 a macroblock pair): The macroblock within a macroblock pair that contains the samples in the top row of samples for the macroblock pair. For a field macroblock pair, the top macroblock represents the samples from the region of the top field or layer top field of the frame or layer frame that lie within the spatial region of the macroblock pair. For a frame macroblock pair, the top macroblock represents the samples of the frame or layer frame that lie within the top half of the spatial region of the macroblock pair. G.3.67 VCL NAL unit: A collective term for coded slice NAL units and prefix NAL units. Abbreviations The specifications in clause 4 apply. Conventions The specifications in clause 5 apply. Source, coded, decoded and output data formats, scanning processes, neighbouring and reference layer relationships The specifications in clause 6 apply with substituting SVC sequence parameter set for sequence parameter set. The specification in clause 6.3 also applies to layer pictures. Additionally, the following processes are specified. G.6.1 Derivation process for reference layer macroblocks This process is only invoked when no_inter_layer_pred_flagis equal to 0. Inputs to this process are: a luma location ( xP, yP) relative to the upper-left luma sample of the current macroblock, a variable fieldMbFlag specifying whether the current macroblock is a field or a frame macroblock, a one-dimensional array refLayerFieldMbFlag with RefLayerPicSizeInMbs elements specifying which macroblocks of the reference layer representation are field macroblocks and which macroblocks are frame macroblocks, a one-dimensional array refLayerMbType with RefLayerPicSizeInMbs elements specifying macroblock types for the macroblocks of the reference layer representation. Outputs of this process are: the macroblock address mbAddrRefLayer specifying the reference layer macroblock, a luma location xx, yB ) relative to the upper-left luma sample of the reference layer macroblock. Let currDQId be the current value of DQId and let levelIde be t