you need some way to connect audio and video from the tv and convert it to digital. Here are the three best ways:
1. get a pc card that will take in the three cables: audio(mono) audio(sterio) and video
2. if it is a laptop, it should have an s-video connection and if you are lucky, your tv will also have an s-video connection, just buy the cable.
3. buy some sort of converter cable