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High frequency regeneration of an audio signal with phase adjustment

  • US 9,767,816 B2
  • Filed: 03/30/2017
  • Issued: 09/19/2017
  • Est. Priority Date: 03/28/2002
  • Status: Expired due to Term
First Claim
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1. A method for reconstructing an audio signal having a baseband portion and a highband portion, the method comprising:

  • obtaining a decoded baseband audio signal by decoding an encoded audio signal, wherein the encoded audio signal includes spectral components of the baseband portion and does not include spectral components of the highband portion;

    obtaining a plurality of subband signals by filtering the decoded baseband audio signal;

    generating a high-frequency reconstructed signal by;

    copying a number of consecutive subband signals of the plurality of subband signals,obtaining an envelope adjusted high-frequency signal by adjusting, based on an estimated spectral envelope of the highband portion, a spectral envelope of the high-frequency reconstructed signal, wherein the estimated spectral envelope is extracted from the encoded audio signal,generating a noise component based on a noise parameter, wherein the noise parameter is extracted from the encoded audio signal, and wherein the noise parameter indicates a level of noise contained in the highband portion, andobtaining the high-frequency reconstructed signal by adding the noise component to the envelope adjusted high-frequency signal;

    obtaining a time-domain reconstructed audio signal by adjusting a phase of the high-frequency reconstructed signal and combining the decoded baseband audio signal and the high-frequency reconstructed signal to obtain a time-domain reconstructed audio signal;

    wherein the method is implemented, at least in part, by an audio decoding device comprising one or more hardware elements, and wherein the plurality of subband signals is generated with one or more Quadrature Mirror Filters (OMF).

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