Add a new PNG parser in order to recognize APNG (animated PNG) images.

includes/AutoLoader.php

@@ -444,6 +444,8 @@ $wgAutoloadLocalClasses = array(
 	'MediaHandler' => 'includes/media/Generic.php',
 	'MediaTransformError' => 'includes/media/MediaTransformOutput.php',
 	'MediaTransformOutput' => 'includes/media/MediaTransformOutput.php',
+	'PNGHandler' => 'includes/media/PNG.php',
+	'PNGMetadataExtractor' => 'includes/media/PNGMetadataExtractor.php',
 	'SvgHandler' => 'includes/media/SVG.php',
 	'ThumbnailImage' => 'includes/media/MediaTransformOutput.php',
 	'TiffHandler' => 'includes/media/Tiff.php',

includes/DefaultSettings.php

@@ -562,7 +562,7 @@ $wgTrustedMediaFormats = array(
  */
 $wgMediaHandlers = array(
 	'image/jpeg' => 'BitmapHandler',
-	'image/png' => 'BitmapHandler',
+	'image/png' => 'PNGHandler',
 	'image/gif' => 'GIFHandler',
 	'image/tiff' => 'TiffHandler',
 	'image/x-ms-bmp' => 'BmpHandler',

includes/media/PNG.php

@@ -0,0 +1,82 @@
+<?php
+/**
+ * @file
+ * @ingroup Media
+ */
+
+/**
+ * Handler for PNG images.
+ *
+ * @ingroup Media
+ */
+class PNGHandler extends BitmapHandler {
+	
+	function getMetadata( $image, $filename ) {
+		if ( !isset($image->parsedPNGMetadata) ) {
+			try {
+				$image->parsedPNGMetadata = PNGMetadataExtractor::getMetadata( $filename );
+			} catch( Exception $e ) {
+				// Broken file?
+				wfDebug( __METHOD__ . ': ' . $e->getMessage() . "\n" );
+				return '0';
+			}
+		}
+
+		return serialize($image->parsedPNGMetadata);
+
+	}
+	
+	function formatMetadata( $image ) {
+		return false;
+	}
+	
+	function isAnimatedImage( $image ) {
+		$ser = $image->getMetadata();
+		if ($ser) {
+			$metadata = unserialize($ser);
+			if( $metadata['frameCount'] > 1 ) return true;
+		}
+		return false;
+	}
+	
+	function getMetadataType( $image ) {
+		return 'parsed-png';
+	}
+	
+	function isMetadataValid( $image, $metadata ) {
+		wfSuppressWarnings();
+		$data = unserialize( $metadata );
+		wfRestoreWarnings();
+		return (boolean) $data;
+	}
+	function getLongDesc( $image ) {
+		global $wgUser, $wgLang;
+		$sk = $wgUser->getSkin();
+		$original = parent::getLongDesc( $image );
+
+		wfSuppressWarnings();
+		$metadata = unserialize($image->getMetadata());
+		wfRestoreWarnings();
+
+		if( !metadata || $metadata['frameCount'] == 0 )
+			return $original;
+
+		$info[] = substr( $original, 1, strlen( $original )-2 );
+		
+		if ($metadata['loopCount'] == 0)
+			$info[] = wfMsgExt( 'file-info-png-looped', 'parseinline' );
+		elseif ($metadata['loopCount'] > 1)
+			$info[] = wfMsgExt( 'file-info-png-repeat', 'parseinline', $metadata['loopCount'] );;
+		
+		if ($metadata['frameCount'] > 0)
+			$info[] = wfMsgExt( 'file-info-png-frames', 'parseinline', $metadata['frameCount'] );
+		
+		if ($metadata['duration'])
+			$info[] = $wgLang->formatTimePeriod( $metadata['duration'] );
+		
+		$infoString = $wgLang->commaList( $info );
+		
+		return "($infoString)";
+	}
+
+}

