A decoding device includes a controller classifying a bitstream as a first bitstream and a second bitstream based on a plurality of blocks defined by a matrix and included in a frame, a first decoder including a first processor performing decoding on the first bitstream and outputting first decoding data and a first memory, a second decoder including a second processor performing decoding on the second bitstream and outputting second decoding data and a second memory, a first buffer transmitting the first decoding data to the second memory, and a second buffer transmitting the second decoding data to the first memory. The first processor controls the second memory to store the first decoding data, and the second processor controls the first memory to store the second decoding data.