Fast Mode Decision for H.264/AVC Encoder Based on Interblock Correlation

The up-to-date video coding standardH.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, an extremely high computational complexity isproduced because all possible combinations of modes are calculated in order to find the optimal rate-distortion cost. To reduce the encoding complexity, a fast intra/intercoding mode selection algorithm for the H.264/AVC video coding standard is proposed in this paper. According to the observation of intra/inter prediction mode of any MB and those of its four neighboring blocks from different real video sequences, we find that there exists a high mode correlation in intra/inter mode map of H.264/AVC. We exploit the interblock correlation in the intra/intermode domain to early terminate the rate-distortion optimization (RDO) calculations. Experimental results show that the proposed fast mode selection algorithm can yield more encoding-time saving effects with similar image quality as compared with existing fast methods.