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What's better - DVI-I to RGB or component thru transcoder to RBG?

1251 Views 29 Replies 13 Participants Last post by  Lifter
Sorry, guys. I've tried searching out this particular answer to no avail, so I'm just going to post the question. What should yield a better picture, DVI-I or component when the end result is RGBHV (Sony 1251, btw)? I've gathered that with a DVI-I output, you can get a simple adapter ($10 at Frye's) to go from DVI to VGA, and then just use a breakout cable into the PJ. If you go the component route, you've got to use a transcoder, and unless you spend about $800 or more, you're going to suffer some PQ issues...crushed blacks being the most prominent one mentioned.


So, will a DVI-I/adapter/breakout cable give as good a picture as component/mp5/bnc cables? If not, will it be better than the cheap transcoders (200-400) or the really cheap transcoders (70ish)? Where would it fall, roughly? I'm asking because I've done nothing yet. I'm on the waiting list for an 811 HD receiver from Dish ($99 upgrade for me since I'm a current customer...but that's a lease), but that DOES NOT have DVI-I, just DVI-D. Their 921 PVR HD receiver DOES have DVI-I, but it does cost a grand, and I don't think there's any wiggle room in that.


As far as DVD players, I think I could get either the Momitsu V880 or the Bravo D1 as both have the DVI-I output (is there a clear-cut winner between the two for CRT users?). Lastly, since I've only got a 1251, which resolution would be best? I believe it can handle either 720p or 1080i, but it can't resolve either fully? Is there a concensus on which looks best for CRTs that can't quite resolve either fully?


Thanks for any input.


Steve
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Steve, We are going to try that comparison at a group showing of Mike's new MP5 & his component modded Momitsu. We will also be using the MP5 to transcode a JVC digital tape deck & Motorola 5100 HDTV STB. Mike said he could not get the RGB out from DVI-I so he will have to figure what button needs pushed to retrieve the RGB signal before the meeting(hopefully in early FEB.) MP has a mod for the component out from Momitsu so the component out thru MP5 will a great chance to put out the best picture. I'm also eager to see this hot rod component Mom/MP5 vs the Mom in DVI-I/adapter/breakout cable/direct to PJ w/o needing transcoding, it will be enlightening!
I would guess that DVI-I to RGB would be better, since the DVI adapter is just passing through an analog RGB signal. Transcoding YPbPr will involve some signal degradation, and you also have to deal with tri-level sync being passed by cheap transcoders rather than being converted to bi-level sync. Of course I haven't tried either yet, as I'm waiting for my cheap transcoder to arrive, which I will sell as soon as my Dish service is installed. ;) FWIW, Dish still has the 6000u listed as available on their website, which has hi-def analog RGB output.
I bet Mikes Transcoder will look better. It looked much better here comparing the DTC-100 RGB out / JVC 30K deck component out. Using the 169Time Firewire mod feeding the DTC-100 to the JVC. Mikes Transcoder is amazing!
Thanks for the replies. Kemper, I'm glad to hear that you'll be doing that type of comparison. It will hopefully be very informational.


Squinty, that's what I was thinking as well. The problem with the 6000u and other HD receivers that output RGV via a VGA-type output, from what I've read, is that the HD signal is inherently component, so even the 6000u is transcoding down to VGA, just internally. I can't imagine the internal "transcoder" in the 6000u or the Samsung T150, et cetera, is all that great, which will probably lead to some PQ issues.


JRichards, thanks for your input. I know you've been very, very impressed with MP's transcoder, but I'm still very curious if the DVI-I is a cleaner output than those receivers that have a VGA output. I'm not sure (Mike would probably know, along with others) if the DVI-I RGB signal goes through a similar transcoding (i.e., starts component and ends up something else) that all the VGA-type outputs go through.


My guess is that Mike's will probably look better simply because he's going for the cleanest, most unmolested picture possible. I'm also thinking, though, that the DVI-I will be, perhaps, somewhere just below the MP-5 and well above the
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Quote:
Originally posted by S. Stogel
Squinty, that's what I was thinking as well. The problem with the 6000u and other HD receivers that output RGV via a VGA-type output, from what I've read, is that the HD signal is inherently component, so even the 6000u is transcoding down to VGA, just internally. I can't imagine the internal "transcoder" in the 6000u or the Samsung T150, et cetera, is all that great, which will probably lead to some PQ issues.


JRichards, thanks for your input. I know you've been very, very impressed with MP's transcoder, but I'm still very curious if the DVI-I is a cleaner output than those receivers that have a VGA output. I'm not sure (Mike would probably know, along with others) if the DVI-I RGB signal goes through a similar transcoding (i.e., starts component and ends up something else) that all the VGA-type outputs go through.
In a STB, the internal "transcoding to VGA" (really a colorspace conversion from YUV to RGB) could occur in the highly optimized MPEG decoding stage, so that the issues with analog signal conversion (e.g. electrical signal modification) that are present in external transcoders would be obviated. In that case, the differences in HD-15 (VGA connector) RGB output and DVI-I RGB output would come down to the quality of the DACs driving them and the decoding process on the STB. What I'm trying to say is that you shouldn't ask, "Is DVI-I RGB output better than HD-15 RGB output?" but rather, "Does STB A have higher quality software and hardware components than STB B?"


