A Fast Macroblock Mode Decision Algorithm for H.264

Abstract

H.264 (JVT) is a new video coding standard jointly developed by ITU-T and ISO MPEG. H.264 uses many advanced techniques and has achieved superior performance compared with other video coding standards. In these techniques, multiple block size is an important part and could get nearly 20% bit rate reduction. However, searching all block sizes has remarkably increased the computational complexity of the H.264 codec. So an efficient mode selection method is very necessary here. In this paper, the authors propose a fast mode decision algorithm. The main techniques include: Pskip mode early detection based on transform domain, mode prediction, and early termination by using adaptive threshold. The authors also use post-search technique to keep coding quality and intra mode skip detection to save computational cost. Experiment results show that our algorithm saves a lot of computational cost. Compared with full mode selection, our new algorithm could keep the image quality quite well with almost the same bit rate