Digital Upconversion???

[jocko_nc]

Question: What are the real results of "digital upconversion" in a video source, for instance, in a DVD player? What do these devices actually do?

I have a problem with the whole concept. I work in controls and am well versed in the concepts of resolution, accuracy, and repeatability. Realisticaly, one cannot upconvert from a lower resolution source to a higher resolution one. While there may be more data, the information contained is still the same as the original. That is a basic fact. Do the processors in these these devices make assumptions as to what the original source was trying to represent, perhaps sharpness, curve fitting, and textures, to try to refine the images? How do they "know" what was originally there?

I do not understand what this is all about.

Thanks in advance.

jocko

[edtyct]

Question: What are the real results of "digital upconversion" in a video source, for instance, in a DVD player? What do these devices actually do?

I have a problem with the whole concept. I work in controls and am well versed in the concepts of resolution, accuracy, and repeatability. Realisticaly, one cannot upconvert from a lower resolution source to a higher resolution one. While there may be more data, the information contained is still the same as the original. That is a basic fact. Do the processors in these these devices make assumptions as to what the original source was trying to represent, perhaps sharpness, curve fitting, and textures, to try to refine the images? How do they "know" what was originally there?

I do not understand what this is all about.

Thanks in advance.

jocko

Essentially an upconverting DVD player does what a fixed-pixel microdisplay does to a DVD signal--scale it digitally to match a particular resolution. Although, as you say, you can't squeeze blood from a stone, processing in these devices is capable of extrapolating, and otherwise cajoling, from the 420p signal a genuinely improved picture, though not always. Sometimes the base signal is just too noisy/badly resolved for the data to stand much processing, or the processing itself is substandard. In the HDMI/DVI-enabled DVD player's case, relieving the monitor or projector from scaling and converting (of the D/A and A/D type) can keep lines in the picture from blurring and colors from distorting. Success in this case is not just intellectual or theoretical; it is measurable. Tests show that a DVD player's upconverted signal can exceed the fine pitch of its 480p signal (offhand, Widescreen Review's report on the Sony DVP-NS975V and Ultimate AV's and Home Theater's reports on the Bravo D2 come to mind as examples). So, even though a DVD player's digital upconversion of 480p to 720p (or, in some cases, custom upconversion to 768 or 788p) is not true high definition, it can result in a perceptible increase in sharpness and fidelity. CRT displays running at 1080i aren't as good a target for this scaling as LCDs, DLPs, or plasmas since they cannot eliminate analog conversion along the signal path, even with an HDMI or a DVI input.

Ed

[jocko_nc]

o.k. Thats kind of what I figured. Thanks for the info.

I just bought a Toshiba 52 inch DLP / HD. (Nice set, but that is another matter...) I am currently running a progressive scan DVD player w/o upconverting. Toshiba SD-K710, circa 2002. Component video cable to HD1 input.

From the specs I could find, the video DAC seemed to be comparable with the current offering of 150 and below DVD players. It did not seem horribly out-of-date. The more expensive ones offer more bits and higher clock speed, and the upconverting.

Thus. Is it worth my while to buy a $250.00-ish DVD player with DVI / HDMI and the upconverting? Will I see such a difference? When does the true HD DVD's come out? How much content will be available? Should I wait?

Thanks in advance.

jocko

[Mr Peabody]

Do you have a link to that Widescreen article? I'd be interested in seeing if they mention anything about the fact that the DVD players that upscale can't or don't upscale copy protected DVD's which I would suspect is the majority of DVD's on the market. I wonder what DVD they used for their test. I'd also like to see if they mention that so far you can only get 2.0 digital audio from any of the DVD players. The whole upscale and HDMI is a consumer fraud in my book. I have an email from Sony confirming the ns975v won't upscale copy protected DVD's and it states it in the LG owner manual. Is the blame on the movie industry or the electronics companies for selling a feature they know is useless or is it HDMI LLC who put out and marketed a cable that has been made nothing more than a digital version of a RF connector due to the software and hardware limitations? Either way the consumer is the victim.

