Youtube get thumnail from url

getYoutubeThumbnail.php

<?php
function getThumb($url, $size="big") {
        $size = (size === null) ? "big" : $size;
        $p = "/([\\?&])v=([^&#]*)/i";
	// you can use parse_str to get video id
        if(preg_match($p,$url,$results)){
			$vid = $results[2];
			if (size == "small") {
				return "http://img.youtube.com/vi/" . $vid . "/2.jpg";
			} else {
				return "http://img.youtube.com/vi/" . $vid . "/0.jpg";
			}
		}
}