FFmpeg：方法DESCRIBE失败 - 找不到404

Question

我试图通过FFmpeg lib从我的IP摄像头播放RTSP流。

这是我的代码：

const char  *filenameSrc = "rtsp://admin:Centic.vn2018@113.176.100.223/cam/realmonitor?channel=1&subtype=0&unicast=true&proto=Onvif"; //Axis
AVDictionary *options = NULL;
av_dict_set(&options,"rtsp_flags","prefer_tcp",0);
av_dict_set(&options,"stimeout","1000000",0);
if ( avformat_open_input( &pFormatCtx, filenameSrc, NULL, &options ) != 0 ) {
        std::cout << "Open File Error 12" << std::endl;
        return -12;
    }

我收到此错误：

LBMixtureOfGaussians()
[rtsp @ 0xf22bc0] method DESCRIBE failed: 404 Not Found
Open File Error 12

有人可以帮我找到原因，提前谢谢！