Patent ID: 9666201
Date: 2017-05-30
CPC Classifications: G10L

Claim:
1. A decoder implemented bandwidth extension method, comprising: receiving a bit stream encoded from an audio signal; performing decoding operations on the bit stream, wherein a low frequency signal is generated via the decoding operations, wherein a collection of parameters is acquired via the decoding operations, and wherein the collection of parameters comprises one or more of the following parameters: a linear predictive coefficient (LPC), a set of line spectral frequency (LSF) parameters, a pitch period, a decoding rate, an adaptive codebook contribution, and an algebraic codebook contribution; predicting a high-frequency gain according to the LPC, and any one of or a combination of: a voicing factor, a noise gate factor, a spectrum tilt factor, and a classification parameter; predicting a high frequency excitation signal by selecting a frequency band from a low frequency excitation signal according to a difference value between the LSF parameters, wherein the low frequency excitation signal is represented by a sum of the adaptive codebook contribution and the algebraic codebook contribution; and generating a high frequency band signal from the high frequency excitation signal and the high frequency gain to recover the audio signal.