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PLEASE NOTE: The following is reposted by request to get it at the top of a thread. It was originally written as a reply to Texas_Longhorns who asked for a crash course on "HD DVD" and was really trying to get his head around the very confusing marketing hype currently out there regarding up-scaling DVD players, "high definition" DVD discs, digital connections, "new" HD DVD technologies and the like, and just what the heck people really meant when they bandied about the "high definition" catch phrase. He was planning on buying a DLP with 720 native resolution and was wondering just what would or would not work with that TV, and whether he had to discard his existing DVD library.
--Bob
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TL,
Your DLP (when you get it) has a fixed number of pixels that can be lit up to varying degrees of brightness to produce the color image on the screen. This is the "native" 720 resolution of your DLP. [Actually for technical reasons, the "native" resolution is more likely to be 768, but you can ignore that difference for now.]

[EDITED TO CORRECT (2/25/05): Oops! See post #146 below -- thanks to C1courtney. Although many fixed pixel technologies use actual "native" pixel counts that are influenced by what goes on in the computer world -- such as 768 or 788 line count matrices -- DLP displays do not. They use a true 720 line count matrix.]

No matter what you decide to watch, no matter what the resolution, the DLP needs to decide which pixels to light up. The circuit that does this is called a "scaler". The scaler works both ways. It can take a 480 signal or a 1080 signal and produce from it the 720 signal that it requires when lighting up the pixels. It does this using math -- more or less cleverly depending upon the quality of the electronics -- and tries to do it so well that the eye is fooled into thinking no conversion has happened. The scaler often operates even if the display is fed a 720 signal because of that 720 vs. 768 difference I mentioned [EDIT: for some display technologies].

The scaler's job is complicated by two additional factors. First, your DLP is a wide screen TV and some of the content you will be watching is recorded in the shape of a conventional TV. The various stretch and zoom modes of your DLP come into play here.

Second, a conventional TV signal is only sent half a picture at a time. One half contains all the odd numbered lines of the image and the other half all the even numbered lines. This "interlacing" of the picture is due to historical limitations on the cost of the electronics and the available bandwidth for conventional TV broadcasts. Older TVs would paint the image on the screen one half on top of the other in two passes, doing it fast enough that for the most part the eye gets fooled into thinking the whole image is there at once. But conventional TV is not all that great and the eye frequently sees the gaps between the image lines and other artifacts resulting from this 480-interlaced or 480i signal unless the set is adjusted to blur the image to conceal them.

Some years back, manufacturers decided they could sell TVs for more money if they put in circuits to try to make an interlaced signal look better, i.e., if they could do a better job of hiding the damage to the image done by interlacing than just blurring the image. The first of these were "line-doublers" that did just that -- they filled in the gaps between the lines using the data sent in each half image. That was quickly followed by "de-interlacing" circuits that stored the first half image until the second half image arrived and then constructed a FULL image from those two halves and painted the whole thing at once on the screen. The result was a "progressive scan" image which was painted progressively and smoothly from top to bottom without having to go back and do a second interlaced pass, and the resulting signal was called a 480-progressive or 480p signal. Such TVs used digital processing circuits which were just becoming cheap enough for home TV and produced a noticeably crisper image because there was no need to blur the scan lines.

"De-interlace" processing turned out to be surprisingly hard to do well. The two image halves were recorded by the video camera slightly separated in time, and thus they weren't really parts of the same picture but rather a double exposure of a slightly motion-blurred picture. And again for cost and bandwidth reasons (as well as compatibility with old black and white TV), another corner was cut in that the white to black gray scale which makes up the fine resolution detail of the picture was recorded at a higher resolution than the color data, which made it hard to figure out which color to use when reconstructing each part of the image from the two halves that were recorded slightly separated in time.

And the problem is that the math in a scaler depends upon the quality of the de-interlacing. They are both supposed to assume, and be optimized for, "natural moving images" and if the de-interlacing is faulty then the resulting artifacts in the image will mess up the result from the scaler as well.

A typical conventional TV today will also have a "native" resolution even though it doesn't have a fixed set of pixels such as your DLP. For technical reasons that will often be a 540-progressive or 540p signal. Your DLP likely has a native resolution of 768p which the marketing people will describe as being optimized for 720p because that is one of the "standard" resolutions for high definition television. [EDIT: As noted above, this last statement is not correct for DLPs although it is quite often the case for other fixed pixel display technologies.]

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Now here comes the content!

Standard definition television, whether it comes from your roof antenna, your cable service box or a satellite, is a 480i signal. This is true even if you have "digital" cable, or subscribe to satellite TV services which are inherently "digital". In fact such digital services often "compress" the signal to fit more channels into the available bandwidth which damages the signal. But since normal off air broadcasts and analog cable are subject to all sorts of other damage -- noisy signals, interference, ghosting, etc. -- the compressed digital signal still looks better which is why people pay for it. But the ORIGINAL signal is still 480i. It contains images which are the shape of a conventional TV -- a "4:3 aspect ratio".

DVDs today are ALSO recorded at 480i. ALL DVDs. Even the extra-expensive ones sold under various marketing names such as "Superbit". DVDs that say they are recorded in high definition mean that better quality equipment was used in digitizing the original film content. But the actual data that gets put on the DVD is 480i nonetheless. In fact it is "compressed" 480i like the digital cable or satellite signals. Too much compression (because the marketing guys want to save space for putting "extras" on the DVD) damages the image. The "Superbit" DVDs and their ilk use less compression -- putting a movie on 2 DVDs instead of 1 for instance -- and thus yield a less damaged image. Additional care is taken in the digitizing process as well. But the data on the DVD is still only 480i. DVDs are also designed for 4:3 shaped images. Various tricks are used to put wide screen (16:9) or "wider than wide screen" cinematic movie content on the DVDs. The most important of these is "anamorphic" enhancement which deliberately distorts the wide image so that it fits in the squarer shape without wasting pixels on the top and bottom as unused black bars. DVD players automatically sense and remove this built-in distortion and produce the original wide screen image with better fidelity because there was no such wasted resolution.

So here comes the 480i signal from your source -- complete with color data coming in at only half that resolution or less. Your DLP now wants to scale it up to 720 [EDIT: or 768p for other common fixed pixel display technologies]. First the signal goes through the de-interlacer and comes out as 480p. Then the scaler extrapolates the extra resolution it needs -- inventing the intermediate pixels by kind of averaging the real pixels around them. And then the pixels light up. If you paused that image it would not look all that great -- certainly not as good as a photograph. But here comes the next 480i frame and the next and your eye does the final bit of processing by smoothing it all together so that you see an attractive moving image. The brain is remarkably good at making a silk purse from a sow's ear here, which is a good thing since otherwise TVs would never have been cheap enough to take off in the marketplace.

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The next bit of fun and games comes when DVD player manufacturers figured out they could sell players for more money if they put a de-interlacing circuit in the players. They could then send a 480p signal to the TV. They could do this because their cronies (another division of the same company) producing the TVs set them up to take a 480p signal as input, thus by-passing the internal de-interlacing circuit. The logic behind all this was that the DVDs that were being recorded also include special information as to how to do a better job of de-interlacing which the player could see as part of it's processing to produce an analog TV image from the digital data recorded on the DVD. Thus, and this is the important bit, THE DVD PLAYER COULD DO A BETTER JOB OF DE-INTERLACING!

So now you had "progressive" DVD players that would take 480i DVDs -- the only kind that exist -- and produce 480p analog TV signals. The TVs still had their own de-interlacers to handle regular TV signals (which they needed to de-interlace to make their "line doublers" work).

So people would now pay for TWO de-interlacing circuits, plus the extra profit built into bleeding edge technology. And bleeding-edge it was. The idea was fine but the execution was often dreadful. The net result was that the de-interlacing in the DVD players was often WORSE than what the TVs could do on their own. For a variety of technical reasons, de-interlacing the wide range of DVD content out there is a tough job, and on top of that the engineering was often shoddy. So folks would spend the money for a progressive scan DVD player and then turn off the progressive option and use it like a 480i DVD player because that produced a better picture. The picture was "better" because some data was effectively being filtered out -- discarded -- and thus the TV's de-interlacer produced less noticeable glitches. In fact, many DVD players were having trouble just decoding the digital data on the DVD properly. If you'd like to see the sorts of problems that can occur, check out the remarkably detailed information in the DVD benchmarks section of the Secrets of Home Theater web site.

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Nevertheless the progressive scan DVD players had one big advantage -- they sold like hotcakes. Most buyers assumed they MUST be better and thus any problems they were seeing must be due to faulty DVD content and not the players.

They sold so well that everybody else wanted to get in on the act. So now you had cable and satellite boxes and even tape players putting out 480p progressive signals, which was kind of silly unless the de-interlacer in your TV was particularly brain-dead -- in which case your TV probably had a whole bunch of other problems as well. The "better" picture that most people saw with such boxes was almost always just a result of them switching from "channel 3/4" or "composite" video cabling to "S-video" or "component" cabling, both of which include a higher bandwidth signal -- most notably an improved color signal.

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Then came "high definition" TV.

From the standpoint of broadcast TV this was a big thing -- the real deal. This was content RECORDED in higher resolution, digital from inception, and in a wide screen aspect ratio. The industry settled on 720p and 1080i as the new broadcast standard resolutions -- not quite up to the eye-candy of the 1080p they were using for studio masters, but still looking much much better than conventional TV and at a cost the market could be made to bear.

TVs were manufactured that could handle these new signals -- originally expecting the signals to be converted to analog signals over component cables and then including true digital inputs (HDMI or DVI) and internal HDTV tuners. Of course since there was limited HDTV content out there, such sets were often used primarily to watch old, boring standard TV. So to help sell the sets, the marketing people thought up the bright idea of saying the sets would convert standard TV to high definition. This was basically a new way of marketing the old line-doubling scalers (nothing really new here) plus some real advantage arising since the display element and electronics were engineered for higher bandwidth signals in case they were ever fed a real HDTV signal -- that is the TVs were built more to studio monitor standards.

As the "HDTV" buzzword grew, DVD content producers wanted to cash in. Of course their DVDs were still only 480i, but never let the facts get in the way of a good marketing campaign. They discovered that 1080p professional digitizing equipment was being used to digitize the film content -- which was then down-scaled to 480i to be put on the DVD. And that was all they needed to know to call their new crop of DVDs "high definition" DVDs. This while they were compressing the heck out of them (damaging the image) to save space to put CD-ROM games on the same DVD. [I'm being a bit cynical here. Major studios have come a long way towards improving the transfer quality on their DVDs and are only occasionally tempted to let the movie be damaged because they know folks are more likely to buy "special" versions that include extras.]

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Still with me? OK, we've got two chapters to go.

The next big deal is the "up-scaling" or "up-converting" (a misused marketing term) DVD players. The idea is to get people to buy new DVD players for their new HDTV-ready TVs by doing the same trick they did with the progressive players. I.e., let's put the scaler in the player!

Now remember the TV still needs its own scaler for standard def TV. And fixed pixel displays need a scaler for HDTV as well because HDTV comes in different broadcast resolutions which need to be converted to the "native" resolution of the display.

But heck, if you are going to buy an HDTV-ready TV and "high definition" DVD discs, then you certainly don't want to screw up the vibe by playing them on an old "progressive" player. You want a high-tech, high definition, "up-scaling" player! Just in case you've lost track here, the content on the DVDs is *STILL* only 480i in all this.

The drooling from the hardware guys was so great that it took them a while to hear the screams from the content guys. The folks who make their money selling DVD discs don't want high-res content coming out of the players because folks will just make copies of movies and not buy their discs! The HDTV broadcast networks face the same dilemma but they are already resigned to a business model that makes money by selling commercial time and subscriptions. The DVD guys need to schlep discs.

So the boys in building "A" got together with the boys in building "B" and came up with a solution. We'll allow up-scaling DVD players but only if the high res output is limited to digital connections that we can control with a copy protection scheme. The bosses in building "C" got big grins.

Well it turns out there was a digital cabling standard already in place called DVI. It was used to connect computers to monitors and since HDTV-ready TVs now were built to the high bandwidth and sync-rates needed by computers, many already had DVI inputs so that folks could use them as computer monitors as well.

All that was needed was to clamp a copy protection boot on that DVI input. This rejoices in the name of "HDCP".

An HDCP-compliant source device will refuse to make a digital connection to a display or intervening device which is not also HDCP-compliant. Analog connections will work regardless -- but only at conventional, lower resolutions.

So voila you now had TVs with digital inputs and DVD players with fancy new, up-scaling, high-definition digital outputs. Of course there were some older TVs out there with DVI that was NOT HDCP compliant, but the industry had an answer to that. Buy a new TV. Or use your fancy new up-scaling DVD player just as if it were a previous generation progressive player by connecting it via analog cables at 480p resolution. Since it said "up-scaling" on the box the image must be better, right?

DVI had other problems as well due to it's computer-based heritage. It didn't carry audio for example. So new HDMI cabling was invented to deal with that and to remove some other confusions inherent in DVI. HDMI is, more or less, DVI plus digital audio plus HDCP and with connection standards and protocols more or less attuned to the home theater market.

But all that techy, geeky stuff aside, the big news was that these players could put out glorious 720p or 1080i signals from a DVD disc via those HDMI or DVI connections! "Glorious" here being a marketing term of art. The important thing to remember, the thing I have to keep stressing because I see that buying frenzy gleam coming into your eye again, is that THE CONTENT ON THE DVDs IS ONLY 480i AND NO SCHEME CAN INVENT DATA THAT ISN'T THERE IN THE FIRST PLACE!

The 480i data decoded from the DVD first gets de-interlaced to 480p. Then it gets scaled up either to 720p or to 1080p. If the desired output signal is 720p then you are done. If the desired output signal is 1080i then the signal gets RE-interlaced to 1080i. The TV receives a digital 720p or 1080i signal from the player and SCALES IT AGAIN to match the native resolution of the display.

Urrh why are we doing this?

As the character says in "Shakespeare in Love", strangely enough it all works out.

In fact some, by no means all but some, of these new generation "up-scaling" DVD players produce a significantly better image than the previous generation of "progressive scan" players. Why this is so is due to several factors.

First the scaler in the player may be better than the scaler in the TV. The closer the player can get the data to the native resolution of the TV the less work the TV's scaler has to do.

Second, engineering continues to advance. Other factors than scaling are likely to be better in a good "up-scaling" player than in the previous generation players.

But the most important reasons why folks get good results from some of these new players is that the data stays entirely in the digital domain.

A player connected by analog cabling, such as S-video or component cabling, has to convert the digital data present on the DVD into analog TV signals. It usually does this as the very last thing it does -- in the video output stage -- because it is so useful to keep the signal in digital form for any other processing it needs to do first. The TV set receiving that analog signal ALSO wants to do processing of various forms -- which are done more cheaply, and for the most part better, with a digital signal. So the FIRST thing the TV does is convert the analog signal BACK to digital form.

Now these dual conversions introduce their own problems, but on top of that the conversions usually involve filtering of one form or another so that the signals work well across the widest range of source content -- some of which can be pretty crappy.

But an up-scaling player sends a digital signal to the TV which just leaves it in digital form. Thus no conversion noise and no filtering.

Given all that, it would seem natural that the best arrangement would be to use a digital connection for a *480* signal, and just leave it to the TV to do whatever scaling is needed -- once. Curiously, that is not often the best way to hook things up. HDTV-ready TV's are optimized for 1080i broadcast signals because that's how they are often judged in stores. That, plus any advantage that comes from having a better scaler in the player suggests that having the player upscale the DVD data and then feed that to the TV will give a better result even though a second scaling pass may be needed. There are additional advantages if you watch movies filmed in older 4:3 shape in that the player can put pillar boxes around the movie content without loss of movie resolution because the player is sending a higher resolution signal.

The bottom line is that despite the best efforts of the marketing guys to pull a fast one here, many of the better up-scaling players DO INDEED produce a significantly better image on many HDTV-ready TVs. Some of that is due to the digital connection, but some is also due to the combination of de-interlacing and scaling technologies working well to produce a signal the TV happens to be optimized to display. Combine that with other improvements naturally occurring with each product cycle and you get a better player.

But just as with the progressive players, there are some up-scaling players out there which are nothing but hype. Engineered by the school of shoddy, they are just not worth the money. And there are undoubtedly folks who will buy up-scaling players and find they end up preferring the signal they get hooking the thing up via S-video at 480 resolution, simply because their TV does a better job doing what they paid to have the DVD player do.

For the record, I use a Pioneer Elite 59avi DVD player connected HDMI to DVI and sending a 1080i signal to a Fujitsu P50 (30 series) plasma. And I just love it. It's an up-scaling combo that rocks. [For the techy geekies, yes I meant 1080i and not 720p. Go figur...]

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And that's the world of today.

But if you are willing to hang in there for another year, or perhaps two years, the world as we know it will change.

That's because there are two competing technologies lining up to fight the battle to become the new -- TA DAH! -- high resolution DVD format. HD-DVD and Blue Ray differ from current DVD technology in that the data on the disc is actually encoded in high resolution. Such discs won't be compatible with current DVD players. You'll need to buy a new DVD player that truly deserves the moniker "high definition" -- applause from the boys in building "C".

Such a player will output a 720p or 1080i signal -- possibly even a 1080p signal -- but that signal will reflect much more what's actually on the disc and much less the art of the scaler engineer.

Those new players will undoubtedly play conventional DVD discs as well, although they may cut corners on doing that job (despite the high price of the players) since they will really be all about optimizing things so that you'll go and buy new discs.

Which you won't be able to do until there ARE new discs. It's no surprise that the major powers in the battle over which of these two formats will win are the guys who own the movies. Until a sufficient number of new discs hit the stores any such new players will be expensive curiosities.

And of course if you buy a player for the format that loses the war, then you are screwed.

But again, this is for the future. Up-scaling players for conventional DVD discs are the hot item right now. They are at price points from a few hundred bucks to a few thousand. The $1k price point is a real sweet spot right now with big news, new release players coming out closer to $2K, but you can get a fine player for a few hundred if you do your homework. You can also get some real crap, so DO please do your homework.

Hope this helps, and hope you enjoy your DLP when you get it. Just remember that 6 months from now today's electronics will be obsolete, so buy what works for you and enjoy it without angsting too much about what's around the corner.
--Bob

Thanks Bob, I will flag this thread for reference when friends ask about upscaling DVD. And also bump it back up to the top now.

Chris

Originally posted by Chris Gerhard
Thanks Bob, I will flag this thread for reference when friends ask about upscaling DVD. And also bump it back up to the top now.

Chris

Sorry for the dumb question, but how exactly do you "flag a thread?" In the past I've 'bookmarked' (Firefox browser) or added to 'favorites' (I.E) various threads, but wonder whether there is another way to do it within the AVS website.

htomei

Thanks Bob !!,
I have requested that "Crash Course on HD-DVD" be removed and replaced. This way folks don't have to scroll through the post to get to the topic.
Regards,
Steve

ahh man and I felt to famous having a thread up top :p You did the right thing creating this one. I'm sure it was confusing the people who would first open it and read my newbie questions and ponder to themselves "who's this dolt?" :D

Thanks again!

just to add my views to the above: I have seen $40,000 set ups with fine equipment and upscaling and non-upscaling equipment. To my eyes, at least, you can spend quite a lot more money to work 'magic' and get a somewhat better picture on the display. It is not (HD) 720P nor is it 1080I. If things do come together, it looks somewhat better than 480P. On the other hand, if you keep it simple (equipment and money), you can get a very good picture from 480I DVD into a EDTV 480P (display like a Panny plasma). Spending quite a lot more money (and getting the magic correct) will give you a somewhat better picture on a HD display, of course. It is entirely up to person if he wants to spend that extra money. Remember, within 1 or 2 years, you will want a new HD Player to play the new HD DVDs. Mostly, I suppose, it is a matter of priorties. Bottom line, the 'magic' works (to varying degrees) but at a cost. A thought here..If HD DVDs catch on big, will there be much trade in value on much of this upscaling equipment? Just a thought, nothing more.

Bob should get paid royalties for work like this. :)

Bob, By the way, great and extensive work my friend. Much more than I would ever attempt to tackle here.

Originally posted by htomei22
Sorry for the dumb question, but how exactly do you "flag a thread?" In the past I've 'bookmarked' (Firefox browser) or added to 'favorites' (I.E) various threads, but wonder whether there is another way to do it within the AVS website.

htomei

Sorry for the confusing terminology, I just added it to favorites with IE 6.0.

Chris

Nice work -- took a confusing topic and made it clear, readable, and understandable.

By far one of the most useful and informative threads on avs. Excellent work.

-GG

Do the upscaling DVD's also change the aspect ratio so as to fill the 16:9 screen ? That is if I put a 2:35:1 DVD in the player and use 720p or 1080i output selection does it change the aspect ratio to 1:77:1 ?

Trunorth,
There's no reason the player, or more normally the TV, couldn't distort the image by doing stretch/zoom processing to make a "wider than wide screen" movie fit into the 16:9 "wide screen" shape, but currently the trend is that neither players nor TVs do that with the high resolution signals sent over the digital connections. This is partly to keep the cost down and partly because marketing research believes folks viewing these high-res signals want to see the movie undistorted -- even though that means there are black letter-box bars top and bottom.

The signal coming from the player will be at most a "wide screen", 16:9 signal. The content on the DVD, even if it has been anamorphically enhanced, is also at most a 16:9 shape. That means a "wider than wide screen" movie INCLUDES black letter-box bars -- IN THE CONTENT recorded on the DVD -- fleshing it out top and bottom to a 16:9 shape.

The simplest way to make such an image fill a 16:9 screen is to "zoom" in on it -- intentionally discarding some of the image left and right and stretching the image to fill the screen top to bottom. You could also "unstretch" or "compress" the image left and right to keep from losing those parts of it off the side but that would distort the image -- i.e., circles now look like ovals. This compression could be uniform across the image or could be concentrated to the sides so that the center of the image is less distorted.

It's all just math, and basically part and parcel of what a scaler already does. And that's just what's going on if you apply stretch or zoom distortion to these images at lower resolutions or when you apply it to a 4:3 image you are trying to expand to fill a 16:9 screen.

Since there is a market out there for folks who prefer to see distorted or partially cropped movies rather than undistorted movies with letter-box or pillar-box bars, I wouldn't be surprised to eventually see upscaling players or true high definition DVD players (when they are eventually launched in a year or so) offer this -- or more likely for new HDTV-ready TVs to offer it on their digital inputs at high resolution -- but that's generally not the case today and it will add some cost when it is added. The only limiting factor is the processing power of the available scaler electronics.

Today, if you want to watch "wider than wide screen" content from an up-scaling DVD player at high resolution, you should expect to see letter-box bars top and bottom and should expect to find no option, either on the player or the TV, to distort the image so as to eliminate them. Your workaround is to switch to lower resolution -- and quite possibly also switch to analog cables -- so you can get at the scaler options (usually on the TV side) to do this distortion.
--Bob

Bob - you have now answered what I couldnt get a straight answer to from a number of AV stores. Great site, great people. Thanks a bunch, appreciated.

Regards,
Trunorth.

Thank you for one of the best reads that I have had here at the AVS forum. You're article put into words what has becoming increasingly more apparent now that I am the owner of a Sharp 45 1080P LCD: that inventing data which is not there is very difficult. Especially with the Sharp 45 which has double the pixels to fill in than a 720P screen.

Bob!! Awesome post, very thought provoking. I too have the 45 inch Sharp LCD and have been contemplating picking up an iScan HD+ along side a 1080i DVD player with HDMI/DVI capabilities. After reading your post, I might down-scale (no pun intended) a bit. From what I gathered after reading your article, a scaler would only mildly improve my picture, if at all. My now informed opinion, thanks to you, is that where I might benefit the most is to simply upgrade my DVD player to DVI/HDMI and leave out the analog conversions altogether. Do you have DVD players you would recommend in the sub $500 range or so? Are there websites that you would recommend with detailed reviews of such? Thanks again for your post!!

ckelly33,
The Iscan products are widely regarded as exceptional; among the best scalers you can lay your hands on for home theater. If you shell out the bucks for one, you want to let it do almost all of the work. That means you want to send it a 480i signal from the DVD player -- i.e., bypass any de-interlacing or scaling that the player might offer -- and have it send out the true, "native" resolution of your display so that the scaler in your display has nothing to do either.

However, the industry has conspired to make this rather difficult to do. First, many HDTV-ready TVs don't actually accept their "native" resolution as an input option. You have to feed them a standard resolution such as 720p and let their internal scaler take it from there. Those that do take one of the "unusual" resolutions such as 768p as input, may only do so over their analog, component inputs -- or may treat it like a "computer" signal which means you may have problems getting blacks to work completely right (the analog black level and the analog/digital "blacker than black" data crush problems). And thus you have to expect some hassle over dealing with blacks and/or some quality loss from dual analog/digital conversions -- although less than is typically the case when you connect a typical player to a more conventionally designed TV since the Iscan does it's end well, and the TV allowing such a signal probably does a better than average job at its end.

Meanwhile you'd like to send that 480i signal from the player over a digital connection to the Iscan. Well that's a nuisance as well. DVI doesn't support 480i. The lowest it goes is 480p which means you are depending upon the de-interlacing in the player. HDMI *DOES* support 480i but this feature is often not enabled on players because marketing fears the problems people will have if they do the common connection of an HDMI output to a display's DVI input. [The Pioneer 59avi is one of the better regarded players that DOES allow 480i output via HDMI.] And to get HDMI or DVI you have to pay the premium for an upscaling player ANYWAY, which is a feature you don't intend to use.

So some folks send their players to places that open them up and do a modification to add a different type of digital output called SDI -- which is a 480i-specific digital connection that is about as close as you can get to just passing along the digital data from the DVD directly. Of course such a modification voids the warranty on your new player.

In any event, you have to decide what player to get, given that the latest and greatest stuff such as new, higher end analog video output stages and support for exotic audio discs will generally be offered on the newest up-scaling players which now populate the top end of each manufacturer's lineup of players. Or you may decide to save cash and get an older, or less adventurous, progressive design -- which might have old bugs not yet fixed or might be deliberately crippled with lower quality electronics or missing features since these are now the LOWER end of any given manufacturer's lineup, and the manufacturer needs to differentiate them from his more expensive products.

You will be primarily interested in the quality of the mechanical systems, of the MPEG decoder (the circuit that interprets the compressed digital data on the DVD), and of the video signal output stage -- particularly if you are using analog component outputs. Some older progressive players do this very well, and some have serious flaws in these. But as should be obvious, plunking down the cash for a new design is not a guarantee you won't encounter problems here either. And of course any design can have serious engineering flaws such as inadequate sized or shielded power supplies. The school of shoddy has many disciples.

