includes/media/Bitmap.php

   1 <?php
   2 /**
   3  * Generic handler for bitmap images
   4  *
   5  * @file
   6  * @ingroup Media
   7  */
   8
   9 /**
  10  * Generic handler for bitmap images
  11  *
  12  * @ingroup Media
  13  */
  14 class BitmapHandler extends ImageHandler {
  15         function normaliseParams( $image, &$params ) {
  16                 global $wgMaxImageArea;
  17                 if ( !parent::normaliseParams( $image, $params ) ) {
  18                         return false;
  19                 }
  20
  21                 $mimeType = $image->getMimeType();
  22                 $srcWidth = $image->getWidth( $params['page'] );
  23                 $srcHeight = $image->getHeight( $params['page'] );
  24
  25                 # Don't make an image bigger than the source
  26                 $params['physicalWidth'] = $params['width'];
  27                 $params['physicalHeight'] = $params['height'];
  28
  29                 if ( $params['physicalWidth'] >= $srcWidth ) {
  30                         $params['physicalWidth'] = $srcWidth;
  31                         $params['physicalHeight'] = $srcHeight;
  32                         # Skip scaling limit checks if no scaling is required
  33                         if( !$image->mustRender() )
  34                                 return true;
  35                 }
  36
  37                 # Don't thumbnail an image so big that it will fill hard drives and send servers into swap
  38                 # JPEG has the handy property of allowing thumbnailing without full decompression, so we make
  39                 # an exception for it.
  40                 if ( $mimeType !== 'image/jpeg' &&
  41                         $srcWidth * $srcHeight > $wgMaxImageArea )
  42                 {
  43                         return false;
  44                 }
  45
  46                 return true;
  47         }
  48
  49
  50         // Function that returns the number of pixels to be thumbnailed.
  51         // Intended for animated GIFs to multiply by the number of frames.
  52         function getImageArea( $image, $width, $height ) {
  53                 return $width * $height;
  54         }
  55
  56         function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
  57                 global $wgUseImageMagick, $wgImageMagickConvertCommand, $wgImageMagickTempDir;
  58                 global $wgCustomConvertCommand, $wgUseImageResize;
  59                 global $wgSharpenParameter, $wgSharpenReductionThreshold;
  60                 global $wgMaxAnimatedGifArea;
  61
  62                 if ( !$this->normaliseParams( $image, $params ) ) {
  63                         return new TransformParameterError( $params );
  64                 }
  65                 $physicalWidth = $params['physicalWidth'];
  66                 $physicalHeight = $params['physicalHeight'];
  67                 $clientWidth = $params['width'];
  68                 $clientHeight = $params['height'];
  69                 $comment = isset( $params['descriptionUrl'] ) ? "File source: ". $params['descriptionUrl'] : '';
  70                 $srcWidth = $image->getWidth();
  71                 $srcHeight = $image->getHeight();
  72                 $mimeType = $image->getMimeType();
  73                 $srcPath = $image->getPath();
  74                 $retval = 0;
  75                 wfDebug( __METHOD__.": creating {$physicalWidth}x{$physicalHeight} thumbnail at $dstPath\n" );
  76
  77                 if ( !$image->mustRender() && $physicalWidth == $srcWidth && $physicalHeight == $srcHeight ) {
  78                         # normaliseParams (or the user) wants us to return the unscaled image
  79                         wfDebug( __METHOD__.": returning unscaled image\n" );
  80                         return new ThumbnailImage( $image, $image->getURL(), $clientWidth, $clientHeight, $srcPath );
  81                 }
  82
  83                 if ( !$dstPath ) {
  84                         // No output path available, client side scaling only
  85                         $scaler = 'client';
  86                 } elseif( !$wgUseImageResize ) {
  87                         $scaler = 'client';
  88                 } elseif ( $wgUseImageMagick ) {
  89                         $scaler = 'im';
  90                 } elseif ( $wgCustomConvertCommand ) {
  91                         $scaler = 'custom';
  92                 } elseif ( function_exists( 'imagecreatetruecolor' ) ) {
  93                         $scaler = 'gd';
  94                 } else {
  95                         $scaler = 'client';
