includes/media/ExifBitmapHandler.php
<?php
/**
* Handler for bitmap images with exif metadata.
*
* 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
*/
use MediaWiki\MainConfigNames;
use MediaWiki\MediaWikiServices;
/**
* Stuff specific to JPEG and (built-in) TIFF handler.
* All metadata related, since both JPEG and TIFF support Exif.
*
* @stable to extend
* @ingroup Media
*/
class ExifBitmapHandler extends BitmapHandler {
/** Error extracting metadata */
public const BROKEN_FILE = '-1';
/** Outdated error extracting metadata */
public const OLD_BROKEN_FILE = '0';
public function convertMetadataVersion( $metadata, $version = 1 ) {
// basically flattens arrays.
$version = is_int( $version ) ? $version : (int)explode( ';', $version, 2 )[0];
if ( $version < 1 || $version >= 2 ) {
return $metadata;
}
if ( !isset( $metadata['MEDIAWIKI_EXIF_VERSION'] ) || $metadata['MEDIAWIKI_EXIF_VERSION'] !== 2 ) {
return $metadata;
}
// Treat Software as a special case because in can contain
// an array of (SoftwareName, Version).
if ( isset( $metadata['Software'] )
&& is_array( $metadata['Software'] )
&& is_array( $metadata['Software'][0] )
&& isset( $metadata['Software'][0][0] )
&& isset( $metadata['Software'][0][1] )
) {
$metadata['Software'] = $metadata['Software'][0][0] . ' (Version '
. $metadata['Software'][0][1] . ')';
}
$formatter = new FormatMetadata;
// ContactInfo also has to be dealt with specially
if ( isset( $metadata['Contact'] ) ) {
$metadata['Contact'] = $formatter->collapseContactInfo(
is_array( $metadata['Contact'] ) ? $metadata['Contact'] : [ $metadata['Contact'] ]
);
}
// Ignore Location shown if it is not a simple string
if ( isset( $metadata['LocationShown'] ) && !is_string( $metadata['LocationShown'] ) ) {
unset( $metadata['LocationShown'] );
}
foreach ( $metadata as &$val ) {
if ( is_array( $val ) ) {
// @phan-suppress-next-line SecurityCheck-DoubleEscaped Ambiguous with the true for nohtml
$val = $formatter->flattenArrayReal( $val, 'ul', true );
}
}
unset( $val );
$metadata['MEDIAWIKI_EXIF_VERSION'] = 1;
return $metadata;
}
/**
* @param File $image
* @return bool|int
*/
public function isFileMetadataValid( $image ) {
$showEXIF = MediaWikiServices::getInstance()->getMainConfig()->get( MainConfigNames::ShowEXIF );
if ( !$showEXIF ) {
# Metadata disabled and so an empty field is expected
return self::METADATA_GOOD;
}
$exif = $image->getMetadataArray();
if ( !$exif ) {
wfDebug( __METHOD__ . ': error unserializing?' );
return self::METADATA_BAD;
}
if ( $exif === [ '_error' => self::OLD_BROKEN_FILE ] ) {
# Old special value indicating that there is no Exif data in the file.
# or that there was an error well extracting the metadata.
wfDebug( __METHOD__ . ": back-compat version" );
return self::METADATA_COMPATIBLE;
}
if ( $exif === [ '_error' => self::BROKEN_FILE ] ) {
return self::METADATA_GOOD;
}
if ( !isset( $exif['MEDIAWIKI_EXIF_VERSION'] )
|| $exif['MEDIAWIKI_EXIF_VERSION'] !== Exif::version()
) {
if ( isset( $exif['MEDIAWIKI_EXIF_VERSION'] )
&& $exif['MEDIAWIKI_EXIF_VERSION'] === 1
) {
// back-compatible but old
wfDebug( __METHOD__ . ": back-compat version" );
return self::METADATA_COMPATIBLE;
}
# Wrong (non-compatible) version
wfDebug( __METHOD__ . ": wrong version" );
return self::METADATA_BAD;
}
return self::METADATA_GOOD;
}
/**
* @param File $image
* @param IContextSource|false $context
* @return array[]|false
*/
public function formatMetadata( $image, $context = false ) {
$meta = $this->getCommonMetaArray( $image );
if ( !$meta ) {
return false;
}
return $this->formatMetadataHelper( $meta, $context );
}
public function getCommonMetaArray( File $file ) {
$exif = $file->getMetadataArray();
if ( !$exif ) {
return [];
}
unset( $exif['MEDIAWIKI_EXIF_VERSION'] );
return $exif;
}
public function getMetadataType( $image ) {
return 'exif';
}
protected function applyExifRotation( $info, $metadata ) {
if ( $this->autoRotateEnabled() ) {
$rotation = $this->getRotationForExifFromOrientation( $metadata['Orientation'] ?? null );
} else {
$rotation = 0;
}
if ( $rotation === 90 || $rotation === 270 ) {
$width = $info['width'];
$info['width'] = $info['height'];
$info['height'] = $width;
}
return $info;
}
/**
* On supporting image formats, try to read out the low-level orientation
* of the file and return the angle that the file needs to be rotated to
* be viewed.
*
* This information is only useful when manipulating the original file;
* the width and height we normally work with is logical, and will match
* any produced output views.
*
* @param File $file
* @return int 0, 90, 180 or 270
*/
public function getRotation( $file ) {
if ( !$this->autoRotateEnabled() ) {
return 0;
}
$orientation = $file->getMetadataItem( 'Orientation' );
return $this->getRotationForExifFromOrientation( $orientation );
}
/**
* Given a chunk of serialized Exif metadata, return the orientation as
* degrees of rotation.
*
* @param int|null $orientation
* @return int 0, 90, 180 or 270
* @todo FIXME: Orientation can include flipping as well; see if this is an issue!
*/
protected function getRotationForExifFromOrientation( $orientation ) {
if ( $orientation === null ) {
return 0;
}
# See http://sylvana.net/jpegcrop/exif_orientation.html
switch ( $orientation ) {
case 8:
return 90;
case 3:
return 180;
case 6:
return 270;
default:
return 0;
}
}
}