And then Iscan has units that take component analog signals and SDI signals, and will soon have a unit that takes HDMI -- which I'm pretty certain will mean 480i over HDMI if your player is actually willing to send that as output. So you need to decide which way you want to hook things up.

But in doing all this you are operating on the very edge of what you can do with the 480i data that's on the DVD to begin with, and many of the refinements you will get when you fend your way through all this confusion will only really be seen if you blow up the image really really big such as with a large screen front projection system. That is, on a 45 or 50 inch display, you can go through a lot of effort for not much reward over what the scaler in your good display and/or good, up-scaling player can do for you directly. Now to be clear hear, the image really will be measurably better -- and a skilled eye will be able to see the improvement in certain areas of certain scenes -- but you may very well not see it yourself. It is, after all, only 480i data to begin with.

Heck there are plenty of folks out there happily using BROKEN progressive players who blithely ignore the problems on screen because the image looks better than their normal broadcast TV and what they might have had from older players that were, unbeknownst to them, even MORE broken.

The best thing you can do is go try some combos yourself. Borrow or buy a DVD player from a place with a liberal return policy. Take a DVD player to the store when you go look at displays. And remember that no combo of player and display is going to look its best until you learn how to adjust (calibrate) the basic levels of your display using a calibration DVD such as Avia or DVE -- and in particular how to extinguish the "torch" modes on the TV.

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

I don't have any personal recommendations to offer on the less expensive players because I'm not sufficiently familiar with them. But the information you will find on this forum -- and the test results pointing out possible issues which you may or may not be sensitive to which are to be found in the DVD Benchmarks section of the Secrets of Home Theater web site -- are really your best sources of info. Among the less expensive players, a few models from Zenith, Panasonic, Denon and Sony are currently highly regarded on this forum, and I've probably left out a few. Do some Searches here and you will find lots of discussion on just this topic.

=======================================

EDIT: I should add that there is a whole forum here dedicated to the fascinating world of video processors such as the Iscan products. Technical questions and recommendations regarding such beasties are best handled over in that forum.
--Bob

As always Bob you are one of the top contributors here at AVS. I appreciate your knowledge and patience with my questions and others.

Note to mods.....

We see a ton of redundant threads on upconverting and HD resoluiton threads.....could this be the one area to send all of those members to?

What I would love to see is the Mods close the redundant threads on this topic and send them to this thread for discussion.

Bob - Could you explain what is going on with my HTPC which is displaying a 1920X1080P desktop on my Sharp 45 via a NVDIA 6800 when I play back a dvd ripped down to my hard drive using dvd shrink and played back using TheaterTek 2.0. How is this different than using a sdi modified dvd player and a scaler?

Bob

Your information is incredible. However, you speak a lot about native resolution. I just purchased a Sony KD34XS955 which is a 34" high def widescreen tube job. It has HDMI input. Since it is not a fixed pixel device does it have a native resolution and what would be the best DVD output to send? I am shopping for a DVD player this week. The forums have me concerned about Chroma Upsampling Error, Macroblocking, Black Crush (whatever that is), etc. Also, when I purchase the HD Direct TV service I assume that will also have an HDMI output from that box. Since the TV only has one digital input, which one do I run to the TV or do I have to spend $250 for and HDMI switcher?

Chavel,
I'm not sufficiently familiar with HTPC to help you on this. It's possible others on this forum might know the answers but you also might want to try this question over on the video processor forum here.

Of course the SDI modified side is comparatively straightforward. Your player is decoding the DVD (one possible source of errors) and then sending that digital 480i signal via SDI to your external scaler. The scaler de-interlaces that signal to 480p and scales it as instructed -- preferably all the way to the exact, native pixel count of your display. Ideally you would want the scaler to send the resulting signal by a digital connection (HDMI or DVI) to your display. The quality of the signal will be primarily the result of how good the external scaler is unless your player has one of the various MPEG decoder bugs. Your display may be doing other processing to the signal before it lights up the pixels -- color or gray level biasing or automatic adjustment, noise reduction, gamma correction, etc. Ideally you want the display to do the minimum necessary stuff to get the proper calibrated levels with a smooth gray scale ramp. You certainly do NOT want anything that adjusts colors or over-all light levels "on the fly" according to what sort of image is currently being displayed. In particular, turn off any "flesh tone correction" or "noise reduction" or "automatic gain control" stuff. These are for making crappy signals look better and you don't want them screwing up a high quality signal such as is coming from your scaler. Also be careful your display is not doing excessive Sharpness processing. You want none of this stuff to be happening on the player side as well, but depending upon where the SDI mod taps into the signal path that may be before any of that could possibly happen anyway.
--Bob

soundman11,
HDTV-ready CRT-based displays are not "fixed pixel" displays, but they generally have "preferred" resolutions anyway due to optimizations that have been made in their internal processing circuitry. Typically a current CRT-based TV design will scale 480 signals to 540p and will display HDTV signals at 1080i. It is not unusual for such CRTs to have rather strict limitations on the signals they will accept -- often limited to one of 480i, 480p, or 1080i. In particular they may require that the HDTV input signal be 1080i and not 720p. Other such TVs will accept 720p and scale it to 1080i, or may even have "computer" inputs that take other resolutions but may have problems handling black levels properly if you try to use them for home theater. The component inputs on such a TV will accept all these non-computer resolutions. The digital inputs may be limited to just the HDTV resolutions, meaning perhaps only 1080i, or may also accept 480p or 720p as well. Your user's manual should tell you what resolutions are allowed on each type of input.

So for standard definition TV you are not likely going to be able to feed the set it's preferred 540p signal since it won't accept it. Use 480i or 480p depending upon the quality of the de-interlacing in the external source device.

For high definition TV, you will likely want to feed the set it's preferred 1080i signal over either analog (component) or digital (HDMI or DVI) inputs. Your HDTV set top box will undoubtedly offer a 1080i signal on it's component outputs, and if it HAS a digital output (not all do) then that will offer 1080i as well. Your set top box would then handle the scaling to 1080i of any 480i (standard def TV) content or 720p (alternate HDTV resolution) content to 1080i before sending it out that output. Some set top boxes offer the option to pass through whatever the current broadcast resolution happens to be on any given channel. But that's only useful to you if your TV will actually accept all three -- 480i, 720p, and 1080i -- on the input you've decided to use.

If you get an upscaling DVD player, it will offer the ability to upscale the 480i DVD content to 1080i, but it will likely only output that on it's digital output. Whether that produces a better image than sending the original 480i signal from the DVD, or the de-interlaced 480p signal produced by the "progressive" circuit which is also in any upscaling player, depends on the quality of what the TV does with such a signal compared to the quality of the 1080i scaling in the player -- as described in my earlier post. But generally the digital connection helps enough that sending a digital 1080i signal is well worth trying -- and the CRT TV won't have to do any additional scaling when fed that signal -- which is a good thing.

In particular, note that HDTV-ready TVs of all flavors are often optimized in various ways for a 1080i signal since that's the signal the manufacturer expects to be used to judge the set in stores. Depending upon how many corners the manufacture cut as regards other input signal types, this could bias the set towards wanting 1080i more than just about anything else -- sometimes even including the real, "native" pixel count of a fixed pixel display. Countering that is that some TVs limit the user controls available if the signal is 1080i because the internal processing circuits aren't fast enough to do it. Thus if you like to stretch and zoom DVD content a lot, you may find it better to hook up at lower resolution so the TV can do that for you before scaling up the image.

If you only have one digital input on your TV you should first think of dedicating that to the source you want to watch most critically. For many folks that will be HDTV. For others it will be DVD movies. Keep in mind that your HDTV box *WILL* send a 1080i signal over it's analog component outputs, so if you dedicate the digital input to the upscaling DVD player then the set top box can still send HDTV via component. On the other hand if you connect your HDTV box to the digital input, the DVD player's component output will send only 480p (except for a couple very unusual players) and thus you are paying for the upscaling feature in the player and not using it.

HDMI switches are expensive but only like cables are expensive -- it's still a relatively small cost compared to what you've already spent on other gear, which is how they get away with making the price so high (extra profit) to begin with. Before shelling out for a switch, you should calibrate both styles of connection for both sources and see for yourself whether connecting both of them via the digital input is worth it in terms of a picture improvement that you, personally, can see. Keep in mind that you have to separately calibrate each combination of source, display, and choice of cables, and you should even double check the calibration is still right if you just change resolutions.

If all of this sounds complicated, well it is. There are lots of possible choices and unexpected limitations may rear up on any of them. The good thing is that trying different combinations is not hard, it just takes time.
--Bob

Bob,

Thanks for such a great write up. It really was a very informative post. However, I think we really need some visual evidence about what up scaling and interpolation can really do. So here is a thread that shows the difference between a DVD that is simply scaled to 1080i and the same DVD that is scaled to 1080i with some very sophisticated interpolation on a Home theatre computer. I think the pictures speak for themselves. Up scaling stand alone DVD players might not give you that HD WOW factor but a properly tuned HTPC can come pretty darn close.

http://www.avsforum.com/avs-vb/showthread.php?s=&threadid=467585

Let me see if I have this right...

I have a rear projection HDTV (tosh 51hx83). If I bought either a progressive scan or upscaling DVD, I would only have an improvement in picture quality if the scaler from the DVD player is better than the scaler already built into my TV?

Here comes a couple tougher (I think) questions... Assuming the DVD scaler is better than my TVs and both scalers are equal... Would there be a disadvantage of buying one of the few players that scale over component over one that scales over DVI? I guess the question also could be stated, does the TV simply pass a signal whether or digital or analog that is already matched or if it gets an analog signal does it need to convert it to digital, upcale it to 1080p, then back to 1080i prior sending it to my tv?

What does my TV do if I send it a 1080i digital signal? does it do any conversions?

Personally I see no difference between the DVI or component HDTV signal from my cable box. I'm asking because I'm trying to decide if I should upgrade my DVD player or not.

Let me see if I have this right...

I have a rear projection HDTV (tosh 51hx83). If I bought either a progressive scan or upscaling DVD, I would only have an improvement in picture quality if the scaler from the DVD player is better than the scaler already built into my TV?

Here comes a couple tougher (I think) questions... Assuming the DVD scaler is better than my TVs and both scalers are equal... Would there be a disadvantage of buying one of the few players that scale over component over one that scales over DVI? I guess the question also could be stated, does the TV simply pass a signal whether or digital or analog that is already matched or if it gets an analog signal does it need to convert it to digital, upcale it to 1080p, then back to 1080i prior sending it to my tv?

What does my TV do if I send it a 1080i digital signal? does it do any conversions?

Personally I see no difference between the DVI or component HDTV signal from my cable box. I'm asking because I'm trying to decide if I should upgrade my DVD player or not.

Wow, best information I had in reference to upscaling players, this page definetly got bookmarked. Now I can answer the questions accordingly. Thanks

Thanks for a very informative and well written presentation. I was into high-end audio as a hobbyist for decades until I got into the home theater scene. I had fallen out of touch with what was going on in the industry over the past few years and it appears that a lot has been happening in my absence. I was a charter subscriber to The Absolute Sound way back in the early 70's and signed up for The Perfect Vision when it first came out. My family life and budget constraints got me away from the temptation of wanting the latest and greatest gear so I discontinued my subs to both publications along with some of the other mainstream pubs like Video, Video Review, and Sound and Vision.

I just recently got the bug to get a Hi-Def TV and bought a Hitachi 60VS810 LCD RPTV based on personal audition and feedback in these forums. I wanted to be able to properly calibrate the TV via the HDMI inputs as I also have two Hi-Def Tivos so I began looking at some of the newer DVD players. This thread, among others, has filled in some serious gaps in my knowledge of the current state of the art but I see that I still have a lot of catching up to do. It's threads like these that make it worthwhile to sift through the myriad posts to find something meaningful and informative.

Bookmarked for reference! :D

Superfish,
I believe your Toshiba is a CRT-based, HDTV-ready, rear projection TV. Since it is CRT based it doesn't have a fixed set of pixels and thus scaling is only done for other reasons of convenience in the electronics.

In particular, if you feed this TV a 1080i signal, it likely does no scaling on it at all. If you feed this TV a standard definition TV signal (480i, or de-interlaced to 480p as from a progressive scan DVD player), then it likely scales it to 540p -- actually a version of a de-interlacing line doubler circuit.

Essentially the set has TWO "native" resolutions.

I did some testing recently with a different Toshiba model CRT RPTV and to my eye I preferred the 1080i digital signal from a Pioneer Elite 59avi DVD player, a Denon 5900 DVD player, and the HDDirecTivo combo set top box (HR10-250). For the two DVD players the alternative is to send a 480 signal via component analog cabling, but the HDDirecTivo will also send 1080i via component.

Keep in mind that if you send a 480 DVD player signal to your set, it won't scale it up to 720p or 1080i like a flat panel would do. It will use its other "native" resolution of 540p, which can look very good. But on the testing I did, I felt the reduction in filtering of the signal that I got with a digital connection at 1080i produced better real sharpness and naturalness of the image with less sharpness enhancement needed.

As for the players that put out 1080i via analog component cabling, there are only a few models that do that and none are considered in the top tier of current DVD players (although they are by no means in the bottom tier either). But the industry is against such players so I'd be cautious. In particular, Zenith has already changed the firmware in their player to disable this "feature". Now you CAN reload the old firmware to get the feature back, but that re-introduces some bugs the new firmware fixed. And in particular, if Zenith fixes other bugs in the future, the new firmware with those fixes will likely ALSO disable component 1080i. And so you either live with the bugs or lose component 1080i.
--Bob

You all are KILLING ME!! I just bought my Samsung 61" DLP Set (HLP6163W). After watching HD on Comcast cable (I used the DVI) and then watched a DVD, I want to get a better DVD player! SO, here I am looking for a DVD player and here is this thread! I am not sure what the hell to do. But one thing I have learned is never buy the first year model of anything. SO, It will be probably a couple of years before the bugs are worked out of the new players and most importantly, the PRICE is where I can afford it. Plus, what good is my new TV if I dont take full advantage of it now? The High Def DVD players sound good but its sounds like it might be a while before I am able to get one of those..So, to get the best picture out of what I have now, I think I need a new player - I have the Pioneer Elite now - DV-45A ..

Please someone agree.....I am going CRAZY! I just want a great picture on my TV!

Neo9710,
Whatever player you try, it won't look great until you figure out how to calibrate your new DLP for it, i.e., how to properly set the basic whites/blacks/colors/sharpness levels. Digital TVs such as your DLP are more finicky about wanting the right levels, or to put it another way, the picture quality difference between getting the levels right and wrong is quite possible a lot larger than what you are used to from your prior TV. Getting it set properly may give you the really spectacular result you were hoping for.

So before you even consider tossing your old player, it would be wise to invest a few bucks in a calibration DVD such as Avia or "Digital Video Essentials" (DVE) and follow the instructions. The process is not hard, it's just a little confusing at first and it does take some patience.

In the process, be sure you turn off the "torch" modes settings which are likely to be the factory defaults on your TV, as most TV manufacturers like to ship their TVs set to be too bright/contrasty, too red, and overly sharpness enhanced in an effort to attract people to them in stores. Generally you want to select a picture mode identified as being right for "movies", and then start from there to calibrate the levels. Calibration is specific to each combination of source device and TV and choice of cabling, and should even be double-checked if you just change resolutions. Again, the factory default settings are likely *NOT* the ones you really want here either for picture mode or the basic levels.

With the levels set right, your current player may look just fine on your new TV. Probably not as good as HDTV, but certainly a lot better than standard def TV coming out of your cable box. If not, THEN you can start hunting for a new player.

There are a number of good players discussed on this forum at various price points. But first make sure you are getting the best out of your current player so that you have some real basis for comparison when you try a new one (which includes re-calibrating for the new player).

By the way, if you are going to try out new DVD players in stores, it is perfectly reasonable to bring your calibration DVD along and spend the first few minutes making sure the TV they've got it hooked up to in the store is set right. Once you get used to using the calibration DVD, the process for getting the set into the right ballpark only takes a few minutes -- mostly figuring out how to use it's remote control and menus. Then you can play some DVDs you are familiar with (bring them along too) and see how the new player reacts. It's best to do this at a time when the store is not too busy -- e.g., the Christmas shopping season is not the best time to expect a relaxed, contemplative atmosphere in your local shop.
--Bob

Bob, I was just thinking about that same issue. I am looking for it as we speak.. Its time to start tweaking the picture...

Originally posted by Bob Pariseau
HDTV-ready CRT-based displays are not "fixed pixel" displays, but they generally have "preferred" resolutions anyway due to optimizations that have been made in their internal processing circuitry. Typically a current CRT-based TV design will scale 480 signals to 540p and will display HDTV signals at 1080i....

If you get an upscaling DVD player, it will offer the ability to upscale the 480i DVD content to 1080i, but it will likely only output that on it's digital output. Whether that produces a better image than sending the original 480i signal from the DVD, or the de-interlaced 480p signal produced by the "progressive" circuit which is also in any upscaling player, depends on the quality of what the TV does with such a signal compared to the quality of the 1080i scaling in the player -- as described in my earlier post. But generally the digital connection helps enough that sending a digital 1080i signal is well worth trying -- and the CRT TV won't have to do any additional scaling when fed that signal -- which is a good thing.

In particular, note that HDTV-ready TVs of all flavors are often optimized in various ways for a 1080i signal since that's the signal the manufacturer expects to be used to judge the set in stores. Depending upon how many corners the manufacture cut as regards other input signal types, this could bias the set towards wanting 1080i more than just about anything else -- sometimes even including the real, "native" pixel count of a fixed pixel display. Countering that is that some TVs limit the user controls available if the signal is 1080i because the internal processing circuits aren't fast enough to do it. Thus if you like to stretch and zoom DVD content a lot, you may find it better to hook up at lower resolution so the TV can do that for you before scaling up the image....

--Bob

Nice posts, Bob!

Obviously, most of this is intended to serve as a "primer" for those newly entering the complex world of modern video. However, some detail is present and greatly appreciated. An example of detail exists in the excerpts above which includes a statement worth clarifying.

I thought CRT devices were analog -- while LCD/DLP devices were digital. (And, I've suspected the difference had to do with the technology required to light up specific pixels vs. varying the "ray" devices necessary to "excite" phosphors as the rays transversed the inside face of a tube.) Anyway, I thought digital source signals (DVD or HDTV) were converted to analog -- because most display devices (CRTs) expect analog. And, I thought analog signals DROVE CRT displays. If this is true, please elaborate on one of your statements above which begins with: "But generally the digital connection helps enough that sending a digital 1080i signal is well worth trying...".

Upon reading this, my first thought was that you were referring to a lowering of D/A conversions. But, this wouldn't be true for a CRT device would it? I would think quality of the picture would depend on which device has the best scalar and/or the best D/A converter. If so, the digital connection itself would only help -- if it improved on the transmission of the signal from the source device to the display device. And, for the majority of people who locate their DVD player near their TV, wouldn't this improvement be insignificant?

In general, I agree that upscaling players have the potential to improve a video image when the scalar is better and/or if an extra D/A & A/D conversion is eliminated. Also, you make a great point about the continued improvement in technology which may also include improvements in the MPEG decoder. (The technology that figures out what the ones and zeroes on the DVD originally meant). With this in mind, would you consider it appropriate to summarize the potential improvement as being primarily depend on these three variables (scalar, D/A conversion, and MPEG decoding)?

gp

Greg,
You need to throw de-interlacing in there as well.

So the processing chain is MPEG Decoding, de-interlacing, scaling, D/A (or any other video output stage conversion such as color-space conversions which may also take place on a digital output), and then whatever the TV does when it receives the signal.

Now the MPEG Decoding is only going to take place inside the player, so this is something where you are comparing one player against another exclusively. The de-interlacing and scaling could take place in the player or in the TV (or external scaler). So there you are comparing which does the job better when you pair a player up with a TV as well as comparing between players. This last is complicated by the fact that some TVs have to scale the signal again despite what the player did, and that some TVs are going to be optimized for specific resolutions either because that's their native resolution, or for other marketing/engineering reasons -- e.g., we'll filter this input because the source might be crappy, but we'll leave this one unfiltered so that it looks good in the stores when connected to the HDTV feed. Finally there is the video output/input processing such as D/A - A/D conversion.

Now a CRT is indeed an inherently analog device, but modern CRT-based TVs do signal processing anyway -- think of stretch/zoom modes -- and these are usually done with digital circuitry. So even a CRT is likely to convert an analog input to digital form and maintain digital form until it is ready to drive the CRT itself -- at which point it goes back to analog. And again, the D/A and the A/D output/input conversions often involve filtering of the signal.

Another example of processing is the de-interlacing that the CRT does when fed a 480i signal so as to implement its "line doubler" or whatever the marketing guys decide to call it. Again, I think you are going to find most modern CRT TVs doing this in digital circuitry.

Another example is the "on screen display" where the CRT puts text overlaid onto the current video program. Again, this is generally cheaper to do if the video program is in digital form at the point the TV's graphics get overlaid onto it.

Basic level controls could be implemented in analog, but I'm pretty sure these are handled digitally in most designs these days as well.

So even though the display technology is inherently analog, both in its manner of creating various resolutions and in its manner of driving the hardware, the engineers designing the TV will have a strong temptation to use the digital form of the video signal through much of the signal path prior to actually driving the CRT itself. Now of course they could convert to digital each time they want to fiddle with the signal, but maintaining a digital path all the way through is simpler.

Of course I'm generalizing here.

Now a fixed pixel, digital display is, how shall I say it, more digital than a CRT. And that has consequences, some good and some not so good. But generally speaking I think you will find most HDTV-ready CRT displays will look their best when fed a digital signal, although they may cut corners on the features the offer for that style of input. The reason is simply that at the very first time they convert the analog signal to digital -- regardless of the quality of the A/D electronics they use -- they are likely to filter that signal under the theory that just about ANYTHING could be coming in on that analog input. And some video sources are pretty crappy.
--Bob

Thanks for the reply Bob.

Are LCD and DLP devices strictly digital? In other words, does any type of analog signal come into play by the time the video hits the screen? (Audio is not part of the question).

If so, would it be fair to say that all digital devices should eventually be able to outperform their analog counterparts? (And, if the answer is no, then how can a digital signal automatically be presumed as better?)

Also, for those interested, here (http://www.projectorcentral.com/hdtv_edtv.htm) is another great primer on TV/Video.

gp

Originally posted by Bob Pariseau
Your DLP (when you get it) has a fixed number of pixels that can be lit up to varying degrees of brightness to produce the color image on the screen. This is the "native" 720 resolution of your DLP. [Actually for technical reasons, the "native" resolution is more likely to be 768, but you can ignore that difference for now.]

The scaler operates even if the DLP is fed a 720 signal because of that 720 vs. 768 difference I mentioned.
What does this say about the Sony LCD RTPVs which have a native 768 resolution? Many here on AVS rip into Sony for having an "odd" resolution (mid-point between PAL and NTSC), but what you're saying is that all fixed panel RPTVs that claim a native resolution of 720 are actually scaling to 768.

Michael

Greg,
Off hand I can't think of a point where an LCD or DLP design would naturally do signal processing of an analog format signal, as long is the input signal is digital. However the same is likely true of a modern CRT design as well right up to the point where the CRT beam has to be driven.

Now the actual control signals to the display elements have an analog character since they are all physical devices, but this is true to a much greater degree in a CRT where the sweep circuits, beam focusing, and such are essentially analog devices at a more "macro" level compared to the "micro" analog nature of the signal that tells a particular pixel how bright to get even though a digital circuit has selected that particular pixel to be instructed next. In addition the "fixed pixel" displays put a "digital" character to the problem due to their inability to vary the actual display resolution -- everything has to be scaled to match that fixed pixel pattern -- whereas a CRT can vary the scan and sweep rates.

So LCD, DLP, or Plasma designs would naturally carry a digital format signal right to the display driver for the individual pixel. Even the motion processing in a Plasma that adjusts the timing of firing the pixels to correct for delay characteristics of the Plasma color technology would normally be digital.

But a typical CRT design would convert the digital format signal to a true analog signal before passing it off to the analog circuitry that drives the tube.

=====================================

Michael,
What I'm saying is that *THE VAST MAJORITY* of fixed pixel panels sold today, be they LCD, DLP, or Plasma, and regardless of whether they are flat panel, front projection or rear projection format, likely do not have a pixel matrix that matches EITHER the HDTV 720p or 1080i resolutions exactly. Which means they will need to scale either HDTV resolution.

Building, say, an LCD which precisely matches the standard HDTV 720p resolution is by no means impossible, but the trade offs are cost (standard computer resolutions tend to drive the manufacturing of panels -- if you want a non-computer resolution it costs more), potential problems if the display is also to be used as a computer monitor, and potential problems or extra costs in getting the right scaling circuitry for the OTHER signals the TV has to handle such as 480i, 480p, and 1080i -- PLUS, as you point out, potential problems dealing with the different national TV resolutions (PAL vs. NTSC for example). Keep in mind that the manufacturers are designing for a worldwide market and need to try to get the economies of scale of designing components that can be used in products for multiple markets.

Simply put, it's cheaper (from a worldwide manufacturing/marketing point of view) to put in a scaler than to build the panel to fit just one particular market. And of course most customers won't see the flaws in any given scaler.

And indeed if the TV includes a GOOD scaler, the chosen, compromise, panel resolution may very well produce a better quality image across the complete range of signals the customer will likely feed the set -- even though the set doesn't actually match any ONE of those as a "native" resolution.

Now as the volume in the market tilts more towards HDTV use as opposed to computer use, then you will likely find panels (and the driver elements in front projection and RPTVs), as well as all the various processing circuits, focusing more on exactly matching the HDTV resolutions, plus the studio master resolution of 1080p which is already starting to appear in some new sets such as the Sharp LCDs

Of course an enthusiast will get frustrated by the fact that a "fixed pixel" display panel's resolution doesn't match any given signal. He wants to drive the display at it's native resolution to keep the display's scaler from having to do anything, and he'd prefer that NO scaling was done anywhere. Some displays, however, won't even take their "native" resolution as a valid input signal on all inputs, and may have trouble with how black is represented on digital inputs if a non-HDTV resolution is used. And even if the display will take that, he'll need an external scaler to get all the various OTHER signals to that resolution.

That is, if the fixed pixel display happened to match exactly either of the HDTV resolutions, it would STILL need scaling for standard-def TV and for the other HDTV resolution.

Finally, keep in mind that not all "720" style or "1080" style resolutions are the same when it comes to building these fixed pixel panels. Even if the panel is optimized for 1080i it's HORIZONTAL resolution may vary compared to another such TV. This gets into the whole idea of square vs. non-square pixels. This is way too complicated to get into here.

