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