1. A method of encoding a video by using dynamic range transformation based on content, the method comprising: performing inter prediction, through motion estimation, and intra prediction for a current region using image data in which a dynamic range of the current region is transformed based on content of an image of input video; performing transformation on residual data generated by the performing the intra prediction and the inter prediction, and performing quantization on a transformation coefficient generated by the performing the transformation; and performing entropy encoding on the quantized transformation coefficient and outputting a bitstream comprising the encoded data for the current region, wherein in the performing the intra prediction and the inter prediction, the intra prediction and the inter prediction are performed using the image data in which the dynamic range is transformed so that pixel values of the current region are expanded in a range of a maximum limit value through a minimum limit value represented as current bit depths of the pixel values, and wherein in the performing the intra prediction and the inter prediction, a value higher than a highest limit value from among the pixel values of the current picture is transformed to correspond to the maximum limit value, a value less than a lowest limit value from among the pixel values of the current picture is transformed to correspond to the minimum limit value, and pixel values between the highest limit value and the lowest limit value from among the pixel values of the current picture are transformed to correspond one to one with values between the maximum limit value and the minimum limit value.