AFAIK BSPlayer display subtitles as long they are defined by the number of frames or by the time to be displayed , depending on type of subtitle.
(100)(200)How are you
Will remain displayed for about 4 sec at 25 fps
(100)(125)How are you
will remain only 1 sec at 25fps and 0.8 sec at 30 fps.
All is depending on the one whocreated the subtitle file.