A video encoder includes: a motion compensation picture signal generator that generates a plurality of motion compensation picture signals in accordance with an encoding target signal and a plurality of reference pictures; a prediction signal generator that generates a prediction signal of the encoding target signal using the motion compensation picture signals; a prediction error signal generator that generates a prediction error signal representing a difference between the encoding target signal and the prediction signal; a selector that selects an entropy code assignment rule that is expected to minimize an information amount of an encoded state of the prediction error signal from a plurality of entropy code assignment rules for encoding the prediction error signal in accordance with the motion compensation picture signals; and an entropy encoder that generates encoded information from the prediction error signal in accordance with the selected entropy code assignment rule.