US Patent 12095984 Sub-block based constraint on bi-prediction for out-of-boundary conditions

Whether one of (i) a boundary of a first reference subblock of a first subblock in a first reference picture is positioned beyond a boundary of the first reference picture and (ii) a boundary of a second reference subblock of the first subblock in a second reference picture is positioned beyond a boundary of the second reference picture is determined. Responsive to (i) the boundary of the first reference subblock of the first subblock in the first reference picture being beyond the boundary of the first reference picture and (ii) the boundary of the second reference subblock of the first subblock in the second reference picture being positioned within the boundary of the second reference picture, the first subblock of a current block is reconstructed based on a uni-prediction mode such that the first subblock is reconstructed based on the second reference subblock of the second reference picture.