dividing an image frame to be coded into a plurality of sub-blocks, and assigning coordinates to each sub-block;

calculating a hash value corresponding to an i-th sub-block according to a content of the i-th sub-block;

performing a search in a first hash table by using the hash value corresponding to the i-th sub-block, so as to obtain coordinates corresponding to a first reference block, wherein a hash value corresponding to the first reference block is the same as the hash value corresponding to the i-th sub-block;

determining whether the coordinates of the first reference block are valid according to coordinates of the i-th sub-block;

in response to the coordinates of the first reference block being valid, acquiring a content of the first reference block according to the coordinates of the first reference block, and comparing the content of the first reference block with the content of the i-th sub-block;

in response to the content of the first reference block being consistent with the content of the i-th sub-block, performing Intra Block Copy (IBC) coding on the i-th sub-block;

replacing the coordinates corresponding to the first reference block in the first hash table with the coordinates corresponding to the i-th sub-block;

calculating a coordinate difference between the coordinates of the first reference block and the coordinates of the i-th sub-block; and

updating the second hash table to add the coordinate difference and the coordinates of the i-th sub-block;

wherein the i-th sub-block is any one of the plurality of sub-blocks;

wherein determining whether the coordinates of the first reference block are valid according to coordinates of the i-th sub-block further comprises:

determining whether a coordinate difference is within a preset range, wherein the coordinate difference is the difference between the horizontal and vertical coordinates of the first reference block and the horizontal and vertical coordinates of the i-th sub-block; and

when the coordinate difference is within the preset range, determining that the first reference block is valid.