4K Blu-ray content on the horizon?

[Anthony P]

Originally Posted by kristoffer

How much room does a 4K movie at same compression as the best BDs today need?
200 GB?

tough question. If movies where not compressed in any form the answer would be 4x the BD but in order to answer your question one would need to define what does "same compression" means.

But no matter how it is defined it would be much less then 4x what the BD uses for 2k. In order to understand why one needs to understand how video compression work. p and b frames only save the changes from the previous /next frame so if two frames are identical, there should not be any difference in information in the p/b frame no matter what the resolution it is it would only have the header info and no pixel/block info. Even if the frame is not 100% the same a large chunk of it will most likely be (or else the encoder would have used an i frame). Also even if one looks at a single frame, because each pixel is smaller, there can be better blocking opportunities that don't destroy any more information (actually could destroy less) so it could save there as well (i.e. let's assume at 2k we have a checker board where each square is 4 pixels, since MPEG2/AVC only have 8pixel blocks that would need to be encoded as pixels or it would really destroy the image, but if you move to 4k each of the checker board squares is 8 pixels and so the perfect size to block without ruining the picture.

[singhcr]

Originally Posted by Anthony P

tough question. If movies where not compressed in any form the answer would be 4x the BD but in order to answer your question one would need to define what does "same compression" means.

But no matter how it is defined it would be much less then 4x what the BD uses for 2k. In order to understand why one needs to understand how video compression work. p and b frames only save the changes from the previous /next frame so if two frames are identical, there should not be any difference in information in the p/b frame no matter what the resolution it is it would only have the header info and no pixel/block info. Even if the frame is not 100% the same a large chunk of it will most likely be (or else the encoder would have used an i frame). Also even if one looks at a single frame, because each pixel is smaller, there can be better blocking opportunities that don't destroy any more information (actually could destroy less) so it could save there as well (i.e. let's assume at 2k we have a checker board where each square is 4 pixels, since MPEG2/AVC only have 8pixel blocks that would need to be encoded as pixels or it would really destroy the image, but if you move to 4k each of the checker board squares is 8 pixels and so the perfect size to block without ruining the picture.

I've always wondered how video compression works, but I never figured out how. I get bits and pieces of this, but I don't know what p and b frames are, for example. Could you explain these concepts to me? Thanks!

[Anthony P]

Originally Posted by singhcr

I've always wondered how video compression works, but I never figured out how. I get bits and pieces of this, but I don't know what p and b frames are, for example. Could you explain these concepts to me? Thanks!

It is not hard, but I hop you will allow me to go a bit beyond just those two.

Every CODEC works with a GOP: GOP is short for Group Of Pictures and the name tells it all , it is several frames that belong together. Now the GOP can be partially defined by the CODEC, it can be partially defined by the Format (rules for GOP were different for BD and HD-DVD) and partially by the content.
Now the GOP will have three types of pictures, i-frames, p-frames and b-frames.

i: is an intra-coded frame and one is found at either end of the GOP and defines the GOP. I prefer to think of it as Independent, since it has all the pixel information for the picture it represents, if you had nothing else, you could still rebuild that whole frame.

a codec/format would have places where they require an i-frame, these are needed in order to be able to play back properly, for example, to FF or rew. An encoder could also decide to use an i-frame because the picture itself is too different, for example if there was a scene change

p: is a predicted frame, it is a frame that is based on a Previous frame, and all it has is the information that changed from that previous reference frame. So if, like I said before, the previous one and this p-frame are exactly the same, then it does not need to have any picture info, but it would still have the header information, so it will take more than 0 bits.If that was not there, how would the decoder know that that there is supposed to be a p-frame that is exactly as the previous frame? Now on the other hand if some pixels are completely different, it could have that info and if something has moved (like in a bad cartoon where movement is done by moving a still a bit to one side) it will have what group of pixels moved where.

b: is a Bi-predictive frame: and it works a lot like a p-frame but it is not only from one direction but can be Both , how is it different from the previous and how is it different from the next one.

That is why I find it helps to think of i as Independent, P as previous and B as both to help me remember which is which.

