Systems and methods are provided for selecting and applying an appropriate deblocking filter for improved coding efficiency and compression performance by partitioning a frame into a plurality of rectangular coding units (CUs) according to the QTBT frame partitioning scheme, selecting a first and a second CUs of the plurality of rectangular CUs, where the second CU is adjacent to the first CU, identifying a CU boundary shared by the first and second CUs, determining that at least one of the first or the second CU is non-square in shape, determining a first shape of the first CU and a second shape of the second CU, adaptively selecting a deblocking filter based on the first shape and the second shape, and applying the selected deblocking filter to pixels across the CU boundary.