The Media Library accepts files in the following formats: .mov, .avi, .wmv, .flv, .mpg, .mp4, .mp3, .wav, .wma so it will probably not be necessary to convert the video.  If it should happen that your video is in a different format, there is a video converter available from AnySoft which is pretty good and easy to use. You can download a trial version here http://www.anvsoft.com/download-any-video-converter.html but the completely free version is installed on MyUHI.