[Anthony P]

PS googled images ipb frames and found this


so in this GOP the first i-frame has packman and some dots, the p-frame that follows has "move the block of dots a bit to the left" that is why in the p (and b) image packman is light because he has not changed so not actually encoded in the frame (he remains the same), the b frame has "move those three dots a bit more to the left" as well as "add that block with the dot from the next i-frame" and the next I-frame has packman with the 4 dots.

[pro-bassoonist]

Originally Posted by singhcr

Star Wars was shot on 35mm film. It will get no more detailed than 4k. Once you buy that, you've essentially bought the original negative. This makes me wonder if studios will ever release a home copy of a movie where you'd never need to upgrade again.

https://forum.blu-ray.com/5258644-post13.html

Originally Posted by pro-bassoonist

It won't look horrible but there will be obvious limitations.

This said, I believe that at some point in the future we will see 4K content on the market. However, I remain a firm believer that 4K content will be extremely limited as the content owners will not be willing to essentially offer their masters for pennies. More than likely there will be different protection enhancements as well.

Two years ago we saw prototypes (4K monitors) at CES in Las Vegas. If I recall correctly they were 65'+. The biggest improvement, in my opinion, was in color reproduction. In other words, I think that the majority of the people with very large screens (lets say 120'+) will be most impressed with the wider range - and in particular depth - of colors.

I can see myself experimenting with a 4K projector, but I remain a skeptic as far as 4K content is concerned, as I do not believe that 4K will become a standard for mass catalog releases. The more likely scenario is that the codecs we have now for Blu-ray will continue to mature and we will see even better results (which is what Blueshadow has noted above as well).

Pro-B

[singhcr]

That is a good point, pro-b. However, considering most movies these days are 2k and BD is ~1.9k, don't we basically get a master copy of those movies? I realize the BD is more compressed than the 2k DI is, but they're pretty close. In the case of Star Wars Episode II and III the BD is the master, although those are exceptions to the rule.

AnthonyP: thanks for the explaniation! That makes much more sense now.

[ZoetMB]

Originally Posted by Trogdor2010

however the larger 70mm (as well as IMAX) were really for experimental use only to drive larger theater venues (still is awesome though).

Limited distribution and primarily in large cities, yes. Experimental use, no (except in the large format experiments of the 1930s). And while 70mm generally played in theatres that are larger than today's theatres, they weren't necessarily larger than other theatres of their time that only played 35mm. In cities, single-screen 2000 seat theatres in local neighborhoods was the norm, not the exception. Now we have 10-screen multiplexes with a total of 2000 seats.

The primary purpose of 70mm was not as much to show a larger image or better image quality (even though the improved resolution and the ability to get more light behind the frame when projecting did improve PQ). It was to get the benefit of the 6-track magnetic soundtrack. That's why when Panavision developed the 35mm to 70mm blowup process, almost all 65mm origination disappeared. There was Baraka, Hamlet and Ron Howard's attempt to revive the format for "Far and Away", but that was it. And when 5.1 digital sound came along, that put the final nail in the 70mm coffin, even for blowups.

[Trogdor2010]

Originally Posted by singhcr

Is 16mm in that much use compared to 35mm in the history of film? In any event it was just an estimate.

Sorry that I was a bit rude there.

However, documentary filmmaking especially is such a large contribution to the current legacy of filmmaking that to not consider it be a bash on what has been done. Many documentaries were shot with smaller 16mm or 8mm, now with Hollywood that is a deathwish, since the use of filmmaking cameras are to specialize a type of filmmaking, and in general, 35mm is significantly more expensive than 16mm.

Originally Posted by ZoetMB

Limited distribution and primarily in large cities, yes. Experimental use, no (except in the large format experiments of the 1930s). And while 70mm generally played in theatres that are larger than today's theatres, they weren't necessarily larger than other theatres of their time that only played 35mm. In cities, single-screen 2000 seat theatres in local neighborhoods was the norm, not the exception. Now we have 10-screen multiplexes with a total of 2000 seats.

