download video youtube

<?php
$id=$a['id'];
$dt=file_get_contents("http://www.youtube.com/get_video_info?video_id=$id&asv=3&el=detailpage&hl=en_US");
$x=explode("&",$dt);
$t=array(); $g=array(); $h=array();
foreach($x as $r){
    $c=explode("=",$r);
    $n=$c[0]; $v=$c[1];
    $y=urldecode($v);
    $t[$n]=$v;
}
$streams = explode(',',urldecode($t['url_encoded_fmt_stream_map']));
foreach($streams as $dt){
    $x=explode("&",$dt);
    foreach($x as $r){
        $c=explode("=",$r);
        $n=$c[0]; $v=$c[1];
        $h[$n]=urldecode($v);
    }
    $g[]=$h;
}
//print_r($g);
echo '<div style="clear:both;margin-bottom:10px;">';
echo '<span class="vd">DOWNLOAD VIDEO</span>';
foreach($g as $format)
{
$type = explode(';',$format['type'] );
$types = $type[0];
$size = formatBytes(get_size($format['url']));
echo '<span class="vd"><a target="_blank" href="'.urldecode($format['url']).'">'.$size.'</a></span>';
}
echo '</div>';
?>