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Discussion Starter · #1 ·
Many past threads have discussed the issue of using the full 480 lines of resolution for 2.35 aspect ratio movies in the current DVD Video format.


Currently, as we all know, any movie with an aspect ratio greater than 1.78 has black bars in the 1.78 anamorphic frame (or black bars in the 4:3 frame for non-anamorphic DVDs), wasting valuable vertical resolution.


If a Criterion (from the Criterion Laserdisk days of yore) or similar publisher were to produce videophile-grade DVD remasters of select movies in a "super anamorphic" format that uses 100% of the DVD's 480-viewable-line vertical resolution, how much would you be willing to pay?


What movies would you like to see re-released in a super-anamorphic format?


Of course, this type of DVD would require a HTPC or scaler and/or anamorphic lens to view in full resolution.


Other technical improvements that could be included in Criterion/Moble Fidelity-class DVDs:


.New 24/96 5.1 channel DTS soundtracks (hi res sound to go with a hi-res picture http://www.avsforum.com/ubb/wink.gif ).

.*Real* digital re-mastering: color correction, no edge enhancement, less MPEG compression, clean up of film dirt/scratches, etc.

.Other?


Yes, we could wait for HD-DVD to give us more resolution, but if HD-DVD is standardized at 1280x720p, 2.35 movies would still have only 1280/2.35= 545 vertical lines.


The current DVD format could deliver videophiles 480 vertical lines today for 2.35/2.2/etc movies, which is pretty close to 545 lines (88% is close enough for me http://www.avsforum.com/ubb/wink.gif )!


 

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The MPEG 2 scheme is designed to accomodate 3 aspect ratios:


4x3, 16x9, and 20x9.


DVD uses the first two. But the third (which I think works out to about 2.2:1) would be perfect for 2.35:1 films.


Why this odd-ball aspect ratio?


Because you can't have an infinitely variable aspect ratio as you'd have to have VERY expensive scalers built-into DVD player to downconvert for other aspect-ratio displays. Just like downconverting from 16x9 to 4x3 lbx is pretty simple math (the DVD player taking every 4 lines and folding down into 3) the same simple integer math applies to downconverting form 20x9 to 16x9 or 4x3. I think it works out that to go from 20x9 to 16x9 takes every 5 lines down to 4, and to go from 20x9 to 4x3 takes every 5 lines down to 3.


So you have a 16x9 TV? No problem...set your dvd player to 16x9 and it will downconvert 20x9 discs the same way dvd players downconvert 16x9 for 4x3 sets now.


Of course, anyone with a projector or display capable of using all that resolution could leave the image in native form.

The feature is already there in the MPEG standard. It's just a matter of making use of it.


I for one have written about this a number of times on various forums. I'd like to see the HD-DVD standard make use of it. Why not get all you can? Those HD films projected in movie-houses are using all the available vertical resolution in the 1080 frame. Why can't we (come close to it) do the same with 20x9 1080P HD encoding?

Also:


When having technical discussions about aspect ratio encoding, it's best not to refer to it as "anamorphic". That's just a venacular use of a word that really doesn't apply to the digital medium. There's nothing "anamorphic" about a 16x9 DVD. It's just a DVD encoded for a 16x9 frame instead of a 4x3 frame. The semantic use of the word "anamorphic" is just a point of view. If 16x9 were the standard, then we'd all be calling 4x3 DVDs "anamorphic" because they looked fat when we set our displays to "full" mode. I try to stick to the phrase "16x9 encoded" vs "4x3 encoded".


We really need to push big-time for the maxiumum quality HD-DVD can provide. First off, that means nothing less than 1080P HD resolution. Forget 720P. It makes me nervous that people still talk about that. Joe Kane is big into this 720P thing only because he thinks it would be cool if we used the current DVD platform/laser to hold 720P movies...which could almost fit a 2 hour program if nothing else were on the disc (given 2 sides/2 layers). This would necessitate a side-change which, IMO, isn't indicative of a legitmate carrier technology.


