Motion Compensated Interpolation as a New Inter Coding Mode for 8x8 Macroblock Partitions in H.264/AVC B Slices

Abstract

Thanks to a lot of new or improved coding tools, the H.264/AVC video coding standard achieves up to twice as good compression ratios over its predecessors. Unfortunately, many of these new coding tools come with the cost of a considerable extra amount of bits needed to send motion vectors to the decoder. Especially at low bit rates, this overhead is an important drawback. In this paper, a new inter coding mode for 8x8 macroblock partitions in B slices is proposed. The mode is based on motion compensated interpolation, a commonly used technique in the world of distributed video coding. Since motion compensated interpolation allows both encoder and decoder to find the same motion vector, no bits need to be spent on coding this motion vector. Experimental results show that introducing the new coding mode can achieve a bit rate gain of up to 3.03%, especially at low bit rates.