This is topic Recent DCP File Sizes in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.


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Posted by Noah Katz (Member # 7221) on 10-14-2014, 03:36 PM:
 
Hello Friends. Apparently Technicolor no longer lists file sizes of the DCP Clips in the Projectionist notes. I am trying to keep a list of various DCP package sizes. Does anyone mind posting any Technicolor DCP file sizes here?

Fortunately Deluxe still lists the file sizes. Hopefully Technicolor will follow suite.

Thanks so much!

Noah
 

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Posted by Carsten Kurz (Member # 5396) on 10-14-2014, 06:09 PM:
 
Hi Noah,

this may be somewhat more complicated, but at the same time could be an easier way as you do not have to write it down with every movie: The servers will usually write various logs containing all assets on the machine. It is rather easy to look into these logs every month or so and copy this asset log. Some even list all individual assets of the DCP. Just try to find a way how to do this on your server. When I look into our asset log, I can see all DCPs ever copied to the machine since 9 months or so.

Another option would be a file catalog utility for your preferred OS. Connect each drive for a short time to your PC and let the software browse the directory.

You may need a MoveDock and an EXT2 driver when using Windows or Mac.
I consider a full file list more interesting than just the DCP size. As the files are small, you could even copy all the Metadata files of the DCPs.

Connecting and indexing the distribution drive has the advantage that also file sizes/structures of CPLs are archived that you do not ingest to your server, if you're interested in that sort of thing.

- Carsten
 

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Posted by Noah Katz (Member # 7221) on 10-15-2014, 12:15 PM:
 
Thanks so much for your suggestions!

I am most interested in file sizes for current DCP's because I am trying to keep track of the Estimated BitRates of the various DCP's. For some reason it appears that some of the 4K DCP's I have been seeing seem to have lower bit rates then some of the 2k DCP's. Now of course I should judge a DCP by it's precieved image quality and not by the numeric value of the encoded bit rate, but I cannot help myself Has anyone else here been noticing any trends regarding current DCP's and bit rates? Any thoughts? I know there is a thread from a few years back on the board, but I did not want to resurrect a 2 year old post.
 

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Posted by Carsten Kurz (Member # 5396) on 10-15-2014, 04:58 PM:
 
I guess it is a bit easier to judge bitrates from DCP sizes in the US because most of the time you will probably look at OV versions only. However, with a typical mixed 2D/3D, 5.1/7.1 + language specific version files, this could become more of problem because it is not easy to find out how much space goes with which part of a specific CPL.

As a matter of fact, if you're only interested in video bitrates for compression quality, then reading out just the size and length of the MXF videofile would give a good indication. There can be some variations there as well because the individual image reels may contain content like leaders that are not actually being played, but usually these parts are rather small compared to the visible parts.

I have very often seen stickers on drives that do not really give a proper indication for the size of specific CPLs. Therefore I guess a full directory or even metadata catalog would be quite handy in the long term, since you can extract a lot of very useful data from PKL, CPL, etc. Plus these files are very small and compress very well.

- Carsten
 

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Posted by Bobby Henderson (Member # 840) on 10-16-2014, 11:07 AM:
 
Obviously people at different movie studios have different philosophies regarding compression levels. Some want as little compression as possible while others want as much as possible. One 2 hour DCP may weigh in at over 200GB while another 2 hour movie from a different studio may weigh just 55GB.

JPEG2000 has some improvements over the standard JPEG format, but if one follows the quality guidelines that appear to only be followed in the past one would end up with very big DCP files after the encoding job was finished. I just don't see how one can squeeze a 2K movie down to something in the neighborhood of 50GB with no more than 3 transform blocks allowed per frame.

I really don't understand why there is still a 250 million bit per second limit on bit rate, even if the content is 4K.

If these studio honchos keep squeezing compression levels worse and worse, particularly with 4K content they might as well dump JPEG2000 and go with a real video compression codec that can do things like inter-frame compression. At a 50GB file size one could probably get better results using MPEG-4 AVC or MPEG HEVC than JPEG2000.
 

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Posted by Carsten Kurz (Member # 5396) on 10-16-2014, 11:11 AM:
 
The only DCPs being so small that I have seen were either animation-type or cheap BluRay conversions.

Also, various J2K algorithms deal very different with the space budget. I heard that OpenJPEG as a reference implementation wastes a good amount of data and as such will always deliver larger files, while other implementations get to the same quality with less file sizes.

Yet to prove that.

- Carsten
 

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Posted by Bobby Henderson (Member # 840) on 10-16-2014, 01:40 PM:
 
I've seen several Warner Bros. features with DCP file sizes relatively small compared to those from other studios. I remember one of the Harry Potter movies having a DCP sized only in the 60GB neighborhood while other DCPs from studios like Paramount were going well over 200GB.

WB has a history of doing the same thing in consumer media, with DVD and Blu-ray encode file sizes being well below average. A typical WB Blu-ray only needs to be on a dual layer 50GB disc just to hold extra content. It's like they do just enough to get it past that 25GB threshold, as if they're still encoding for HD-DVD but adding lossless audio instead. Customers see the dual layer specification and think the video encode is just as good as the high bit rate encodes coming from other studios, like Paramount or Sony.
 

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Posted by Noah Katz (Member # 7221) on 10-16-2014, 03:21 PM:
 
I read something interesting regarding the fact that in Jpeg2000 the

quote:

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".....Generally, higher quality and/or higher resolution imagery require fewer bits per pixel than lower quality
(noisy) and/or lower resolution imagery"

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