The Technology for real 1080P DVD with mulitple languages of uncompressed 7 channel DSD or 192/24 resolution PCM sound is already there. It's called FMD. What's standing between you and me and watching Braveheart in 1080P with no compression artifacts and perfect master-quality sound is not technology. It's politics.


-dave


[This message has been edited by DaViD Boulet (edited 08-21-2001).]
 

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Dave,

your opinion about the use of the term "anamorphic" is one I have been expressing for 3 years. It was nice to see it from somebody else, I tired of hearing myself drone on about it.


Because of basic economics, I believe these disk would be exceedingly expensive. Unless there is a viable 2.35:1 monitor that sells in volume, I doubt we will see this at sell through for less than 100 dollars in the next 5 years.


Dave that is a boat load of data your looking to get on that disk. FMD sounds great, but 720p is nice as an interim solution.


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Don O
 

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Don,


I guess I haven't paid as much attention to the terminology of DVD MPEG encoding as I would need to understand this "anamorphic" discussion. And I hate to open up a can of worms, but ...


If "anamorphic" meant the image was recorded using non-square pixels, then I'd buy that definition. But 720 x 480 is an odd number to me.


On the thread topic, yes, I would pay double normal street prices -- say $35-$45 -- for DVDs of scope movies using the full 720 x 480 pixels available in the 16:9 DVD standard. There are not many movies I would do it for, however. Maybe a dozen.


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*********************

Kirk Ellis

G1000 D-ILA, HTPC, Panamorph (soon I hope),

Dish 6000 (HBOHD,SHOHD,CBS,NBC,ABC,WB,FOX,UPN, KCET -- does it get any better ?)
 

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Dave-


Excellent post. I agree entirely, but just wanted to point out a couple of nits:

Quote:
Those HD films projected in movie-houses are using all the available vertical resolution in the 1080 frame.
Actually, current digital cinema technology uses 1280x1024 content, stretched optically with the appropriate anamorphic expansion lens to get the desired aspect ratio. Not quite 1080p, but who's counting http://www.avsforum.com/ubb/wink.gif .

Quote:
This would necessitate a side-change which, IMO, isn't indicative of a legitmate carrier technology.
If I understand it correctly, FMD would necessitate many layer changes, not just two. I see the layer changes as a non-issue, provided large enough digital buffers are put in the hardware to alleviate the annoying blip in the video. It shouldn't be that hard. Really no different than the anti-skip CD logic, except with much larger buffers of course!


Don-

Quote:
Unless there is a viable 2.35:1 monitor that sells in volume, I doubt we will see this at sell through for less than 100 dollars in the next 5 years.
I don't think a 2.35:1 monitor will ever be made, but the convergence of computers and consumer video makes this a non-issue. 16:9 DVDs are awesome on a HTPC because the software DVD player knows to scale the video image to the correct aspect ratio, and the computer's video card has scalers superior to most set-top DVD players. Perhaps if the convergence of computers and video goes mainstream, (instead of just among us kooks http://www.avsforum.com/ubb/wink.gif ), the format might have viability. I'm with David Boulet though, DVD is already old hat. Bring on 1080p!


Dave W



[This message has been edited by Dave W (edited 08-21-2001).]
 

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Kirk,

when in doubt go to the source. DVD demystified-IMO-a must reference book, with disk for the HT geek at heart.


Your assumptions are all correct. The ratio of the number of horizontal (720) to vertical (480) pixels does not equate to any AR format. DVD is not a square pixel technology like HDTV. To optimize for different displays they can manipulate the H/W relationship of all the pixels in the array to optimize for different monitors. No lenses are used. Simply put the 16:9 enhanced disks use wider, shorter pixels.


The explanation is here


Dave W,

we will have to convince the MPAA not to downconvert 1080i. Getting them to sell us a 20 dollar dvd with 1080p resolution is a pipe dream. Dream on, I am with you.


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Don O


[This message has been edited by Don O'Brien (edited 08-21-2001).]
 

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If a new type of DVD with 720:480 resolution with full 4:4:4 chroma resolution goes on sale I'll buy it but just a 33 percent increase in vertical resolution won't get it.


