Document Type

Conference Proceeding

Publication Title

Proceedings of SPIE - the International Society for Optical Engineering


Video coding in wireless environment requires lower computational complexity and lower energy consumption than that used in storage oriented or network oriented application. Although H.264/AVC standard provides considerable higher compression efficiency as compared to the previous standards, its complexity is significantly increased at the same time. In a H.264/AVC encoder, the most time-consuming components are variable block sizes motion estimation and mode decision using rate-distortion optimization (RDO). In this paper, we propose a novel fast inter-prediction mode decision by exploiting high correlation between rate-distortion costs (RD cost) of macroblocks in the current inter frame and their co-located macroblocks in the previous inter frame. Using this new algorithm, we can reduce a number of inter mode candidates and skip motion estimation for these modes. In addition, our algorithm can also decrease a number of tested intra modes. Simulation results show that our approach can save 20% to 50% encoding time, with a negligible PSNR loss less than 0.1 dB and bit rate increase no more than 2% for almost all the test sequences.



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