Audio Coding Using a Psychoacoustic Pre- and Post-Filter

A novel concept for perceptual audio coding is presented which is based on the addition of a pre- and post-filter controlled by a psychoacoustic model to a transform coding scheme. This allows to model the temporal and spectral shape of the masked threshold with a resolution independent on the used transform. By using frequency warping techniques in the filters the maximum possible detail for a given filter order can be made frequency-dependent and thus better adapted to the human auditory system. The filter coefficients are represented efficiently by LSF parameters which can be adaptively interpolated over time.