Film-Tech Forum ARCHIVE: Subtitles not showing on a Christie but shows on Barco

This is topic Subtitles not showing on a Christie but shows on Barco in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=16;t=002995

Posted by Konstantin Victoria (Member # 9128) on 03-31-2017, 09:19 PM:

This may be a little confusing.

We received a drive similar to another location. The version file contained in the Hard Drive is only a CCAP version. The other sites were able to display subtitles perfectly fine on the CCAP version. Our Christie CP2220 projectors won't show any subtitles, but for OCAP versions they display subtitles perfectly fine. However, our Barco (which is running on a Dolby Server) is able to show the subtitles. The only peculiar things I've noticed is that the Christie takes a while to play the film. It usually "Checks if DCI Compliance" for a good 20 seconds.

Are there any options on the GDC or Christie that I may change to allow that?

Posted by Harold Hallikainen (Member # 5405) on 03-31-2017, 10:45 PM:

Generally, a server is supposed to obey the CPL. If the subtitles or captions are "open," they are supposed to be on screen. If they are closed, they are only supposed to show up on private displays. Also note that captions and subtitles are not the same. See http://isdcf.com/papers/ISDCF-Doc10-Subtitles-and-Captions-in%20Digital-Cinema-20160211.pdf .

Some servers may allow you to override some of the CPL, though I don't think they are supposed to. In general, the server should obey the CPL and you should choose the CPL that has the features you want.

Good luck!

Harold

Posted by Konstantin Victoria (Member # 9128) on 03-31-2017, 11:37 PM:

Hi!

Thank you for your input. I did go on the GDC to override cpl and force the GDC to process the subtitles instead of the projector. However, there were artifacts right below the subtitles that began showing up. They look like dead pixels on a monitor.

Posted by Leslie Hartmier (Member # 7053) on 04-02-2017, 08:00 PM:

I am somewhat confused, yes.
You are wanting to make CCAP display on the screen?
By subtitles, you are running a feature that needs subtitles (the feature is in a foreign language, or you need OCAP)?
You have *legitimate* subtitles (not captions), and they are NOT displaying on screen?

As Harold said, if it's not open captions or actual subtitles that are supposed to be on screen, the projector will not process them unless you force it to, and neither will the content server.

I have discussed using the content server for subtitles with GDC before, and their response was pretty clear - processing captioning/subtitles using the GDC content server is not optimal, as it is forcing the content server to do something that the projector (or at least most projectors anyway) can do easily (they literally have a thing called the Subtitle Engine), which puts more load on the content server, and forces the IMB to pass along the subtitles, which might explain the artifacts.

Anyway, strictly speaking, if you are referring to captions, CCAP is not supposed to display on screen, but only on third party devices, OCAP is not supposed to show on third party devices, but only on-screen, subtitles are supposed to show on-screen (but I suspect you are trying to make closed captions show on screen, and what might be happening there is that you are using the content server to redirect the closed captions from its channel to the screen.)

As for the 'Checking for DCI Compliance,' are you referring to the content server (the Dolby/GDC), and not the projector (Barco/Christie)?

Incidentally, which Dolby content server and which GDC content server are you using?

I might be completely offbase on this, and if I am, please explain what you are trying to do, and hopefully we can help with it.

Leslie