Video decoding method and device
Provided are a video decoding method and device. This specification provides a video decoding method comprising the steps of: acquiring a parameter indicating whether a multiple transform set is applicable to a block to be decoded, as well as information about the width of the block to be decoded and the height of the block to be decoded; determining the transform type of the block to be decoded on the basis of at least one of the parameter indicating whether a multiple transform set is applicable, or the information about the width and height of the block to be decoded, and setting a zero-out region of the block to be decoded; and inverse-transforming the block to be decoded on the basis of the zero-out region of the block to be decoded and the result of determining the transform type.
1. A video decoding method performed by a video decoding device, the method comprising the steps of:
obtaining a parameter indicating whether a multiple transform set (MTS) can be applied to a decoding block, and information on a size of the decoding block;
determining a transform type of the decoding block based on at least one among the parameter indicating whether the multiple transform set (MTS) can be applied to the decoding block, and the information on the size of the decoding block; and
setting a zero-out area of the decoding block based on at least one among the parameter indicating whether the multiple transform set (MTS) can be applied to the decoding block, and the information on the size of the decoding block;
wherein
when the size of the decoding block is 64×64, 64×32, or 32×64, a valid area of the decoding block is set to the upper-left 32×32 area of the decoding block, and the remaining area of the decoding block except for the valid area is set to the zero-out area in which coefficient information are not signaled to the video decoding device,
when the size of the decoding block is 64×64, 64×32, or 32×64, the zero-out area is set regardless of the parameter,
when the size of the decoding block is 32×32, 32×16, or 16×32, the zero-out area is set considering the parameter and a size of the zero-out area for the parameter equal to a first value is different from a size of the zero-out area for the parameter equal to a second value.
2. The method according to claim 1 , wherein
when the size of the decoding block is 64×64, 64×32, or 32×64, the transform type of the decoding block is determined as DCT-II which is default transformation.
3. The method according to claim 1 , wherein
when the size of the decoding block is 16×16 or less, the entire area of the decoding block is set to the valid area, and the zero-out area does not exist in the decoding block.
4. The method according to claim 1 ,
whether or not syntax information with regard to a maximum size of a transform applied to the decoding block is signaled to the video decoding device depends on whether a block size is greater than a predetermined size.