A semiconductor device includes: an encoding processing unit that stores an encoded stream of an input data that is encoded based on the specified encoding control information; a buffer management unit that calculates the transmission buffer occupancy indicating the amount of data stored in a transmission buffer according to the generated data amount, and the reception buffer occupancy indicating the amount of data stored in a reception buffer, which is the destination of the encoded stream; and a control information specifying unit that, when the transmission buffer occupancy is equal to or less than a first threshold, specifies the encoding control information based on the reception buffer occupancy, and when the transmission buffer occupancy is greater than the first threshold, specifies the encoding control information to further reduce the generated data amount than in the case of equal to or less than the first threshold, to the encoding processing unit.