AES E-Library

High Order LPC and Line Spectrum Pairs

High order linear predictive coding (LPC) analysis, as a pre-preprocessing stage in an audio codec designed for wideband arbitrary audio signals, is found to be particularly beneficial for audio samples of an instrumental nature compared to that of a vocal nature. With increasing LPC orders, it is imperative to keep the bits consumed by the pre-processing stage constant as a proportion of the total bit rate. To achieve this, the properties of the Line Spectrum Pairs (LSP) parameter are exploited in a proposed multistage vector quantization scheme for high order LPC. Notably, incorporating LSP differences in the design of the quantizer was the most efficient, with no perceptible differences at an average of 1.645 bits/sample, compared to the case of scalar quantization, which is used as a benchmark at 2 bits/sample. Particularly, using LSP differences as a bit allocation mechanism proves to be especially effective in dealing with clips of a percussive nature.

Authors: Eng, Kelvin H. C.; Huang, Dong Yan; Foo, Say Wei
Affiliations: National University of Singapore, Department of Electrical Engineering, Singapore ; Institute of Microelectronics, VLSI, Singapore(See document for exact affiliation information.)
AES Convention:112 (April 2002) Paper Number:5572 Import into BibTeX
Subject:Low Bit-Rate Audio Coding

Click to purchase paper or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!

This paper costs $20 for non-members, $5 for AES members and is free for E-Library subscribers.

Learn more about the AES E-Library

E-Library Location: (CD aes19)   /pp2002/pp0205/000209.pdf

Start a discussion about this paper!