What it really all boils down to is that you need a good scaler SOMEWHERE, and you need to evaluate your potential display purchase at the different resolutions you intend to watch.
--Bob

Instead of build panels for consumer television and computer technology, why not build one panel that's big enough for both and use the necessary surface area.

For example, on a 768 panel, why didn't they just use 1280x720 rows and leave the outer rim unlit/unused?

Wouldn't this have also eliminated the need for odd scaling?

(Let me guess -- the marketing guys wanted to be able to say their TV had greater resolution, right?)

gp

Well I suppose that might be a factor, but the biggest reason is that since you've got a computer resolution panel in there anyway, you might as well offer the owner a computer input so he can use the display as a monitor.

And thus you don't want to mask down the panel.

Really the folks in this forum are way more concerned about scalers and their effect than the average HDTV consumer. To most people a scaler is simply part off the mysterious stuff inside the TV that "just works". It's all part and parcel of whether one TV looks better than another, but details such as real contrast ratio, and color depth (number of bits of internal color processing) are likely to be of greater impact than matching native resolutions.

Most of the things newbies complain about as scaler problems are really just artifacts in the original signal (such as cable or satellite digital compression artifacts) made much more visible due to watching a larger screen on a more precise display.
--Bob

Man WoW!, this post (thanks Bob) answers a lot of questions. It really should be made in a sticky in other forum topics too.

Bob,

I'm buying my first HDTV --- (CRT based) Mitsubishi WS-65315.

Would you think I would benefit from a upscaling DVD player, or will this TV do it well by itself?

Thanks.

DavidHir,
I'm not familiar with that Mits so I can't really answer that. In general the Mitsubishi TVs have a fine reputation.

However most CRT-based HDTV ready TVs will only attempt to convert normal DVD player signals (480i or 480p) to their EDTV style display -- usually 540p. On the other hand if you feed such a TV a 1080i signal from an upscaling player (or HDTV receiver) it will display it at 1080i.

Because the set is built to handle the kind of bandwidth involved in a 1080i signal, it's 540p image will likely be superior to the same resolution on a non-HDTV ready TV which means that if your 1080i or 540p signal is actually just an upscaled 480i signal (as from a DVD disc) you may not see much difference between the 1080i version of that signal and the 540p version. The difference between analog (S-video or component) and digital (HDMI or DVI) cabling may be more significant.

Of course when fed a TRUE 1080i signal as from your HDTV receiver, the TV's 1080i image will look its best. That's most likely what it has been optimized to show.

Again the data on the DVD disc is only 480i, so which signal looks better depends on how good the TV is in creating the 540p signal, or how good the player is in generating the 1080i signal plus whatever the TV does differently when fed a 480i or 480p signal from the DVD player (usually via analog cables) compared to a 1080i signal (possibly via digital cables). Some of these CRT sets look really really good when showing their 540p signal as long as the set is properly adjusted for edge to edge image geometry, color convergence, beam focus, and the basic whites/blacks/colors/sharpness levels for the signal from a given player on a given choice of cabling. Other such TVs put more filtering on low res signals and look their best only when fed a high quality, high res signal.

The folks over in the appropriate TV forum here will likely have a lot more experience with your particular set and any quirks it has when used with different types off source signals. For example, many TVs have different degrees of "overscan" (cropping off the edges of the image) or different limits on user controls such as for stretch/zoom when fed low res vs. high res signals. There might even be someone there who knows if your particular set has a reputation for doing good things with a low res signal, or if it is one of those TVs that filters the heck out off it with no way to turn that off.

The best upscaling DVD players ($1000 and up) are exceptionally good at what they do, and so I'd think a 1080i digital signal from one of those would look quite good on your TV. But the only way to know whether the difference is something that YOU can see is to try it. The less expensive upscaling players are often much better than the current crop of non-upscaling, progressive players so even a less expensive upscaling player *MIGHT* be worth the money.

Again, there is no easy answer here. Start from how much you are willing to spend. Pick a short list of candidate players from the discussions here and try them. If possible, borrow or buy on evaluation, a more expensive player and see if you, personally, can see any improvement over the less expensive player you like best.

When doing this, it is best to take the time to get familiar with how to use a calibration DVD. If the basic levels are set incorrectly on your TV, particularly if you have left them at the factory default "torch" mode settings, no DVD player is going to look great. You also need to have the patience to watch the same scenes in your favorite movies over and over and over again when trying the different combinations. If necessary, buy or borrow a cheap DVD player just to get used to the idea of calibrating your TV for a new player. Then take that experience with you as you look at the players you REALLY want.
--Bob

Thanks, Bob. I'm just growing frustrated as I don't know what to choose. I feel the more I read the more confused I get. But, I'll get it figured out. I'm now hearing the DVI inputs are working right on some models of Mits!

I will get the tv ISF'd and I already have Avia --- these things are crucial to me.

Great post! You just saved me from wasting money on a progressive player. My new JVC D-ILA seems to be doing a very good job upscaling on its own. The Sony DVP-S7700 is doing a good job with DVDs. I believe I'll wait for the new video disc war to play out now.

Man it's so hard to exhibit some patience and wait for HD-DVD and BLU Ray. I mean I'd hate to drop 1,400 on an AV51 only to see it be old technology possibly 1 year later. You could cheap out and get a cheap upscaler for 300.00 or less, but I think you also may be throwing money away for minimal improvement in PQ.

I would like to thank Bob Pariseau for sharing knowledge in this matter.

Thanks again,

Blackie:) :)

Wow, what a fantastic thread. Thanks again Bob.

Bob Pariseau,
As a newbie, not sure I completely understand your very informative threads here. I have a Pio Elite Pro 800 plasma TV, which has one hi-def input. My Rogers PVR is connected to that. I just bought a Denon 2910 DVD player which has DVI and HDMI outputs (which I can't use, right?). If I connect it to the TV via S-video, whether directly or thru my Marantz 5300 rcvr, does that mean I don't get any benefit from the player's upscaling, or even progressive, capabilities? It sounds better than my old nonprogressive JVC, but the image ain't knocking me out so far. Any help much appreciated.

If your TV has a digital input (DVI/HDMI), I would connect the DVD player to the TV using that connection. This is the only way you will be able to use the upconverting/scaling feature of your DVD player.

As I understand it, upscaling the Component video output is prohibited due to the possibility of piracy. There is some encryption going on when you connect digitally (via the HDMI).

Experts will be able to describe this better but I think this is the gist of it.

Good luck.

I'm trying to understand the math involved with making a dvd:

What fraction of the original raw data that is captured by a 1920X1080 24P camera that actually winds up on a dvd?

How much of a loss in pixel information is there in converting 1920X1080P to 480i?

How many fold does mpeg2 compress the 480i data?

Originally posted by gblunt99
Bob Pariseau,
As a newbie, not sure I completely understand your very informative threads here. I have a Pio Elite Pro 800 plasma TV, which has one hi-def input. My Rogers PVR is connected to that. I just bought a Denon 2910 DVD player which has DVI and HDMI outputs (which I can't use, right?). If I connect it to the TV via S-video, whether directly or thru my Marantz 5300 rcvr, does that mean I don't get any benefit from the player's upscaling, or even progressive, capabilities? It sounds better than my old nonprogressive JVC, but the image ain't knocking me out so far. Any help much appreciated.

You did not indicate the type of hi-def input your Elite TV has. If it is component, the only benefit to your new player will be the progressive mode. That's because upscaling is only available via HDMI/DVI. Basically, there aren't any (many) DVD players that upscale over component. I think the Zenith 318 did, but you'd have to find a used one now. Studios don't want hi-def coming out your component connection -- because they believe it will be easier to copy (This is a different argument/animal).

If the input is DVI/HDMI, you can buy a device switcher that will allow you to hook up both the PVR and DVD to the same input. This will allow your TV to "see" the higher resolutions being provided.

S-Video (and composite) inputs can not process hi-def material. Therefore, an upscaling player will not look better (through S-Video) than any other player. (The only possible difference will be due to quality/compatibility).

Thanks for the replies, fellas. Although I'm a little depressed now at having spent $1000 CAD on a player that isn't going to look much better than my $400. I just A & B'd them, and the sound is definitely better on the Denon. The picture (via S cable; my Pio has only one component input and no DVI or HDMI) is slightly better: more detail in the blacks, colours in general a little less lurid. I thought about possibly just connecting it via component each time I play a DVD, but I'd have to go into the TVs setup menu every time to tell it what the source is. Bummer.

I hope this is appropriate to ask here.. I am interested in connecting a pc to an HDTV to play DVDs and display photos. All the discussions of scaling and converting seem to apply to players.

What problems would I expect with a DVD drive in a PC? Can the video card be set to the native resolution which would seem to take care of the scaling?

Can anyone recommend a DVD drive and video card that you have used or seen that would handle photos and DVDs?

Thanks in advance and wish all a happy new year!

I am thinking of purchasing a dvd player with an hdmi output. I own a Toshiba 34hf84 crt direct view tv. Though the set seems to be known for geometric issues (I understand that is a recurring crt problem), my sets geometry seems to be fine. It has been a wonderful set. I'm currently using a very cheap Toshiba DVD player via componnent output. I replaced the tv and player at the same time. Naturally, with a far superior tv, my dvds look great to me. I have 3 questions.
1) Given my TV, would I benifit from going hdmi?
2) I may have misunderstood, but most of your article seemed like proper matching was an issue. Given that, would I be better of with a Toshiba dvd player such as the 5970?
3) I have the option of setting my TV to 1080i or 540p. Which way would you reccomend for current or future hdmi player?
Thanks

txstymie,
There's a whole forum here dedicated to folks who want to use their computers to drive home theater setups. Check out the "Home Theater Computer" forum, just under Video Processors in the list of forums, and you'll find lots of help as well as specific hardware recommendations.

The short answer is that if you like fiddling with computers -- changing hardware and tweaking settings -- then you can get great results. If you DON'T like such fiddling, then regular DVD players are likely your best bet.
--Bob

alalk,
First there's no good reason to stick with the same manufacturer -- i.e., no good reason to prefer a Toshiba DVD player just because you happen to own a Toshiba TV. Your TV won't know what's generating the video signal at the other end of that cable and the player won't do anything especially wonderful just because the TV it is connected to bears the same brand name. Buy the best player you can afford regardless of brand name and it will work just fine with your TV.

If you buy an up-scaling DVD player then you will likely HAVE TO use the HDMI input to take advantage of it. With the exception of a couple very unusual players, all the upscaling players require a digital connection for their high-res signals (since that's how they enforce copy protection). That is, if you connect such a player via component, analog video cables it will only send at best a "progressive" 480p signal -- in which case why pay for the up-scaling feature?

I think the odds are reasonably good that if you connect up a good up-scaling player via HDMI at 1080i you will see a noticeable improvement over what you could get with a good "progressive" player sending 480p via component cables (which your TV will display as 540p). This would be due to a combination of the advantages of the digital connection and the fact that your HDTV-ready TV is likely optimized to look it's best when fed a 1080i HDTV signal -- e.g., when folks are evaluating it in stores.
--Bob

Thanks Bob,
Two more quick ones.
1) Ant recommendations in 2-250 dollar area (cable included)?
2) Everyone seems to be talking about new crop of up-converting players due to come out. Should I wait?

alalk,
I don't have enough experience with the sub $250 players to give any useful recommendations. The folks here have recently been talking up new units from Zenith, Sony and Panasonic.

Unless you want to hold out for true High-Def DVD players due out at the end of 2005 or possibly 2006, as well as the eventual release of new discs for such format, there's no particular news around the corner in "upscaling" players for conventional DVDs. [If that sentence made no sense to you, re-read the last portion of my "primer" post at the top of this thread.]

At any given point in time you will find older players (6 to 9 months old perhaps) which have a solid track record, new players (a couple months old) with lots of buzz, a few known problems, and a limited track record, and hype regarding the next players about to be released. In general, unless you are interested in the very top end of the DVD player market, there is likely nothing in the hype worth waiting for. So your choice is to buy a player with a good track record that might be getting a little bit long in the tooth or a new player that has features you like but which may also have a few problems you don't know about yet.

Whatever you buy, and whenever you buy it, within 6 months you will likely be tempted to upgrade to a new unit. Indeed, that's what DVD player marketing people get paid to make happen. But realistically, if you make a good choice today, you should be able to enjoy it for at least a couple years before there's any real reason to think about replacing it.
--Bob

thanks bob

Something I don't think I've seen mentioned in this thread is colorspace conversion, which regrettably confuses things for many newbies & other people, including me. If you buy an "upconverting" DVD player that incorrectly deals with this, you will get bad colors. The new Sony DVD player with HDMI has this issue, for example. The older Zenith 318 that does component upconversion also has the issue. You may not like the idea of trading off a perceived higher resolution for inaccurate color (green tends to be messed up most).

Check out other threads for details. Bottom line, MPEG2 is encoded in YCrCb, not RGB space. The coefficients for deriving actual displayed colors from the YCrCb signal are NOT the same between standard def NTSC that DVDs are encoded in versus high def ATSC signals. Your TV will see that 720p or 1080i signal and automatically engage its HD color matrix to decode the YCrCb signal--but the player might have sent it in the SD colorspace, so the derived RGB values will be wrong and the colors come out looking off. It's mathematically trivial to interconvert, but many DVD players are not yet designed to do this or their firmware hasn't been updated. Hopefully this will disappear in all production models with time.

This is a good example of the snake oil that the originating poster of this thread mentioned in his first post. Firms rushed their players to market so they could have *** UPCONVERSION *** without even remembering basic linear algebra, and the proper conversion of 3-component vectors from one basis space to another.... It has worked, as many people love their upconverting players even with the color errors (which may be less noticeable, really, than bad deinterlacing) introduced by the process.

ranger999,
Yes, this is important. Just as with the original "progressive" players, it will take some time for testers/reviewers to twig off on just how screwed up some of the "upscaling" players can be -- i.e., what's really important to test for and report.

However, let's not get too alarmist. There are upscaling players that have nimbly avoided falling into any of these engineering traps. They handle black-white range and color fidelity just fine whether connected DVI to DVI, HDMI to HDMI, or HDMI to DVI at high resolution. The players that make mistakes here have "bugs", some of which are fixable by easy firmware upgrades available to those in the know -- e.g., people who read this forum.

It is also the case that some of the reported player problems are, sadly, really due to the technology having passed by some TVs out there. If you have a display with a DVI input that is stuck in "PC-style" digital encoding you are screwed. Some players will put a band-aid on this by switching their output to PC-style encoding, but at the expense of throwing away the protective "blacker than black" and "high white" data in the digital video stream.

Similarly if you have a display with an HDMI input that assumes HDTV style colors are the only colors that can come in at high resolution, then you are also screwed. The new upscaling players provide high resolution DVD images using SDTV colors and all new displays should be able to switch between the two color sets according to which source you are viewing.

And all of this is complicated further by the fact that the color space actually used by the DVD producer just MIGHT be the HDTV form, and that the info on the DVD which tells which color space was used is OPTIONAL and generally not filled in for current DVD transfers.

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

So what's a poor consumer to do?

First, buy a TV with either an HDMI input or with a DVI input that specifically supports "DVD players" or "set top boxes" or "video sources" as opposed to "computer" or "PC sources". Since DVI was originally a cabling for computers, better/newer TVs will usually make this user selectable in their menus. But older TVs may have been designed assuming only computers would use the DVI input and will offer no setting for "video" sources. Any TV with an HDMI input is already correct in this regard, since the HDMI standard is designed for "video" sources.

Second, if your TV has an HDMI input, make sure it can switch between HDTV and SDTV style colors on that input regardless of the resolution of the input signal. Thus you will get correct colors whether you use that HDMI input with an external HDTV receiver or with an upscaling DVD player. For convenience this setting should be part of a setup "memory" in the TV so that when you switch the TV's settings for blacks/whites/colors/sharpness between your HDTV receiver and your DVD player sources, the color space setting will also change as well.

Third, buy a DVD player that will properly pass "blacker than black" video data via its digital video output. The testing on the Secrets web site has started to report this. Note that there are three possible tests here for potential bugs. I.e., does the player do it right when connected DVI to DVI, HDMI to HDMI, and also HDMI to DVI. It is possible that a menu adjustment may be needed in any given player to make this work, but it really should work correctly by default in all three cases.

Finally, buy a DVD player that uses SDTV color space even when outputting high resolution over it's digital video connections. Again, you'll likely have to trust to testers or reports on this forum to know what's what here. Ideally the player should (1) look for the info on the DVD that says the DVD color space is SDTV style or HDTV style, (2) follow that if it is present, but (3) default to SDTV style if it isn't present. But simply getting the default case of SDTV style correct is probably good enough. For those familiar with calibration DVDs this means no significant green push or depression on the color decoder test chart when Color and Tint are set properly to dial in blue -- and specifically at high resolution via the digital outputs. Remember that if you are connecting to an HDMI input on your TV then that input must be set to expect SDTV style colors from the upscaling DVD player -- DVI inputs will have no such adjustment since they just take whatever the player hands them.

The good news is that most newer TVs, displays and projectors will properly handle their end, and as for upscaling players there are certainly examples out there of players without problems in this regard, such as the Pioneer Elite 59avi. However there are older TVs and projectors which will be problematic, and there are certainly bugs in some new DVD players in this regard.
--Bob

Hi Bob,

Great write-up you have here, especially for newbies like me. A few general questions for you, if I may.

1) Although this may be hard to state, how much does a good DVD player affect PQ compared to a good HDTV? In other words, if I have an average HDTV and an average DVD player, will I get a better PQ from getting a better TV or a better DVD player?

2) On a related note, I was surprised when the guys on the Avia DVD said that the PQ and sound isn't much different between high-end or low-end DVD players. I have the Toshiba SD-5970 (which I watch upconverted to the native 1080i of my TV), but I plan on returning it for many of the quality workmanship issues that others have mentioned on the forum. I'm just wondering if dropping down more money for maybe one of the Panasonic or Sony upconversion players is really going to give me a better PQ (I have the Toshiba 30HF84, which I'm also considering returning, but the TV will be direct view in either case).

3) I see some here claiming "HD-like quality" from DVDs, but I assume this is very DVD dependent? I would think there are some movies (particularly older ones) that will likely look "grainy" on even the most high-end equipment. On the other hand, CG films (like anything by Pixar) will probably look good on just about any quality HDTV. I've been testing my current set-up with "The Fifth Element" (not the superbit version). I've noticed there are some scenes where it seems I can make out almost every wrinkle and blemish on Bruce Willis' face, and then on the next scene everything seems a little grainy. I'm trying to convince myself that this is the quality of the DVD and not the player or the TV, but I'm admitedly having my doubts...I just have no way to prove it. Both the TV (my first HDTV - actually my first TV period...just never bothered to get one before) and DVD player are new, so I have nothing to compare it to, but I just thought DVDs overall would look better than they do.

Thanks for any insight you can provide,

avmem

avmem,
First the quality of the image will depend upon the quality of the movie and its transfer to DVD. The better, i.e., more precise, your TV and player, the more likely they will be unforgiving in their ability to show off crappy source content. Big screen HDTV owners are already familiar with this problem when viewing SDTV programs -- particularly digital SDTV that is also over compressed by cable or satellite operators. Some movies have flaws in the original filming, others have flaws due to age related deterioration in the film stock, and the process of transferring any film to DVD brings in its own problems -- particularly if too much inter-frame compression was used to squeeze the film into a smaller space in order to cram "extras" on the DVD, or simply because the transfer editors were careless. Such errors can indeed crop up on a scene by scene basis.

Simply put, good hardware is not going to make a bad movie look better, and in fact, may make the errors in the movie even more distracting.

As for whether to put your money into a better player or TV here are a few thoughts:

1) Once artifacts have been put into the video stream, the best hardware downstream is going to be hard pressed to remove or conceal them. If you buy a cheap player and ask it to do extra processing such as de-interlacing or upscaling, it will likely make mistakes. The lower the quality of the player, the better off you will likely be setting it to just pass a 480i signal from the DVD (or at most a 480p "progressive signal) and letting the TV do the rest of the work.

2) The extra money you'll need to spend to go from an average player to the "best" player is less then the extra money you'll need to spend to go from an average HDTV to the "best" HDTV.

3) Even an average HDTV-ready TV is already built to handle higher bandwidth and resolution than is recorded on any DVD. However, a poorly engineered HDTV will likely show off the defects in its design no matter what you watch. For example a CRT-based TV with poor image geometry or color convergence, or an LCD panel with lousy black levels or bad motion blur, or a plasma panel with low color bit depth or bad motion processing in its pixel driver circuitry will all produce really annoying TV no matter how good your DVD player. And that will affect your normal and HD TV watching as well.

So if you like the HDTV you are seeing on your current TV then I'd recommend putting your money into a better DVD player. But if the HDTV on your current TV is annoying, then you should probably upgrade your TV first.

As for Avia, keep in mind that (1) the narration was recorded a few years ago, before there was really that much difference between the best and worst consumer DVD players (often the biggest difference was the choice of cabling), and (2) the point the Avia people are making is that even the best DVD player isn't going to look good until you dial in the proper calibration levels on your TV for it.
--Bob

Bob,
That was very helpful for understanding much of this gobbeldygook. Secrets of Home Theater does a good job of keeping tabs on the innards of DVD players, but where can I find a reliable comparison of the scalers built into different TVs? I'm trying to figure out if a fancy new upscaling DVD player with DVI will do much more for my Toshiba 30HF83 30" CRT than a popular 'plain old', lower end, progressive player will.

Your best bet is probably to check over in the CRT TV forum here. Scalers in TVs are tough to compare because they are so intricately connected to the other engineering choices made inside the TV such as the use of square vs. non-square pixels, actual native pixel resolution, and special processing needed to drive the pixels properly such as motion processing to get the timing right for pixel firing in a plasma panel. In the end, specs are probably less important than subjective reviews -- i.e., what looks good to the reviewer and to you.

Keep in mind that your HDTV-ready CRT likely has two "native" display formats: An EDTV format (likely 540p) for standard TV and and HDTV format (likely 1080i) for HDTV. So if you feed the TV a 480i or 480p signal from a DVD player it will likely scale it to no more than 540p, but if you feed it a 1080i signal from an upscaling player it will display it at 1080i without additional scaling.

So making the comparison is actually easier for you than for folks with fixed pixel displays that are always scaling whatever they receive to their native pixel count.
--Bob

Bob,
I'm new to everything in Hd. I have a Samsung DLP HLN467.I need a new dvd player. I have read your very informative posts and understand most of it. My question is with everything being equal (all dvd's being 480i),will a dvd player with dvi output to my dvi input on my tv produce a better picture? Is it worth the extra money to get a player with a dvi connection? Is it actually the dvi connection that is giving the better picture and not the upscaling?
Hope these questions are not to primitive,

camroc

camroc,
I don't think there's been enough testing of player/display combos to state definitively just how big a role the digital connection (like DVI) plays in this puzzle, but the available evidence points to it being pretty significant.

Most players with an HDMI or DVI output will also be upscaling players (i.e., you'll be paying for upscaling anyway) so you can connect it up via DVI and compare for yourself between having the player send out 480p or 720p for example. You'll get the benefits of the digital connection in either case and will simply be choosing between whether the player or DLP does a better job of scaling.
--Bob

Thanks Bob,

Excellent advice - I appreciate your thorough explanation. Since I'm planning on returning the DVD player anyway, I'll take that route and see how it goes.


creamy,

I don't know if this is helpful, but I have the 30HF84. I'm not sure if the scaler is any different in the 30HF84 than the 30HF83 - the only difference I know of is one has DVI and the other HDMI. I have this currently hooked up to a Toshiba SD-5970. Although this player isn't on anyones short list of upconverting DVD players (cheaply made, which is why I'll be returning it), I'm getting a nice picture out of it right now. Picture quality is rather subjective, but for me, the picture looks just a little crisper having the DVD player upconvert to the native 1080i then outputting 480p and letting the TV do the work. Of course, your opinion may be different...

avmem

Wow. Excellent write up Bob! Thanks for doing that.

With the recent announcement from CES of first titles for HD-DVD for Q4, I'm starting to think about my current, far too large, DVD collection and the upgrade potential in the near future.

For a really good DVD transfer (take one of the LOTR movies for example) I'm curious as to how much better it will look when released in an HD version? Yes better is very subjective. Obviously the source and how the film was originally filmed will play a huge part in the decision making process.

I just don't forsee that all titles will be worthwhile to replace with their HD counterparts and thus all us HD/DVD fanatics will be looking at each HD version of the movie on a case by case basis. Am I completely wrong in my thinking???

talman,
Not at all. There's plenty of room for shoddy production quality in any new "HD" transfers. And the new discs only need to be "just good enough" to get the buying frenzy going.

Then the studios can re-sell the same movies again later as higher quality, special edition transfers.

Meanwhile conventional DVD transfers can continue to be improved ala "Superbit".

The earliest hardware and the earliest "HD" discs are likely to be pretty good to get the buzz going (and also expensive enough to give an oil sheik pause), but then I fully expect a good year or so of serious corner cutting as companies rush products onto the shelves to try and rake in what product marketing guys call the "low hanging fruit" -- the easy sales, i.e., the folks that will buy just about anything if you use the right buzz words to describe it. Then quality will be further limited as companies race each other to the bottom of the price curve. Finally the market will stablize and higher quality will be a more important distinguishing factor, and at the price point mere mortals can afford.

That will be, oh, about 3 years after first release.

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

But heck, I remember the first CD players -- you know, the ones where everyone in the room had to sit still and not breathe hard or the pickup would skip? And people bought those -- for a bunch of dough -- and that's back when a dollar was worth, oh, a good 50 cents -- anyway more than it's worth today.
--Bob

Bob,
I'm still trying to understand the math in making a dvd. If the 1080 24p digital film master is around a 150 gigabytes and it gets converted to 480i which is 240P that should be a 4.5 fold reduction in the amount of data = 30 gigabytes. If mpeg2 compression is 30:1 then that should takes us down to around a gigabyte for a 2 hour movie. That sure leaves a lot of room for audio, trailers and games on a 8.5 gig disk. What is it that I'm missing here?

Chavel,
Every time I try to do stuff like this I end up missing or adding a factor of 2 somewhere but let me give it a shot.

First of all a dual layer, single sided DVD (8.5GByte capacity) has a nominal max capacity of 240 minutes of film. Now that's based on an average content bit rate of 4.7 Mb/s (i.e., roughly, 4.7Mbits/s x 60sec x 240min / 8bits per Byte is approx = 8.5 GBytes -- the difference being overhead data). The minimum recommended bit rate is only just below that at 4 Mb/s.

The MAXIMUM bit rate supported by the standard on the other hand is more than twice that much at 10.08 Mb/s. A dual-layer, single sided DVD recorded at the maximum bit rate would, therefore, allow slightly less than half the nominal capacity -- or only about 2 hours of film. The difference between the minimum and maximum bit rates is the degree to which the content producers crank up the inter-frame compression and the choices made regarding the data structure of each frame.

