A method for decoding a video signal, the method comprising: obtaining chroma component format information from a higher-level bitstream, the chroma component format information indicating a chroma format of a chroma component of a current block; and obtaining, based on the chroma component format information, width-related information (SubWidthC) which indicates a width of a chroma array in comparison with a width of a luma array of the current block and height-related information (SubHeightC) which indicates a height of the chroma array in comparison with a height of the luma array of the current block, characterised by obtaining x-axis scale information based on the width-related information or information on a color component of the current block; obtaining y-axis scale information based on the height-related information or information on the color component of the current block; determining a location of a left block as ( xCb - 1, yCb - 1 + ( cbHeight << scallFactHeight)), where xCb is an x-axis coordinate of a top-left sample of a current luma block, yCb is a y-axis coordinate of the top-left sample of the current luma block, cbHeight is a value of a height of the current block, and scallFactHeight is the y-axis scale information; determining a location of an upper block as ( xCb - 1 + (cbWidth << scallFactWidth), yCb - 1), where xCb is the x-axis coordinate of the top-left sample of the current luma block, yCb is the y-axis coordinate of the top-left sample of the current luma block, cbWidth is a value of a width of the current block, and scallFactWidth is the x-axis scale information; determining a weighting value based on code information of the left block and code information of the upper block, wherein if the left block is available, and a prediction mode of the left block is the intra prediction, the code information (isIntraCodedNeighbourA) of the left block is set to TRUE, wherein if the left block is not available, or the prediction mode of the left block is not intra prediction, the code information of the left block is set to FALSE, wherein if the upper block is available, and a prediction mode of the upper block is the intra prediction, the code information (isIntraCodedNeighbourB) of the upper block is set to TRUE, and wherein if the upper block is not available, or the prediction mode of the upper block is not intra prediction, the code information of the upper block is set to FALSE; obtaining first samples by predicting the current block in a merge mode; obtaining second samples by predicting the current block in an intra mode; and obtaining a combination prediction sample for the current block as a weighted sum of the first samples and the second samples using the weighting value. obtaining chroma component format information from a higher-level bitstream, the chroma component format information indicating a chroma format of a chroma component of a current block; and obtaining, based on the chroma component format information, width-related information (SubWidthC) which indicates a width of a chroma array in comparison with a width of a luma array of the current block and height-related information (SubHeightC) which indicates a height of the chroma array in comparison with a height of the luma array of the current block, characterised by obtaining x-axis scale information based on the width-related information or information on a color component of the current block; obtaining y-axis scale information based on the height-related information or information on the color component of the current block; determining a location of a left block as ( xCb - 1, yCb - 1 + ( cbHeight << scallFactHeight)), where xCb is an x-axis coordinate of a top-left sample of a current luma block, yCb is a y-axis coordinate of the top-left sample of the current luma block, cbHeight is a value of a height of the current block, and scallFactHeight is the y-axis scale information; determining a location of an upper block as ( xCb - 1 + (cbWidth << scallFactWidth), yCb - 1), where xCb is the x-axis coordinate of the top-left sample of the current luma block, yCb is the y-axis coordinate of the top-left sample of the current luma block, cbWidth is a value of a width of the current block, and scallFactWidth is the x-axis scale information; determining a weighting value based on code information of the left block and code information of the upper block, wherein if the left block is available, and a prediction mode of the left block is the intra prediction, the code information (isIntraCodedNeighbourA) of the left block is set to TRUE, wherein if the left block is not available, or the prediction mode of the left block is not intra prediction, the code information of the left block is set to FALSE, wherein if the upper block is available, and a prediction mode of the upper block is the intra prediction, the code information (isIntraCodedNeighbourB) of the upper block is set to TRUE, and wherein if the upper block is not available, or the prediction mode of the upper block is not intra prediction, the code information of the upper block is set to FALSE; obtaining first samples by predicting the current block in a merge mode; obtaining second samples by predicting the current block in an intra mode; and obtaining a combination prediction sample for the current block as a weighted sum of the first samples and the second samples using the weighting value.