[Summary view] [Print] [Text view]

   1  <?php
   2  /**
   3   * Handler for bitmap images with exif metadata.
   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   * Stuff specific to JPEG and (built-in) TIFF handler.
  26   * All metadata related, since both JPEG and TIFF support Exif.
  27   *
  28   * @ingroup Media
  29   */
  30  class ExifBitmapHandler extends BitmapHandler {
  31      const BROKEN_FILE = '-1'; // error extracting metadata
  32      const OLD_BROKEN_FILE = '0'; // outdated error extracting metadata.
  33  
  34  	function convertMetadataVersion( $metadata, $version = 1 ) {
  35          // basically flattens arrays.
  36          $version = explode( ';', $version, 2 );
  37          $version = intval( $version[0] );
  38          if ( $version < 1 || $version >= 2 ) {
  39              return $metadata;
  40          }
  41  
  42          $avoidHtml = true;
  43  
  44          if ( !is_array( $metadata ) ) {
  45              $metadata = unserialize( $metadata );
  46          }
  47          if ( !isset( $metadata['MEDIAWIKI_EXIF_VERSION'] ) || $metadata['MEDIAWIKI_EXIF_VERSION'] != 2 ) {
  48              return $metadata;
  49          }
  50  
  51          // Treat Software as a special case because in can contain
  52          // an array of (SoftwareName, Version).
  53          if ( isset( $metadata['Software'] )
  54              && is_array( $metadata['Software'] )
  55              && is_array( $metadata['Software'][0] )
  56              && isset( $metadata['Software'][0][0] )
  57              && isset( $metadata['Software'][0][1] )
  58          ) {
  59              $metadata['Software'] = $metadata['Software'][0][0] . ' (Version '
  60                  . $metadata['Software'][0][1] . ')';
  61          }
  62  
  63          $formatter = new FormatMetadata;
  64  
  65          // ContactInfo also has to be dealt with specially
  66          if ( isset( $metadata['Contact'] ) ) {
  67              $metadata['Contact'] =
  68                  $formatter->collapseContactInfo(
  69                      $metadata['Contact'] );
  70          }
  71  
  72          foreach ( $metadata as &$val ) {
  73              if ( is_array( $val ) ) {
  74                  $val = $formatter->flattenArrayReal( $val, 'ul', $avoidHtml );
  75              }
  76          }
  77          $metadata['MEDIAWIKI_EXIF_VERSION'] = 1;
  78  
  79          return $metadata;
  80      }
  81  
  82      /**
  83       * @param File $image
  84       * @param array $metadata
  85       * @return bool|int
  86       */
  87  	function isMetadataValid( $image, $metadata ) {
  88          global $wgShowEXIF;
  89          if ( !$wgShowEXIF ) {
  90              # Metadata disabled and so an empty field is expected
  91              return self::METADATA_GOOD;
  92          }
  93          if ( $metadata === self::OLD_BROKEN_FILE ) {
  94              # Old special value indicating that there is no Exif data in the file.
  95              # or that there was an error well extracting the metadata.
  96              wfDebug( __METHOD__ . ": back-compat version\n" );
  97  
  98              return self::METADATA_COMPATIBLE;
  99          }
 100          if ( $metadata === self::BROKEN_FILE ) {
 101              return self::METADATA_GOOD;
 102          }
 103          wfSuppressWarnings();
 104          $exif = unserialize( $metadata );
 105          wfRestoreWarnings();
 106          if ( !isset( $exif['MEDIAWIKI_EXIF_VERSION'] )
 107              || $exif['MEDIAWIKI_EXIF_VERSION'] != Exif::version()
 108          ) {
 109              if ( isset( $exif['MEDIAWIKI_EXIF_VERSION'] )
 110                  && $exif['MEDIAWIKI_EXIF_VERSION'] == 1
 111              ) {
 112                  //back-compatible but old
 113                  wfDebug( __METHOD__ . ": back-compat version\n" );
 114  
 115                  return self::METADATA_COMPATIBLE;
 116              }
 117              # Wrong (non-compatible) version
 118              wfDebug( __METHOD__ . ": wrong version\n" );
 119  
 120              return self::METADATA_BAD;
 121          }
 122  
 123          return self::METADATA_GOOD;
 124      }
 125  
 126      /**
 127       * @param File $image
 128       * @return array|bool
 129       */
 130  	function formatMetadata( $image ) {
 131          $meta = $this->getCommonMetaArray( $image );
 132          if ( count( $meta ) === 0 ) {
 133              return false;
 134          }
 135  
 136          return $this->formatMetadataHelper( $meta );
 137      }
 138  
 139  	public function getCommonMetaArray( File $file ) {
 140          $metadata = $file->getMetadata();
 141          if ( $metadata === self::OLD_BROKEN_FILE
 142              || $metadata === self::BROKEN_FILE
 143              || $this->isMetadataValid( $file, $metadata ) === self::METADATA_BAD
 144          ) {
 145              // So we don't try and display metadata from PagedTiffHandler
 146              // for example when using InstantCommons.
