Transmission device, transmission method, reception device, and reception method using hierarchical encoding to allow decoding based on device capability
An image data of pictures constituting moving image data is encoded to generate an encoded video stream. In this case, the image data of the pictures constituting the moving image data is classified into a plurality of levels and encoded to generate a video stream having the image data of the pictures at the respective levels. Hierarchical composition is equalized between a low-level side and a high-level side, and corresponding pictures on the low-level side and the high-level side are combined into one set and are sequentially encoded. This allows a reception side to decode the encoded image data of the pictures on the low-level side and the high-level side with a smaller buffer size and a reduced decoding delay.
1. A transmission device comprising:
circuitry configured to
perform hierarchical encoding on image data of pictures constituting moving image data to generate a video stream having encoded image data on a low-level side and a high-level side, and
insert a level specified value of the encoded image data on the low-level side and a level specified value of the video stream into a layer of the video stream,
multiplex the generated video stream to obtain a container including one or more video streams,
insert hierarchical information including the level specified value of the encoded image data on the low-level side and the level specified value of the video stream into a table of the container, the table describing the one or more video streams included in the container; and
transmit the container comprising (i) the table describing the one or more video streams and including the hierarchical information and (ii) the generated video stream having the layer including the level specified value of the encoded image data on the low-level side and the level specified value of the video stream.
2. The transmission device according to claim 1 , wherein the circuitry is configured to combine and sequentially encode the image data on the low-level side and the high-level side.
3. The transmission device according to claim 1 , wherein
the encoded image data has a network abstraction layer (NAL) unit structure, and
the circuitry is configured to insert the level specified value of the encoded image data on the low-level side together with the level specified value of the video stream into a sequence parameter set (SPS) NAL unit of the video stream.
4. The transmission device according to claim 1 , wherein the hierarchical information further includes maximum and minimum information on levels of the encoded image data contained in the video stream.
5. The transmission device according to claim 1 , wherein flag information indicative of insertion of the level specified value of the encoded image data on the low-level side is further inserted into the layer of the video stream.
6. A transmission method comprising:
performing hierarchical encoding on image data of pictures constituting moving image data to generate a video stream having encoded image data on a low-level side and a high-level side;
inserting a level specified value of the encoded image data on the low-level side and a level specified value of the video stream into a layer of the video stream; and
multiplexing the video stream to obtain a container including one or more video streams;
inserting hierarchical information including the level specified value of the encoded image data on the low-level side and the level specified value of the video stream into a table of the container, the table describing the one or more video streams included in the container; and
transmitting the container comprising (i) the table describing the one or more video streams and including the hierarchical information and (ii) the generated video stream having the layer including the level specified value of the encoded image data on the low-level side and the level specified value of the video stream.
7. A reception device comprising:
circuitry configured to
receive a container containing:
a video stream having encoded image data on a low-level side and a high-level side generated by performing hierarchical encoding on image data of pictures constituting moving image data, and
a table describing one or more video streams included in the container, the table including hierarchical information including a level specified value of the encoded image data on the low-level side and a level specified value of the video stream, wherein
the level specified value of the encoded image data on the low-level side and the level specified value of the video stream are inserted into a layer of the video stream; and
decode the encoded image data on the low-level side or the encoded image data on both the low-level side and the high-level side contained in the received container depending on a decoding capability to obtain the image data of the pictures constituting the moving image data.
8. The reception device according to claim 7 , wherein the circuitry is configured to retrieve the encoded image data on the low-level side or the encoded image data on both the low-level side and the high-level side from the video stream depending on the decoding capability based on the hierarchical information.
9. The reception device according to claim 7 , wherein the circuitry is configured to match a frame rate of the obtained image data with a display capability.
10. The reception device according to claim 9 , wherein the circuitry is configured to subject the obtained image data to interpolation or sub sampling to match the frame rate with the display capability.
11. The reception device according to claim 7 , wherein the container is in MPEG-4 Part 14 (MP4) format.
12. A reception method comprising:
receiving a container containing
a video stream having encoded image data on a low-level side and a high-level side generated by performing hierarchical encoding on image data of pictures constituting moving image data, and
a table describing one or more video streams included in the container, the table including hierarchical information including a level specified value of the encoded image data on the low-level side and a level specified value of the video stream, wherein
the level specified value of the encoded image data on the low-level side and the level specified value of the video stream are inserted into a layer of the video stream; and
decoding the encoded image data on the low-level side or the encoded image data on both the low-level side and the high-level side contained in the received container depending on a decoding capability to obtain the image data of the pictures constituting the moving image data.
13. The reception method according to claim 12 , further comprising retrieving the encoded image data on the low-level side or the encoded image data on both the low-level side and the high-level side from the video stream depending on the decoding capability based on the hierarchical information.
14. The reception method according to claim 12 , further comprising matching a frame rate of the obtained image data with a display capability.
15. The reception method according to claim 14 , further comprising subjecting the obtained image data to interpolation or sub sampling to match the frame rate with the display capability.
16. The reception method according to claim 12 , wherein the container is in MPEG-4 Part 14 (MP4) format.