SNR scalability, multiple descriptions and perceptual distortion measures

SNR scalability and multiple descriptions (MD) coding are two important functionalities for speech coding applications. Previous analyses of these structures have not included frequency weighted error criteria. We present rate distortion theoretic results showing that the weighting functions in the core and enhancement layers for SNR scalable coding and in the side descriptions and the joint description for MD coding are necessarily different. We present simulation results for SNR scalable speech coding and MD speech coding to illustrate the theory.