Method and apparatus to encode and decode an audio/speech signal
A method and apparatus to encode and decode an audio/speech signal is provided. An inputted audio signal or speech signal may be transformed into at least one of a high frequency resolution signal and a high temporal resolution signal. The signal may be encoded by determining an appropriate resolution, the encoded signal may be decoded, and thus the audio signal, the speech signal, and a mixed signal of the audio signal and the speech signal may be processed.
1. An apparatus for decoding an audio or speech signal, the apparatus comprising:
a determination unit configured to receive a signal in a bitstream as an input and determine whether the signal is encoded in a frequency domain or a time domain based on encoding information included in the bitstream;
a frequency domain decoding unit configured to loss-less decode and dequantize the signal when it is determined that the signal is encoded in the frequency domain;
a temporal noise shaping unit configured to perform a temporal noise shaping on the dequantized signal;
an inverse transform unit configured to inverse-transform the temporal noise shaped signal to a time domain signal;
a time domain decoding unit configured to reconstruct the signal by using a linear prediction based decoding when it is determined that the signal is encoded in the time domain; and
a high frequency generating unit configured to generate a high band signal using either the inverse-transformed signal or the reconstructed signal and output the high band signal.
2. The apparatus of claim 1 further comprising:
a stereo processing unit to generate a stereo signal from the high band signal and either the inverse-transformed signal or the reconstructed signal.
3. The apparatus of claim 1 , wherein the time domain decoding unit is configured to reconstruct the signal encoded in the time domain by using at least a long-term predictor.