1 files changed, 306 insertions, 0 deletions
diff --git a/includes/media/WebP.php b/includes/media/WebP.php
new file mode 100644
index 00000000..ff4dcee2
--- /dev/null
+++ b/includes/media/WebP.php
@@ -0,0 +1,306 @@
+<?php
+/**
+ * Handler for Google's WebP format <https://developers.google.com/speed/webp/>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Media
+ */
+
+/**
+ * Handler for Google's WebP format <https://developers.google.com/speed/webp/>
+ *
+ * @ingroup Media
+ */
+class WebPHandler extends BitmapHandler {
+	const BROKEN_FILE = '0'; // value to store in img_metadata if error extracting metadata.
+	/**
+	 * @var int Minimum chunk header size to be able to read all header types
+	 */
+	const MINIMUM_CHUNK_HEADER_LENGTH = 18;
+	/**
+	 * @var int version of the metadata stored in db records
+	 */
+	const _MW_WEBP_VERSION = 1;
+
+	const VP8X_ICC = 32;
+	const VP8X_ALPHA = 16;
+	const VP8X_EXIF = 8;
+	const VP8X_XMP = 4;
+	const VP8X_ANIM = 2;
+
+	public function getMetadata( $image, $filename ) {
+		$parsedWebPData = self::extractMetadata( $filename );
+		if ( !$parsedWebPData ) {
+			return self::BROKEN_FILE;
+		}
+
+		$parsedWebPData['metadata']['_MW_WEBP_VERSION'] = self::_MW_WEBP_VERSION;
+		return serialize( $parsedWebPData );
+	}
+
+	public function getMetadataType( $image ) {
+		return 'parsed-webp';
+	}
+
+	public function isMetadataValid( $image, $metadata ) {
+		if ( $metadata === self::BROKEN_FILE ) {
+				// Do not repetitivly regenerate metadata on broken file.
+				return self::METADATA_GOOD;
+		}
+
+		wfSuppressWarnings();
+		$data = unserialize( $metadata );
+		wfRestoreWarnings();
+
+		if ( !$data || !is_array( $data ) ) {
+				wfDebug( __METHOD__ . " invalid WebP metadata\n" );
+
+				return self::METADATA_BAD;
+		}
+
+		if ( !isset( $data['metadata']['_MW_WEBP_VERSION'] )
+				|| $data['metadata']['_MW_WEBP_VERSION'] != self::_MW_WEBP_VERSION
+		) {
+				wfDebug( __METHOD__ . " old but compatible WebP metadata\n" );
+
+				return self::METADATA_COMPATIBLE;
+		}
+		return self::METADATA_GOOD;
+	}
+
+	/**
+	 * Extracts the image size and WebP type from a file
+	 *
+	 * @param string $chunks Chunks as extracted by RiffExtractor
+	 * @return array|bool Header data array with entries 'compression', 'width' and 'height',
+	 * where 'compression' can be 'lossy', 'lossless', 'animated' or 'unknown'. False if
+	 * file is not a valid WebP file.
+	 */
+	public static function extractMetadata( $filename ) {
+		wfDebugLog( 'WebP', __METHOD__ . ": Extracting metadata from $filename\n" );
+
+		$info = RiffExtractor::findChunksFromFile( $filename, 100 );
+		if ( $info === false ) {
+			wfDebugLog( 'WebP', __METHOD__ . ": Not a valid RIFF file\n" );
+			return false;
+		}
+
+		if ( $info['fourCC'] != 'WEBP' ) {
+			wfDebugLog( 'WebP', __METHOD__ . ': FourCC was not WEBP: ' .
+				bin2hex( $info['fourCC'] ) .  " \n" );
+			return false;
+		}
+
+		$metadata = self::extractMetadataFromChunks( $info['chunks'], $filename );
+		if ( !$metadata ) {
+			wfDebugLog( 'WebP', __METHOD__ . ": No VP8 chunks found\n" );
+			return false;
+		}
+
+		return $metadata;
+	}
+
+	/**
+	 * Extracts the image size and WebP type from a file based on the chunk list
+	 * @param array $chunks Chunks as extracted by RiffExtractor
+	 * @return array Header data array with entries 'compression', 'width' and 'height', where
+	 * 'compression' can be 'lossy', 'lossless', 'animated' or 'unknown'
+	 */
+	public static function extractMetadataFromChunks( $chunks, $filename ) {
+		$vp8Info = array();
+
+		foreach ( $chunks as $chunk ) {
+			if ( !in_array( $chunk['fourCC'], array( 'VP8 ', 'VP8L', 'VP8X' ) ) ) {
+				// Not a chunk containing interesting metadata
+				continue;
+			}
+
+			$chunkHeader = file_get_contents( $filename, false, null,
+				$chunk['start'], self::MINIMUM_CHUNK_HEADER_LENGTH );
+			wfDebugLog( 'WebP', __METHOD__ . ": {$chunk['fourCC']}\n" );
+
+			switch ( $chunk['fourCC'] ) {
+				case 'VP8 ':
+					return array_merge( $vp8Info,
+						self::decodeLossyChunkHeader( $chunkHeader ) );
+				case 'VP8L':
+					return array_merge( $vp8Info,
+						self::decodeLosslessChunkHeader( $chunkHeader ) );
+				case 'VP8X':
+					$vp8Info = array_merge( $vp8Info,
+						self::decodeExtendedChunkHeader( $chunkHeader ) );
+					// Continue looking for other chunks to improve the metadata
+					break;
+			}
+		}
+		return $vp8Info;
+	}
+
+	/**
+	 * Decodes a lossy chunk header
+	 * @param string $header Header string
+	 * @return boolean|array See WebPHandler::decodeHeader
+	 */
+	protected static function decodeLossyChunkHeader( $header ) {
+		// Bytes 0-3 are 'VP8 '
+		// Bytes 4-7 are the VP8 stream size
+		// Bytes 8-10 are the frame tag
+		// Bytes 11-13 are 0x9D 0x01 0x2A called the sync code
+		$syncCode = substr( $header, 11, 3 );
+		if ( $syncCode != "\x9D\x01\x2A" ) {
+			wfDebugLog( 'WebP', __METHOD__ . ': Invalid sync code: ' .
