According to one embodiment, a basic format for a 3D signal having a first area to arrange main video data, a second area to arrange graphic data, a third area to arrange depth information of pixels of the main video data, and a fourth area to arrange depth information of pixels of the graphic data are defined. When depth information of pixels of the main video data is generated, a 3D processing module can select whether to use a first pattern obtained by inserting the graphic data into the main video data and a second pattern obtained by not inserting the graphic data into the main video data. A 3D related controller decides on the first or second pattern to be used by the 3D processing module.