PHP做youtube 下载链接生成器

youtube 下载链接生成器
使用下面的 PHP 片段可以让你的用户下载 Youtube 视频

function str_between($string, $start, $end)
{
$string = " ".$string; $ini = strpos($string,$start); if ($ini == 0) return ""; $ini += strlen($start); $len = strpos($string,$end,$ini) - $ini; return substr($string,$ini,$len); }
function get_youtube_download_link(){
    $youtube_link = $_GET['youtube'];
    $youtube_page = file_get_contents($youtube_link);
    $v_id = str_between($youtube_page, "&video_id=", "&");
    $t_id = str_between($youtube_page, "&t=", "&");
    $flv_link = "http://www.youtube.com/get_video?video_id=$v_id&t=$t_id";
    $hq_flv_link = "http://www.youtube.com/get_video?video_id=$v_id&t=$t_id&fmt=6";
    $mp4_link = "http://www.youtube.com/get_video?video_id=$v_id&t=$t_id&fmt=18";
    $threegp_link = "http://www.youtube.com/get_video?video_id=$v_id&t=$t_id&fmt=17";
    echo "\t\tDownload (right-click > save as):\n\t\t";
    echo "<a href=\"$flv_link\">FLV</a>\n\t\t";
    echo "<a href=\"$hq_flv_link\">HQ FLV (if available)</a>\n\t\t";
    echo "<a href=\"$mp4_link\">MP4</a>\n\t\t";
    echo "<a href=\"$threegp_link\">3GP</a>\n";
}