FMD might never make it to market. Have you checked their stock lately? Here it is. Not looking too good.


Frank
 

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Don-


For film based material, 1080i is equivalent to 1080p, as long as you undo the inverse 3:2 pulldown, which is trivial in the digital domain. This is what HTPCs and progressive DVD players are currently doing with DVDs, which are encoded in 480i.


Dave W
 

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Ahh, it's nice to read threads where every post is so intelligent and striving for accuracy. This is why I switched from newsgroups http://www.avsforum.com/ubb/smile.gif

Quote:
If "anamorphic" meant the image was recorded using non-square pixels, then I'd buy that definition.
As one previous poster mentioned, the pixels aren't square in 4x3 aspect ratio either! In 4x3 aspect ratio the 720x480 pixel array has taller pixels than they are wide, and in 16x9 has wider pixels than they are tall.


Bottom line is who cares what shape the pixels are...more res = better image.


I also agree that even if someone like Joe Kane insists that 720P DVD is somehow the holy-grail, we'll all be watching REAL 1080P DVDs when HD-DVD players come out that do the deinterlacing in the digital domain just like we watch REAL 480P today.


The only catch is if we can keep the studios from vertical filtering the image to reduce aliasing for interlaced playback. I say let the DVD player do the filtering and preserve as much native resolution as you can on the disc itself.


-dave
 

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Quote:
The only catch is if we can keep the studios from vertical filtering the image to reduce aliasing for interlaced playback. I say let the DVD player do the filtering and preserve as much native resolution as you can on the disc itself.
Man, do I hear that! Unfortunately, that would go contrary to the industry's obsession with doing everything at the source end, an artifact from the days of vacuum tube televisions, where you couldn't really do any signal processing at the destination. But since TVs went solid state, that's no longer true. How about edge enhancement? Every TV made for the last 15 years has that good ole "sharpness" control, which essentially is an edge enhancement circuit. Yet do the studios leave it up to the user to turn up the sharpness if they find that sort of thing desirable? No, they put it right in the DVD data, so everyone gets to "enjoy" it. Now that digital TV is a reality, source-end signal processing should be discouraged.


Dave
 

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Discussion Starter · #11 ·
My psychic powers must be working- http://www.avsforum.com/ubb/Forum12/HTML/013516.html


describes a new high-end videophile-oriented line of re-mastered (current technology) DVD's from Sony. Using higher bit rates (less MPEG compression) and eliminating extras to maximize disk space for video data, these Superbit DVD's will attempt to be what this thread was started for...


Except it's not clear if they will use all 480 vertical lines for 2.35 movies...


This could open the floodgates for other publishers to cater to videophiles looking for the best resolution image (spatial, temporal, and color).


This is our Big Chance to air our grievances against edge enhancement, excessive compression, and reduced color and vertical resolutions.



[This message has been edited by Rgb (edited 08-22-2001).]
 

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I think it is important to reserve judgement on these superbit DVDs until they present. It has been quoted by many to run the data rate above 6Mb/s is unneccessary unless the image is extremely complex with alot of movement. This may be misinformation, but I have seen three sources (WSR, TPV, and one reliable source on the net that has stated such) The maximum rate for DVD is just over 10Mb/s, but to run it at a rate close to that continuously will provide no benefit in static scenes. There is no evidence they are going to do this by the way. Most of us would settle for elimination of edge enhancement and filtering.


Today's 480p60 is still derived from 24 interlaced field pairs. At 60p with inverse telecine engaged you still have judder because the sequence is still 3:2 or 2:3 progressive. To individual who watch mostly pal programming, this judder is very apparent. Unless you kick the frame rate up to 71.928hz and use 3:3 reverse pulldown with good film detection capability, you will still have judder.


1080i, I do not believe we have seen the best of this yet. Many source have reported that much of the programming is horizontally filtered, to drop the data rate from 19.3Mb/s to just below 13Mb/s. Despite the pixel format being identical (1920*1080), the resultant horizontal resolution is equivalent to 1280 lines.


