What does Upscaling Really Do? - AVS Forum
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post #1 of 5 Old 07-23-2007, 01:25 PM - Thread Starter
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Not sure which forum this is best answered on, but
I just bought a new Epson 1080p Home Cinema Projector. My plan is to connect my Xbox 360 to it via a Denon receiver that UPSCALES all signals to 1080p. I currently only have Component Cables on the Xbox and know that it does not support 1080p on HD-DVDs due to copyright issues. My question is if I connect the Xbox to the Denon via component cables and my HD-DVDs gets upscaled to 1080p, will the picture quality be the same as if I connected to the Denon via an VGA/DVI cable. Or is something 'lost' in the upscaling process? Cant seem to find this answered anywhere, as I dont have a good technical understanding of what upconversion is. Any help would be appreciated, thanks!!
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post #2 of 5 Old 07-23-2007, 02:09 PM
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You have three things that are involved.

Deinterlacing - The taking of Interlaced and making is progressive. Examples: taking 480i to 480p or 1080i to 1080p

Transcoding - Taking a signal on say svideo connection or Component Video connection and sending it out the HDMI connection.

Scaling - Taking a souce outputting a resolution and making it a different resolution.


I'm going to bet that the deinterlacing and scaling of your new 1080p projector is going to beat every AVR out there at the same tasks.
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post #3 of 5 Old 07-23-2007, 07:23 PM - Thread Starter
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Hmm. I kind of follow but not completely. Maybe to put it another way, does it make a difference if I:
1 - Output an HD-DVD signal from my Xbox 360 at 1080i with a component cable, through an upscaling receiver, to an 1080p projector which then shows the picture at 1080p; or
2 - Output an HD-DVD signal from my Xbox 360 at 1080p with a DVI/VGA connection, through an upscaling receiver, to an 1080p projector which then shows the picture at 1080p

Just trying to understand generally I guess if taking a full HD picture to 1080i and then back to 1080p degrades quality vs. keeping it at 1080p the whole time....
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post #4 of 5 Old 07-24-2007, 02:07 AM
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No set rules. You generally have to try it all ways and see which is best. The current crop of Blu-ray and HD-DVD don't give you 1080p off the disc, they read as 1080i then deinterlace to 1080p anyways.

AVR's do not do these tasks well, or at least not near as well as the display.


Generally if the 1080p display is getting 1080i it will be identical to if it were getting 1080p.

1080i to 1080p does not get scaled, it gets deinterlaced. 1080i contains all the same video information conatined in 1080p.

720p, 1080i, and 1080p are all full HD.....
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post #5 of 5 Old 07-24-2007, 02:10 AM
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Quote:
Originally Posted by chicagofan View Post

Hmm. I kind of follow but not completely. Maybe to put it another way, does it make a difference if I:
1 - Output an HD-DVD signal from my Xbox 360 at 1080i with a component cable, through an upscaling receiver, to an 1080p projector which then shows the picture at 1080p; or
2 - Output an HD-DVD signal from my Xbox 360 at 1080p with a DVI/VGA connection, through an upscaling receiver, to an 1080p projector which then shows the picture at 1080p

At worst, the effect of "upscaling" to HDMI is putting a lower resolution video source on a higher resolution display, and adding extra artifacts in the process because of a poor quality implementation.

At best, the effect of "upscaling" is displaying a lower resolution source on a higher resolution display while, using special processing, filling-in some of the missing resolution (information) to improve the apparent quality of the lower resolution source video when it is displayed on the higher resolution display.

You hope for the later, but sometimes you get something more like the former.

For your situation, I do not think option 2 will work. Are you saying you want to put a "D-sub -> DVI" adapter on the VGA 360 output, and then put an HDMI adapter on the DVI connector in order to move the output to your HDMI receiver? I can't imagine how else you get 1080P from the VGA (D-sub) output to your HDMI/component receiver. Also, you mention VGA/DVI and this also leads me to ask that question.

If that is your plan, the problem is there are different kinds of DVI. There is DVI Digital and DVI Analog. A D-sub to DVI adapter makes a DVI Analog signal. This is not compatible with HDMI, at all. You can't get there from here.

If that was not your plan, how do you propose to get 1080P from a non-elite 360 into your receiver in your option 2, above?

Regardless, however, you will be fine with option 1. Well, in all likelihood you will be fine. Converting from 1080i over component to 1080P over HDMI should not be easy to substantially screw up for a competent transcoding/upscaling HDMI receiver. You should get pretty good results from Option 1, in other words.

Good luck!

Experience is a hard teacher because she gives the test first, the lesson afterwards.
-Vernon Sanders Law
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