Filtering wp title not working

I use some custom post type and tried to use this to create a seo friendly title. I added this in function.php of my theme but does not works. anybody please tell my what’s wrong here.

add_filter( 'wp_title', 'bd_wp_title', 10, 2 );
function bd_wp_title( $title, $sep ) {
	global $paged, $page;
	if (is_singular( 'videos' )) {
		$title = ''. get_the_title() .' '. strip_tags(get_the_term_list( get_the_ID(), 'video-categories', '', ' ', '' )) .' Download HD Mp4, 3GP Mobile';
	}
	return $title;
	if (is_singular( 'albums' )) {
		$title = ''. get_the_title() .' Bangla Mp3 '. strip_tags(get_the_term_list( get_the_ID(), 'genre', '', ' ', '' )) .' Free download';
	}
	return $title;
}