How to export caption track with alpha?

[POwens]

I have a fully-subtitled feature doc to turnover to finishing, and the vendor is requesting the subtitles as a separate TIFF sequence with alpha.   So - how to export a TIFF sequence?   I can export the sequence as a separate ProRes file with only the captions, of course, but can I get an alpha channel into that?   I presume they can always luma key it, but wondering if it's possible to do as requested?

[Ann Bens]

If you want a tiff sequence you need to send your timeline to AME and export the old-fashioned way.

[POwens]

OK, thanks for that.  But what about the alpha channel - is that automatically part of the export?

[Ann Bens]

If you open AME you will find a setting for the alpha channel.

[POwens]

OK, thanks Ann!

[POwens]

Following up.  This isn't practical, as each frame is 8MB, so at UHD, the group of TIFF files would be a few terabytes LOL.  Trying the ProRes approach, I turned off all video tracks except the caption track and tried exporting the caption track instead as ProRes 4444 out of AME, but the result is just black video - the captions do not export.   What am I doing wrong here?

[Stan Jones]

Captions are not graphics text as such, and I do not believe they can carry an alpha channel.

"Upgrade Caption to Graphic," was introduced with PR 23.1 - Dec 2022. Here is the What's New:

https://helpx.adobe.com/premiere-pro/using/whats-new.html

Select one or more captions, and PR converts them to graphics text and moves them to a video track.

If you want to also keep your captions, duplicate the caption track before you convert one of them.

Stan

[Stan Jones]

Also see this post with a tutorial:

https://community.adobe.com/t5/premiere-pro-discussions/when-will-adobe-allow-animations-in-automati...

Stan

[POwens]

Thank you Stan, this is super helpful.   I had been converting captions to text via srt -> XML conversions then importing that as a text layer, but this new feature removes all those steps.  Excellent!

[Stan Jones]

Yes, the XML conversions were a great method, but this is a big step in the right direction.

Stan

[POwens · Accepted solution]

Well, this worked a treat.   Convert to text, send to ME, export as QT > ProRes 4444 8bit + alpha - worked as desired.  Thank you Stan

[Stan Jones]

Excellent!