Expanded three-channel mid/side coding for three-dimensional multichannel audio systems

Shi Dong,Ruimin Hu,Yuhong Yang,Weiping Tu,Xiaochen Wang

doi:10.1186/1687-4722-2014-10

Shi Dong, Ruimin Hu + Show 3 more

Open Access

https://doi.org/10.1186/1687-4722-2014-10

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Abstract

Abstract Three-dimensional (3D) audio technologies are booming with the success of 3D video technology. The surge in audio channels makes its huge data unacceptable for transmitting bandwidth and storage media, and the signal compression algorithm for 3D audio systems becomes an important task. This paper investigates the conventional mid/side (M/S) coding method and discusses the signal correlation property of three-dimensional multichannel systems. Then based on the channel triple, a three-channel dependent M/S coding (3D-M/S) method is proposed to reduce interchannel redundancy and corresponding transform matrices are presented. Furthermore, a framework is proposed to enable 3D-M/S compress any number of audio channels. Finally, the masking threshold of the perceptual audio core codec is modified, which guarantees the final coding noise to meet the perceptual threshold constraint of the original channel signals. Objective and subjective tests with panning signals indicate an increase in coding efficiency compared to Independent channel coding and a moderate complexity increase compared to a PCA method.

Highlights

3D audio has attracted more attention and developed fast following the booming market of 3D movie
Considering that PCA is the best decorrelation transform theoretically and Independent channel coding is widely used for 22.2 multichannel compression, the experiment compared the proposed 3D-M/S method with PCA and Independent channel coding in bitrate, complexity and objective quality
We can see Independent channel coding achieves the best performance in this case; 3D-M/S degrades about 1 dB and PCA degrades nearly 7 dB

Summary

Introduction

3D audio has attracted more attention and developed fast following the booming market of 3D movie. When sound source is close to the center of two channels, transformed signal CT has less dynamic range with corresponding matrix M1, M2, and M3. M/S coding in three-dimensional space For diffuse audio sources like ambient sound, the multichannel signals are weakly correlated.

Results

Conclusion