Method, medium, and system scalably encoding/decoding audio/speech

A method for scalably decoding an audio/speech signal, the method comprising:

• scalably decoding, performed by using at least one processing device, results of encoding a core layer and one or more extension layers, which are included in an result of encoding an input signal;
• reconstructing an SNR enhancement signal and a bandwidth enhancement signal by decoding results of encoding an SNR enhancement layer and a bandwidth enhancement layer which are included in the result of encoding the input signal;
• generating an addition signal by adding the reconstructed SNR enhancement signal to a reconstructed signal of the core layer and the extension layers;
• and
• combining the addition signal and the bandwidth enhancement signal.

A non-transitory computer readable recording medium having recorded thereon computer readable code to control at least one processing device to implement an executing of a method for scalably decoding an audio/speech signal, the method comprising:

• scalably decoding results of encoding a core layer and one or more extension layers, which are included in an result of encoding an input signal;
• reconstructing an SNR enhancement signal and a bandwidth enhancement signal by decoding results of encoding an SNR enhancement layer and a bandwidth enhancement layer which are included in the result of encoding the input signal;
• generating an addition signal by adding the reconstructed SNR enhancement signal to a reconstructed signal of the core layer and the extension layers;
• and
• combining the addition signal and the bandwidth enhancement signal.

A system for scalably encoding an audio/speech signal, the system comprising:

• a band splitting unit for splitting an input signal into a low frequency band signal that is lower than a predetermined frequency and a high frequency band signal that is higher than the predetermined frequency;
• an extension encoder/decoder, implemented by at least one processing device, for scalably encoding the split low frequency band signal into a core layer and one or more extension layers and then decoding the encoded core layer and the encoded extension layers;
• an error signal generation unit for generating an error signal by using the split low frequency band signal and a decoded signal of the encoded core layer and the encoded extension layers;
• and
• an enhancement layer encoding unit for encoding the error signal and the high frequency band signal into a signal-to-noise ratio (SNR) enhancement layer and a bandwidth extension layer.

A system for scalably decoding an audio/speech signal, the system comprising:

• an extension decoder for scalably decoding results of encoding a core layer and one or more extension layers, which are included in an result of encoding an input signal;
• an enhancement layer decoding unit, implemented by at least one processing device, for reconstructing an SNR enhancement signal and a bandwidth enhancement signal by decoding results of encoding an SNR enhancement layer and a bandwidth enhancement layer which are included in the result of encoding the input signal;
• an addition unit for generating an addition signal by adding the reconstructed SNR enhancement signal to a reconstructed signal of the core layer and the extension layers;
• and
• a band combination unit for combining the addition signal and the bandwidth enhancement signal.