ETRI Journal

Electronics and Telecommunications Research Institute (한국전자통신연구원)
권호 표지
DOI QR코드

DOI QR Code

A Low-Delay MDCT/IMDCT

  • Lee, Sangkil (Department of Radio Engineering, Chungbuk National University) ;
  • Lee, Insung (Department of Radio Engineering, Chungbuk National University)
  • Received : 2012.12.13
  • Accepted : 2013.03.21
  • Published : 2013.10.31
Download PDF
⟨ Previous Next ⟩

Abstract

This letter presents an algorithm for selecting a low delay for the modified discrete cosine transform (MDCT) and inverse MDCT (IMDCT). The implementation of conventional MDCT and IMDCT requires a 50% overlap-add (OLA) for a perfect reconstruction. In the OLA process, an algorithmic delay in the frame length is employed. A reduced overlap window and MDCT/IMDCT phase shifting is used to reduce the algorithmic delay. The performance of the proposed algorithm is evaluated by applying the low-delay MDCT to the G.729.1 speech codec.

Keywords

References

  1. J.P. Princen and A.B. Bradley, "Analysis/Synthesis Filter Bank Design Based on Time Domain Aliasing Cancellation," IEEE Trans. Acoustics, Speech, Signal Process., vol. 34, no. 5, Oct. 1986, pp. 1153-1161. https://doi.org/10.1109/TASSP.1986.1164954
  2. H.S. Malvar, "Lapped Transforms for Efficient Transform/Subband Coding," IEEE Trans. Acoustics, Speech, Signal Process., vol. 38, no. 6, June 1990, pp. 969-978. https://doi.org/10.1109/29.56057
  3. Xiph.Org Foundation, "Vorbis I Specification," Feb. 2012. http://xiph.org/vorbis/doc/Vorbis_I_spec.html
  4. M. Iwadare et al., "A 128 kb/s Hi-Fi Audio CODEC Based on Adaptive Transform Coding with Adaptive Block Size MDCT," IEEE Trans. Sel. Areas Commun., vol. 10, no. 1, Jan. 1992, pp. 138-144. https://doi.org/10.1109/49.124473
  5. J.-M. Valin et al., "A High-Quality Speech and Audio Codec with Less Than 10 ms Delay," IEEE Trans. Audio, Speech, Language Process., vol. 18, no. 1, Jan. 2010, pp. 58-67. https://doi.org/10.1109/TASL.2009.2023186
  6. T. Lee et al., "Adaptive TCX Windowing Technology for Unified Structure MPEG-D USAC," ETRI J., vol. 34, no.3, June 2012, pp. 474-477. https://doi.org/10.4218/etrij.12.0211.0404
  7. S. Ragot et al., "ITU-T G,729.1: An 8-32 kbit/s Scalable Wideband Coder Bitstream Interoperable with G.729 for Wideband Telephony and Voice Over IP," IEEE Int. Conf. Acoustics, Speech, Signal Process., Honolulu, HI, USA, Apr. 2007, pp. IV:529-IV:532.
  8. J.P. Princen, A.W. Johnson, and A.B. Bradley, "Subband/Transform Coding Using Filter Bank Designs Based on Time Domain Aliasing Cancellation," IEEE Int. Conf. Acoustics, Speech, Signal Process., vol. 12, 1987, pp. 2161-2164.