Implement extension registration from an extension.json file

[mediawiki.git] / includes / media / Bitmap.php

<?php
/**
 * Generic handler for bitmap images.
 *
 * 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
 */

/**
 * Generic handler for bitmap images
 *
 * @ingroup Media
 */
class BitmapHandler extends TransformationalImageHandler {

        /**
         * Returns which scaler type should be used. Creates parent directories
         * for $dstPath and returns 'client' on error
         *
         * @param string $dstPath
         * @param bool $checkDstPath
         * @return string|Callable One of client, im, custom, gd, imext or an array( object, method )
         */
        protected function getScalerType( $dstPath, $checkDstPath = true ) {
                global $wgUseImageResize, $wgUseImageMagick, $wgCustomConvertCommand;

                if ( !$dstPath && $checkDstPath ) {
                        # No output path available, client side scaling only
                        $scaler = 'client';
                } elseif ( !$wgUseImageResize ) {
                        $scaler = 'client';
                } elseif ( $wgUseImageMagick ) {
                        $scaler = 'im';
                } elseif ( $wgCustomConvertCommand ) {
                        $scaler = 'custom';
                } elseif ( function_exists( 'imagecreatetruecolor' ) ) {
                        $scaler = 'gd';
                } elseif ( class_exists( 'Imagick' ) ) {
                        $scaler = 'imext';
                } else {
                        $scaler = 'client';
                }

                return $scaler;
        }

        /**
         * Transform an image using ImageMagick
         *
         * @param File $image File associated with this thumbnail
         * @param array $params Array with scaler params
         *
         * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
         */
        protected function transformImageMagick( $image, $params ) {
                # use ImageMagick
                global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea,
                        $wgImageMagickTempDir, $wgImageMagickConvertCommand;

                $quality = array();
                $sharpen = array();
                $scene = false;
                $animation_pre = array();
                $animation_post = array();
                $decoderHint = array();
                if ( $params['mimeType'] == 'image/jpeg' ) {
                        $qualityVal = isset( $params['quality'] ) ? (string)$params['quality'] : null;
                        $quality = array( '-quality', $qualityVal ?: '80' ); // 80%
                        # Sharpening, see bug 6193
                        if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
                                / ( $params['srcWidth'] + $params['srcHeight'] )
                                < $wgSharpenReductionThreshold
                        ) {
                                $sharpen = array( '-sharpen', $wgSharpenParameter );
                        }
                        if ( version_compare( $this->getMagickVersion(), "6.5.6" ) >= 0 ) {
                                // JPEG decoder hint to reduce memory, available since IM 6.5.6-2
                                $decoderHint = array( '-define', "jpeg:size={$params['physicalDimensions']}" );
                        }
                } elseif ( $params['mimeType'] == 'image/png' ) {
                        $quality = array( '-quality', '95' ); // zlib 9, adaptive filtering

                } elseif ( $params['mimeType'] == 'image/gif' ) {
                        if ( $this->getImageArea( $image ) > $wgMaxAnimatedGifArea ) {
                                // Extract initial frame only; we're so big it'll
                                // be a total drag. :P
                                $scene = 0;
                        } elseif ( $this->isAnimatedImage( $image ) ) {
                                // Coalesce is needed to scale animated GIFs properly (bug 1017).
                                $animation_pre = array( '-coalesce' );
                                // We optimize the output, but -optimize is broken,
                                // use optimizeTransparency instead (bug 11822)
                                if ( version_compare( $this->getMagickVersion(), "6.3.5" ) >= 0 ) {
                                        $animation_post = array( '-fuzz', '5%', '-layers', 'optimizeTransparency' );
                                }
                        }
                } elseif ( $params['mimeType'] == 'image/x-xcf' ) {
                        // Before merging layers, we need to set the background
                        // to be transparent to preserve alpha, as -layers merge
                        // merges all layers on to a canvas filled with the
                        // background colour. After merging we reset the background
                        // to be white for the default background colour setting
                        // in the PNG image (which is used in old IE)
                        $animation_pre = array(
                                '-background', 'transparent',
                                '-layers', 'merge',
                                '-background', 'white',
                        );
                        wfSuppressWarnings();
                        $xcfMeta = unserialize( $image->getMetadata() );
                        wfRestoreWarnings();
                        if ( $xcfMeta
                                && isset( $xcfMeta['colorType'] )
                                && $xcfMeta['colorType'] === 'greyscale-alpha'
                                && version_compare( $this->getMagickVersion(), "6.8.9-3" ) < 0
                        ) {
                                // bug 66323 - Greyscale images not rendered properly.
                                // So only take the "red" channel.
                                $channelOnly = array( '-channel', 'R', '-separate' );
                                $animation_pre = array_merge( $animation_pre, $channelOnly );
                        }
                }

