If you want to be able to stream from a DVB card (a satellite card or a digital terrestial TV card), you need to install the DVB drivers:
if you use a Linux 2.6.x kernel, you just need to compile the right modules ;
if you are using a Linux 2.4.x kernel, you must download the latest release of the DVB drivers from the DVB drivers download page of the LinuxTV Project.
Uncompress the tarball and follow the instructions
written in the INSTALL file to compile and install
the drivers
.