Intra block copy search range

A method for video decoding in a decoder, comprising:

• determining a current sub-block in a current block of a picture is to be reconstructed using intra block copy (IBC) based on a reference sub-block in the reconstructed block;
• determining whether reconstructed samples of the reference sub-block stored in a memory are available based on a comparison of a first value and a second value, the first value being based on a position of a top-left sample of the current sub-block in the current block relative to a top-left sample of the picture and the second value being based on a position covered by the reference sub-block, the availability of the reconstructed samples of the reference sub-block being indicative of whether the reference sub-block is overwritten;
• generating reconstructed samples of the current sub-block for output based on the reconstructed samples of the reference sub-block when the reconstructed samples of the reference sub-block stored in the memory are determined to be available, the determination that the reconstructed samples of the reference sub-block is available being indicative that the reconstructed samples of the reference sub-block are not overwritten;
• and
• overwriting reconstructed samples of a collocated sub-block in the reconstructed block stored in the memory with the generated reconstructed samples of the current sub-block.

A method of processing visual media data, the method comprising:

• performing a conversion between a visual media file and a bitstream of visual media data according to a format rule, wherein
• the bitstream includes at least one syntax element that indicates a current sub-block in a current block of a picture is to be reconstructed using intra block copy (IBC) based on a reference sub-block in the reconstructed block, and
• the format rule specifies that
• availability of reconstructed samples of the reference sub-block stored in a memory are based on a first value and a second value, the first value being based on a position of a top-left sample of the current sub-block in the current block relative to a top-left sample of the picture and the second value being based on a position covered by the reference sub-block, the availability of the reconstructed samples of the reference sub-block being indicative of whether the reference sub-block is overwritten,
• reconstructed samples of the current sub-block for output are generated based on the reconstructed samples of the reference sub-block when the reconstructed samples of the reference sub-block stored in the memory are determined to be available, the determination that the reconstructed samples of the reference sub-block is available being indicative that the reconstructed samples of the reference sub-block are not overwritten.