Joint speech/audio coding based scalable perceptual audio coding

With the technical evolution of global mobile communications, various heterogeneous communication environments, frequently fluctuant bandwidth and multiform signals put new challenges to coding technology of multimedia signals. Scalable Audio Coding (SAC) can provide smooth transition between different coding qualities, which is an optimal choice for coding audio signals of different types and can produce more reliable and consistent service quality in multimedia communications. A scalable audio coding system based on joint speech/audio coding method and an auditory perceptual importance model based on bit-plane are proposed here. Both the audio content and the network bandwidth fluctuation will be considered in the system to obtain stable service qualities in mobile multimedia services. Experimental results indicate that with the same bit rates the subjective quality of proposed method is slightly better than G.729.1 and the SNR is improved by 0.3dB.