Now the 10.08 Mb/s rate is not all video. Some of it is control overhead. Discard that and you are down to 9.8 Mb/s. Some of it is audio tracks and subtitles. Assuming 3 Dolby digital streams (alternate languages) at 448Kb/s each, and 4 "sub picture" streams (subtitles) at 10Kb/s each the MAXIMUM video bit rate is 8.4 Mb/s.

[NOTE: The format supports up to 8 languages (or alternate multi-channel audio encoding formats), subtitles for up to 32 languages, alternate video streams (camera angles) for up to 9 streams, menus, and of course the ubiquitous "extras" all of which also take up space depending upon how the content producer decides he wants to divy up the available capacity. But the more of that stuff you put in, the less space you have for high quality recording of your primary video track.]

So let's assume you want to do the highest quality possible video on a single sided, dual layer, DVD with 3 audio streams and 4 subtitle streams. That means you will want to compress your video only so much as to get it to fit into that max video bit rate of 8.4 Mb/s.

Forget about the studio masters of the digitized film for a moment and concentrate on a 480i frame. Twenty-four times a second (i.e., the frame rate for film based content) you will need to record luminance and color data for 720 x 480 pixels. If you took a computer approach to this and did that in RGB at only 8 bits per color, that's 720 x 480 x 3 colors x 8 bits per color x 24 = 199Mb/s. To get that to fit into your available 8.4Mb/s you will need a net compression factor of 23.7. And that's the MINIMUM compression you'll need. Any additional compression damages the image further.

[NOTE: You may be wondering how the 24 fps film rate becomes the 30 fps video rate for your TV. Well that's done by the player as part of the DVD standard (whether or not the player also includes de-interlacing) in order to keep from having to store even MORE frames/sec on the DVD for it's most common use as a storage mechanism for films. This is achieved by duplicating certain, interlaced, half-frames (called "fields") in a regular cadence. Doing this is easy. What's hard is doing DE-interlacing properly in the presence of both film and video frame rate stuff coming off the DVD and thus maybe -- or maybe not -- in the presence of these periodically recurring, replicated "fields". Since films are sometimes edited with digital editing equipment that ends up spitting out video frame rate results, just because something is a movie doesn't mean that some scenes aren't coming off the DVD at video frame rates.]

That 23.7 compression factor is achieved through a combination of cutting corners on the amount of data in each frame and by MPEG2 digital compression, which takes advantage of the similarities in the image from frame to frame so as to send info only on the portions that are changing. The most important corner that is cut as regards each frame is that the color data is not really sent at the same pixel resolution as the luminance data, in accordance with choices that were made long ago as regards a standard, broadcast color TV signal.

So when you allow for the chintzy color signal, the additional compression you need to glom out of your MPEG2 encoder is a more modest level, say about 15x.

Now compression doesn't come for free. It is "lossy". The more compression you have to use the worse off the resulting image will be. And indeed at any given LEVEL of compression there are CHOICES the authoring tools get to make according to where in the image to focus the efforts of compression. Badly made choices result in visible artifacts. Nevertheless the studios are getting better and better at this.

OK, so this is all doable. But that means you are going to have only 2 hour capacity on the disc. Well by the time you add in MORE than 3 audio tracks, fancy animated menus, and all the desired "extras", the net result is that you have to crank up the MPEG2 compression higher to make it all fit -- which damages the video. And that's where the studios have a choice. Will people buy discs based more on a high quality transfer, or because there are DVD-ROM games added onto the disc?

As a final note, when comparing studio masters to a 480i signal, in addition to adjusting for the color sampling rate, keep in mind that a high vertical resolution also means a correspondingly high horizontal resolution. E.g., taking wide screen formats for an example, 540p is not the same bit rate as 1080i. In fact 720p is much closer to the bit rate of 1080i, which is why 720p and 1080i are the paired broadcast resolutions for HDTV -- i.e., they both consume about the same amount of frequency bandwidth licensed to any given broadcast TV station.
--Bob

Bob

A fantastic thread! Your posts are always very informative and easy to understand. Thank you.

Gary

Thank you for the informative reply. It sure is enough to put me in the Blu-Ray camp. So current dvd's are not only 480i but also a measly 256 colors.

Not quite Chavel. The color depth for the 480i format is actually pretty good. Not great but pretty good. What's limited is the spatial resolution for color information.
--Bob

Originally posted by Bob Pariseau
Now compression doesn't come for free. It is "lossy".

I'm going to be pedantic here, so feel free to ignore me. Bob is talking specifically about compression techniques used for audio, video, and images (mpeg, jpeg, divx, etc). There are lossless compression techiques as well but these are not suited to multimedia.

Quite correct. And there are some compression schemes that are lossless (i.e., completely reversible with perfect fidelity) up to a certain point and only become lossy beyond that point.

But as far as DVDs are concerned, the less compression used the better. As pointed out above, you have to use SOME compression no matter what you do or the bit rate will be higher than the DVD format can support. Ideally the content authors will be careful to use the absolute minimum compression.

Now compression is by no means the only area where DVD makers can screw up a transfer of film to DVD, but the other screwups tend to be mistakes whereas over-compressioin is, unfortunately, often done intentionally to cram other stuff onto the disc or to keep the content (movie plus extras) from spilling over to yet another disc.

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When the next generation, true high-defintion DVD formats are launched later this year, we'll all get to have fun finding the flaws in the new compression schemes used (and abused!) for those formats. MPEG4 will also start showing up in satellite TV systems sometime this year. Once again, there's a world of difference between what these new compression schemes can do if they are used with care and the damage they will produce if pushed too far.
--Bob

I just bought "Men In Black" on DVD. Disc 1 has widescreen --AND-- fullscreen versions on it. Does that mean there are two complete copies on that disk? (If not, how does that work)? (If so, why aren't the two copies on separate disks -- since there is a bonus second disk anyway)?

Also, I'm guessing that blank DVDs are pretty cheap -- especially when purchased in the quantities necessary to distribute movies. Is saving that extra 20 cents per copy really worth releasing a lower quality, higher- compressed product. (Compared to loading the bonus features on a second disk)?

Finally, I just bought my first (and possibly only) superbit DVD. I can see a small improvement in resolution -- but the bigger difference seems to be in color fidelity. Am I imagining things? (Vin Diesel's XXX on a 120" projection screen). I also purchased the Star Wars Trilogy and I was surprised how good they looked -- especially the original movie. Since each movie occupies one DVD, could they be near superbit quality without advertising this?

Discs that contain both widescreen and full screen versions of the movie do, indeed, contain two complete copies of the movie. Often this is done by doing SINGLE layer encoding on both sides of the disc -- since dual layer recording on both sides is apparently still a bit tricky. That means the nominal capacity for each side is about 2 hours and the capacity for the best quality recording is only about 1 hour. And thus both versions of the movie are likely compressed more than they could be if recorded on separate discs.

The alternative is to record a dual layer single sided disc with both copies included. One easy way to do this is to put the widescreen in one layer and the fullscreen in the other layer. The same capacity and compression issues arise as with a single layer two sided disc, but of course you don't have to flip the disc over to get to the right content -- a menu selection alone will do the trick.

There IS a special formatting mechanism in the DVD standard to record a wide-screen movie along with pan and scan instructions telling the player which PORTION of that widescreen image to show on a 4:3 display for any given scene. Such a recording would only have one copy of the movie (plus a small amount of space taken up by the instructions). But this is a format which never really took off since producers want to have more control over creating the fullscreen version than the pan and scan DVD format allows.

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

Superbit recordings are often done with extra care regarding the transfer, and so it would not surprise me to find that among other things they had taken a look at improving the color balance compared to the original DVD release. The reduced compression (higher bit rate) on the Superbit DVD should not, in and of itself, affect the color balance of the movie.

But yes, there are "standard" studio DVD transfers that are just as good as any Superbit DVD.

Many players (for example the Pioneer 59avi) give you the ability to see the actual bit transfer rate as you move through different portions of the movie. That's an easy way to see how any given movie stacks up in terms of compression. Keep in mind, however, that some scenes naturally compress to a greater degree without visible artifacts. Producers take advantage of that to keep from having to over-compress other, more difficult scenes. It is the AVERAGE bit rate that is usually meaningful here. But still, if you see problems in a scene and also see a low bit rate, then the odds are the studio wasn't careful enough in deciding how much to compress that scene.
--Bob

This was by far, the best informative writing in relation to the HD world I have read yet.

What a great thread...thank you so much for all the information...

what I find amazing is that I can easily get better quality if they would spend the couple of extra cents and put the movie on multiple disks...

jeez...give me the option...I have no problem changing disks if it means better PQ...

Thanks Bob,

Absolutely an incredible workof postings. I'm a newbee in the market and you've clarified so many questions I had.

Anubys,
They ARE giving you the option -- now. For a mere 50 or 80% price premium you can buy a second copy of some films transferred to DVD ala "superbit". And indeed those transfers have NO extras -- no comment tracks from the producers, no still picture galleries, no "here's how we made the film" documentaries, no games -- and sometimes even then they end up having to split the movie onto two discs. All that higher price is almost pure profit.

The bottom line, however, is that hot flicks sell well even in compressed form, and most buyers assume that the version with the most extras on it must be the best version.

So the studios try to get your money three times for the same movie. The original release is rushed out on 1 disc, with some extras and probably too much compression. Then the special edition comes out with even MORE extras -- usually requiring a second disc for all those -- and may or may not have a better transfer on the primary disc. Finally they can put out the high quality transfer version for finicky collectors which MIGHT really be a better transfer than on the special edition version.

Pretty soon they'll be doing the same thing with new, HD discs. The boys in Building "C" are going to need bigger wallets.

Now there are some studios, under pressure from directors and producers, who really do try to put out quality stuff from the get go. And indeed some "extras" really are fun to have. But you should look for transfers that have widescreen and fullscreen on different discs and have a separate disc for just about everything "extra" except for alternate commentary audio tracks.
--Bob

Excellent...now I know what to look for...This is what I got with The Lord of the Rings (but I didn't look for it, it was just what Costco had)...I never look at the extras...

I finally got a DVI switch so I will now be able to use my Bravo D1's upconversion capabilities (I know, I know...you do what you can!)

Thanks again, Bob! :)

Hear's another trick. Many DVDs will include in the fine text on the back label details about how they are put together over and above whether there's a separate disc for widescreen vs. fullscreen and for extras.

Typically you will be able to find the running time of the feature for instance. And if you keep squinting, you may find out whether the DVD(s) are double or single sided and whether they are dual or single layer. The most common format you will find used is a single sided, dual layer DVD (the other side of which has the movie label printed on it).

If the feature length is close to 2 hours and the DVD is single layer and recorded on only one side (of one disc), then you can be sure it is over compressed. If it is a dual layer DVD then you have a fighting chance depending upon how many audio tracks there are and what extras are incorporated on the primary DVD disc.

Now just because they used a disc with enough capacity is no guarantee they actually USED that capacity wisely to keep compression down. But at least you have a fighting chance.

Also there's a whole forum here devoted to people who like to chat about the quality of particular DVD transfers.

Keep in mind that some movies naturally have low data rates, such as black and white movies with a single, mono sound track. Widescreen and fullscreen movies will tend to have the same data rates because the widescreen movie is anamorphically distorted to fit into a 4:3 shape before it is recorded on the DVD (distortion which your player automatically removes to recreate the 16:9 frames).

Now I should stress again, you shouldn't angst TOO much about this compression stuff. The difference between an average, combined data rate of 8.9 Mb/s and 8.0 Mb/s is likely not going to be visible to most people for example. The format is supposed to be designed so that even the maximum compression SHOULD yield a very good quality movie if due care is taken -- but note that over-compressed transfers are usually slapped together shoddily in other ways as well. And there are many other things the studios can do to screw up transfers such as screwing up the black/white/colors balance, bad chapter transitions and layer changes (yes the disc producers have a major role to play in minimizing layer change delays), poorly used or simply incorrect flags that make de-interlacing tougher instead of easier, and screwed up multi-channel sound tracks.

Consider, for example, that a studio might be concerned that MOST TVs out there in people's homes are already screwed up -- being left in the manufacturer's default "torch" mode settings. So should you bias colors and such on your new DVD transfer for the knowledgeable few who have good TVs and have set them up properly? Or should you adjust the transfer to look as good as it can (which ain't great by any measure) on the lowest, and overly common, denominator TVs out there? Such are the problems facing the poor DVD marketing guys. Guess which one they pick for early, mass release of hot flicks? In particular, this is why some of the fullscreen releases look so bad.
--Bob

Bob,
A few questions here;-

(1) You mention dvd`s encoded onto the disc at 480i(region 1)0But what about region 2 discs at 576i(pal)-are they encoded at 576i or encoded at 480i still?

(2) If money was no object what would be the best dvd player to have?

(3) Would the best scenario be to combine a top quality scaler & dvd in one package-like Faroudja did?

(4) What would give the better pic for dvd (all source and cables/display being equal.)

SDI at 576i into a scaler output to a crt via RGB at 1080i or 576i via component input to a scaler -output to a crt via RGB at 720p?

Thanks-great thread!;)

Good catch, Vincent! Call me a typically provincial American.

Yes, PAL DVDs are encoded at 720x576i in a 4:3 aspect ratio or as a 16:9 aspect ratio anamorphically compressed into 4:3. Video based content is recorded at 25 frames/sec. Film based content is recorded at 24 frames/sec but is played back at 25 frames/sec without further adjustment (i.e., a given film recorded on a PAL DVD will play back in only 96% of the time it takes the same film to play back on an NTSC DVD). From the video point of view the difference is small enough to be negligible, but PAL DVD makers have to pitch correct the audio of any film before it is recorded on the DVD so that the audio will sound right when played back at the slightly faster speed.

As far as compression requirements, since the film is actually placed on the DVD at 24 fps, the frame rate difference doesn't alter the space needed for the film -- but the increased vertical resolution of the PAL frame makes a significant difference. A PAL film will need more compression to fit into the same space or will take more space to match the same quality of an NTSC film. I.e., PAL films need a higher bit rate to match the quality of the equivalent NTSC film.

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There's no easy answer to the "best" player question because it depends upon too many different things, even disregarding cost. For example, do you want to play the various exotic audio formats (DVD-Audio and SACD) as well? Do you have a display which will accept a 1 to 1 pixel match as it's input signal -- in which case an external scaler might be a big win? Are you willing to wait until the next generation, high-definition DVD players get launched later this year?

I use a Pioneer Elite DV-59avi, and I'm quite happy with it, but it is by no means "perfect" and there are certainly players available out there that cost much much more. The about to be released Denon 5910 has drawn a lot of attention recently for incorporating a professional video scaling solution as well as a de-interlacing solution from one of the best known external scaler companies.

Meanwhile scalers in TVs, and external scalers to go between players and TVs also keep getting better.

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The advantage of the all in one solution SHOULD be tighter integration and an easier to use user interface, particularly as regards setup options. Unfortunately some popular integrated solutions are actually a step backwards. Many DVD manufacturers have gotten bit by choosing a popular chip for driving HDMI outputs for instance, only to discover after the fact that they needed to adjust their firmware to handle a bug in that particular chip.

I'm afraid there's no easy way for a consumer to know for sure which solution is better. High quality testing, as in the Secrets of Home Theater web site's DVD player benchmarks are a good starting point. But in the end you are going to have to sit down with a candidate player and judge for yourself.

It is unfortunately true that players are changing fast enough that (1) reviews are often out of date by the time you see them due to firmware upgrades or model changes, and (2) the reviewers are having a hard time keeping up with new mistakes player manufacturers are making. Things are being found broken that folks have not been testing for because they've always worked in previous designs or because the broken feature involves some new design element.

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Passing digital 480i or 576i via SDI to a good external scaler will almost certainly give you a better result than passing the same signal via analog, component video cabling due to filtering and additional analog/digital conversion that exists in the component version.

Ideally the output resolution from the scaler should exactly match the "native" resolution of the display so that the display's scaler has no work to do. The connection from the scaler to the display should also be digital if possible.
--Bob

Bob,

I have to admit that this is THE MOST informative thread I have ever read in regards to anything relating to my home theater. The next closest being the Keohi site that helped me tweak my old Toshiba TN61X81 the best that I could outside of an ISF calibration. (Disabling SVM, Convergence Grids, AVIA disc... you name it.) I thought I was da man.

I will also admit that all my plans to buy have gone to the waste side. I do know that I will be selling this old CRT. It only accepts analog, component inputs. I have learned that I can make out with a decently priced HDTV if I feed it the right signal the right way. This I thank you TREMENDOUSLY for. I was about to make all the wrong choices.

Now, feeding this new, probably DLP, HDTV set is another thing. I thought I had settled on the Denon 3910 and maybe a SDI modification. Then, I see this 5910, but it will cost more than my HDTV set. Now, I'm back to finding a decent DVD player and the iScan HD+. I have the JVC XV-721BK. It has a 7-disc carousel and progressive output.

Anyways, does anyone make a nice carousel DVD nowadays?

Are you saying Bob that a 480i version on dvd would have a better picture then the 576i PAL equivalent?

Is there only 480 lines of "true" information in a 576 line PAL disc?

BadBOy2K,
I haven't been following the DVD changer discussions here closely enough, but it appears the changers are kind of lagging behind the single disc players. For example, I don't believe anyone in the various threads on this has yet found a DVD changer that includes a digital video output.

DVD changers are a bit of a strange bird anyway (compared to CD changers), since you can't just set them and let them work on their own. Each time they reach a new disc you'll have to get involved and deal with startup menu screens.
--Bob

Vincent,
No, PAL has a true 576 active lines of data just as you thought.

Now when it comes to regular TV (either in broadcast or as recorded on a DVD), the extra vertical resolution of PAL plays off against it's slower refresh rate: NTSC at 480 lines renewed 30 times a second vs. PAL at 576 lines renewed 25 times a second. Both choices have their advocates, but if you do the math, 720x480x30 and 720x576x25 are both the same amount of data per second. [In reality NTSC is slightly less since its true frame rate is really 29.97 fps for technical reasons.]

However for films recorded on DVD the frame rate for both is set at the film frame rate of 24 fps. So now the uncompressed PAL data rate is higher than the NTSC rate due to the extra lines of vertical resolution in PAL. When playing back films, both styles have to be adjusted back to video frame rates. NTSC players "create" a 30fps video stream for playback from that 24fps data by periodically duplicating "fields" (interlaced half-frames). PAL players just play the 24fps data back slightly too fast to generate their required 25 fps video stream. So the data rate for PLAYBACK from a PAL DVD is increased by 4% just to meet the video output stream requirements and with no corresponding increase in image quality. This last effect for PAL can be considered negligible as long as the recorded data on the DVD is not bumping up against the maximum data rate the format can support.

So the upshot is that this should give PAL an advantage since each frame is denser and there's no need to interpolate duplicated fields. But you have a trade off because the PAL signal generally requires higher compression to fit in the same space on the DVD. The question is whether the gains from the slight increase in vertical resolution and easier adjustment to video frame rates are greater than the losses from higher compression.

Unfortunately the compression defects usually dominate. And thus the conclusion that you need a slightly higher bit rate off of the DVD (i.e., less compression) to get the SAME quality from a PAL version of a film compared to an NTSC version.

If you ponder this, you'll see it is a good example of why DVD makers should strive to use the least compression possible when recording any given film to DVD. Above some threshold level of compression, compression related artifacts will tend to overwhelm good choices they make elsewhere in the transfer process.
--Bob

Thanks Bob,thats really interesting..I wont feel so bad putting my hand in my pocket for Region 1 titles now! :-)

Vincent,
Before you do that, keep in mind that your PAL TV may not do as good a job showing NTSC video as a US, NTSC TV. That's because your TV is connected to 50Hz power and its primary design focus is PAL. Now it's been a while since I looked into any PAL TVs but there was, at one point, a design philosophy for PAL TVs that said if you are going to feed it NTSC we'll just do the bare minimum to make the image watchable. So before you go buying a ton of NTSC DVDs, you should double check that your TV isn't going to frustrate you.

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EDITED TO ADD: Of course the alternative is to get a DVD player that will convert NTSC DVDs to PAL video output format. However the poor quality of the NTSC to PAL conversion in any given player may over-ride any quality gains you were hoping to get from a particular NTSC disc.
--Bob

Not quite Chavel. The color depth for the 480i format is actually pretty good. Not great but pretty good. What's limited is the spatial resolution for color information.
_____________________________________

What is the signal that comes out of the telecine process? Assuming a 1920X1080 24P 16 bit = 3 Gb/sec goes in. I'd like to know how much the 480i signal suffers before it goes through mepeg2 compression.

Chavel,
Simply put, the video stream that goes into the MPEG2 encoder for digitized film is 24 frames per second of luminance info at 720x480x8bits and two channels of color difference info at half that vertical and horizontal resolution or 2channelsx360x240x8bits per channel.

The combined bit rate is then 24x(720x480x8 + 2x360x240x8) = 99.5Mb/s

...presuming I haven't done my usual trick of screwing up a factor of 2 somewhere.
--Bob

Not as simple as I thought. Multiple data streams and interlacing really complicate things. I didn't get my calculation right. I wrongly thought that the video stream for a 1920X1080 24P 16 bit color would be multiplied by 2^16 or 65,500 colors. I did read that 1080P was 3 Gb/second twice that of 1080i and 720P though. So I'm not sure if there is a compression factor of 30 (3Gb/s/99.5 Mb/s) in going from the digital master to the video stream prior to mpeg2 encoding. Thanks for the education.

Bob,

First, I'm going to add my applause to the rest of us who are grateful for the time and effort you obviously put out in giving us the benefit of your knowledge and experience. Thanks.

I have a problem that I don’t know the proper name for, much less a solution. I have recently stepped up from an old tv to a Pioneer Pro-910HD plasma. I love almost everything about it, and am not at all bothered by the few quibbles I've read about, like concerns about black levels. So far, I mostly watch SD broadcasts over D*TV and some off-the-air HD broadcasts. I expect to move up to HD satellite soon. I currently have a Sony DVD player, but just ordered a Pioneer DV59avi, due in no small part to the information I gathered in this forum. (More on that in another thread once I get it up and running).

To the problem. With almost everything I watch, to a some extent I notice visual distortion which is particularly prevalent around fine parallel lines, especially ones oriented horizontally, when either the object with the lines or the camera is in motion. I’m talking about things like stadium railings in background at sporting events, grill detail on automobiles, American flags, etc. I also get similar distortion around things like patterns in some patterned clothing. I see it in both SD and HD programming. I don’t know if we just call this digital noise, jutter, deinterlacing effect, or what, but it drives me a crazy. I’ll be interested to see if it is present in material from the 59avi.

I talked to a guy in the audio/video business a little about this, and he urged me to consider an outboard scaler. I’m a reluctant to make that move right now because I’ve pretty well nuked my a/v budget for a while, and a scaler would introduce the need to replace my receiver with one that could adjust the audio delay to address lip sync problems the scaler would probably cause.

The configuration of my Pro-910 is 1024x768, and I’m wondering if it would even accept 786p. from a scaler, or would it need to be sent in a “standard” rate? Also, no scaler I know of currently uses HDMI for either input or output. Therefore, data from the 59avi (and the soon to be acquired HDTV satellite box) need to be deinterlaced by those units before they are even sent to a DVI input on a scaler. Would this detract from the scaler’s effectiveness?

Thanks again.

Tom

tbuddha,
First I should point out that there's a whole forum here devoted to plasmas with many very knowledgeable Pioneer owners. There's also a forum specific to external video processors. Not to send you away, but just so you know the expert answers you are looking for may be waiting for you over in those forums.

As for scalers, you should take a look at the Iscan products from DVDO. Many folks connect to those via component cables, others have players modified to add a different type of digital output called SDI which is specific to 480i video. But the 59avi puts out 480i over it's HDMI output and DVDO has made public statements that they are about to release a firmware upgrade to one of their Iscans such that its DVI input will take 480i input from an HDMI device that will send 480i out. This is a neat hack if it works since DVI doesn't normally work with 480i.

Also, I believe the Iscan's have their own delay adjustment so that you can make sure your audio and video are in sync. They are really quite flexible, so I'm lead to believe -- I haven't actually used one myself. And they are HIGHLY regarded on this forum.

I don't know if your specific Pioneer will accept it's "native" 768 resolution as input, but undoubtedly the folks in the plasma forum would know.

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

The noise you are describing is a bit difficult to pin down at the level you've described it. The most likely culprits are poor de-interlacing and MPEG compression artifacts.

Since you are getting your SDTV from D*, you should be aware that MANY of their SDTV channels are WAY over-compressed as they attempt to cram more channels in before their new satellites are launched. Also you D* receiver may be doing a particularly grim job of de-interlacing. As an experiment you might want to try hooking the D* receiver to your plasma via S-video or Component cables at 480i, and let your Pioneer do the de-interlacing and scaling. That won't get rid of the MPEG compression noise, but at least you'll be able to see if the de-interlacing looks better. Also check to see if your Pioneer has a setting for doing film vs. video content processing. Film based content is brought up to video frame rates by the broadcasters by periodically replicating certain interlaced half-frames (fields). Whichever device is doing the de-interlacing of the video signal has to properly detect this or the de-interlacing of films will be screwed up. Most devices that do de-interlacing have an automatic detection for this. Some also have settings to FORCE film or video processing. If you've got it set to stick in film or video mode, it will screw up the de-interlacing of the other type of content. So, for example your sports TV might get screwed up if the device doing the interlacing was set to do film mode exclusively.

If the D* receiver is sending out a 480p signal then IT is doing the de-interlacing.

Now there's no real fix for MPEG compression noise, but your Pioneer may have some noise reduction settings that will reduce it. MPEG noise reduction goes under various confusing names like "mosquito noise reduction" or "digital noise reduction". Try some experiments to see if they help. These circuits will handle the modest/normal noise of MPEG processing, but will do nothing to remove the gross artifacts introduced by brutal amounts of over-compression.

As for off-air HDTV broadcasts, keep in mind that some of them are merely standard-def TV sent over the air as a digital signal. So when trying to focus in on problems here you'll have three different types of signal to consider: SDTV from D*, SDTV sent digitally over the air from an HDTV station that is "multi-casting", and HDTV over the air. When you get your satellite hookup for HDTV that will be a fourth signal type, since the satellite (and cable) HDTV services are all compressing their HDTV more or less as well these days.

Now the digital off the air signal, whatever the resolution, is also MPEG encoded. So the MPEG noise reduction features in your Pioneer may help here as well.

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Cabling is also an issue: I presume you are using AT LEAST S-video to hook things up. Component would be better, and digital connections better still. For heaven's sake don't use composite video or channel 3/4 style video connections with your good plasma.

