Signaling change in output layer sets
A system for decoding a video bitstream includes receiving a bitstream and a plurality of enhancement bitstreams together with receiving a video parameter set and a video parameter set extension. The system also receives an output layer set change message including information indicating a change in at least one output layer set.
1. A method for decoding a video bitstream, the method comprising:
(a) receiving a set of picture timing parameters including a coded picture buffer removal delay parameter for removing an access unit from a coded picture buffer on an access unit level;
(b) receiving data representative of a coded video image;
(c) storing the data in the coded picture buffer;
(d) determining whether the access unit is to be removed from the coded picture buffer for decoding on the access unit level or a decoding unit is to be removed from the coded picture buffer for decoding on a sub-picture level;
(e) when the decoding unit is to be removed from the coded picture buffer for decoding on the sub-picture level:
(i) receiving a flag indicating whether the bitstream includes a parameter representing a common removal delay for all decoding units in an access unit,
(ii) if the flag indicates that the parameter representing a common removal delay for all decoding units is in the bitstream, receiving the parameter representing the common removal delay for all decoding units where the common removal delay is a duration between a removal time of a current decoding unit from the coded picture buffer and a removal time of an immediately preceding decoding unit from the coded picture buffer,
(iii) if the flag indicates that the parameter representing a common removal delay for all decoding units is not in the bitstream, receiving separate decoding unit delay parameters each representing a delay between consecutive decoding units in the access unit,
(iv) removing the decoding unit from the coded picture buffer based on the parameter representing either the common removal delay or the separate decoding unit delay parameters, and
(v) decoding the removed decoding unit; and
(f) when the access unit is to be removed from the coded picture buffer for decoding on the access unit level:
(i) determining an access unit removal delay for the access unit in the data,
(ii) removing the access unit from the coded picture buffer based on the access unit delay, and
(iii) decoding the removed access unit,
wherein
the decoding unit is a subset of the access unit, and
the value of a clock tick, t c , multiplied by the coded picture buffer removal delay parameter for removing the access unit from the coded picture buffer on the access unit level is equal to the value of a sub-picture clock tick, t c,sub , multiplied by the sum of all separate decoding unit delay parameters in the access unit, where the access unit removal delay is represented in number of clock ticks, and the decoding unit delay parameters are represented in numbers of sub-picture clock ticks.