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» Film-Tech Forum   » Operations   » Digital Cinema Forum   » Can 4k Play on 2k? (Page 1)

 
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Author Topic: Can 4k Play on 2k?
Jay Glaus
Expert Film Handler

Posts: 117
From: Pittsburgh, PA USA
Registered: Dec 2010


 - posted 07-17-2013 05:35 PM      Profile for Jay Glaus   Author's Homepage   Email Jay Glaus   Send New Private Message       Edit/Delete Post 
I just got a hard drive of Grown Ups 2 and it only has 4k versions on it. I have the 4k version ingested on my GDC. Will the 4k movie play on my 2k setup? I have a Barco 2k 32b.
The last thing we tried to play in 4k was a preview for after earth which was waaaaay too big for the screen. I called deluxe and they said that wouldn't happen, it would be fine. What do you think? [Confused]

UPDATE: they had me go in and change the CineCanvas to Always 2k. Hope that will work.

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Carsten Kurz
Film God

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From: Cologne, NRW, Germany
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 - posted 07-17-2013 06:03 PM      Profile for Carsten Kurz   Email Carsten Kurz   Send New Private Message       Edit/Delete Post 
2k systems will usually play 4k content without you even knowing.

What exact GDC system are you using? IMBs may need to be prepared for always 2k, but that should be done by the installer.

Read this:

http://www.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=16;t=001327#000000

- Carsten

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Justin Hamaker
Film God

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From: Lakeport, CA USA
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 - posted 07-17-2013 08:04 PM      Profile for Justin Hamaker   Author's Homepage   Email Justin Hamaker   Send New Private Message       Edit/Delete Post 
I had the exact same issue with the 32B we just installed at my drive-in. The reason this is an issue is because you have a GDC capable of playing 4K content (probably with an IMB). For this reason you have to tell the server to always output 4K content at 2K. If you have a server that is not capable of playing 4K content, this isn't an issue because it always plays at the 2K resolution (I have 5 GDC servers like this at my 5plex).

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Jay Glaus
Expert Film Handler

Posts: 117
From: Pittsburgh, PA USA
Registered: Dec 2010


 - posted 07-18-2013 11:32 AM      Profile for Jay Glaus   Author's Homepage   Email Jay Glaus   Send New Private Message       Edit/Delete Post 
Thanks guys,
After I set the GDC to Always 2k it worked just fine and put it out at 2k instead of 4k.
Problem solved!

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Jack Ondracek
Film God

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From: Port Orchard, WA, USA
Registered: Oct 2002


 - posted 07-18-2013 12:00 PM      Profile for Jack Ondracek   Author's Homepage   Email Jack Ondracek   Send New Private Message       Edit/Delete Post 
I have yet to see a drive with only 4k versions, so this is interesting.

Are the studios assuming we're all capable of outputting at 2k?

I assume this means longer ingest times & more server space being taken up?

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12206
From: Annapolis, MD
Registered: Dec 1999


 - posted 07-18-2013 01:03 PM      Profile for Steve Guttag   Email Steve Guttag   Send New Private Message       Edit/Delete Post 
Jack, it is a DCI specification that ALL DCI compliant projectors and servers be capable of handling 2K AND 4K files. When the movie is 4K, then the server/projector must extract the 2K core out of the content. I have NEVER seen a DCP where the 2D 4K feature also had a 2K version with it...there would be no point.

Generally speaking, the only time I see issues crop up with 2K/4K is with subtitling/captioning.

If a server outputted a 4K movie as 4K, then the projector should be able to accept that (you may need to change your input/PCF so that it knows that it is a 4K image coming in.

That said, most servers with an (and it is almost an exclusive IMB thing since it involves 4K) have a means to FORCE the 2K version so the projector can just use its standard Flat/Scope files. Again, the only time I've seen that have issues is on subtitles/captions since they are defined in their own file and place the text referenced from the bottom of the screen.

