chromaEdgeFlag is equal to 1), the following applies: If the macroblock containing the sample Zo is an I PCM macroblock, qPz is set equal to the value of QPc that corresponds to a value of 0 for QPy as specified in clause 8.5.8. Otherwise (the macroblock containing the sample Zo is not an I PCM macroblock), qPz is set equal to the value of QPc that corresponds to the value QPy of the macroblock containing the sample Zo as specified in clause 8.5.8. The process specified in clause 8.7.2.2 is invoked with Po, qo, p1, q1, chromaEdgeFlag, bS, filterOffsetA, filterOffsetB, qPp, and qP as inputs, and the outputs are assigned to filterSamplesFlag, indexA, a, and B. The variable chromaStyleFilteringFlag is set by chromaStyleFilteringFlag = chromaEdgeFlag && ( ChromaArrayType (8-450) Depending on the variable filterSamplesFlag, the following applies: If filterSamplesFlag is equal to 1, the following applies: If bS is less than 4, the process specified in clause 8.7.2.3 is invoked with Pi and qi (i = 0..2), chromaEdgeFlag, chromaStyleFilteringFlag, bS, B, and indexAgivenasinput,and the outputis assignedto p'and q'i (i = 0..2). Otherwise (bS is equal to 4), the process specified in clause 8.7.2.4 is invoked with pi and qi (i = 0..3), chromaEdgeFlag, chromaStyleFilteringFlag, a, and given as input, and the output is assigned to p'i and q'i (i = 0..2). Otherwise (filterSamplesFlag is equal to 0), the filtered result samples p'i and q'i (i = 0..2) are replaced by the corresponding input samples Pi and qi: for i = 0..2, (8-451) for ri=0..2, q'i = qi (8-452) 8.7.2.1 Derivation process for the luma content dependent boundary filtering strength Inputs to this process are the input sample values Po and qo of a single set of samples across an edge that is to be filtered and verticalEdgeFlag. Output of this process is the variable bS. Let the variable mixedModeEdgeFlag be derived as follows: If MbaffFrameFlag is equal to 1 and the samples Po and qo are in different macroblock pairs, one of which is a field macroblock pair and the oth