First off I need to explain that the srt support comes from converting the .srt file into .xml
The xml structure that must be achieved is the following:
and the source XML is here: sample.xml
If I can convince my friend that did the conversion script from .srt to XML to release his code I will post it here too. But it should not be difficult just make sure to convert frames into seconds. (Flowplayer captions plugin source code can help a lot with this).