Method and apparatus for encoding and decoding high frequency for bandwidth extension
Disclosed are a method and apparatus for encoding and decoding a high frequency for bandwidth extension. The method includes: estimating a weight; and generating a high frequency excitation signal by applying the weight between random noise and a decoded low frequency spectrum.
1. A method of generating an excitation class, the method including:
receiving audio from an input device;
first determining, based on a result of signal classification, whether a current frame of the audio corresponds to a speech signal;
when the current frame does not correspond to the speech signal, second determining, based on a tonal characteristic, whether the current frame corresponds to one of a noisy signal and a tonal signal; and
generating, based on a result of the first determining and the second determining, an excitation class for the current frame,
wherein the excitation class for the current frame is one of a plurality of excitation classes,
wherein the plurality of excitation classes include a speech class, a tonal music class, and a non-tonal music class.
2. The method of claim 1 , wherein the second determining is performed by comparing the tonal characteristic with a threshold.
3. The method of claim 1 , wherein the generating the excitation class comprises generating, in response to the first determining, the speech class.
4. The method of claim 1 , wherein the generating the excitation class comprises generating, in response to the second determining, the tonal music class and the non-tonal music class.