geo said:
Would someone kindly take pity on me and explain why we're talking about VC1 vs mpeg2 for HD players? What the heck happened to h.264?
Arrogance and royalties. In the BD and HD DVD spec, all players MUST support Mpeg2, VC1 and Mpeg4. After that they can support whatever. VC1 is Microsoft's codec. Read up on mpeg-la to see how the royalties work but basically Sony get the biggest chunk in royalties when Mpeg2 is used by studios. Putting that aside, Sony has gone of record repeatedly about how Mpeg2 is the best format for High Def and they believe in it all the way. It would be quite the change for them to not only backtrack but then have to go infront of MS and ask them for help in implementing VC1.
VC1 is approximately 2x + more effeceint than mpeg2 which is requires much higher rates to display the same picture as VC1 with it's much lower raters.
The longer the movies, the more space it needs and using Mpeg2, 25GB is not enough, thus the quality suffers. 50GB would be fine because now you don't have to lower the rate on mpeg2 and it can be shown in maximum quality but it's still using 2x more space than if VC1 was being used which negates the 50gb space advantage for movies. 50GB discs are no where in sight and have strong rumors of production delays.
The current crop of Sony releases are not as good as HD DVD because they're running out of space on 25gb discs using Mpeg2. Sony refuses to work with MS to try and implement VC1 and keep saying they believe in Mpeg2 over and over. The could go Mpeg4 to preserve their arrogance. The problem with Mpeg4 is that for high resolution content, it's really no better than Mpeg2. Mpeg4's advantage comes when the res. is kept down. All Blu Ray titles currently goto Sony for mastering so it'll be interesting if they actually use VC1 for other studios at some point.
In summary:
A movie that takes us 20GB using VC1 will require 40GB using Mpeg2 to display the same picutre. Lowering the rate on Mpeg2 causes artifacts, soft picture, noise and macroblocking.
To produce a better picture, Sony varies the rates depending on the scene and how much they can get away with using a lower rate to produce an acceptable picture.