  96                 }
  97                 wfDebug( __METHOD__.": scaler $scaler\n" );
  98
  99                 if ( $scaler == 'client' ) {
 100                         # Client-side image scaling, use the source URL
 101                         # Using the destination URL in a TRANSFORM_LATER request would be incorrect
 102                         return new ThumbnailImage( $image, $image->getURL(), $clientWidth, $clientHeight, $srcPath );
 103                 }
 104
 105                 if ( $flags & self::TRANSFORM_LATER ) {
 106                         wfDebug( __METHOD__.": Transforming later per flags.\n" );
 107                         return new ThumbnailImage( $image, $dstUrl, $clientWidth, $clientHeight, $dstPath );
 108                 }
 109
 110                 if ( !wfMkdirParents( dirname( $dstPath ) ) ) {
 111                         wfDebug( __METHOD__.": Unable to create thumbnail destination directory, falling back to client scaling\n" );
 112                         return new ThumbnailImage( $image, $image->getURL(), $clientWidth, $clientHeight, $srcPath );
 113                 }
 114
 115                 if ( $scaler == 'im' ) {
 116                         # use ImageMagick
 117
 118                         $quality = '';
 119                         $sharpen = '';
 120                         $scene = false;
 121                         $animation = '';
 122                         if ( $mimeType == 'image/jpeg' ) {
 123                                 $quality = "-quality 80"; // 80%
 124                                 # Sharpening, see bug 6193
 125                                 if ( ( $physicalWidth + $physicalHeight ) / ( $srcWidth + $srcHeight ) < $wgSharpenReductionThreshold ) {
 126                                         $sharpen = "-sharpen " . wfEscapeShellArg( $wgSharpenParameter );
 127                                 }
 128                         } elseif ( $mimeType == 'image/png' ) {
 129                                 $quality = "-quality 95"; // zlib 9, adaptive filtering
 130                         } elseif( $mimeType == 'image/gif' ) {
 131                                 if( $this->getImageArea( $image, $srcWidth, $srcHeight ) > $wgMaxAnimatedGifArea ) {
 132                                         // Extract initial frame only; we're so big it'll
 133                                         // be a total drag. :P
 134                                         $scene = 0;
 135                                 } else {
 136                                         // Coalesce is needed to scale animated GIFs properly (bug 1017).
 137                                         $animation = ' -coalesce ';
 138                                 }
 139                         }
 140
 141                         if ( strval( $wgImageMagickTempDir ) !== '' ) {
 142                                 $tempEnv = 'MAGICK_TMPDIR=' . wfEscapeShellArg( $wgImageMagickTempDir ) . ' ';
 143                         } else {
 144                                 $tempEnv = '';
 145                         }
 146
 147                         # Specify white background color, will be used for transparent images
 148                         # in Internet Explorer/Windows instead of default black.
 149
 150                         # Note, we specify "-size {$physicalWidth}" and NOT "-size {$physicalWidth}x{$physicalHeight}".
 151                         # It seems that ImageMagick has a bug wherein it produces thumbnails of
 152                         # the wrong size in the second case.
 153
 154                         $cmd  =
 155                                 $tempEnv .
 156                                 wfEscapeShellArg( $wgImageMagickConvertCommand ) .
 157                                 " {$quality} -background white -size {$physicalWidth} ".
 158                                 wfEscapeShellArg( $this->escapeMagickInput( $srcPath, $scene ) ) .
 159                                 $animation .
 160                                 // For the -resize option a "!" is needed to force exact size,
 161                                 // or ImageMagick may decide your ratio is wrong and slice off
 162                                 // a pixel.
 163                                 " -thumbnail " . wfEscapeShellArg( "{$physicalWidth}x{$physicalHeight}!" ) .
 164                                 // Add the source url as a comment to the thumb.
 165                                 " -set comment " . wfEscapeShellArg( $this->escapeMagickProperty( $comment ) ) .
 166                                 " -depth 8 $sharpen " .
