I have two movies, both using MKV containers, each has an SRT file with Simplified Chinese that can be read with GB18030 encoding via LibreOffice. So I assume they have the same or at least very compatible encodings.
Movie A's subs play just fine on both PC/Ubuntu and on Mac Mountain Lion.
Movie B's subs give mostly "?" with a few boxes and random chars.
I renamed A.srt to B.srt and vice-versa as an experiment. Clearly the subs now belong to the wrong movies, but bear with me.
Movie A can play subs, regardless of which source movie the subs belong to.
Move B cannot play subs, regardless of which source movie the subs belong to.
Thus, I infer that there is something in the MKV messing things up.
I've tried manually loading the subs, I've tried switching to all available subtitle tracks. No joy. What could possibly be in the MKV that is confusing VLC? More importantly, how do I get it fixed???