A moving picture encoding device for encoding a moving picture constituted of a time sequence of frame pictures by motion compensation, the device comprising: a motion vector detection section configured to detect a motion vector of a predetermined area to be encoded in the frame picture; a prediction section configured to predict the motion vector of the predetermined area to be encoded, by using an encoded motion vector of a predetermined area in the frame picture; a determination section configured to set a predetermined motion vector indicating a predetermined pixel position based on the motion vector predicted by the prediction section, and configured to determine whether or not the motion vector detected by the motion vector detection section indicates the predetermined pixel position; wherein the determination section is configured to set the predetermined motion vector to either indicate a pixel position of (N+3/4, M+3/4) or a pixel position of (N+1/4, M+1/4), depending on the motion vector predicted by the prediction section where a phase of a vertical component PMVyE of the predicted motion vector is PMVyE%4 equals 0 or 1, or equals 2 or 3, with N and M being expressed in given integers; and a switching section configured to switch to a method of calculating a motion compensation value of the predetermined area to be encoded as an average of pixel values of neighboring integer pixel positions which surround the pixel position indicated by the motion vector detected by the motion vector detection section, if the motion vector detected by the motion vector detection section indicates the predetermined pixel position, wherein the predetermined motion vector is set to be different from the motion vector predicted by the prediction section. a motion vector detection section configured to detect a motion vector of a predetermined area to be encoded in the frame picture; a prediction section configured to predict the motion vector of the predetermined area to be encoded, by using an encoded motion vector of a predetermined area in the frame picture; a determination section configured to set a predetermined motion vector indicating a predetermined pixel position based on the motion vector predicted by the prediction section, and configured to determine whether or not the motion vector detected by the motion vector detection section indicates the predetermined pixel position; wherein the determination section is configured to set the predetermined motion vector to either indicate a pixel position of (N+3/4, M+3/4) or a pixel position of (N+1/4, M+1/4), depending on the motion vector predicted by the prediction section where a phase of a vertical component PMVyE of the predicted motion vector is PMVyE%4 equals 0 or 1, or equals 2 or 3, with N and M being expressed in given integers; and a switching section configured to switch to a method of calculating a motion compensation value of the predetermined area to be encoded as an average of pixel values of neighboring integer pixel positions which surround the pixel position indicated by the motion vector detected by the motion vector detection section, if the motion vector detected by the motion vector detection section indicates the predetermined pixel position, wherein