一种结合G.719编解码器的参数立体声音频编解码扩展方法

发布时间：2018-01-15 13:24

本文关键词：一种结合G.719编解码器的参数立体声音频编解码扩展方法　出处：《北京理工大学学报》2014年02期 　论文类型：期刊论文

【摘要】：针对ITU-T G.719全频带音频编码标准尚不支持立体声压缩编码的问题,结合G.719编解码器提出并设计基于离散傅里叶变换(discrete Fourier transform,DFT)的参数立体声音频编解码扩展模块.输入音频信号进行DFT变换后在子带内提取相应的空间参数,并将左右声道下混为和声道;解码时,对和声道进行能量补充,分别运用等式法和基于Givens旋转的奇异值分解法(singular value decomposition,SVD)进行解码恢复.测试结果表明,在G.719中合理设计参数立体声编解码可以获得较好的压缩效果,对于平缓的音乐,等式法比奇异值分解法可解码得到稍高的音质,且复杂度较低;对于变化较快的音乐,奇异值分解法可得到相对较好的音质,但复杂度较高.
[Abstract]:The ITU-T G.719 full-band audio coding standard does not support stereo compression coding. A discrete Fourier transform based on discrete Fourier transform (DFT) is proposed and designed based on G. 719 codec. The input audio signal is transformed by DFT, and the corresponding spatial parameters are extracted in the sub-band, and the left and right sound channels are mixed into harmony channels. In decoding, the sum channel is supplemented with energy, and the singular value decomposition method based on Givens rotation is used to solve the problem of singular value decomposition using the equality method and the singular value decomposition method based on Givens rotation, respectively. The test results show that the reasonable design parameters of stereo coding and decoding in G. 719 can obtain better compression effect for flat music. Compared with the singular value decomposition method, the equality method can decode a little higher sound quality, and the complexity is lower. For the fast changing music, the singular value decomposition method can get better sound quality, but the complexity is higher.
【作者单位】：北京理工大学信息与电子学院;中国科学院声学研究所;
【基金】：国家自然科学基金资助项目(11161140319) 北京理工大学与瑞典爱立信公司国际合作项目
【分类号】：TN912.3
【正文快照】： 2008年ITU-T提出了一种可用于语音和音频的全频带(20Hz~20kHz)、低复杂度、高质量音频编码标准G.719[1].该标准基于变换编码技术,采用改进离散余弦变换(modified discrete transform,MDCT),结合格型矢量量化、频带扩展等技术,实现较低码率透明压缩,支持单声道压缩码率为32~128

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