string(253) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=u%E7%9B%98%E7%9A%84%E6%A0%BC%E5%BC%8F%E6%80%8E%E4%B9%88%E8%BD%AC%E6%8D%A2%E6%88%90mp4 => Failed to connect to 101.89.117.144 port 38005: Connection refused"
u盘的格式怎么转换成mp4
