 to the priming samples (or the padding at the beginning) derived from the pre-roll for the startup and the
        padded samples at the end, we need trim from media to get the actual duration. An edit in the Edit List Box can
        achieve this demand, and the Edit Box and the Edit List Box shall be present.

        For sample-accurate trimming, proper timescale should be set to the timescale field in the Movie Header Box
        and the Media Header Box inside Track Box(es) for Opus bitstream. The tim