Efficient and scalable parametric stereo coding for low bitrate audio coding applications

A pseudo stereo or multi-channel generator for generating a stereo or multi-channel output signal, comprising:

• a calculator for calculating a smoothed stereo-width gain by smoothing stereo-width gain values over a time segment having several stereo-width parameters, a stereo-width gain value being a function of a corresponding stereo-width parameter, the stereo-width parameters representing degrees of similarity between a first channel and a second channel of a stereo signal or of a multi-channel signal;
• a gain device for applying the smoothed stereo width gain to a mono signal derived from a first channel and a second channel of a stereo signal or a multi-channel signal;
• and
• an attenuation device for applying an attenuation to the mono signal, the attenuation being such that an overall level value when changing a stereo width is not significantly altered.

Method of pseudo stereo or multi-channel generating a stereo or multi-channel output signal, comprising:

• calculating, by a calculator, a smoothed stereo-width gain by smoothing stereo-width gain values over a time segment having several stereo-width parameters, a stereo-width gain value being a function of a corresponding stereo-width parameter, the stereo-width parameters representing degrees of similarity between a first channel and a second channel of a stereo signal or of a multi-channel signal;
• applying, by a gain device, the smoothed stereo width gain to a mono signal derived from a first channel and a second channel of a stereo signal or a multi-channel signal;
• and
• applying, by an attenuation device, an attenuation to the mono signal, the attenuation being such that an overall level value when changing a stereo width is not significantly altered.