mythtv allows this by default. Just follow a mythtv guide from their site to set it up on the core.
Run myth-setup under Computing on the core.
For mythtv related stuff, best place to start is here newbielink:http://www.mythtv.org/wiki/index.php/Main_Page [nonactive]
I've got a system with twin DVB-T cards to get Freeview here.