Originally Posted by Fudoh
no idea why I missed your last posting back in late august.
The thing the VP20/30/50 does wrong in Game Mode 1 is the following: on a 240p signal all 60 fields are to be displayed on the same height level. This is why a classic CRT TVs give you the typical scanlines.
What the VP20/30/50/50pro should do is this: it should take every of the 60 fields without moving it up/down compared to the previous field, double it to 480p by adding the same field ONE LINE down. and then scale to the output resolution. This would display single horizontal lines rock solid - just like on a CRT.
What the VP20/30/50/50pro DOES INSTEAD is this: it moves every 2nd field down one line before doubling and scaling it. (this is done to keep the original field order and position of the fields on 480i material). This makes the screen a bit shaky, giving what I described as the "bobbing" effect on my posts before.
The problem MIGHT be that the DVDO VPs can't tell a 240p signal from a 480i signal and thus can't decide wether to keep the fields on the same height level (for 240p) or adding an offset to every second field (for 480i material).
This could VERY EASILY be changed via a manual switch in the options though. Let's keep the fingers crossed that it gets added one day.
Sorry for the huge delay in replying. Been extremely busy lately.
I believe the VP50 does
keep every scanline on the same height with 240p sources in Game Mode 1. I tested this extensively by zooming in using the VP50, and then zooming in on my monitor, to get a total of roughly 8x zoom so I could see the "pixels" up close. It looked entirely like it was keeping every scanline at the same height.
I did another test. When a typical VCR displays a menu over a blue screen, such as the menu for programming the record timer, this is 240p output. However, when it displays the same OSD over playback video (such as the channel number), it is 480i. This can be observed on an ordinary CRT by displaying the TV's OSD on top of the VCR image, because the TV's OSD flickers or not based on the video mode of the TV, and the TV's OSD is a good test case because of the high-contrast text.
In the VP50 set to Game Mode 1, I observed vertical "vibration" when the VCR's text displayed over a video, but no vibration at all when the VCR was displaying text over a blue screen.
In fact, I discovered this by accident. When I use a VCR with the VP50 I use Game Mode 1 because the increased softness masks the artifacts inherent in the low-quality source. When Game Mode 1 is used on most sources (480i), there is vertical bobbing because there is no motion-adaptive deinterlacing. However, I noticed it looked completely still on the blue screen with text of a VCR. I hooked up the VCR to a CRT TV and sure enough, it was 240p.
I also compared the output of a PS1 game, played on a PS2 over component, through the VP50 with Game Mode 1, and through the XRGB-2+. The display was, in fact, a bit better with the VP50. (For S-video and composite, the XRGB-2+ was better.)
I'm very confident that the VP50 correctly handles 240p in Game Mode 1, and treats the scanlines in every field as being in the same vertical location. There was frame judder in S-video and composite, which I suspect has more to do with the source quality (NES, SNES, and N64 consoles) than the fact that the source is 240p. Both the Algolith Flea and the PDI Deluxe card also had trouble receiving these sources.
I still think the bobbing effect is just a deinterlacing artifact caused by the fact that the VP50 is using the diagonal interpolation algorithm to fill in the "empty" scanlines, and noise in the signal. The diagonal algorithm decides the angle of interpolation. I'm speculating that it uses "hard thresholds", so when certain pixels are certain brightnesses and/or colors and then one is just very slightly brighter the next field--something that could be caused by noise--the angle is different, and that causes the sparkly effect. If it were bobbing caused by alternating the heights of scanlines, it would be far more pronounced. Which is exactly what is observed when viewing a still image in a 480i signal in Game Mode 1.