Method for predicting bandwidth extension frequency band signal, and decoding device

摘要

A method for predicting a bandwidth extension frequency band signal includes demultiplexing a received bitstream to obtain a frequency domain signal; determining whether a highest frequency bin, to which a bit is allocated, of the frequency domain signal is less than a preset start frequency bin of a bandwidth extension frequency band; predicting an excitation signal of the bandwidth extension frequency band according to the determination; and predicting the bandwidth extension frequency band signal according to the predicted excitation signal of the bandwidth extension frequency band and a frequency envelope of the bandwidth extension frequency band.

主权项

1. A method for predicting a bandwidth extension frequency band signal of an audio signal and performed by a decoding device comprising a processor, comprising:
demultiplexing a received bitstream; decoding the demultiplexed bitstream to obtain a frequency domain signal; determining whether a highest frequency bin, to which a bit is allocated, of the frequency domain signal is less than a preset start frequency bin of a bandwidth extension frequency band; predicting an excitation signal of the bandwidth extension frequency band according to an excitation signal within a predetermined frequency band range of the frequency domain signal and the preset start frequency bin of the bandwidth extension frequency band when the highest frequency bin to which a bit is allocated is less than the preset start frequency bin of the bandwidth extension frequency band according to a process that comprises:
making n copies of the excitation signal within the predetermined frequency band range of the frequency domain signal; andusing the n copies of the excitation signal as an excitation signal between the preset start frequency bin of the bandwidth extension frequency band and a highest frequency bin of the bandwidth extension frequency band, wherein n is greater than 0, and wherein n is equal to a ratio of a quantity of frequency bins between the preset start frequency bin of the bandwidth extension frequency band and the highest frequency bin of the bandwidth extension frequency band to a quantity of frequency bins within the predetermined frequency band range of the frequency domain signal; predicting the excitation signal of the bandwidth extension frequency band according to the excitation signal within the predetermined frequency band range of the frequency domain signal, the preset start frequency bin of the bandwidth extension frequency band, and the highest frequency bin to which at least one bit is allocated when the highest frequency bin to which a bit is allocated is greater than or equal to the preset start frequency bin of the bandwidth extension frequency band; predicting the bandwidth extension frequency band signal according to the predicted excitation signal of the bandwidth extension frequency band and a frequency envelope of the bandwidth extension frequency band; and reconstructing the audio signal based on the predicted bandwidth extension frequency band signal.