A low power video hardware engine is disclosed. The video hardware engine includes a video hardware accelerator unit. A shared memory is coupled to the video hardware accelerator unit, and a scrambler is coupled to the shared memory. A vDMA (video direct memory access) engine is coupled to the scrambler, and an external memory is coupled to the vDMA engine. The scrambler receives an LCU (largest coding unit) from the vDMA engine. The LCU comprises N×N pixels, and the scrambler scrambles N×N pixels in the LCU to generate a plurality of blocks with M×M pixels. N and M are integers and M is less than N.