BOUNDARY EXTENSION FOR VIDEO CODING

Embodiments of the present disclosure provide a solution for boundary extension for video coding. In this solution, a boundary extension mode is determined for a current block in a current picture. A boundary of a reference picture is extended according to the determined boundary extension mode to generate an extended reference block for the current block. Inter-picture prediction is performed on the current block based on the extended reference block, to perform a conversion between the current block and an encoded representation of a video. First indication information indicating the boundary extension mode for at least one block including the current block is signaled in the encoded representation. Through this solution, the per-block extension provides high flexibility in boundary extensions and thus allows for unrestricted inter-picture prediction.