an acquisition section that sequentially acquires frame images drawn in a frame buffer;

a determination section that determines whether or not the frame image is an image quality priority image;

a basic parameter value decision section that decides, for the frame image that is not the image quality priority image, values of parameters used for encoding an encoding unit that is a part or whole of the frame image, by applying a difference between a control amount and a target value to a predetermined control rule;

an image quality priority parameter value decision section that decides, for the frame image that is the image quality priority image, values of parameters used for the encoding unit of the frame image;

an encoding processing section that generates image data by executing the encoding of the encoding unit on a basis of the values of the parameters decided by the basic parameter value decision section or the image quality priority parameter value decision section; and

a transmission section that transmits the image data,

wherein the image quality priority parameter value decision section decides, as the values of the parameters used for the encoding unit of the frame image, values by which a data size of the generated image data becomes larger than those decided by applying the difference between the control amount and the target value to the predetermined control rule, and

wherein the determination section determines that the frame image immediately after assets used for drawing the frame image are switched is the image quality priority image.