RBBrittain said:
...(a) is 8PSK necessary to enable MPEG4, and (b) will 8PSK and/or MPEG4 solve the "two-dish" problem?
8PSK is a modulation technique, a method of parsing a bitstream so it can be transported and eventually demodulated at the other end. MPEG-4 is an encoding compression technique, a method of making ones and zeros out of analog video, and then throwing away that is perceived as redundant, and then what's left is eventually decoded at the other end.
They are two very different things, barely related to each other, and separate but different steps in DBS delivery. They are two (four, actually) different parts of the process, and one does not really depend upon the other...for the most part what modulation scheme is used is independent of what encoding scheme is used, and vice versa.
After other preparation video is encoded, and the file created by that can either be recorded directly (before transportation) or streamed. It is modulated before being transmitted, then demodulated, then decoded. Two schemes, four steps.
You can have 8PSK (or not) whether you use MPEG-2, MPEG-4, or MPEG-24. You can have MPEG-4 (or not) whether you modulate it for transmission with 8PSK, 8VSB, or 16VSB. About all they have in common is that both are strategically applicable to making DBS delivery efficient, and E* is fond of both for that reason. They have minimal impact on each other, just slightly more than your gas stove has on your electric microwave oven. IOW, apples and oranges.