Get YouTube video ID from URL

extras.php

<?php
/**
 * Get the ID of a YouTube Video
**/ 
function helpwp_youtube_id($url){
	/*
	* type1: http://www.youtube.com/watch?v=9Jr6OtgiOIw
	* type2: http://www.youtube.com/watch?v=9Jr6OtgiOIw&feature=related
	* type3: http://youtu.be/9Jr6OtgiOIw
	*/
	$vid_id = "";
	$flag = false;
	if(isset($url) && !empty($url)){
		/*case1 and 2*/
		$parts = explode("?", $url);
		if(isset($parts) && !empty($parts) && is_array($parts) && count($parts)>1){
			$params = explode("&", $parts[1]);
			if(isset($params) && !empty($params) && is_array($params)){
				foreach($params as $param){
					$kv = explode("=", $param);
					if(isset($kv) && !empty($kv) && is_array($kv) && count($kv)>1){
						if($kv[0]=='v'){
							$vid_id = $kv[1];
							$flag = true;
							break;
						}
					}
				}
			}
		}
		
		/*case 3*/
		if(!$flag){
			$needle = "youtu.be/";
			$pos = null;
			$pos = strpos($url, $needle);
			if ($pos !== false) {
				$start = $pos + strlen($needle);
				$vid_id = substr($url, $start, 11);
				$flag = true;
			}
		}
	}
	return $vid_id;
}