r set RBSP becomes the active SVC sequence parameter set RBSP. 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 SVC sequence parameter set RBSP and it is referred to by activation of a picture parameter set RBSP (using that value of q_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 DQId equal to DQIdMax (the picture parameter set RBSP becomes the active picture parameter set RBSP) and the access unit does not contain an activating buffering period SEI message, the subset sequence parameter set RBSP is activated. This subset sequence parameter set RBSP is called the active SVC sequence parameter set RBSP until it is deactivated when another SVC sequence parameter set RBSP becomes the active SVC sequence parameter set RBSP. A subset 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 _parameter_se id is not already the active SVC sequence parameter set RBSP and it is referred to by an activating buffering period SEI message (using that value of seq_parameter_set_id) that is included in a scalable nesting SEI message, the subset sequence parameter set RBSP is activated. This subset sequence parameter set RBSP, is called the active SVC sequence parameter set RBSP until it is deactivated when another SVC sequence parameter set RBSP becomes the active SVC sequence parameter set RBSP. A subset sequence parameter set RBSP, with that particular value of seq_parameter_set_id, shall be available to the decoding process prior to its activation. NOTE 3 - The active SVC sequence parameter 