The primary purpose of 70mm was not as much to show a larger image or better image quality (even though the improved resolution and the ability to get more light behind the frame when projecting did improve PQ). It was to get the benefit of the 6-track magnetic soundtrack. That's why when Panavision developed the 35mm to 70mm blowup process, almost all 65mm origination disappeared. There was Baraka, Hamlet and Ron Howard's attempt to revive the format for "Far and Away", but that was it. And when 5.1 digital sound came along, that put the final nail in the 70mm coffin, even for blowups.

It might reflect more on the post-Blockbuster Era of movies that churn out a massive market of movies; you can't simply drive large theater venues without taking a (technical) risk. I think the much, much larger distribution of movies by these studios is where theater chains are breaking now. It doesn't help now that you can have thousands of movies to pick just by looking up a torrent site.

I think we are heading for a more impersonal embrace of movies, since alot of people could just use a laptop, without being able to see people participating in the movies that we are watching. That I think is why 70mm stopped being adopted in the end, not because there was something better.

[pro-bassoonist]

Originally Posted by singhcr

That is a good point, pro-b. However, considering most movies these days are 2k and BD is ~1.9k, don't we basically get a master copy of those movies? I realize the BD is more compressed than the 2k DI is, but they're pretty close. In the case of Star Wars Episode II and III the BD is the master, although those are exceptions to the rule.

That is my view - precisely for the reasons you mentioned above. The issue of course is what type of 2K master is there to work with. What I mean is, a 2K master and transfer struck from that master in 2011 could look very different from a master (and a transfer) done in 2008.

As I said before, I don't see how 4K will inspire any sort of a mass format, because you are talking about a massive restructuring of the production cycle. In this economic climate, I believe it is naive to expect that the studios would consider anything like it because the returns will be miserable. They will have to invest massive amounts of money for...pennies. (Outside of the U.S., this is certainly science fiction territory). So, they would be content to push MOD programs for cheap DVDs, or UV copycats, which is why I constantly keep reminding people how important it is to support Blu-ray.

I don't want to sound like a broken record here, but if you are a film enthusiast and seriously care about quality, Blu-ray is your only option to own great content, with the proper quality, in your library.

If anything is to change in the future, and I don't mean the near future, Sony will again have a lot to do with it - as they are really the only party to seriously invest into 4K content, and more importantly have the tech and financial support to cause serious developments on the market. My guess is, however, that they would work on better codecs and work with Blu-ray's portfolio rather than consider alternatives (like the much hyped Red Ray).

Pro-B

[mredman]

The blu rays i have now looks amazing right now. And if they come out in 4K i will not buy them again. But if new movies come out in 4K then of course i will start there. But i will double dip some of the titles if they release them in 4K resolution. Because the versions that are out now does look pretty damn fantastic.

[in2video2]

Originally Posted by pro-bassoonist

I don't want to sound like a broken record here, but if you are a film enthusiast and seriously care about quality, Blu-ray is your only option to own great content, with the proper quality, in your library.

Pro-B

This view has been my conviction as well. Blu-Ray will quite likely become our last great chance to preserve our film heritage. Aside from future investment in HD Streaming which for most serves its own purpose, those focused on collecting extensive Film Library content for future generations will at least possess a hands-on access for all time.

[Anthony P]

Originally Posted by pro-bassoonist

I don't want to sound like a broken record here, but if you are a film enthusiast and seriously care about quality, Blu-ray is your only option to own great content, with the proper quality, in your library.

agree, though I would say
if you are a film enthusiast and seriously care about quality, Blu-ray is your only option to watch a movie at home.

I realy don’t get the “it is a rental so I don’t care”. The eyes are the same the person is the same, if you don’t care because it is a rental then you don’t care.

[Scholer]

Originally Posted by singhcr

As I said earlier, practically all movies made from the mid 2000s to today were finalized at 2k by scanning the 35mm negatives, and BD is essentially 2k.

4k is the resolution that is equivalent to an original 35mm negative. 35mm has been used for basically every movie made to date. Any movie that didn't use a 2k digital intermediate would max out at 4k resolution.

