Rate-distortion optimized hybrid sound coding

This paper presents a rate-distortion optimization approach to hybrid sound coding. The advantages of sinusoidal and transform coding are combined by a rate-distortion optimization mechanism, using a perceptually relevant distortion measure based on spectral auditory masking. As a result, the coder can adapt to the input signal and to constraints such as bit rate. Listening test results show improved performance of the hybrid coder compared to the individual coding paradigms. There is a good correlation between the improved performance as reported by the listeners and the differences in distortion resulting from the perceptually relevant distortion measure. This confirms that the distortion measure used in the optimization is useful; moreover, it shows the feasibility of the rate-distortion optimization approach for hybrid sound coding.