l be inferred to be B_Skip and the macroblock type is collectively referred to as B macroblock type. mb_skip_flag equal to 0 specifies that the current macroblock is not skipped. mb_field_decoding_flag equal to 0 specifies that the current macroblock pair is a frame macroblock pair. mb_field_decoding_flag equal to 1 specifies that the macroblock pair is a field macroblock pair. Both macroblocks of a Rec. ITU-T H.264 (01/2012) frame macroblock pair are referred to in the text as frame macroblocks, whereas both macroblocks of a field macroblock pair are referred to in the text as field macroblocks. When MbaffFrameFlag is equal to 0 (mb_field_decoding_flag is not present), mb_field_decoding_flag is inferred to be equal to field_pic_flag. When MbaffFrameFlag is equal to 1 and mb_field_decoding_flag is not present for both the top and the bottom macroblock of a macroblock pair, the value of mb_field_decoding_flag shall be inferred as follows: If there is a neighbouring macroblock pair immediately to the left of the current macroblock pair in the same slice, the value of mb_field_decoding_flag is inferred to be equal to the value of mb_field_decoding_flag for the neighbouring macroblock pair immediately to the left of the current macroblock pair, Otherwise, if there is no neighbouring macroblock pair immediately to the left of the current macroblock pair in the same slice and there is a neighbouring macroblock pair immediately above the current macroblock pair in the same slice, the value of mb_field_decoding_flag is inferred to be equal to the value of mb_field_decoding_flag for the neighbouring macroblock pair immediately above the current macroblock pair, Otherwise (there is no neighbouring macroblock pair either immediately to the left or immediately above the current macroblock pair in the same slice), the value of mb_field_decoding_fla is inferred to be equal to 0. NOTE - When MbaffFrameFlag is equal to 1 and mb_field_decoding_flag is not present for the top macroblock of a macroblock pair (because the top macrob