Method and device for processing video signal

A method of encoding a video, the method comprising:

• obtaining a first prediction value for a current sample in a current block based an intra prediction mode of the current block and a first reference sample, the intra prediction mode being representative of a directional intra prediction mode, the first reference sample being located on a forward direction of the directional intra prediction mode from the current sample;
• and
• generating a final prediction value of the current sample in the current block by modifying the first prediction value based on a second reference sample,
• wherein the intra prediction mode of the current block is determined as one of either conventional intra prediction modes or extended intra prediction modes,
• wherein whether the intra prediction mode of the current block is determined as one of the conventional intra prediction modes or the extended intra prediction modes is determined based on a shape of the current block,
• wherein the second reference sample is located on an opposite direction of the directional intra prediction mode from the current sample,
• wherein the final prediction value is generated based on a weighted sum of the first prediction value and the second reference sample, and
• wherein modifying the first prediction value is performed in response that a size of the current block is greater than a threshold value.

A non-transitory computer-readable medium for storing data associated with a video signal, comprising:

• a data stream stored in the non-transitory computer-readable medium, the data stream comprising intra prediction mode information for intra prediction of a current block,
• wherein an intra prediction mode of a current block is determined based on the intra prediction mode information,
• wherein the intra prediction mode of the current block is determined as one of either conventional intra prediction modes or extended intra prediction modes,
• wherein whether the intra prediction mode of the current block is determined as one of the conventional intra prediction modes or the extended intra prediction modes is determined based on a shape of the current block,
• wherein, in response to a case that the intra prediction mode of the current block is a directional intra prediction mode, a first prediction value for a current sample in the current block is obtained based on a first reference sample located on a forward direction of the directional intra prediction mode from the current sample,
• wherein a final prediction value of the current sample in the current block is generated by modifying the first prediction value based on a second reference sample,
• wherein the second reference sample is located on an opposite direction of the directional intra prediction mode from the current sample,
• wherein the final prediction value is generated based on a weighted sum of the first prediction value and the second prediction value, and
• wherein the modification of the first prediction value is performed in response that a size of the current block is greater than a threshold value.