1 files changed, 269 insertions, 0 deletions
diff --git a/includes/media/BitmapMetadataHandler.php b/includes/media/BitmapMetadataHandler.php
new file mode 100644
index 00000000..d1caa67a
--- /dev/null
+++ b/includes/media/BitmapMetadataHandler.php
@@ -0,0 +1,269 @@
+<?php
+/**
+Class to deal with reconciling and extracting metadata from bitmap images.
+This is meant to comply with http://www.metadataworkinggroup.org/pdf/mwg_guidance.pdf
+
+This sort of acts as an intermediary between MediaHandler::getMetadata
+and the various metadata extractors.
+
+@todo other image formats.
+*/
+class BitmapMetadataHandler {
+
+	private $metadata = array();
+	private $metaPriority = array(
+		20 => array( 'other' ),
+		40 => array( 'native' ),
+		60 => array( 'iptc-good-hash', 'iptc-no-hash' ),
+		70 => array( 'xmp-deprecated' ),
+		80 => array( 'xmp-general' ),
+		90 => array( 'xmp-exif' ),
+		100 => array( 'iptc-bad-hash' ),
+		120 => array( 'exif' ),
+	);
+	private $iptcType = 'iptc-no-hash';
+
+	/**
+	* This does the photoshop image resource app13 block
+	* of interest, IPTC-IIM metadata is stored here.
+	*
+	* Mostly just calls doPSIR and doIPTC
+	*
+	* @param String $app13 String containing app13 block from jpeg file
+	*/
+	private function doApp13 ( $app13 ) {
+		$this->iptcType = JpegMetadataExtractor::doPSIR( $app13 );
+
+		$iptc = IPTC::parse( $app13 );
+		$this->addMetadata( $iptc, $this->iptcType );
+	}
+
+
+	/**
+	 * Get exif info using exif class.
+	 * Basically what used to be in BitmapHandler::getMetadata().
+	 * Just calls stuff in the Exif class.
+	 *
+	 * @param $filename string
+	 */
+	function getExif ( $filename, $byteOrder ) {
+		global $wgShowEXIF;
+		if ( file_exists( $filename ) && $wgShowEXIF ) {
+			$exif = new Exif( $filename, $byteOrder );
+			$data = $exif->getFilteredData();
+			if ( $data ) {
+				$this->addMetadata( $data, 'exif' );
+			}
+		}
+	}
+	/** Add misc metadata. Warning: atm if the metadata category
+	* doesn't have a priority, it will be silently discarded.
+	*
+	* @param Array $metaArray array of metadata values
+	* @param string $type type. defaults to other. if two things have the same type they're merged
+	*/
+	function addMetadata ( $metaArray, $type = 'other' ) {
+		if ( isset( $this->metadata[$type] ) ) {
+			/* merge with old data */
+			$metaArray = $metaArray + $this->metadata[$type];
+		}
+
+		$this->metadata[$type] = $metaArray;
+	}
+
+	/**
+	* Merge together the various types of metadata
+	* the different types have different priorites,
+	* and are merged in order.
+	*
+	* This function is generally called by the media handlers' getMetadata()
+	*
+	* @return Array metadata array
+	*/
+	function getMetadataArray () {
+		// this seems a bit ugly... This is all so its merged in right order
+		// based on the MWG recomendation.
+		$temp = Array();
+		krsort( $this->metaPriority );
+		foreach ( $this->metaPriority as $pri ) {
+			foreach ( $pri as $type ) {
+				if ( isset( $this->metadata[$type] ) ) {
+					// Do some special casing for multilingual values.
+					// Don't discard translations if also as a simple value.
+					foreach ( $this->metadata[$type] as $itemName => $item ) {
+						if ( is_array( $item ) && isset( $item['_type'] ) && $item['_type'] === 'lang' ) {
+							if ( isset( $temp[$itemName] ) && !is_array( $temp[$itemName] ) ) {
+								$default = $temp[$itemName];
+								$temp[$itemName] = $item;
+								$temp[$itemName]['x-default'] = $default;
+								unset( $this->metadata[$type][$itemName] );
+							}
+						}
+					}
+
+					$temp = $temp + $this->metadata[$type];
+				}
+			}
+		}
+		return $temp;
+	}
+
+	/** Main entry point for jpeg's.
+	 *
+	 * @param $filename string filename (with full path)
+	 * @return metadata result array.
+	 * @throws MWException on invalid file.
+	 */
+	static function Jpeg ( $filename ) {
+		$showXMP = function_exists( 'xml_parser_create_ns' );
+		$meta = new self();
+
+		$seg = JpegMetadataExtractor::segmentSplitter( $filename );
+		if ( isset( $seg['COM'] ) && isset( $seg['COM'][0] ) ) {
+			$meta->addMetadata( Array( 'JPEGFileComment' => $seg['COM'] ), 'native' );
+		}
+		if ( isset( $seg['PSIR'] ) ) {
+			$meta->doApp13( $seg['PSIR'] );
+		}
+		if ( isset( $seg['XMP'] ) && $showXMP ) {
+			$xmp = new XMPReader();
+			$xmp->parse( $seg['XMP'] );
+			foreach ( $seg['XMP_ext'] as $xmpExt ) {
+				/* Support for extended xmp in jpeg files
+				 * is not well tested and a bit fragile.
