Reconstructing an Audio Signal with a Noise Parameter

摘要

A method for reconstructing an audio signal having a baseband portion and a highband portion is disclosed. The method includes decoding an encoded audio signal to obtain a decoded baseband audio signal, filtering the decoded baseband audio signal to obtain subband signals, and generating a high-frequency reconstructed signal by copying a number of consecutive subband signals. The method also includes adjusting a spectral envelope of the high-frequency reconstructed signal based on an estimated spectral envelope of the highband portion extracted from the encoded audio signal to obtain an envelope adjusted high-frequency signal, generating a noise component based on a noise parameter extracted from the encoded audio signal, and adding the noise component to the envelope adjusted high-frequency signal to obtain a noise and envelope adjusted high-frequency signal.

主权项

1. A method for reconstructing an audio signal having a baseband portion and a highband portion, the method comprising:
decoding an encoded audio signal to obtain a decoded baseband audio signal, the encoded audio signal including spectral components of the baseband portion and not including spectral components of the highband portion, wherein the number of baseband spectral components contained in the encoded audio signal is capable of varying dynamically; filtering the decoded baseband audio signal to obtain a plurality of subband signals; generating a high-frequency reconstructed signal by copying a number of consecutive subband signals of the plurality of subband signals; adjusting a spectral envelope of the high-frequency reconstructed signal based on an estimated spectral envelope of the highband portion extracted from the encoded audio signal to obtain an envelope adjusted high-frequency signal, wherein a frequency resolution of the estimated spectral envelope is adaptive; generating a noise component based on a noise parameter extracted from the encoded audio signal, the noise parameter indicating a level of noise contained in the highband portion; adding the noise component to the envelope adjusted high-frequency signal to obtain a noise and envelope adjusted high-frequency signal; combining the decoded baseband audio signal with the noise and envelope adjusted high-frequency signal to obtain a time-domain reconstructed audio signal; wherein the method is performed with one or more computing devices.