Low-delay audio signal coder, using analysis-by-synthesis techniques

Abstract From the Canadian patent

The low-delay audio signal coding system using, analysis-by-synthesis techniques comprises means (AFC, AFD) for adapting the spectral parameters and the prediction order of synthesis filters (SYC SYD) in the, coder (CDA, CDB) and decoder (DA DB), and of perceptual, weighting filters (FP) in the coder at each frame starting from the reconstructed signal relevant to the previous frame. In the case of a CELP coder means (AGC, AGD) are also provided to adapt starting from the, reconstructed signal a factor, bound to the average, power of the input signal of the gain by which the, innovation vectors are weighted. (Fig. 2).