Fast mode selection to reduce the encoding complexity of H.264/AVC

Fast mode selection is one of the hottest research topics for H.264/AVC finalized in 2003. Since the computational complexity is still a major challenge for real-time applications, simplification of mode selection is therefore very important. A fast mode selection algorithm is proposed in this paper. By removing low-probability modes according to the correlative characteristic in macroblock mode selection and the statistical characteristic of sub-macroblock mode selection, the calculation of mode selection process is significantly reduced. Based on the experimental results, the encoding time can be saved 55.91% on average, and in most cases the degradation of video quality is limited in 0.15 dB with less than 2% increase of bitrate.