HDMI to DVI worth it?



Quote:
Originally Posted by murray /forum/post/0


Well this is good news. Will it also fix any pending content down res that we all have heard about via component?

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Hi Murray,


Even in the initial releases of the firmware, most players connected via HDMI to DVI did not experience down rezzing problems. Nevertheless, although not the majority, a significant number of folks with HDMI to DVI connections (about 40% per an AV Sciences poll) did experience the problem. Since the initial releases Toshiba has issued several firmware releases, including the most recent v1.6, which addressed playability problems. So while there's no absolute guarantee that your display won't experience a compatibility problem, the probability is greatly reduced.

Quote:
Originally Posted by murray /forum/post/0


Will the HD DVD's look better because the digital signal is straight?

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It would appear that all Toshiba players connected via HDMI to DVI experience a colorspace problem where the player incorrectly sends PC RGB levels instead of studio video levels. This results in images that are too dark with a loss of shadow detail. This problem does not occur over the component video connection. I have found that by adjusting the picture settings (brightness and contrast) on the HD-XA2 that I can get the images via HDMI to DVI to look, to my untrained eye, as good as via component. (I have an HD-XA2 connected to an InFocus ScreenPlay 7205 projector via HDMI to DVI and component video.)


Nevertheless, knowledgeable forum members consider this an imperfect workaround and believe that image quality is still subtly compromised. It should also be pointed out that not all HD DVD players have convenient user adjustable picture controls such as the HD-XA2. Therefore, to resolve the lost shadow detail on HDMI to DVI requires adjusting the display's settings. Needless to say, this is a major inconvenience since other HD source devices connected to the display, such as cable or satellite boxes, will be thrown into miscalibration by adjusting the display. Obviously, the problem can be avoided when viewing HD DVDs if the owner chooses to use a component video connection. However, the problem can not be avoided if the user wishes to view an upconverted standard DVD which as you know requires a digital connection.


So in summary, no, with the current flaw in the colorspace processing, HD DVD may not look better via HDMI to DVI digital than via component.


Larry



Quote:
Originally Posted by erick granato /forum/post/0


I believe the colourspace issue was only found to occur in front projectors, if you have a rear projection, plasma, or lcd tv you would be ok with hdmi-dvi connection.

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Hi Erick,


I believe that you are mistaken.


What electronic principal would come into play that would make the player function differently between a front projector and a rear projector? For example, what is the difference between a front CRT projector and a rear projection CRT HDTV that would account for the difference in operation that you are suggesting? The mirror?


Larry



Quote:
Originally Posted by erick granato /forum/post/0


The difference is that most lower cost projecters are originally designed to be used with computer power points and display colour in rbg colourspace. The regular tv's display (accept?) colour in ycbcr colourspace which the Toshiba hddvd's use.

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Hi Erick,


Consistent with the title of this thread, in posting #5 , I was specifically discussing the problem that Toshiba players have when connected via HDMI to DVI.


Even more expensive projectors that are designed to accept studio video colorspace, rather than PC RGB colorspace, will still experience the wrong colorspace levels because the player is sending the wrong levels.


If your premise is correct that low cost projectors are designed for PC RGB levels, then your reasoning is reversed. In this case the inexpensive projector might actually be better able to deal with Toshiba's flaw since, when connected via HDMI to DVI, the players are erroneously sending the same levels that the inexpensive projectors are designed to accept.

Quote:
Originally Posted by erick granato /forum/post/0


When you use one of those converters, you do an external conversion from rgb to ycrcb colourspace.

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Yes, but in doing so the digital connection is converted to an analog connection, and it is questionable whether the upscaling would work on an analog connection. In other words, the players already have analog component video connections that correctly handle colorspace, yet they are incapable of supporting upscaling because they are not digital connections. While converting the players' HDMI output to analog component video might resolve the erroneous colorspace issue, the real problem is maintaining the ability to upconvert standard definition DVDs which requires a digital connection. By converting the player's digital connection to an analog connection is it not certain that upconverting would still work.


Larry



Quote:
Originally Posted by jmpage2 /forum/post/0


I thought someone recently reported that FW 2.2 fixed the color space problems for them on HDMI->DVI with an A1.

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Hi,


Can you provide a link to the posting?


I scanned this posting and concluded that the colorspace problems had not been resolved.

