Division editing of a movie stream file picked up for a recording application is executed while conforming to a predetermined standard format.When a stream file is divided at an arbitrary division point, a preceding chapter is created by giving padding in an end region of a GOP including the division point in accordance with a length alignment restriction. Furthermore, a first extent of a succeeding chapter is created by copying the GOP including the division point and a GOP immediately succeeding it, a region formed of GOPs after the copied portion is used as a second extent of the succeeding chapter, and padding is given to an end region of the second extent in accordance with the length alignment restriction.