i use mp4box to create video files with multiple audio and subtitle tracks each.
i have subtitles which only play for short moments (like when elvish is spoken in lord of the rings). i want these subtitles to be displayed when the video is launched (i use mpc-hc, but the solution shouldnt be specific to that).
the user may then switch to full subtitles or another language, but i want this one subtitle track to be active by default.
is there a way to do that (except encoding them to the video itself)?
if not, is this a limitation of mp4box or of the mp4 container standard?
researching this i found the -enable option, which doesnt seem to change anything, and i found the concept of "group" which i havent understood yet. can that actually group tracks together so that when i change the audio language the subtitles for the elvish parts change language too (like a dvd would behave)? if not by group, can this be achieved in any way?