Adding chapter points manually
To add a chapter point to a movie:
Alternatively, right-click anywhere on the timecode ruler and choose Add Chapter from the shortcut menu. A new chapter point is added at the point where you clicked the timecode ruler.
Note: If the movie has an MPEG video track, DVDit Pro places chapter points at the closest GOP boundary to the playhead location. This could be up to nine frames from the playhead in an NTSC project or six frames in a PAL project, depending on the GOP size.