Apparatus, medium and method to encode and decode high frequency signal
A method and apparatus to encoding or decoding an audio signal is provided. In the method and apparatus, a noise-floor level to use in encoding or decoding a high frequency signal is updated according to the degree of a voiced or unvoiced sound included in the signal.
1. A high band signal decoding apparatus comprising:
a high band signal generating unit to generate a high band signal by using a decoded low band signal;
a noise generation unit to generate a noise signal based on an extent of voicing in the decoded low band signal; and
a noise addition unit to add the noise signal to the high band signal.
2. The apparatus of claim 1 , wherein the noise generation unit generates the noise signal based on a difference between tonalities of the decoded low band signal and an original high band signal.
3. A high band decoding method comprising:
generating a high band signal by using a decoded low band signal;
generating a noise signal based on an extent of voicing in the decoded low band signal; and
adding the noise signal to the high band signal.
4. A high band decoding method comprising:
generating a high band signal by using a decoded low band signal in a linear prediction domain;
generating a noise signal based on an extent of voicing in the decoded low band signal; and
adding the noise signal to the high band signal.