Functions to use Youtube

utils.youtube.php

<?php
function youtube_image_url($id, $which=false){
	$server = rand(1,5);
	if ($server===5) {
		$url = "http://img.youtube.com/vi/{$id}/";
	} else {
		$url = "http://i{$server}.ytimg.com/vi/{$id}/";
	}
	switch ($which) {
		case 0:
			$url .= "0.jpg";
			break;
		case 1:
			$url .= "1.jpg";
			break;
		case 2:
			$url .= "2.jpg";
			break;
		case 3:
			$url .= "3.jpg";
			break;
		case 'med':
			$url .= "mqdefault.jpg";
			break;
		case 'high':
			$url .= "hqdefault.jpg";
			break;
		case 'max':
			$url .= "maxresdefault.jpg";
			break;        
		default:
			$url .= "default.jpg";
			break;
	}
	return $url;
}

function get_youtube_id( $fonte='' ) {
	preg_match( '~
	# Match non-linked youtube URL in the wild. (Rev:20110825)
	https?://               # Required scheme. Either http or https.
	(?:www\.)?              # Optional www subdomain.
	(?:                 # Group host alternatives.
		youtu\.be/          # Either youtu.be,
		| youtube\.com          # or youtube.com followed by
		\S*             # Allow anything up to VIDEO_ID,
		[^\w\-\s]           # but char before ID is non-ID char.
	)                   # End host alternatives.
	v=([\w\-]{11})              # $1: VIDEO_ID is exactly 11 chars, and is on the "v" arg
	(?=[^\w\-]|$)               # Assert next char is non-ID or EOS.
	(?!                 # Assert URL is not pre-linked.
		[?=&+%\w]*          # Allow URL (query) remainder.
		(?:             # Group pre-linked alternatives.
			[\'"][^<>]*>        # Either inside a start tag,
			| </a>          # or inside <a> element text contents.
		)               # End recognized pre-linked alts.
	)                   # End negative lookahead assertion.
	[?=&+%\w]*              # Consume any URL (query) remainder.
	~ix', $fonte, $youtube );

	if(!empty($youtube[0]))
		return $youtube[1];
	else
		return false;
}