20 x 9 anamorphic...HD-DVD could make it happen...

Go to greg's site (bravo Greg!) and scroll near the bottom where the heading "20:9 Anamorphic" is and read:
http://gregl.net/videophile/anamorphic.htm

Apparently just as the 16x9 aspect ratio is part of the MPEG2 standard, so is the ability to encode movies in a 20:9 aspect ratio frame...as well as the ability to downconvert every 5 lines to four (for 16x9 displays) and every 5 lines to 3 (for 4x3 displays) just as current DVD players can downconvert every 4 scan lines to 3 for 16x9 video on 4x3 displays.

This would increase the resolution of 2.35:1 transfers by 67% over 4x3 encoding rather than just the 33% that 16x9 offers. That's a significant gain, and continuously-variable displays like CRT front projectors, or displays that have vertical resolution to spare could really benfit. Displaying a 480P SD-image of a 2.35:1 film in 20:9 mode would give you almost as many scan-lines as the same image in 720P in 16:9 mode! (naturally, a 720P or 1080I/P 2.35:1 image in 20:9 mode would be the best).

The 20:9 encoding feature, if utilized for future HD-DVD, would abosolutely push the limits of perceived resolution.

This is not so weird. The digital projection of Star Wars Episode One was "HD" resolution in the sense that it had 1080 (said to be interlaced) lines of resolution. But it used nearly all of those scan-lines to encode the vertical resolution of the 2.35:1 image of Star Wars. The "anamorphic" 2.35:1 HD image was unsqueazed through an anamorphic lens for projection. Even with reported interlaced scanning, most people who've seen the digital projection said it looked significantly superior to film. That's the resolution we'd have if 2.35:1 HD-transfers were released with 20:9 anamorphic encoding!

What I'm suggesting is that the same level of vertical resolution could be acheived by using the 20:9 aspect-ratio feature of future HD-DVD's. The conversion software could easily be incorporated into all HD-DVD players from the get-go gauranteeing (sp?) backwards-compatibility with 4x3 and 16x9-480 limited displays.

What do you guys think? I think we should start to create discussion about 20:9 encoding NOW so that the manufacturers, mastering studios, and DVD forum start thinking about it before the first-generation of HD-DVD players hits the market. Incorporating DTS into DVD-players after-the-fact would have been a day-at-the-beach next to trying incorporating something like 20:9 anamorphic compatibility once HD-DVD is developed and moving along. All those glorious 2.35:1 HD-transfers Colubia is doing could contain significantly more resolution if they were being encoded 20x9 rather than just 16x9.

HD-DVD may be the best resolution-format we ever get to "buy" our movies on. I'd like it to feature 20:9 encoding for my 2.35:1 films to capture them with as much image fidelity as possible.

-dave

[Colin Dunn]

If the feature is in the specs, I say: USE IT! There is a caveat: Does the existing installed base of SD-DVD players know how to downconvert 20:9 for showing on 4:3 or 16:9 displays? I doubt it, as this feature just isn't very well publicized...


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Colin Dunn
DDS-006

Dave,

20:9 looks like a good idea, but one big flaw is that most all DTV capable displays including computer monitors, RPTVs and FPTVs don't have the range of vertical size adjustment to squeeze the picture to nearly half the 4:3 height necessary for proper 20:9 reproduction.

It could be done with anamorphic lenses for RPTVs and FPTVs, but it wouldn't be cheap.
And it would only benefit 2.35:1 format films.

-Dean.

It's not something that's part of the SD-DVD spec...but it's part of the MPEG2 spec. This means it [i]could[/i[ have been made part of the standard DVD spec, and that it can be made part of the HD-DVD spec.

As far as HD-DVD goes, let's keep in mind that we're just looking at the first-wave of entry-HDTV's. They don't even do 1080 Progressive-scan...which many high-end front-projection systems can do (what a line-quadrupler pretty much gives you).

Also, just like anyone can make a 4x3 do the "sqeeze" trick for 16x9 video...which some manufacturers are finally making a factory-intalled feature, the same is true for showing 20:9 video on a 16 x 9 set. An HDTV could just do the "sqeeze" trick and wha-la! As long as the beam-spot size isn't comprimised, you'd get an outstanding picture.

