As a parameter control unit that controls video encoding parameters regarding video encoding in a video encoding unit and transmission channel parameters regarding error correction coding and modulation in a channel coding/modulation unit so as to be linked to each other, a cross layer rate control unit is provided. The cross layer rate control unit performs variable control of the GOP size according to propagation changes by reducing the GOP size when the amount of change in the predicted value of the PHY transmission rate is larger than a determined amount of change and increasing the GOP size when the amount of change in the predicted value of the PHY transmission rate is equal to or less than the determined amount of change.