Video decoding method and apparatus using multi-core transform, and video encoding method and apparatus using multi-core transform

A video encoding method comprising:

• splitting a current picture into a plurality of maximum coding units;
• splitting a maximum coding unit, among the plurality of maximum coding units, into a plurality of coding units including a current coding unit;
• generating information about a multi-core transformation according to a size of the current coding unit and whether a specific tool is applied or not, the information about the multi-core transformation indicating which transform kernel set among a plurality of transform kernel sets is to be applied, wherein the transform kernel set includes a horizontal transform kernel for transformation of the current coding unit in a horizontal direction and a vertical transform kernel for transformation of the current coding unit in a vertical direction;
• determining the horizontal transform kernel and the vertical transform kernel according to the information about the multi-core transformation;
• and
• performing the transformation of the current coding unit by using the horizontal transform kernel and the vertical transform kernel.

A non-transitory computer-readable medium for recording a bitstream, the bitstream comprising:

• information about a multi-core transformation,
• wherein, the information about the multi-core transformation is obtained by:
• splitting a current picture into a plurality of maximum coding units;
• splitting a maximum coding unit, among the plurality of maximum coding units, into a plurality of coding units including a current coding unit;
• generating the information about the multi-core transformation according to a size of the current coding unit and whether a specific tool is applied or not, the information about the multi-core transformation indicating which transform kernel set among a plurality of transform kernel sets is to be applied, wherein the transform kernel set includes a horizontal transform kernel for transformation of the current coding unit in a horizontal direction and a vertical transform kernel for transformation of the current coding unit in a vertical direction;
• determining the horizontal transform kernel and the vertical transform kernel according to the information about the multi-core transformation;
• and
• performing the transformation of the current coding unit by using the horizontal transform kernel and the vertical transform kernel.