 of the target picture. spare_field_flag equal to 0 indicates that the target picture and the spare pictures are decoded frames. spare_field_flag equal to 1 indicates that the target picture and the spare pictures are decoded fields. Rec. ITU-T H.264 (01/2012) target_bottom_field_flag equal to 0 indicates that the target picture is a top field. arget_bottom_field_flag equal to 1 indicates that the target picture is a bottom field. A target picture is a decoded reference picture for which the corresponding primary coded picture precedes the current picture, in decoding order, and in which the values of frame_num, field_pic_flag (when present) and bottom_field_flag (when present) are equal to target_frame_num,spare_field_flag and target_bottom_field_flag, respectively. num_spare_pics_minus1 indicates the number of spare pictures for the specified target picture. The number of spare pictures is equal to num_spare_pics_minusl The value of num_spare_pics_minusl shall be in the range of 0 to 15, inclusive. delta_spare_frame_num[ i ] is used to identify the spare picture that contains the i-th set of spare slice group map units, hereafter called the i-th spare picture, as specified below. The value of delta_spare_frame_num[ i ] shall be in the range of 0 to MaxFrameNum - -2 + spare_field_flag, inclusive. The frame num of the i-th spare picture, spareFrameNum[ is derived as follows for all values of i from 0 to num_spare_pics_minus1, inclusive: candidateSpareFrameNum = target_frame_num spare_field_flag for i<=num_spare_pics_minus1;i++) { candidateSpareFrameNum candidateSpareFrameNum=MaxFrameNum - 1 spareFrameNum[ ]=candidateSpareFrameNum-delta_spare_frame_num[i - (D-3) if( spareFrameNum[ spareFrameNum[ MaxFrameNum+spareFrameNum[i] candidateSpareFrameNum = spareFrameNum[i 1 spare_field_flag spare_bottom_field_flag| ] equal to 0 indicates that the i-th spare picture is a top field. spare_bottom_field_flag[i equal to 1 indicates that the i-th spare picture is a bottom field. The 0-th spare picture is a decoded reference pic