Scalable superwideband extension for wideband coding

Recent trends in speech and audio codec standardization include scalability and extending the signal bandwidth beyond wideband (WB) to superwideband (SWB). In this paper we introduce a SWB extension for the ITU-T G.718 WB codec. In the SWB extension the high frequency content is generated utilizing the quantized MDCT domain coefficients of the WB core, which enables low additional delay. The proposed implementation is scalable with 4 kbps layers. In the first layer two different coding modes are used depending on the input signal type. The proposed SWB extension is evaluated with listening tests and complexity analysis.

[1]  Minjie Xie,et al.  ITU-T G.722.1 Annex C: A New Low-Complexity 14 KHZ Audio Coding Standard , 2006, 2006 IEEE International Conference on Acoustics Speech and Signal Processing Proceedings.

[2]  Yang Gao,et al.  ITU-T G.729.1: AN 8-32 Kbit/S Scalable Coder Interoperable with G.729 for Wideband Telephony and Voice Over IP , 2007, 2007 IEEE International Conference on Acoustics, Speech and Signal Processing - ICASSP '07.

[3]  Anssi Rämö,et al.  ITU-T G.EV-VBR baseline codec , 2008, 2008 IEEE International Conference on Acoustics, Speech and Signal Processing.

[4]  Gerald Schuller,et al.  Spectral Band Replication Tool for Very Low Delay Audio Coding Applications , 2007, 2007 IEEE Workshop on Applications of Signal Processing to Audio and Acoustics.

[5]  Y. Wang,et al.  Some peculiar properties of the MDCT , 2000, WCC 2000 - ICSP 2000. 2000 5th International Conference on Signal Processing Proceedings. 16th World Computer Congress 2000.

[6]  Koji Yoshida,et al.  Efficient spectrum coding for super-wideband speech and its application to 7/10/15 kHz bandwidth scalable coders , 2004, 2004 IEEE International Conference on Acoustics, Speech, and Signal Processing.

[7]  Masahiro Oshikiri,et al.  ITU-T EV-VBR: A robust 8-32 kbit/s scalable coder for error prone telecommunications channels , 2008, 2008 16th European Signal Processing Conference.

[8]  Kristofer Kjörling,et al.  Spectral Band Replication, a Novel Approach in Audio Coding , 2002 .

[9]  Pasi Ojala,et al.  AMR-WB+: a new audio coding standard for 3rd generation mobile audio services , 2005, Proceedings. (ICASSP '05). IEEE International Conference on Acoustics, Speech, and Signal Processing, 2005..