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Convention Paper

Optimal Quantized Linear Prediction Coefficients for Lossless Audio Compression - Scalar Quantization Revisited

Authors: Ghido, Florin

AES Convention 120 · Paper 6757 · May 2006

Abstract

Uniform scalar quantization of linear prediction coefficients with B bits is traditionally done by multiplying each coefficient with Q = 2B and rounding it to the nearest integer. We propose an improved, optimal quantization method by replacing the rounding with a more elaborated procedure. It uses on average 2 bits less per quantized prediction coefficient for a similar sum of squared errors and allows an accurate estimate of the mean squared error misadjustment as a function of Q for a given subframe and predictor order M. We introduce several efficient time-constrained probabilistic search methods for obtaining near optimal solutions. There are no required changes at the decoder and the method is applicable on a wider area of cases (mono, stereo, and multichannel prediction) than quantization of reflection coefficients. Moreover, the method enables near optimal compression for 24 bit audio using only 32 bit arithmetic operations.

Details

Published in
AES Convention 120
AES Convention
120
Paper number
6757
Publication date
May 6, 2006
Session subject
Signal Processing; High Resolution Audio
Affiliation
Tampere University of Technology (See document for exact affiliation information.)
Type
Convention Paper