how to fix it
 350                                 $result = $im->writeImages( $params['dstPath'], true );
 351                         } else {
 352                                 $result = $im->writeImage( $params['dstPath'] );
 353                         }
 354                         if ( !$result ) {
 355                                 return $this->getMediaTransformError( $params,
 356                                         "Unable to write thumbnail to {$params['dstPath']}" );
 357                         }
 358                 } catch ( ImagickException $e ) {
 359                         return $this->getMediaTransformError( $params, $e->getMessage() );
 360                 }
 361
 362                 return false;
 363         }
 364
 365         /**
 366          * Transform an image using a custom command
 367          *
 368          * @param File $image File associated with this thumbnail
 369          * @param array $params Array with scaler params
 370          *
 371          * @return MediaTransformError Error|bool object if error occurred, false (=no error) otherwise
 372          */
 373         protected function transformCustom( $image, $params ) {
 374                 # Use a custom convert command
 375                 global $wgCustomConvertCommand;
 376
 377                 # Variables: %s %d %w %h
 378                 $src = Shell::escape( $params['srcPath'] );
 379                 $dst = Shell::escape( $params['dstPath'] );
 380                 $cmd = $wgCustomConvertCommand;
 381                 $cmd = str_replace( '%s', $src, str_replace( '%d', $dst, $cmd ) ); # Filenames
 382                 $cmd = str_replace( '%h', Shell::escape( $params['physicalHeight'] ),
 383                         str_replace( '%w', Shell::escape( $params['physicalWidth'] ), $cmd ) ); # Size
 384                 wfDebug( __METHOD__ . ": Running custom convert command $cmd\n" );
 385                 $retval = 0;
 386                 $err = wfShellExecWithStderr( $cmd, $retval );
 387
 388                 if ( $retval !== 0 ) {
 389                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 390
 391                         return $this->getMediaTransformError( $params, $err );
 392                 }
 393
 394                 return false; # No error
 395         }
 396
 397         /**
 398          * Transform an image using the built in GD library
 399          *
 400          * @param File $image File associated with this thumbnail
 401          * @param array $params Array with scaler params
 402          *
 403          * @return MediaTransformError|bool Error object if error occurred, false (=no error) otherwise
 404          */
 405         protected function transformGd( $image, $params ) {
 406                 # Use PHP's builtin GD library functions.
 407                 # First find out what kind of file this is, and select the correct
 408                 # input routine for this.
 409
 410                 $typemap = [
 411                         'image/gif' => [ 'imagecreatefromgif', 'palette', false, 'imagegif' ],
 412                         'image/jpeg' => [ 'imagecreatefromjpeg', 'truecolor', true,
 413                                 [ __CLASS__, 'imageJpegWrapper' ] ],
 414                         'image/png' => [ 'imagecreatefrompng', 'bits', false, 'imagepng' ],
 415                         'image/vnd.wap.wbmp' => [ 'imagecreatefromwbmp', 'palette', false, 'imagewbmp' ],
 416                         'image/xbm' => [ 'imagecreatefromxbm', 'palette', false, 'imagexbm' ],
 417                 ];
 418
 419                 if ( !isset( $typemap[$params['mimeType']] ) ) {
 420                         $err = 'Image type not supported';
 421                         wfDebug( "$err\n" );
 422                         $errMsg = wfMessage( 'thumbnail_image-type' )->text();
 423
 424                         return $this->getMediaTransformError( $params, $errMsg );
 425                 }
 426                 list( $loader, $colorStyle, $useQuality, $saveType ) = $typemap[$params['mimeType']];
 427
 428                 if ( !function_exists( $loader ) ) {
 429                         $err = "Incomplete GD library configuration: missing function $loader";
 430                         wfDebug( "$err\n" );
 431                         $errMsg = wfMessage( 'thumbnail_gd-library', $loader )->text();
 432
 433                         return $this->getMediaTransformError( $params, $errMsg );
 434                 }
 435
 436                 if ( !file_exists( $params['srcPath'] ) ) {
 437                         $err = "File seems to be missing: {$params['srcPath']}";
 438                         wfDebug( "$err\n" );
 439                         $errMsg = wfMessage( 'thumbnail_image-missing', $params['srcPath'] )->text();
 440
 441                         return $this->getMediaTransformError( $params, $errMsg );
 442                 }
 443
 444                 if ( filesize( $params['srcPath'] ) === 0 ) {
 445                         $err = "Image file size seems to be zero.";
 446                         wfDebug( "$err\n" );
 447                         $errMsg = wfMessage( 'thumbnail_image-size-zero', $params['srcPath'] )->text();
 448
 449                         return $this->getMediaTransformError( $params, $errMsg );
 450                 }
 451
 452                 $src_image = $loader( $params['srcPath'] );
 453
 454                 $rotation = function_exists( 'imagerotate' ) && !isset( $params['disableRotation'] ) ?
 455                         $this->getRotation( $image ) :
 456                         0;
 457                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 458                 $dst_image = imagecreatetruecolor( $width, $height );
 459
 460                 // Initialise the destination image to transparent instead of
 461                 // the default solid black, to support PNG and GIF transparency nicely
 462                 $background = imagecolorallocate( $dst_image, 0, 0, 0 );
 463                 imagecolortransparent( $dst_image, $background );
 464                 imagealphablending( $dst_image, false );
 465
 466                 if ( $colorStyle == 'palette' ) {
 467                         // Don't resample for paletted GIF images.