I frankly have no personal experience with 1080i to 1080p conversion, but it currently is not financially trivial. With only a few models like the F5000 offering this type of function. But still, interlacing frequenly involves filtering (as mentioned previously) to avoid aliasing and still is converting a 24fps to 60fps, which theoretically will leave us with judder because of unequal temporal exposure of the interlaced field pairs. Get monitors that can scan high, because 1080p72 (71.928) should be the way to go. I believe 67.5K will be necessary.


Cheers Gents



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Don O


[This message has been edited by Don O'Brien (edited 08-22-2001).]
 

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I'm also curious but doubtful about how much picture improvement that we will see with the upcoming Superbit DVDs.


Columbia/Tristar has almost always used 1080p HD masters to create their DVDs, and generally considers 16:9 enhancement to be a standard for optimal DVD quality. So their DVDs are already top-notch efforts.


Despite some filtering and transfer issues, the C/T DVDs are among the best looking DVDs out there, and it will be tough to improve them.


As far a 20:9 DVDs goes, I've always liked the idea, but there aren't many CRT displays (monitors, RPTVs and FPTVs) that have the range to adjust the picture's vertical height to roughly 50% of the normal size to support 20:9 mastered DVDs.


And even though it's in the MPEG2 specs (which is good) I've been to a DVD mastering facility, and even though the DVD creation software had a formatting button for 16:9 mastering, there was nothing about 20:9 or variable formatting capability, so the mastering software would most likely have to be customized to support that format.


With all of that said, I'd love to see 1080p mastered 20:9 DVDs, and I'd happily pay twice what a standard DVD costs to get them made. But I'm biased because I have a HTPC and Panamorph II lens on order, which would make 20:9 DVD playback possible if PowerDVD or WinDVD supported the playback decompression mode. I'd love it.


Of course, I'd love 1080i/p or 720p DVDs today, but I don't see it happening with all that the MPAA is doing with their lower resolution home video efforts.


-Dean.
 

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Quote:
Many source have reported that much of the programming is horizontally filtered, to drop the data rate from 19.3Mb/s to just below 13Mb/s. Despite the pixel format being identical (1920*1080), the resultant horizontal resolution is equivalent to 1280 lines.
This supports my theory that the 1080i broadcasts we're seeing aren't really that much better than 540p, especially on RPTVs with 7" CRTs. However, the chroma bandwidth of 1080i is way higher than 540p.


Dave
 

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We should all keep in mind that with HD-DVD film-transfers, which don't incur the same limitations of live-HD video capture, there's not a technological need or advantage to filter at the analog->digital conversion. I belive when Sony prepares a 1080P master from a film source that this represents as pristine and unprocessed an image as they can get (other than the bare minmum to eliminate aliasing from pixel-sampling).


What happens from there depends on the final source. Obviously some filtering would need to take place if the image were to be down-sampled to 720x480. But a 1080 image on an HD-DVD...whether encoded for progressive or interlaced...does not require any additional filtering. I believe that Titanic is an example of a DVD transfer that did not employ any vertical filtering which is usually applied to reduce line-aliasing on 480I displays. For this reason aliasing is pretty apparent, but the image is very sharp and full of detail without edge-enhancment. Funny how they'd go to that extreme and then code the progressive-flags incorrectly and not use a 16x9 aspect ratio!


Anyway...hopefully as HD-DVD will be aimed at a videophile market and one replete with advancing technology, filtering will be something left for the player to perform if it needs to output an interlaced image--analagous to the way today's dvd players render filtered 4x3 images from 16x9 encoded discs. That way the source signal isn't compromised even if the play-back hardware or display happens to be.


Throw 20x9 encoding into the mix and we've got one hell of a picture!!!


Maybe by then we'll have enough bandwidth that something better than MPEG2 will be utilized. I know that digital cinema uses a superior, albiet more bit-hungry codec.


-dave



[This message has been edited by DaViD Boulet (edited 08-23-2001).]
 

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If we wish to go back to the transfer and development of the HD master, we must inlcude the fact they use a contrast reduced IP of the film to create this transfer. Joe Kane demonstrated quite long ago that use of the IN was superior.


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Don O
 
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