CamStudio was implemented only for Windows operating system and it's not supported on UNIX/Linux.
But, there are plenty of other applications, which you can use in order to perform screen recordings and captures under Linux. recordMyDesktop is an open-source application that was designed with such purpose (with the mention that it uses only open formats: theora and vorbis). A similar application is Xvidcap, which will allow you to export your recordings to mpeg format. Furthermore, if you are a GNOME desktop user, you might find Istanbul quite useful.
Nevertheless, these are just a few examples that might fit your needs. A simple search on the Web will return a lot of other options.