1. An audio encoder comprising: a spectral decomposer for spectrally decomposing, using an MDCT, an audio input signal into a spectrogram of a sequence of spectrums; an autocorrelation computer configured to compute an autocorrelation from a current spectrum of the sequence of spectrums; a linear prediction coefficient computer configured to compute linear prediction coefficients based on the autocorrelation; a spectral domain shaper configured to spectrally shape the current spectrum based on the linear prediction coefficients; and a quantization stage configured to quantize the spectrally shaped spectrum; wherein the audio encoder is configured to insert information on the quantized spectrally shaped spectrum and information on the linear prediction coefficients into a data stream, and wherein the autocorrelation computer is configured to, in computing the autocorrelation from the current spectrum, compute the power spectrum from the current spectrum, and subject the power spectrum to an inverse ODFT transform.