Adding SRT to existing DCP

[jimmy90]

Hello,

I've been given a request to add an srt file to an already existing, encrypted DCP. Is this possible? If so, how would I go about doing that?

Thank you,

[carl]

You're would need a DKDM for the encrypted DCP, or the cooperation of whoever makes KDMs for it. Do you have that?

[jimmy90]

Hi carl,

Thank you for the speedy response. Yes, we are able to get the DKDM. What would be the process after that?
(Apologies if that's an amateurish question. It's been a while since I've worked with any DCPs, let alone encrypted ones)

[Carsten]

You create a new project, add the encrypted DCP, add the DKDM, add the SRT File, adjust subtitling settings, and, either create a new OV (encrypted, if needed), or a new VF (encrypted if needed). Then after all is done you would probably also need to create a DKDM targeted at the rights owner (or whoever created the DKDM for you). For the latter to do, you need to request 'their' encryption certificate. So they can continue to create their own KDMs for the encrypted title with the subtitles.

Depending on your experience with DCP-o-matic, we can guide your through it more detailed. DCP-o-matic allows to learn all the steps in an easy way. e.g. just create a new project, and add e.g. just the SRT file for now. You can already see the subtitles (if you enable them) over a black background. Continue from there.

- Carsten

[jimmy90]

Hi Carsten,

Thank you for the response. Adding the srt to the DCP seems simple enough, however I don't fully understand the latter part.
Creating a new DKDM from my end makes sense but I'm not sure how requesting an encryption certificate from them works into that process?

Again, I haven't done this before so speak to me as though I'm a complete beginner. I won't be offended

[Carsten]

If you create a new encrypted DCP, you can not re-use the previous decryption key of the non-subtitled DCP.
If you are creating the subtitled DCP for the original DCP 'owner' (rights owner) as a service, you need to enable THEM to create their own KDMs for the subtitled version. Otherwise, they would need to request all future cinema KDMs for the subtitled version from YOU. This is again, assuming that you do this as a service for them. So, you would need to issue a DKDM towards the party who is to create future KDMs for this encrypted subtitled version. The way to do this is to request a certificate from them. This is the same process as when you receive a DKDM from them in order to 'open' the original encrypted DCP - they have to request the cert from your DCP-o-matic installation.

If you want to create the subtitled version only for yourself (e.g. to show it in your cinema, during your festival, whatever), then of course the rights owner wouldn't necessarily need the ability to create their own KDMs in the future. In that case, the new subtitled DCP would not necessarily have to be encrypted at all (if the rights owner is okay with that).

[jimmy90]

Okay I'm much clearer on what's required, thank you.

If I run into any issues I'll return to this thread.

[jimmy90]

Hello,

I come back with another simple question. Once I've added the srt file and have to create the new DCP, will it be as lengthy a process as it would be creating a DCP from scratch or is it the case that it just adds the subtitles to the already encoded video and it's a much shorter process? I hope that makes sense.
This just so I can provide a rough idea on how long it will take to make.

Thank you,

[Carsten]

If you created the DCP without subtitles beforehand, and then create another DCP with the subtitles, it will go very fast - a couple of minutes. Only if you choose to burn-in the subtitles, all the images have to be recreated/recompressed, and it will take as long as during the first run.