High-Efficiency Mode Decision Procedure for H.264/AVC Under Cloud Computing Environments

The latest video coding standard, H.264/AVC, could achieve higher encoding performance compared with previous versions since it employs many tools to increase the coding accuracy, particularly the rate-distortion optimization technique for mode decision. However, enormous computational complexity is produced because all possible combinations of modes are calculated in order to find the optimal Rate-Distortion Cost, which will bring huge computational stress, particularly under cloud computing environments. To conquer this problem, a high-efficiency mode decision procedure for H.264/AVC under cloud computing environment is proposed in this paper. First, a fast intramode-type selection algorithm is presented to determine the intraprediction block size in advance. Then, the original multiple mode candidates for each prediction type are reduced at least by half with the information abstracted from macroblock and its 4×4 subblocks. The simulation results show that the proposed algorithm could reduce around 84% encoding time in average while maintaining the encoding performance efficiently with slight decrease in peak signal-to-noise ratio and increase in bit rate compared with H.264 reference software. It also produces better coding efficiency compared with the existing novel algorithms and could be widely used for multimedia communication systems with H.264/AVC standard under cloud computing environments.