Basic question for you all.......
What's so special about mpeg4??? Is it just a more compressed format which therefore results in more bandwidth? Or is it something else? I can't imagine it would do much of anything for pic quality since that's determined by the broadcaster and your tv. So....again, what's so special about a mpeg4 rollout?
You are fundamentally correct in saying that MPEG4 results in more bandwidth. Bandwidth and PQ are related in that the amount of bandwidth available dictates the "capability" of the transmission mechanism to maintain close to the original PQ available from its source. All compression schemes are not entirely lossless, and the amount of loss can be adjusted by the encoder to take up less bandwidth by accepting more loss when the data is decoded into a picture. Newer codecs like WMV-9 (now PC-1 I think) and the newer version of MPEG4 (both accepted as standards for the HDDVD and Blu Ray HD DVD formats) can do a better job of increasing compression with less overall loss of data.
So with more bandwidth you can either carry more channels, have less loss in the information being transmitted (remember, all of the picture is encoded digitally now so it is for all practical purposes, just data), or a combination. I vote for both, but if I had to pick (and I think a lot of Voomers with large displays feel the same) I'd go for PQ.
The cool thing about Voom STBs is that they have a slot for a new decoder in addition to the MPEG2 decoder built in. Statement of direction is to go with MPEG4, but it may also be possible in the future to use another card in that slot that does one of the newer codecs for even better "capability" for increased capacity and/or PQ.
I keep putting quotes around "capability" as it it up to the folks that own the encoders as to how far they turn the dial with regards to data loss. Folks that author DVDs do the same thing, which is why we sometimes see a wide variation of PQ on that medium - excluding crappy authoring practices...
Hope that helps,