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raygun on 27 July 2010
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Ssenkahdavic said:
raygun said:
disolitude said:
raygun said:

Why would they stretch a 1920x540 image to 1280x 720??? Wouldn't they just double the vertical to 1920 x 1080? It would be easier, and what would be the point of generating a 1920 hrz rez frame knowing it's going to be reduced to 1280? This format would never be used, there is already a 720 3d format! 

To me what they are doing is sort of interlacing, one frame holds 2 1080x540 frames, they are stretched to 1920x1080, In effect your getting 1920x1080 left and right frames updated every 1/60 sec. The frames are subsampled to 540 vertical, and then stretched to 1080, but at 60hz rate per stereo frame, it's an averaging  interlacing, or at least that's what i'd call it.

lol. You are much more accurate with resolution definitions than me.

I believe 1080i per eye resolution is what you have in mind and its absolutely correct.

I tend to keep it simple and deal with 480p, 720p, and 1080p when I talk. 1080i is roughly the same amount of pixels as 720p and visual quality of both to the human eye is about the same... hence I don't distinguish the two.

But you are right...1080i not 720p. My bad.

Actually....1080i doesn't equal 720p, pixel wise. Maybe close if your just looking at one interlaced frame, but with 2 frames, 1080i is 1920x1080 pixels. Each interlace frame is 1920x540, but they are different interlaced slices of the total 1920x1080 frame. 720p is just 1280x720 pixels.

But, I don't think we can say that the "1920x1080p @ 59.94/60Hz (Top-and-Bottom) mode is interlaced, wouldn't they call it such? They are averaging every 2 vertical lines in a1920x1080 frame (subsampling) to end up with frames that are 1920x540. How can they call this a 1080p mode, I wonder? May be it's cross eye interlacing, the left eye gets the even lines, the right eye the odd lines? Seems I remember this being done in the past. 

Anyway, I would be totally content with a 1080p game running at 30hz, or better yet at 1080i at 60hz. 30 hz is what most console games run at anyway, and have trouble even getting that. Sure there's a few 60hz exceptions, StardustHD, WipeoutHD. But WipeoutHD, the sneaky bastards, uses 'variable horizontal resoulution', 1280 to 1920, and it still tears every now and then. 

Getting back to the OP, I personally am ready for a new TV, I like 3d, and will be buying one. It's either a panasonic vt20 or the new Vizio 480hz lcd's, depending on the reviews. A 60" laser or dlp is just too big for my apt., and I just saw the 3d adapter for samsung 3d dlp's listed at $300, without glasses. And i'm one of those people that notice the dlp rainbows.

You are confusing Hertz (Cycles per second) with FPS (frames per second)  While sometimes they are interchangable, for the most part they are not.  One is how many times your screen "redraws itself" per second (hz) and the other is how many different Frames are drawn Per second.  When they are equal (or FPS > Hz) a much smoother picture is born.

 

And for top/bottom (from page 7 on the 3D HDMI white sheet)

"For Top-and-Bottom, the original full left and right pictures are sub-sampled to half

resolution on the vertical axis. Sub-sampled pictures are arranged in Top-and-Bottom

layout. See Figure 8-6."

Ssenkahdavic, I mentioned the subsampling above," They are averaging every 2 vertical lines in a1920x1080 frame (subsampling) to end up with frames that are 1920x540" My point is how can they call this a 1080p format, when it's actually only 540p???? Do they just double the verticle lines at the tv to make it 1080p, or are they some how interlacing to get back up to 1080p? Just doubling the 540 to get back to 1080, then calling it 1080, is...lame.

I wasn't confusing the two, they are the same spec. applied to different things. 60hz refresh means 60 frames drawn per second. If a monitors refresh rate is 60hz, it's entire screen is redrawn 60 times a second. If a game runs at 320fps, and you have it hooked up to a 60hz monitor, your still only going to see 60 fps. I meant that if the maximum a tv could show was 1080p at 30hz, which is 30 1080 frames per second. That would be more than enough for 95 % of the games on consoles, that struggle to do even 720 at 30fps. 

Just read up on the 480hz refresh backlight trickery of those new Vizios coming next month, i'll just have to wait until the reviews come in.