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Discussion Starter · #1 ·
Darren,


Just curious: did you see any scaling artifacts when you fed the Sony straight into the G11 display?


Got a 9015 D-ILA and when we recently tried a Skyworth DVD-1050p PS player outputting RGB (progressive scan) in its computer 1 input (SVGA1), doing the PAL format thing, imaging looked exceptionally good, although not as good as when I use a HT-PC and the 9015 set to do 1365x1024 (SXVGA3). Btw, I was told the 1050p machine is chroma bug free (among other things) when outputting RGB signals. I believe is true...


-THTS
 

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Hi Frank,

I did not notice a lot of artifacts. Actually, as I mentioned in the previous post, the video image appeared to be much cleaner. This is what threw me the curve. I was always under the impression that the de-interlacing provided by the CI would make for a better image. As for the HTPC, I do not have one. I really dont have the knowledge for a HTPC. That is why I have elected to order the Rock+. With that said, that made me think. Maybe the reason is that with the interlaced image through the CI without the option of changing the refresh rates from 60 to 72 is why the progressive signal straight to the pj. looks better. Any comments?
 

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I am having similar experiences with my G-15 and my Quadscan Elite. The Quadscan image is noticeably inferior to the image straight into the video input of the G-15. I have concluded that it is a defect with the Quadscan, as a vidoe processor should improve the image, or at least not make it worse. I wonder if your CI also has a problem.
 

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Discussion Starter · #4 ·
Darren, smitty,


I think the difference is that with scalers extra processing is taking place while direct feed by progressive scan (standalone players and HT-PCs) does away with it, resulting in cleaner imaging. I've noticed this to be the case when I use my CI scaler/Sony DVP-S7000 combo, which the HT-PC surpass with overall visual quality.

I believe that the Rock machine does its scaling like a PC, so results should be similar to using them...


-THTS
 

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Here is the delima that I would appreciate someone educating me on what is going on or what have I done wrong.

My current set up is a G11U set to sxga3-CI set to 1360x1024 with 4:3 output-Sony 9000ES DVD Player set to 16x9 and interlaced output.


This morning, I decided to play around a little. I have always used the 9000ES with the CI. I just tried bypassing the CI and connecting direct to the pj. via Y-Pb-Pr and setting the Sony to Progressive output with the proj @ 480p. Unless I didnt sleep enough last night, I would have to say that the image is substantialy better. Why? I thought the scaler would not only scale the image but also enhance the image. The direct method seems to be better in all aspects of video quality. Sharpness, Color, Contrast,etc. appears to be much improved. This is the first time I have ever used the progressive output as the CI will only accept interlaced. I am lost now!!!


What brought all this on was I disconnected the Sony from the CI because I just purchased the Denon DVD3300 and was connecting it. (A whole different Post) Am I seeing things? Could someone explain why this is? Is this a flaw in the CI? Is there a problem with my setup? Or is it that the progressive output is that much better?


The CI is a temporary thing as I have a Rock+ on order but has not arrived as of yet. I purchased the Denon because of the Chroma bug issue with the Sony. But if what I am seeing is the benifit of Progressive scan vs. Interlaced I will probably go back to the Sony input to the Rock+ with progressive scan. While on the subject of Chroma bug, could someone explain exactly what this is? I thought I knew, but apparantly its not what I thought it was. I will say that the Denon appears to have better color saturation than the Sony. That is, with the sony set to interlaced.


Please educate me.



[This message has been edited by DarrenW (edited 07-22-2001).]
 

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Smitty, Frank,

Maybe what we are seeing is a combo of several factors.

1) Improper refresh rate which causes these artifacts to be more prominent.

2) Poor De-interlacing

3) Digital to Analog conversion


I sure hope my Rock+ eliminates these problems. I dont think I can view my DVD's anymore thru the CI. And the inability to scale is driving me nuts.
 

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I have a quadscan elite and a G11U and i notice a much improved picture over the direct input to the G11U. The picture is more film like the colors are great and no motion artifacts.
 

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If I'm reading this correct, you're saying that when you DVD player is sending out a progressive signal, the end result looks better. That seems to make perfect sense.


In general, anytime the de-interlacing is done in the analog domain (this is the case for a scaler that is fed an interlaced signal), it will be inferior to de-interlacing done in the digital domain.


DVDs are unique in that they are authored in a manner that makes generating an interlaced output very simple; yet, all of the information is there to produce a progressive signal as well. Through a relatively straight-forward algorithm, a perfect 480p signal is produced with no interpolation, no frame-to-frame analysis, no guessing on the part of the software. (OK, notwithstanding the video flags issues). Only after this step, does a progressive DVD player create the output signals through its Digital to Analog Converters.


This is not to discredit all of the work that a good Scaler does to improve an interlaced signal, when that is all that is available. In that case, very sophisticated and truly artistic algorithms are used to detect and generate, using frame-to-frame analysis, a new progressive signal.




------------------

DVI/HDCP makes your HDTV not ready
 

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Basically what you are seeing is a difference in the

performance of the various components.


For all of the above combinations - the set of processes

is the the same.


First the interlaced signal has to be de-interlaced into a

progressive signal at the DVD's native resolution of 480p.


Secondly, the 480p signal has to be scaled to the resolution

of the D-ILA.


When you use the progressive scan DVD player - the player

is doing the de-interlace - and the D-ILA's internal

scaler is doing the resolution conversion.


When you use the CI - feeding it an interlaced signal, and

having it output a native D-ILA resolution - the CI is

doing both the de-interlace and the resolution conversion.

[ When the D-ILA receives a native resolution signal - the

internal scaler is effectively bypassed. ]


Therefore, based on your observations - we can conclude

that either the DVD player is doing a better job of

de-interlacing the signal than the CI, and/or the D-ILA's

internal scaler is doing a better job of scaling to the

D-ILA resolution. One or the other or both.


Greg
 
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