The server device 100 transmits media data of a media rate, calculated by the rate output means 102, to the client device 200 at a transmission rate calculated by the rate output means 102. The rate output means 102 uses an objective function, which uses a media rate and a transmission rate as variables and determines an evaluation value evaluating a combination of QoE and a delivery cost so as to correspond to the variables, and predetermined constrains, to calculate a combination of a media rate and a transmission rate with which the evaluation value is the highest. The client device 200 reproduces content based on the media data transmitted from the server device 100.