Picture start & picture end markers

[stefan]

Hello there
I'm a first time caller and beginner dcp'r
Our client is requesting a single DCP containing reels. Each reel needing an entry point with reel duration being coded into the CPL. Is this possible within DCPoMatic ?
They require the film leader on the beginning and end of each reel so we can't simply trim the reel.

Kind regards

[Carsten]

Unless Carl comes up with a special workaround, as far as I know, this is not possible currently. DCP-o-matic does not offer a reel based assembly method. While DCP-o-matic supports segmenting into reels, and conveying reel structures from existing DCPs, there currently is no way to transport source based reels with non-zero offset points into the CPL. One could hack the CPL manually to create these in/out points, but that is only the very last resort when under pressure to deliver a DCP in time.

- Carsten

[carl]

As Carsten says I can't think of a way to do this with DCP-o-matic as it stands. It's something we could add, perhaps with some control somewhere to trim using the CPL rather than by actually trimming the assets. I guess this could also be useful if people wanted to make VFs which trim parts of OV DCPs.

What's your timescale on this? How quickly would the feature need to be added to solve your problem in time?

[stefan]

Hi Carl and Carsten.
Thanks so much for you replies.
Typically the timeframe is short I believe we need to deliver at the end of this week.
Carsten , Yes I had been warned off hacking the CPL especially with us being relatively new to this.

Regards

[carl]

I've had a bit of a look at this but it's not trival, sadly: suddenly deciding to process frames that aren't part of the actual DCP timeline breaks a few assumptions. I'll have a go but I can't make any promises!

[Carsten]

We had 'physical' and 'virtual' trimming in some versions of dvd-o-matic, I have a faint remembering of some discussions about it and how and why to keep it or not. I think for a time there was a checkbox or something to use either method. So, at least GUI wise, it would be possible to modify the trimming tab to support it with a checkbox (forcing even more options to decide upon...). The question always is, how will it affect other aspects of source assembly and, will it break something. I think when lining up video, audio and subtitles, there are many complex issues involved that users do not have the slightest idea about (and which caused many many issues in the past). While the idea of a virtual trim point itself looks simple, it may introduce a nightmare of complications.


This is very different from many other DCP mastering solutions which have established a reel based workflow right from the start, or are actually centered around that approach. The concept of DCP-o-matic is very different (and for a good reason), as it offers a much wider input format choice, and none of these formats are bound to reel segmentation. Technically, it is very important that DCP-o-matic is able to create reel based DCPs, but, there is no 'reel reeson' to have a reel based assembly workflow. Essentially, it is not part of DCI/SMPTE requirements. The only technical reason to have reels is in the final DCP, and then with subtitles, as there are some hard size limits for subtitles in reels.

- Carsten

[stefan]

Again thank you both very much for your replies.
Carl , appreciate you having a crack at it. Carsten your reasoning seems very sound and the approach DCPoMatic has taken is a good one.
It seems that when delivering a feature film you pretty much get asked to deliver every possibility once the list is in from every stake holder. It's a shame that it hasn't been standardised and minimised.
Regards
Stefan