No spaces or separation. For example, if the username is admin and pw is dlinkdlink. IP is 192.168.0.100.
http://admin:dlinkdlink@192.168.0.100/video1.mjpg
You may wanna try - http://192.168.0.100/video/mjpg.cgi
80 is the default port. In the web UI of the camera you can change the http port to something else. If you change it, you will need to add it to the URL after the IP address (separate it with a : ) - http://192.168.0.100:5000/video/mjpg.cgi 5000 being the new port.