EXTRACTION METHOD AND DEVICE OF IMPORTANT FREQUENCY COMPONENTS OF AUDIO SIGNAL, AND ENCODING AND/OR DECODING METHOD AND DEVICE OF LOW BIT RATE AUDIO SIGNAL UTILIZING EXTRACTION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method and a device for extracting an audio signal having the important frequency components, an encoding/decoding method of a low bit rate audio signal, and the device for extracting the important frequency components.

SOLUTION: The extraction method of the important frequency components of the audio signal encodes the perceptibly important frequency components by: a step for calculating the perceptible importance of a signs like an SMR value by a psychology acoustic model with respect to the audio signal in a frequency domain; a step for selecting a signal of a frequency having a masking threshold value smaller than the audio signal in the frequency domain as at least one or more first important frequency components by the perceptible importance; and a step for extracting a spectral peak by taking a predetermined weighting value into consideration among the audio signals selected as at least one or more first important frequency components, to select as at least one or more second important frequency components to be used for encoding the audio signal in the frequency domain, thereby high sound quality can be provided at the low bit rate.

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