 in an MVC scalable nesting SEI message, the semantics for sub_seq_layer_num of the sub-sequence information SEI message is modified as follows: sub_seq_layer_num specifies the sub-sequence layer number of the current picture. When the current picture resides in a sub-sequence for which the first picture in decoding order is an IDR picture, the value of sub_seq_layer_num shall be equal to 0. For a non-paired reference field, the value of sub_seq_layer_num : shall be equal to 0. sub_seq_layer_num shall be in the range of 0 to 255, inclusive. Otherwise, if payloadType is equal to 0 or 1, the following applies: If the SEI message is not included in an MVC scalable nesting SEI message, the following applies. When the SEI message and all other SEI messages with payloadType equal to 0 or 1 not included in an MVC scalable nesting SEI message are used as the buffering period and picture timing SEI messages for checking the bitstream conformance according to Annex C and the decoding process specified in clauses 2-9 is used, the bitstream shall be conforming to this Recommendation | International Standard. Otherwise (the SEI message is included in an MVC scalable nesting SEI message), the following applies. When the SEI message and all other SEI messages with payloadType equal to 0 or 1 included in an MVC scalable nesting SEI message with identical values of sei_op_temporal_io and sei_op_view_id[i for all i in Rec. ITU-T H.264 (01/2012) the range of 0 to num_view_components_op_minus1 inclusive, are used as the buffering period and picture timing SEI messages for checking the bitstream conformance according to Annex C, the bitstream that would be obtained by invoking the bitstream extraction process as specified in clause H.8.3 with tIdTarget equal to sei_op_temporal_id and viewIdTargetList equal to sei_op_view_id[i for all i in the range of 0 to num_view_components_op_minus1, inclusive, shall be conforming to this Recommendation International Standard. In the semantics of clauses D.2.1 and D.2.2, the syntax elements num_un