CodedBlockPatternLuma = coded_block_pattern % 16 CodedBlockPatternChroma = coded_block_pattern/1 16 (7-35) When the macroblock type is not equal to P_Skip, B_Skip, or I_PCM, the following applies: If the macroblock prediction mode is equal Intra_16x16, the following applies: If ChromaArrayType is not equal to 3, the value of CodedBlockPatternLuma specifies the following. If CodedBlockPatternLuma is equal to 0, all AC transform coefficient levels of the luma component of the macroblock are equal to 0 for all 16 of the 4x4 blocks in the 16x16 luma block. Otherwise (CodedBlockPatternLuma is not equal to 0), CodedBlockPatternLuma is equal to 15, at least one of the AC transform coefficient levels of the luma component of the macroblock shall be non-zero, and the AC transform coefficient levels are scanned for all 16 of the 4x4 blocks in the 16x16 block. Rec. ITU-T H.264 (01/2012) Otherwise (ChromaArrayType is equal to 3), the value of CodedBlockPatternLuma specifies the following. If CodedBlockPatternLuma is equal to 0, all AC transform coefficient levels of the luma, Cb, and Cr components of the macroblock are equal to 0 for all 16 of the 4x4 blocks in the luma, Cb, and Cr components of the macroblock. Otherwise (CodedBlockPatternLuma is not equal to 0), CodedBlockPatternLuma is equal to 15, at least one of the AC transform coefficient levels of the luma, Cb, or Cr components of the macroblock shall be non-zero, and the AC transform coefficient levels are scanned for all 16 of the 4x4 blocks in the luma Cb, and Cr components of the macroblock. Otherwise (the macroblock prediction mode is not equal to tra_16x16), coded_block_pattern is present in the bitstream, and the following applies: If ChromaArrayType is not equal to 3, each of the four LSBs of CodedBlockPatternLuma specifies, for one of the four 8x8 luma blocks of the macroblock, the following. If the corresponding bit of CodedBlockPatternLuma is equal to 0, all transform coefficient levels of the luma transform blocks in the 8x8 luma block are equal to zero. O