It is an old format which usually is low quality. The format's development ceased in 1997, if I remember correctly.
Try this URL, if you insist on using such format.
http://egg.real.com/vivo-player/vivodl.html
(Since its development already ceased quite some time ago, I don't know of any ready methods to convert this format to others. One possible solution is to use screen capturing tools like Camtasia to capture the playback as video.)
