Patent ID: 8078456

Claim:
A method for time scale modifying an input audio signal that includes a series of input audio signal samples, comprising: obtaining an input frame size for a next frame of the input audio signal to be time scale modified, wherein the input frame size may vary on a frame-by-frame basis; shifting a first buffer by a number of samples equal to the input frame size and loading a number of new input audio signal samples equal to the input frame size into a portion of the first buffer vacated by the shifting of the input buffer; calculating a waveform similarity measure or waveform difference measure between a first portion of the input audio signal stored in the first buffer and each of a plurality of portions of an audio signal stored in a second buffer to identify a time shift; overlap adding the first portion of the input audio signal stored in the first buffer to a portion of the audio signal stored in the second buffer and identified by the time shift to produce an overlap-added audio signal in the second buffer; providing a number of samples equal to a fixed output frame size from a beginning of the second buffer as a part of a time scale modified audio output signal; and shifting the second buffer by a number of samples equal to the fixed output frame size and loading a second portion of the input audio signal that immediately follows the first portion of the input audio signal in the first buffer into a portion of the second buffer that immediately follows the end of the overlap-added audio signal in the second buffer after the shifting of the second buffer.