Which one is the best to use, looking only at the qaulity?

[AirTimeDMC-12]

Which if the these new programs is the best to use, if only looking at the quality. And how do they work exactly? I haven heard the only recompression a part of the movie, not the whole movie. Does that mean you can watch a movie and suddenly a part starts of less quality?

[mpucoder]

Please, no more violations of rule #12 ("don't ask what's best") These always blow up.