SizeInMbs)x4 arrays refIdxL0 and refldxL1 specifying reference indices for the macroblocks of the current layer representation, two (PicSizeInMbs)x4x4x2 arrays mvL0 and mvL1 specifying motion vector components for the macroblocks of the current layer representation. Outputs of this process are: the reference index predictors refIdxPredL0 and refIdxPredL1, the motion vector predictors mvPredL0 and mvPredL1, the variable myCntInc. The variable currSubMbType is derived as follows: If mbType[ CurrMbAddr ] is equal to B_Skip or B_Direct_16x16, currSubMbType is marked as "unspecified". Otherwise (mbType[ CurrMbAddr ] is equal to B 8x8 and subMbType[ CurrMbAddr ][ mbPartIdx ] is equal to B_Direct_8x8), currSubMbType is set equal to B_Bi_8x8. NOTE - The variable currSubMbType is only used for deriving the variable predPartWidth in clause 6.4.11.7, which specifies the partition width of the current macroblock or sub-macroblock partition for determining neighbouring partitions that are used for motion vector prediction. Inside clause 6.4.11.7, the variable predPartWidth is set equal to 16 when the current macroblock is coded with macroblock type equal to B_Skip or B_Direct_16x16 or the current sub-macroblock is coded with sub macroblock type equal B_Direct_8x8. When the current clause is invoked for a sub-macroblock coded with sub-macroblock type equal to B Direct 8x8 (the current clause is only invoked for NAL units with nal_unit_type equal to 20), currSubMbType is set equal to B_Bi_8x8 in order to set the variable predPartWidth equal to 8 in clause 6.4.11.7. For X being replaced by 0 and 1, the reference index predictor refIdxPredLX is derived by applying the following ordered steps: The derivation process for motion data of neighbouring partitions as specified in clause 8.4.1.3.2 is invoked with mbPartIdx, subMbPartIdx set equal to 0, currSubMbType, and listSuffixFlag set equal to X as the inputs and the outputs are the reference indices refIdxLXN with N being replaced by A, B, and C. For this invocation of the process 