Error correction and concealment techniques can be roughly classified into three categories: forward, post-processing, and
interactive methods. Forward error correction and concealment refer to those techniques in which the transmitter side adds such redundancy to the transmitted data that the receiver can easily correct or conceal the transmitted data even if there were transmission errors. Post-processing methods estimate the correct representation of erroneously received data. The
transmitter and the receiver may also co-operate in order to minimize the effect of transmission errors. These methods
utilize feedback information given by the receiver.