Is Kate Still a Thing?

[wswartzendruber]

I've been investigating the most robust way to rip graphical PGS subtitles into Matroska. I'm in the mood to study spec sheets and write code. I want to be able to adjust scale and crop, after all. But I'd like to rip to a well-supported, royalty-free format. You can call it idealism, if you like.

So here's the rundown:

1. SRT - text only
2. ASS - doesn't support PNG and mkvmerge supposedly converts file attachments to be separate Matroska attachments.
3. USF - graphical support was never added.
4. PGS - proprietary, and I can't find any documentation saying Matroska officially supports this
5. Kate - supports text, graphics, and everything under the sun

The problem I have with Kate is that I can't get anything with Kate subtitles in them to actually show up in either VLC or Kodi. Elephant's Dream is available with Kate subtitles and they don't show up even when I select them. I muxed my own that I converted from SRT using kateenc, and those don't appear, even though the language code shows up in the subtitle selection.

Kate seems like a silver bullet for all subtitle use cases but nothing wants to show it. What gives?