High efficiency video coding (HEVC) is the newest video codec to increase significantly the coding efficiency of its ancestor H.264/Advance Video Coding. However, the HEVC delivers a highly increased computation complexity. In this paper, a coding unit partitioning pattern optimization method based on particle swarm optimization (PSO) is proposed to reduce the computational complexity of hierarchical quadtree-based coding unit partitioning. The required coding unit partitioning pattern for exhaustive partitioning and the rate distortion cost are efficiently considered as the chromosome and the fitness function of the PSO, respectively. To reduce the computational time, the cellular automata-based (CA) rule based time limit is used in order to find out the best possible modes of operation. Compared to the current state of the art algorithms, this scheme is computationally simple and achieves superior reconstructed video quality (12% increase in PSNR compared to existing methods) at less computational complexity (overall delay by 40%), Increasing the bandwidth and reducing the errors.