Time-Varying Transform for High Quality Audio Communication Codecs

Kovesi B, Philippe P, Virette D. Time-Varying Transform for High Quality Audio Communication Codecs. In: AES Convention 124. Audio Engineering Society; 2008. Paper 7333. Available from: https://aes.org/publications/elibrary-page/?id=14463

@inproceedings{Kovesi2008_14463,
  author = {Kovesi, Balazs and Philippe, Pierrick and Virette, David},
  title = {{Time-Varying Transform for High Quality Audio Communication Codecs}},
  booktitle = {AES Convention 124},
  note = {Paper 7333},
  year = {2008},
  month = may,
  publisher = {Audio Engineering Society},
  url = {https://aes.org/publications/elibrary-page/?id=14463}
}

TY  - CPAPER
TI  - Time-Varying Transform for High Quality Audio Communication Codecs
AU  - Kovesi, Balazs
AU  - Philippe, Pierrick
AU  - Virette, David
T2  - AES Convention 124
M1  - Paper 7333
PY  - 2008
DA  - 2008/05/06
UR  - https://aes.org/publications/elibrary-page/?id=14463
PB  - Audio Engineering Society
LA  - en
AB  - High quality audio communication is a current challenge addressed by the standardisation committees. In this context, ITU and MPEG recently issued standards for high quality coding of both speech and music contents. Transform coding is used and allows quality commensurate with bit rates regardless of the audio content. Up to now, only constant transform sizes were used in these coding schemes since time varying transform needed lookahead for perfect reconstruction, hence adding further delay. In this paper we demonstrate how variable transform sizes can be used without affecting the coding delay. Based on the filterbank theory, a framework avoiding lookahead is presented. The quality improvement offered by the proposed solution is illustrated in the context of MPEG-4 Enhanced Low Delay AAC.
ER  -