Method for encoding/decoding video signal according to an intra block copy (IBC) mode, and apparatus therefor

One or more non-transitory computer readable media storing instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:

• decoding a current block according to an intra block copy (IBC) mode, wherein decoding the current block according to the IBC mode comprises:
• constructing an IBC merge candidate list for a current block;
• selecting one of the IBC merge candidates included in the IBC merge candidate list;
• deriving a block vector of the current block based on the selected IBC merge candidate;
• obtaining a prediction sample of the current block based on the block vector;
• and
• determining whether to update an IBC motion information table based on the block vector of the current block, wherein when a size of the current block is smaller than a threshold size, the IBC motion information table is not updated based on the block vector of the current block,
• wherein the IBC merge candidate list includes an IBC merge candidate derived based on the IBC motion information table,
• wherein the IBC motion information table includes an IBC motion information candidate derived from a block to which an IBC mode is applied before the current block, and
• wherein a maximum number of the IBC merge candidates that the IBC merge candidate list may include is determined based on information signaled via a sequence parameter set.

A system comprising:

• one or more processors;
• and
• one or more non-transitory computer readable media storing instructions that, when executed by the one or more processors, cause the one or more processors to perform operations comprising:
• encoding a current block according to an intra block copy (IBC) mode, wherein encoding the current block according to the IBC mode comprises:
• constructing an IBC merge candidate list for the current block;
• deriving a block vector of the current block;
• obtaining a prediction sample of the current block based on the block vector;
• encoding index information indicating one of the IBC merge candidates identical to the block vector of the current block;
• and
• determining whether to update an IBC motion information table based on the block vector of the current block, wherein when a size of the current block is smaller than a threshold size, the IBC motion information table is not updated based on the block vector of the current block,
• wherein the IBC merge candidate list includes an IBC merge candidate derived based on the IBC motion information table,
• wherein the IBC motion information table includes an IBC motion information candidate derived from a block to which an IBC mode is applied before the current block, and
• wherein a maximum number of the IBC merge candidates that the IBC merge candidate list may include is determined based on information signaled via a sequence parameter set.

One or more non-transitory computer readable media storing instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:

• encoding a current block according to an intra block copy (IBC) mode, wherein encoding the current block according to the IBC mode comprises:
• constructing an IBC merge candidate list for the current block;
• deriving a block vector of the current block;
• obtaining a prediction sample of the current block based on the block vector;
• encoding index information indicating one of the IBC merge candidates identical to the block vector of the current block;
• and
• determining whether to update an IBC motion information table based on the block vector of the current block, wherein when a size of the current block is smaller than a threshold size, the IBC motion information table is not updated based on the block vector of the current block,
• wherein the IBC merge candidate list includes an IBC merge candidate derived based on the IBC motion information table,
• wherein the IBC motion information table includes an IBC motion information candidate derived from a block to which an IBC mode is applied before the current block, and
• wherein a maximum number of the IBC merge candidates that the IBC merge candidate list may include is determined based on information signaled via a sequence parameter set.