the subtitle format defined in the mpeg-4 standard (part 17) is mpeg-4 timed text
it can be used already inside the mp4 container and haalis mp4 parser also already supports it
i noticed that bsplayer still doesnt understand that format it gets passed from the haali parser
also it seems to have problems playing vobsubs inside the mp4 container from the haali parser
you can get the haali parser here:
http://haali.cs.msu.ru/mkv/
sample files here:
http://www.8ung.at/bond/timedtext_mp4box.zip http://www.8ung.at/bond/timedtext_mp4box2.zip http://www.8ung.at/bond/ttxt_missingsample.zip