string(272) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E4%B8%BA%E4%BB%80%E4%B9%88b%E7%AB%99%E4%B8%8A%E4%BC%A0%E7%9A%84%E8%A7%86%E9%A2%91%E5%8F%AA%E6%9C%89480p => Failed to connect to 125.88.227.171 port 38114: Connection refused"
为什么b站上传的视频只有480p
