Fast Ultra-mode Selection Algorithm for H.264/AVC Video Coding with Low Complexity
Jong-Ho Kim, Jechang Jeong · 2005
The emerging H.264/AVC video coding standard improves coding performance significantly by adopting many advanced techniques. This is achieved at the expense of great increasing encoder complexity. Specifically the intra prediction using RDO examines all possible combinations of coding modes, which depend on spatial directional correlation with adjacent blocks. For 44 luma blocks, there are 9 modes, and for 1616 luma and 88 chroma blocks, there are 4 modes, respectively. Therefore the number of mode combinations for each macroblock is 592. This paper presents a method to reduce the RDO complexity using simple directional masks and neighboring modes. According to the proposed method, we reduce the number of mode combinations to 132 at the most. Experimental results show the proposed method reduces the encoding time up to with negligible loss of PSNR and bitrate increase compared to the H.264/AVC exhaustive search.