Apparatus and method for harmonicity-dependent tilt control of scale parameters in an audio encoder

A method for encoding an audio signal, comprising:

• converting the audio signal into a spectral representation;
• calculating a set of scale parameters based on the audio signal;
• processing the spectral representation, or at least part thereof, using the set of scale parameters, or a modified version thereof;
• generating an encoded representation of the scale parameters, or of the modified version of the scale parameters;
• wherein calculating includes calculating an amplitude-related measure for each band to obtain a set of amplitude-related measures, wherein calculating comprises performing a pre-emphasis operation to the set of amplitude-related measures, so that low frequency amplitudes are emphasized with respect to high frequency amplitudes according to a tilt value, or according to a pre-emphasis factor, wherein calculating comprises controlling the tilt value or controlling the pre-emphasis factor based on a harmonicity measure of the audio signal, to thereby obtain the set of scale parameters;
• generating an encoded audio signal comprising information on an encoded representation of the spectral representation, or the at least part thereof, and information on the encoded representation of the scale parameters or of the modified version of the scale parameters.

A non-transitory storage unit storing instruction which, when executed by a processor, cause the processor to control or perform the following method:

• converting the audio signal into a spectral representation;
• calculating a set of scale parameters based on the audio signal;
• processing the spectral representation, or at least part thereof, using the set of scale parameters, or a modified version thereof;
• generating an encoded representation of the scale parameters, or of the modified version of the scale parameters;
• wherein calculating includes calculating an amplitude-related measure for each band to obtain a set of amplitude-related measures, wherein calculating comprises performing a pre-emphasis operation to the set of amplitude-related measures, so that low frequency amplitudes are emphasized with respect to high frequency amplitudes according to a tilt value, or according to a pre-emphasis factor, wherein calculating comprises controlling the tilt value or controlling the pre-emphasis factor based on a harmonicity measure of the audio signal, to thereby obtain the set of scale parameters;
• generating an encoded audio signal comprising information on an encoded representation of the spectral representation, or the at least part thereof, and information on the encoded representation of the scale parameters or of the modified version of the scale parameters,
• wherein the instructions are executed by the processor.