Abstract: A method of encoding stereo audio that minimizes a number of pieces of side information required for parametric-encoding and parametric-decoding of the stereo audio. The side information may include parameters about interchannel intensity difference (IID), interchannel correlation (IC), overall phase difference (OPD), and interchannel phase difference (IPD), which are required to restore the mono audio to the stereo audio.

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 a method and apparatus for encoding/decoding stereo audio. In the method for encoding stereo audio, stereo audio is encoded based on at least one of the phase difference between first and second channel audios and information on an angle made by a vector on the intensity of mono-audio and a vector on the intensity of the first channel audio or a vector on the intensity of the second channel audio. Thus, the number of encoded parameters is minimized so that a compression ratio in the encoding of the stereo audio is improved.

Abstract: Provided are a method and apparatus for encoding/decoding stereo audio. In the method for encoding stereo audio, stereo audio is encoded based on at least one of the phase difference between first and second channel audios and information on an angle made by a vector on the intensity of mono-audio and a vector on the intensity of the first channel audio or a vector on the intensity of the second channel audio. Thus, the number of encoded parameters is minimized so that a compression ratio in the encoding of the stereo audio is improved.

Abstract: Provided are parametric audio encoding and decoding apparatuses and methods thereof. In the parametric audio encoding method, an audio signal is segmented into a plurality of segments. At least one sine wave is extracted from each of the segments, and the extracted sine waves are connected. It is determined whether an extracted sine wave is a birth sine wave. If the extracted sine wave is a birth sine wave, a bit stream is generated by encoding the phase of the birth sine wave on the basis of the frequency of the birth sine wave, wherein the number of bits allocated to encode the phase of the birth sine wave is adjusted according to the frequency of the birth sine wave.

Abstract: The present invention relate to an aluminum alloy for die-casting. More particularly, the present invention relate to an aluminum alloy being usable for die-casting and including 1.0% to 5.0% by weight of Mn, 0.5% to 1.5% by weight of Zn, 1.0% to 2.0% by weight of Zr, 0.5% to 1.5% by weight of Cu and 85% to 97% by weight of aluminum. Surface smut due from silicon smutting is not caused after a molding process so that a product can have a clear color. Furthermore, the aluminum alloy can increase an adhesion strength of a coating layer thereby increasing a durability of a die-casting product. Furthermore, because the aluminum alloy does not include a heavy metal harmful to human being, the aluminum alloy may be non-toxic and environment-friendly.

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.

Abstract: Provided is a multi-channel audio decoding method and apparatus therefor, the method involving decoding filter bank coefficients of a plurality of bands from a bitstream having a predetermined format; performing frequency transformation on the decoded filter bank coefficients of the plurality of bands, with respect to each of the plurality of bands; compensating for a phase of each of the plurality of bands according to a predetermined phase compensation value, and serially band-synthesizing the frequency-transformed coefficients of each of the plurality of phase-compensated bands on a frequency domain; and decoding a multi-channel audio signal from the band-synthesized frequency-transformed coefficients.

Abstract: A method and apparatus for encoding/decoding a media signal. The method of decoding a media signal includes extracting first table index information from a header. The first table index information indicates M (M<N) tables substantially referred to by frames from among N tables which can be referred to for performing an operation performed by the frames, wherein N and M are natural numbers. Second table index information is then extracted from each frame. The second table index information indicates tables referred to by each frame from among M tables. The tables, which are referred to by the frames, are then identified by using the first and second table index information and the frames are decoded by referring to identified tables.

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 encoding a multi-channel 3-dimensional (3D) audio signal mixed with a multi-channel 3D object signal is provided. The method includes: obtaining a location parameter indicating a virtual location of the multi-channel 3D object signal on a multi-channel speaker layout based on a gain value of the multi-channel 3D object signal for each channel; and encoding the multi-channel 3D audio signal and the location parameter.

Abstract: Provided are a method and apparatus for coding and decoding an amplitude of partials, in which a step phenomenon can be prevented in the result of coding the amplitude of continuation partial partials in a parametric codec, thereby improving reproduced sound quality. The method of coding the amplitude of partials includes obtaining an inversely quantized amplitude of partials of a previous frame, determining a quantization level based on a function for the inversely quantized amplitude of the partials of the previous frame, and quantizing an amplitude of partials of a current frame based on the determined quantization level.

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.

Abstract: Provided are a method and apparatus for encoding an audio signal and a method and apparatus for decoding an audio signal. The method includes performing sinusoidal analysis on an audio signal in order to extract a sinusoidal signal of a current frame, determining continuation sinusoidal signal information indicating a number of continuation sinusoidal signals of next frames, which continue from the sinusoidal signal of the current frame, by performing sinusoidal tracking on the extracted sinusoidal signal of the current frame, and encoding the determined continuation sinusoidal signal information by using different Huffman tables according to index information of the current frame, thereby allowing efficient encoding with a low bitrate.

Abstract: An audio signal processing method includes: receiving an audio signal comprising consecutive frames; generating a first encoding parameter corresponding to a first frame among the consecutive frames and a second encoding parameter corresponding to a second frame adjacent to the first frame; and generating at least one interpolated parameter based on the first encoding parameter and the second encoding parameter.

Abstract: A method processing a signal, an encoding apparatus, and a decoding apparatus are provided. The method of processing a signal includes restoring a down-mixed original signal using a re-quantized prediction parameter to generate a restored signal in an encoding apparatus; generating mute information indicating whether the down-mixed original signal has been muted, according to a value of the restored signal; and transmitting the mute information and the down-mixed original signal from the encoding apparatus to a decoding apparatus.

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: Provided are a signal processing method capable of inserting additional information into a bitstream without departing from the AC-3 standard or the Enhanced AC-3 standard. The signal processing method includes: extracting additional information which is for performing at least one of a channel number expansion of an audio signal in an encoding apparatus and a three-dimensional (3D) reproduction of the audio signal in the encoding apparatus; encoding the audio signal according to a predetermined standard; formatting the encoded audio signal into a bitstream including bitstream information, at least one audio block and an auxiliary data field; and inserting the additional information into at least one of additional bitstream information included in the bitstream information, a skip field included in the audio block and auxiliary data bits included in the auxiliary data field.

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 comprising the encoding result of the first encoding operation and the encoding result of the second encoding operation.

Abstract: Provided are a methods and apparatuses for encoding/decoding an audio signal to efficiently encode/decode a harmonic envelope. The method of encoding an audio signal includes performing harmonic analysis with respect to an input signal to determine harmonic parameters with respect to harmonic signals; correlating the amplitudes of the harmonic signals to signals in a time domain instead of signals in a frequency domain; applying a time-frequency transformation operation to the amplitudes in the time domain to generate time-frequency transformed values in the frequency domain; and encoding the time-frequency transformed values. When expressing a harmonic envelope, the amplitudes of the harmonic signals are regarded as signals in the time domain so as to perform a time-frequency transformation and only a part from among the transformed values is selected to be encoded. Therefore, sound quality is not affected and coding efficiency greatly improves.