But where this would really shine is with high-end front projection systems. On a 12" screen the loss of resolution with 2.35.1 films...even the ones that are 16x9 encoded...will make 20x9 encoding a great benefit.

Just to remember all HD-DVD players could be equipped to downconvert 20x9 video to 16x9 and 4x3 just the way today's SD-DVD players downconvert 16x9 video to 4x3.

-dave

Catch my goof there with itallics? Hey! I'm learning

-dave

[Chromy]

I would say that this would be something for HD-DVD to use, assuming a couple of things:

HD DVD comes out pretty late in the game... when a lot of people have 16X9 television screens, and these televisions can compress the scan lines this much.

The hardware people find a better way to do downconversion. throwing out 2 of every 5 lines is almost every other line. That is alot of missing information, and downconversion artifacts will be rampant.

Chromy

I agree that 16x9 TV's having the ability to compress the image for a 20x9 source is important. Of course, anyone with a front-projection CRT set-up could do this (they can do this now) without a problem--and it's on large-screen (measured in feet not inches) where the added resolution of 20x9 for 2.35:1 films will make a real difference.

But regarding "rampant" downconversion issues. Yes, I'm sure we need better downconversion software!

However...we shouldn't get into a mode that thinks throwing out scan-lines automatically results in artfacts. Know all those 16x9 anamorphic DVD's from Colubuia you own? They were all downconverted from HD-masters. In other words, they started out with 1080 horizontal lines and were downconverted to 480 horizontal lines. They also happen to be the best-looking DVD's out there.

The key is how you downconvert (I'm just so excited to finally know how to itallicize and bold-face). If the software just "throws out" 2 out of every five scan-lines, you're right. We'd get some serious artifacts. Hopefully those 1st-generation-Toshiba days are over!

But if the player recalculates three new scan-lines from every existing five, you could actually get an image superior to a straight-4x3 transfer! Besides, if we're talking going 20x9 HD to 4x3 NTSC, you're actually downconverting from 1080 to 480 anyway...the 20x9 encoding would just give software more lines to work with during calculations and should result in a superior to image to a "straight" 16x9 HD -> 4x3 NTSC image anyway.

Some of the new SD-players are doing a pretty good job with folding 4 lines into 3. Hopefully some of the "high-end" manufacturers will learn from this for the future, and if 20x9 HD-encoding becomes a reality, they could provide videophile-grade conversion software.

Of course, I'm sure those of us who care the most will have 16x9 displays for our HD-DVD collection, which would only necessitate folding 5 lines into 4 (no biggie) for those with displays not equipped to display 20x9 in full res.

-dave

Dave,

I still have a problem with the vertical height control limitation.

I haven't seen any monitors, RPTVs or FPTVs that allow a 40-50% reduction in vertical height of the picture to format the 1.33:1 image to 2.2/2.35:1. The max on most all displays is 25-33%.

So it wouldn't work with any the current equipment out today.

Also the spot size would have to be miniscule to take 720p or 1080i and cram it into 3/4 or half of the height. Most likely you would get overlapping scan lines which would make the picture fuzzy and not benefit for the extra resolution.

I don't think that the downconversion would be too much of an issue as this technology is advancing rapidly.

Even though I'm skeptical about the feasability of 20:9 formatting, it would be an oversight not to support it if they are developing HD-DVD specs. It's just like including 1080p in the ATSC specs, because broadcast 1080p could happen someday.


-Dean.

Dean,

I'm with you that it would be pretty hard to imagine a 4x3 monitor sqeezing all those scan-lines into a 20x9 window without some overlapping. That's where a little downconverting would come in. You could set the output of your HD-DVD player to 16x9 and have it downconvert 20x9 discs for display on your 4x3 set with a 16x9 mode. No matter how you slice it you come out a winner.

