mFieldOrderCnt, a BottomFieldOrderCnt that has a value equal to a TopFieldOrderCnt unless the BottomFieldOrderCnt and TopFieldOrderCnt belong to the same coded frame or complementary field pair. The bitstream shall not contain data that result in values of TopFieldOrderCnt, BottomFieldOrderCnt, PicOrderCntMsb, or FrameNumOffset used in the decoding process as specified in clauses 8.2.1.1 to 8.2.1.3 that exceed the range of values from -231 to 231 - 1, inclusive. The function PicOrderCnt( picX) ) is specified as follows: if( picX is a frame or a complementary field pair) PicOrderCnt( picX) = Min( TopFieldOrderCnt, BottomFieldOrderCnt of the frame or complementary field pair picX else if( picX is a top field PicOrderCnt( picX ) = TopFieldOrderCnt of field picX (8-1) else if( picX is a bottom field) PicOrderCnt( picX ) = BottomFieldOrderCnt of field picX Then DiffPicOrderCnt( picA, picB ) is specified as follows: DiffPicOrderCnt( picA, picB = PicOrderCnt( picA - PicOrderCnt(picB) (8-2) The bitstream shall not contain data that result in values of DiffPicOrderCnt( picA, picB) ) used in the decoding process that exceed the range of -215 to 215 - 1, inclusive. NOTE 2 - Let X be the current picture and Y and Z be two other pictures in the same sequence, Y and Z are considered to be in the same output order direction from X when both DiffPicOrderCnt( X, Y ) and DiffPicOrderCnt( X, Z) are positive or both are negative. NOTE 3 - Many encoders assign TopFieldOrderCnt and BottomFieldOrderCnt proportional to the sampling time of the corresponding field (which is either a coded field or a field of a coded frame) relative to the sampling time of the first output field of the previous IDR picture or the previous reference picture (in decoding order) that includes a memory_management_control_operation equal to 5. When the current picture includes a memory_management_control_operation equal to 5, PicOrderCnt( CurrPic ) shall be greater than PicOrderCnt( any other picture in listD ). 8.2.1.1 Decoding process for picture order count