+				 */
+				$xmp->parseExtended( $xmpExt );
+
+			}
+			$res = $xmp->getResults();
+			foreach ( $res as $type => $array ) {
+				$meta->addMetadata( $array, $type );
+			}
+		}
+		if ( isset( $seg['byteOrder'] ) ) {
+			$meta->getExif( $filename, $seg['byteOrder'] );
+		}
+		return $meta->getMetadataArray();
+	}
+
+	/** Entry point for png
+	 * At some point in the future this might
+	 * merge the png various tEXt chunks to that
+	 * are interesting, but for now it only does XMP
+	 *
+	 * @param $filename String full path to file
+	 * @return Array Array for storage in img_metadata.
+	 */
+	static public function PNG ( $filename ) {
+		$showXMP = function_exists( 'xml_parser_create_ns' );
+
+		$meta = new self();
+		$array = PNGMetadataExtractor::getMetadata( $filename );
+		if ( isset( $array['text']['xmp']['x-default'] ) && $array['text']['xmp']['x-default'] !== '' && $showXMP ) {
+			$xmp = new XMPReader();
+			$xmp->parse( $array['text']['xmp']['x-default'] );
+			$xmpRes = $xmp->getResults();
+			foreach ( $xmpRes as $type => $xmpSection ) {
+				$meta->addMetadata( $xmpSection, $type );
+			}
+		}
+		unset( $array['text']['xmp'] );
+		$meta->addMetadata( $array['text'], 'native' );
+		unset( $array['text'] );
+		$array['metadata'] = $meta->getMetadataArray();
+		$array['metadata']['_MW_PNG_VERSION'] = PNGMetadataExtractor::VERSION;
+		return $array;
+	}
+
+	/** function for gif images.
+	 *
+	 * They don't really have native metadata, so just merges together
+	 * XMP and image comment.
+	 *
+	 * @param $filename full path to file
+	 * @return Array metadata array
+	 */
+	static public function GIF ( $filename ) {
+
+		$meta = new self();
+		$baseArray = GIFMetadataExtractor::getMetadata( $filename );
+
+		if ( count( $baseArray['comment'] ) > 0 ) {
+			$meta->addMetadata( array( 'GIFFileComment' => $baseArray['comment'] ), 'native' );
+		}
+
+		if ( $baseArray['xmp'] !== '' && function_exists( 'xml_parser_create_ns' ) ) {
+			$xmp = new XMPReader();
+			$xmp->parse( $baseArray['xmp'] );
+			$xmpRes = $xmp->getResults();
+			foreach ( $xmpRes as $type => $xmpSection ) {
+				$meta->addMetadata( $xmpSection, $type );
+			}
+
+		}
+
+		unset( $baseArray['comment'] );
+		unset( $baseArray['xmp'] );
+	
+		$baseArray['metadata'] = $meta->getMetadataArray();
+		$baseArray['metadata']['_MW_GIF_VERSION'] = GIFMetadataExtractor::VERSION;
+		return $baseArray;
+	}
+
+	/**
+	 * This doesn't do much yet, but eventually I plan to add
+	 * XMP support for Tiff. (PHP's exif support already extracts
+	 * but needs some further processing because PHP's exif support
+	 * is stupid...)
+	 *
+	 * @todo Add XMP support, so this function actually makes
+	 * sense to put here.
+	 *
+	 * The various exceptions this throws are caught later.
+	 * @param $filename String
+	 * @return Array The metadata.
+	 */
+	static public function Tiff ( $filename ) {
+		if ( file_exists( $filename ) ) {
+			$byteOrder = self::getTiffByteOrder( $filename );
+			if ( !$byteOrder ) {
+				throw new MWException( "Error determining byte order of $filename" );
+			}
+			$exif = new Exif( $filename, $byteOrder );
+			$data = $exif->getFilteredData();
+			if ( $data ) {
+				$data['MEDIAWIKI_EXIF_VERSION'] = Exif::version();
+				return $data;
+			} else {
+				throw new MWException( "Could not extract data from tiff file $filename" );
+			}
+		} else {
+			throw new MWException( "File doesn't exist - $filename" );
+		}
+	}
+	/**
+	 * Read the first 2 bytes of a tiff file to figure out
+	 * Little Endian or Big Endian. Needed for exif stuff.
+	 *
+	 * @param $filename String The filename
+	 * @return String 'BE' or 'LE' or false
+	 */
+	static function getTiffByteOrder( $filename ) {
+		$fh = fopen( $filename, 'rb' );
+		if ( !$fh ) return false;
+		$head = fread( $fh, 2 );
+		fclose( $fh );
+
+		switch( $head ) {
+			case 'II':
+				return 'LE'; // II for intel.
+			case 'MM':
+				return 'BE'; // MM for motorla.
+			default:
+				return false; // Something went wrong.
+
+		}
+	}
+
+
+}