Fixed a few copypasta errors in MP4 lib.
Fixed a few copypasta errors in MP4 lib.

DDVTECH/mistserver,rbouqueau/libdtsc_xp,rbouqueau/libdtsc_xp,rbouqueau/libdtsc_xp,DDVTECH/mistserver,DDVTECH/mistserver,DDVTECH/mistserver,DDVTECH/mistserver