For analog cables, you really can see the difference between cheap cables and average/good cables. You don't have to go to exotic cables, but do replace any real cheapies you have.

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In any event, before you spend a lot of money on fixes here, you really should pose your noise problem over on the plasma board and see if some of the Pioneer owners there have any settings to suggest.
--Bob

Thanks Bob,

I HAVE spent a fair amount of time on the Plasma board, and while I lurk more than I post I got very little response a while ago when I talked about this issue there. (I suspect all the Panny fans over there were just chalking it up to Pioneer.) There is a lot of good information there, particularly Rich Harkness' material. It has been very helpful, particularly with picture adjustments, but not with this problem.

I don't know how to better describe the noise problem bothering me. I'll give one more example. If I'm watching a football game shot from the sidelines, the lines on the field will look fine, but if the camera angle is from the end zone and fairly low so the yard markers appear horizontal and close together, then they come alive with noise. Again, this will happen with both SD and HD.

I'm aware that there is awful compression on some D*TV broadcasts, but the only impact it seems to have on this issue is that the better the PQ is, the more noticeable this problem is. You have to really look for it in a bad picture, but it jumps right out in a good one.

My SD source is a D*TV/TIVO box connected with superior quality s-video cables (high grade Audioquest). S-video is the highest output on that unit. There is no component output. As you noted, the PQ is all over the place depending on the particular broadcast.

My DVD is connected via component (Audioquest) cables, and I observe that my plasma seems to prefer getting an interlaced rather than a progressive signal from it. (Of course, my 59avi will be HDMI.)

The HD ota signal is from a built-in tuner in the Pioneer plasma itself. I know the difference between actual HD broadcasts and those that are only digital. I see this stuff with HD material, both the 720p from ABC and Fox (I guess) and the 1080i from the others.

My tv has "digital noise reduction" and also "MPEG noise reduction" settings, but they seem to have no effect on the phenomenon I'm talking about. I have experimented with them to no avail. I keep them set at “medium”. The “sharpness” is turned down, and the sharpness enhancement (CTI) is off. Also, while I sometimes get this kind of problem with film based sources if I don't have the "pull down" engaged, whether I use Pioneer’s exclusive 3:3 pull down, or the more usual 3:2 setting seems to make no difference with anything.

This is not a HUGE problem, just a nagging little thing, something akin to what I imagine the rainbow effect is with some DLP viewers. I’m hoping it is not something with the Pioneer itself that can’t be improved. I read a lot of stuff relating to home theater equipment here and elsewhere, and I’m surprised that I’ve never noticed anyone else complaining about this exact problem.

Excuse me for hijacking this thread. Your willingness to address people’s problems, plus your use of the word “scaler” in the title made it irresistible.

No problem.

Have you looked to see if this noise shows up in other Pioneer plasmas such as in store display models? I'd hesitate to suggest its a defect in your specific unit, but its probably wise to double check.

Sharpness processing would primarily show up on vertical edges (field of grass or such).

Mosquito noise can show up around any edge. It's also called dot crawl and that's a more descriptive name as far as I'm concerned.

There might be something mis-adjusted as far as vertical filtering goes. If so, fixing it would likely be a service menu adjustment.

However the problem sounds naggingly like a de-interlacing defect so that's where I'd concentrate first.

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

Probably the best thing to do would be to get a calibration DVD such as Avia, use it to double check the setting of your basic levels (whites/blacks/color/sharpness) and then go looking for test patterns that highlight the problem. Then at least you'll know you are dealing with a known source quantity and you can go back to the same images repeatedly as you try experiments to see what alters the noise. You can even compare the 59avi image to your older player.

While you are at it, you can use the test patterns to double check how much overscan you have and whether you are set to the proper stretch/zoom mode to avoid distortion. Image geometry issues can sometimes translate into artifacts like this as well as the scaler tries to do too much in the wrong place.

This is going to be tough to diagnose in words. You might have to get in a good ISF calibrator and turn him loose on the problem.

But when I was looking at Pioneer 50" plasmas last summer I spent a lot of time looking at various Avia test patterns and never noticed the sort of problem you are discussing, so hopefully there's something simple here we are overlooking.
--Bob

Bob,
Great thread. My question is this. What type of DVD player would be best for an 42" Panasonic ED plasma? It would seem that just a progressive DVD player would be best. Mine is currently connected via component but I have HDMI open for use.

RonMc,
The trick is you don't really know what your ED plasma does differently with a digital video signal (HDMI) until you try. If you have another HDMI source, such as an external HDTV receiver, then you can hook it up and separately calibrate Component vs HDMI cabling at the same resolution and see if there appears to be excessive filtering of your Component input signals.

You might get a different answer doing this experiment at 480p than at 720p or 1080i.

That is, even though your ED needs to DOWN-scale 720p or 1080i input, the final result might STILL be better depending on what it does differently compared to a 480p signal -- and the results might be different yet again with a digital video input.

It ought to be the case that a "mere" progressive player would be your best bet -- you've figured that out correctly. But even the ED designs sometimes have optimizations in them of various sorts to make them look their best when fed a 1080i signal since that's often the way they are evaluated in stores. And the progressive-only player designs usually don't offer either HDMI or DVI digital video output options.

And the use of the digital video connection may make enough of a difference (due to what your set does differently, internally, with that signal) that you might want to pay for an up-scaling player with it even if you end up only using that player at 480p.

I know this isn't much help, but the bottom line is that the only way to know for sure is to try it and see for yourself.
--Bob

Bob,

Not to copy anyone but your inside info has been a huge help. I have a question for you though i think the answer will be hard.

I have a new Hitachi 57s715 HDTV. the formats are 540 and 1080. I had a $75 JVC 410 progressive player hooked up and the picture was fine. (understand i am anal about the picture). I figured that i spent a lot on the set, why skimp on the dvd player.

I read lots of posts and went out and bought a Denon 2900 for around $550. I hooked it up via comp cables and then did both avia and dve adjustments. I can say it is a very nice player however there was no wow factor. I have played several movies and now i am considering that it might not be worth the $$.

My set does have an HDMI port and i am thinking of returning the 2900 and getting the denon 1910 which has dvi that i can convert. Maybe i am just chasing a picture that is not going to happen. I know everyone will say get the 1910 and take a look. It is just a lot of work if i am not going to see anything.

Any thoughts would help me alot!!

Thanks

Originally posted by Bob Pariseau
Probably the best thing to do would be to get a calibration DVD such as Avia, use it to double check the setting of your basic levels (whites/blacks/color/sharpness)
Hello Bob

I've just tried an upscaling player for the first time (using the 720p native resolution of my DLP TV) and I was very surprised to see edge enhancement all over the test patterns on the Avia calibration DVD. It made me nervous, because I wanted to check that the new player did not have a sharpness problem causing EE. I switched back to my component player and saw it there too. Is it really so? If it is, how else can I check for sharpness/EE problems?

Gary

Chris,
Actually if I recall correctly, the general consensus is that the Denon 1910 produces a WORSE picture than the Denon 2900 -- even using the 1910's digital video connection. If you can't afford to upgrade to the Denon 2910 you should probably stick with your 2900 or look to another brand. If I've mis-spoken here, hopefully some of the more knowledgeable Denon enthusiasts will chime in.

Even though your TV has both 540p and 1080i screen resolutions available, it is often the case that such TVs will only show 480i or 480p input signals at 540p no matter what settings you make. That is, the only way to activate the 1080i screen resolution on such sets is to feed the set a 720p or 1080i signal (and some such sets won't even accept 720p as a valid input format).

Meanwhile, the signal path that generates that 540p image may include excessive filtering and "enhancement features" which are really just going to get in your way when you feed the TV a high quality signal such as from your 2900. Those "features" are designed to try to make crappy input signals look more tolerable.

So if I make the assumption, perhaps incorrect, that despite what you are trying to do your TV is only displaying your 2900 at 540p, and the additional assumption that your TV has excessive filtering of 480i and 480p signals, then the lack of "wow" factor from your 2900 becomes more understandable.

The trick, then, is to find the right way to calibrate your TV to eliminate as much of that filtering as possible. Using a player with a digital video output might be the easiest way to bypass that stuff (a player that doesn't have the known imaging problems of the 1910). But you might be able to do it using the 2900 as well if you outsmart the TV's engineers.

You see, often such "features" are associated with particular "picture modes" on the set. Sometimes the only way to disable such stuff (short of getting into the service menu for the set) is to pick the "right" picture mode.

It is almost always the case that the picture mode that starts off producing the DARKEST and SOFTEST picture to begin with is your best bet. Set that mode and adjust from there just in case the mode setting is doing things in the background that you can't otherwise modify.

In addition, look at all the user settings available for "enhancing" picture quality AND TURN THEM ALL OFF! The usual culprits are "flesh tone correction", "ambient light sensing", "automatic gain control", "digital noise reduction", any other kind of noise reduction, and "velocity modulation". Turn all these nasty things off and then re-adjust the basic levels using your calibration DVD.

[Meanwhile, leave your 2900 in the factory default settings for progressive output.]

If that doesn't do the trick for you then you might even want to try a different input on your TV as the input you are currently using might have a problem.

Once you have set the levels the best you can, now go into the Avia test charts and start looking for problems. A good place to start is the resolution chart to double check you don't have sharpness turned up too high, and also the Y/C Delay chart to make sure color transitions will look clean.

If you see problems, your TV may need to be adjusted by a service tech for it's 540p display mode.

Also check that Blacker than Black data is getting through to your set properly. You can do that using the DVE calibration disc (but not with Avia) or by using the black level setting chart on the THX Optimizer found in the setup menus of some commercial DVDs such as "Finding Nemo".

To check for BTB data you have to *TEMPORARILY* turn up the Brightness on your display. If the data is NOT getting through, you may need to make a setting change on the 2900 for it's analog video output. What you want to look for is something labeled "Setup" or possibly "Black Levels" and change it from 0 IRE to 7.5 IRE or the other way around. THEN BE SURE TO RE-CALIBRATE! Otherwise your blacks/whites will be wrong.

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

Now the alternative is to go all the way to the other extreme and get your hands on a top end, upscaling player "for evaluation" from a place that has a no questions asked 30 day return policy such as Tweeter, Good Guys, or online from Crutchfield.

Hook up that player via a digital connection, set it to 1080i output, re-calibrate for that setup, and play some movies. That will give you a basis for comparison for just how good standard DVD playback can be. If it "wows" you then you can go on the hunt for a more affordable player that comes close. But if it doesn't "wow" you then you might need to set your expectations lower. The content coming off the DVDs is only 480i data after all.

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

It is also wise to double check that the basic setup for your player and TV really is what you think it is. For example, if you've mistakenly set your player to think it is talking to a conventional 4:3 TV rather than a widescreen 16:9 TV the image will be damaged even if you've found the compensating "stretch" mode on your TV to make the image fill the screen. Also, double check that you really are sending out a progressive 480p signal and that the automatic film vs video processing mode on the player for doing de-interlacing is in the factory default automatic mode -- and not turned off for example.
--Bob

GSB,
Have you tried turning off all "edge enhancement", "noise reduction", and "velocity modulation" features on your TV and picking a "picture mode" on your TV that starts off showing the DARKEST and SOFTEST image to begin with? And with those settings is it still the case that you can't eliminate this "ringing" by turning the Sharpness control on your TV all the way down?

Remember that the factory default settings on your TV are unlikely to be the ones you really want to use and that you need to adjust settings separately for each device you connect to your TV.

Since you are seeing the problem on two different players, the odds favor that your TV is causing this and simply needs to be set differently. Most manufacturers ship their TVs with brutal amounts of edge enhancement (sharpness processing) turned on as the "false sharpness" noise this produces helps to attract people to the sets in stores.
--Bob

Bob, yes, I did a full grayscale calibration of the TV, for both the DVI and component inputs, setting gamma to 0 (darkest), sharpness to 0, noise reduction OFF, DNIe OFF. I do not see the EE with some of my other DVD's. But the Avia DVD shows all sorts of pixelized compression artifacts, including EE, around the lines, letters and figures on many of the test patterns, especially the geometry/convergence patterns.

Gary

Bob,

Thanks for the reply. My set has a "virtual HD" setting. I can change this anytime to 540 or 1080 even with comp cables. Also does it matter if i run comp cables through the reciever verses going straight to the tv?

The tv produces a great picture. What i am not seeing is a wow difference between a $75 and a $500 plus player. I will have to look at the store for something other then the 1910 as i have credit for $200 there.

and the search continues....

Originally posted by Bob Pariseau
So here comes the 480i signal from your source -- complete with color data coming in at only half that resolution or less. Your DLP now wants to scale it up to 720 (really 768p).
Okay, time to beat a dead horse again! ;) According to this article (http://www.prillaman.net/ht_info_4-displays.html), here's an interesting quote:

For example, typical DLP RPTV's use a chip with 768 lines of resolution, allowing for a native 720p display resolution but requiring other hardware upstream of the DLP chip to scale 1080 images down to 720, whereas many direct-view HDTV's natively support 1080i resolution and scale up from 720p sources.
If I am reading that quote correctly, the DLP RPTVs do have an internal chip resolution of 768, but the 720p source is not getting scaled, unless the part "allowing for the native 720p display resolution" implies scaling.

Care to grab a stick and beat me about the head on this topic? ;) Seriously, I would appreciate any additional information you might have that would clarify his.

Michael

Michael,
A few displays with a "native" 768p resolution, display a 720p source without scaling -- simply leaving a smallish black border all around the image.

Most such displays, however, actually do scale the 720p source to 768p before displaying it. So, yes, the statement you quoted does, usually, imply scaling of the 720p source to 768p, much as the display would scale a 480i, or 480p source up to 768p or a 1080i source down to 768p.
--Bob

GSB,
Another thing you might want to check is to try forcing film or video mode processing while looking at those Avia charts and seeing if that changes the artifacts you are concerned with. You might be seeing de-interlacing issues instead of excess edge enhancement. Alternatively, send a 480i component signal from your player and let your TV do the de-interlacing as another way of checking if you are seeing de-interlacing artifacts from your players.

If your TV has internal "ringing" problems, the Avia or DVE test charts will tend to exhibit them rather strongly whereas typical movie DVDs will have the edges filtered softer to begin with.

On a properly operating player/display combo, those Avia charts should look quite clean up to the limits of the resolution available in your setup.

While you are at it, double check the Y/C Delay chart to make sure you don't have a signicant timing problem that needs correction.
--Bob

Chris,
Keep in mind that some of the things that make the more expensive player more expensive have nothing to do with image quality. For example audio quality and reliability.

Also some of the things a better player does "right" are tough to see if you don't know what to look for. It's the player properly handling "problem" DVDs that may only exhibit the problems at specific locations during the movie such as chapter changes.

In any event, if you are getting such a good image from your less expensive player you may have just lucked out. I think you need to try a few different players before coming to that conclusion however.

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

Most every receiver you can get today will switch standard definition (480i or 480p) component signals without problems, but it is easy enough for you to run a set of component cables direct to your TV and make this comparison yourself. Some receivers may not have enough bandwidth to switch high-def component signals as from an HDTV tuner without problems, but most new receivers will do that properly as well. In any event, since up-scaling DVD players send their high res signals out via digital video connections, and since your receiver can't act as a switch for digital video connections, this won't come up if you try an up-scaling player. Your HDMI or DVI connection will necessarily have to run directly to the TV.
--Bob

Originally posted by Bob Pariseau
On a properly operating player/display combo, those Avia charts should look quite clean up to the limits of the resolution available in your setup.
--Bob
Bob, I tried forcing film/video mode, and I tried sending 480i. Those didn't help, so I'm pretty sure it has nothing to do with deinterlacing. And the TV's resolution looks fine all the way through the upper-most frequencies.

Y/C delay is not perfect though, in 480i or 720p, so that could be a factor. Or perhaps you're right about internal ringing in the TV.

I'll try to find out more. Thanks.

Gary

Well Bob, I'm seeing the same Avia artifacts on my PC, using a DVI LCD monitor connected to an ATI RADEON 9500 card with the latest drivers and DVD decoder.

I have to look quite a bit harder, but there is a one-pixel highlight around any lines or letters that appear on a gray background. Some examples: Static Zone Plate, Overscan, Sharpness, Pixel Cropping, and Widescreen Enhanced Resolution patterns. The larger the screen or scaling, the more obvious it becomes. Also, any letters or numbers have blocky compression artifacts around them (CLEARLY seen on the Moving Zone Plates, because the artifacts wobble as the letters move).

I'm sure those artifacts ARE on the Avia DVD, and the DLP TV's very high contrast ratio (and inherent banding) is showing them off handsomely!

As for the Y/C delay, wouldn't that only become an issue in COLOR patterns? It shouldn't affect the black/white/gray patterns.

Gary

GSB,
I don't see what you are describing as "Edge Enhancement" artifacts using Avia with my 59avi connected HDMI to DVI into my Fujitsu P50/30 series plasma at 1080i using the factory default settings in the 59avi for "HDMI Direct" mode. With Sharpness adjusted properly, there is no ringing (haloing or highlighting) around black/gray/white lines against any of the backgrounds

I *DO* see "mosquito noise" or "dot crawl", particularly around the text. This is, indeed, an MPEG compression artifact, and is most noticeable with moving text as in the moving zone charts. Ovation wasn't sufficiently careful with their compression.

I also double-checked DVE. Again no signs of edge enhancement problems. Even DVE has a little bit of mosquito noise in certain portions of certain charts, but it is not as evident as around the Avia text.

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

The reason I pointed you at the Y/C Delay test chart was to see if there were any other indications of a signal path problems in your hookup. You are correct that Y/C Delay problems alone would not show up as artifacts in gray scale details.
--Bob

Thanks for checking Bob. I appreciate your input very much.

My setup is obviously making this problem unacceptable. The trouble is, I don't know whether the fault lies with the player or the TV. And both of them use the Faroudja deinterlacer/scaler. Maybe what I'll try next, is hooking the player to my DVI LCD monitor.

Gary

Oh well, the EE shows up on my DVI LCD monitor too. Definitely not as clear as it is on the DLP, but I'm sure that's because of the LCD's reduced contrast ratio. So the player is probably at fault. But I've seen it through composite, component, and DVI, with two different players and a PC. Maddening!

Gary

Thanks for all the good information. I have one question though.
I have a Denon 1910 connected to a Toshiba 51HX83. If connected with a DVI cable, what would be the best setting on the DVD player, Progressive ON or OFF? If it's set to on, would it be doing unnessesary work, since it's upscaling to 1080i (or whatever it's set to) anyway? Wouldn't the best setup to have Progessive OFF (480i) and have the DVI output set to 1080i?

Thanks,
Tyler

tjl,
I believe you are getting confused by a sloppy user interface (menu design) in your Denon. The "Progressive" menu item only alters the analog video outputs -- choosing between 480i or 480p output.

On the DVI output, what you get is entirely determined by the output resolution you select.

Internally, even if you select 1080i the de-interlace processing which produces the 480p "progressive" signal is still active. That's because the conversion chain goes as follows: 480i from the DVD is deinterlaced to 480p, then scaled to 1080p, then RE-interlaced to 1080i. It's done this way because it is almost impossible to do a good job of scaling an interlaced signal.

Note that the "progressive" indicator on the front panel may even turn off if you alter the "progressive" menu item, but that still won't change what's actually going on internally to produce that 1080i DVI signal. Think of it as just a reminder of how you've set your ANALOG video outputs in case you decide to turn off DVI and use, for example, Component cables that you have also hooked up.
--Bob

Thanks for the help! It all makes sense now. Too bad the manual doesn't mention it!

When I connect the 1910 with a DVI cable, the only way I could get blacker than black to pass was to turn on the Black Enhancement. With the DVE pluge pattern, the blacker than black bar would disappear as soon as the black enhancement was turned off. Anyone else experience this? It's unfortunate, because I don't like what the enhancement does to the picture.

Tyler

tjl,
Remember that you have to recalibrate, i.e., re-adjust the basic blacks/whites/colors/sharpness settings on your TV whenever you make a signal change like this from the player.

For Denon 1910 specific details, you should probably look for one of the threads in this forum for 1910 owners and ask the question there. Odds are this particular setup item has been discussed in stupifying detail in at least one such thread.

The Search function may be helpful here.
--Bob

GSB,
The following article has some good info on Edge Enhancement as a defect in DVD production including comparisons of different versions of the same movie. It also has examples that show the difference between high and low frequency Edge Enhancement with strong and weak variations of those, as well as differentiating between Edge Enhancement which is on the DVD itself as a production screwup (i.e., tends to halo all outlines equally) as opposed to that caused by vertical edge enhancement (Sharpness control) on players and displays (i.e., tends to halo vertical lines almost exclusively).

All that may be useful to you, but the most important thing I want you to check out is the screen shot of a portion of the Avia Sharpness test pattern that is towards the end of the article. That's what Avia is SUPPOSED to look like. As you can see, there are no Edge Enhancement artifacts on that Avia test screen.

Again, what you saw around the moving text -- mosquito noise -- is real and is really on the Avia DVD.

Anyway, here's the article. Hope it helps you isolate where your problem is coming from:

http://www.videophile.info/Guide_EE/Page_01.htm

--Bob

Thank you Bob,

I found that article very interesting and informative. I was amazed at how clean the Avia pattern looks there. So I can definitely eliminate the DVD as the source of the EE and put the blame squarely on my player. Unfortunately, the player does not have a working sharpness control.

Thanks again - I appreciate your efforts.

Gary

GSB,
Sometimes ringing in a player or TV (resulting in edge "haloing" or "ghosting") is due to an error in the signal path -- reflections of an analog format signal, improperly engineered filtering, etc. In such cases, the Sharpness control can ADD additional ringing in the form of "vertical edge enhancement" but can't eliminate what's already inherent in the signal path.

Sometimes (rarely) there IS an easy fix for this -- just use a different output/input pair. There are even cases where the same TYPE of output/input has different amounts of inherent ringing -- i.e., Component Out 1 is bad while Component Out 2 is good. If you are using analog video cabling, it is also wise to make sure you aren't getting signal reflections because you are using a bad cable or a cable with partially corroded contacts.

In addition, turning on or off some sorts of processing -- e.g., stretch/zoom -- may alter the signal path in such a way as to change the amount of inherent ringing -- all depending upon exactly where it is being introduced into the signal.

Unfortunately, there are quite a few players out there that have bad, inherent ringing -- shoddy engineering. So your best bet may be to simply switch to another player.
--Bob

Bob,
First let me be the 100th person to thank you for taking the time to help educate us on all of this. I started reading this thread under a cloud of confusion about what DVD player to get, and 7 pages later I am still confused but much more knowledgeable, :-)

If I may, I would like to summarize something I gleaned from your posts and have you tell me if I am correct in my assumption.

For a little background, I just got the Panny 50dl54 DLP and am looking at getting a new DVD player. Since the panny only has 1 HDMI input I was thinking of getting the Momitsu v880dx DVD player since it still does upconverting over component. My reasoning was that I would need/want to use my HDMI port for my HD Sat receiver when I get it so the DVD player would need to upconvert over component to justify the added cost vs a progressive only player (why buy an upconverting player then hook it up through component that does not upconvert). However, you mentioned in page 3 or 4 ish in this thread that a HD Sat receiver will most likely allow component connection.

My question is basically this: Would the PQ be much better when hooking up the HD Sat receiver through HDMI vs. component to justify bumping the DVD to component (and loosing the upconversion) or is the difference minor? I am still a bit unclear on how my TV will handle a native 720p signal from a HD Sat receiver, and what difference the analog component connection will have vs. keeping it all digital through the HDMI port.

Thanks in advance, hope you can shed some ligth and clear away the remaining fog!!

Originally posted by Bob Pariseau
Sometimes ringing in a player or TV... is due to an error in the signal path -- reflections of an analog format signal, improperly engineered filtering, etc. In such cases, the Sharpness control can ADD additional ringing in the form of "vertical edge enhancement" but can't eliminate what's already inherent in the signal path. That does make sense.

I'm using a purely digital player with a DVI connection, so that would eliminate the reflections possible with an analog connection.

However, I have a Faroudja processor, and I have heard that their "DCDi TrueLife Detail Enhancement" feature also introduces nasty edge enhancement. Is this true?

Gary

Buliwyff,
Personally I recommend hooking up your HDTV tuner via HDMI. There are folks out there who say they get as good -- some even say better -- images with their HDTV tuner hooked up via Component, but that's not been my experience with my HDDirecTivo combo box (HR10-250).

The difference is that ALL the HDTV tuner's will send 720p and 1080i via Component whereas only a scant handful of up-scaling DVD players will do so due to the push for copy protection in the DVD industry.

There's another solution however. There are HDMI switchers out there which will let you share your TV's one HDMI input with several source devices. Gefen and Dtronics are two brands that I know of and by now there's probably one or two others. They aren't cheap (think expensive cable costs), but that's how many people solve this problem. I'm using a Dtronics DVI switcher myself for just this reason (my Fujitsu plasma has a DVI input).

Now I don't know how much you are willing to spend on a DVD player, but none of the "best" players out there will up-scale over component cables. The Momitsu, Zenith and NeuNeo players (see the "options/impressions" thread at the top of this forum) all have their fans, but I don't think anyone really claims they are up at the level of the Denon 3910 or 5910, the Pioneer Elite DV-59avi, or the Onkyo SP-1000 -- all of which only up-scale via digital video connections.

So if you've got the bucks, a switcher is probably the way to go. But do some tests with YOUR HDTV tuner first and see if you happen to prefer what you get from it over Component.

Then finally there's the issue of whether an up-scaling player will actually be better for you than a good progressive player. As discussed in this thread, that's almost impossible to predict. If you take the time to do some experimentation with good progressive players (480p via component) then you'll know, but only as regards your TV.
--Bob

GSB,
I don't know the answer to that as regards the Faroudja feature. There are plenty of folks more familiar with Faroudja details than I am on this forum, but they may not be following this "newbies" thread, so if you are really interested in the details and tracking this down (rather than just switching players) you might want to ask this in a new thread with a Subject line identifying it as a Faroudja question. That might get some more of them reading it.

Keep in mind that even though you are running DVI to your displays, there are lots of displays out there which implement DVI on the cheap by simply converting it imediately to analog and then dumping that into the normal analog video input path. You might be unlucky enough to have different displays which each have their own internal ringing problems. If that's what's going on, then switching players won't fix the problem either.
--Bob

Thanks Bob, appreciate the response. Budget is not very large right now, trying to stick with the $200 - $300 range. A switcher might be the best bet, or going with a Momitsu and hooking the DVD up to component. In the short term it is a moot issue since I am waiting for the next generation DirectTV Tivo HD receiver to come out before I jump into HD Sat TV (and therefore can use the HDMI port all I want), but wanted to purchase something that will work in the future as well.

