Might seem highly technical at first when reading it, but in fact the idea is fairly simple.

What's the purpose?
Well, having a PS3 now, I'd like to watch my mkv files with it on the nice screen attached.

You all know PS3 isn't compatible with mkv files, and should it someday be compatible, I do not see it decoding ASS subtitles. The only way would be a homebrew firmware, but that will probably happen when the PS3 has become obsolete, since I guess hackers need access to PS3 internal industrial secrets Sony isn't willing to give away easily.

BUT, maybe there's another way of having high visual quality subs.

From what I understand, the PS3 is now compatible with IDX subs, that are in fact bitmaps/images.
The PS3 is compatible with transport stream files incorporating subs. Video stream in TS files can have high quality video profiles (up to AVC 4.1).

So in theory, one could just extract the ASS subtitles, transcode them to IDX and mux them in a TS file without even transcode the video or sound...
Which is great because transcoding is awfully slow and degrades quality... not doing it saves time and quality.

So next step is finding a nice way of transcoding the subs to nice bitmaps that will save the visual aspect of the original ASS subs, then mux that.

Does someone know of software doing so? I guess some of you already tried to play with that? if so, thanks for sharing.
I will continue to search for ways of doing it and should I find something, I'll post my results here.

Have a nice day.