Abstract:
A multi-channel audio signal encoding and decoding method and apparatus are provided. The multi-channel audio signal encoding method, the method including: obtaining semantic information for each channel; determining a degree of similarity between multi-channels based on the obtained semantic information for each channel; determining similar channels among the multi-channels based on the determined degree of similarity between the multi-channels; and determining spatial parameters between the similar channels and down-mixing audio signals of the similar channels.
Abstract:
An audio reproducing method for quickly and correctly extracting extra data, including: receiving a data stream including the extra data including an end marker disposed immediately before main data and data length information, which is length information of the extra data, disposed immediately before the end marker; checking the presence/absence of the end marker; and if the end marker exists, extracting the extra data by using the data length information.
Abstract:
A method and apparatus for encoding a multi-channel audio signal is provided. The method includes the operations of selecting a first variable length code table (VLC) that is to be used to encode the multi-channel audio signal in a given frequency band, from among a plurality of VLC tables, and encoding the multi-channel audio signal by using the first VLC table. Thus, the multi-channel audio signal can be encoded by using VLC tables that differ according to frequency bands.
Abstract:
Provided are a method and apparatus for encoding the frequency of a continuation sinusoidal signal and a method and apparatus for decoding the same. In the encoding method, a continuation sinusoidal signal successive to a sinusoidal signal in a previous section is extracted from a current section; a frequency of the continuation sinusoidal signal at the boundary between the current and previous sections is changed to a first frequency, based on representative frequencies of the continuation sinusoidal signal and at least one sinusoidal signal that belongs to a section adjacent to the current section and is successive to the continuation sinusoidal signal; and the first frequency is encoded.
Abstract:
A method of implementing an equalizer in an audio signal decoder and an apparatus therefor are provided. According to the method and apparatus, a signal output from an audio signal decoder is not processed by an equalizer, but the values of frequency components are adjusted according to a user's input before subband sample data is transformed into a frequency domain signal in an audio signal decoder, thereby implementing an equalizer in a codec. In this way, the complexity of implementing an apparatus for reproducing an audio signal can be reduced and delay of an equalizer can be reduced.
Abstract:
Provided are audio encoding and decoding apparatuses capable of recovering a high-quality audio signal at a low bit rate. The audio encoding method includes: detecting at least one sinusoidal wave from an input audio signal; calculating components of additional basis vectors based on residual audio signals and the additional basis vectors of the sinusoidal wave; determining transmission of components of the additional basis vectors; and at least one of (a) encoding frequencies and (b) phases and amplitudes of the sinusoidal waves when the transmission of the components of the additional basis vectors are determined, wherein the residual audio signals are obtained by excluding the detected sinusoidal waves from the input audio signal.
Abstract:
Provided are methods and apparatuses for more efficiently encoding and decoding a high frequency band signal which is from an audio signal and which is greater than a predetermined threshold frequency. The method and apparatus for encoding the audio signal encodes a linear prediction coding (LPC) coefficient and gain information of a residual signal, which are generated by performing LPC analysis, thereby encoding a high frequency signal so as to have enhanced sound quality, while using less bits.
Abstract:
Provided are a method and apparatus for sinusoidal audio coding, which employs a tracking method for further effective coding of sinusoids extracted in the process of a sinusoidal analysis of parametric coding. The sinusoidal audio coding method includes: extracting sinusoids of a current frame by performing a sinusoidal analysis on an input audio signal; with respect to each of the extracted sinusoids, setting a mode selected from a birth mode in which a sinusoid is newly generated irrespective of sinusoids of a previous frame, a continuation mode in which the sinusoid is only one sinusoid continued from one of the sinusoids of the previous frame, and a branch mode in which the sinusoid is one of a plurality of sinusoids continued from one of the sinusoids of the previous frame; and coding the extracted sinusoids according to the selected mode. Accordingly, a plurality of sinusoids that can be continued from one previous track component are set to the continuation mode or the branch mode. Therefore, the number of bits of coded data is significantly reduced, compared with the case of the birth mode.
Abstract:
Provided is an audio encoding and decoding apparatus and method for improving a compression ratio while maintaining sound quality when sinusoidal waves of an audio signal are connected and encoded. The audio encoding method includes connecting sinusoidal waves of an input audio signal, converting a frequency of each of the connected sinusoidal waves to a psychoacoustic frequency, performing a first encoding operation for encoding the psychoacoustic frequency, performing a second encoding operation for encoding an amplitude of each of the connected sinusoidal waves, and outputting an encoded audio signal by mixing the encoding result of the first encoding operation and the encoding result of the second encoding operation.
Abstract:
Provided are a method and apparatus for encoding or decoding an audio signal by adaptively interpolating a linear predictive coding (LPC) coefficient. In the method and apparatus of encoding or decoding an audio signal, LPC coefficient interpolation is selectively performed depending on whether a transient section is present in a current frame, thereby preventing noise from occurring when interpolating LPC coefficients in the transient section.