For the $$ the Momitsu is getting good press on this forum running at 720p through component, but it is a bit pricey compared to some other players like the Toshiba 5970 and can only be bought online. Currently reading all the posts about the different DVD players but no clear cut winner yet, lol.

Are switchers a pain to work with or is it pretty easy to toggle between HDMI inputs?


Thanks again for the response!

Bob, please disregard my last post as I found the Dtronics switcher online and it is pretty self explanatory. Seems like a switcher is not too expensive and I can always buy it down the road when I get the HD Sat Receiver.

I assume there is no loss of quality in the signals passing through the switcher, have you noticed any issues with yours or heard of any?

Originally posted by GSB
That does make sense.

I'm using a purely digital player with a DVI connection, so that would eliminate the reflections possible with an analog connection.

However, I have a Faroudja processor, and I have heard that their "DCDi TrueLife Detail Enhancement" feature also introduces nasty edge enhancement. Is this true?

Gary

From what I understand, this is adjustable in the Faroudja. Apparently on the Samsung HD931, the sharpness is turned up to 11 so it's oversharp, on others it's more natural. The majoe issue with Faroudja is the macroblocking.

Buliwyff,
There is no loss of image quality when working through a switcher. Digital connections either work or don't work. In fact the switcher also acts as a repeater so you can start over in measuring maximum cable length.

There have been reports from some people of compatibility problems with the DVI version of the Dtronics switcher -- apparently due to copy protection. I've not had any problems. The Gefen switcher also has a history of remote control conflicts. The Gefen remote triggers other devices and other device's remotes cause the Gefen to switch. I don't know if Gefen has fully resolved this yet. In any event, it would be good to make sure you understand the return policy of whoever you get these from so that you won't be surprised if you have a problem and have to return it.
--Bob

Originally posted by vksf01
From what I understand, this is adjustable in the Faroudja. Apparently on the Samsung HD931, the sharpness is turned up to 11 so it's oversharp, on others it's more natural. The majoe issue with Faroudja is the macroblocking. Thanks vksf01. So, with good firmware, sharpness could be user-adjustable in these Faroudja players.

Gary

Not sure how I ever missed this thread, it is now bookmarked.

Bob, thank you for all of your wonderful posts!

For all who've written thanks for this "newbies" thread, I really must say you are welcome. The most important payback has been in the reduction of the number of duplicate threads in this forum asking about this basic stuff over and over again.

I just hope to heck I haven't over-simplified/screwed-up the explanations too much. There are already enough sources of home theater "urban legend" out there.

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

If you'd like to provide payback in kind, I would recommend you double check the first post in another important "newbies" thread here -- the "Upconverting DVD Player Options/Impressions" thread. Mallu2u needs your help to make sure the summary information in that first post stays complete, correct, accurate, exact, precise, and, umm, up to date.

We could also use a good summary thread on the better "progressive" players actually still shipping (with perhaps loving reference to discontinued models that people might want to try to hunt down in the used equipment market). Too much info on progressive players refers to models that are not likely to be available in stores any longer.

We could also use a good newbies thread on the basics of calibration using Avia and/or DVE along with more advanced hints and tips to compliment the detailed info already found in the "Go to Guide for Source Options" thread. Ideally this would cover both video and audio setup hints. This would be for folks who still haven't figured out what those dang red, green and blue gelatin filters are for, or why you really should try to make most calibration adjustments on the Display itself rather than in the Player.
--Bob

Bob - One final question. How much data/frame is actually being displayed on a fixed pixel display from a dvd player in 480p mode? I know from digital photography that an uncompressed 1920X1080 24 bit color frame would be 6.22 megabytes. I'm trying to get an idea where dvd image quality sits relative to this standard.

chavel,
That's not easy to answer. It depends upon what the real resolvable resolution of the display is, which depends upon the display technology. As you probably know, for example, not all displays use the same horizontal resolution for the same number of vertical lines. It also depends upon how the data range gets compressed or expanded by things like gamma correction.

However one number is fairly representative. A 480p signal from the player is effectively made up of 30 frames per second of 720 x 480 x 8bits of luminance info and 2 channels of 360 x 480 x 8 bits of color info. Note that the frame rate is higher than the film frame rate for a movie on the DVD and also the color info has a higher vertical resolution than is actually on the DVD. The raising of the frame rate from 24 to 30fps and the raising of the vertical color resolution from 240 lines to 480 lines are both done by the player -- think of it as another type of "scaling" which is trying to fool the eye into thinking that invented data is real data. The horizontal color resolution is still limited however.

So what the player sends to the display for each frame is, effectively:

(720 x 480 x 8bits + 2 X (360 x 480 x 8bits) ) / 8 bits-per-byte = 691 Kbytes

The frame that comes off the DVD itself after removing MPEG compression is effectively:

(720 x 480 x 8bits + 2 X (360 x 240 x 8bits) ) / 8 bits-per-byte = 518 Kbytes

The difference being the reconstitution of the vertical color resolution. For movies the frames come off the DVD at 24 fps but are sent to the display at 30 fps by the trick of periodically duplicating certain interlaced half-frames or "fields".

But before you draw too many conclusions from these small numbers, keep in mind that the brain is also involved in processing these images. Film and TV frames have a high degree of coherence from frame to frame -- indeed this is why MPEG compression works. That means the brain can draw additional information from the frames on either side of any given frame to improve the perceived image. Of course the brain can't do that with a still image such as a digital photograph. That's why it's so easy to see the quality difference between TV playing normally and paused frames.
--Bob

I guess I'm having trouble visualizing three channels of data going to draw an image on a 1920X1080 or a 1280X720 fixed pixel display as you talked about in the beginning of this thread. It really sounds like current DVD technology is really mimicking an analog signal designed to be used with scanning crt displays. Will the new Blu-ray or HD-DVD technology still be using interlacing with different channels for luminance and chroma or will it be a single bit stream of data describing what color each pixel should be. I appreciate the answers for all the video 101 questions. Maybe you could recommend a video book for dummies.
-Chris

Books are passe. Use Google search and you'll find an amazing amount of stuff out there on technology questions like this -- most of it surprisingly accurate for free info.

DVD was designed as a transitional technology. It works remarkably well for all that but does suffer from some of the necessary design compromises.

Blue Ray and HD-DVD are still up in the air. Ask again later, the future is cloudy.
--bob

OK, I have read alot but not all of this thread. Have these questions been answered yet?

Why exactly are all DVD's 480i? I just don't understand why you can't take something that was digitally created like Toy Story and have it be 480p at the source. Has there even actually been something recorded and played back in true 480p, not just something that is 480i and then de-interlaced to 480p? Can someone prove to me that 480p really exists besides in theory?

How come I suddenly feel duped by the DVD industry after reading this thread? I always thought 480p meant 480p not some half-ass attempt to fool me and my brain damn it. Maybe my brain fills in some blanks but why the hell do they want to detroy the source only to struggle to recontruct it later? Please don't tell me it's all a capacity issue. If that's the case then maybe Blu-Ray is the right format to simply store true 480p movies with no compression. Imagine that. I bet a true 480p with little or no compression would almost look like a HD movie.

So all DVD is 480i and the progressive players are simply providing the same service as my tv: deinterlace the 480i signal. This would imply that if you have a good tv and a mediocre dvd player, then you can expect a better image if you turn off the progressive (deinterlace) in the dvd player and let the tv do it. Do I have it right?

The reason I ask is that I bought a new HDTV and my old DVD player (Toshiba SD-1500) only outputs 480i. I had borrowed a progressive dvd player but had noticed there was no obvious improvement in PQ. Which got me considering upscaling players, until I found this thread. Now I'm thinking that I should just keep my old dvd until the new HD players are widely available. Or at worst, get a cheap progressive player if ol' reliable craps out before then.

After reading this thread I just don't see anything that would lead me to believe that a progressive players has anything over a "non-progressive" player.

I doubt your TV would know to deinterlace the 480i signal coming from the DVD.

A new sony Rear projection LCD woudln't know how to deinterlace?

No, I'm not saying it wouldn't know how but rather it wouldn't try to deinterlace signals coming from the DVD player. At least I don't think it would de-interlaced it the same way a DVD player would to 480p. It would probably take the 480i signal and just upscale it to the LCD's native format.

Jamers,
Take another gander at the first post in this thread. Almost all TVs out there today *WILL* de-interlace a 480i signal coming in from a DVD player that has had its "progressive" output turned off.

This is done to improve the image quality for what is essentially the same signal as comes in when you watch standard broadcast TV (remember what I said about "line doubling" in that first post?) and also as a necessary prerequisite to any "scaling" of the image up to the TV's "native" resolution (since it is essentially impossible to scale an interlaced signal well).

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

As for 480i vs 480p on DVDs, I simplified my first post for clarity. DVD frames from sources like film or computer imagery are indeed recorded "progressively" and the DVD data includes flags which identify whether the fields making up each frame were recorded at the same time (film based) or slightly separated in time (video based) -- flags which the player has to interpret correctly or the resulting imagery will be screwed up, as with the infamous Color Upsampling Error (CUE). But it is still best to think of the DVD data as 480i since the player has to deconstruct the film based frames into their individual fields and put them back together again slightly differently as part of raising the film frame rate of 24 frames per second to the video frame rate of 30 frames per second. Then, if the player has been asked to put out a 480p signal, it has to de-interlace that NEW, constructed, stream of data.

Remember that the DVD standard was launched back when all consumer TVs accepted only 480i signals, and that all DVD discs and DVD players today still have to support TVs that don't have progressive inputs.

By the way, 480i and 480p are essentially the same as far as storage and data rates are concerned. A 480i signal consists of one interlaced half frame (field) every 60th of a second and a 480p signal consists of a full frame every 30th of a second.
--Bob

Bogen2 (and Teacherrob9),
Yes, your TV de-interlaces a 480i signal from the DVD player.

If you use a "progressive" player and send the TV a 480p signal instead, then it is the player that is doing the work of de-interlacing. It *SHOULD* be possible for the progressive DVD player to do a better job of de-interlacing, but as discussed in the first post in this thread that is not always the case. When progressive players first came out, it was rather common for people to discover that they preferred the image they got when they turned OFF the progressive option from the players and just used a 480i signal. Most such folks assumed it was just some peculiarity of their TVs when in fact they had just purchased a crappy progressive player.

Of course it is also possible that the de-interlacing in your TV is good enough that the "better" job a GOOD progressive player is actually doing might, nevertheless, be hard for you to see unless you really know what to look for. Often such ignorance is a good thing. Once you know what some of these de-interlacing defects look like, the more likely you are to find them.

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

Now de-interlacing, as important as it is, is not the only thing affecting image quality from a DVD player. For example, a new player might have a better (or worse) video output stage than your old player. If you use a calibration DVD such as Avia, you can check for indications of video signal quality by looking for ghosting of vertical lines in the Sharpness test pattern, color timing issues in the Y/C Delay test pattern, improper handling of the extreme black and white ends of the gray scale, and pixel cropping or other image distortion, etc. etc.

It is by no means guaranteed that a new "progressive" player must be better than a good quality, older, interlaced player. But generally the best players in each new generation of player designs have improvements to one degree or another across the entire design.

Audio quality is another factor that might push you towards upgrading.

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

If your TV has a digital video input (HDMI or DVI) then the current generation of "up-scaling" players adds that into the mix as well. As discussed in the first post, the digital connection alone may make a significant difference depending upon what your player AND TV do differently when using an analog vs digital video signal.

And of course the choice of scaling in the player vs. scaling in the TV also might affect what you see.

There's no easy answer to whether upgrading today is worth it -- particularly if you think you might be an early adopter of the future high-def DVD technologies. You just have to try it and see.

If you don't mind buying and returning an expensive player, you could pretty much settle this for yourself by getting a top end up-scaling player such as a Denon 5910 or 3910, a Pioneer Elite 59avi, or an Onkyo SP-1000, and trying it on your TV at home. That would show you right away just how good current designs are. If you still can't see a significant difference compared to your old player, you can save yourself the money even if you were actually thinking of only buying a cheaper new player, since you can feel confident that any of the cheaper players will not improve on the image quality you can get from these top end players.
--Bob

Good original post for the most part on Bob P's Behalf.

Only one thing I have a major issue with the post and it's restated several times that DLPs have 768p resolution.

All DLP RPTV sets that have been released to date are true 720p - NOT one DMD Chip (Digital Micromirror Device - That's what the DLP is based on) has a 1280x768 mirror pattern (they have 1280x720.) Most LCD and LCoS RPTVs on the other have either a 1280x768 or 1366x768 pixel pattern (none have a 1280x720 pixel pattern.)

CCourtney

that confused me as well since i looked at this thread after going to the samsung website in their faq's where it indicates all dlp's are 720...lcd's are 768 and plasma are 768

c1courtney,
Thanks for the catch! (And mhock5, I'm sorry my error confused you.)

I don't use a DLP myself and assumed (without checking) that DLP manufacturers had set them up with the higher line count for the same reasons most of the other fixed pixel technologies do -- sources of supply are dominated by PC needs and even consumer TVs want to enable use as PC monitors at "standard" PC resolutions.

I gather the current crop of DLPs are really targeted exclusively at the home theater market and thus don't make any "native" pixel count allowance for the common 768 PC resolution.

I'll put a correction in the first post in this thread.
--Bob

Bob,

That's a good summation of it. You'll find many DMDs w/ common PC resolutions in DLP FPs (which you'll find in many more conference rooms than HTs - 12 different resolutions are listed on the dlp.com for FPs) but you'll not find them in the RPTVs due to the demand to have true 720p display.


My guess as to the reason behind this is that most LCD manufactures re-use the LCD panels that are in their FPs in their RPTVs. This being do to multiple manufactures and fewer LCD FP and RPTVs than DLP FP and RPTVs made today. This would mean the cost of multiple designs for the industry is higher than DLP with a single Manufacture which is now producing at a rate of over 2 million DMDs a year.

CCourtney

Interesting scaling information:

http://archive.avsforum.com/avs-vb/showthread.php?postid=708386#post708386

http://archive.avsforum.com/avs-vb/showthread.php?s=&threadid=198850

Add me to the chorus of thanks. I imagine this is the incorrect place to post this, but I've been unable to find a better location.

An current limitation in PQ for DVD is the fact that all DVD is 480i. While this is certainly not as good as HD, it can still be pretty good with decent equipment. Why then is all other 480i content (OTA, Cable, Digital Cable) absolutely terrible? Do all of these seperate distribution chains damage/compress/mangle the signal that much? Is satellite better?

I'm loving my HDTV, and the HD material I can get. I'm also very happy with the PQ I'm getting from DVD, even though it's not HD. If all 480i content was remotely close to dvd I would be thrilled. I wouldn't complaining nearly as much about the lack of HD available to me.

Trying to get a handle on all of this!

On the first link above, I took an informal survey with others in my office. Standing at about 15' from my 17" LCD display looking at the two images, there is no meaningful difference. If you get closer to the point where your eyes CAN see the pixilation of the lower image, of course you see a difference. But further away, the images look very much the same.

It appears to me that all the scaling and other processing that goes on cannot really improve the image above how it is natively stored or transmitted. Its how your eyes see the display device and its artifacts (pixels or scan lines) that makes the big difference.

So I don't agree that upscaling a 480i image to 1080i and then descaling it to 768 or whatever really "improves" the image. It’s just that the kinds and nature of the distortions or non-lineararities introduced by the signal processing are not annoying enough to be noticed. By definition, scaling is adding best-guess data to the material or subtracting data - it is never a true 100% transfer function and thus distortions are always introduced. Massive up and down scaling can only introduce unwanted visual artifacts.

Deinterlacing is also a best-guess process since most material is not 100% properly coded as to how to deinterlace it(3:2 pulldown, 2:2 pulldown, interlaced, non-interlaced and so on). So the deinterlacers make "best guesses" about how to process the signal, and even the best devices make mistakes from time to time as the source flags are either ambiguous, misleading or downright wrong. It would appear that good deinterlacing produces the best perceived PQ improvement with the least amount of damage done to the image as the data of the image is not changed, only its presentation timing.

So it would seem to me that the least amount of signal processing done to a signal results in the better image. Since there is little to NO source material that matches the native res of the digital displays on the market, then the shortest path from source format to display format with the fewest A/D or D/A conversions and the fewest scaling steps is the best.

(I’m floating around on the surface of a large body of technical considerations and trying to sort this stuff out. So I’m not preaching, I’m posing a point of view for discussion and analysis.)

Count

>>>"So I don't agree that upscaling a 480i image to 1080i and then descaling it to 768 or whatever really "improves" the image."<<<

I don't think anyone was talking about upscaling, then downscaling an image so it looks better. The point was that watching a 480 line source on a 480 line display was not the ideal situation. As was adequately demonstrated, you want the display to be of higher resolution than the source material.

"Best guess data", as you call it, can reveal information that a lesser line display cannot resolve. There is also some excellent information on scaling techniques and what they can reveal from a lesser quality source in the Video Processor forum. The pertinent thread is the DVDO iScan HD thread. I believe the relevant comments can be found somewhere in the first third of that thread (Caution: it's one looong-ass thread).


>>>"But further away, the images look very much the same."<<<

The further you are from a display, the less resolution you need. That, of course, is because an eye's resolving capability decreases with distance.

There is a mathematical formula that takes into account the resolving capability of the human eye (based on 20/20 vision) to determine how far away you can sit from a display -- taking into account the size of the pixels used in the display -- to not be able to resolve a pixel.

If you'd like, I'll look for it and add it to this thread. Unfortunately, it will probably just be another topic to argue over...

Joe,

Thanks for the post - I'll read the iScan thread as I am interested in learning as much as I can on the breadth and depth of HDTV and av systems.

My search here (like many others) is to find a moderately priced DVD player that does not contribute to unwanted image artifacts and to learn more about what to look for and what to look out for as I assemble my av system. It appears that really objective reviews of a/v gear is scarce (there is some, but not much), and so you end up relying on opinions expressed in forums such as these. So I'm trying to balance the complex and not well understood (by me at least) technical side of HDTV and the equally valid but harder to qualify subjective evaluations I read.

The good and bad news is I have a couple of months before I have to make a decision. Good as I have more time to learn - bad, because I have more time to become overwhelmed by what I learn!!

Count

I'm just jumping into HD after many happy years in projected SD( Sony D50 w/line doubler ) giving me a nice image with deinterlaced broadcast TV as well as a silky smooth 480p DVD( original Sony 7000, glitch free to this day).
And then I made the decision to upgrade my satellite receiver to HD with big hard drive( Dish 921)...and whoa! the old and wonderful 480p doesn't look quite as terrific any more. The HD image grabbed me real hard. And this was only 720p(mostly). With 1920x1080p coming down the road, I began to drool. My old box offered only 1280x1024i max. and it was time to retube or sell. I sold, and I have the new Sony HS51 on order. I know it should last me about two years before panel costs come down enough to where enable affordable real 1920x1080p boxes. I was really turned off by some present illumination costs running ~ 1$/hr.
I had been fairly comfortable with the operating parameters of the analog world, sockets, cabling et al.
I'm reading as fast as I can, literally hundreds of AVS pages. I'm moderately computer literate but have no desire at all to bring HTPC into my living room. I'm a last row of the movie theater person, ans also watch at home at three screen widths. It is likely that most of the artifacts alluded to are invisible to me most if not all of the time.
This thread has been great at fleshing out my growing understanding of what's happening. My thanks to Bob and the other contributors.
I surely will watch HDTV in 720p/1080. My thought is to initially use the HDMI connection on the PJ with the HDTV receiver this terminates in a DVI. As DVI for Home Theater disappears ( this is my current assumption) and as we move to HDMI fully, my thought is to put an DVI/HDMI socket converter right at the receiver and use a good quality HDMI/HDMI for the whole path to the PJ. This approach will provide a useful cable for any future use. This is not what the cable companies recommend in print. If my assumptions are wrong I would appreciate being corrected.
The DVD player area gets muddier. I have several 480i/480p players.the were only used in 480i mode.( I used the superior deinterlacer of the Sony CRT PJ ). As a first thought, I might be satisfied with the old 480p ( never seen before?) brought to the new PJ.
The thought of upscaled DVD, 720p( with the silky images I saw at a local Fry's) does appeal. I'm not prepared to spend big bucks on a box that will be obolete in less than two years by the combo players coming down the road. Everything I read, says the HD/DVD players will also play the current SD; whether upscaled or not I don't know. I'm also not prepared to invest in an outboard scaler at this time. The ones I would afford do not deinterlace 1080i to a real 1080p. They use the "bobbing" method which delivers only half the vertical resolution or 540p...this wont cut it...I'll wait.
I've sort of decided ( if I decide my 480p is not enough) on the Momitsu 880DX. This upscales the component-out as well as the DVI out. This will appear to give most flexibility so I can keep my 720p everywhere but the old legacy devices, and try the HDTV with DVI OR Component.
I know it is a Q.C. dog but I may be willing to take the chance for the potential it affords at quite low cost.
Is my approach reasonable or have I overlooked some major factors.
( I've been devouring the cable company tutorials...tough reading..the proverbial Heinz 57 Varieties).
Thanks for reading this long post!
Brian

www.hometheaterhifi.com

Check out the Benchmark section. Plenty of reading available written by some very highly regarded people in the video world. While some of the player evaluations are subjective, the majority are objective. Many of the tests are pass/fail and are not subject to interpretation.

I just got the new issue of Perfect Vision and Shane Buettner's annual DVD player review. He had said that the "upconverting" thing has been "hyped" and the "cleanest" resolution is always at 480P. I have been reading many posts about DVD players and seeing the word "upscaling" with almost every thread. Bob's great synopsis points out that the digital connection thing serves the manufacturer's interests in order to sell another round of DVD players, helps protect DVD producers from copyright infringements and at best, any appreciable improvement using a digital connection is far from a slam dunk (as it is mostly display dependent). I am trying to get a handle on this thing and don't follow all the conversion lingo associated with the various native resolutions. I also have a hard time understanding in light of all that information why people are getting so excited about budget brands like Zenith and Samsung DVD players. I asked a sales guy at Tweeter whether an "upscaling" DVD player like the Panasonic S97 is worthwhile and his answer was that "if the scaler in the Panasonic is better than the one in your TV, you have problems". I am sure his advice is flawed and there are many counter- arguments but it has me thinking. It seems reasonable that an expensive "upscaling" DVD player like the Onkyo, Denon and Pioneer could have benefits in the right application but nevertheless still confusing. I don't know whether this is appropriate or correct to post this here but I came across some good information on digital connections from a "Jamie Wilkens" website on ecoustics:

"Both signal types, then, are fundamentally quite similar; they break up the image in similar ways, and deliver the same type of information to the display, albeit in different forms. How they differ, as we'll see, will depend to a great extent upon the particular characteristics of the source and display devices, and can depend upon cabling as well.

Isn't Digital Just Better?

It is often supposed by writers on this subject that "digital is better." Digital signal transfer, it is assumed, is error-free, while analog signals are always subject to some amount of degradation and information loss. There is an element of truth to this argument, but it tends to fly in the face of real-world considerations. First, there is no reason why any perceptible degradation of an analog component video signal should occur even over rather substantial distances; the maximum runs in home theater installations do not present a challenge for analog cabling built to professional standards. Second, it is a flawed assumption to suppose that digital signal handling is always error-free. DVI and HDMI signals aren't subject to error correction; once information is lost, it's lost for good. That is not a consideration with well-made cable over short distances, but can easily become a factor at distance."

The argument often made for the DVI or HDMI signal formats is the "pure digital" argument--that by taking a digital recording, such as a DVD or a digital satellite signal, and rendering it straight into digital form as a DVI or HDMI signal, and then delivering that digital signal straight to the display, there is a sort of a perfect no-loss-and-no-alteration-of-information signal chain. If the display itself is a native digital display (e.g. an LCD or Plasma display), the argument goes, the signal never has to undergo digital-to-analog conversion and therefore is less altered along the way.

That might be true, were it not for the fact that digital signals are encoded in different ways and have to be converted, and that these signals have to be scaled and processed to be displayed. Consequently, there are always conversions going on, and these conversions aren't always easy going. "Digital to digital" conversion is no more a guarantee of signal quality than "digital to analog," and in practice may be substantially worse.

Forgive my ignorance, this logic seems more reasonable then believing that a $200 "upscaling" DVD player can significantly enhance a DVD image vs. progressive via component. I tend to agree with Shane Beuttner about this digital connection thing being mostly hype, I don't doubt that people believe that there is a dramatic improvement with a digital connection but it just seems to be along the same lines as that some of us hear big differences in speaker wire and audio cables and some of us don't. My component cable going from my Onkyo SP1000 to be RPTV 57" Hitachi Director's Series TV has a wonderfully detailed and sharp image, its more like watching hi-def than a film. If a digital connection could improve it further, it would be amazing.

While I do respect Shane Buettner's opinions, I have to disagree with those comments and the others that you posted. I would suggest reading Greg Rogers' reviews in WidescreenReview for some better information. If you think that any more than a very very small percentage of today's displays use state-of-the-art chips (A/D converters for one), you are mistaken.


Please explain what you mean by this:
>>>"T...the fact that digital signals are encoded in different ways..."<<<


And as to:
>>>"That might be true, were it not for the fact that digital signals are encoded in different ways and have to be converted, and that these signals have to be scaled and processed to be displayed. Consequently, there are always conversions going on, and these conversions aren't always easy going. "Digital to digital" conversion is no more a guarantee of signal quality than "digital to analog," and in practice may be substantially worse."<<<

did it ever occur to you that the majority of digital and/or analog processing that goes on inside of a display takes place regardless of whether the signal was entered via a digital input or an analog input? Or do you really believe that the internal analog and digital paths are truly 100% independent?

Joe,

You are probably right, I really don't understand the science of it and certainly couldn't go toe to toe on any sort of a debate. Like I said, I am just trying get a handle on it because my new equipment has the availability of going to a digital connection but its a big undertaking to get behind my TV and I wanted to make sure that it was worthwhile before I took apart my wall unit. My intention is not to take somebody's opinion and make it something its not, for the record, Shane's article is by no means anti-digital connection, you have to read the Perfect Vision article and decide for yourself. As far as Jamie Wilkens' theory, you have to read his entire article to understand the full point he his trying to make as well. Your logic seems reasonable but so does some of the others, who knows.......like I said, Bob P. probably nailed this thing way back.

Personally, I don't see any difference in picture quality between HDMI and component on my set. But having 1 RG59-sized wire is way more convenient than the bundle of coax video plus audio cable.

One (of several things) I'm sitll confused about is how the dvd player's DAC fits into this if the HDMI connection is used.
If the signal over the HDMI is digital then if any dgital to analog conversion is done it would be done by the tv, correct? Or does the dvd player's DAC still somehow play a role in this?
Also, want to add that this has been a great thread to read (and re-read).

