Method and apparatus for encoding/decoding video and method for transmitting bitstream

An image encoding method performed by an image encoding apparatus, the image encoding method comprising:

• selecting an intra prediction mode of a current block;
• deriving a value of a reference sample filter flag based on coding parameters for the current block;
• determining whether to filter a reference sample for intra prediction of the current block based on the reference sample filter flag;
• selecting an interpolation filter applied to the reference sample for generating intra prediction samples of the current block based on the reference sample filter flag;
• generating the intra prediction samples of the current block using the selected interpolation filter;
• and
• encoding intra prediction mode information of the current block based on an intra prediction mode of a neighboring block located around the current block,
• wherein the intra prediction mode information of the current block comprises an index information for specifying one intra prediction mode among intra prediction mode candidates,
• wherein the coding parameters comprise at least one of a multi-reference line index of the current block, a size of the current block, a color component of the current block, whether to apply intra sub-partitions (ISP) to the current block or the intra prediction mode of the current block, and
• wherein the selecting the interpolation filter applied to the reference sample for generating the intra prediction samples of the current block based on the reference sample filter flag comprises:
• deriving a value of an interpolation filter flag for the intra prediction samples of the current block based on the reference sample filter flag;
• and
• selecting an interpolation filter based on the interpolation filter flag.

A method of transmitting a bitstream comprising:

• transmitting a bitstream generated by an image encoding method,
• wherein the image encoding method comprises:
• An image encoding method performed by an image encoding apparatus, the image encoding method comprising:
• selecting an intra prediction mode of a current block;
• deriving a value of a reference sample filter flag based on coding parameters for the current block;
• determining whether to filter a reference sample for intra prediction of the current block based on the reference sample filter flag;
• selecting an interpolation filter applied to the reference sample for generating intra prediction samples of the current block based on the reference sample filter flag;
• generating the intra prediction samples of the current block using the selected interpolation filter;
• and
• encoding intra prediction mode information of the current block based on an intra prediction mode of a neighboring block located around the current block,
• wherein the intra prediction mode information of the current block comprises an index information for specifying one intra prediction mode among intra prediction mode candidates,
• wherein the coding parameters comprise at least one of a multi-reference line index of the current block, a size of the current block, a color component of the current block, whether to apply intra sub-partitions (ISP) to the current block or the intra prediction mode of the current block, and
• wherein the selecting the interpolation filter applied to the reference sample for generating the intra prediction samples of the current block based on the reference sample filter flag comprises:
• deriving a value of an interpolation filter flag for the intra prediction samples of the current block based on the reference sample filter flag;
• and
• selecting an interpolation filter based on the interpolation filter flag.