nt in the bitstream, the variables CodedBlockPatternLuma and CodedBlockPatternChroma are derived as specified by Equation 7-35. When scan_idx_end is less than scan_idx_start and one of the following conditions is true, the variables CodedBlockPatternLuma and CodedBlockPatternChroma are set equal to 0: base_mode_flag is equal to 1, ase_mode_flag is equal to 0, the macroblock type is not equal to P_Skip, B_Skip, or _PCM, and the macroblock prediction mode is not equal to intra_16x16. When the macroblock type is not equal to P_Skip, B _Skip, or I_PCM, the following constraints shall be obeyed: a) When scan idx end is less than scan_idx_start, and the macroblock prediction mode is equal to Intra_16x16, the bitstream shall not contain data that result in derived values of CodedBlockPatternLuma and CodedBlockPatternChroma that are not equal to 0. When scan_idx_start is equal to 0, scan idx end is equal to 0, and the macroblock prediction mode is equal to Intra_16x16, the bitstream shall not contain data that result in a derived value of CodedBlockPatternLuma that is not equal to 0. When scan_idx_start is equal to 0 and scan_idx_end is equal to 0, the bitstream shall not contain data that result in a derived value of CodedBlockPatternChroma that is equal to 2. The meaning of CodedBlockPatternLuma and CodedBlockPatternChroma is specified in clause 7.4.5. residual_prediction_flag equal to 1 specifies that the residual signal of the current macroblock is predicted as specified in clause G.8 using the reference layer representation specified by ref_layer_dq_id. residual_prediction_flag equal to 0 specifies that the residual signal of the current macroblock is not predicted. When the syntax element residual_prediction_flag is not present, residual_prediction_flag shall be inferred as follows: Rec. ITU-T H.264 (01/2012) If all of the following conditions are true, residual_prediction_flag is inferred to be equal to default_residual_prediction_flag: slice_type is not equal to EI, InCropWindow( CurrMbAddr ) is equal to 1, base_