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
Publication Date: April 1, 2002
Subject: Low Bit-Rate Audio Coding

Click to purchase paper as a non-member or you can login as an AES member to see more options.

No AES members have commented on this paper yet.

Subscribe to this discussion

To be notified of new comments on this paper you can subscribe to this RSS feed. Forum users should login to see additional options.

Start a discussion!

If you would like to start a discussion about this paper and are an AES member then you can login here:
Username:
Password:

If you are not yet an AES member and have something important to say about this paper then we urge you to join the AES today and make your voice heard. You can join online today by clicking here.