On integer MDCT for perceptual audio coding

作     者：Li, Te Rahardja, Susanto Yu, Rongshan Koh, Soo Ngee 

作者机构：Inst Infocomm Res I2R Singapore 119613 Singapore Nanyang Technol Univ Sch Elect & Elect Engn Singapore 639798 Singapore Dolby Labs San Francisco CA 94103 USA 

出 版 物：《IEEE TRANSACTIONS ON AUDIO SPEECH AND LANGUAGE PROCESSING》 (IEEE Trans. Audio Speech Lang. Process.)

年 卷 期：2007年第15卷第8期

页      面：2236-2248页

核心收录：

主　　题：integer modified discrete cosine transform (Int-MDCT) perceptual audio coding scalable lossless coding 

摘      要：In MPEG-4 scalable lossless coding (SLS) which was recently published as an ISO standard in June 2006, the integer modified discrete cosine transform (IntMDCT) was adopted to enable efficient lossless reconstruction. In addition, there is an MDCT filterbank which is inherent to the advanced audio coding (AAQ core that is present in the SLS codec. The presence of two filterbanks have undoubtedly increased the complexity of the implementation, and it is for this reason that the MDCT is disabled and the IntMDCT is then the only type of filterbank that is employed in SLS for both lossy and lossless operations. Because of the rounding operations in the IntMDCT, there is a concern if the use of IntMDCT for perceptual audio coding will eventually degrade the fidelity of the audio codec. This paper addresses this concern by analyzing the performance of the IntMDCT in a lossy coding scenario. It is found that noise introduced by the IntMDCT does not affect the perceptual quality of the coded audio under standard playback circumstances. As such, it concludes that the MDCT and IntMDCT filterbanks are interchangeable at lossy bitrate, and the way of using only the IntMDCT filterbank in scalable audio coding is also justified.