解析獲取優酷視頻真實下載地址的PHP源代碼

代碼如下:
<?php
//--調用方法/demo.php?url=http://v.youku.com/v_show/id_XMzkyODA2NTEy.html
echo getYoukuFlv($_GET['url']);

function getYoukuFlv($url){
preg_match("#id_(.*?).html#",$url,$out);
$id=$out[1];
$content=get_curl_contents('http://v.youku.com/player/getPlayList/VideoIDS/'.$id);
$data=json_decode($content);
foreach($data->data[0]->streamfileids AS $k=>$v){
$sid=getSid();
$fileid=getfileid($v,$data->data[0]->seed);
$one=($data->data[0]->segs->$k);
if($k == 'flv' || $k == 'mp4') return "http://f.youku.com/player/getFlvPath/sid/{$sid}_00/st/{$k}/fileid/{$fileid}?K={$one[0]->k}";
continue;
}
}
function get_curl_contents($url, $second = 5){
if(!function_exists('curl_init')) die('php.ini未開啟php_curl.dll');
$c = curl_init();
curl_setopt($c,CURLOPT_URL,$url);
$UserAgent=$_SERVER['HTTP_USER_AGENT'];
curl_setopt($c,CURLOPT_USERAGENT,$UserAgent);
curl_setopt($c,CURLOPT_HEADER,0);
curl_setopt($c,CURLOPT_TIMEOUT,$second);
curl_setopt($c,CURLOPT_RETURNTRANSFER, true);
$cnt = curl_exec($c);
$cnt=mb_check_encoding($cnt,'utf-8')?iconv('gbk','utf-8//IGNORE',$cnt):$cnt; //字符編碼轉換
curl_close($c);
return $cnt;
}
function getSid() {
$sid = time().(rand(0,9000)+10000);
return $sid;
}
function getkey($key1,$key2){
$a = hexdec($key1);
$b = $a ^ 0xA55AA5A5;
$b = dechex($b);
return $key2.$b;
}
function getfileid($fileId,$seed) {
$mixed = getMixString($seed);
$ids = explode("*",$fileId);
unset($ids[count($ids)-1]);
$realId = "";
for ($i=0;$i < count($ids);++$i) {
$idx = $ids[$i];
$realId .= substr($mixed,$idx,1);
}
return $realId;
}
function getMixString($seed) {
$mixed = "";
$source = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ/:._-1234567890";
$len = strlen($source);
for($i=0;$i< $len;++$i){
$seed = ($seed * 211 + 30031) % 65536;
$index = ($seed / 65536 * strlen($source));
$c = substr($source,$index,1);
$mixed .= $c;
$source = str_replace($c, "",$source);
}
return $mixed;
}
?>