-Bob
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Thanks, Bob. Now I guess my main question is DVI-I compared to MP5.


Steve
I have a cheaper Sigma 8500 player that doesn't have DVD-I. It's like the Momitsu but lacks the DVD-I so a component transcoder is needed.


I know I would rather go the DVD-I to RGBVH route and maybe I'll buy another player and try that.


However, the cheap transcoder ($69.99 from ebay) seems to be doing very well. I know in theory there's a lot of reasons not to want to do the color space conversion but it's possible that these transcoders have enough bandwith that the conversion doesn't affect the quality of the signal.
Quote:
Originally posted by Brian Hampton
I have a cheaper Sigma 8500 player that doesn't have DVD-I. It's like the Momitsu but lacks the DVD-I so a component transcoder is needed.


I know I would rather go the DVD-I to RGBVH route and maybe I'll buy another player and try that.


However, the cheap transcoder ($69.99 from ebay) seems to be doing very well. I know in theory there's a lot of reasons not to want to do the color space conversion but it's possible that these transcoders have enough bandwith that the conversion doesn't affect the quality of the signal.
I compared Mikes MP-5 with the Extron Transcoder and the difference is LARGE! The colors and blacks are alot clearer and look much more 3D.

When I first saw mikes unit hooked up it was like a layer of haze was removed from the picture. I could never see all the shades of blacks and the bright colors with the Extron.


I tried the cheap transcoders before I purchased the extron and didn't like them at all.


As soon as mike has them ready I will have one in my setup.


Any one need an Extron Transcoder?
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I agree with Jeff Richards, after seeing Mikes MP5 on my 9501LC I purchased for Jeff (thanks Jeff) the picture just came to life. Everything that Jeff saw is what i saw and WoW was there a lot more to see in that picture. I am also waiting on Mikes MP5 it will definitely be in my system.


Jeff : Have you added any new toys to your collection.
I thought the analog signal out the DVI-I was already RGBHV. Thus, no transcoding required.
Thanks again for the input, guys. WanMan, yes it is already RGBHV, so you just need an adapter (to VGA) and a breakout cable. But I wasn't sure how the analog signal got to be analog. It was my understanding that when it comes to HDTV, for example, that it is inherently component and that those HD receivers with a VGA (RGBHV) output actually had to transcode the signal internally. Squinty, however, pointed out that it doesn't necessarily have to occur as a "transcoding" but CAN happen in the digital domain (if I understood him, which I'm sure I didn't). Thus, it's possible that the VGA out of a STB could be a much better signal than, say, component transcoded (via external transcoder) to RGBHV.


So, yes, it already is RGBHV, but my question was whether or not that RGBHV signal would be better than a good (MP-5) transcoder. I'm starting to think that it probably is not, but that it may be close enough for all but the most finicky of critics (no offense, Jeff ;)...seems the Extron is better than most, but not nearly as good as the MP-5 and some people can tell a significant difference).


Steve
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Do you have the extron to compare at this viewing? If not I can provide mine. That way the MP-5 Transcoder can be compaired with another transcoder also.
Anything under a grand will be a bargain. My guess is somewhere between $700 and a grand.
I will need a Component to RGB transcoder, but $700 is just too much money for me. What is my next best option in the $300 proce range? I understand Mike Parker's work is great, but I just can't afford it.


Thanks!


EJ
I think the price on the two-input MP-5 is going to be $800, IIRC, and I also thought I may have read something about it debuting at $700 (?). That could be a mistake or maybe the price of the single-input model, but I thought in the "Transcoder on it's way" thread that that's what I read. Guess I'll know more what to do once they have the meet in February.


Steve


P.S. From what I've gathered, $300 may be no-man's land when it comes to transcoders. I could be wrong, but I think the little $70 ones do almost as good a job as the $200-300 ones (and I very well could be wrong). Also, there seems to be a price gap between 300 and 700+, which is where the next group seems to reside. So perhaps DVI-I with adapters or spend $70 on a cheap one and save up for the MP-5? If I don't go all DVI-I, I'll like likely go for the MP-5. If I do DVI-I, I'll likely get a $70 one for gaming or something other than HDTV and DVD. My $0.02.
The new Key Digital is fine for consumer grade displays, but not for high quality FP CRTs. MP's product will fill a void, it will be an interstitial filler. It is not designed to be a better mousetrap for the same amount of money. It is designed to exterminate the rats, not just to keep them under control. There is simply at this point no alternative that will not significantly degrade picture quality.
Most of the transcoders out there affect color decoding. Use avia dvd to check color decoding. Almost all the decoders seem to affect green decoding by -25% which is a great no no. A pure RGBHV output without transcoder does not have this problem and signal is better than say from component to RGB, period. DVI-VGA is also excellent and should be the best connection if available to a CRT.
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