Originally Posted by zel
PReP needs the original fields to work. If your source scales the image, PReP can not reconstruct the original interlaced picture for deinterlacing.
Feed it 480p for SD source, 1080p for HD source. 720p does not make sense with PReP as there is no 720i to reconstruct.
Originally Posted by MichaelJHuman
PReP DOES correct 720p from my 360 playing the HQV test disc. Test it yourself if you don't believe me. Sorry if I sound snippy
You may be on the right track though. It's possible it can't correct 1080p for the exact reason you state. But I don't see how your theory is 100% correct for the above reason.
Here's my take on this whole mess:
Natively, "most" DVDs are progressive 23.976 fps with pulldown flags enabled so that the content can be played back at either 60i or 60p. In the case of 60i, you get a telecine pattern on playback that basically looks like a repeated pattern of 3 progressive frames and 2 interlaced frames. In the case of 60p, given a steady cadence and proper flags, you get a pattern of 3 repeated frames followed by 2 repeated frames and start over.
While I haven't tested many upconverting DVD players, I have tested a good number of external live source VPs and STBs which can play back 23.976 video files. The best implementations that I have witnessed take the original progressive 480 23.976 fps, upconvert that to the desired resolution at 23.976, and then
apply a telecine to bring it to either 60i or 60p. From what I have read of most DVD players though, they don't usually do this.
If I understand correctly, it seems that most players take the 480 24p and first apply the telecine to bring the content to 480 60i. The DVD player will then upconvert that image to 1080 60i (unfortunately scaling fields instead of frames in the process). If you want 1080p out, the player will then deinterlace that material to 1080 60p. (This seems awfully dumb, but maybe there is a limitation to the DVD spec and/or the players themselves that makes this the de facto way of handling things?) Depending on the implementation of the deinterlace process here, you could wind up with two very different results: a) the good implementation, where the player effectively applies an inverse telecine on the 1080 60i material bringing it back down to 1080 24p as best as possible, and then enabling pulldown on this to output it at 1080 60p; or b) the poor implementation, where the player simply separates the fields on the 1080 60i material to bring it to 1080 60p. The problem with "b" is that some frames will look OK while others will look terrible.
I imagine that the XBox 360 uses the "b" implementation, because it truly is one of the worst DVD players I have ever used (I'm talking PS2v1 bad IMHO), and this seems to replicate what I see from it when upscaling. Also, with implementation "a", even though the image is 1080 60p, it wouldn't be that difficult to either create or reconstruct the original fields or frames of the source due a mostly intact 3:2 pattern. But with implementation "b", reconstructing the original fields or frames at a steady cadence would be very difficult for most gear. This could then explain why the 2010 can't improve on the signal at 1080p in from the 360 because the original fields are long gone, like zel
For 720p in, my guess is that PReP is indeed having a positive effect because there is some required processing involved (I am assuming that you are connecting to your TV at 1080p through the receiver of course; though I don't seem to recall you mentioning exactly what resolution you went from the 360@720p to the 3900 to the TV; if you went from 360@720p to the 3900@720p to the TV, then I would agree with zel
that any perceptible improvements wouldn't make much sense unless they were coming from the TV itself). Most likely, PReP is upscaling the 720 60p to 1080 60i first and then deinterlacing to 1080 60p, which probably does look better than direct 1080 60p out from the 360 (due to the 360's terrible scaler not scaling the image as much). I would imagine that 480i or 480p would still be the better choice though if you had to use the 360 as a DVD player.
Originally Posted by kriktsemaj99
The ABT2010 is shown in the service manual (block diagram on page 105). Yamaha service manuals have full schematics and always seem to be accurate. It doesn't mean they are using all the features of the 2010 though (we know some things are reserved for the Z7, to encourage people to put down some extra cash).