US Patent 11523108 Position restriction for inter coding mode

A method of video processing includes determining, for a conversion between a current block of a first picture of a video and a bitstream representation of the video, a motion candidate based on motion information from a second picture according to a rule. The rule specifies that a position from which the motion information is accessed is constrained to be within a specific subpicture of the second picture. The method also includes performing the conversion based on the determining.