[edtyct]

Mr Peabody, we went through this before. In general, these players won't upconvert through their component (analog outputs), and the players that can (only one, the Bravo, comes to mind) can't do so with copyprotected disks, which happen to be the overwhelming majority. Through their digital outputs, protected via HDCP, they can certainly upconvert; the empirical evidence is indisputable. However, both source and target units must implement HDCP for the HDMI/DVI connection to work. Why this feature would be so hard to swallow is beyond me. Just about every HD-capable microdisplay on the market upconverts DVDs as well, even if only to match the monitor's native resolution. The upconverting digital DVD player's advantage over the monitor, in many cases, is only that it can simplify the signal. The disadvantage is that the player and/or monitor might read this signal as actual HD and incorrigibly include the wrong color space for it, as the Sony does (the Widescreen Review article documents this flaw). The WSR review on the web is restricted to subscribers only, but it was in the print issue before last. Home Theater and Ultimate AV also have reviewed upconverting players within the last volume year, and The Perfect Vision has made favorable comments on the phenomenon as a whole (go to the web pages for these magazines and search under Bravo D1 or D2, Samsung, etc.; sometimes the articles are available for viewing in their totality). The highly technical and informative Secrets of Home Theater site has tested a number of the players--including the Denons, Samsungs, and Sony. Google it and check out these comparative, detailed reports for yourself.

As far as audio is concerned, HDMI easily has enough bandwidth for a 5.1 or 7.1 DD or DTS signal stream, and much more. Anyone with a front panel readout of activated channels on his/her on an HDMI receiver or pre/pro should be able to confirm for you that HDMI is not confined to 2.0. I should add, however, that one major problem with HDMI at this point is that it's too new to be on many pre/pros or receivers, thereby limiting its utility for audio. What good does HDMI audio do going from a DVD player to a TV that has only two channels? Its convenience and capacity will be wasted until the industry catches up with it.

Ed

[jocko_nc]

I think I stick w/ what I got...

jocko

[Mr Peabody]

My question is to you, do, YOU, have HDMI? In fact both my TV's have HDMI. I bought a Sony 30" wide screen with the ns975v because of the crap the sales person said about it. The ns975v died after about 30 days and I got my money back and now I am trying the LG. I am not bothering with HDMI on my Toshiba DLP. No one denies the bandwidth of the HDMI cable. You didn't pay attention to what I said. When I began hearing some of the things about HDMI I went straight to the source, the manufacturer. NO current dvd player on the market puts out more than 2.0 audio. Sony admitted in an email to me that they do not upscale from HDMI output on copy protected dvd's. LG states that fact in their owners manual. Another thing is no one will be able to tell me HDMI sends a 5.1 signal because so far only a couple very expensive receivers have the input and it's useless at this point for 5.1 because like I stated the dvd players aren't sending 5.1 yet, if ever. I know of a guy who bought the Denon 1910 and tested the HDMI against the component out through a $7,500.00 Sim projector and he is using the component today because he said it was better than the HDMI. So either the writers of the articles you read have dvd's with no copy guard or I have to question their integrity. HDMI has the potential of doing what it says but at this point it does not. It is limited by the ability of the dvd players and movie companies. You should quit pushing this HDMI without knowing the facts because you are helping the corporations perpetuate their deception.

[edtyct]

I'll leave you happily as the reigning expert on HDMI audio. I know what it is capable of doing; whether it actually performs up to its capability is something that I can't verify. I use a HDMI-DVI cable from a Sony 975S (my second one; the first lasted a month). I set the Sony at 720p for my 788p display. It looks stunning. I have heard reports that many people prefer their component signal to HDMI or DVI, regardless of the monitor's price. I have mentioned some of the possible reasons in passing. Others will depend on how a particular player behaves. In the case of your 30" Sony, if it is a CRT, I can well imagine that the picture through HDMI was nothing special. The main advantage of HDMI video is keeping the signal in the digital domain at all times, which a CRT can't do. HDMI and DVI certainly favor fixed-pixel displays. Let's also not forget that the primary reason for DVI and HDMI was to enable copy protection, not to improve your DVDs. I do not argue that manufacturers have perfected digital transmission and scaling; many things can, and do, go awry. As a case in point, my own Sony outputs an incorrect HD color space for upconverted material--instead of an SD color space--which results in a depression of the color green. My LCD, however, can live with this flaw. Other monitors aren't so forgiving.

