To copy-protect a video file, the best way to accomplish it used to be apply DRM to it. That way you can restrict how may times it should play or how long it should be available to the user, but that still could be broken via a lot of means.
You cannot make any video 100% copy protected. Please read the article below. If that was the case, the hollywood movies wouldnt be freely available via the torrent networks.
http://www.streamingmedia.com/Articles/Editorial/Featured-Articles/DRM-Is-Dead-79353.aspx