is assigned to mbAddrA\mbPartIdxA and mbAddrB\mbPartIdxB. Rec. ITU-T H.264 (01/2012) With ref_idx_IX[ mbPartIdxN ] (with N being either A or B) specifying the syntax element for the macroblock mbAddrN, let the variable refIdxZeroFlagN be derived as follows: If MbaffFrameFlag is equal to 1, the current macroblock is a frame macroblock, and the macroblock mbAddrN is a field macroblock, refIdxZeroFlagN=((ref_idx_lX[mbPartIdxN]>1)?0:1 (9-12) Otherwise, refIdxZeroFlagN=((ref_idx_IX[mbPartIdxN]>0)?0:1) = (9-13) Let the variable predModeEqualFlagN be specified as follows: If mb_type for the macroblock mbAddrN is equal to B_Direct_16x16 or B_Skip, predModeEqualFlagN is set equal to 0. Otherwise, if the macroblock mbAddrN has mb_type equal to P_8x8 or B_8x8, the following applies: If SubMbPredMode(sub_mb_type[mbPartIdxN]) is not equal to Pred LX and not equal to BiPred, predModeEqualFlagN is set equal to 0, where sub_mb_type specifies the syntax element list for the macroblock mbAddrN. Otherwise, predModeEqualFlagN is set equal to 1. Otherwise, the following applies: IfMbPartPredMode(mb_type,mbPartIdxN) is not equal to Pred LX and not equal to BiPred, predModeEqualFlagN is set equal to 0, where mb_type specifies the syntax element for the macroblock mbAddrN. Otherwise, predModeEqualFlagN is set equal to 1. Let the variable condTermFlagN (with N being either A or B) be derived as follows: If any of the following conditions are true, condTermFlagN is set equal to 0: mbAddrN is not available, the macroblock mbAddrN has mb_type equal to P_Skip or B_Skip, the macroblock mbAddrN is coded in an Intra macroblock prediction mode, predModeEqualFlagN is equal to 0, refIdxZeroFlagN is equal to 1. Otherwise, condTermFlagN is set equal to 1. The variable ctxIdxInc is derived as ctxIdxInc = condTermFlagA + 2* condTermFlagB (9-14) 9.3.3.1.1.7 Derivation process of ctxIdxInc for the syntax elements mvd_10 and mvd_l1 Inputs to this process are mbPartIdx, subMbPartIdx, and ctxIdxOffset. Output of this process is ctxIdxInc. The interpretatio