To get meta value in front-end, use get_post_meta() with meta key is youtube_id.
Example:
Print YouTube video ID:
ID, ‘youtube_id’, true);?>
Thumbnails:
<img src="http://img.youtube.com/vi/ID, ‘youtube_id’, true);?>/mqdefault.jpg” alt=”” />
Video player:
<iframe src="http://www.youtube.com/embed/ID, ‘youtube_id’, true); ?>” width=”588″ height=”331″ frameborder=”0″ allowfullscreen>
