An operating section receives a first operation relating to a group display position that is a position of display videos formed by a plurality of videos belonging to a video group on a multivision screen, and a group display size that is a size of the display videos. A display controller determines video display positions that are positions of the plurality of videos on the plurality of display screens and video display sizes that are sizes of the videos based on the group display position and the group display size, display information including sizes and positions of a plurality of display screens, and a relative position and a relative size of the plurality of videos in the video groups, generates video signals for the plurality of displays based on the video display positions and the video display sizes, and outputs the video signals to the plurality of displays.