 167                                 wfEscapeShellArg( $this->escapeMagickOutput( $dstPath ) ) . " 2>&1";
 168                         wfDebug( __METHOD__.": running ImageMagick: $cmd\n" );
 169                         wfProfileIn( 'convert' );
 170                         $err = wfShellExec( $cmd, $retval );
 171                         wfProfileOut( 'convert' );
 172                 } elseif( $scaler == 'custom' ) {
 173                         # Use a custom convert command
 174                         # Variables: %s %d %w %h
 175                         $src = wfEscapeShellArg( $srcPath );
 176                         $dst = wfEscapeShellArg( $dstPath );
 177                         $cmd = $wgCustomConvertCommand;
 178                         $cmd = str_replace( '%s', $src, str_replace( '%d', $dst, $cmd ) ); # Filenames
 179                         $cmd = str_replace( '%h', $physicalHeight, str_replace( '%w', $physicalWidth, $cmd ) ); # Size
 180                         wfDebug( __METHOD__.": Running custom convert command $cmd\n" );
 181                         wfProfileIn( 'convert' );
 182                         $err = wfShellExec( $cmd, $retval );
 183                         wfProfileOut( 'convert' );
 184                 } else /* $scaler == 'gd' */ {
 185                         # Use PHP's builtin GD library functions.
 186                         #
 187                         # First find out what kind of file this is, and select the correct
 188                         # input routine for this.
 189
 190                         $typemap = array(
 191                                 'image/gif'          => array( 'imagecreatefromgif',  'palette',   'imagegif'  ),
 192                                 'image/jpeg'         => array( 'imagecreatefromjpeg', 'truecolor', array( __CLASS__, 'imageJpegWrapper' ) ),
 193                                 'image/png'          => array( 'imagecreatefrompng',  'bits',      'imagepng'  ),
 194                                 'image/vnd.wap.wbmp' => array( 'imagecreatefromwbmp', 'palette',   'imagewbmp'  ),
 195                                 'image/xbm'          => array( 'imagecreatefromxbm',  'palette',   'imagexbm'  ),
 196                         );
 197                         if( !isset( $typemap[$mimeType] ) ) {
 198                                 $err = 'Image type not supported';
 199                                 wfDebug( "$err\n" );
 200                                 $errMsg = wfMsg ( 'thumbnail_image-type' );
 201                                 return new MediaTransformError( 'thumbnail_error', $clientWidth, $clientHeight, $errMsg );
 202                         }
 203                         list( $loader, $colorStyle, $saveType ) = $typemap[$mimeType];
 204
 205                         if( !function_exists( $loader ) ) {
 206                                 $err = "Incomplete GD library configuration: missing function $loader";
 207                                 wfDebug( "$err\n" );
 208                                 $errMsg = wfMsg ( 'thumbnail_gd-library', $loader );
 209                                 return new MediaTransformError( 'thumbnail_error', $clientWidth, $clientHeight, $errMsg );
 210                         }
 211
 212                         if ( !file_exists( $srcPath ) ) {
 213                                 $err = "File seems to be missing: $srcPath";
 214                                 wfDebug( "$err\n" );
 215                                 $errMsg = wfMsg ( 'thumbnail_image-missing', $srcPath );
 216                                 return new MediaTransformError( 'thumbnail_error', $clientWidth, $clientHeight, $errMsg );
 217                         }
 218
 219                         $src_image = call_user_func( $loader, $srcPath );
 220                         $dst_image = imagecreatetruecolor( $physicalWidth, $physicalHeight );
 221
 222                         // Initialise the destination image to transparent instead of
 223                         // the default solid black, to support PNG and GIF transparency nicely
 224                         $background = imagecolorallocate( $dst_image, 0, 0, 0 );
 225                         imagecolortransparent( $dst_image, $background );
 226                         imagealphablending( $dst_image, false );
 227
 228                         if( $colorStyle == 'palette' ) {
 229                                 // Don't resample for paletted GIF images.
 230                                 // It may just uglify them, and completely breaks transparency.
