Multiple description coding of predictively encoded sequences

We are concerned with multiple description coding of predictively encoded sequences at low rates/redundancies. The key problem to be solved is that of avoiding predictive mismatch. We propose an algorithm based on multiple description correlating transforms (MDCT), which avoids the problem of predictive mismatch while not increasing the number of transmitted coefficients. Under a general first-order, Gauss-Markov source model, carefully formulated to be applicable to the practically important case of video coding, we obtain closed-form expressions for the operational rate-distortion characteristics of the proposed algorithm and use these to optimize the algorithm encoding parameters. In the case of the residual-of-residuals technique, which is also based on MDCT, we show that incorporation of any redundancy between the transmitted descriptions is inherently suboptimal. Results show that the proposed algorithm significantly outperforms the residual-of-residuals technique at low rates.