1. A method of decoding video, the method comprising: receiving, by a decoding apparatus, a bitstream including inter prediction type information indicating whether list0 prediction, list1 prediction, or bi-prediction is applied to a current block; deriving, by the decoding apparatus, a value of the inter prediction type information based on the bitstream; determining, by the decoding apparatus, an inter prediction type for the current block based on the value of the inter prediction type information; and performing, by the decoding apparatus, an inter prediction based on the inter prediction type, wherein whether the bi-prediction is not available for the current block is determined based on a size of the current block.