Patent ID: 6463410
Filing Date: 2002-10-08
Classification: G10L,H04B,H04S

Abstract:
An audio signal encoding apparatus comprising:first means for implementing matrix operation between a first audio signal and a second audio signal to generate a first channel signal and a second channel signal correlating with each other, the first audio signal and the second audio signal relating to a same sampling frequency; a lossless encoder subjecting the first channel signal and the second channel signal to lossless encoding to convert the first channel signal and the second channel signal into an encoding-resultant signal from which a decoding side can reproduce the first audio signal and the second audio signal: second means provided in the lossless encoder for selecting a first sample among samples of the first channel signal for every prescribed interval; third means provided in the lossless encoder for selecting a first sample among samples of the second channel signal for every prescribed interval; fourth means provided in the lossless encoder for selecting one from first different linear prediction methods and predictively encoding the first channel signal according to the selected one of the first different linear prediction methods, wherein the first different linear prediction methods are of predicting the first channel signal from a past condition of the first channel signal to generate first different prediction signals for the first channel signal, and generating first prediction-error signals representing differences between the first channel signal and the first different prediction signals respectively, and wherein the first linear prediction method selected by the fourth means generates a smallest of the first prediction-error signals; fifth means provided in the lossless encoder for selecting one from second different linear prediction methods and predictively encoding the second channel signal according to the selected one of the second different linear prediction methods, wherein the second different linear prediction methods are of predicting the second channel signal from a past condition of the second channel signal to generate second different prediction signals for the second channel signal, and generating second prediction-error signals representing differences between the second channel signal and the second different prediction signals respectively, and wherein the second linear prediction method selected by the fifth means generates a smallest of the second prediction-error signals; and sixth means provided in the lossless encoder for generating a signal of a predetermined format having a header information area and a user data area, and loading the user data area with the first sample selected by the second means, the first sample selected by the third means, the smallest first prediction-error signal generated by the fourth means, the smallest second prediction-error signal generated by the fifth means, an information piece representing the first linear prediction method selected by the fourth means, and an information piece representing the second linear prediction method selected by the fifth means.