Multichannel object-based audio coding with controllable quality

In this paper a new multichannel object-based audio coding scheme with scalable signal quality is proposed. The novel scheme is based on controlled downmixing and demixing. By means of a dedicated control mechanism, a number of distinct audio objects are mixed into a lower number of channels. The latter is chosen such that the desired quality level is met after demixing. The quality is assessed with two new psychoacoustically motivated metrics. Following the informed source separation approach, the downmix is decomposed via optimum spatial filtering guided by short-time power spectral densities of the audio objects. In an experiment it is shown that the raw data rate of an exemplary 10-track recording can be reduced by at least 30 % using linear pulse-code modulation while maintaining perceptual transparency.