Re: Linux + HDCP
As mentioned previously, HDCP shouldn't be an issue for you. The way it is supposed to work is that the TV should accept any valid signal and display it, HDCP or not. Consumer electronics like HD-DVD players are supposed to downgrade the signal if they can't send it with HDCP--it's all on the sending side. (There are rumors of TVs that will downscale without HDCP, but none have been confirmed as far as I know. Most have been proven to be user confusion based on downscaling policies at the video source.)
I would start by sending a standard ATSC 720p signal, even if the native resolution is 1080i. Your TV should automatically scale it.
Then try to get 1080i working. Unfortunately, the nVidia drivers have lots of problems with interlaced modes. If you get a valid 1080i mode from the TV's EDID information, it should work with the 8776 drivers, but it will display as 1920x540 with newer drivers (even though it tells X that it's 1920x1080). Getting the right options and modeline to display 1080i with 9xxx and 100.* drivers is a black art. [There's a thread on "1080i" discussing these problems.]