Tv playing software under linux

so far I have used several tv playing software under linux os. There are some software like tvtime, zapping, mplayer, mythtv(with many strong functions), mpegtv(haven't used it), xawtv,bttv(haven't used it), my task is to analysize their source code and to implement same functions or more new features. It is a difficult work for me because I haven't knewn anything about them before, so I have to spend my most time studying them and write some test code to realize some features.
Good luck to me...