JVET-AC0187 Non-EE2: Template matching-based subblock motion refinement [L. Zhao, K. Zhang, Z. Deng, L. Zhang (Bytedance)] [late]

Initial version rejected as “placeholder”.

This contribution presents methods to refine subblock motion based on template matching (TM). Firstly, TM-based control points refinement is proposed for uni-directional affine candidates. Secondly, the motion shift to locate SbTMVP is also refined by TM. It is reported that on top of ECM-7.0, simulation results of the proposed method are as below:

RA: -0.09 % (Y), -0.12 % (U), -0.14 % (V), 107% (EncT), 102% (DecT)

LB: -0.13 % (Y), -0.12 % (U), -0.33 % (V), 111% (EncT), 108% (DecT)

It was commented that the runtime should be reduced for the performance vs. complexity tradeoff to be attractive. Current runtime is too high, which is due to two factors: additional template searches, and code being unoptimized.

It was agreed to investigate this in an EE, with runtime reduction expected.