基于子带域滤波的AC-35.1通路虚拟环绕声实现

Implementation of Virtual Reproduction of AC-3 5.1 Channel Surround Sound Based on Subband-domain Filtering

研究将5.1通路虚拟环绕声处理技术与Dolby AC-3的解码相结合,在AC-3的解码端对5.1通路信号实现虚拟声信号处理,并采用子带域滤波方式,使滤波处理在MDCT变换域进行。根据子带域滤波原理,提出了基于AC-3的MDCT分析/合成滤波器组的子带域滤波实现方法。该方法与一般的时域滤波方式相比,计算复杂度显著降低,有利于虚拟环绕声实时处理。在显著降低计算复杂度的同时,所提出的子带域滤波与时域滤波方式的输出结果经扬声器重放,具有等同的虚拟环绕声效果。

The virtual reproduction of 5.1 channel surround sound techniques integrated into Dolby AC-3 decoder is studied in the paper.In order to reduce the computation complexity,the virtual surround sound processing of AC-3 coded 5.1 channel signals is implemented in MDCT frequency domain by subband filtering method,and a subband-domain filtering method based on AC-3 MDCT analysis/synthesis filter banks is presented.Compared with the traditional time-domain filtering method,the presented method in this paper can greatly reduce the computational complexity with the equivalent virtual surround sound effect by two loudspeakers,which is important to the real-time implementation.