Hierarchical Approach to Efficient Intra Encoding in H.264/AVC and Its Deployments

• Main Authors: Kuo-Hsiang Cheng, 鄭國祥
• Other Authors: Ying-Hong Wang
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/18028147684704705387

博士 === 淡江大學 === 資訊工程學系博士班 === 102 === The H.264/AVC video coding standard can achieve higher coding efficiency than any other previous coding standards, such as MPEG-2, MPEG-4, and H.263. In order to improve the coding efficiency, the H.264/AVC encoder employs various prediction modes in the intra coding and adopts the rate-distortion optimization (RDO) method for selection of an optimum mode. Since the encoder computes the rate-distortion (RD) costs of all possible coding modes to decide the optimum mode, the computational complexity is dramatically increased. In this study, an efficient hierarchical approach which consists of the four algorithms: 1) fast intra skip decision; 2) quant-based block size selection decision; 3) direction-based prediction mode decision; and 4) fast partial intra skip decision for H.264/AVC intra encoding is proposed to reduce the computational complexity. Our experimental results have shown that the proposed algorithms outperform the previous methods. Our overall algorithm can significantly reduce above 85% encoding time for low-resolution video sequences on average, and reduce above 90% encoding time for high-resolution video sequences on average, while the PSNR degradation is negligible and the bit rate increment is minimal.