Abstract: Provided are a method and an apparatus for determining an encoding mode for improving the quality of a reconstructed audio signal. A method of determining an encoding mode includes determining one from among a plurality of encoding modes including a first encoding mode and a second encoding mode as an initial encoding mode in correspondence to characteristics of an audio signal, and if there is an error in the determination of the initial encoding mode, generating a modified encoding mode by modifying the initial encoding mode to a third encoding mode.

Abstract: Provided are a method and an apparatus for determining an encoding mode for improving the quality of a reconstructed audio signal. A method of determining an encoding mode includes determining one from among a plurality of encoding modes including a first encoding mode and a second encoding mode as an initial encoding mode in correspondence to characteristics of an audio signal, and if there is an error in the determination of the initial encoding mode, generating a modified encoding mode by modifying the initial encoding mode to a third encoding mode.

Abstract: The present invention relates to an audio encoding and, more particularly, to a signal classifying method and device, and an audio encoding method and device using the same, which can reduce a delay caused by an encoding mode switching while improving the quality of reconstructed sound. The signal classifying method may comprise the operations of: classifying a current frame into one of a speech signal and a music signal; determining, on the basis of a characteristic parameter obtained from multiple frames, whether a result of the classifying of the current frame includes an error; and correcting the result of the classifying of the current frame in accordance with a result of the determination. By correcting an initial classification result of an audio signal on the basis of a correction parameter, the present invention can determine an optimum coding mode for the characteristic of an audio signal and can prevent frequent coding mode switching between frames.

Abstract: Provided are a method and an apparatus for determining an encoding mode for improving the quality of a reconstructed audio signal. A method of determining an encoding mode includes determining one from among a plurality of encoding modes including a first encoding mode and a second encoding mode as an initial encoding mode in correspondence to characteristics of an audio signal, and if there is an error in the determination of the initial encoding mode, generating a modified encoding mode by modifying the initial encoding mode to a third encoding mode.

Abstract: A method of enhancing speech quality includes: generating a high-frequency signal by using a low-frequency signal in a time domain; combining the low-frequency signal with the high-frequency signal; transforming the combined signal into a spectrum in a frequency domain; determining a class of a decoded speech signal; predicting an envelope from a low-frequency spectrum obtained in the transforming; and generating a final high-frequency spectrum by applying the predicted envelope to a high-frequency spectrum obtained in the transforming.

Abstract: The present invention relates to an audio encoding and, more particularly, to a signal classifying method and device, and an audio encoding method and device using the same, which can reduce a delay caused by an encoding mode switching while improving the quality of reconstructed sound. The signal classifying method may comprise the operations of: classifying a current frame into one of a speech signal and a music signal; determining, on the basis of a characteristic parameter obtained from multiple frames, whether a result of the classifying of the current frame includes an error; and correcting the result of the classifying of the current frame in accordance with a result of the determination. By correcting an initial classification result of an audio signal on the basis of a correction parameter, the present invention can determine an optimum coding mode for the characteristic of an audio signal and can prevent frequent coding mode switching between frames.

Abstract: Provided are a method and an apparatus for determining an encoding mode for improving the quality of a reconstructed audio signal. A method of determining an encoding mode includes determining one from among a plurality of encoding modes including a first encoding mode and a second encoding mode as an initial encoding mode in correspondence to characteristics of an audio signal, and if there is an error in the determination of the initial encoding mode, generating a modified encoding mode by modifying the initial encoding mode to a third encoding mode.

Abstract: The present invention relates to an audio encoding and, more particularly, to a signal classifying method and device, and an audio encoding method and device using the same, which can reduce a delay caused by an encoding mode switching while improving the quality of reconstructed sound. The signal classifying method may comprise the operations of: classifying a current frame into one of a speech signal and a music signal; determining, on the basis of a characteristic parameter obtained from multiple frames, whether a result of the classifying of the current frame includes an error; and correcting the result of the classifying of the current frame in accordance with a result of the determination. By correcting an initial classification result of an audio signal on the basis of a correction parameter, the present invention can determine an optimum coding mode for the characteristic of an audio signal and can prevent frequent coding mode switching between frames.

Abstract: A method of enhancing speech quality includes: generating a high-frequency signal by using a low-frequency signal in a time domain; combining the low-frequency signal with the high-frequency signal; transforming the combined signal into a spectrum in a frequency domain; determining a class of a decoded speech signal; predicting an envelope from a low-frequency spectrum obtained in the transforming; and generating a final high-frequency spectrum by applying the predicted envelope to a high-frequency spectrum obtained in the transforming.

Abstract: The present invention relates to an audio encoding and, more particularly, to a signal classifying method and device, and an audio encoding method and device using the same, which can reduce a delay caused by an encoding mode switching while improving the quality of reconstructed sound. The signal classifying method may comprise the operations of: classifying a current frame into one of a speech signal and a music signal; determining, on the basis of a characteristic parameter obtained from multiple frames, whether a result of the classifying of the current frame includes an error; and correcting the result of the classifying of the current frame in accordance with a result of the determination. By correcting an initial classification result of an audio signal on the basis of a correction parameter, the present invention can determine an optimum coding mode for the characteristic of an audio signal and can prevent frequent coding mode switching between frames.

Abstract: Provided are a method and an apparatus for determining an encoding mode for improving the quality of a reconstructed audio signal. A method of determining an encoding mode includes determining one from among a plurality of encoding modes including a first encoding mode and a second encoding mode as an initial encoding mode in correspondence to characteristics of an audio signal, and if there is an error in the determination of the initial encoding mode, generating a modified encoding mode by modifying the initial encoding mode to a third encoding mode.

Abstract: An audio encoding apparatus is provided that includes a transform unit to transform an audio signal in the time domain into an audio spectrum in the frequency domain; a bit allocation unit to determine the number of allocated bits by using spectral energy in predetermined frequency band units for the audio spectrum; and an encoding unit to determine the number of unit magnitude pulses for factorial pulse coding based on the number of allocated bits for the audio spectrum and to perform factorial pulse coding in the frequency band units for the audio spectrum by using the determined number of unit magnitude pulses.