 231                                 imagecopyresized( $dst_image, $src_image,
 232                                         0,0,0,0,
 233                                         $physicalWidth, $physicalHeight, imagesx( $src_image ), imagesy( $src_image ) );
 234                         } else {
 235                                 imagecopyresampled( $dst_image, $src_image,
 236                                         0,0,0,0,
 237                                         $physicalWidth, $physicalHeight, imagesx( $src_image ), imagesy( $src_image ) );
 238                         }
 239
 240                         imagesavealpha( $dst_image, true );
 241
 242                         call_user_func( $saveType, $dst_image, $dstPath );
 243                         imagedestroy( $dst_image );
 244                         imagedestroy( $src_image );
 245                         $retval = 0;
 246                 }
 247
 248                 $removed = $this->removeBadFile( $dstPath, $retval );
 249                 if ( $retval != 0 || $removed ) {
 250                         wfDebugLog( 'thumbnail',
 251                                 sprintf( 'thumbnail failed on %s: error %d "%s" from "%s"',
 252                                         wfHostname(), $retval, trim($err), $cmd ) );
 253                         return new MediaTransformError( 'thumbnail_error', $clientWidth, $clientHeight, $err );
 254                 } else {
 255                         return new ThumbnailImage( $image, $dstUrl, $clientWidth, $clientHeight, $dstPath );
 256                 }
 257         }
 258
 259         /**
 260          * Escape a string for ImageMagick's property input (e.g. -set -comment)
 261          * See InterpretImageProperties() in magick/property.c
 262          */
 263         function escapeMagickProperty( $s ) {
 264                 // Double the backslashes
 265                 $s = str_replace( '\\', '\\\\', $s );
 266                 // Double the percents
 267                 $s = str_replace( '%', '%%', $s );
 268                 // Escape initial - or @
 269                 if ( strlen( $s ) > 0 && ( $s[0] === '-' || $s[0] === '@' ) ) {
 270                         $s = '\\' . $s;
 271                 }
 272                 return $s;
 273         }
 274
 275         /**
 276          * Escape a string for ImageMagick's input filenames. See ExpandFilenames()
 277          * and GetPathComponent() in magick/utility.c.
 278          *
 279          * This won't work with an initial ~ or @, so input files should be prefixed
 280          * with the directory name.
 281          *
 282          * Glob character unescaping is broken in ImageMagick before 6.6.1-5, but
 283          * it's broken in a way that doesn't involve trying to convert every file
 284          * in a directory, so we're better off escaping and waiting for the bugfix
 285          * to filter down to users.
 286          *
 287          * @param $path string The file path
 288          * @param $scene string The scene specification, or false if there is none
 289          */
 290         function escapeMagickInput( $path, $scene = false ) {
 291                 # Die on initial metacharacters (caller should prepend path)
 292                 $firstChar = substr( $path, 0, 1 );
 293                 if ( $firstChar === '~' || $firstChar === '@' ) {
 294                         throw new MWException( __METHOD__.': cannot escape this path name' );
 295                 }
 296
 297                 # Escape glob chars
 298                 $path = preg_replace( '/[*?\[\]{}]/', '\\\\\0', $path );
 299
 300                 return $this->escapeMagickPath( $path, $scene );
 301         }
 302
 303         /**
 304          * Escape a string for ImageMagick's output filename. See
 305          * InterpretImageFilename() in magick/image.c.
 306          */
 307         function escapeMagickOutput( $path, $scene = false ) {
 308                 $path = str_replace( '%', '%%', $path );
 309                 return $this->escapeMagickPath( $path, $scene );
 310         }
 311
 312         /**
 313          * Armour a string against ImageMagick's GetPathComponent(). This is a
 314          * helper function for escapeMagickInput() and escapeMagickOutput().
