Audio signal time-scale modification method using variable length synthesis and reduced cross-correlation computations

摘要

PURPOSE: A method of modifying time scale of an audio signal using variable length synthesis and correlation computation reduction technique is provided to reduce the quantity of calculations for finding the maximum value of cross-correlation. CONSTITUTION: An analysis window composed of the first number of audio samples of an input stream is decided(S16). Similarity between the first audio samples of the analysis window and the second audio samples of an output signal is calculated using the third and fourth audio sample blocks composed of audio samples down-selected from the first and second audio samples at a predetermined ratio. The similarity is calculated whenever the analysis window is shifted within a predetermined search range. A shift value of the analysis window when the maximum value among the calculated similarity values is provided is obtained(S18).