YouTube Sidebar (no funciona)

// Add Shortcode
function video_concreto( $atts ) {

	// Attributes
	$atts = shortcode_atts(
		array(
			'videoconc' => 'https://www.youtube.com/embed/videoseries?list=PLLpdMTXxdF858K37CMXeQo0GKhGLiW4aW',
		),
		$atts,
		'canal_youtube'
	);

	// Si está lleno, muestra el vídeo del customfield canal_youtube; si no, el canal entero
	$barra_video = get_post_custom_values( 'canal_youtube' );
	if ( isset( $atts['videoconc'] ) ) {
		return '<iframe width="360" height="203" src="' . $barra_video . '" frameborder="0" allowfullscreen></iframe>';
	}
	else {
	    return '<iframe width="360" height="203" src="https://www.youtube.com/embed/videoseries?list=PLLpdMTXxdF858K37CMXeQo0GKhGLiW4aW" frameborder="0" allowfullscreen></iframe>';
	}

}
add_shortcode( 'canal_youtube', 'video_concreto' );