[MPlayer-users] splitting subs accurately with mencoder

[HR]

I've been pondering about the best way to do this, and can't figure it
out.

I use mplayer/mencoder, creating a 1400MB rip of some DVD. Then I use
avidemux to split the file in two 700MB pieces for a nice CDR fit.

Now, extracting the subtitles using mencoder is a pretty
straight-forward task, but how do I split the subtitles to match the cut
I made with [some cutter tool]? I've tried -ss/-endpos with no luck; the
cd2 part of the subtitles is way off - due to the DVD resetting the time
at some chapter boundary or what-not. Whatever the reason, I guess
time-seeking is broken, as discussed elsewhere. A -sb/-frames
combination could maybe do the trick, but then how do I figure out what
bytepos in the VOB matches the cut point at the cd1/cd2 boundary? ie,
how do I find what (exact) bytepos in a VOB a certain frame corresponds
to? I have the whole movie in a single VOB, using -dump* as discussed
elsewhere, so working with bytepos and frames should be simple. Is the
bytes/frame constant in such a VOB?

The best would be to have something like -startframe/-endframe or
-startframe/-frames (to atleast keep one existing parameter), but no
such thing?

HR