But what about a 16x9 HDTV with a 20x9 "sqeeze" mode? That would be approximately the same amount of "sqeezing" that you get when a 4x3 monitor sqeezes for 16x9. Depending on beam-spot size and interlace vs progressive-scanning, that could look quite impressive on a big-screen RP HDTV.

Just to repeat, the biggest advantage of this encoding is for large front-projection systems that are trying to duplicate cinema proportions in your living room. With CRT front-projection devices, you could just as easily widen the image to unstretch a 20x9 image and leave the vertical height...and the optimaized beam-spot-issue...alone.

That's what many high-end home theaters try to do now with "constant height/vary width" screens. Rather than watching 2.35:1 films "letterboxed" on a 16x9 screen, they zoom in so that the 2.35:1 image fills the height area of a 1.85:1 transfer, and then widen the image keep it in tact. The result is the same sort of aspect-ratio variation that takes place in a real theater...with all images (including 1.33:1 and 1.66:1) maintaining the same height and only varying in width. That's the ultimate in home-theater...necessitating no loss of impact with aspect-ratios wider than 1.85:1!

In these installations, the added resolution of 20x9 encoding would be dramatic...even with HD-source material. It's also the approach HD-projection will take for theaters (using the full-range of vertical pixels to record the image in HD even if the image is wider than 16x9). Why let the theater get a 1080-line HD transfer that has 30% more resolution than your HD-DVD version?

In any case, agreed that the spec should get written into the HD-DVD format so we won't be dreaming of what could-have-been once HD-DVD is here and we're ready to shine it on our Ray-Bradbury TV wall.

-dave

Dave,

I like your idea of increasing the width.

But after playing many hours with my FPTV, I still don't think that there is enough adjustment availble with regular CRT displays for 20:9, even combining both vertical and horizontal adjustment.

With my graphics-grade FPTV, I can barely span the sizing gap between 1.33:1 framing and 1.78:1 framing alone. At 1.33:1 my horizontal width is at zero, and my vertical height is at 2 (on a scale to 10). When set up for 16:9 enhanced DVDs, my horizontal width is set to 9.5, and my vertical height is set to 0.5 (at 1024 X 768p@72Hz), so I have no more adjustment to make in width or height if a 2.35:1 film was vertically extended in a 1.78:1 frame.

Also there are further considerations to be made with non-anamorphic material that needs the vertical height extended to 6 or so to get a full 16:9 screen image height with letterboxed DVDs.

And the situation is harder with 16:9 RPTVs because they have vertical blanking, or 16:9 masking on their 4:3 CRTs that limit any adjustmant of vertical image space.

I'm not a video design engineer, so I can't say why there is only around 25% vertical and 25% horizontal adjustment on CRT displays, but there is. And a 20:9 format specification would need to get past those design/physical limitations to work.

-Dean.

Wow...two people having an intelligent discource about DVD/HDTV issues on the internet? It can be done!

I like your idea of increasing the width...But after playing many hours with my FPTV, I still don't think that there is enough adjustment availble with regular CRT displays for 20:9, even combining both vertical and horizontal adjustment.

What projector do you have? I'm aware of several people with home theaters I've read about on the internet who are able to display native 16x9 video with good-scan-line density, and then widen the image (and blow up the veritcal sizing) so that 2.35:1 films maintain the same height as the 1.85:1 image. What 20x9 would do is let you simply widen it (which these people are already doing) but leave the scan-line density the same (optimal) as it is with native 16x9 video.

Obviously, whether a proctor has enough flexibility with height/width adjustment to properly display a native 20x9 image is dependent upon its design. Also, once a projector has been calibrated for it's optimal scan-line density, whether it can then widen it's image beyond the 16x9 width enough to accomidate a 20x9 aspect ratio is dependent on the design of the device (the finer the beam-spot-size the greater this possibility). I believe one of the home-theaters I read about is using Runco's top-CRT projector (and Faroudja line-quadrupler). But there aren't any laws of physics preventing it. It's just a matter of design and beam-spot-size.

Also there are further considerations to be made with non-anamorphic material that needs the vertical height extended to 6 or so to get a full 16:9 screen image height with letterboxed DVDs.

