Investigation on Balanced-Delay Filter-Bank for Encoding Multi-Channel Audio Signals

摘要

Various MPEG audio standards, such as MPEG Surround, MPEG Advanced Audio Coding (AAC), MPEG Spatial Audio Object Coding (SAOC) as well as MPEG-H 3D Audio, employ a similar powerful hybrid filter-bank. Even though the filter-bank introduces an unbalanced delay, the overall filter distortion is very low. However, when MPEG Surround encodes multi-channel audio, such as 22.2 channels, the whole filter-bank structure can form a multi-layer filtering. In this paper, we investigate a case of balancing the delay for minimizing the overall filter distortion. The results of the experiments using 22.2 multi-channel audio signals show that the proposed balanced-delay filter-bank is capable of increasing the Signal-to-Noise Ratio up to 8 dB.