Apparatus and Method for Generating a Bandwidth Extended Signal

A method for generating a bandwidth extended signal from an input signal, wherein the input signal is represented, for a first band by a first resolution data, and for a second band by a second resolution data, the second resolution being lower than the first resolution, the method comprising:

• generating a first patch from the first band of the input signal according to a first patching algorithm;
• generating a second patch from the first band of the input signal according to a second patching algorithm, wherein a spectral density of the second patch generated according to the second patching algorithm is higher than a spectral density of the first patch generated according to the first patching algorithm;
• scaling the input signal according to the first patching algorithm and according to the second patching algorithm or scaling the first patch and the second patch, so that the bandwidth extended signal fulfills the spectral envelope criterion;
• and
• combining the first patch, the second patch and the first band of the input signal to acquire the bandwidth extended signal.

A method for providing a bandwidth reduced signal based on an input signal, comprising:

• determining a spectral envelope data based on a high frequency band of the input signal;
• generating patch scaling control data for scaling the bandwidth reduced signal at a decoder or for scaling a first patch and a second patch by the decoder, so that a bandwidth extended signal generated by the decoder fulfills a spectral envelope criterion, wherein the spectral envelope criterion is based on the spectral envelope data, wherein the first patch is generated from a first band of the bandwidth reduced signal according to a first patching algorithm and a second patch is generated from the first band of the bandwidth reduced signal according to a second patching algorithm, wherein a spectral density of the second patch generated according to the second patching algorithm is higher than a spectral density of the first patch generated according to the first patching algorithm;
• combining a low frequency band of the input signal, the spectral envelope data and the patch scaling control data to acquire the bandwidth reduced signal;
• providing the bandwidth reduced signal for a transmission or storage.

A computer program with a program code for performing the method for generating a bandwidth extended signal from an input signal, wherein the input signal is represented, for a first band by a first resolution data, and for a second band by a second resolution data, the second resolution being lower than the first resolution, the method comprising:

• generating a first patch from the first band of the input signal according to a first patching algorithm;
• generating a second patch from the first band of the input signal according to a second patching algorithm, wherein a spectral density of the second patch generated according to the second patching algorithm is higher than a spectral density of the first patch generated according to the first patching algorithm;
• scaling the input signal according to the first patching algorithm and according to the second patching algorithm or scaling the first patch and the second patch, so that the bandwidth extended signal fulfills the spectral envelope criterion;
• and
• combining the first patch, the second patch and the first band of the input signal to acquire the bandwidth extended signal,
• when the computer program runs on a computer or a microcontroller.

A computer program with a program code for performing the method for providing a bandwidth reduced signal based on an input signal, the method comprising:

• determining a spectral envelope data based on a high frequency band of the input signal;
• generating patch scaling control data for scaling the bandwidth reduced signal at a decoder or for scaling a first patch and a second patch by the decoder, so that a bandwidth extended signal generated by the decoder fulfills a spectral envelope criterion, wherein the spectral envelope criterion is based on the spectral envelope data, wherein the first patch is generated from a first band of the bandwidth reduced signal according to a first patching algorithm and a second patch is generated from the first band of the bandwidth reduced signal according to a second patching algorithm, wherein a spectral density of the second patch generated according to the second patching algorithm is higher than a spectral density of the first patch generated according to the first patching algorithm;
• combining a low frequency band of the input signal, the spectral envelope data and the patch scaling control data to acquire the bandwidth reduced signal;
• providing the bandwidth reduced signal for a transmission or storage,
• when the computer program runs on a computer or a microcontroller.