A method of processing a digital broadcast signal for a 3-dimensional, 3D, service, the method comprising: encoding video data for the 3D service into a video stream, the video data comprising a left picture and a right picture for a 3D image; generating the broadcast signal having the video data and service information for the 3D service, the service information including a video depth range descriptor indicating a minimum disparity and a maximum disparity that occur during a given time window of the video stream, wherein the minimum disparity and the maximum disparity are a minimum difference and a maximum difference between horizontal positions of a pixel representing a same point in space in the left and right views of 3-dimensional image, respectively, wherein the video depth range descriptor further includes scene identification information identifying each scene of the scenes, wherein the video depth range descriptor further includes a scene format type field identifying a method for applying the minimum disparity and the maximum disparity in each scene, wherein a first value of the scene format type field indicates that the scene is defined by a constant length video segment, the length of which is defined by a scene duration field comprised in the video depth range descriptor, wherein the scene duration field indicates a time length representing the duration of the corresponding scene, wherein a second value of the scene format type field indicates that each scene has a variable duration defined by a scene start time field and the scene duration field comprised in the video depth range descriptor, the scene start time field indicating the start time of each scene; transmitting the digital broadcast signal for the 3D service. encoding video data for the 3D service into a video stream, the video data comprising a left picture and a right picture for a 3D image; generating the broadcast signal having the video data and service information for the 3D service, the service information including a video depth range descriptor indicating a minimum disparity and a maximum disparity that occur during a given time window of the video stream, wherein the minimum disparity and the maximum disparity are a minimum difference and a maximum difference between horizontal positions of a pixel representing a same point in space in the left and right views of 3-dimensional image, respectively, wherein the video depth range descriptor further includes scene identification information identifying each scene of the scenes, wherein the video depth range descriptor further includes a scene format type field identifying a method for applying the minimum disparity and the maximum disparity in each scene, wherein a first value of the scene format type field indicates that the scene is defined by a constant length video segment, the length of which is defined by a scene duration field comprised in the video depth range descriptor, wherein the scene duration field indicates a time length representing the duration of the corresponding scene, wherein a second value of the scene format type field indicates that each scene has a variable duration defined by a scene start time field and the scene duration field comprised in the video depth range descriptor, the scene start time field indicating the start time of each scene; transmitting the digital broadcast signal for the 3D service.