If your camera is not listed and you already tried selecting Other Camera from the Connect To network dialog then search the camera's maker homepage for the GET Request Format. Enter the found GET-COMMAND in the network dialog as an URL:
For example axis cameras use for RTSP (with default port 554):
or for HTTP jpeg snapshots (with default port 80):
and for HTTP motion jpeg (with default port 80):
Remember to replace IP with the camera's IP address.
Hint: if the camera's maker homepage is not helpful try to search the GET-COMMAND here.