Hybrid Fast Mode Decision Algorithm for H.264/AVC High Profile

摘要

In order to reduce the computational complexity of H.264/AVC high profile, a hybrid fast mode decision algorithm is proposed in this paper. For each macroblock (MB), rate-distortion (RD) cost at SKIP mode is computed firstly for a possible early termination, once the RD cost value is below a pre-determined low threshold. On the other hand, if the RD cost value exceeds another high threshold, then only the intra modes are worthwhile to be checked. If the RD cost is between the above mentioned thresholds, the rest inter modes will be examined. At each stage of inter mode selection, temporal residual homogeneity and spatial residual homogeneity are checked for a possible early termination. In addition, the texture direction is predicted by exploiting the pixel direction error strengths for selecting the most possible candidate intra modes. Simulation results demonstrate that the proposed hybrid fast mode decision algorithm can achieve more than 60% timesaving than H.264 reference software JM16.1, with tiny degration of PSNR and less than 1% bit rate increase.