<?php
// Here is a sample of the URLs this regex matches: (there can be more content after the given URL that will be ignored)
// http://youtu.be/dQw4w9WgXcQ
// http://www.youtube.com/embed/dQw4w9WgXcQ
// http://www.youtube.com/watch?v=dQw4w9WgXcQ
// http://www.youtube.com/?v=dQw4w9WgXcQ
// http://www.youtube.com/v/dQw4w9WgXcQ
// http://www.youtube.com/e/dQw4w9WgXcQ
// http://www.youtube.com/user/username#p/u/11/dQw4w9WgXcQ
// http://www.youtube.com/sandalsResorts#p/c/54B8C800269D7C1B/0/dQw4w9WgXcQ
// http://www.youtube.com/watch?feature=player_embedded&v=dQw4w9WgXcQ
// http://www.youtube.com/?feature=player_embedded&v=dQw4w9WgXcQ
// It also works on the youtube-nocookie.com URL with the same above options.
// It will also pull the ID from the URL in an embed code (both iframe and object tags)
preg_match('%(?:youtube(?:-nocookie)?\.com/(?:[^/]+/.+/|(?:v|e(?:mbed)?)/|.*[?&]v=)|youtu\.be/)([^"&?/ ]{11})%i', $url, $match);
$youtube_id = $match[1];
?>