Rate-distortion efficient amplitude modulated sinusoidal audio coding

In this paper, an improved parametric audio coder is presented. This coder addresses an important issue in audio coding, namely handling of transients. We propose a dedicated coder for transients based on amplitude modulated sinusoids. This coder is then combined with a constant-amplitude sinusoidal coder, and by rate-distortion optimization we choose which of the two is used for each segment. We show by rate-distortion curves and listening tests that the proposed coder offers significant improvements as compared to the constant-amplitude coder.