Motion hints mode for macroblock coding in bi-predictive slices

Recent advances in motion modelling have largely focused on careful partitioning of motion blocks in the vicinity of object boundaries. The need for such fine partitioning can be avoided by using motion hints which provide a global description of motion over specific domains. Experimental results show that, with a hybrid setting, more than 50% of the motion discontinuity macroblocks are coded using the motion hints mode in low bit rate cases. The use of this mode leads to a gain of prediction PSNR of 1.11 dB, or equivalently 17.05% savings in bit rate, when compared to the H.264/AVC reference and considering both low and high bit rate applications.