Compensation of unmasking noise for scalable transmission of three-dimensional multichannel sound

Abstract

Even if three-dimensional multichannel sound becomes available in broadcasting, backward compatibility to conventional sound systems will be necessary. There are two transmission formats that can achieve this requirement. One is the simulcast format, and the other is the channel-scalable format. Although the channel-scalable format is advantageous over the simulcast format in terms of the required data rate, the unmasking artifact cannot be avoided when matrix operations are used to realize scalability. To solve this problem, this paper proposes a novel approach that models the quantization noise signal with a polynomial expansion of a decoded signal and removes it from the decoded signal. A subjective evaluation revealed that the proposed method can alleviate the unmasking artifact in the scalable coding of 8.1- and 22.2-channel audio signals.