                // Use one thread only, to avoid deadlock bugs on OOM
                $env = array( 'OMP_NUM_THREADS' => 1 );
                if ( strval( $wgImageMagickTempDir ) !== '' ) {
                        $env['MAGICK_TMPDIR'] = $wgImageMagickTempDir;
                }

                $rotation = isset( $params['disableRotation'] ) ? 0 : $this->getRotation( $image );
                list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );

                $cmd = call_user_func_array( 'wfEscapeShellArg', array_merge(
                        array( $wgImageMagickConvertCommand ),
                        $quality,
                        // Specify white background color, will be used for transparent images
                        // in Internet Explorer/Windows instead of default black.
                        array( '-background', 'white' ),
                        $decoderHint,
                        array( $this->escapeMagickInput( $params['srcPath'], $scene ) ),
                        $animation_pre,
                        // For the -thumbnail option a "!" is needed to force exact size,
                        // or ImageMagick may decide your ratio is wrong and slice off
                        // a pixel.
                        array( '-thumbnail', "{$width}x{$height}!" ),
                        // Add the source url as a comment to the thumb, but don't add the flag if there's no comment
                        ( $params['comment'] !== ''
                                ? array( '-set', 'comment', $this->escapeMagickProperty( $params['comment'] ) )
                                : array() ),
                        array( '-depth', 8 ),
                        $sharpen,
                        array( '-rotate', "-$rotation" ),
                        $animation_post,
                        array( $this->escapeMagickOutput( $params['dstPath'] ) ) ) );

                wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
                wfProfileIn( 'convert' );
                $retval = 0;
                $err = wfShellExecWithStderr( $cmd, $retval, $env );
                wfProfileOut( 'convert' );

                if ( $retval !== 0 ) {
                        $this->logErrorForExternalProcess( $retval, $err, $cmd );

                        return $this->getMediaTransformError( $params, "$err\nError code: $retval" );
                }

                return false; # No error
        }

        /**
         * Transform an image using the Imagick PHP extension
         *
         * @param File $image File associated with this thumbnail
         * @param array $params Array with scaler params
         *
         * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
         */
        protected function transformImageMagickExt( $image, $params ) {
                global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea;

                try {
                        $im = new Imagick();
                        $im->readImage( $params['srcPath'] );

                        if ( $params['mimeType'] == 'image/jpeg' ) {
                                // Sharpening, see bug 6193
                                if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
                                        / ( $params['srcWidth'] + $params['srcHeight'] )
                                        < $wgSharpenReductionThreshold
                                ) {
                                        // Hack, since $wgSharpenParameter is written specifically for the command line convert
                                        list( $radius, $sigma ) = explode( 'x', $wgSharpenParameter );
                                        $im->sharpenImage( $radius, $sigma );
                                }
                                $qualityVal = isset( $params['quality'] ) ? (string)$params['quality'] : null;
                                $im->setCompressionQuality( $qualityVal ?: 80 );
                        } elseif ( $params['mimeType'] == 'image/png' ) {
                                $im->setCompressionQuality( 95 );
                        } elseif ( $params['mimeType'] == 'image/gif' ) {
                                if ( $this->getImageArea( $image ) > $wgMaxAnimatedGifArea ) {
                                        // Extract initial frame only; we're so big it'll
                                        // be a total drag. :P
                                        $im->setImageScene( 0 );
                                } elseif ( $this->isAnimatedImage( $image ) ) {
                                        // Coalesce is needed to scale animated GIFs properly (bug 1017).
                                        $im = $im->coalesceImages();
                                }
                        }

                        $rotation = isset( $params['disableRotation'] ) ? 0 : $this->getRotation( $image );
                        list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );

                        $im->setImageBackgroundColor( new ImagickPixel( 'white' ) );

                        // Call Imagick::thumbnailImage on each frame
                        foreach ( $im as $i => $frame ) {
                                if ( !$frame->thumbnailImage( $width, $height, /* fit */ false ) ) {
                                        return $this->getMediaTransformError( $params, "Error scaling frame $i" );
                                }
                        }
                        $im->setImageDepth( 8 );

                        if ( $rotation ) {
                                if ( !$im->rotateImage( new ImagickPixel( 'white' ), 360 - $rotation ) ) {
                                        return $this->getMediaTransformError( $params, "Error rotating $rotation degrees" );
                                }
                        }