Toshiba: 1st gen FW 2.2 available- see first post for FW ISO


Here's an excerpt:

Quote:
Originally Posted by Clarence /forum/post/0


Can anyone who has upgraded a HD-A1 to v2.2 please try this same THX Optimizer test.

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Quote:
Originally Posted by cpcat /forum/post/0


I tried it with the exact same set (Sony GWIII) and unfortunately got the exact same result.


It appears that V2.2 is providing RGB at PC levels over DVI. This will result in a picture which is too dark. If the set can't be recalibrated to accept PC levels (which the GWIII can't) then the only option would be to revert to component connections.


The better option would be to provide video levels (compressed to 16-235). This was the situation with V1.2. At least then, calibration wouldn't be as much of a problem (although below black and above white are still not present).

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Larry



Quote:
Originally Posted by jkscherk /forum/post/0


Wow...reading this has me a bit confused. It sounds like when using the Toshiba HDDVD players, you'd be better off using the component connections v. the HDMI>DVI conversion method if your display has only DVI. Yes?

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Hi,


Yes, if all you're interested in is watching HD DVDs. However, if you want to use the upconverting capabilities then you have to use the HDMI to DVI connection. If you buy an HD-XA2 it permits you to adjust the picture settings to get a very satisfactory image without screwing up the calibration of other devices connected to your display. If your HD DVD player doesn't have picture adjustments, then you have to use the projector's adjustments. If your projector permits recalling multiple user settings, then this player problem might not be a major inconvenience. Otherwise, it will be very inconvenient.

Quote:
Originally Posted by jkscherk /forum/post/0


If I have a display (Sharp 12000MK2) and video processor(Lumagen VisionHDP) , both of which have DVI or component connections, that I'll be using with a Denon 3930 dvd player (HDMI or component) and HD cable box (DVI or component), would I be better off going all component, all DVI, or some combination of both?

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You don't indicate which HD DVD player you are considering. As I said, if you have an HD-XA2 there is a workaround to the HDMI to DVI colorspace issue. I'm not familiar with your projector, but if it has multiple picture settings that may be a reasonable workaround as well. Some folks with Lumagen scalers and first generation players reported that the Lumagen resolved the colorspace problems on the earlier firmware releases, but the more recent firmware releases resurfaced the colorspace issue again even with the use of a Lumagen. If you don't plan on using the HD DVD player to upscale standard DVDs then using the component video connections is a "solution".


Larry



Quote:
Originally Posted by erick granato /forum/post/0


Larry- I think you misunderstood. I have a Hitachi 51swx20b which only has a Dvi input. I have a HDMI>DVI adaptor cable and it works just fine. My tv only accepts ycrcb colour input which is the native output of the Toshiba HD-A1 from HDMI. The DVI input on the tv is, I believe, DVI-D which is ycbcr colourspace. The front projecters only accept rbg input which the Toshiba does not output over HDMI. I have v2.0 firmware, HDDVD's look great and standard upconverting DVD's also look great-with no colourspace issues. I know because I have a/b with a Denon dvd player over component and no change in colours or shadow that I can tell. I have also recently bought the HD VIdeo Essentials and all of the colours seem to be there.

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Hi Eric,


I'm sincerely glad to hear that you are not experiencing problems.


Nevertheless, you are mistaken in a couple of areas.


First, the Toshiba player are SUPPOSED to output studio video levels. However, they have a defect that when connected via HDMI to DVI, they incorrectly output PC RGB.


Second, as I mentioned previously, not all front projectors are designed to accept PC RGB. In fact, I believe most modern projectors are designed to accept studio video since that is what most commercial content is authored in. I have an InFocus ScreenPlay 7205 DLP front projector, and although it is not a "high-end" projector, it is designed to accept studio video. This is the norm, not the exception.


With regard to your comment about all the colors seem to be there, despite its name, the colorspace issue problem has nothing to do with colors. It has to do with incorrectly setting the grayscale levels. When a display that is designed to accept studio video levels receives PC RGB levels, the black levels are incorrect. This problem manifests itself as a loss of shadow detail, i.e., the image is too dark and dark details are "crushed" against a dark background.


I don't pretend to be an expert, but my guess is that the reason your HDTV is not experiencing problems is because, contrary to your statement, its DVI input is designed to accept digital RGB. Here are the specs on your HDTV. As you can see it doesn't state that the DVI input accepts ycrcb, but rather RGB.

51SWX20B


Larry