Originally posted by Ahab
One (of several things) I'm sitll confused about is how the dvd player's DAC fits into this if the HDMI connection is used.
If the signal over the HDMI is digital then if any dgital to analog conversion is done it would be done by the tv, correct? Or does the dvd player's DAC still somehow play a role in this? If you're referring to the video DAC's then I wouldn't think they would be used with HDMI. But not everyone that buys an HDMI player will use that output. As long as they provide other outputs like component on the player they have to have the DAC's.

You're correct. When using the HDMI connection, the DVD player's video DACs are not in that signal path.

It's rather sad that we don't have DVD players that are all digital. There's no reason that DACless players can't be produced -- even for the general public. If you need an analog output, all you'd have to do is buy a player with analog outputs. An all digital player from a manufacturer wouldn't kill anybody.

Hopefully the developers of the next generation formats can see further than their longest nose hairs.

Originally posted by kdog044
If you're referring to the video DAC's then I wouldn't think they would be used with HDMI. But not everyone that buys an HDMI player will use that output. As long as they provide other outputs like component on the player they have to have the DAC's.

Thanks for the info. I'm wondering if the video DAC in most hdtv's is better than what one would find in a good upconverting dvd player. If not, then I guess that might be a situation where it would be better to stay on component cable rather than switch to hdmi.

Originally posted by Ahab
Thanks for the info. I'm wondering if the video DAC in most hdtv's is better than what one would find in a good upconverting dvd player. I don't understand the question. If you use HDMI and send to a digital display it shouldn't need the video DAC's. I know Samsung and Toshiba keep the signal intact. Sony is the only one that I know of that converts the signal to analog. I've heard that Mitsubishi might also but haven't seen any signal paths on their displays.

kdog044, I have a Sony KDF-50WE655. I was under the impression when I got the tv that it kept everything all digital through the hdmi, but, as you say, it apparently converts it to analog almost immediately. I have a pioneer 59avi on the way and had planned to get an hdmi cable and hook it up that way, but now am wondering if I wouldn't be better off just leaving it on component.

Originally posted by Ahab
I have a pioneer 59avi on the way and had planned to get an hdmi cable and hook it up that way, but now am wondering if I wouldn't be better off just leaving it on component. I've heard that the scalers in the Sony are pretty good so you might have better results using component since the Sony will have to convert it to analog anyway. The only sure way to know is to try both and compare. Just make sure you can return the HDMI cable if needed.

soldonandy,
I have been talking to manufacturers engineers,techs, and reps for some time about this and the core of your last longish post is what we in the industry have been discovering for some time now.
An "upcnoverting" source can do that conversion well or poorly and given that many fixed pixel devices may still "treat" or scale that incoming signal, the arguement becomes which is likely (or demonstrably) doing a better job....we live in A-MORE-ICA where the consume believes in the almighty magic # , if the dvd player is magically making 1080 out of 480 then it's going to be better right? Of course when you try to tell them that the display device then is making it 768 , you get a confused look....
In practice with cable boxes we found component to look better than dvi , and on most of the dlps, plasmas, front prodectors(mostly dlp as well) and lcds , the displays did a better job (subjectively) with incoming component at 480 than any "upconverted" dvi/hdmi resolution we've tried.....indeed if the scaler/ video processor in your $250 dvd is better than the one in your display, you DO have a problem.....
All these are generalizations, and anecdotal (even if many anecdoal examples) , and I hope these issues may change in the future...

Hey thanks for the explanation, I just was browsing by and actually even forgotten that I posted on the subject a while back. Nevertheless, I appreciate your explanation.

Hi! I'm the customer who bought the Toshiba 5970 that works. I gather from reading these threads that I am the only one in the world with a working one. Bidding starts at 10k. Seriously though I have my Tosh 5970 hooked up via HDMI to a Tosh 34HF84 direct view analog TV. I understand the debate about whether or not an upconverting player can benefit a non fixed pixel display. I can't add fuel to the fire. My former DVD player was old and hooked up to old analog SD cheap set. Bought TV and deck at same time. Naturally current PQ is far superior. I do have an issue. On DVD's like Lord of Rings or Troy PQ is great! On some other DVD's looks slightly washed out. Has been calibrated by Greg Loewen so that is not issue. Anyone comment? Am I just looking for things not there?

What's the diff between a Sammy 850 and 950? Its not so obvious looking as samsung.com.

Bob,

Thanks for the post. I am a newbie here and am learning alot from all the information posted. I do have one question, concerning the purchase of a DVD player for my newly acquired LCD. I am considering the purchase of the Denon 5910, but am also concerned that it may soon be obsolete. Do you think I should settle on this player or wait for HD-DVD.

Thanks for your help.

Great info Bob...what an education!

If I understand you, that all DVD's are recording in 480i (or 480p if you count what comes before the DCA or whatever chip or use HDMI) then I believe this answers all the many posts on the forum about widescreen recording - it makes no difference at all! Is that correct? I might as well just record in 480i and stretch or zoom since there is really only 480 anyway? Then why so much bother that this and that dvd recorder doesn't record in widescreen, like the Panny ES10 I just got out of box for a song :-) It shouldn't matter?

And that also deals effectively with all those posts about recording DVD's to a PC so you can change that header bit with some editor so it will play back in widescreen mode. That never made sense to me since changing that bit couldn't really add more data to the file, so isn't it just changing the default playback upconversion when the player reads the disk, something we can do manually with stretch and zoom or something anyway?

I am really trying to understand all this...so bottom line, should I invest in DVD-Video disks for my ES10 so I can record in widescreen, or get the cheapest disks on sale I can find and not worry about it???

Again, we all really appreciate the time and effort you obviously put into making something very technical understandable to us grunts :-)

Regards,
RawFoodGuy

Some may benefit from a DVI connection, but as stated before, you'll have to do the homework for yourself and examine the differences between component and DVI. If you have a Hitachi set similar to mine which is a 51S500, you'll likely see less ringing using the DVI connection. You have to be watching a DVD without edge enhancement to get the proof, otherwise EE and scaler ringing look almost the same. This is not a huge deal, but if you're a bit obsessive like me, then you want to squeeze out that last ounce of PQ.

Ok I have been asking questions like this all over the place, but maybe the thread starter (or anyone) will know the answer to this.

Ok I have a Toshiba HM5284 DLP. I have a Rotel 1056 receiver. My tosh has 1 HDMI input, and I have no idea if it Y/Pbr/Pbc (or whatever) or the other one he was talking about. I didnt know there was any different type of HDMI cable, or maybe it ws just the source...I dont know.

Well anyway my question has to do with the Panasonic S97/77 DVD player. Would it just be better to hook it up with component inputs than HDMI, since my TV is already going to do the upscaling? And if so, are there better plain old "progressive DVD players" in the same price range as the S97/77 that will give better PQ and SQ? If Im not going to be using the upscaling ability of the DVD player, then why would I even worry about buying an upscaling one? You know what I mean?

My understanding is that upscaling (I think you mean upconverting) is mostly marketing hype. From what I read on this forum, some upconverting schemes actually make the picture worse. I can set my SA8300HD to use 2 different types of upconverting and when I try them, neither looks that good anyway, so I leave it set at fixed so I can zoom in or whatever as I need to manually.

I hooked up my SA8300HD DVR both on the HDMI of my Panny 53" and through the component cables, and frankly I can't see a difference. But I use the HDMI anyway because I have the cable so might as well, and even if there is no discernible difference to my eyes, in theory at least (so I hope) the digital should be better.

Perhaps we can get a better explanation from one of the more technical types on the forum...but that is at least my own experience so far. And as someone that intrinsically distrusts marketing, I assume that upconverting is how companies sell more units to people with a passion for the best technology has to offer, especially like us. They even have a word for us - "early adopters." We'll buy these upconverting DVD players even if they make the picture worse because we believe the hype. Thanks to this forum, we can do a bIt of research and get an education from the kind folks that actually know what's up and are willing to take the time to share their knowledge - so a big THANK YOU to them - you know who you are!

Regards,
RFG

If you read the root post on this thread, you'll find the answers to what scaling aka up-converting is all about. The net-net is: who does it better? Your display or the dvd player?

The best answer to try it out with your gear to see which one gives you the best image. New dvd players may have better scalers than older displays - and maybe not...

thnx for this very educational info can i print this and show it to my colleagues??

Ok, here is my question:

Will an upscaling DVD player, such as the Sammi, Tosh or Oppo provide a signal at 720p to a Samsung HL-P5674 in such a manner that the TV will not be required to re-scale the image. Thus allowing the use of the "expand" picture setting and acheiving a 1:1 mirror to pixel image on the screen?

Will the upscaled image from the player be a better quality image than one scaled by the TV's up-converter?

In this mode of operation, as I understand the mechnaics, the HD2+ chip with 1280X720 mirrors would be able to process a 720p image at a 1:1 ratio, allowing it to fill the viewing area when the image is expanded. I intend to use either the HDMI or DVI inputs for this application.

I'm still fairly new to the forum and HDTV but find the information very valuable and informative...all advice would be greatly appreciated, as I am currently going insane. :confused:

Squashie

I'm in the same boat as Squishie. Is there/should there be a substantial improvement in PQ by sending a 720p signal to a Sammie 5674 to take advantage of the "expand" setting?

Tanks, Arch

all this is making my head hurt.... would i be crazy to stick with my 4 year old Toshiba SD-2109 non proggressive player with my new sammy R4667?

all this is making my head hurt.... would i be crazy to stick with my 4 year old Toshiba SD-2109 non proggressive player with my new sammy R4667?
Recommend a DVD that'll output at least 480p.

I read this and wondered if you had looked at the DVDO HD+?

"k, here is my question:

Will an upscaling DVD player, such as the Sammi, Tosh or Oppo provide a signal at 720p to a Samsung HL-P5674 in such a manner that the TV will not be required to re-scale the image. Thus allowing the use of the "expand" picture setting and acheiving a 1:1 mirror to pixel image on the screen?

Will the upscaled image from the player be a better quality image than one scaled by the TV's up-converter?

In this mode of operation, as I understand the mechnaics, the HD2+ chip with 1280X720 mirrors would be able to process a 720p image at a 1:1 ratio, allowing it to fill the viewing area when the image is expanded. I intend to use either the HDMI or DVI inputs for this application.

I'm still fairly new to the forum and HDTV but find the information very valuable and informative...all advice would be greatly appreciated, as I am currently going insane."

What is currently the greatest scaler in the history of the universe? If you hooked it up to a TV that was showing live pictures from a landfill would it be indescribeable or just a bunch of garbage?

Soooooo confused. My TV (Panny 42px50u) has 2 component inputs and 1 HDMI input. It sounds like if I am going to use the component input for my DVD player (and HDMI for my cable box/DVR), then I might as well just get the $30 DVD kit for my XBox since 480i is the best I'm going to get from the DVD and Xbox and anything "better" than that going into component inputs is probably wasted.

If however, I use component inputs for my cable box and leave the HDMI open, then it makes sense to get an upscaling DVD player that has a HDMI out since that information will not be lost as it would through an analog connection.

Is that correct?

Note: I'm getting a cable card in addition to the cable box/HD-DVR so PQ through component for the box isn't really an issue. If I want ultimate PQ for TV I'll go through the cable card.

Thanks!

-p-

Bob Pariseau..... Who is this guy??

I would call him the "deep throat" of the dvd and digital transmission industry.

Nothing rude meant by the term deep throat. Maybe I just watch too much X files. :D

Ben

Does anyone know how good the de-interlacer/scaler in the Samsung LN-R408D (40" LCD, 1366x768) is? Is it worthwhile to buy an upscaling DVD player or not? Or is it worthwhile only if the DVD player has a Faroudja chip?

Thank you Bob for a very entertaining and informative writeup. I have read a number of times and still learn something new.

:D

So if I understand this right ........... I'm better off just sticking with a good prog' scan dvd player and calibrating my DLP tv right since there are little to no gains in using an upconverting dvd player(using the HDMI input on my tv (which b.t.w is a sammy 5067))?? Is this assessment correct ????

So if I understand this right ........... I'm better off just sticking with a good prog' scan dvd player and calibrating my DLP tv right since there are little to no gains in using an upconverting dvd player(using the HDMI input on my tv (which b.t.w is a sammy 5067))?? Is this assessment correct ????

Disclaimer: I am as new to this as you are (note # of posts), so any answer I provide may be ignorant, uninformed, or potentially just plain wrong! However, I have read much, and will give it a shot based on the way I read the info provided on this (most excellent) forum. :)

1) In general, it is better to have a DVD player that will output a digital signal (HDMI or DVI) so that you avoid the D/A and A/D conversion steps.
2) Depending on how well your DLP does the processing (de-interlacing and scaling), a good DVD player might do this better than the TV. My basic understanding is that the processing chips/algorithms by Faroudji (or others) are supposed to be good (best?), and those are typically found in mid-high end DVD players, not TV's. However...
3) I have seen a lot of posts about problems with visible Macroblocking with players using the Faroudhi DCDi chipset. MB is some watermarking technique used for DCP, :mad: and I think is only a problem over digital connections. I'm not at all familiar with this problem, and can't comment any more than this.

So in the end, does this answer your question? Not really. :confused: If you don't want to risk spending $$ and ending up with a system that is only marginally better (or maybe no better at all) than your current setup, then I wouldn't spend any $$. As for me, I will likely buy a new up-converting DVD player to go with my new Sharp LCD panel, and hook it up using HDMI, and hope for the best.

-Jay

Disclaimer: I am as new to this as you are (note # of posts), so any answer I provide may be ignorant, uninformed, or potentially just plain wrong! However, I have read much, and will give it a shot based on the way I read the info provided on this (most excellent) forum. :)

1) In general, it is better to have a DVD player that will output a digital signal (HDMI or DVI) so that you avoid the D/A and A/D conversion steps.
2) Depending on how well your DLP does the processing (de-interlacing and scaling), a good DVD player might do this better than the TV. My basic understanding is that the processing chips/algorithms by Faroudji (or others) are supposed to be good (best?), and those are typically found in mid-high end DVD players, not TV's. However...
3) I have seen a lot of posts about problems with visible Macroblocking with players using the Faroudhi DCDi chipset. MB is some watermarking technique used for DCP, :mad: and I think is only a problem over digital connections. I'm not at all familiar with this problem, and can't comment any more than this.

So in the end, does this answer your question? Not really. :confused: If you don't want to risk spending $$ and ending up with a system that is only marginally better (or maybe no better at all) than your current setup, then I wouldn't spend any $$. As for me, I will likely buy a new up-converting DVD player to go with my new Sharp LCD panel, and hook it up using HDMI, and hope for the best.

-Jay
Stryder'
I can dig that I figured that I'd just pick one up(upconverting joint ) at a store with a liberal return policy and check it out for myself

MB is some watermarking technique used for DCP
Huh?

Huh?

Uhhh, I'm out over my skis pretty far on this, but....

Isn't macroblocking is some type of digital watermark used for digital content protection on commercial DVD's?

Or not?

No.
Try a search!

No.
Try a search!

OK. I guess I was describing Macrovision. Macroblocking seems to be some type of artifact problem.

I'll try to be more correct the next time I'm trying to help another newbie that no one else will answer.

:(

If an upconverting DVD player supports DivX, does that mean it will display a hi-def DivX file at full high definition? For example, if the DivX file specifies a resolution of 1280x720, will the upconverting DVD player be faithful to that, or will it downconvert to 720x480 or some such, then upconvert from there (losing genuine information)?

If an upconverting DVD player supports DivX, does that mean it will display a hi-def DivX file at full high definition? For example, if the DivX file specifies a resolution of 1280x720, will the upconverting DVD player be faithful to that, or will it downconvert to 720x480 or some such, then upconvert from there (losing genuine information)?

There are only a few HD Divx players out there, Avel LP2, Buffulo, Snazio? -- any more guys? And I don't know if these players can play a 1280x720 Divx movie from both the disc loader and via the network port.

stryder7of9
Sorry, I was not trying to be rude. Search is a newbies best friend here.

Searching sometimes is a hit or miss thing. I think we keep getting these questions over and over since there's no database that lists key features and issues with players. I recall a thread that listed for universal players (I think), but why can't we have a master list? I know, I just signed myself up. I'd love to create it but I have a day job :o) ... maybe an advanced member could coordinate it. But really, this would be so much more useful than combing thru page after page, and reading unrelated issues, and also missing useful posts since you didn't type in the right letters/numbers. You know .... uh hum ... people don't always spell correctly. So I'm not necessarily defending this Macrovision vs macroblocking question -- I'm just thinking many people could be better served by having some sort of spreadsheet that covers features/issues/hacks.

Thanks to Bob for the awesome posts!

I've only just discovered it, and it is every bit as valid today as it was when first posted.

One thing that bothered me when progressive DVD players were the hot item years ago. IMHO the general public was not made aware that you needed an HDTV or a SDTV that accepted progressive signals to get any benefits from a progressive player! I had to find that out for myself. Talk about marketing B.S.! I almost got suckered into buying one, and it would have been a waste as my TV only took interlaced signals.

Bob or anyone, do you know if any SD CRT TVs were made that took progressive inputs? I don't recall seeing any. (I'm not talking about ED plasmas)

{/ramble}

Sorry if they were already answered...I didn't read this WHOLE thread :o

The 62 toshiba I am getting supports 1080p. Will I be able to put that to use? Are there DVD players out there that can do that or like you said are all DVDs only capable of around 480i. We don't have HD cable, but WOULD HD caple support 1080p?

I mean whats the point in having it if it can't even be used yet :confused:

Oh ya, and also what kind of DVD player would I be looking for to get the most out of my tv?

I have a 3 year old HDTV-ready set and a new upconvert DVD player with standard, component and HDMI outputs and cables. The TV, however, does not have an HDMI input jack. Previously, I owed an older DVD player (not progressive) and was connected through standard cables.

I do believe I'm seeing a better picture through the component cables but am wondering if it would improve if I could connect through the HDMI cable. If so, is there a way to adapt the HDMI cable to connect it to the TV?

Hopefully, my question makes sense to someone who could help me. Thanks!!

Now it gets even more interesting with the new crop of 1080p displays.

Do you have the DVD player upscale to 1080i and then have the TV upscale to 1080p or do you connect via component 480i and have the TV upscale to 1080p?

Which is worse, upscaling twice with no A/D conversion or upscaling once with the A/D conversion?

As for 480i vs 480p on DVDs, I simplified my first post for clarity. DVD frames from sources like film or computer imagery are indeed recorded "progressively" and the DVD data includes flags which identify whether the fields making up each frame were recorded at the same time (film based) or slightly separated in time (video based) -- flags which the player has to interpret correctly or the resulting imagery will be screwed up, as with the infamous Color Upsampling Error (CUE). But it is still best to think of the DVD data as 480i since the player has to deconstruct the film based frames into their individual fields and put them back together again slightly differently as part of raising the film frame rate of 24 frames per second to the video frame rate of 30 frames per second. Then, if the player has been asked to put out a 480p signal, it has to de-interlace that NEW, constructed, stream of data.

Remember that the DVD standard was launched back when all consumer TVs accepted only 480i signals, and that all DVD discs and DVD players today still have to support TVs that don't have progressive inputs.

By the way, 480i and 480p are essentially the same as far as storage and data rates are concerned. A 480i signal consists of one interlaced half frame (field) every 60th of a second and a 480p signal consists of a full frame every 30th of a second.
--Bob

Pretty cool thread. I'm glad to see the revision to the first page with what I quoted above, as I think it was incorrect to indicate that ALL DVD storage is 480i (in fact, many sources are now doing 24fps FILM mode storage, mostly because of the space savings you get from fewer duplicated fields to get to the 30fps telecined display).

Now, from what I can find, most DVD progressive play back is converted to 480p/60 (per this page, scroll down a couple screens: DVD encoding, Interlacing and Deinterlacing techniques (http://www.hometheaterhifi.com/volume_7_4/dvd-benchmark-part-5-progressive-10-2000.html) ) for most displays (which ends up making some fast motion video look a bit jerky, because of the 3/2/3/2 conversion from 24 to 60fps common in NTSC progressive format standards), known as 3:2 detection and inverse telecine (NOT 3:2 pull down, which is the telecine creation process).

Anyway, my question is, why wouldn't they have a way for FILM mode encoded 24fps DVD's to be played back at a 24 (or better 48fps) rate on HDTV's and avoid the conversion to 60fps? At least on digital TV's. I mean, who cares what the broad cast format/speed is, these TV's should be able to display a nice direct version of 24fps content (and if that is too much flicker, then 2x or 3x frame copy for 48fps or 72fps). But at least you get a nice even duty cycle for EVERY ORIGINAL FRAME, rather than the crap you get from converting to 60fps.

I think that would mean you would need a DVD player that you specifically "instructed" to output at 24fps (maybe HDMI/DVI conncetions negotiate this as plug-n-play and can indicate they can take a 24fps content)?

I just got a new HP MD5880N 1080p DLP TV, and am VERY curious to find out if I should be looking for a new DVD player to enable me to play DVD's that are properly encoded in FILM mode to directly sent the 24fps to the TV (as this TV lists 24fps input as supported)?

One last question: I think normal HDTV broadcast (and HD film content) is at 30 and 60fps. So, that means that ESPN hi-def is recorded progressive 60fps (maybe 30fps on some content). What is Showtime/HBO doing with movie FILM content that is 24fps to broadcast it at the standard 30fps HDTV format? The same inverse-telecine as above? No wonder made for TV original content and discoveryHD and ESPN-HD all look so much better than movies broadcast in HD...no conversion! Someone correct me if that is wrong.

TIA,

-JM

I hooked up my SA8300HD DVR both on the HDMI of my Panny 53" and through the component cables, and frankly I can't see a difference. But I use the HDMI anyway because I have the cable so might as well, and even if there is no discernible difference to my eyes, in theory at least (so I hope) the digital should be better.

See this is interesting. I thought I wouldn't be able to tell the difference between HDMI and Component on that, but I definately prefer HDMI. You've got a much larger TV though.

I just bought the Samsung DVD-HD845, which is the same as the 850 except it doesn't have the cable. Since my TV (LG DU-37LZ30) only has a DVI port and I already have an HDMI->DVI cable, I was able to save some cash.

I put the SA8300HD on component, and the DVD-HD845 on DVI (with optical audio), and I was pretty disappointed with both. I thought the HD channels all lost a little life and that eye-pop, and I thought the DVD player was horrible. I played the first 20 minutes of the Two Towers, and the picture was grainy and pixellated. I tried the same scenes on my Xbox 360 over component, and was pleased (for the record, I think that the 360 looks just fine, but the high-speed DVD drive and fans are a deal-breaker).

I switched them back, and I'm pretty happy with them now. Was I doing something wrong the first time? I did tinker with the settings in the 845's menu, but could certainly have missed something.

I also need to pickup an Avia disc. Is it possible to rent one? I've spent a ton of cash in the last month, and my bonus is running out ;-)

I have a 3 year old HDTV-ready set and a new upconvert DVD player with standard, component and HDMI outputs and cables. The TV, however, does not have an HDMI input jack. Previously, I owed an older DVD player (not progressive) and was connected through standard cables.

I do believe I'm seeing a better picture through the component cables but am wondering if it would improve if I could connect through the HDMI cable. If so, is there a way to adapt the HDMI cable to connect it to the TV?

Hopefully, my question makes sense to someone who could help me. Thanks!!

Your not alone although there are some people that deny that there are those of us that see a better picture with component. In fact, the latest Perfect Vision did an extensive review of a cross section of DVD players and ended up recomending component on all but two DVD players. This is not to say that on the right combination, HDMI can prove to be a better connection. Almost every objective thread I have read offers the same advice which is to try for yourself and you may not get better results, it is display dependent. I feel sorry for all the people who went out and bought an upscaling DVD player thinking that it would be an improvement, there were probably way too many upscaling DVD players sold that just don't measure up to a good "ol' fashioned" component DVD player.

Your not alone although there are some people that deny that there are those of us that see a better picture with component. In fact, the latest Perfect Vision did an extensive review of a cross section of DVD players and ended up recomending component on all but two DVD players. This is not to say that on the right combination, HDMI can prove to be a better connection. Almost every objective thread I have read offers the same advice which is to try for yourself and you may not get better results, it is display dependent. I feel sorry for all the people who went out and bought an upscaling DVD player thinking that it would be an improvement, there were probably way too many upscaling DVD players sold that just don't measure up to a good "ol' fashioned" component DVD player.


Pretty funny, just read through quite a bit of this thread...just got out of bed to check the inputs on my 50" Marantz plasma...there is one HDMI input and I started to think, "that sucks, wanted to hook up HDTV and new DVD player"...then I read the last post and laughed...

Good post!

All the more reason to buy a player such as the Zenith/LG DVB318 or DVB418 that, with proper firmware, can upscale through the component video output.

I don't think my upscaled component Zenith 318 looks as good as my denon 3910 over non-upscaled component video. So my ae700 must be a reasonably good scaler.
It isn't the Component video vs DVI/HDMI, it's the crap de-interlacers and scalers (and/or general crappiness) in the cheap upscaling players.

Pretty funny, just read through quite a bit of this thread...just got out of bed to check the inputs on my 50" Marantz plasma...there is one HDMI input and I started to think, "that sucks, wanted to hook up HDTV and new DVD player"...then I read the last post and laughed...

The fact of the matter is that certain DVD players have a measurably better HDMI video frequency response, compared to component. (The Onkyo SP1000 is an example of one that does.)

Because someone can't see the difference between HDMI and component on his or her particular display shouldn't be an indictment of digital transmission vs. analog, but rather an indication that maybe other components in the chain need to be upgraded to fully exploit the extra information that may be present in a purely digital signal. If you have a CRT-based or front or rear projection display, e.g., you may not notice a subtle improvement in frequency response that may be apparent on a plasma or LCD flat panel.

At minimum, HDMI should look as good as component, with the potential to look better if the right pieces of equipment are in place.

/steve

Hi List,

I have a question on some new equipment. I have a Sony KDF-E42A10 LCD projection TV and just purchased a Toshiba SD-4980SU DVD player. Both the items have HDMI connectors on then and I use that to connect the DVD player to the TV. I haven't yet used the the DVD player on the TV, been traveling, but now have a question on the audio.

If I'm going HDMI directly to the TV how do I direct my sound to the reciever (Yamaha HTR-5830) for normal and Surround sound? My tv has a Digital Audio out port? The TV manual states this port is available when the TV recieved a digital TV channel.

The DVD also has a optical out, should or could I use this for the audio to the reciever? Or am I missing something?

Thank you in advance..

Tom.

