includes/media/GIF.php

   1 <?php
   2 /**
   3  * Handler for GIF 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  * Handler for GIF images.
  26  *
  27  * @ingroup Media
  28  */
  29 class GIFHandler extends BitmapHandler {
  30         const BROKEN_FILE = '0'; // value to store in img_metadata if error extracting metadata.
  31
  32         function getMetadata( $image, $filename ) {
  33                 try {
  34                         $parsedGIFMetadata = BitmapMetadataHandler::GIF( $filename );
  35                 } catch ( Exception $e ) {
  36                         // Broken file?
  37                         wfDebug( __METHOD__ . ': ' . $e->getMessage() . "\n" );
  38
  39                         return self::BROKEN_FILE;
  40                 }
  41
  42                 return serialize( $parsedGIFMetadata );
  43         }
  44
  45         /**
  46          * @param File $image
  47          * @param bool|IContextSource $context Context to use (optional)
  48          * @return array|bool
  49          */
  50         function formatMetadata( $image, $context = false ) {
  51                 $meta = $this->getCommonMetaArray( $image );
  52                 if ( count( $meta ) === 0 ) {
  53                         return false;
  54                 }
  55
  56                 return $this->formatMetadataHelper( $meta, $context );
  57         }
  58
  59         /**
  60          * Return the standard metadata elements for #filemetadata parser func.
  61          * @param File $image
  62          * @return array|bool
  63          */
  64         public function getCommonMetaArray( File $image ) {
  65                 $meta = $image->getMetadata();
  66
  67                 if ( !$meta ) {
  68                         return array();
  69                 }
  70                 $meta = unserialize( $meta );
  71                 if ( !isset( $meta['metadata'] ) ) {
  72                         return array();
  73                 }
  74                 unset( $meta['metadata']['_MW_GIF_VERSION'] );
  75
  76                 return $meta['metadata'];
  77         }
  78
  79         /**
  80          * @todo Add unit tests
  81          *
  82          * @param File $image
  83          * @return bool
  84          */
  85         function getImageArea( $image ) {
  86                 $ser = $image->getMetadata();
  87                 if ( $ser ) {
  88                         $metadata = unserialize( $ser );
  89
  90                         return $image->getWidth() * $image->getHeight() * $metadata['frameCount'];
  91                 } else {
  92                         return $image->getWidth() * $image->getHeight();
  93                 }
  94         }
  95
  96         /**
  97          * @param File $image
  98          * @return bool
  99          */
 100         function isAnimatedImage( $image ) {
 101                 $ser = $image->getMetadata();
 102                 if ( $ser ) {
 103                         $metadata = unserialize( $ser );
 104                         if ( $metadata['frameCount'] > 1 ) {
 105                                 return true;
 106                         }
 107                 }
 108
 109                 return false;
 110         }
 111
 112         /**
 113          * We cannot animate thumbnails that are bigger than a particular size
 114          * @param File $file
 115          * @return bool
 116          */
 117         function canAnimateThumbnail( $file ) {
 118                 global $wgMaxAnimatedGifArea;
 119                 $answer = $this->getImageArea( $file ) <= $wgMaxAnimatedGifArea;
 120
 121                 return $answer;
 122         }
 123
 124         function getMetadataType( $image ) {
 125                 return 'parsed-gif';
 126         }
 127
 128         function isMetadataValid( $image, $metadata ) {
 129                 if ( $metadata === self::BROKEN_FILE ) {
 130                         // Do not repetitivly regenerate metadata on broken file.
 131                         return self::METADATA_GOOD;
 132                 }
 133
 134                 wfSuppressWarnings();
 135                 $data = unserialize( $metadata );
 136                 wfRestoreWarnings();
 137
 138                 if ( !$data || !is_array( $data ) ) {
 139                         wfDebug( __METHOD__ . " invalid GIF metadata\n" );
 140
 141                         return self::METADATA_BAD;
 142                 }
 143
 144                 if ( !isset( $data['metadata']['_MW_GIF_VERSION'] )
 145                         || $data['metadata']['_MW_GIF_VERSION'] != GIFMetadataExtractor::VERSION
 146                 ) {
 147                         wfDebug( __METHOD__ . " old but compatible GIF metadata\n" );
 148
 149                         return self::METADATA_COMPATIBLE;
 150                 }
 151
 152                 return self::METADATA_GOOD;
 153         }
 154
 155         /**
 156          * @param File $image
 157          * @return string
 158          */
 159         function getLongDesc( $image ) {
 160                 global $wgLang;
 161
 162                 $original = parent::getLongDesc( $image );
 163
 164                 wfSuppressWarnings();
 165                 $metadata = unserialize( $image->getMetadata() );
 166                 wfRestoreWarnings();
 167
 168                 if ( !$metadata || $metadata['frameCount'] <= 1 ) {
 169                         return $original;
 170                 }
 171
 172                 /* Preserve original image info string, but strip the last char ')' so we can add even more */
 173                 $info = array();
 174                 $info[] = $original;
 175
 176                 if ( $metadata['looped'] ) {
 177                         $info[] = wfMessage( 'file-info-gif-looped' )->parse();
 178                 }
 179
 180                 if ( $metadata['frameCount'] > 1 ) {
 181                         $info[] = wfMessage( 'file-info-gif-frames' )->numParams( $metadata['frameCount'] )->parse();
 182                 }
 183
 184                 if ( $metadata['duration'] ) {
 185                         $info[] = $wgLang->formatTimePeriod( $metadata['duration'] );
 186                 }
 187
 188                 return $wgLang->commaList( $info );
 189         }
 190 }