Settings for a 16:9 file with a 2.35 embedded letterbox

[kerri]

Hi,

Some questions from someone who doesn't know what they're doing!

I have a 25fps ProRes video file which is 16:9 with black bars to make a 2.35 letterbox to make into a DCP. Instructions I got from a festival said if your film is letterboxed in the video file, it will misread it as flat, and said to change video to no stretch and scope in the DCP settings, and crop accordingly. However I found that using the scale to width function, I didn't lose any picture as I would have by cropping in the first way.

Should I even be making it scope, as it is letterboxed, but within a 16:9 file?

Thank you for your help!

[carl]

I would suggest setting "scale to" to Scope (and also "container" to Scope in the DCP tab) and then using the crop controls to remove your letterbox. The result should be a Scope DCP which the festival would presumably be happy with.

It might help if you can link to the festival's submission guidelines.

[Carsten]

What Carl says. However, in this case, using 'Scale to fit width' may achieve exactly the same, if you use a scope container and your input file active pixel resolution is very close to the scope aspect ratio (e.g.) 1920*804 for 2.39.

If your file is actually 2.35 ('classic' or 'film' scope, 1920*817 active pixel), you will lose some pixels vertically, but not much (about 6 on top and bottom).

The 'Scale to fit' options are just shortcuts to scaling and cropping parameters to allow a quick full frame alignment. You can insert individual settings and achieve the same, and possibly with a higher accuracy, but you have to know the numbers of your source footage (or do it visually through the preview, which is not pixel accurate).

I assume you are working with DOM 2.10.5, so you should choose the DCI scope container (2.39:1) under the DCP tab.


- Carsten

[cloud06]

It is good idea to select "no stretch" option and manually crop same number of pixels from top and bottom. I sometimes do this when I'm not sure if aspect is 2.35 or 2.39. I would never crop parts of live image... And this option enables you to crop at exact pixels. If you have 2.35 image, this way you can put it in scope container with small pillarbox.

[Dvdscot]

Hello

I have the same, my file is 1280 * 720 (which is 16:9 = 1.78:1) but the film is actually Scope with black bars on top and bottom.

There are two tabs, one for the contents and one for the DCP, what should I select?

Both 2.39 Scope or DCI Flat?
Both 1.78?
Or different, one being Scope and the other being 1.78, just which one?

Thanks.

[Carsten]

Scope under 'DCP', but then under content, select the file and crop vertically and horizontally to the visible picture. You may check 'show content boundaries' under the preview window. I can only guess your scope-letterboxed in 1280/720 is square pixel.

Scope content may be square pixel or anamorphic. Usually, on DVDs, the 16:9 frame is non-square pixel anamorphic, so, techwise, both cropping and stretching is needed to create the square pixel DCP frame. When importing e.g. a Scope DVD, DCP-o-matic is able to recognize the non-square pixels and stretch, but currently it can not detect the letterbox bars automatically.

Bluray with scope content has square pixels, no stretching necessary. It will be handled as a 'normal' 16:9 video, and all you need to do is crop away the letterbox bars.

There are also some rare DVDs with Scope aspect ratio content letterboxed in a 4:3 frame with square pixels. This is the worst incarnation of having scope on DVDs, as the content resolution is only 720/704*306 pixels.

- Carsten

[Dvdscot]

Manually remove the black bars like in a picture program?
I will try this evening and come back to you, thank you!

[Carsten]

Yes, currently, manual cropping top and bottom is the only way to get rid of letterboxing in DCP-o-matic.

- Carsten

[Dvdscot]

Made two conversions, one from a Full HD file into 2.39, that worked in the cinema.
The other one was a 720p file into 2.35, that was not recognized by the server, as if it was not on the HDD. Wrong format? I chose that cause the aspect ratio was different.
Also the server didn't find any of the 9 KDM's that were made by a lab.
How can both be?

[Carsten]

You created encrypted content and let a lab create KDMs for it, or did I get that wrong? Encryption, KDMs and third-party KDM creation is quite complicated to understand (and to explain). Why the second DCP was not recognized, I have no idea, there are many possible reasons for it. What version of DCP-o-matic have you been using?

One possible way to diagnose this is to load the non-functioning DCP into DCP-o-matic, DCP-o-matic player (2.11.x), ideally directly off the transport media ( a bad copy/format could be the reason for this as well).


- Carsten