“Arrival” is not your typical sci-fi blockbuster. Just when you think you know what will happen, events change as quickly as Earth’s outlook after extraterrestrials arrive. Amy Adams stars as a hotshot linguist who must figure out a way to communicate with the aliens amid threats of a global war. But what she finds might leave some viewers with more questions than answers. Extras on the Blu-ray, out Tuesday, detail rarely covered topics such as the film’s cool sound design, scoring and linguistics.