Aspects of the disclosure provide methods, apparatuses, and a non-transitory computer-readable medium for video encoding/decoding. In a method, prediction information of a current block of a coding tree unit (CTU) in a coded bitstream is decoded. The prediction information indicates that the current block is coded in intra block copy (IBC) mode. A reference block is determined for the current block. A number of memory regions that contain samples of the reference block is less than a total number of memory regions for the CTU. The current block is reconstructed based on the reference block.