Video CD uses MPEG-1 for video compression and .DAT as the file extension.
A streaming technology developed by RealNetworks for transmitting live video over the Internet. RealVideo uses a variety of data compression techniques and works with both normal IP connections as well as IP Multicast connections.
More information is available on RealNetwork web site.
To convert other video formats to RealMedia, you will need River Past RealMedia Booster Pack in addition to your video software.
River Past Video Cleaner