Subtitles in Indic/Arabic/other scripts requiring CTL

My father (Dr T Vasudevan, cc-ed here) is working on a spoken (actually
video) tutorial project using Indian languages as the instruction
medium. He would like to add Indic language subtitles in (obviously)
Indic scripts. For now, Tamil, both as the language he is working on (as
it is our mother tongue) as well as the Indic script which is simplest
in terms of CTL.

However it seems current video players (at least two OSS ones -- MPlayer
and VideoLAN that they are using in that project) do not support CTL.

In speaking about this with another friend of mine he was wondering
whether Arabic people have worked on getting Arabic subtitles, as it
would also involve CTL.

Can anyone shed light on CTL in subtitles? Perhaps Arabic or hopefully
Indic?

-- 
Shriramana Sharma