 is deactivated when another SVC sequence parameter set RBSP becomes the active layer SVC sequence parameter set RBSP for DQId equal to 0 or when decoding an access unit with DQIdMax equal to 0. A sequence parameter set RBSP, with that particular value of seq_parameter_set_id, shall be available to the decoding process prior to its activation. When a sequence parameter set RBSP (nal_unit_type is equal to 7) with a particular value of q_parameter_s id is not already the active layer SVC sequence parameter set RBSP for DQId equal to 0 and it is referred to by an activating layer buffering period SEI message for DQId equal to 0 (using that value of seq_parameter_set_id) that is not included in a scalable nesting SEI message and DQIdMax is greater than 0, the sequence parameter set RBSP is activated for layer representations with DQId equal to 0. This sequence parameter set RBSP is called the active layer SVC sequence parameter set RBSP for DQId equal to 0 until it is deactivated when another SVC sequence parameter set RBSP becomes the active layer SVC sequence parameter set RBSP for DQId equal to 0 or when decoding an access unit with DQIdMax equal to 0. A sequence parameter set RBSP, with that particular value of seq_parameter_set_id, shall be available to the decoding process prior to its activation. When a subset sequence parameter set RBSP (nal_unit_type is equal to 15) with a particular value of seq_parameter_set_id is not already the active layer SVC sequence parameter set RBSP for a particular value of DQId less than DQIdMax and it is referred to by activation of a picture parameter set RBSP (using that value of seq_parameter_set_id) and the picture parameter set RBSP is activated by a coded slice in scalable extension NAL unit (nal_unit_type is equal to 20) with the particular value of DQId (the picture parameter set RBSP becomes the active layer picture parameter set RBSP for the particular value of DQId) and the access unit does not contain an activating layer buffering period SEI message for the particula