includes/media/PNGMetadataExtractor.php

@@ -0,0 +1,87 @@
+<?php
+/**
+  * PNG frame counter.
+  * Based on 
+  * Deliberately not using MWExceptions to avoid external dependencies, encouraging
+  * redistribution.
+  */
+
+class PNGMetadataExtractor {
+	static $png_sig;
+	static $CRC_size;
+
+	static function getMetadata( $filename ) {
+		self::$png_sig = pack( "C8", 137, 80, 78, 71, 13, 10, 26, 10 );
+		self::$CRC_size = 4;
+		
+		$frameCount = 0;
+		$loopCount = 1;
+		$duration = 0.0;
+
+		if (!$filename)
+			throw new Exception( __METHOD__ . "No file name specified" );
+		elseif ( !file_exists($filename) || is_dir($filename) )
+			throw new Exception( __METHOD__ . "File $filename does not exist" );
+		
+		$fh = fopen( $filename, 'r' );
+		
+		if (!$fh)
+			throw new Exception( __METHOD__ . "Unable to open file $filename" );
+		
+		// Check for the PNG header
+		$buf = fread( $fh, 8 );
+		if ( !($buf == self::$png_sig) ) {
+			throw new Exception( __METHOD__ . "Not a valid PNG file; header: $buf" );
+		}
+
+		// Read chunks
+		while( !feof( $fh ) ) {
+			$buf = fread( $fh, 4 );
+			if( !$buf ) { throw new Exception( __METHOD__ . "Read error" ); return; }
+			$chunk_size = unpack( "N", $buf);
+			$chunk_size = $chunk_size[1];
+
+			$chunk_type = fread( $fh, 4 );
+			if( !$chunk_type ) { throw new Exception( __METHOD__ . "Read error" ); return; }
+
+			if ( $chunk_type == "acTL" ) {
+				$buf = fread( $fh, $chunk_size );
+				if( !$buf ) { throw new Exception( __METHOD__ . "Read error" ); return; }
+
+				$actl = unpack( "Nframes/Nplays", $buf );
+				$frameCount = $actl['frames'];
+				$loopCount = $actl['plays'];
+			} elseif ( $chunk_type == "fcTL" ) {
+				$buf = fread( $fh, $chunk_size );
+				if( !$buf ) { throw new Exception( __METHOD__ . "Read error" ); return; }
+				$buf = substr( $buf, 20 );	
+
+				$fctldur = unpack( "ndelay_num/ndelay_den", $buf );
+				if( $fctldur['delay_den'] == 0 ) $fctldur['delay_den'] = 100;
+				if( $fctldur['delay_num'] ) {
+					$duration += $fctldur['delay_num'] / $fctldur['delay_den'];
+				}
+			} elseif ( ( $chunk_type == "IDAT" || $chunk_type == "IEND" ) && $frameCount == 0 ) {
+				// Not a valid animated image. No point in continuing.
+				break;
+			} elseif ( $chunk_type == "IEND" ) {
+				break;
+			} else {
+				fseek( $fh, $chunk_size, SEEK_CUR );
+			}
+			fseek( $fh, self::$CRC_size, SEEK_CUR );
+		}
+		fclose( $fh );
+
+		if( $loopCount > 1 ) {
+			$duration *= $loopCount;
+		}
+
+		return array(
+			'frameCount' => $frameCount,
+			'loopCount' => $loopCount,
+			'duration' => $duration
+		);
+		
+	}
+}

includes/mime.types

@@ -78,7 +78,7 @@ image/cgm cgm
 image/gif gif
 image/ief ief
 image/jpeg jpeg jpg jpe
-image/png png
+image/png png apng
 image/svg+xml svg
 image/tiff tiff tif
 image/vnd.djvu djvu djv

languages/messages/MessagesEn.php

@@ -3552,6 +3552,9 @@ By executing it, your system may be compromised.<hr />",
 'show-big-image-thumb' => '<small>Size of this preview: $1 × $2 pixels</small>',
 'file-info-gif-looped' => 'looped',
 'file-info-gif-frames' => '$1 {{PLURAL:$1|frame|frames}}',
+'file-info-png-looped' => 'looped',
+'file-info-png-repeat' => 'played $1 times',
+'file-info-png-frames' => '$1 {{PLURAL:$1|frame|frames}}',
 
 # Special:NewFiles
 'newimages'             => 'Gallery of new files',

languages/messages/MessagesQqq.php

@@ -2933,6 +2933,9 @@ The message appears after the name of the patroller.',
 'show-big-image-thumb' => 'File info displayed on file description page.',
 'file-info-gif-looped' => 'Part of the information provided about a [http://en.wikipedia.org/wiki/Gif .gif file] on its file description page. Looped means repeating in the context of an animated gif. It is a sequence of images, each displayed after the other, and the first one displayed after the last, in a never ending loop. For example of message in use see [[:File:Mouse10.gif]].',
 'file-info-gif-frames' => 'Part of the information provided about a [http://en.wikipedia.org/wiki/Gif .gif file] on its file description page.
+'file-info-png-looped' => 'Part of the information provided about a [http://en.wikipedia.org/wiki/APNG .apng file] on its file description page. Looped means repeating indefinetly in the context of an animated png. It is a sequence of images, each displayed after the other, and the first one displayed after the last, in a never ending loop.',
+'file-info-png-repeat' => 'Part of the information provided about a [http://en.wikipedia.org/wiki/APNG .apng file] on its file description page. The sequence of images is repeating a limited amount of time. It is a sequence of images, each displayed after the other, and the first one displayed after the last, for $1 times.',
+'file-info-png-frames' => 'Part of the information provided about a [http://en.wikipedia.org/wiki/APNG .apng file] on its file description page.
 
 The variable $1 is the number of individual frames in an animated gif file.
 

maintenance/language/messages.inc

@@ -2510,6 +2510,9 @@ $wgMessageStructure = array(
 		'show-big-image-thumb',
 		'file-info-gif-looped',
 		'file-info-gif-frames',
+		'file-info-png-looped',
+		'file-info-png-repeat',
+		'file-info-png-frames',
 	),
 	'newfiles' => array(
 		'newimages',