QUALCOMM Incorporated
Bi-directional optical flow in video coding

Abstract:

A video coder is configured to code a block of video data using bi-prediction with bi-directional optical flow. The video coder may determine an offset using bi-directional optical flow and may add the offset to prediction samples determined from the bi-prediction. In one example, the video coder code a current block of video data using bi-prediction and bi-directional optical flow, wherein the bi-directional flow does not include one or more of a rounding operation or a division by 2 in an offset calculation. Additionally, the video coder may perform a motion vector refinement calculation for the bi-directional flow, wherein the motion vector refinement calculation is compensated to account for the offset calculation not including the division by 2.