A video generation device comprising: a video acquiring unit that is arranged on a vehicle and is configured to acquire videos that are captured by a plurality of imaging devices (11,12,13,14), at least one of the imaging devices being mounted on a door of the vehicle that is movable with respect to a body of the vehicle; an information acquiring unit configured to acquire detection information indicating that movement of the door is detected; a video generating unit configured to generate a synthesized video by synthesizing the videos that are captured by the plurality of imaging devices (11,12,13,14) and are acquired by the video acquiring unit; and a display control unit configured to display the synthesized video generated by the video generating unit on a display unit, wherein when the information acquiring unit acquires the detection information indicating an opened state of the door, the video generating unit generates, as a synthesized image including a video with orientation changed in accordance with a direction in which the door is opened, a bird's eye view video in which the vehicle is viewed from above by performing a viewpoint conversion process on orientation of a video that is captured by the imaging device mounted on the door in the opened state, wherein the information acquiring unit acquires detection information indicating that movement of the door detected and an open level of the door, and the video generating unit, when the information acquiring unit acquires the detection information indicating the opened state of the door, generates a synthesized video by changing orientation of the video that is captured by the imaging device mounted on the door in the opened state in accordance with the open level of the door. a video acquiring unit that is arranged on a vehicle and is configured to acquire videos that are captured by a plurality of imaging devices (11,12,13,14), at least one of the imaging devices being mounted on a door of the vehicle that is movable with respect to a body of the vehicle; an information acquiring unit configured to acquire detection information indicating that movement of the door is detected; a video generating unit configured to generate a synthesized video by synthesizing the videos that are captured by the plurality of imaging devices (11,12,13,14) and are acquired by the video acquiring unit; and a display control unit configured to display the synthesized video generated by the video generating unit on a display unit, wherein when the information acquiring unit acquires the detection information indicating an opened state of the door, the video generating unit generates, as a synthesized image including a video with orientation changed in accordance with a direction in which the door is opened, a bird's eye view video in which the vehicle is viewed from above by performing a viewpoint conversion process on orientation of a video that is captured by the imaging device mounted on the door in the opened state, wherein the information acquiring unit acquires detection information indicating that movement of the door detected and an open level of the door, and the video generating unit, when the information acquiring unit acquires the detection information indicating the opened state of the door, generates a synthesized video by changing orientation of the video that is captured by the imaging device mounted on the door in the opened state in accordance with the open level of the door.