Naturally. But I'm going to assume that at that stage-in-the-game your HD-DVD player or scan-converter (or both,if they're in the same box) can recalculate 4x3 LBXed material to "fake" 16x9 adding in a new fourth line for every three. This is what a few Faroudja processors do as well as many PD-DVD-ROM set-ups and it provides superior results to the old-fashioned "blow up" method.

If you didn't have this "anamorphic upconversion" feature the worst it would mean is that you optimize your display's scan-line density of native 16x9 (and poss 20x9) video and you have to spread those lines apart a tad to accomidate 4x3 lbxed encoded material.

And the situation is harder with 16:9 RPTVs because they have vertical blanking, or 16:9 masking on their 4:3 CRTs that limit any adjustmant of vertical image space.

That's why the spec provides two downconverion algorithms: one for translating 20x9 video to 16x9lbx, and one for translating 20x9 video to 4x3 lbx. I mean, that's what we do now with 16x9 video for 4x3 displays that aren't 16x9 compatible.

I'm not a video design engineer, so I can't say why there is only around 25% vertical and 25% horizontal adjustment on CRT displays, but there is. And a 20:9 format specification would need to get past those design/physical limitations to work.

Niether am I But I've read descriptions of home-theaters that not only seem capable of doing it, but apparently aredisplaying 1.33:1 -> 2.35:1 films all at constant height/varying width...and with a beam-spot-size that's not overlapping when the lines are most condensed (as in the case of today's native 16x9 and 4x3 full-frame material).

Certainly, with the advent of digital projection in theaters utilizing this very sort of projection technique, even if not every current projector is capable of a 2.35:1 image using nearly all it's 1080 active lines of picture, this technology is sure to trickle down to the consumer. I think that's digital-projection's greatest reward to the videophile...not just the image quality we'll get in the theater, but the incredible front-projection technologies that will influence the design and cost of consumer equipment!

And here's the final thought to all this:

1. it doesn't matter if a particular display can't do full 20x9 1080 because that's what downconverion sampling is for.

2. Ultimately when scaling processing software becomes reasonably affordable, every projector will probably be left in one native scan-rate/resolution and a digital "scaler" (like the Snell & Wilcox scaler) will convert everything to that optimal spec. (this is already the case with fixed-pixel displays such as plasma, DLP and LCD displays). In such a case there's no need to worry what-so-ever about overlapping scan-lines or anything else. The rule of thumb would simply be that the more resolution you provide your scaler with to do it's calculations, the better looking the final image would be. With digital fire-wire conecting all your video devices, the quality is sure to be first-rate.

3. 20x9 1080 (of films approx 2.22:1 or wider) would provide the best inherent resolution within the MPEG2/HDTV specifications. What you do with it once you take it off the disc is up to you. Let's go for it!

-dave

Ah Ha! More good points!

---What projector do you have?

I have an Electrohome Graphics CRT FPTV.

And I will concede that with a 10' wide 16:9 screen, I am already at the maximum image size of the projector, and a smaller screen size might give me a little more leeway, but I still doubt that I could find another 25%.

---I believe one of the home-theaters I read about is using Runco's top-CRT projector (and Faroudja line-quadrupler). But there aren't any laws of physics preventing it. It's just a matter of design and beam-spot-size.

Well, I am agreeing with most of your points mentioned, but I think that the last stumbling block is getting non-techies to buy into the technology.

Because most of the computer monitors and front and rear projectors except for the very highest-end models can't benefit from the technology, it may be a hard sell.

Also there is a growing shift from CRT based displays to fixed pixel designs like LCD,DLP,D-ILA, plasma.
And although they would benefit from the higher resolution source material to downconvert, we would be relying on advances in scaling technology to have minimal artifacts with such downconversion (which I think is possible).

But already there is flack from companies like Disney who won't support 16:9 enhancement for DVDs because of downconversion artifact concerns on 4:3 TVs, as well as consumers not understanding the 16:9 technology.

And I believe that you would get similar flack from conservative consumers who would already say that 1080i is good enough, or that even 480p is fine.

