Does an export with added subtitles alter the quality of the video?

[LJAGB]

Hi,

I have a clean DCP that I want to export with added subtitles (srt file).
I'd rather burn the subtitles in, to make sure the result is 100% reliable.
Does the new export risk altering the quality of the video?

Many thanks for your help

[Carsten]

With burn-in, yes, you will have a slight reduction in quality, because in order to burn-in, a full recompression needs to be performed. If you use a decent data rate setting, it will usually not be noticeable, though. You could try a short piece with complex content and check it yourself in DCP-o-matic player.

Do you use an unusual language, special chars for the subtitles? Because, if it's a plain vanilla font and charset, timed-text is reliable. Is this a full length feature? Splitting it up into a few reels might improve timed text reliability further.


- Carsten

[LJAGB]

Hi Carsten,

Thanks a lot for your reply.
It's a short film.
I have to export it with double subtitles (French + English > 2 srt files) and the two subs need to be a different colour (white / yellow).
I'm wondering about the best way to go about this.
Should I burn the English subtitles in and have the French subtitles as timed-text? (In which case, is there a risk of the two not being perfectly synchronised?)
Or is there a more efficient way?

Thanks again!

-L

[cvila]

IMO in that special case I would go with burned-in.

[Carsten]

I'm pretty sure this will work with timed text. When adding two SRTs and placing them parallel each other (->Timeline View), DCP-o-matic will compile a single XML file, and the result will technically be a single subtitle file, using different colors, which is completely normal. You just need to adjust the height of the titles per SRT file, so they don't intersect with each other (and maybe try not to use more than one active line per title).


I once checked a short for a film maker who thought that cinema servers would allow to select individual subtitles from one DCP containing multiple subtitles - so he put all 8 languages into a single DCP-o-matic project. And, on both our servers (Sony and Barco), all 8 simply showed on top of each other simultaneously.


Of course, it is easy to do both, timed text and burn-in, from within the same project.

- Carsten

[LJAGB]

Dear Carsten,

Thank you so much.
The part I was missing was placing the 2 SRTs parallel to each other in Timeline view.
When I first tried adding 2 SRTs, the film's running time changed and I thought it was because DCP-o-matic couldn't support more than 1 SRT at a time.
This is going to save me a lot of time in the future, and I'm glad I can use the original DCP without reexporting it.

Thanks again, you're the best!

-L