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