Here’s a great article that explains the bandwidth problems cable and satellite providers face when it comes to delivering HDTV.
Decoding the source signal of an HD channel and re-encoding it at a lower bitrate for distribution to customers is common practice in the cable and satellite industry. There’s just not enough capacity on current systems to deliver a virgin HD signal from a content creator without doing some downsampling.
How much downsampling a provider can get away with is governed by things like satellite capacity and minimum bitrate guarantees written into carriage agreements. And, to a lesser degree, customer rage.
Some guy in California is suing DirecTV in a class-action suit, claiming that DirecTV went too far in compressing their HD channels and the resulting reduced-bitrate broadcasts with their visual artifacts and macroblocks could not be considered high-definition. That’s pretty sweet and I hope he wins because DirecTV is run by a bunch of jerks who have a tendency to sue anything that moves.
The article suggests that the only solutions in sight are a switch to MPEG-4, the launch of more satellites, and the replacement of cable company head-end equipment and set-top boxes. All of this will take time and quite a bit of money. Meanwhile the American appetite for HD content continues to grow and new HD channels are launching all the time!
I don’t even have an HDTV but I’ve always found this stuff interesting. Behold my nerdism.