                        if ( $this->isAnimatedImage( $image ) ) {
                                wfDebug( __METHOD__ . ": Writing animated thumbnail\n" );
                                // This is broken somehow... can't find out how to fix it
                                $result = $im->writeImages( $params['dstPath'], true );
                        } else {
                                $result = $im->writeImage( $params['dstPath'] );
                        }
                        if ( !$result ) {
                                return $this->getMediaTransformError( $params,
                                        "Unable to write thumbnail to {$params['dstPath']}" );
                        }
                } catch ( ImagickException $e ) {
                        return $this->getMediaTransformError( $params, $e->getMessage() );
                }

                return false;
        }

        /**
         * Transform an image using a custom command
         *
         * @param File $image File associated with this thumbnail
         * @param array $params Array with scaler params
         *
         * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
         */
        protected function transformCustom( $image, $params ) {
                # Use a custom convert command
                global $wgCustomConvertCommand;

                # Variables: %s %d %w %h
                $src = wfEscapeShellArg( $params['srcPath'] );
                $dst = wfEscapeShellArg( $params['dstPath'] );
                $cmd = $wgCustomConvertCommand;
                $cmd = str_replace( '%s', $src, str_replace( '%d', $dst, $cmd ) ); # Filenames
                $cmd = str_replace( '%h', wfEscapeShellArg( $params['physicalHeight'] ),
                        str_replace( '%w', wfEscapeShellArg( $params['physicalWidth'] ), $cmd ) ); # Size
                wfDebug( __METHOD__ . ": Running custom convert command $cmd\n" );
                wfProfileIn( 'convert' );
                $retval = 0;
                $err = wfShellExecWithStderr( $cmd, $retval );
                wfProfileOut( 'convert' );

                if ( $retval !== 0 ) {
                        $this->logErrorForExternalProcess( $retval, $err, $cmd );

                        return $this->getMediaTransformError( $params, $err );
                }

                return false; # No error
        }

        /**
         * Transform an image using the built in GD library
         *
         * @param File $image File associated with this thumbnail
         * @param array $params Array with scaler params
         *
         * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
         */
        protected function transformGd( $image, $params ) {
                # Use PHP's builtin GD library functions.
                #
                # First find out what kind of file this is, and select the correct
                # input routine for this.

                $typemap = array(
                        'image/gif' => array( 'imagecreatefromgif', 'palette', false, 'imagegif' ),
                        'image/jpeg' => array( 'imagecreatefromjpeg', 'truecolor', true,
                                array( __CLASS__, 'imageJpegWrapper' ) ),
                        'image/png' => array( 'imagecreatefrompng', 'bits', false, 'imagepng' ),
                        'image/vnd.wap.wbmp' => array( 'imagecreatefromwbmp', 'palette', false, 'imagewbmp' ),
                        'image/xbm' => array( 'imagecreatefromxbm', 'palette', false, 'imagexbm' ),
                );

                if ( !isset( $typemap[$params['mimeType']] ) ) {
                        $err = 'Image type not supported';
                        wfDebug( "$err\n" );
                        $errMsg = wfMessage( 'thumbnail_image-type' )->text();

                        return $this->getMediaTransformError( $params, $errMsg );
                }
                list( $loader, $colorStyle, $useQuality, $saveType ) = $typemap[$params['mimeType']];

                if ( !function_exists( $loader ) ) {
                        $err = "Incomplete GD library configuration: missing function $loader";
                        wfDebug( "$err\n" );
                        $errMsg = wfMessage( 'thumbnail_gd-library', $loader )->text();

                        return $this->getMediaTransformError( $params, $errMsg );
                }

                if ( !file_exists( $params['srcPath'] ) ) {
                        $err = "File seems to be missing: {$params['srcPath']}";
                        wfDebug( "$err\n" );
                        $errMsg = wfMessage( 'thumbnail_image-missing', $params['srcPath'] )->text();

                        return $this->getMediaTransformError( $params, $errMsg );
                }

                $src_image = call_user_func( $loader, $params['srcPath'] );

                $rotation = function_exists( 'imagerotate' ) && !isset( $params['disableRotation'] ) ? $this->getRotation( $image ) : 0;
                list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
                $dst_image = imagecreatetruecolor( $width, $height );