16mm movies, however rare, top out at roughly 1080p resolution.

70mm/65mm/IMAX movies are roughly equivalent to 8k. There are only a handful of these movies made.

So in the history of movies, you get this very rough breakdown:

35mm [4k]: (1898-2005), ~95% of all movies made
Digital Intermediate (DI) [2k scan of 35mm negative] (2005-present) ~4% of all movies made
70mm [8k] (1960s-1980s) <1% of all movies made
IMAX [8k] (1990)<1%
16mm [1080p] <1%

As I said earlier, with the exception of 70mm/IMAX and new content, 4k covers essentially all movies made to date. TV shows also top out at 4k if they were shot on 35mm film, like Star Trek: TNG.

Star Wars was shot on 35mm film. It will get no more detailed than 4k. Once you buy that, you've essentially bought the original negative. This makes me wonder if studios will ever release a home copy of a movie where you'd never need to upgrade again.

But Star Wars was shot in Panavision, therefore in an extent 2 times 35mm, so 4k would be proper for Super 35mm, 35mm, Techniscope Movies. Movies shot in Panavision looks best in a 6K Scan.

[PRO-630HD]

Originally Posted by Scholer

But Star Wars was shot in Panavision, therefore in an extent 2 times 35mm, so 4k would be proper for Super 35mm, 35mm, Techniscope Movies. Movies shot in Panavision looks best in a 6K Scan.

In a word no, you are thinking of Vistavision that has a much larger negative than 35mm film and is sideways. Panavision or anamorphic 35mm has a 4K resolution of around 1714 x 4096.

[MisterXDTV]

Originally Posted by scorpiontail60

4k is four times the resolution of 1080p so it will require four times the bitrate to look acceptable. The majority of Blu-rays seem to be settling for 20-30 Mbps AVC which looks pretty good.

Absolutely not, 4k is about two times the resolution of 1080p, the K refers to horizontal resolution while 1080p refers to the vertical resolution...

Full HD= 1920p
2K= 2048p
4K= 4096p

[lobosrul]

Originally Posted by MisterXDTV

Absolutely not, 4k is about two times the resolution of 1080p, the K refers to horizontal resolution while 1080p refers to the vertical resolution...

Full HD= 1920p
2K= 2048p
4K= 4096p

Yes, and no. 4k is 4096x2304 (assuming 16x9) so it is 9.4 megapixels, or just over 4 times as many pixels per frame than that of "Full HD".

4000 line video, ie Ultra HD, will require approximately 16 times greater video bitrate over 1080p. Assuming video compression techniques aren't improved that is.

[lobosrul]

Originally Posted by Scholer

But Star Wars was shot in Panavision, therefore in an extent 2 times 35mm, so 4k would be proper for Super 35mm, 35mm, Techniscope Movies. Movies shot in Panavision looks best in a 6K Scan.

Originally Posted by PRO-630HD

In a word no, you are thinking of Vistavision that has a much larger negative than 35mm film and is sideways. Panavision or anamorphic 35mm has a 4K resolution of around 1714 x 4096.

The contact area of an anamorphic 35mm film is actually quite a bit greater than one masked for a 1.85:1 AR. However, a film shot at the "academy" ratio would be pretty much the same as one shot anamorphically on 35mm. I'm unconvinced that 35mm film scanned in at 6k would look any better than 2000 lines.

See: http://widescreenmuseum.com/widescreen/aspectratio.htm

[Neomic]

I don't see 4K coming to the home market for another 10 to 20 years. Also not until the 1TB BD that is being developed is mass produced, which may be a long time from now. Even then, I would think they would probably just use those to put TV seasons on 1 disc to reduce manufacturing costs and raise efficiency.

[Steedeel]

4k will be here sooner than that.

[Beaner666]

First off let me state that I am no expert so please forgive me if any of this info is wrong or incorrect, but is 4K resolution even necessary?

The reason I am asking is that a growing number of directors have been filming their movies using digital cinematography and use the Panavision Genesis camera which is only 1920x1080 anyway.

If 1080p is good enough for a professional film director why do we need 4K for home use?