Subtitles and font size limit in 2024?

[cvila]

You all talk about upper limit, but I recently got a DCP rejected because my font was BELOW 200kB.
Have you ever seen that before?

[Carsten]

Never.


I have seen commercially mastered DCP with fonts much smaller than that.There are many many TTFs much smaller than 200KByte.

[Schmidt]

You all talk about upper limit, but I recently got a DCP rejected because my font was BELOW 200kB.
Have you ever seen that before?

I wonder what kind of validation tool was used to determine that the font should be rejected? Or if it was a random
"tech guy" that looked at the .ttf file and did his own judgement call based on it's size.

Ask them provide more exact information. If you are sure the font is ok - request for the DCP to be un-rejected.

[Greg3o3]

I believe there is still a limit in place of 640KByte per reel for font AND XML combined. This may only apply to series 1 projection systems, but they are still around in serious numbers.

Hi Carsten,

I do have a stupid sounding question regarding what you said. I am creating a feature SMPTE DCP and the closed caption's XML file is 420kB (tons of talking). The font I am using is 92kB. DoM reminded me that the XML is larger than 256kB. However by 640kB combined (font+XML) does it mean that as long as I am under the 640kB limit the XML can be larger than 256kB? And if not, how likely is it that the venue gets an error message because of the size of the CC's XML? (I am thinking into splitting the film now into 3-4 reels, however I've never done it that way. Will the playback be seemless?)
Sorry about all the silly questions, just wanna make sure I am sending the venue a DCP they can definitely play.

Thanks.

[Carsten]

I am sorry, it seems because of a holiday trip, I did not answer this question back then. And maybe I shouldn't, because I don't know for sure.

But what I can say is:

The problem is that the technical capabilities of the different subtitle rendering techniques of the installed cinema equipment is not properly documented, and companies mastering subtitled versions learnt their limitations the hard way when their DCPs did not work as expected. This is also the reason why still today burn-in subtitles are used relatively often, because they always work.

Some of these recommendations target specific different types of equipment, a classification many people outside the cinema industry can hardly follow, namely series-1, series-2, Sony, server-side subtitling, and then the spread of series-2 follow-up platforms often called series-3, series-4. Typically, modern machines have better subtitling capabilities than series-1 or series-2, and series-2 improved a lot with software updates over time. Most systems installed as of today (2024) are series-2.

Also, one should read recommendations thoroughly and not confuse them - the 256kByte limit to my knowledge only applies to 'Closed captions', not open subtitles. But because sometimes the same timed text files will be used for open AND closed captions/subtitles, the easy recommendation would be to limit the file size for BOTH applications, though not strictly necessary for open captions/subtitles.

I suggest reading these recommendations:

https://hpaonline.com/wp-content/upload ... 0314-2.pdf

https://pub.smpte.org/pub/rdd52/rdd52-2020.pdf


Aside from all this - it is REALLY safe to split your DCP into reels. DCP-o-matic will do this based on precise frame and audio sample numbering, and almost all commercially mastered DCPs use multiple reels for video, audio and timed-text. They WILL play seamlessly in cinemas.