Need to get rid of bars and tone!

[pixellightening]

I am new to the forum, so please bare with me if this has been answered previously. I tried doing a search, but I am sure I am getting some terminology wrong. Anyway...

I am working with a DCP that was created by DCP-o-matic (according to the cpl in the folder).
The film starts with 1:58:02 of bars and tone. The tech at the cinema says he cannot set a new start point within his system.
I am now left with the task of editing the start time of the film. ... Somehow!
Is there a way to edit the start time of a DCP within one or more of the XML documents?
OR
.... within ANY product by DCP-o-matic?

Any help with this would be extremely helpful. Of course the festival is next weekend!
Thank you in advance.
Hank

[Carsten]

After loading that DCP into a new project, simply go to 'Timing', and trim away the unwanted portions - cue to the intended trim position and hit the 'Trim up to current position' or 'Trim after current position'. You can of course also input the trim points as numbers hs:f.

Then click 'Jobs->Make DCP'.

Make sure that before you set the current project to the same parameters as the source DCP (container, wrapping IOP/SMPTE, resolution, number of audio channels, etc.).

The new DCP will be a 1:1 copy of the original, minus the trimmed parts. No quality degradation, as DCP-o-matic will only copy the wanted frames/audio and leave out the trimmed frames. It will also go quickly, but you need the same free disc space as the original DCP occupies.

It is true that cinema projectors have no (easy) means to cut away portions of a DCP. It is not a good idea to edit any file of a DCP by hand.

- Carsten

[pixellightening]

Carsten,

Thank you for the quick reply. Seemed to work. Was not sure about the bandwidth. Although I did some rough calculations using https://toolstud.io/video/dcpsize.php. Figured out that the default 100 Mbit/s was a close enough match.

All that said, as this was my first attempt doing anything in this program, I had a bit of trouble with:
Make sure that before you set the current project to the same parameters as the source DCP (container, wrapping IOP/SMPTE, resolution, number of audio channels, etc.).

Tried to double check everything from the original DCP. Took awhile, but think I got it. Testing in theater tomorrow.

Thanks again for the help!
Hank

[Carsten]

The method I described does not cause recompression, so the bandwidth setting is not relevant - the DCP created will contain exactly the frame data of the original DCP, just that some frames are discarded. You don't need to match data rate of source and target DCP here (these are only very rough figures anyway). You are right, finding and matching just the necessary parameters could turn out a bit difficult at first. Usually the DCP ISDCF name (if assigned properly) and right-click>Properties SHOULD give you the necessary information.

- Carsten

[parksb]

Hello Carsten, is there a way of just setting the Entry Point in the CPL and not really trimming the contents?
Thank you!

[Carsten]

You could do that, but you are on your own there. You would need to recalculate the hash of the CPL to make the new DCP formally correct. It may work on your own system, but if it goes into distribution, editing these files by hand is too much of a risc. What keeps you from doing it by trimming?

- Carsten

[parksb]

Sure, I know that, that's why I wouldn't like to do it manually - did it once and its really a hassle to re-calculate the hashes and re-check everything million times so it works.

For instance, I get all the image and sound deliveries from post with 10 sec countdown and pipser in front. I make a DCP in DoM with trimming it, and then I deliver that DCP and all the other materials (different sound mixes for instance, 5.1, LtRt, whatever) to someone else, and he wants to make some changes, like replacing 5.1 audio with the Stereo one and not reencode the video, just use the existing mxf. It would suddenly have a shorter length than the other "raw" deliveries, which could be confusing, and he wouldn't have in it anymore the pipser that was there as a reference for easily synching. I mean of course it is not a necessity and even in the case I described and other similar cases, everything is possible to work with but it would be a time saving thing. To me it would be a nice feature - and for sure there are other situations in which this feature could help

Thanks, DoM is really great (that's why I would like it to have all possible features haha) - just recently started moving to it from OpenDCP.