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Originally Posted by zalas
Now, when you said that the BS-i version was a ton better than the DVD version, I had thought you meant that the BS-i version was from some mysterious HD source. Even a bad rip of that would've captured at least some (albeit noisy) detail from the HD that wasn't in the DVD release. However, if it was from a SD upconvert, the bad rip would then probably look poorer than the DVD, due to the fact that the bad rip of the upconvert would be travelling through 2 lossy channels (BS-i, ripper), while the DVD would be travelling through only 1 lossy channel (DVD encode). If the original source were HD, the DVD would've traveled through two lossy channels (downconvert, DVD encode). Furthermore, if the original source were only SD, then of course BS-i would have a much better time fitting the same material onto a bitstream more than twice as wide (assuming 20Mbit stream for BS-i).
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I doubt there was actually a HD source, otherwise you would think that BD AIR would have used it instead of upconverting from a SD source, no?
You've pointed out why the BS-i broadcast looks better than DVD, and by the same argument, BD AIR should at the very least look just as good as the BS-i broadcast assuming that 1) they use the same source (which is very likely) and upconverted it correctly 2) BD has a higher bitrate and more bandwidth to work with. But the result is contrary according to reports, with BD AIR sitting somewhere inbetween the BS-i and DVD.
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The whole discussion seemed to have been focused on picture quality/storage size from the way it was going, so I did not realize you are now thinking of other problems with BluRay. I agree that there are problems with BluRay in terms of actual logistics, but that's not what we were arguing here. As BD is a digital format, a physical manufacturing process and/or authoring process should have little to nothing to do with the quality of the video stream, as long as the video stream is correctly etched onto the disc, bit by bit. Thus, the only reason AIR BD would look terrible would be in the video encoding chain, and thus it's either 1) the source, 2) the upconverter or 3) the MPEG2 encoder. The only part that actually is part of the BluRay spec would be the MPEG2 encoder. The rest has nothing to do with BluRay itself, and would've been the same had it been HD-DVD.
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I guess I should elaborate on the complaints towards BD AIR. While the aliasing artifacts is and can be attributed to upscaling, there are also instances where pixelisation is occuring in various high motion scenes. The most obvious of this is when during the opening scene where Mizusu is spinning around, the the DVD version pixelation was very obviously occuring for the whole of Mizusu's character while the BS-i version don't have this issue, so this shouldn't be a converting issue but rather a bitrate issue. When I was looking at BD AIR I specifically paid attention to this scene and the stream they were showing had pixelisation in it (though yes, not as bad as the DVD), while it may be just due to that stream being poorly encoded, it's not exactly encouraging when you supposedly have 40M/bits to throw at the process (actually they even showed the bitrate bar and it clocks at 40M/bits) and still have such simple compression artifacts.
Also don't forget that there's also the *decoding* chain where image degration can occur. Not all signal processors are made equal.