Subtitles positioning

Anything and everything to do with DCP-o-matic.
Guddu
Posts: 159
Joined: Wed Oct 04, 2017 4:49 am

Subtitles positioning

Post by Guddu »

How important is it to specify a Vertical (Y) Offset for the subtitle position when creating a DCP without the subtitles burnt onto the image?

I am creating the DCP using the time coded .srt file. And I feel that in the dcpomatic preview window, the subtitle appears quite high on the screen.

Attached is an image that shows the subtitle area for a 2 line subtitle. It starts at around 750 pixels from top where it should instead be starting from around 850 pixels (I think).

How will this render on the cinema screen? Will it still show up as high as I am seeing in the dcpomatic preview? What is the best practice around this?
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barber
Posts: 65
Joined: Fri Apr 15, 2016 4:03 pm

Re: Subtitles positioning

Post by barber »

Hi Guddu,
Yes, the preview shows quite accurately what you'll see on a cinema screen.
You'll find there the offsets I use for subtitle size and height when working with a srt source: https://dcpomatic.com/forum/viewtopic.p ... 451#p14451
Another common practice is to use a SMPTE 428-7:2014 xml subtitle file with Arial 42 and VPosition at 7%. You can make those with the free Subtitle Edit for example.

Best,
Dan
Guddu
Posts: 159
Joined: Wed Oct 04, 2017 4:49 am

Re: Subtitles positioning

Post by Guddu »

Thanks Dan. I ended up using -11 as the offset and i maintained 100% in the scale :-) Looks neat. Did you reduce the size to meet some standard or was it your personal decision?
barber
Posts: 65
Joined: Fri Apr 15, 2016 4:03 pm

Re: Subtitles positioning

Post by barber »

My goal was to meet the common size of 42pt. Font size I've seen in DCPs are mostly between 38 and 42pt (the most frequent) but there is no mandatory standard.

Best,
Dan
Carsten
Posts: 3095
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: Subtitles positioning

Post by Carsten »

Guddu - I suggest you create an interop-DCP for a test and then look into the XML that DOM created - you will see the actual positioning that the projector will use. I don't know why the default is rather high, but you can depend on what you see on the preview window. I do see captions set as high as that regularly on main stream DCPs, though.
IoannisSyrogiannis
Posts: 376
Joined: Mon Nov 13, 2017 8:40 pm
Location: Iceland

Re: Subtitles positioning

Post by IoannisSyrogiannis »

And you can also see on some test patterns what the "safe" subtitles' area is, as well. It's relevant to what the image shows.

My take on that is that one needs to respect the fact that there are many screens out there where the projector is off-center and crop needs to take place. On top of that, arrangements for the subtitles to show horizontal and not cut. In such cases, DCPs or videos I have seen being extremely close to the lower visible line of the screen seems really... inconsiderable, in lack of another word that would be respectful.

One can treat their DCPs like they are screened on a screen similar to their monitor, but the realities vary a lot.