(in alphabetical order)
... and more generic timed text and transcript formats. Some file types come in flavors (e.g Titra) currently not every flavor is supported.
(in alphabetical order)
Avid (ALE)
Avid DS/Subcap (txt)
Blue-Ray BDN (xml, images)
Cavena (cip, mtl)
Closed Caption (scc, mov)
CMX 3600
DLP Cinema (xml)
DVD Studio Pro / Spruce STL (stl, son, rtf, images)
DVDit/Pro (txt)
EBU (stl)
Encore (txt, images)
Excel (xml)
FAB Text (txt, images)
Final Cut Pro (xml, images)
Final Cut Pro batch list (txt)
Gelula (das, dat)
Google Transcript (xml)
Plain Text (rtf)
QuickTime Chapter (mov, txt)
QuickTime Subtitle (mov)
QuickTime Text (mov, txt, SMIL)
RealText (rt)
SAMI (sami)
Smoke (xml)
Sonic (sst, images)
SubRip (srt)
SubStation Alpha (ssa)
Swift (sif)
Tabbed Text
Timed Text (rtf, doc)
Titlevision 2003 (txt)
Titra (rtf)
Universal Subtitle Format (usf)