A transmission apparatus, comprising: an image encoding unit adapted to perform hierarchical encoding on image data of pictures constituting moving image data and to generate a first video stream including the encoded image data of the pictures on a low hierarchy side and a second video stream including the encoded image data of the pictures on a high hierarchy side, the encoded image data having a network abstraction layer, NAL, unit structure, a level specification value of the first video stream being inserted into a NAL unit of a sequence parameter set, SPS, of the first video stream; and a transmission unit adapted to transmit a transport stream including the first video stream and the second video stream generated in the image encoding unit, stream identification information as a degree-of-priority information that is set to be higher for a hierarchy group on a low hierarchy side and indicating a hierarchy group to which the encoded image data of each picture included in each video stream belongs, and for each stream a first descriptor into which the level specification value of the video stream is inserted, and for each stream a second descriptor into which a number of layers indicating the total number of hierarchies of the stream is inserted and for each layer a level specification value (sublayer_level_idc) is inserted. an image encoding unit adapted to perform hierarchical encoding on image data of pictures constituting moving image data and to generate a first video stream including the encoded image data of the pictures on a low hierarchy side and a second video stream including the encoded image data of the pictures on a high hierarchy side, the encoded image data having a network abstraction layer, NAL, unit structure, a level specification value of the first video stream being inserted into a NAL unit of a sequence parameter set, SPS, of the first video stream; and a transmission unit adapted to transmit a transport stream including the first video stream and the second video stream generated in the image encoding unit, stream identification information as a degree-of-priority information that is set to be higher for a hierarchy group on a low hierarchy side and indicating a hierarchy group to which the encoded image data of each picture included in each video stream belongs, and for each stream a first descriptor into which the level specification value of the video stream is inserted, and for each stream a second descriptor into which a number of layers indicating the total number of hierarchies of the stream is inserted and for each layer a level specification value (sublayer_level_idc) is inserted. the first video stream and the second video stream generated in the image encoding unit, stream identification information as a degree-of-priority information that is set to be higher for a hierarchy group on a low hierarchy side and indicating a hierarchy group to which the encoded image data of each picture included in each video stream belongs, and for each stream a first descriptor into which the level specification value of the video stream is inserted, and for each stream a second descriptor into which a number of layers indicating the total number of hierarchies of the stream is inserted and for each layer a level specification value (sublayer_level_idc) is inserted.