YouTube Embed plugin

<?php
/**
 * Youtube Embed Plugin
 *
 * Based on Cory Webb's Youtube Embedding plugin ( http://www.corywebbmedia.com/ )
 *
 * - improved regular expression
 * - override default width & height by adding #width,height to the youtube link
 * - don't parse youtube url inside a link
 *
 * @version     $Id: youtubeembed.php 5 2011-03-12 21:40:29Z kotuha $
 * @author      Steven Rombauts ( @kotuhaweb )
 * @email       [email protected]
 */

defined( '_JEXEC' ) or die( 'Restricted access' );

jimport( 'joomla.plugin.plugin' );

class plgContentYoutubeEmbed extends JPlugin
{

    function plgContentYoutubeEmbed(&$subject, $params)
    {
        parent::__construct($subject, $params);
    }

    function onPrepareContent(&$article, &$params, $limitstart)
    {
        if(strpos($article->text, 'http://www.youtube.com/') === false && strpos($article->text, 'http://youtube.com/') === false) {
            return;
        }

        $pattern = '/(?<!href\=\"|\')(http:\/\/w{0,3}\.{0,1}youtube\.com\/watch\?([a-zA-Z0-9=&;]+)(\#?([0-9,]+))?)/ie';

        $article->text = preg_replace($pattern,
                        '$this->getEmbedCode("\2", "\4")',
                        $article->text
                    );

        return;
    }

    function getEmbedCode($query, $hash)
    {
        $query = str_replace('&amp;', '&', $query);
        $pairs = explode('&', $query);

        $arguments = array();
        foreach($pairs as $pair)
        {
            $parts = explode('=', $pair);
            $arguments[$parts[0]] = $parts[1];
        }

        $dimension = $this->getDimension($hash);

        return '<object width="'.$dimension->width.'" height="'.$dimension->height.'"><param name="movie" value="http://www.youtube.com/v/'.$arguments['v'].'"></param><param name="allowFullScreen" value="true"></param><embed src="http://www.youtube.com/v/'.$arguments['v'].'" type="application/x-shockwave-flash" allowfullscreen="true" width="'.$dimension->width.'" height="'.$dimension->height.'"></embed></object>';
    }

    function getDimension($hash)
    {
        $plugin =& JPluginHelper::getPlugin('content', 'youtubeembed');
        $params = new JParameter( $plugin->params );

        $dimension = new stdClass();
        $dimension->width = $params->get('width', 425);
        $dimension->height = $params->get('height', 344);

        if(strpos($hash, ',') !== false)
        {
            $dimensions = explode(',', $hash);
            $dimension->width = $dimensions[0];
            $dimension->height = $dimensions[1];
        }

        return $dimension;
    }

}