 147              return array();
 148          }
 149  
 150          $exif = unserialize( $metadata );
 151          if ( !$exif ) {
 152              return array();
 153          }
 154          unset( $exif['MEDIAWIKI_EXIF_VERSION'] );
 155  
 156          return $exif;
 157      }
 158  
 159  	function getMetadataType( $image ) {
 160          return 'exif';
 161      }
 162  
 163      /**
 164       * Wrapper for base classes ImageHandler::getImageSize() that checks for
 165       * rotation reported from metadata and swaps the sizes to match.
 166       *
 167       * @param File $image
 168       * @param string $path
 169       * @return array
 170       */
 171  	function getImageSize( $image, $path ) {
 172          $gis = parent::getImageSize( $image, $path );
 173  
 174          // Don't just call $image->getMetadata(); FSFile::getPropsFromPath() calls us with a bogus object.
 175          // This may mean we read EXIF data twice on initial upload.
 176          if ( $this->autoRotateEnabled() ) {
 177              $meta = $this->getMetadata( $image, $path );
 178              $rotation = $this->getRotationForExif( $meta );
 179          } else {
 180              $rotation = 0;
 181          }
 182  
 183          if ( $rotation == 90 || $rotation == 270 ) {
 184              $width = $gis[0];
 185              $gis[0] = $gis[1];
 186              $gis[1] = $width;
 187          }
 188  
 189          return $gis;
 190      }
 191  
 192      /**
 193       * On supporting image formats, try to read out the low-level orientation
 194       * of the file and return the angle that the file needs to be rotated to
 195       * be viewed.
 196       *
 197       * This information is only useful when manipulating the original file;
 198       * the width and height we normally work with is logical, and will match
 199       * any produced output views.
 200       *
 201       * @param File $file
 202       * @return int 0, 90, 180 or 270
 203       */
 204  	public function getRotation( $file ) {
 205          if ( !$this->autoRotateEnabled() ) {
 206              return 0;
 207          }
 208  
 209          $data = $file->getMetadata();
 210  
 211          return $this->getRotationForExif( $data );
 212      }
 213  
 214      /**
 215       * Given a chunk of serialized Exif metadata, return the orientation as
 216       * degrees of rotation.
 217       *
 218       * @param string $data
 219       * @return int 0, 90, 180 or 270
 220       * @todo FIXME: Orientation can include flipping as well; see if this is an issue!
 221       */
 222  	protected function getRotationForExif( $data ) {
 223          if ( !$data ) {
 224              return 0;
 225          }
 226          wfSuppressWarnings();
 227          $data = unserialize( $data );
 228          wfRestoreWarnings();
 229          if ( isset( $data['Orientation'] ) ) {
 230              # See http://sylvana.net/jpegcrop/exif_orientation.html
 231              switch ( $data['Orientation'] ) {
 232                  case 8:
 233                      return 90;
 234                  case 3:
 235                      return 180;
 236                  case 6:
 237                      return 270;
 238                  default:
 239                      return 0;
 240              }
 241          }
 242  
 243          return 0;
 244      }
 245  }