Coding statistics based fast mode decision for multi-view video coding

Reduction of high computational complexity of multi-view video coding (MVC) is necessary for realization in consumer electronics. Since mode decision is one of the key computational bottlenecks of multi-view video encoders, this paper proposes a coding statistics based fast mode decision algorithm. First of all, a rate–distortion cost based fast DIRECT mode decision algorithm early terminates the mode decision process if possible. Next, the candidates for Inter modes are reduced by taking the advantage of the correlation between an optimal mode and motion cost. The proper thresholds to reduce the candidates for the above two fast algorithms can be easily derived from exponential functions at run time. Finally, motion vector difference based motion characteristics is referred to further speed up the mode decision process of Inter modes. The experimental results show that the proposed scheme reduces up to 70.82% of encoding time with negligible degradation of RD performance.

► We propose a fast DIRECT mode decision algorithm using RD cost of mode decision.
► We propose a fast Inter mode decision algorithm using the RD cost of motion estimation.
► We propose a fast Inter mode decision algorithm using motion vector difference.
► Candidates including DIRECT, Inter, and Intra modes are considered to be reduced.
► Thresholds for fast mode decision are derived from exponential functions given QP.