Adaptive transition frequency between noise fill and bandwidth extension

摘要

A method for spectrum recovery in spectral decoding of an audio signal, comprises obtaining (210) of an initial set of spectral coefficients representing the audio signal, and determining (212) a transition frequency. The transition frequency is adapted to a spectral content of the audio signal. Spectral holes in the initial set of spectral coefficients below the transition frequency are noise filled (214) and the initial set of spectral coefficients are bandwidth extended (216) above the transition frequency. Decoders and encoders being arranged for performing part of or the entire method are also illustrated.

主权项

1. A method for spectrum recovery in spectral decoding of an audio signal, the audio signal comprising a set of frames including a first frame and a second frame, the method comprising the steps of:
an audio decoding apparatus obtaining a first set of spectral coefficients representing only said first frame of said audio signal; the audio decoding apparatus determining a first transition frequency (ft) for said first frame of said audio signal; the audio decoding apparatus determining a second transition frequency (ft2) for said second frame of said audio signal; the audio decoding apparatus noise filling of spectral holes in said first set of spectral coefficients below said first transition frequency (ft); and the audio decoding apparatus bandwidth extending said first set of spectral coefficients above said transition frequency (ft), wherein determining said first transition frequency (ft) comprises selecting said first transition frequency (ft) based on a distribution of spectral holes in said first set of spectral coefficients representing only said first frame of said audio signal.