Got Error: could not read from resource, when connecting to a web camera

I am using jetson.utils to connect to web cameras.
The cameras are also managed by monitoring system.
I am connecting the cameras from the proxy server.
I can successfully connect to them by using VLC media player, but I got error messages in python as below.

The connection string is like: rtsp://user:password@proxyIP:port/IP=cameraIP&port=80&Username=&PWD=&Dev=48&PB=0&Channel=0

Then I set “–input-codec=h264”, I got below message:

Could you please suggest how to connect to them? Thank you.

Please refer to