My first cable couldn't handle the bandwidth for the upconversion. It would output only 480p, which also looked breathtaking, but it shouldn't have been the only option. At first, I didn't know that the cable was responsible. I asked Sony what might be wrong. Sony's answer was that I should be getting 720p and that the most likely culprit was the cable. Voila, a new cable permitted the proper scaling, that is, until the 975 locked up and refused to read anything. The reputable manufacturer of my first cable (Pacific) acknowledged a bandwidth limitation in the early production run of their HDMI-DVI adaptor, which apparently has been rectified. The current model can handle HD resolutions.

You'll notice that I urged anyone interested in the HDMI/DVI players to do research before buying. I never tried to whitewash the existing problems, but with the right combination of monitor and player, the results can be worth the possible minor drawbacks in color, centering, aspect ratio control, etc. Personally, I like the upscaling feature. Because it can't create true HD, the degree of difference between digital 480p and 720p may not under all conditions add up to much, but in some cases, testing has shown--in the Snell and Willcox screen for example--that lines may resolve a little better.

If you're certain that I don't know the facts, so be it. People who have an interest in this issue should range as far and wide into the literature and personal experience as they can. You and I slugging it out on the subject won't be of much value to anyone, including us.

Ed

[jocko_nc]

Come to think of it, I am pretty sure my TV is doing an upconverstion already. Toshiba 52HM84.

Here is what I am taking from this...

The current DVD technology intentionally limits the resolution of the video and perhaps the audio. Copy protection is a real problem. Upconversion may result in a sharper picture, but not necessarily. This can be done in the DVD player or on the TV.

HD DVD is technically achievable, though the industry is not sure how to handle it yet. It will come out someday...

HDMI at this point means very little. A DVD player w/ HDMI out most likely pumps the same same quality of signal over a much more complicated pathway.

Another question:

It does kind of tick me off when "copy protection" results in the inability to view what I have purchased or the quality to which I can view same. I had this situation over the Holidays when staying at a ski rental. I wanted to watch a DVD with a portable player. The only TV available was an old unit with a coax input only. They did have an old VCR connected, with composite video input. You know the rest, no way to pass the DVD through the VCR. Copy protection. Greedy bastards.

With all the software out there, is there any way that a ripped, cleaned, copied, pirated, whatever you want to call it, DVD might actually play better because the copy protection might have been eliminated? Acedemic curiousity only, pertaining to the digital copyright debacle. It would be ironic, wouldn't it...

Thanks,

jocko

[edtyct]

The current DVD technology didn't intentionally limit the video resolution; it represented the upper boundary of NTSC at the time of its creation. Even though HD DVD capability has been in development for some time, movie studios were not eager to have it unleased on the market until adequate copy protection existed. With HDCP firmly in place, HD DVD will appear later this year (though in competing formats).

As Mr Peabody points out, HDMI is problematical as a delivery medium at this point, because manufacturers haven't ironed out all of the wrinkles yet, though its enabling of HDCP is a done deal. However, whereas Mr P thinks that HDMI is a conspiracy among studios, reviewers, etc. to dupe consumers, I, and others, are excited about it. Even at 480p, it allows a signal to be transferred to a suitable digital display without any analog artifacts, which--on a level playing field--can result in a smoother picture. Though an upconverted DVD signal is still based on 480p and can't exceed the original information, tests show that it can improve sharpness both subjectively and objectively. Whether the benefits outweigh the drawbacks in particular applications at this point is a matter best left to the individuals involved. Personally, I like the way my Sony DVP-NS975V upconverts to a rear projection Sony LCD, though I am less thrilled with the fact that the color space is flawed and the player's reliability a question mark. But eventually, the superiority of digital delivery will be a no- brainer. Needless to say, HDCP has to be present on both devices for the signal to transfer.

