Transmitting method of transmitting hierarchically encoded data

1. A transmitting method for transmitting encoded data items obtained by chronologically and hierarchically encoding a video image, the encoded data items being encoded in an encoding order and to be displayed in a display order different from the encoding order, the transmitting method comprising:

generating a plurality of first packets and a second packet,

the plurality of first packets being obtained by packetizing the encoded data items differently according to whether a layer level of a corresponding one of the encoded data items is a base layer level or an enhancement layer level, the plurality of first packets each being allocated with a packet ID, each of the packet IDs being a numeral,

the second packet including information indicating an association relationship between assets and the packet IDs; and

transmitting an encoded stream and the second packet, the encoded stream including the plurality of first packets,

wherein the numerical value of a packet ID allocated to each of one or more first packets corresponding to the base layer level is identical to the numerical value of a packet ID allocated to each of one or more first packets corresponding to the enhancement layer level.

2. The transmitting method according to claim 1 , wherein

an encoded data item of the base layer level is independently decodable or is decodable with reference to a decoded data item of another encoded data item of the base layer level among the encoded data items, and

an encoded data item of the enhancement layer level is decodable with reference to a decoded data item of an encoded data item of the base layer level among the encoded data items.

3. The transmitting method according to claim 2 , wherein

in the generating, the encoded stream includes a first encoded stream and a second encoded stream,

the first encoded stream includes the one or more first packets corresponding to the base layer level and not including the one or more first packets corresponding to the enhancement layer level,

the second encoded stream includes the one or more first packets corresponding to the enhancement layer level and not including one or more first packets corresponding to the base layer level, and

the transmitting includes transmitting the first encoded stream via a first channel, and transmitting the second encoded stream via a second channel different from the first channel.

4. The transmitting method according to claim 3 , wherein

the generating includes generating the first encoded stream and the second encoded stream according to different multiplexing methods.

5. The transmitting method according to claim 4 , wherein the generating includes:

generating one of the first encoded stream and the second encoded stream according to MPEG-2 TS (Moving Picture Experts Group-2 Transport Stream); and

generating the other one of the first encoded stream and the second encoded stream according to MMT (MPEG Media Transport).

6. A transmitting method, performed by a transmission device, comprising:

obtaining pictures generated by hierarchy encoding a video, the pictures including first pictures and second pictures belonging to a basic layer and an extended layer, respectively, decode order of the pictures being different from display order of the pictures;

encapsulating the first pictures and the second pictures in first packets and second packets, respectively;

associating a first packet identifier and a second packet identifier with the first packets and the second packets, respectively;

generating a third packet to include information indicating the association of the first packet identifier and the second packet identifier with the first packets and the second packets;

associating a third packet identifier with the third packet; and

transmitting the first packets, the second packets, and the third packet,

wherein the first packet identifier, the second packet identifier, and the third packet identifier are included in packet identifiers to identify respective assets, each of the first packet identifier, the second packet identifier, and the third packet identifier being a numeral, and

the numerical value of the first packet identifier is identical to the numerical value of the second packet identifier.

7. The transmitting method according to claim 6 , wherein

the assets correspond to respective data entities, and

the data entities each have same transport characteristics.

8. The transmitting method according to claim 6 , wherein the packet identifiers include a fourth packet identifier to identify an audio data entity included in the assets.

9. A receiving method, performed by a reception device, comprising:

receiving packets;

reading packet identifiers of the packets to identify a third packet among the packets, the third packet being associated with a third packet identifier;

reading information included in the third packet, the information indicating association of a first packet identifier and a second packet identifier with first packets and second packets; and

extracting first pictures and second pictures from the first packets and the second packets, respectively, the first pictures and the second pictures being included in pictures generated by hierarchy encoding a video, the first pictures and the second pictures belonging to a basic layer and an extended layer, respectively, wherein

decoding order of the pictures is different from display order of the pictures,

the first packet identifier, the second packet identifier, and the third packet identifier are included in packet identifiers to identify respective assets, each of the first packet identifier, the second packet identifier, and the third packet identifier being a numeral, and

the numerical value of the first packet identifier is identical to the numerical value of the second packet identifier.