How can I create a .SUP subtitle file from scratch?

[Radiocomms237]

.sup seems to be the main subtitle format used on Blu-ray discs.

I can rip .sup files with MakeMKV, I can slice them up with MKVmerge, and I can convert them to pretty-much any other subtitle format with the OCR-capable subtitling program I use, but I've searched & searched and I can't find any software which allows me to create a .sup file from scratch.

I've tried half-a-dozen different programs but the main subtitle editor I use is "SubtitleEdit", it will open/OCR .sup files but not create/output them.

I found a little program that is supposed to convert .sub files to .sup, but I can't get that to work, It wants an .idx file, which I don't have.

I realize that .sup subtitles are graphic-based, and I'd even be prepared to create all the individual images by hand (although I'd really prefer not to), but I can't find a way to compile them into a .sup file.

There MUST be software that can do it. I mean, these files do actually exist on Blu-ray discs so somebody must have the capability of creating them?

If someone could suggest a program I could try, I would be grateful! I don't even care if it's not freeware, I'm happy to pay for something so long as it actually works.

[dcoke22]

Software like Final Cut Pro can create videos with subtitles and output things in blu-ray format. I'm guessing that's not what you're looking for however.

Some folks on the VideoHelp forum have suggested tsmuxer could be used to convert a .srt to a .sup. Since .srt subtitles are plain text, they would be easy enough to create, assuming tsmuxer really can do what is suggested.

[ArArdin]

...the main subtitle editor I use is "SubtitleEdit", it will open/OCR .sup files but not create/output them.

Yes, it does. And it has better results over tsMuxer's SUP creation. It does not matter whether you have OCR'd image-based subtiles into srt, or you created srt from scratch, or opened any text-based subs. Once in SE, go "File --> Export --> Blu-ray SUP..." The export window offers a lot of options, including dynamic preview. Be sure to set the correct framerate.

Note that on UHDBD, SUPs for 4K video are authored in 1920x1080 videoresolution. Also, darker colors (or greyscales) are used for HDR SUPs.

[Radiocomms237]

Oh, that is just awesome!

I was about to praise tsMuxeR because I'd finally figured-out how to get (almost) the result I was after, but this option in SubtitleEdit just blows tsMuxeR out of the water!

I had only previously looked at SubtitleEdit's "Format" drop-down box and couldn't see an option for .sup but now I think about it, "Export" makes much more sense.

Plus it has the option to place a background and shadowing as well, which I couldn't find in txMuxeR. And it allows each individual line to be formatted instead of one setting for the entire file.

The only setting I can't find in SubtitleEdit is "Forced", on Blu-rays, as I'm sure you know, individual lines of subtext can be set to forced but I don't see that option anywhere. Do you know if that's possible?

[Radiocomms237]

DOH! Never mind, I just saw the checkbox at the beginning of each line.

Thanks again!

EDIT: Scratch the part about formatting each individual line as well, now I've had a bit of a play, it seems the "Image settings" are global and it's only "Forced" that you can set on a line-by-line basis.

[ArArdin]

Good you figured it all out.

tsMuxer is a tool that focuses on muxing. Having built-in the text to SUP converter definitely suits the devs. And to lots of users it will suffice.

Myself not excluding, I think a lot of Subtitle Edit users aren't aware of all its capabilities. It's immensely comprehensive and SE's author Nikse doesn't stop working on it. Using it for years, it keeps surprising me.
You should definitely check out the SUP editor. If OCR or extended image-editing aren't called for, it's incredibly handy for editing other properties like syncing timings/framerate, changing offsets/position coordinates, forced flags, etc. It does provide with a few simple, but much called for image processings. My personal favorite is brightness adjustment. Immensely convenient for curbing on luminance of SDR targeted SUPs to suit usage with HDR video.