Is it possible to use SSA/ASS for captions rendering?

[lyra-white]

Hey, this seems like a nice lib. I have some experience using SSA/ASS file format for captioning.

I discovered mpv recently through this issue: mpv-player/mpv#15711, which was linked to libass's rounded corners for captions: libass/libass#688

I apologize for my ignorance on knowledge and understanding of mpv. My understanding is that mpv uses SSA/ASS format for captioning, but also has a bunch of additional hooks to further customize the captions. Skimming through mpv documentation, I could not find a conceivable way to directly use ass files or for that matter have rounded corners for my background.

I am wondering if there is a way to achieve rounded corners for background using this library. I am looking to hard-burn generated captions with rounded corners for background on to the video.

WDYT?