Hi List,

I have a question on some new equipment. I have a Sony KDF-E42A10 LCD projection TV and just purchased a Toshiba SD-4980SU DVD player. Both the items have HDMI connectors on then and I use that to connect the DVD player to the TV. I haven't yet used the the DVD player on the TV, been traveling, but now have a question on the audio.

If I'm going HDMI directly to the TV how do I direct my sound to the reciever (Yamaha HTR-5830) for normal and Surround sound? My tv has a Digital Audio out port? The TV manual states this port is available when the TV recieved a digital TV channel.

The DVD also has a optical out, should or could I use this for the audio to the reciever? Or am I missing something?

Thank you in advance..

Tom.

I think the TV's out is for when you tune in a cable channel, not for relaying something else from another source sent in via HDMI.

I would suggest you connect the TV's Optical out to the receiver and use that input while watching TV.
Connect another cable from the DVD player's Optical out to another receiver input and use that one to get the sound from your DVDs.

p.s. If your receiver has HDMI switching, you can probably (I say probably because it's new and not always perfect technology) use all HDMI cables instead for both video and audio. One from the DVD player, one from the TV. You'll still be selecting different inputs switching from cable to DVD, but there'll be less cabling required.

Thanks for the excellent thread. I'm in the process of figuring out what to do for my brother. He just got a Toshiba 56MX195, 54" DLP 1080p. Tried out the 480i DVD player he has had with the new TV and is unhappy with PQ. I'm going to do some work with DVE tomorrow but I have to wonder if even just buying one of the newer players with a connection better than s-video will assist in improving his picture. His new Toshiba has two HDMI ports.

Your not alone although there are some people that deny that there are those of us that see a better picture with component. In fact, the latest Perfect Vision did an extensive review of a cross section of DVD players and ended up recomending component on all but two DVD players. This is not to say that on the right combination, HDMI can prove to be a better connection. Almost every objective thread I have read offers the same advice which is to try for yourself and you may not get better results, it is display dependent. I feel sorry for all the people who went out and bought an upscaling DVD player thinking that it would be an improvement, there were probably way too many upscaling DVD players sold that just don't measure up to a good "ol' fashioned" component DVD player.

I would totally agree... and I think the many posts on problems associated with these new players prove that.

For myself, I could not tell any difference in PQ with my old sony 480p progressive scan player over component and the BBK 988 (= oppo 970) thru hdmi at any resolution.

Was a bit disappointed really as I was expecting a massive improvement. But then maybe its just my old eyes... :rolleyes:

Thanks for this thread... it cleared up some questions I had on how scaling works. Excellent writeup!

must tag the sticky

OK,

I think I understand the scaling thing, at least as far it applies to me. The thing I'm still a little fuzzy on is progressive scan. IF I have an LCD set that both scales and de-interlaces properly, can I use a normal 480i player and let my set do the de-interlacing and scaling? I'm asking if it is technically possible, not necessarily a best practice. Also, if it is possible, is it restricted to specific connector types? Again, is it technically possible.

OK,

I think I understand the scaling thing, at least as far it applies to me. The thing I'm still a little fuzzy on is progressive scan. IF I have an LCD set that both scales and de-interlaces properly, can I use a normal 480i player and let my set do the de-interlacing and scaling? I'm asking if it is technically possible, not necessarily a best practice. Also, if it is possible, is it restricted to specific connector types? Again, is it technically possible.If the LCD is a "TV", then it would be odd if it didn't deinterlace, especially if it also has composite and s-video inputs. LCD computer monitors don't deinterlace. Interlaced video is nonexistent in the PC world.

larry

I am in the same boat-have a good working 480i player and a new Panny
HDTV. If the panny can do the work of a newer progressive dvd with the
signal from my 480i, no need to update until the HD players are less money.
I hope you get a definitive answer to your question.

Your Panny will deinterlace a 480i signal from your DVD player.

larry

Your Panny will deinterlace a 480i signal from your DVD player.

larry
That's good news. Although it's a 480i player, it does have component out which I used.
The PQ was pretty darn good, and I was frankly surprised that an older DVD player could output that nice of an image. Now the extra bucks can be saved toward a HD player in the future.

first of all let me tell you that i read the 1st page and didn't read the rest. BUT, I want to thank Bob for his very clear explanations.

Now, I have a toshiba sd-5980 (up-converter) dvd player and a panny th-42phd8uk plasma tv (connection is hdmi via 7 series blade). My question is a general one I think:

after using the hqv benchmark dvd for 480p, 720p, and 1080i; I decided that 720p is the optimum combination for my components (got the best score from my eyes). And as far as I understand for regular dvd content this is my dataflow:

480i (720x480) >> 480p (720x480) >> 720p (1280x720) (up until here everything was done via dvd player) >> 768p (1024x768) (tv scales the image to its natural resolution)

1) So, which one is a more complex process (and why):

i) converting from 1280x720 to 1024x768, OR
ii) converting from 720x480 to 1024x768

I am asking because if, indeed, the first process is less complex I can get a better understanding up-scaling dvd player concept.

2) What do you look for (like artifacts or crispness or natural colors, etc.) to tell whether a dvd player's scaler is better than tv's? (it might be subjective but i would like to get some ideas).

Thanks kindly...

first of all let me tell you that i read the 1st page and didn't read the rest. BUT, I want to thank Bob for his very clear explanations.

Now, I have a toshiba sd-5980 (up-converter) dvd player and a panny th-42phd8uk plasma tv (connection is hdmi via 7 series blade). My question is a general one I think:

after using the hqv benchmark dvd for 480p, 720p, and 1080i; I decided that 720p is the optimum combination for my components (got the best score from my eyes). And as far as I understand for regular dvd content this is my dataflow:

480i (720x480) >> 480p (720x480) >> 720p (1280x720) (up until here everything was done via dvd player) >> 768p (1024x768) (tv scales the image to its natural resolution)

1) So, which one is a more complex process (and why):

i) converting from 1280x720 to 1024x768, OR
ii) converting from 720x480 to 1024x768

I am asking because if, indeed, the first process is less complex I can get a better understanding up-scaling dvd player concept.

2) What do you look for (like artifacts or crispness or natural colors, etc.) to tell whether a dvd player's scaler is better than tv's? (it might be subjective but i would like to get some ideas).

Thanks kindly...
bump
would also like to know

Use which looks better to you. Upscaling and downscaling are equally hard/easy. Scaling twice, in general, is not a good idea, but the proof is in the pudding. With digital video there shouldn't be any difference in color between players or resolution on a given display. The color is encoded on the disc. If there is a difference, one (or both) is doing something wrong. Once the display is calibrated to the player/resolution, color should look the same. On a small display like yours you'll problaby be hard pressed to see any difference between the 2 resolutions.

larry

which one is a more complex process

Well, it depends. Downscaling throws away information. Upscaling doesn't add information, but can sometime extract and better use information which was not visible in a lower-res image, especially if there is access to the original mpeg stream (as in your dvd player). Any scaling can introduce imaging artifacts, but can also clean the signal/remove noise, sometimes to a remarkable extent. The NSF supports many PhD mathematicians and engineers who work on image analysis full time, the issues and tradeoffs are extremely complex, I think more so than page 1 of this thread might suggest.

Larry's instructions to trust your eyes is not frivolous, since it is unlikely one has enough information or expertise for any particular equipment combination to calculate an answer from specs alone. - DR

We had a Zenith 32" CRT HD set and it bit the dust last week. We bought a 37" Magnavox LCD set to replace it. We have a 6 year-old Pioneer 480i DVD player. It looks good on the Magnavox. But I'm wondering if an upconverting player will look even better on my new set. Any thoughts?

Any thoughts?

Sure! Read the other posts!

You'll see that it completely depends upon the combination of DVD player and HD set. Borrow <ahem> one from a store (or a friend) and try it out. If you like it...buy it...if you don't...try a different one. The larger the display, the more that you'll notice the difference (or not). On displays under 34-37" you'll be less likely to notice the difference at normal viewing distances. On some you'll notice a slight quality lift on others you may actually see the upscaled picture looking far worse.

We had a Zenith 32" CRT HD set and it bit the dust last week. We bought a 37" Magnavox LCD set to replace it. We have a 6 year-old Pioneer 480i DVD player. It looks good on the Magnavox. But I'm wondering if an upconverting player will look even better on my new set. Any thoughts?

Upconverting players usually work well with LCD and plasma. I replaced my 4 year old 480p DVD player with an inexpensive HD upconverting player, on my 42" plasma the upconverted 1080i via HDMI is noticeable better in PQ. At least you should try it with a good upconverting players (Oppo, Panny, Sony...etc), most likely the PQ will improve due to upscaling and HDMI digital to digital connection.

first of all let me tell you that i read the 1st page and didn't read the rest. BUT, I want to thank Bob for his very clear explanations.

Now, I have a toshiba sd-5980 (up-converter) dvd player and a panny th-42phd8uk plasma tv (connection is hdmi via 7 series blade). My question is a general one I think:

after using the hqv benchmark dvd for 480p, 720p, and 1080i; I decided that 720p is the optimum combination for my components (got the best score from my eyes). And as far as I understand for regular dvd content this is my dataflow:

480i (720x480) >> 480p (720x480) >> 720p (1280x720) (up until here everything was done via dvd player) >> 768p (1024x768) (tv scales the image to its natural resolution)

1) So, which one is a more complex process (and why):

i) converting from 1280x720 to 1024x768, OR
ii) converting from 720x480 to 1024x768

I am asking because if, indeed, the first process is less complex I can get a better understanding up-scaling dvd player concept.

2) What do you look for (like artifacts or crispness or natural colors, etc.) to tell whether a dvd player's scaler is better than tv's? (it might be subjective but i would like to get some ideas).

Thanks kindly...

Ahh. Very well put question. Must be an engineer;-) I have been wondering the same thing. Did you get an answer yet? Given that your TV must still do one last step of scaling, which does it do the best: 480 to 786, 720 to 768, or 1080 to 768? THis is an interesting question. There is the same amount of information in all three, down scaling DOES NOT reduce information as stated previously (At least not if it's done properly. You can't just discard entire lines. In any up or down conversion every output pixel can be a function of every input pixel. It ia a lot more complicated than just sub sampling).

Now even if we do answer the about question, we still need to know which unit is a better scaler, the dvd player or the TV. You mentioned the dvd test disk. Is this really usefull to answer the question of which output signal works best? How does it work?

I have the Panasonic plasma 50PH9UK and a Sony 75H dvd player. Which scaler is better? What chipset does the Panasonic use? How about the Sony?

Thanks
Rich

There is the same amount of information in all three, down scaling DOES NOT reduce information as stated previously.All else equal, it does. For example, if a displayable 1366x768 image is converted to a displayable 1366x720 image, there is no algorithm that can perfectly reproduce the original 1366x768 image (just from the display image, without using collateral information).

However, in this case we are talking about converting from 1024x768 to 1280x720 and back again, which is a whole different matter - the `downscaled' 1280x720 image actually contains more pixels than the 1024x768 image, so it is perfectly possible in theory that conversions 1024x768 image-> 1280x720 image -> 1024x768 image exactly reproduce the original image. This assumes however that the information in the extra lines is somehow spread out into the extra horizontal space in such a way that it can be recovered in at the next stage...in practice, this is not what happens. - DR

All else equal, it does. For example, if a displayable 1366x768 image is converted to a displayable 1366x720 image, there is no algorithm that can perfectly reproduce the original 1366x768 image (just from the display image, without using collateral information).

However, in this case we are talking about converting from 1024x768 to 1280x720 and back again, which is a whole different matter - the `downscaled' 1280x720 image actually contains more pixels than the 1024x768 image, so it is perfectly possible in theory that conversions 1024x768 image-> 1280x720 image -> 1024x768 image exactly reproduce the original image. This assumes however that the information in the extra lines is somehow spread out into the extra horizontal space in such a way that it can be recovered in at the next stage...in practice, this is not what happens. - DR

I'm talking about a signal that originated from a dvd. This means its total information maximum fits into a 480i signal. There are 240 lines every 1/60th of a second. Scaling this up to 1080 at the dvd player adds no new information. Likewise scaling this 1080 at the TV back to 768 removes no information.

You make a good point though that I am talking about perfect scalers here. I should say "in theory" the scaling up/down does not remove any signal information, but in reality imperfections in the algorithm can cause degradation in *both* directions. I guess this is the difference we are talking about on this thread: good scalers vs bad scalers. Can we agree that a cascade of "ideal" scalers would not cause any picture quality deterioration in this case?

Now my question is which equipment should I let do each of the jobs. I have a dvd source that is 480i, and I want to display this on a monitor that is 768p. Here are some options using the upconverting dvd player.

(1) set the dvd player at 480i and let the TV do all deinterlacing and scaling. (Note this would require me to use analog signal path)

(2) set the dvd player to either 480p or 720p and let the TV do remaining scaling to 768 native resolution. The TV does no deinterleaving at all in this case.

(3) Set the dvd player to 1080i and let the TV do deinterlacing and scaling down to 768.

If I buy the HQV benchmark dvd will I be able to evaluate these combinations?

Thanks
Rich

Just purchased a PD5070 + an upscaling DVD player (Samsung HD860) + upgraded to Tivo HD Series 3 (using cable cards). What is the best way to hook up the equipment. My Sony receiver is 6 years old (has optical input) but that shouldn't be an issue even though it doesn't have HDMI inputs. I'd appreciate the help!

Thanks.

I'm talking about a signal that originated from a dvd. This means its total information maximum fits into a 480i signal. There are 240 lines every 1/60th of a second. Scaling this up to 1080 at the dvd player adds no new information. Likewise scaling this 1080 at the TV back to 768 removes no information.

Again, there are some subtleties. The image as upscaled by the DVD player contains both the original information and some added - rightly or wrongly - by the DVD player. If you then downscale in the TV, you certainly do throw away some information, and while in an ideal world it would be throwing away only information that was added by the DVD upscaler, in practice the downscaler cannot discriminate between real and added information, and you lose a proportion of both.

I don't mean to be pedantic here, but I think blurring these distinctions will cause us to miss something important. Just think about reversing the order: if you take your 480i DVD image, then downscale then upscale, that is far worse then the upscaling-then-downscaling we typically do. Just counting the number of times the image gets rescaled is not a good measure of quality deterioration.

Most of the people in this forum who report improvement in upscaling seem to end up scaling to 1080i in the player, then letting the TV scale to native resolution (which - again - is not really a downscale). This is true even though 720p for a HD signal is generally better than a 1080i signal, and also reinterlacing the signal seems like a it should make things worse. I have no clue why 1080i should ever be better, though it certainly is for many people.

Finally, as for evaluating whih is best, a good calibration DVD will have some PQ patterns which will help you decide -- if you can't tell the difference on the patterns and samples in DVE or Avia, then it doesn't really matter which resolution you use! - DR

Again, there are some subtleties. The image as upscaled by the DVD player contains both the original information and some added - rightly or wrongly - by the DVD player. If you then downscale in the TV, you certainly do throw away some information, and while in an ideal world it would be throwing away only information that was added by the DVD upscaler, in practice the downscaler cannot discriminate between real and added information, and you lose a proportion of both.

I don't mean to be pedantic here, but I think blurring these distinctions will cause us to miss something important. Just think about reversing the order: if you take your 480i DVD image, then downscale then upscale, that is far worse then the upscaling-then-downscaling we typically do. Just counting the number of times the image gets rescaled is not a good measure of quality deterioration.

Most of the people in this forum who report improvement in upscaling seem to end up scaling to 1080i in the player, then letting the TV scale to native resolution (which - again - is not really a downscale). This is true even though 720p for a HD signal is generally better than a 1080i signal, and also reinterlacing the signal seems like a it should make things worse. I have no clue why 1080i should ever be better, though it certainly is for many people.

Finally, as for evaluating whih is best, a good calibration DVD will have some PQ patterns which will help you decide -- if you can't tell the difference on the patterns and samples in DVE or Avia, then it doesn't really matter which resolution you use! - DR

Sorry, but you are confusing "information content" with "number of lines". It is a difficult concept but an importand distinction. Basically, "no information loss" is what is experienced in lossless compression. Think of it like this, if you have a single RBG pixel that is completely defined as a function of its neighboring pixels (i.e., by scaling/interpolating/deinterleaving, then that pixel contains no new information about the image, and you can discard it anytime without any impact on the video bitstream because it can be recreated again at any time as long as the neighbors are preserved. Now upscaling is like this but can be much more complicated. In theory, all output pixels can be a function of all input pixels, so each one can contain a little bit of information about the others. If someone designs a down scaler that operates by simply discarding some of these, well that's just plain stupid and will definitely throw away information as you said, but if you know the algorithm used to upscale in the first place, you can reverse the process in a lossless manner.

Of course, there will always be losses due to to the algorithm not being perfect, i.e., coefficient truncation, imperfect filter response.

Rich

Sorry, but you are confusing "information content" with "number of lines". No, I am not. You would be correct if what was being sent from device to device was a more general mathematical description of the picture from which the picture is rendered (maybe bundles of wavelets), but what is actually being sent is color level data at the pixel level. You are positing the existence of a function from an MxN dimensional space onto an M'xN' dimensional space which is both well-behaved (in the sense that it takes a viewable picture to a viewable picture) and invertible (so that you could de-scale and recover the original picture), and this is not going to happen, just as there is no differentiable bijection between Euclidean n space and Euclidean m space when n!=m. (The stumbling block here is the 'onto' condition on the function - if your downscaler could always assume that the image it was looking at was upscaled from a particular resolution, then it might be able to recover the original image.)

To make this clearer, consider the interval [0,1) on the real line, and the unit square [0,1)^2 in the plane. There is an invertible bijection between these two sets (just interleave/deinterleave decimal expansions), but it cannot take nearby pojnts to nearby points, so a set in [0,1) would be transformed into something that looks completely different. You can map [0,1) onto [0,1)^2 or vice versa in a continuous way (a so-called Peano Curve), but not invertibly.

My apologies to anyone in this thread who just wants to know where to do the scaling - perhap this discussion will convince people to follow the good advice to just try the different approaches and go with what you like! - DR

So if I have an upconverting DVD player that can do 480i,480p,720P,1080i through HDMI, and I have a 1080P TV, which, in theory, should be the best output from the DVD player?

My question, if I have a 1080P, 120hz, 4ms, 52" LCD panel with a good processor, is their any reason to buy a 1080P upconverting player???

The DVD player I have now is a JVC. Component and Opt out, Dolby 5.1., BUT NO PROGRESSIVE SCAN! Does anyone know if their would be a real benifit to going to a 1080P upconverting DVD player??

Thanks for your help.

I guess the big question is - have you read the threads in this group? Most people don't - but they may be of interest to you.

Personally, I think that you'll find that even a lower priced dvd player with and HDMI out doing 480p would be a nice improvement; however, you really need to see this for yourself. Personally, I'd wait another year before buying a 1080p machine (see which way the wind is blowing with HD-DVD/BlueRay etc...and, of course, the price lowering effect of mass merchandising). Otherwise, buy an Oppo DVD player - it won't break your bank account and you should be quite pleased with the result.

I guess the big question is - have you read the threads in this group? Most people don't - but they may be of interest to you.

Personally, I think that you'll find that even a lower priced dvd player with and HDMI out doing 480p would be a nice improvement; however, you really need to see this for yourself. Personally, I'd wait another year before buying a 1080p machine (see which way the wind is blowing with HD-DVD/BlueRay etc...and, of course, the price lowering effect of mass merchandising). Otherwise, buy an Oppo DVD player - it won't break your bank account and you should be quite pleased with the result.

Thanks N'Yeti. I have read the threads but most don't address the newer upconverting processors in the 1080P panels. I understand that one advantage is giving the panel a digital feed form a new player, which my old one can not do. I agree about waiting a year or so if I can live with this one though.

Thanks again.

The question is does your LCD do better video processing than a DVD player. Cant it deinterlace 480i better? If not, can it scale 480p to 1080p better?

larry

I came here looking for some info about upscaling DVD players, and found I may have more answers than questions. I'm an engineer, and I've been designing video circuits for the past 15 years or so.

From my experience, the first thing to always avoid in any scaling operation is scaling ratios that are near 1:1, such as 1:1.1. Even with a great scaler, this will result in noticeable loss of detail (picture gets blurry). The first shock I had was when I bought a 720p HDTV LCD, and found that it will rescale a 720p input signal to the 768 vertical resolution of the panel. This is very bad. It would be much better to have a thin 24 pixel tall black band at the top and bottom and leave the image unscaled. I've seen 720p broadcasts on a native 720 projector, and it looked much much sharper than the rescaled 768 high image on the LCD (what, you say, a projector looking sharper than an LCD?). I don't think the LCD was using a bad scaler, either, just a bad scaling ratio at 1.07:1. Scaling ratios at 2:1 or more will avoid the scaling ratio problems.

Also, it is generally bad to do a number of scaling operations one after the other. It is best to do a single rescale from source resolution to display resolution, in one step. Each scaling step results in some loss of information, usually described as 'blurring'.

So, how does this relate to upconverting DVD players? Well, I was looking for a comparison of using 480p from 'any old' DVD player to using an upconverting player that matches its output to the display resolution. So, in the first case, the DVD player does no scaling, and the TV does all the scaling (once). In the second case, the DVD player does all the scaling (once). Of course, all 768 resolution displays have the problem described above, so I am moving on to a 1080 LCD to avoid that problem (of course, there's an overscan problem with 1080, but that is another can of worms). If the scalers were equal in fidelity, and the interconnect lossless (digital), then there should really be no difference at all. And if this were true, then an upconverting player would be a waste of money.

However, as an engineer, I do know that it is POSSIBLE for the DVD player to do a better job. If I designed the player, I would do the upconversion during the inverse DCT decoding of the MPEG stream. In other words, I would decompress from the frequency domain data (that is recorded onto disk) into a higher resolution spatial data (higher than 720x480). This will result in both a higher resolution image (technically, oversampled from the compressed data) as well as introduce oversampling artifacts. However, careful filtering of the resulting image can remove most of the artifacts while producing an image that is actually higher resolution than 720x480, not just upscaled. The technical reasons why this is possible requires a detailed understanding of the DCT transform used in MPEG compression, and is way beyond the scope of this post. As far as I'm concerned, this is the RIGHT way to do upconversion in the DVD player, and it will be able to outperform the simple upscaler in the TV.

However, I am not aware of any DVD players that actually do this. If someone has some spare time (and the technical background), they can modify some MPEG decode software to upscale during the inverse transform (by zero padding the DCT data into a higher resolution matrix?). The idea is you take each macroblock, for example, and decode it directly into a macroblock with, say, 4X the resolution, with all of the original frequency components fully represented in the larger macroblock. This will, of course, introduce oversampling artifacts, and the filtering for this will be the magic that makes it work well. The end result should appear to have higher resolution than the simple upscaled version. And, in fact, the image will contain more accurate spatial content than the upscaled version. In some cases, it might even make a regular DVD look like an HD-DVD. And, of course, there will always be certain images or test patterns that will look like hell with this type of resolution recovery/enhancement.

So, can someone please design, manufacture, and sell my conceptual upconverting DVD player, so I can buy it? Faroudji? Anyone?

So... here's my dilema.

I read the post, I understand. I have last year's 56" Samsung DLP w/LED driver (HL-S5679W I think?). It'll take a 1080p signal in.

So, what do I give it? A normal 480p signal and let it upconvert it? Buy a $100 upconverting DVD player and feed it native 1080p? Buy a $220 DVD player and feed it 1080p? Whose conversion would be "cleaner" per se, the DVD's or the TV's?

And... would I notice any difference whatsoever??

Interesting discussion. I have a PJ that has a native image of 1280x768 (WXGA). I love the picture. I am considering purchasing a Denon 3930ci because it will scale to 1280x768. Doesn't this solve the problems you are mentioning? The DVD player scaling to the native resolution of the PJ.

Marcus

I would decompress from the frequency domain data (that is recorded onto disk) into a higher resolution spatial data (higher than 720x480). Aren't DVDs interlaced? I am under the impression that sequential frames are interlaced, so 60 fps is converted to 30 fps, with alternating frame data per horizontal line. Then, the DCT is applied to this interlaced frame.

If this is the case, then an IDCT into a higher resolution could cause information from one frame to be rendered into another, no? Then, when these higher-resolution frames are sliced up during de-interlacing, each frame would have fragments of the other frame visible in it. This could produce strange artifacts that would worsen the quality during motion.

Perhaps if you applied an IDCT into a higher resolution *per scan line*, to increase fidelity of the horizontal resolution, but prevent any vertical 'blending' between scanlines *where motion is present*. May involve combining two different IDCT operations at standard and higher resolutions. That would probably cause less artifacts, but I have a feeling there would still be some.

I can also see the MPEG data being used to improve motion detection for deinterlacing algorithms. I'm no expert however.

Hmmm... I was pretty sure that DVDs were not interlaced. <shrug>

Hmmm... I was pretty sure that DVDs were not interlaced. <shrug>
I believe they're 480i (interlaced) natively, and anything "progressive scan" processes a 480i signal and outputs 480p (or 720/1080/etc, depending on the model)

Here, more than you ever wanted to know about it :D http://www.hometheaterhifi.com/volume_7_4/dvd-benchmark-part-5-progressive-10-2000.html

So... here's my dilema.

I read the post, I understand. I have last year's 56" Samsung DLP w/LED driver (HL-S5679W I think?). It'll take a 1080p signal in.

So, what do I give it? A normal 480p signal and let it upconvert it? Buy a $100 upconverting DVD player and feed it native 1080p? Buy a $220 DVD player and feed it 1080p? Whose conversion would be "cleaner" per se, the DVD's or the TV's?

And... would I notice any difference whatsoever??

these are exactly the same questions i'm asking myself....but for a Sharp 46D64.

I just got a Pioneer PRO150FD and VSX92TXH, and I'm leaning towards NOT getting a 1080p uscaling dvd player, because both the display and the receiver already do that, and I dont see a standard def DVD player doing it any better.

So, unless someone has a good reason why I shouldn't, I'm going to get a non-upscaling DVD player. That said, can anyone recommend a good non-upscaling DVD player that isn't a total dinosaur and sends a good quality feed for my other components to make pretty?

I just got a Pioneer PRO150FD and VSX92TXH, and I'm leaning towards NOT getting a 1080p uscaling dvd player, because both the display and the receiver already do that, and I dont see a standard def DVD player doing it any better.

So, unless someone has a good reason why I shouldn't, I'm going to get a non-upscaling DVD player. That said, can anyone recommend a good non-upscaling DVD player that isn't a total dinosaur and sends a good quality feed for my other components to make pretty?

Do they make non-upconverting players anymore?

It is an option -- you get to choose your output resolution. An upconverting player at 480i or 480p is not upconverting.

I've been happy with my Oppo players.

-Bill