Fast block type decision algorithm for intra prediction in H.264 FRext

This paper presents a fast block type decision algorithm for 4×4, 8×8 and 16×16 intra prediction in H.264/AVC FRExt (fidelity range extension). With additional 8×8 intra prediction size, the complexity of intra prediction is increased by almost 50%. Thus, the proposed algorithm uses the smoothness of the macroblock to select the intra prediction block size and save computational cost. When further combining with our previously proposed three-step fast intra prediction algorithm, the proposed algorithm can save up to 32.1% and 63.4% of computation time of all I frames and intra prediction coding respectively, and achieves average 1.05% bit rate decrease and 0.046 dB quality degradation when comparing with the reference software.