A new error-mapping scheme for scalable audio coding

In scalable audio coders, such as the MPEG-4 SLS, error-mapping is used to map quantization errors in the core coder to an error signal before passing through bit-plane coding. In this paper, we propose a new error-mapping scheme that is derived by observing statistical properties of the error signal. Compared with the error-mapping in SLS, the proposed scheme improves coding efficiency as well as computational complexity of the coder. An average improvement of 9 points in MUSHRA score has been achieved by the proposed scheme in subjective listening tests. The proposed error-mapping adds a useful new tool to the existing toolset for constructing next-generation scalable audio coders.