A method for early-splitting of HEVC inter blocks based on decision trees

The High Efficiency Video Coding (HEVC) standard provides a large improvement in terms of compression efficiency in comparison to its predecessors, mainly due to the introduction of new coding tools and more flexible data structures. However, since much more options are tested in a Rate-Distortion (R-D) optimization scheme, such improvement is accompanied by a significant increase in the encoding computational complexity. We propose in this paper a novel method for efficient early-splitting decision of inter-predicted Coding Blocks (CB). The method employs a set of decision trees which are trained using information from unconstrained HEVC encoding runs. The resulting early-splitting decision process has an accuracy of 86% with a negligible computational overhead and an average computational complexity decrease of 42% at the cost of a very small Bjontegaard Delta (BD)-rate increase (0.3%).