To make localisation of cutscenes easier, it would be great if you would to add two features to the Theora Playback:
a) subtitle string expansion
If subtitles use the talk format ("/CUTSCENE_01_01/Hello, I'm a subtitle"), the string gets expanded using the active string table.
This bundles all translations to a single file, string.tab, which makes handling easier for translation management.
And, multilingual games can change the string.tab, but they cannot change the .sub files, so the subtitles in theora would be in the original language even if another language is selected.
This leads to:
b) explicit subtitle file parameter
Please add a fourth parameter to PlayTheora(), "subtitle file". If this is not given, the default filename is used (for example, "theora.sub" for "theora.ogg")
This can be a standalone solution to the translation problem, not as elegant as a), but working.
If you combine a) and b), it is possible for the developers to have their string.tab-files translated and switch them at startup. If, and only if a language needs other cue points, another subtitle file can be selected, not changing any strings, but changing the cue points.
This adds more flexibility for developers using string tables in languages they do not understand themselves, for they cannot shorten the lines in this string.tab files. Well, they could, but ... they shouldn't ;-)