Multiple description coding of an audio stream by optimum recovery transforms

In this paper, we discuss a method of splitting one audio stream into two equal-quality streams and recover the original audio stream from only one of the split streams. From a mathematical consideration, it is found that the sum of errors of two recovered signals is equal to the power of the original signal if simple recovery is carried out. Next, we describe the optimum recovery transform. This method utilizes the covariance matrix of the signal to minimize the error of the recovered signal. We carried out several experiments to recover a signal from one of the split signals. The result showed that the optimum recovery transform gave better results than the simple recovery, while the best splitting transform differed according to the signal to be processed.