$p->video now return the video link only, to get the video ID we can use get_video_id($p->video); and call it from the theme.If you are not using theme shipped with HTMLy source code, please download the updated version. If you already modify the theme and don't want your changes to be lost, simply update the <?php echo $p->video;?> to <?php echo get_video_id($p->video); ?> in main.html.php and post.html.php.