MDCT Analysis of Sinusoids and Applications to Coding Artifacts Reduction.

Daudet L, Sandler MB. MDCT Analysis of Sinusoids and Applications to Coding Artifacts Reduction. In: AES Convention 114. Audio Engineering Society; 2003. Paper 5831. Available from: https://aes.org/publications/elibrary-page/?id=12551

@inproceedings{Daudet2003_12551,
  author = {Daudet, Laurent and Sandler, Mark B.},
  title = {{MDCT Analysis of Sinusoids and Applications to Coding Artifacts Reduction.}},
  booktitle = {AES Convention 114},
  note = {Paper 5831},
  year = {2003},
  month = mar,
  publisher = {Audio Engineering Society},
  url = {https://aes.org/publications/elibrary-page/?id=12551}
}

TY  - CPAPER
TI  - MDCT Analysis of Sinusoids and Applications to Coding Artifacts Reduction.
AU  - Daudet, Laurent
AU  - Sandler, Mark B.
T2  - AES Convention 114
M1  - Paper 5831
PY  - 2003
DA  - 2003/03/06
UR  - https://aes.org/publications/elibrary-page/?id=12551
PB  - Audio Engineering Society
LA  - en
AB  - One of the most noticeable (and difficult to remove) artifacts in low bit-rate audio codecs is the high-frequency amplitude modulations, so-called 'birdies' (or 'warbling' artifacts). In this paper, we investigate the theoretical reasons why such artifacts occur, and in particular we show that they cannot be avoided with complete representations, such as critically sampled subband schemes, under a simple thresholding / quantization operation. In the case of the Modified Discrete Cosine Transform (MDCT), that forms the basis of many current coders, it is possible to compute explicitly the time-dependency of the coefficients of a pure sinusoid. From this, we derive a simple pre-filtering algorithm, that suppresses most of the frequency lines prone to warbling.
ER  -