 B_Direct_8x8 in clause 8.4.1.2 shall use temporal direct mode prediction as specified in clause 8.4.1.2.3. num_ref_idx_active_override_flag equal to 1 specifies that the syntax element num_ref_idx 10active_minus1 is present for P, SP, and B slices and that the syntax element aum_ref idx 1_active_minus1 is present for B slices. aum_ref_idx_active_override_flag equal to 0 specifies that the syntax elements num_ref idx 10_active_minus and um_ref idx l1_active_minus1 are not present. When the current slice is a P, SP, or B slice and field_pic_flag is equal to 0 and the value of aum_ref_idx_10_default_active_minus1 in the picture parameter set exceeds 15,num_ref_idx_active_override_flagshall be equal to 1. When the current slice is a B slice and field_pic_flag is equal to 0 and the value of num_ref_idx_l1_default_active_minus1 in the picture parameter set exceeds 15, num_ref_idx_active_override_flag shall be equal to 1. num_ref_idx_10_active_minus1 specifies the maximum reference index for reference picture list 0 that shall be used to decode the slice. When the current slice is a P, SP, or B slice and numref idx 10 active minus1 is not present, num_ref_idx_10_active_minus1 shall be inferred to be equal to num_ref_idx_10_default_active_minus1. The range of num_ref_idx_10_active_minus1 is specified as follows: If field_pic_flag is equal to 0, num_ref_idx_10_active_minus] shall be in the range of 0 to 15, inclusive. When MbaffFrameFlag is equal to 1, num_ref idx 10_active_minus1 is the maximum index value for the decoding of frame macroblocks and 2 * num ref idx 10active minus1 + 1 is the maximum index value for the decoding of field macroblocks. - Otherwise (field_pic_flag is equal to 1), num ref idx 10active minusls shall be in the range of 0 to 31, inclusive. num_ref_idx_l1_active_minus1 specifies the maximum reference index for reference picture list 1 that shall be used to decode the slice. When the current slice is a B slice and num ref idx 1 active minu is not present, num_ref idx 1_active minusl shall be inferr