Audio processor for extended the audio bandwidth of band-limited audio signal

Method for processing band-limited audio signal, comprising the steps:

• determining a temporal envelope from a linear prediction residual of the band-limited audio signal or an excitation modelling the linear prediction residual of the band-limited audio signal;
• wherein the determining comprises a redressing of the residual or the excitation signal to acquire a redressed residual signal or a redressed excitation signal;
• wherein the redressing is performed using resampling, or an absolute operation, or a power operation of a magnitude of the residual or excitation signal, or a processed version of the residual or excitation signal;
• analyzing the temporal envelope to determine certain values of the temporal envelope;
• analyzing comprising determining temporal values of local maxima or local minima as the certain values;
• generating an excitation, by placing pulses in relation to the determined certain values, wherein the pulses retained an amplitude of the time-domain envelope;
• wherein the pulses are weighted using weights derived from the temporal envelope;
• generating an extended-band audio signal by processing the generated excitation;
• combining the band-limited audio signal with the generated extended-band audio signal to acquire a frequency enhanced audio signal.

A non-transitory digital storage medium having a computer program stored thereon to perform the method for processing band-limited audio signal, comprising the steps:

• determining a temporal envelope from a linear prediction residual of the band-limited audio signal or an excitation modelling the linear prediction residual of the band-limited audio signal;
• wherein the determining comprises a redressing of the residual or the excitation signal to acquire a redressed residual signal or a redressed excitation signal;
• wherein the redressing is performed using resampling, or an absolute operation, or a power operation of a magnitude of the residual or excitation signal, or a processed version of the residual or excitation signal;
• analyzing the temporal envelope to determine certain values of the temporal envelope;
• analyzing comprising determining temporal values of local maxima or local minima as the certain values;
• generating an excitation, by placing pulses in relation to the determined certain values, wherein the pulses retained an amplitude of the time-domain envelope;
• wherein the pulses are weighted using weights derived from the temporal envelope;
• generating an extended-band audio signal by processing the generated excitation;
• combining the band-limited audio signal with the generated extended-band audio signal to acquire a frequency enhanced audio signal,
• when said computer program is run by a computer.