Patent ID: 8494863

Claim:
Audio coding system comprising: a linear prediction unit for filtering an input signal based on an adaptive filter; a transformation unit for transforming a frame of the filtered input signal into a transform domain; a long term prediction unit for determining an estimation of the frame of the filtered input signal based on a reconstruction of a previous segment of the filtered input signal; and a transform domain signal combination unit for combining, in the transform domain, the long term prediction estimation and the transformed input signal to generate a combined transform domain signal, a quantization unit for quantizing the combined transform domain signal; wherein the long term prediction unit comprises: a long term prediction extractor for determining a lag value specifying the reconstructed segment of the filtered signal that best fits the current frame of the filtered input signal; and a virtual vector generator to generate an extended segment of the reconstructed signal when the lag value is smaller than a frame length of the transformation unit, wherein the virtual vector generator applies an iterative fold-in fold-out procedure to refine the generated segment of the reconstructed signal, and wherein the audio coding system further comprises a processor coupled to one or more of the linear prediction unit, the transformation unit, the long term prediction unit, the transform domain signal combination unit, or the quantization unit.