Hearing impaired captions

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binba
Posts: 11
Joined: Thu Jul 04, 2019 3:56 am

Hearing impaired captions

Post by binba » Sat Sep 07, 2019 2:30 am

I'm authoring a feature film DCP and trying to think ahead about hearing impaired subtitles. This is for an indie film in the festival circuit, so there are no hard and fast requirements, but some festivals ask for it. I have SRT files.

Open captions
1. The director is adamant to have a semi-transparent gray box behind the captions, so PNG would be the way to go. I know I can make it work, but in the real world of 2019, is this a stable feature on most projectors, one that projectionists know how to handle, and not a source of confusion of mistakes?
The alternative is to author a separate DCP with burnt-in captions to those who want it.

Closed captions
2. Those have to be textual (SMPTE-TT) in order for optional external devices to utilize them, correct?

3. Does DOM allow having both open and closed captions alongside each other in a DCP, and projectionists can utilize them independently?

4. Do I have to just trust the projectionist to project the PNG OC track, and not the SMPTE-TT CC track (that the projector will render), and only use the latter if they have an external system?


There's a lot of cool things that DCPs can do - but I'm trying to plan which features I should use, taking into account the human factor, prevalent firmware etc., to ensure a smooth experience. This isn't a premiere I can attend and test in person, but random small festivals around the world where it should "just work".

Carsten
Posts: 1397
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: Hearing impaired captions

Post by Carsten » Sat Sep 07, 2019 11:03 am

The idea in DCI is that all elements of a CPL are 'mandatory' during playout. That means, you supply a CPL, and everything contained/addressed in it will be played/used for the presentation. Therefore, e.g. timed-text/open captions can not be disabled at will by the projectionist.

Okay, for closed captions, if the cinema doesn't supply the glasses, or nobody uses them, then obviously, closed captions are NOT mandatory.
But closed captions/HI/VI-N are supplied to the individual, not the common majority of viewers.

PNG, when used traditionally, work solid. No 4k in Interop (it's complicated for the server/projector combination to scale image and superimposed png for different combinations of 2k/4k server playout/projector resolutions).

Small festivals sometimes use software players (like NeoDCP, or other solutions), and playback of ClosedCaptions, PNG subtitles, etc. is not guaranteed with these.

- Carsten

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