Video encoders and decoders and video encoding and decoding methods are provided. A video encoder includes an input buffer configured to receive a video data stream and to supply current frame data, a frame buffer configured to store reconstructed frame data, and an encoder circuit configured to read reference frame data from the frame buffer, to encode the current frame data received from the input buffer using the reference frame data and to write the reconstructed frame data to the frame buffer. The encoder circuit may be configured to write the reconstructed frame data by overwriting the reference frame data in the frame buffer.