Helmrich C, Edler B (2016)
Publication Type: Conference contribution
Publication year: 2016
Publisher: IEEE
Pages Range: 639-643
Conference Proceedings Title: 2016 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)
Event location: Shanghai, China
ISBN: 978-1-4799-9988-0
DOI: 10.1109/ICASSP.2016.7471753
Contemporary perceptual audio coders, all of which apply the modified discrete cosine transform (MDCT), with an overlap ratio of 50%, for frequency-domain quantization, provide good coding quality even at low bit-rates. However, relatively long frames are required for acceptable low-rate performance also for quasi-stationary harmonic input, leading to increased algorithmic latency and reduced temporal coding resolution. This paper investigates the alternative approach of employing the extended lapped transform (ELT), with 75% overlap ratio, on such input. To maintain a high time resolution for coding of transient segments, the ELT definition is modified such that frame-wise switching between ELT (for quasi-stationary) and MDCT coding (for non-stationary or non-tonal regions), with complete time-domain aliasing cancelation and no increase in frame length, becomes possible. A new ELT window function with improved side-lobe rejection to avoid framing artifacts is also derived. Blind subjective evaluation of the switched-ratio proposal confirms the benefit of the signal-adaptive design.
APA:
Helmrich, C., & Edler, B. (2016). Signal-Adaptive Switching of Overlap Ratio in Audio Transform Coding. In 2016 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) (pp. 639-643). Shanghai, China: IEEE.
MLA:
Helmrich, Christian, and Bernd Edler. "Signal-Adaptive Switching of Overlap Ratio in Audio Transform Coding." Proceedings of the 2016 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Shanghai, China IEEE, 2016. 639-643.
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