Encoder, decoder, encoding method, and decoding method

A decoder comprising:

• memory;
• and
• circuitry coupled to the memory and configured to:
• decode, for each of temporal sub-layers for temporal scalability different from spatial scalability, first parameters from buffering period supplemental enhancement information (SEI), the first parameters presenting initial delays in timing to extract data from a coded picture buffer (CPB);
• and
• decode a second parameter from the buffering period SEI, the second parameter indicating a total number of the temporal sub-layers, wherein
• a value of the second parameter is equal to a value of a third parameter that is decoded from a sequence parameter set and indicates a total number of the temporal sub-layers.

A non-transitory computer readable medium storing a bitstream, the bitstream comprising:

• buffering period supplemental enhancement information (SET);
• and a sequence parameter set (SPS), the buffering period SEI and the SPS causing a decoder to perform temporal scalability decoding on pictures,
• the buffering period SEI including:
• first parameters for each of temporal sub-layers for the temporal scalability decoding different from spatial scalability decoding, the first parameters presenting initial delays in timing to extract data from a coded picture buffer (CPB);
• and
• a second parameter indicating a total number of the temporal sub-layers,
• the SPS including a third parameter indicating a total number of the temporal sub-layers, a value of the third parameter is equal to a value of the second parameter.