A scalable low bitrate audio and speech coder

This paper presents a new scalable audio coding algorithm. The proposed coder consists of a wideband speech coder and embedded in a multi-layer transform coding algorithm. The transform coefficients are quantized using a scalable lattice vector quantization. With this technique, lattice codebooks of arbitrarily large bit rates can be generated algorithmically and the problem of lattice codebook overload can be bypass, and leads to a very fine grained scalability. The global system exhibits low computational complexity and memory requirement, and leads to a very fine grained scalability. The new coding algorithm is suitable for communications over heterogeneous network with no or uneven guarantee on the QoS for packet delivery.