PARAMETRIC AUDIO CODING COMPRISING BALANCED QUANTIZATION SCHEME

摘要

An audio encoder comprising a sinusoidal type encoder SE that generates, for each frame of an audio input signal IN, a set of sinusoidal components SC. For each frame, an optimum balance between number of sinusoidal components selected SS from the set of sinusoidal components together with a quantization scheme QS is found in terms of a predetermined encoding efficiency criterion. An encoded audio signal OUT comprising the selected set of sinusoidal components SS quantized according to the selected quantization scheme QS is then generated. Thus, the encoder is adapted to provide a high efficiency since it takes into account number of sinusoids to use for representing the input signal together with the quantization scheme. The encoder may be adapted to assign different quantization schemes for each one of the sinusoidal components. Preferably, the encoder is adapted to optimize encoding efficiency according to a perceptually relevant efficiency criterion, such as including a perceptual distortion measure PM. The quantization scheme may be assigned by high-rate quantization method or selected from a predefined set of quantization schemes.