When prediction_type_mask[i][j] is not present, it may be inferred to be equal to 4.
The variable SamplePredictionFlag[i][j] may be set equal to (prediction_type_mask[i][j] & 1).
The variable MotionInformationPredictionFlag[i][j] may be set equal to ((prediction_type_mask[i][j] & 2)>>1).