Transmission device, transmission method, reception device, and reception method

A transmission method comprising:

• an image coding step of, by an image coding unit, encoding image data of each picture of a base layer to generate a first coded stream, and encoding image data of each picture of an enhancement layer to generate a second coded stream;
• and
• a transmission step of, by a transmission unit, transmitting a container including the first coded stream and the second coded stream, wherein,
• in the image coding step,
• a picture of the base layer is able to be used as a reference picture in encoding the image data of each picture of the enhancement layer, and
• conversion processing for causing the image data of the base layer to correspond to the image data of the enhancement layer is applied to a block of the reference picture to perform motion compensation prediction coding processing when the picture of the base layer is used as the reference picture.

A reception device comprising:

• a reception unit configured to receive a container including a first coded stream obtained by encoding image data of each picture of a base layer and a second coded stream obtained by encoding image data of each picture of an enhancement layer, wherein
• a picture of the base layer is able to be used as a reference picture in encoding the image data of each picture of the enhancement layer, and conversion processing for causing the image data of the base layer to correspond to the image data of the enhancement layer is applied to a block of the reference picture to perform motion compensation prediction coding processing when the picture of the base layer is used as the reference picture, and
• the reception device further comprises
• a processing unit configured to process the first coded stream, or the first coded stream and the second coded stream, according to display capability, to obtain display image data.

A reception method comprising:

• a reception step of, by a reception unit, receiving a container including a first coded stream obtained by encoding image data of each picture of a base layer and a second coded stream obtained by encoding image data of each picture of an enhancement layer, wherein
• a picture of the base layer is able to be used as a reference picture in encoding the image data of each picture of the enhancement layer, and conversion processing for causing the image data of the base layer to correspond to the image data of the enhancement layer is applied to a block of the reference picture to perform motion compensation prediction coding processing when the picture of the base layer is used as the reference picture, and
• the reception method further comprises
• a processing step of, by a processing unit, processing the first coded stream, or the first coded stream and the second coded stream, according to display capability, to obtain display image data.