gistfile1.txt

add_filter( 'get_comment_text', 'add_post_oembed_comment_support', 0 );
function add_post_oembed_comment_support( $comment_text ) {
	global $wp_embed;
	if ( $wp_embed ) {
		return $wp_embed->autoembed( $comment_text );
	}
	return $comment_text;
}