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Justin Hamaker
Film God

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From: Lakeport, CA USA
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 - posted 07-18-2013 01:04 PM      Profile for Justin Hamaker   Author's Homepage   Email Justin Hamaker   Send New Private Message       Edit/Delete Post 
Jack, many, but not all of Sony's features are 4K. This is the End, After Earth and Grown Ups 2 were all 4K, but White House Down was 2K.I've never heard any reason for this, and I don't recall seeing 4K from any other studio (maybe War Horse a few years ago).

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Lance C. McFetridge
Expert Film Handler

Posts: 134
From: Penn Yan, New York
Registered: Jul 99


 - posted 07-18-2013 01:13 PM      Profile for Lance C. McFetridge   Email Lance C. McFetridge   Send New Private Message       Edit/Delete Post 
I was told that Sony released the drives with 4k claiming backwards compatibility. We had to change our GDC servers from "Native" to Always 2K. Deluxe gave us detailed instructions on how to do it. Which is good because my installation tech still hasn't gotten back to me.
Lance

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Antti Nayha
Master Film Handler

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From: Helsinki, Finland
Registered: Oct 2008


 - posted 07-18-2013 03:16 PM      Profile for Antti Nayha   Email Antti Nayha   Send New Private Message       Edit/Delete Post 
For what it's worth, I've seen both 2K and 4K DCP's of "Inception" back in 2010. Those weren't on the same hard drive, though.

More recently, the regular distribution DCP's of "The Dark Knight Rises" and "Skyfall" in our territory (Finland) were both 4K only. I think there are a total of three 4K screens in the whole country, and two of them are operated by our national film archive so they don't play first-run titles...

Also, Michael Haneke's "Love" (Amour) was a 4K DCP - at least the version that toured the international festival circuit last year.

Yes, 4K DCP’s are larger than 2K ones, but thankfully not four times larger even though there are four times more pixels. [Cool]

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Monte L Fullmer
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From: Nampa, Idaho, USA
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 - posted 07-18-2013 03:47 PM      Profile for Monte L Fullmer   Email Monte L Fullmer   Send New Private Message       Edit/Delete Post 
quote:
This is the End, After Earth and Grown Ups 2 were all 4K,
The Latter two, even shown through a 4K Sony unit didn't at all look like a 4K presentation but more like a 2k since the picture quality looks like labwork wasn't up to par as with their 35mm counterparts.

Now, with "The Guardians", along with some others listed as 4K content and being shown through 4K units, did have excellent presentation results.

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Marcel Birgelen
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From: Maastricht, Limburg, Netherlands
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 - posted 07-18-2013 05:44 PM      Profile for Marcel Birgelen   Email Marcel Birgelen   Send New Private Message       Edit/Delete Post 
The Guardians was a fully rendered movie and a big showoff in technology. Targeting a 4K 2D release probably wasn't hard for them, I guess they will even be ready for a 4K 3D re-release.

Unfortunately, many 4K features are shot on RED cameras. Some movies still shot on 35mm are luckily scanned at 4K, like Django Unchained.

After Earth, although a dreadful movie, had a very cinematic look to it. This is the End was shot on those dreadful RED cameras. I did like the movie, but not the dark, video-ish RED picture. And regarding Grown Ups 2: After trying to endure Jack & Jill I've decided to not come close to anything that has Adam Sandler involved in it in any way, so I cannot judge about that.

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Lyle Romer
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From: Davie, FL, USA
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 - posted 07-18-2013 07:50 PM      Profile for Lyle Romer   Email Lyle Romer   Send New Private Message       Edit/Delete Post 
I have to agree with Marcel. The RED cameras (although they are 4k+, I think actually 5k) have a video look to them. The Arri Alexa looks MUCH better even though it is 2.8k or something like that. It looks a lot like film.

It has it's own "look" and doesn't exactly mimic film but it is the closest I've seen from a digital camera. Hopefully Arri will be able to one day produce a 4k version of the Alexa and maintain the other image quality components. Of course, if they keep the super 35 sized sensor increasing the resolution will mean smaller photosites.

The RED cameras look MUCH better than the aweful Panavision Genesis. At least it seems that camera is falling out of favor.

