PictureHtmlSupport

The PictureHtmlSupport extension wraps MediaWiki thumbnails on wiki page with <picture> elements and allow the user to add additional <source> elements within <picture>.

Installation

1. Add the following line to LocalSettings.php:

   wfLoadExtension( 'PictureHtmlSupport' );

2. Replace includes/media/ThumbnailImage.php (make a backup!) with includes/ThumbnailImage.php from this extension.