 315          *
 316          * @param $path string The file path
 317          * @param $scene string The scene specification, or false if there is none
 318          */
 319         protected function escapeMagickPath( $path, $scene = false ) {
 320                 # Die on format specifiers (other than drive letters). The regex is
 321                 # meant to match all the formats you get from "convert -list format"
 322                 if ( preg_match( '/^([a-zA-Z0-9-]+):/', $path, $m ) ) {
 323                         if ( wfIsWindows() && is_dir( $m[0] ) ) {
 324                                 // OK, it's a drive letter
 325                                 // ImageMagick has a similar exception, see IsMagickConflict()
 326                         } else {
 327                                 throw new MWException( __METHOD__.': unexpected colon character in path name' );
 328                         }
 329                 }
 330
 331                 # If there are square brackets, add a do-nothing scene specification
 332                 # to force a literal interpretation
 333                 if ( $scene === false ) {
 334                         if ( strpos( $path, '[' ) !== false ) {
 335                                 $path .= '[0--1]';
 336                         }
 337                 } else {
 338                         $path .= "[$scene]";
 339                 }
 340                 return $path;
 341         }
 342
 343         static function imageJpegWrapper( $dst_image, $thumbPath ) {
 344                 imageinterlace( $dst_image );
 345                 imagejpeg( $dst_image, $thumbPath, 95 );
 346         }
 347
 348
 349         function getMetadata( $image, $filename ) {
 350                 global $wgShowEXIF;
 351                 if( $wgShowEXIF && file_exists( $filename ) ) {
 352                         $exif = new Exif( $filename );
 353                         $data = $exif->getFilteredData();
 354                         if ( $data ) {
 355                                 $data['MEDIAWIKI_EXIF_VERSION'] = Exif::version();
 356                                 return serialize( $data );
 357                         } else {
 358                                 return '0';
 359                         }
 360                 } else {
 361                         return '';
 362                 }
 363         }
 364
 365         function getMetadataType( $image ) {
 366                 return 'exif';
 367         }
 368
 369         function isMetadataValid( $image, $metadata ) {
 370                 global $wgShowEXIF;
 371                 if ( !$wgShowEXIF ) {
 372                         # Metadata disabled and so an empty field is expected
 373                         return true;
 374                 }
 375                 if ( $metadata === '0' ) {
 376                         # Special value indicating that there is no EXIF data in the file
 377                         return true;
 378                 }
 379                 wfSuppressWarnings();
 380                 $exif = unserialize( $metadata );
 381                 wfRestoreWarnings();
 382                 if ( !isset( $exif['MEDIAWIKI_EXIF_VERSION'] ) ||
 383                         $exif['MEDIAWIKI_EXIF_VERSION'] != Exif::version() )
 384                 {
 385                         # Wrong version
 386                         wfDebug( __METHOD__.": wrong version\n" );
 387                         return false;
 388                 }
 389                 return true;
 390         }
 391
 392         /**
 393          * Get a list of EXIF metadata items which should be displayed when
 394          * the metadata table is collapsed.
 395          *
 396          * @return array of strings
 397          * @access private
 398          */
 399         function visibleMetadataFields() {
 400                 $fields = array();
 401                 $lines = explode( "\n", wfMsgForContent( 'metadata-fields' ) );
 402                 foreach( $lines as $line ) {
 403                         $matches = array();
 404                         if( preg_match( '/^\\*\s*(.*?)\s*$/', $line, $matches ) ) {
 405                                 $fields[] = $matches[1];
 406                         }
 407                 }
 408                 $fields = array_map( 'strtolower', $fields );
 409                 return $fields;
 410         }
 411
 412         function formatMetadata( $image ) {
 413                 $result = array(
 414                         'visible' => array(),
 415                         'collapsed' => array()
 416                 );
 417                 $metadata = $image->getMetadata();
 418                 if ( !$metadata ) {
 419                         return false;
 420                 }
 421                 $exif = unserialize( $metadata );
 422                 if ( !$exif ) {
 423                         return false;
 424                 }
 425                 unset( $exif['MEDIAWIKI_EXIF_VERSION'] );
 426                 $format = new FormatExif( $exif );
 427
 428                 $formatted = $format->getFormattedData();
 429                 // Sort fields into visible and collapsed
 430                 $visibleFields = $this->visibleMetadataFields();
 431                 foreach ( $formatted as $name => $value ) {
 432                         $tag = strtolower( $name );
 433                         self::addMeta( $result,
 434                                 in_array( $tag, $visibleFields ) ? 'visible' : 'collapsed',
 435                                 'exif',
 436                                 $tag,
 437                                 $value
 438                         );
 439                 }
 440                 return $result;
 441         }
 442 }