Patent ID: 7240014

Claim:
An audio signal recording disc encoded by a method which comprises the steps of: implementing matrix operation among first multiple-channel digital audio signals including front channels and surround channels to generate second multiple-channel audio signals correlating with each other, the first multiple-channel digital audio signals relating to a same sampling frequency; subjecting the second multiple-channel signals to lossless encoding to convert the second multiple-channel signals into an encoding-resultant signal from which a decoding side can reproduce the second multiple-channel audio signals; wherein the subjecting step comprises: 1) selecting a first sample among samples of each of the second multiple-channel audio signals for every prescribed interval of frame; 2) selecting one from each channel's different linear prediction methods and predictively encoding each of the second multiple-channel signals according to the selected one of each channel's different linear prediction methods, wherein the each channel's different linear prediction methods are of predicting each of the second multiple-channel audio signals from a past condition of each of the second multiple-channel audio signals for every prescribed interval of subframe which is a subdivision of the frame to generate each channel's different prediction signals for each of the second multiple-channel audio signals, and generating each channel's prediction-error signals representing differences between each of the second multiple-channel audio signals and each channel's different prediction signals respectively, and wherein selected each channel's linear prediction method generates a smallest of each channel's prediction-error signal; and 3) 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 selected first samples from said step 1) of selecting a first sample among samples of each of the second multiple-channel audio signals, the smallest each channel's prediction-error signals generated by the selected linear prediction method from said step 2), and an information piece representing the selected linear prediction methods from said step 2).