The present invention provides an apparatus for transmitting a video stream, an apparatus for receiving a video stream, a method for transmitting a video stream, and a method for receiving a video stream. One embodiment of the present invention, discloses the method for transmitting the video stream, comprising the steps of: down-sampling a UHD (ultra high definition) video stream to divide the UHD video stream into a sub-stream of a viewable HD compatible video, a sub-stream of an HD-sized video, and a sub-stream of a residual signal as a difference between the HD compatible video and the HD-sized video, and encoding the divided sub-streams; multiplexing signaling information for describing the relationship between the UHD video stream and at least one sub-stream and including the sub-stream; and transmitting the multiplexed HD sub-stream and the signaling information.