+				bin2hex( $syncCode ) . "\n" );
+			return array();
+		}
+		// Bytes 14-17 are image size
+		$imageSize = unpack( 'v2', substr( $header, 14, 4 ) );
+		// Image sizes are 14 bit, 2 MSB are scaling parameters which are ignored here
+		return array(
+			'compression' => 'lossy',
+			'width' => $imageSize[1] & 0x3FFF,
+			'height' => $imageSize[2] & 0x3FFF
+		);
+	}
+
+	/**
+	 * Decodes a lossless chunk header
+	 * @param string $header Header string
+	 * @return boolean|array See WebPHandler::decodeHeader
+	 */
+	public static function decodeLosslessChunkHeader( $header ) {
+		// Bytes 0-3 are 'VP8L'
+		// Bytes 4-7 are chunk stream size
+		// Byte 8 is 0x2F called the signature
+		if ( $header{8} != "\x2F" ) {
+			wfDebugLog( 'WebP',  __METHOD__ . ': Invalid signature: ' .
+				bin2hex( $header{8} ) . "\n" );
+			return array();
+		}
+		// Bytes 9-12 contain the image size
+		// Bits 0-13 are width-1; bits 15-27 are height-1
+		$imageSize = unpack( 'C4', substr( $header, 9, 4 ) );
+		return array(
+				'compression' => 'lossless',
+				'width' => ( $imageSize[1] | ( ( $imageSize[2] & 0x3F ) << 8 ) ) + 1,
+				'height' => ( ( ( $imageSize[2] & 0xC0 ) >> 6 ) |
+						( $imageSize[3] << 2 ) | ( ( $imageSize[4] & 0x03 ) << 10 ) ) + 1
+		);
+	}
+
+	/**
+	 * Decodes an extended chunk header
+	 * @param string $header Header string
+	 * @return boolean|array See WebPHandler::decodeHeader
+	 */
+	public static function decodeExtendedChunkHeader( $header ) {
+		// Bytes 0-3 are 'VP8X'
+		// Byte 4-7 are chunk length
+		// Byte 8-11 are a flag bytes
+		$flags = unpack( 'c', substr( $header, 8, 1 ) );
+
+		// Byte 12-17 are image size (24 bits)
+		$width = unpack( 'V', substr( $header, 12, 3 ) . "\x00" );
+		$height = unpack( 'V', substr( $header, 15, 3 ) . "\x00" );
+
+		return array(
+			'compression' => 'unknown',
+			'animated' => ( $flags[1] & self::VP8X_ANIM ) == self::VP8X_ANIM,
+			'transparency' => ( $flags[1] & self::VP8X_ALPHA ) == self::VP8X_ALPHA,
+			'width' => ( $width[1] & 0xFFFFFF ) + 1,
+			'height' => ( $height[1] & 0xFFFFFF ) + 1
+		);
+	}
+
+	public function getImageSize( $file, $path, $metadata = false ) {
+		if ( $file === null ) {
+			$metadata = self::getMetadata( $file, $path );
+		}
+		if ( $metadata === false ) {
+			$metadata = $file->getMetadata();
+		}
+
+		wfSuppressWarnings();
+		$metadata = unserialize( $metadata );
+		wfRestoreWarnings();
+
+		if ( $metadata == false ) {
+			return false;
+		}
+		return array( $metadata['width'], $metadata['height'] );
+	}
+
+	/**
+	 * @param $file
+	 * @return bool True, not all browsers support WebP
+	 */
+	public function mustRender( $file ) {
+		return true;
+	}
+
+	/**
+	 * @param $file
+	 * @return bool False if we are unable to render this image
+	 */
+	public function canRender( $file ) {
+		if ( self::isAnimatedImage( $file ) ) {
+			return false;
+		}
+		return true;
+	}
+
+	/**
+	 * @param File $image
+	 * @return bool
+	 */
+	public function isAnimatedImage( $image ) {
+		$ser = $image->getMetadata();
+		if ( $ser ) {
+			$metadata = unserialize( $ser );
+			if ( isset( $metadata['animated'] ) && $metadata['animated'] === true ) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	public function canAnimateThumbnail( $file ) {
+		return false;
+	}
+
+	/**
+	 * Render files as PNG
+	 *
+	 * @param $ext
+	 * @param $mime
+	 * @param $params
+	 * @return array
+	 */
+	public function getThumbType( $ext, $mime, $params = null ) {
+		return array( 'png', 'image/png' );
+	}
+
+	/**
+	 * Must use "im" for XCF
+	 *
+	 * @return string
+	 */
+	protected function getScalerType( $dstPath, $checkDstPath = true ) {
+		return 'im';
+	}
+}