dL0 and the reference index predictor refIdxPredL0. For this invocation of the process in clause 8.4.1.1, the modifications specified above in items a) through of this clause apply. Otherwise, if isDirectFlag is equal to 1 and DQId is equal to 0 (nal_unit_type is not equal to 20), the derivation process for spatial direct luma motion vector and reference index prediction mode as specified in clause 8.4.1.2.2 is invoked with mbPartIdx and subMbPartIdx as the inputs and the output variables refIdxL0, refIdxL1, mvL0, mvL1, and subMvCnt are assigned to the reference index predictors refIdxPredL0 and refIdxPredL1, the motion vectors predictors mvPredL0 and mvPredL1, and the variable mvCntInc, respectively. For this invocation of the process in clause 8.4.1.2.2, the modifications specified above in items a) through s) of this clause apply. NOTE - When the current clause is invoked, direct_spatial_mv_pred_flag is always equal to 1. Otherwise, if isDirectFlag is equal to 1 (and DQId is greater than 0 and nal_unit_type is equal to 20), the SVC derivation process for luma motion vectors and reference indices for B_Skip, 3_Direct_16x16, and Direct in NAL units with nal_unit_type equal to 20 as specified in clause G.8.4.1.2 is invoked with mbPartIdx, fieldMbFlag, mbType, subMbType, predFlagL0, predFlagL1, refIdxL0, refIdxL1, mvL0, and mvL1 as the inputs and the outputs are refIdxPredL0, refIdxPredL1, mvPredL0, mvPredL1, and myCntInc. Otherwise, the variable mvCntInc is initially set equal to 0, and for X being replaced by 0 and 1, the following applies: Rec. ITU-T H.264 (01/2012) If any of the following conditions are true, refIdxPredLX is set equal to -1 and both components of mvPredLX are set equal to 0: mbType[ CurrMbAddr ] is not equal to P_8x8, P_8x8ref0, or B_8x8 and MbPartPredMode( mbType[ CurrMbAddr ], mbPartIdx ) is not equal to Pred LX or BiPred, mbType[ CurrMbAddr is equal to P_8x8, P_8x8ref0, or B 8x8 SubMbPartPredMode( subMbType[ CurrMbAddr ][ mbPartIdx ]) is not equal to Pred_LX or BiPred. Otherwise, if base_mo