 468                         // It may just uglify them, and completely breaks transparency.
 469                         imagecopyresized( $dst_image, $src_image,
 470                                 0, 0, 0, 0,
 471                                 $width, $height,
 472                                 imagesx( $src_image ), imagesy( $src_image ) );
 473                 } else {
 474                         imagecopyresampled( $dst_image, $src_image,
 475                                 0, 0, 0, 0,
 476                                 $width, $height,
 477                                 imagesx( $src_image ), imagesy( $src_image ) );
 478                 }
 479
 480                 if ( $rotation % 360 != 0 && $rotation % 90 == 0 ) {
 481                         $rot_image = imagerotate( $dst_image, $rotation, 0 );
 482                         imagedestroy( $dst_image );
 483                         $dst_image = $rot_image;
 484                 }
 485
 486                 imagesavealpha( $dst_image, true );
 487
 488                 $funcParams = [ $dst_image, $params['dstPath'] ];
 489                 if ( $useQuality && isset( $params['quality'] ) ) {
 490                         $funcParams[] = $params['quality'];
 491                 }
 492                 $saveType( ...$funcParams );
 493
 494                 imagedestroy( $dst_image );
 495                 imagedestroy( $src_image );
 496
 497                 return false; # No error
 498         }
 499
 500         /**
 501          * Callback for transformGd when transforming jpeg images.
 502          *
 503          * @param resource $dst_image Image resource of the original image
 504          * @param string $thumbPath File path to write the thumbnail image to
 505          * @param int|null $quality Quality of the thumbnail from 1-100,
 506          *    or null to use default quality.
 507          */
 508         static function imageJpegWrapper( $dst_image, $thumbPath, $quality = null ) {
 509                 global $wgJpegQuality;
 510
 511                 if ( $quality === null ) {
 512                         $quality = $wgJpegQuality;
 513                 }
 514
 515                 imageinterlace( $dst_image );
 516                 imagejpeg( $dst_image, $thumbPath, $quality );
 517         }
 518
 519         /**
 520          * Returns whether the current scaler supports rotation (im and gd do)
 521          *
 522          * @return bool
 523          */
 524         public function canRotate() {
 525                 $scaler = $this->getScalerType( null, false );
 526                 switch ( $scaler ) {
 527                         case 'im':
 528                                 # ImageMagick supports autorotation
 529                                 return true;
 530                         case 'imext':
 531                                 # Imagick::rotateImage
 532                                 return true;
 533                         case 'gd':
 534                                 # GD's imagerotate function is used to rotate images, but not
 535                                 # all precompiled PHP versions have that function
 536                                 return function_exists( 'imagerotate' );
 537                         default:
 538                                 # Other scalers don't support rotation
 539                                 return false;
 540                 }
 541         }
 542
 543         /**
 544          * @see $wgEnableAutoRotation
 545          * @return bool Whether auto rotation is enabled
 546          */
 547         public function autoRotateEnabled() {
 548                 global $wgEnableAutoRotation;
 549
 550                 if ( $wgEnableAutoRotation === null ) {
 551                         // Only enable auto-rotation when we actually can
 552                         return $this->canRotate();
 553                 }
 554
 555                 return $wgEnableAutoRotation;
 556         }
 557
 558         /**
 559          * @param File $file
 560          * @param array $params Rotate parameters.
 561          *   'rotation' clockwise rotation in degrees, allowed are multiples of 90
 562          * @since 1.21
 563          * @return bool|MediaTransformError
 564          */
 565         public function rotate( $file, $params ) {
 566                 global $wgImageMagickConvertCommand;
 567
 568                 $rotation = ( $params['rotation'] + $this->getRotation( $file ) ) % 360;
 569                 $scene = false;
 570
 571                 $scaler = $this->getScalerType( null, false );
 572                 switch ( $scaler ) {
 573                         case 'im':
 574                                 $cmd = Shell::escape( $wgImageMagickConvertCommand ) . " " .
 575                                         Shell::escape( $this->escapeMagickInput( $params['srcPath'], $scene ) ) .
 576                                         " -rotate " . Shell::escape( "-$rotation" ) . " " .
 577                                         Shell::escape( $this->escapeMagickOutput( $params['dstPath'] ) );
 578                                 wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
 579                                 $retval = 0;
 580                                 $err = wfShellExecWithStderr( $cmd, $retval );
 581                                 if ( $retval !== 0 ) {
 582                                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 583
 584                                         return new MediaTransformError( 'thumbnail_error', 0, 0, $err );
 585                                 }
 586
 587                                 return false;
 588                         case 'imext':
 589                                 $im = new Imagick();
 590                                 $im->readImage( $params['srcPath'] );
 591                                 if ( !$im->rotateImage( new ImagickPixel( 'white' ), 360 - $rotation ) ) {
 592                                         return new MediaTransformError( 'thumbnail_error', 0, 0,
 593                                                 "Error rotating $rotation degrees" );
 594                                 }
 595                                 $result = $im->writeImage( $params['dstPath'] );
 596                                 if ( !$result ) {
 597                                         return new MediaTransformError( 'thumbnail_error', 0, 0,
 598                                                 "Unable to write image to {$params['dstPath']}" );
 599                                 }
 600
 601                                 return false;
 602                         default:
 603                                 return new MediaTransformError( 'thumbnail_error', 0, 0,
 604                                         "$scaler rotation not implemented" );
 605                 }
 606         }
 607 }