So far as audio goes, the DVD format as we've known it embodied unavoidable technical limitations. Without lossy compression (a way to cut bits and still convey adequate sound), as implemented by Dolby Digital and DTS, 5.1 channels of audio would not have fit on a single disk along with the video and any extra features. As a result, the DD and DTS on our DVDs embodies considerably less data than our original PCM CD system. The advantage of HDMI in this respect is that it has enough bandwidth to carry both HD video and HD multichannel audio, let alone the 5.1 or 7.1 channels on our DVDs now. However, the fact that only TV sets have HDMI inputs, not many pre/pros or receivers, means that HDMI's capacity is largely going to waste at the moment. TVs normally provide only 2 channels via HDMI. Mr P seems to suggest that, despite its potential, HDMI as currently implemented carries only 2 channels regardless of the components involved. Maybe that's true, although I've heard of this limitation only as a correctable firmware glitch with certain components.

The last time I checked, the Macrovision scheme on DVDs took advantage of the fact that NTSC video uses only about 480 lines of the 520 total by relegating the extra 40 lines to carry the protective scheme. The result is that copying devices, like VCRs and some digital ones, pick up this macrovision encoding via the analog outputs of the source and translate it into something unwatchable. For the most part, TVs operate quickly enough to avoid this scheme, so the protective garbage doesn't affect the quality of the disk. When macrovision isn't enacted, or isn't included on a disk, a DVD or tape doesn't suffer from any deterioration when played. Hackers have been getting around macrovision for years, though the fact that the average user can't copy at will apparently has been satisfactory for content providers, which is ironic enough.

Incidentally, the HDCP built into the digital output stages of TVs, STBs, and DVD players works on an altogether different principle; it has nothing to do with a disk or a program per se. It has no affect on the quality of a picture displayed at 720p or 1080i; it just prevents it from being duplicated in a format indistinguishable from the original. You can see why it wouldn't apply to NTSC standard video but would apply to upconverted HD resolutions, even if they aren't true HD.

Ed

[Mr Peabody]

Limited bandwidth in the HDMI cable is another factor I never even thought to check. I assumed if it was HDMI it would have the appropriate bandwidth. I'm using a Monster. It ran about $100.00. I don't have the package anymore, I hope it will do what it's supposed to for $100.00. My Sony 30" TV is a tube. It is incredible. I also need to check to see if the screen settings can be or need be changed. I didn't see anything in the owner's manual initially about being able to switch from 720p or 1080i.

My Sony ns975v done the exact same thing. But the dealer nor Sony gave me any indication, or fess up, to a bad batch. I saw on the internet others had problems though so I got my money back. If they would have been honest about the problem and told me some are coming with the problem eliminated I would still have a Sony. I actually like the Sony better than the LG. LG is marketed as a better than average brand or a contender with some of the best in TV/DVD but I'm not quite convinced. I talked with a guy who was in the Army and previously stationed in Europe and he says LG is big over there. I was also afraid to buy the Toshiba 5970 because of bad reports. I didn't want to pay $399.00 for the Panasonic. The way technology is changing I think my days of buying expensive DVD players is over. Much of the price on these players today go into the DVD-A/SACD which I'm not using. I have also read many reports that using the DVI adaptor did not have good results. I know in theory there shouldn't be a problem but many seem to have had them anyway.

You and I probably do way more research on these matters because it's our passion but the "average Joe" doesn't and I think it's a crime for something like HDMI to hit the market and defraud the public. At a minimum it's being misrepresented on the retail floor floor and I don't think that's an accident. To me HDMI is a prime example that the industry's take the consumer for granted and it would seem rightly so. I mean, we keep buying into whatever they put out, we fanned the flame of the mass merchant buy trying to save a dollar. Now you can't find customer service anymore because the small retailer who might have cared if you come back again is gone. BUT, I digress.