解析多视频网站视频,获取视频截图$urls[]="http://v.youku.com/v_show/id_XMjI4MDM4NDc2.html";*$urls[]="http://www.tudou.com/playlist/p/l13087099.html";*$urls[]="http://www.tudou.com/programs/view/ufg-A3tlcxk/";*$urls[]="http://v.ku6.com/special/show_4926690/Klze2mhMeSK6g05X.html";*$urls[]=