A video decoding method, a video decoding apparatus, a video encoding method, and a video encoding apparatus are disclosed. Coding determination information of a representative channel of a target block is shared as coding determination information of the target channel of the target block, and the decoding of the target block is performed using the coding determination information of the target channel. As the coding determination information of the representative channel is shared with other channels, the same coding determination information can be prevented from being repeatedly signaled. The efficiency of encoding and decoding with respect to the target block and the like can be improved through such prevention.