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