                // Initialise the destination image to transparent instead of
                // the default solid black, to support PNG and GIF transparency nicely
                $background = imagecolorallocate( $dst_image, 0, 0, 0 );
                imagecolortransparent( $dst_image, $background );
                imagealphablending( $dst_image, false );

                if ( $colorStyle == 'palette' ) {
                        // Don't resample for paletted GIF images.
                        // It may just uglify them, and completely breaks transparency.
                        imagecopyresized( $dst_image, $src_image,
                                0, 0, 0, 0,
                                $width, $height,
                                imagesx( $src_image ), imagesy( $src_image ) );
                } else {
                        imagecopyresampled( $dst_image, $src_image,
                                0, 0, 0, 0,
                                $width, $height,
                                imagesx( $src_image ), imagesy( $src_image ) );
                }

                if ( $rotation % 360 != 0 && $rotation % 90 == 0 ) {
                        $rot_image = imagerotate( $dst_image, $rotation, 0 );
                        imagedestroy( $dst_image );
                        $dst_image = $rot_image;
                }

                imagesavealpha( $dst_image, true );

                $funcParams = array( $dst_image, $params['dstPath'] );
                if ( $useQuality && isset( $params['quality'] ) ) {
                        $funcParams[] = $params['quality'];
                }
                call_user_func_array( $saveType, $funcParams );

                imagedestroy( $dst_image );
                imagedestroy( $src_image );

                return false; # No error
        }

        /**
         * Callback for transformGd when transforming jpeg images.
         */
        // FIXME: transformImageMagick() & transformImageMagickExt() uses JPEG quality 80, here it's 95?
        static function imageJpegWrapper( $dst_image, $thumbPath, $quality = 95 ) {
                imageinterlace( $dst_image );
                imagejpeg( $dst_image, $thumbPath, $quality );
        }

        /**
         * Returns whether the current scaler supports rotation (im and gd do)
         *
         * @return bool
         */
        public function canRotate() {
                $scaler = $this->getScalerType( null, false );
                switch ( $scaler ) {
                        case 'im':
                                # ImageMagick supports autorotation
                                return true;
                        case 'imext':
                                # Imagick::rotateImage
                                return true;
                        case 'gd':
                                # GD's imagerotate function is used to rotate images, but not
                                # all precompiled PHP versions have that function
                                return function_exists( 'imagerotate' );
                        default:
                                # Other scalers don't support rotation
                                return false;
                }
        }

        /**
         * @see $wgEnableAutoRotation
         * @return bool Whether auto rotation is enabled
         */
        public function autoRotateEnabled() {
                global $wgEnableAutoRotation;

                if ( $wgEnableAutoRotation === null ) {
                        // Only enable auto-rotation when we actually can
                        return $this->canRotate();
                }

                return $wgEnableAutoRotation;
        }

        /**
         * @param File $file
         * @param array $params Rotate parameters.
         *   'rotation' clockwise rotation in degrees, allowed are multiples of 90
         * @since 1.21
         * @return bool
         */
        public function rotate( $file, $params ) {
                global $wgImageMagickConvertCommand;

                $rotation = ( $params['rotation'] + $this->getRotation( $file ) ) % 360;
                $scene = false;

                $scaler = $this->getScalerType( null, false );
                switch ( $scaler ) {
                        case 'im':
                                $cmd = wfEscapeShellArg( $wgImageMagickConvertCommand ) . " " .
                                        wfEscapeShellArg( $this->escapeMagickInput( $params['srcPath'], $scene ) ) .
                                        " -rotate " . wfEscapeShellArg( "-$rotation" ) . " " .
                                        wfEscapeShellArg( $this->escapeMagickOutput( $params['dstPath'] ) );
                                wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
                                wfProfileIn( 'convert' );
                                $retval = 0;
                                $err = wfShellExecWithStderr( $cmd, $retval );
                                wfProfileOut( 'convert' );
                                if ( $retval !== 0 ) {
                                        $this->logErrorForExternalProcess( $retval, $err, $cmd );

                                        return new MediaTransformError( 'thumbnail_error', 0, 0, $err );
                                }

                                return false;
                        case 'imext':
                                $im = new Imagick();
                                $im->readImage( $params['srcPath'] );
                                if ( !$im->rotateImage( new ImagickPixel( 'white' ), 360 - $rotation ) ) {
                                        return new MediaTransformError( 'thumbnail_error', 0, 0,
                                                "Error rotating $rotation degrees" );
                                }
                                $result = $im->writeImage( $params['dstPath'] );
                                if ( !$result ) {
                                        return new MediaTransformError( 'thumbnail_error', 0, 0,
                                                "Unable to write image to {$params['dstPath']}" );
                                }

                                return false;
                        default:
                                return new MediaTransformError( 'thumbnail_error', 0, 0,
                                        "$scaler rotation not implemented" );
                }
        }
}