An inter-frame coding circuit for encoding a television video signal to reduce the quantity of data to be transmitted. The coding circuit includes a motion detection circuit which produces a motion vector representative of motion contained in the television signal and an inter-frame prediction coder which is responsive to the motion vector and to the input television signal to produce a prediction error signal which indicates frame-to-frame variations in the television signal. Also included is a refresh circuit for spatially correlating the input signal on an intra-frame basis. To reduce or eliminate the possibility that an error in the signal is magnified, the motion vector is set to zero for a predetermined period in relation to an area or a portion of the video signal for which a refresh operation has just been completed. A transmission circuit transmits the motion vector signal, the prediction error signal, and a refresh execution signal which are used for reproducing the original video signal. A counterpart decoding circuit for receiving the transmitted signals and reproducing from them the original video signal is provided.