PNG timed-text - subtitles

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Joined: Thu Aug 18, 2016 12:08 pm

PNG timed-text - subtitles

Post by skiff » Sat May 04, 2019 10:03 am

Carl thank you for this option!! :D
I would like to test it.
How can I import the PNG? Do you have recommendations for good software to build the PNG subtitles?
Hope to work with this feature!
Thank you again.

Posts: 1218
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: PNG timed-text - subtitles

Post by Carsten » Sat May 04, 2019 7:31 pm

I think currently the only ways to add PNG subs is by adding VOB/DVD subs (bitmap subs) with the source video, or by adding them as a DCI compatible folder of PNGs and an accompanying XML file - basically, the same what DCP-o-matic creates for PNG subs in DCPs.
What I just tested was converting a short piece of a subtitled DVD to Timed PNG, and then tried to reuse the resulting subtitle folder containing the XML and PNGs in a new project. Basically, you choose 'Add file', then select the XML containing the PNG timing. Worked without issues. At least I tested these two methods myself.

I would think that the SMPTE version, an MXF containing the PNGs and XML, would work just the same. I don't know which software currently is able to supply these formats. At least subtitle edit quotes:

'Export to PNG images (+bdn xml), Adobe Encore FAB image script, VobSub, Blu-ray sup, EBU stl, PAC, and plain text'

So I guess it wouldn't be too complicated to support the DCI PNG format as well. Maybe you should suggest it.

The attached examples are from a DVD/VOB.
These PNGs are all different resolution RGB+Alpha PNGs. Their resolution should match the DCP resolution, e.g. 1340 wide (max 2k wide) for a 2k DCP.
I think you could just as well have all PNGs with the same raster format (e.g. 2048*120) and the subs placed within them.

As far as I know, PNG is not possible/allowed for 4k DCPs in Interop format. I know a commercial high profile DCP created that way showed display problems on many servers/projectors. When they issued a new DCP to correct the issue, it used classic timed-text.

- Carsten
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