includes/media/ExifBitmap.php

   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  32         const OLD_BROKEN_FILE = '0'; // outdated error extracting metadata.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         function isMetadataValid( $image, $metadata ) {
  83                 global $wgShowEXIF;
  84                 if ( !$wgShowEXIF ) {
  85                         # Metadata disabled and so an empty field is expected
  86                         return self::METADATA_GOOD;
  87                 }
  88                 if ( $metadata === self::OLD_BROKEN_FILE ) {
  89                         # Old special value indicating that there is no Exif data in the file.
  90                         # or that there was an error well extracting the metadata.
  91                         wfDebug( __METHOD__ . ": back-compat version\n" );
  92
  93                         return self::METADATA_COMPATIBLE;
  94                 }
  95                 if ( $metadata === self::BROKEN_FILE ) {
  96                         return self::METADATA_GOOD;
  97                 }
  98                 wfSuppressWarnings();
  99                 $exif = unserialize( $metadata );
 100                 wfRestoreWarnings();
 101                 if ( !isset( $exif['MEDIAWIKI_EXIF_VERSION'] )
 102                         || $exif['MEDIAWIKI_EXIF_VERSION'] != Exif::version()
 103                 ) {
 104                         if ( isset( $exif['MEDIAWIKI_EXIF_VERSION'] )
 105                                 && $exif['MEDIAWIKI_EXIF_VERSION'] == 1
 106                         ) {
 107                                 //back-compatible but old
 108                                 wfDebug( __METHOD__ . ": back-compat version\n" );
 109
 110                                 return self::METADATA_COMPATIBLE;
 111                         }
 112                         # Wrong (non-compatible) version
 113                         wfDebug( __METHOD__ . ": wrong version\n" );
 114
 115                         return self::METADATA_BAD;
 116                 }
 117
 118                 return self::METADATA_GOOD;
 119         }
 120
 121         /**
 122          * @param $image File
 123          * @return array|bool
 124          */
 125         function formatMetadata( $image ) {
 126                 $meta = $this->getCommonMetaArray( $image );
 127                 if ( count( $meta ) === 0 ) {
 128                         return false;
 129                 }
 130
 131                 return $this->formatMetadataHelper( $meta );
 132         }
 133
 134         public function getCommonMetaArray( File $file ) {
 135                 $metadata = $file->getMetadata();
 136                 if ( $metadata === self::OLD_BROKEN_FILE
 137                         || $metadata === self::BROKEN_FILE
 138                         || $this->isMetadataValid( $file, $metadata ) === self::METADATA_BAD
 139                 ) {
 140                         // So we don't try and display metadata from PagedTiffHandler
 141                         // for example when using InstantCommons.
 142                         return array();
 143                 }
 144
 145                 $exif = unserialize( $metadata );
 146                 if ( !$exif ) {
 147                         return array();
 148                 }
 149                 unset( $exif['MEDIAWIKI_EXIF_VERSION'] );
 150
 151                 return $exif;
 152         }
 153
 154         function getMetadataType( $image ) {
 155                 return 'exif';
 156         }
 157
 158         /**
 159          * Wrapper for base classes ImageHandler::getImageSize() that checks for
 160          * rotation reported from metadata and swaps the sizes to match.
 161          *
 162          * @param File $image
 163          * @param string $path
 164          * @return array
 165          */
 166         function getImageSize( $image, $path ) {
 167                 global $wgEnableAutoRotation;
 168                 $gis = parent::getImageSize( $image, $path );
 169
 170                 // Don't just call $image->getMetadata(); FSFile::getPropsFromPath() calls us with a bogus object.
 171                 // This may mean we read EXIF data twice on initial upload.
 172                 if ( $wgEnableAutoRotation ) {
 173                         $meta = $this->getMetadata( $image, $path );
 174                         $rotation = $this->getRotationForExif( $meta );
 175                 } else {
 176                         $rotation = 0;
 177                 }
 178
 179                 if ( $rotation == 90 || $rotation == 270 ) {
 180                         $width = $gis[0];
 181                         $gis[0] = $gis[1];
 182                         $gis[1] = $width;
 183                 }
 184
 185                 return $gis;
 186         }
 187
 188         /**
 189          * On supporting image formats, try to read out the low-level orientation
 190          * of the file and return the angle that the file needs to be rotated to
 191          * be viewed.
 192          *
 193          * This information is only useful when manipulating the original file;
 194          * the width and height we normally work with is logical, and will match
 195          * any produced output views.
 196          *
 197          * @param $file File
 198          * @return int 0, 90, 180 or 270
 199          */
 200         public function getRotation( $file ) {
 201                 global $wgEnableAutoRotation;
 202                 if ( !$wgEnableAutoRotation ) {
 203                         return 0;
 204                 }
 205
 206                 $data = $file->getMetadata();
 207
 208                 return $this->getRotationForExif( $data );
 209         }
 210
 211         /**
 212          * Given a chunk of serialized Exif metadata, return the orientation as
 213          * degrees of rotation.
 214          *
 215          * @param string $data
 216          * @return int 0, 90, 180 or 270
 217          * @todo FIXME orientation can include flipping as well; see if this is an
 218          * issue!
 219          */
 220         protected function getRotationForExif( $data ) {
 221                 if ( !$data ) {
 222                         return 0;
 223                 }
 224                 wfSuppressWarnings();
 225                 $data = unserialize( $data );
 226                 wfRestoreWarnings();
 227                 if ( isset( $data['Orientation'] ) ) {
 228                         # See http://sylvana.net/jpegcrop/exif_orientation.html
 229                         switch ( $data['Orientation'] ) {
 230                                 case 8:
 231                                         return 90;
 232                                 case 3:
 233                                         return 180;
 234                                 case 6:
 235                                         return 270;
 236                                 default:
 237                                         return 0;
 238                         }
 239                 }
 240
 241                 return 0;
 242         }
 243 }