But as a prospective HD-DVD specification, I would gladly support 20:9 anamorphic, in the same way that I already openly support 16:9 DVDs and 1080p as a ATSC standard.

When these standards were first developed, there was little to no way that they could be used with current technology of the day, and even today for 1080p.

But if you dangle a carrot out there, someone may be enticed to bite.

So, I think it's a great idea, but it will be a hard sell for manufacturers, and moreover content providers, who are only pursuing the mass market consumers.

-Dean.

So, I think it's a great idea, but it will be a hard sell for manufacturers, and moreover content providers, who are only pursuing the mass market consumers.

Agreed that suddenly expecting the market to provide 20x9 capable hardware/software is a tough sell.

But I'm not expecting that.

I'm just saying, "include 20x9 aspect ratio in the HD-DVD standard". Whether content providers (ie Disney) or hardware providers (ie HDTV manufacturers) choose to take advantage of it is optional.

And keep in mind that all fixed-pixel displays rely on scan-conversion regardless of the resolution of the incoming signal [b/]except[/b] in the case that the signal just happens to be the native rate of display...like inputing a 720P signal to a 720P-Plasma display.

Aside from that, everything that goes into that plasma is going to get scan-converted and scaled. 480I. 480P. 1080I. Whatever.

So the fact that fixed-pixel displays might have to scale 20x9 is irrelevant. Why not give scalers the best chance by providing them with the highest resolution to work with? That's the principle behind why all those downconverted 16x9 DVD's from Columbia look as good as they do (the more resolution the scaler has to work with, the better it can minimize aliasing and other artifacts in the downconverted signal).

And just like 16x9 is in the DVD spec regardless of whether Disney decides to use it, and you can watch 16x9 movies regardless of the shape of your TV, why not give the same chance to 20x9? It doesn't cost anything just to write it into the spec. You don't have to "sell" anything to anyone to just provide the option.

Scaling is the future. Improving scaling algorithms are in the future. Big, high-performance projection systems at lower cost are in the future. HD-DVD is in the future. Anamorphic HD-digital projection in theaters is in the future.

Why not 20x9 in the HD-DVD spec.? Nothing to loose.

-dave

Well then Dave we are in agreement.

20:9 SHOULD be included in the HD-DVD spec.



-Dean.

[Colin Dunn]

To add to the vertical sizing discussion...

I believe the ECP-Graphics projector that Dean is using has 4:3 CRTs in it.

However, someone could design (though probably at extreme cost) a projector that uses 16:9 tubes instead of 4:3 tubes. Then add the vertical height and horizontal width adjustments, and it should be possible to go to 20:9 anamorphic squeeze mode.

The key, in my opinion, is to use native 16:9 tubes, like those found in pricey 16:9 HDTV direct-views.

Anyone for a $60,000 widescreen CRT projector? Maybe I need to contemplate a more lucrative career...


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Colin Dunn
DDS-006

Colin,

All FPTVs and RPTVs have 4:3 CRTs.

If 20:9 was attempted, I think that it would be easier to either add anamorphic lenses, so simply design 20:9 LCD panels, which would not be nearly as difficult as making 16:9 CRTs for RPTV/FPTVs.

Or design the current 4:3 CRTS to have more sizing adjustment capability, which should be possible.

-Dean.

>>"Anyone for a $60,000 widescreen CRT projector?"

Hi,

I got my NEC XG135 CRT projector for under $8000 B-stock with new tubes (equivalent of Runco DTV 991/Ultra which is $36,000 US new. Runco are simply "enhanced" NEC's ... but the enhancement, IMHO, is not worth $30,000).

Buying a projector on less than an executive income is possible - though not many people can afford it.

AVSCIENCE at www.avscience.com sells used NEC 6PG Xtra's (the same projector in Blanding's custom built home theater) for $3000 used. They are ~100 pound beasts with 3 lens, in case you don't know much about CRT projectors. But you can use a whopping 100 inch or bigger screen!

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Thanks,
Mark Rejhon
www.marky.com
www.dvdtracker.com/~marky.asp

[This message has been edited by Mark Rejhon (edited 09-05-1999).]