Make cheap ATSC (or DVB) RF-modulators
As I continue to play with HDTV, I found I had a horrendous time getting good output from my computer running the MythTV open source PVR into my TV. DVI, the uncompressed digital standard, just wouldn't work from the video card I had to the TV. The TV has Firewire/1394, which would allow me to stream mpeg-2 to it, and that would be really great, but as yet no software supports it because few TVs have such inputs.
Here's another idea, one that reverses old thinking. The earliest VCRs did their outut on an RF modulator to channel 3, the only way to get into older TVs. Now we of course recommend non-RF methods, such as composite video, S-video or best of all component video/VGA, or in the digital realm, DVI and HDMI.
But in fact with TVs being mandated to have ATSC tuners, could it make sense to go back to RF? This gives digital decoding in the TV, in theory the highest quality if the TV has a good decoder. The cables are easy and super cheap, and carry digital video and 6 channel sound -- something even DVI doesn't do. You can run them as long as you want.
Plus, you can have tons of multiple inputs, just on different channels. Put your cable box on channel 3, your PVR on channel 4, DVD player on channel 5 and so on -- no need for the plethora of inputs and mass of cables.
(Don't get me wrong, I think a single ethernet jack would be better than any of these methods, but the TVs don't have them and they do have the tuners now.)
There is one big issue, however, which is on-screen display and comptuer generated menus. The RF sends a compressed mpeg stream. On the
surface, that's great because the boxes handling the video can be slow and
cheap -- they are just slinging bits they don't understand. But once you want
to overlay text on the video, you suddenly have to decode the stream (hard enough) and then re-encode it, which is close to impossible with today's hardware. On the other hand, it should be possible to do non-transparent overlays, where you take over a region of the screen (perhaps the bottom is easiest) and replace it with your generated text.
The ideal solution to this would be to modify the protocols to allow sending a second stream to be overlayed, with an alpha channel, on the main one. This is true no matter how you send compressed video -- RF, ethernet or firewire. However, we don't get to change the protocols, the idea here is to make use of something already out there.
Generating Mpeg from computer menu displays on the other hand is something that should be within the capabilities of today's CPUs. They can do it at smaller resolution (720x480 DVD res is fine) but more to the point unless there are fancy animations, it's static and machine generated and easy to set up for quick conversion.
There's no encryption, which might cause pressure to balk at this but it has a lot of advantages worth considering as kludges go.