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Scott Jentsch
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From: New Berlin, WI, USA
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 - posted 07-19-2013 10:42 AM      Profile for Scott Jentsch   Author's Homepage   Email Scott Jentsch   Send New Private Message       Edit/Delete Post 
quote: Steve Guttag
When the movie is 4K, then the server/projector must extract the 2K core out of the content.
This statement threw me. A 4K DCP has a 2K core, with the extra resolution filled in as extra information?

I wasn't aware of that, and I can't see how that would work.

Can someone point me in the direction of some reference material on the subject?

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12206
From: Annapolis, MD
Registered: Dec 1999


 - posted 07-19-2013 11:06 AM      Profile for Steve Guttag   Email Steve Guttag   Send New Private Message       Edit/Delete Post 
From the DCI spec (to make sure that the nomenclature is proper). I also only pulled the portions that pertained to a 2K system working with a 4K file.

2.1.1.5.
Hierarchical Image Structure
The DCDM shall use a hierarchical image structure that supports both 2K and 4K resolution files (See Section Section 3.2.1 Image Concepts and Requirements so that studios can choose to deliver either 2K or 4K masters and both 2K and 4K projectors can be deployed and supported. The supported mastering and projecting combinations are illustrated in Figure 3: Hierarchical Image Structure
Media Blocks (MB) for 2K projectors are required to be able to extract and display the 2K-resolution component from the 2K/4K DCP file(s). Media Blocks for 4K projectors are required to be able to output and display the full 4K DCDM. In the case of a 2K DCDM, the output of the Media Block is a 2K image. It is the responsibility of the 4K projectors to up-sample the image.

4.3.
Decoder Specification
4.3.1.
Definitions
•
A 2K distribution – the resolution of the DCDM*7 container is 2048x1080.
•
A 4K distribution – the resolution of the DCDM*7 container is 4096x2160.
•
A 2K decoder outputs up to 2048x1080 resolution data.
•
A 4K decoder outputs up to 4096x2160 resolution data from a 4K compressed file and outputs up to 2048x1080 resolution data from a 2K compressed file.
•
All decoders shall decode both 2K and 4K distributions. It is the responsibility of the 4K projector to upres the 2K file. In the case of a 2K decoder and a 4K distribution, the 2K decoder need read only that data necessary to decode a 2K output from the 4K distribution. The decoder (be it a 2K decoder or a 4K decoder) need not up-sample a 2K image to a 4K projector or down-sample a 4K image to a 2K projector.

•Within 4.3.2:
A 2K decoder shall decode 2K data for every frame in a 4K distribution and it shall decode a 2K distribution. It may discard only the highest resolution level of a 4K distribution. It shall not discard other data such as further resolution levels or quality layers.

From 4.4:
Each compressed frame of a 4K distribution shall have exactly 6 tile parts. Each of the first 3 tile parts shall contain all data necessary to decompress one 2K color component. Each of the next 3 tile parts shall contain all additional data necessary to decompress one 4K color component. The resulting compliant codestream structure is diagramed in Table 7. Assuming D wavelet transform levels (D+1 resolutions), the box labeled 2K_i (i = 0, 1, 2) contains all JPEG 2000 packets for color component i, resolutions 0 through D-1. The box labeled 4K_i (i = 0, 1, 2) contains all JPEG 2000 packets for color component i, resolution D.

A 4K distribution shall have a maximum of 1,302,083 bytes per frame (aggregate of all three color components including headers). Additionally, the 2K portion of each frame shall satisfy the 24 FPS 2K distribution requirements as stated above.

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Carsten Kurz
Film God

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From: Cologne, NRW, Germany
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 - posted 07-19-2013 04:50 PM      Profile for Carsten Kurz   Email Carsten Kurz   Send New Private Message       Edit/Delete Post 
quote: Scott Jentsch
This statement threw me. A 4K DCP has a 2K core, with the extra resolution filled in as extra information?

I wasn't aware of that, and I can't see how that would work.

It's actually part of the wavelet encoding that is the compression part of JPEG2000. It encodes frequency components, that is, you can extract individual frequency components and hence different resolutions without rescaling a full 4k decode on 2k systems. The 2k decoder will just 'skip' over the 4k frequency components.

DCI has been criticized for omitting quite a few things, but at the same time other parts of the spec show quite some far-sightedness.

- Carsten

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