You have several options.
1. As several others have suggested - try WebRTC. Advantage is that it works on browsers (not all browsers, though) including mobile phone browsers (Chrome), without the need to install any plugins. Downside - not very stable yet. We did build a platform for communication using WebRTC earlier.
2. Use a framework like simpleWebRTC to make your development easier.
3. Use an existing product.
I think adding video to applications is exciting and more options are available. Please make sure that the option you are selecting is scaleable for your requirements.
Best of luck.