Recently I've got to play with Fabrice Bellard's low cost analog and digital tv modulator.
It took me a while to get it working, it didn't work with nvidia cards so I've tested a ATI Radeon 9200, like Fabrice mentiones on his webpage. What Fabrice doesn't say is that you need to use "radeon" driver, not vesa, not ati.
I've used a Pinnacle 320e receiver, which can scan the two DVB-T channels but no preview.
That was sad, I was expecting it to work, but now that it doesn't work, how to debug it? you can't, Fabrice didn't publish the source code.