dear all,
i want to build applet viewing video from an ip camera which gives video type MPEG-4.
how can i build that application?which api i need to work with?

You need to post some code before people will help you. Read the announcment at the top of the forum.

dear all,
i want to build applet viewing video from an ip camera which gives video type MPEG-4.
how can i build that application?

By coding it?

which api i need to work with?

Well, if you're going to use Java, I would say to start with the JDK.

i know how capture video from webcam and usb cam. but, i do not know how to detect the ip camera on the network and capture video from IP Camera.how do you want me to send some code and i do not know how to start with it ?
i asked for some help and advices and i did not ask for writting code.
please , provide links can i refer to know more about

It was the way you worded your question. The way you said it left no way to help you. Your problem now is networking and has almost nothing to do with the camera. First, start with the networking tutorial and the cameras manual.