 to P_8x8, P_8x8ref0, or B_8x8, depending on the sub-macroblock type. 1 macroblock partition of 2 macroblock partitions of 2 macroblock partitions of 4 sub-macroblocks of 16*16 luma samples and 16*8 luma samples and 8*16 luma samples and 8*8 luma samples and associated chroma samples associated chroma samples associated chroma samples associated chroma samples Macroblock partitions 1 sub-macroblock partition 2 sub-macroblock partitions 2 sub-macroblock partitions 4 sub-macroblock partitions of 8*8 luma samples and of 8*4 luma samples and of 4*8 luma samples and of 4*4 luma samples and associated chroma samples associated chroma samples associated chroma samples associated chroma samples Sub-macroblock partitions H.264(09)_F6-9 Figure 6-9 - Macroblock partitions, sub-macroblock partitions, macroblock partition scans, and sub-macroblock partition scans 6.4.2.1 Inverse macroblock partition scanning process Input to this process is the index of a macroblock partition mbPartIdx. Output of this process is the location ( X, y ) of the upper-left luma sample for the macroblock partition mbPartIdx relative to the upper-left sample of the macroblock. The inverse macroblock partition scanning process is specified by X = InverseRasterScan( mbPartIdx, MbPartWidth(mb_type), MbPartHeight(mb_type), 16, 0) (6-11) y = InverseRasterScan( mbPartIdx,MbPartWidth(mb_type),MbPartHeight(mb_type),16,1 (6-12) Rec. ITU-T H.264 (01/2012) 6.4.2.2 Inverse sub-macroblock partition scanning process Inputs to this process are the index of a macroblock partition mbPartIdx and the index of a sub-macroblock partition subMbPartIdx. Output of this process is the location (x,y) of the upper-left luma sample for the sub-macroblock partition subMbPartIdx relative to the upper-left sample of the sub-macroblock. The inverse sub-macroblock partition scanning process is specified as follows: If mb_type is equal to P_8x8, P_8x8ref0, or B_8x8, X = InverseRasterScan( subMbPartIdx, ,SubMbPartWidth(sub_mb_type[mbPartIdx]), SubMbPartHeight(sub_mb_type[mbPartIdx]),