he value of seq_parameter_set_id shall be in the range of 0 to 31, inclusive. NOTE 2 - When the sequence parameter set identified by parameter set id is not already active, the buffering SEI message will activate the identified sequence parameter set for the current coded video sequence as specified in clause 7.4.1.2.1. initial_cpb_removal_delay[ SchedSelIdx ] specifies the delay for the SchedSelIdx-th CPB between the time of arrival in the CPB of the first bit of the coded data associated with the access unit associated with the buffering period SEI message and the time of removal from the CPB of the coded data associated with the same access unit, for the first buffering period after HRD initialisation. The syntax element has a length in bits given by nitial_cpb_removal_delay_length_minus1+ 1. It is in units of a 90 kHz clock. hitial_cpb_removal_delay[SchedSelldx ] shall not be equal to 0 and shall not exceed 90000 * CpbSize[ SchedSelldx BitRate[ SchedSelldx the time-equivalent of the CPB size in 90 kHz clock units. nitial_cpb_removal_delay_offset[ SchedSelIdx ] is used for the SchedSelIdx-th CPB in combination with the pb_removal_delay to specify the initial delivery time of coded access units to the CPB. initial_cpb_removal_delay_offset| SchedSelIdx is in units of clock. initial_cpb_removal_delay_offset[ SchedSelIdx ] syntax element is a fixed length code having a length in bits given by initial_cpb_removal_delay_length_minus1+1.This syntax element is not used by decoders and is needed only for the delivery scheduler (HSS) specified in Annex C. Over the entire coded video sequence, the sum of nitial_cpb_removal_delay[SchedSelldx nitial_cpb_removal_delay_offset[SchedSelle shall be constant for each value of SchedSelIdx. D.2.2 Picture timing SEI message semantics NOTE 1 - The syntax of the picture timing SEI message is dependent on the content of the sequence parameter set that is active for the primary coded picture associated with the picture timing SEI message. However, unless the picture timing SEI message 