A video coding mechanism is disclosed. The mechanism includes selecting a split mechanism to split a coding unit (CU) into sub-CUs for application of one or more transform units (TUs), the selection of the split mechanism based on comparing a CU width to a max TU width and comparing a CU height to a max TU height. The selected split mechanism is applied to the CU to obtain sub-CUs. A residual of one of the sub-CUs is determined. The residual includes a difference between sample values for the sub-CU and prediction samples for the sub-CU. The TUs are applied to transform the residual of the CU based on results of the selected split mechanism. A transformed residual for the CU is encoded into a bitstream.