Abstract: A method and apparatus for separating and extracting main sound sources from a mixed musical sound signal are provided. A musical sound source separation apparatus may include an prior information signal compressor to compress an prior information signal including a characteristic of a predetermined sound source, a mixed signal divider to divide a mixed signal including a plurality of sound sources into a plurality of segments, a Nonnegative Matrix Partial Co-Factorization (NMPCF) analyzer to acquire common information shared by the plurality of segments, by applying an NMPCF algorithm to the prior information signal, and a target musical instrument signal separator to separate a target musical instrument signal corresponding to the predetermined sound source from the mixed signal, based on the common information.

Abstract: Provided is an apparatus of separating a musical sound source, which may re-construct mixed signals into target sound sources and other sound sources directly using sound source information performed using a predetermined musical instrument when the sound source information is present, thereby more effectively separating sound sources included in the mixed signal. The apparatus may include a Nonnegative Matrix Partial Co-Factorization (NMPCF) analysis unit to perform an NMPCF analysis on a mixed signal and a predetermined sound source signal using a sound source separation model, and to obtain a plurality of entity matrices based on the analysis result, and a target instrument signal separating unit to separate, from the mixed signal, a target instrument signal corresponding to the predetermined sound source signal by calculating an inner product between the plurality of entity matrices.

Abstract: A method and apparatus for separating and extracting main sound sources from a mixed musical sound signal are provided. A musical sound source separation apparatus may include an prior information signal compressor to compress an prior information signal including a characteristic of a predetermined sound source, a mixed signal divider to divide a mixed signal including a plurality of sound sources into a plurality of segments, a Nonnegative Matrix Partial Co-Factorization (NMPCF) analyzer to acquire common information shared by the plurality of segments, by applying an NMPCF algorithm to the prior information signal, and a target musical instrument signal separator to separate a target musical instrument signal corresponding to the predetermined sound source from the mixed signal, based on the common information.

Abstract: An apparatus and method for deciding an adaptive noise level for bandwidth extension are provided. The apparatus includes a noise level decider for deciding a high-band noise level for bandwidth extension according to tonality of an input signal, a pitch frequency analyzer for detecting a pitch frequency of the input signal and analyzing correlation between the detected pitch frequency and a frequency channel, and a noise level controller for adaptively controlling the decided high-band noise level based on the analyzed correlation of the pitch frequency and the frequency channel.

Abstract: A Unified Speech and Audio Codec (USAC) for adjusting an overlap area of a window based on a transition is provided. To increase an encoding efficiency, encoding may be performed by overlapping relatively long windows. Additionally, when a transition is generated between frames, an overlap area of a window may be reduced based on the transition, thereby preventing a noise from occurring due to the transition.

Abstract: Disclosed are an apparatus and a method for separating sound sources capable of learning distributions of corresponding sound sources based on the assumption that specific sound sources have specific distributions based on interchannel correlation parameter in audio signals providing space perception through a plurality of channels to separate an amount corresponding to energy contribution of the corresponding sound sources from mixture signals. Exemplary embodiments of the present invention can more precisely predict the channel distributions of the specific sound sources included in the input mixture signals and more accurately separate sound sources than a method for separating a sound source based on the channel according to the related art, under conditions that general channel distribution information of the specific sound sources are approximately modeled.

Abstract: A known information compression apparatus and method for reducing a size of known information without missing information required to separate a sound source are provided. The known information compression apparatus may include a segment dividing unit to divide known information including sound source information of each musical instrument into a plurality of segments, and a compressed information generating unit to downmix the segments and to generate compressed information.

Abstract: Disclosed are a method and a system of separating and extracting unified major sound sources from a mixed musical signal. A unified sound source separation system includes a first sound source separation unit to separate a first sound source having unique time-domain and frequency-domain characteristics from a mixed musical signal which includes a plurality of sound sources using time-domain and frequency-domain characteristics, and a second sound source separation unit to separate a second sound source existing in a predetermined stereo sound image position from the mixed musical signal using stereo channel information.

Abstract: Provided are an apparatus and method of separating, from a mixed signal, a sound source generated using a rhythm musical instrument based on characteristics of the rhythm musical instrument repeated in an aspect of time. The apparatus may include a separation unit to separate a plurality of mixed signals into a plurality of segments, a Nonnegative Matrix Partial Co-Factorization (NMPCF) analysis unit to perform an NMPCF analysis on the plurality of segments, and to obtain a plurality of entity matrices based on the analysis result, a target instrument signal separating unit to separate, from the mixed signals, a target instrument signal, by calculating an inner product between the plurality of entity matrices, and a signal association unit to associate the target instrument signals separated from each of the plurality of segments.

Abstract: Disclosed is an LPC residual signal encoding/decoding apparatus of an MDCT based unified voice and audio encoding device. The LPC residual signal encoding apparatus analyzes a property of an input signal, selects an encoding method of an LPC filtered signal, and encode the LPC residual signal based on one of a real filterbank, a complex filterbank, and an algebraic code excited linear prediction (ACELP).

Abstract: An encoding apparatus and a decoding apparatus in a transform between a Modified Discrete Cosine Transform (MDCT)-based coder and a hetero coder are provided. The encoding apparatus may encode additional information to restore an input signal encoded according to the MDCT-based coding scheme, when switching occurs between the MDCT-based coder and the hetero coder. Accordingly, an unnecessary bitstream may be prevented from being generated, and minimum additional information may be encoded.

Abstract: Provided is an encoding apparatus for integrally encoding and decoding a speech signal and a audio signal, and may include: an input signal analyzer to analyze a characteristic of an input signal; a stereo encoder to down mix the input signal to a mono signal when the input signal is a stereo signal, and to extract stereo sound image information; a frequency band expander to expand a frequency band of the input signal; a sampling rate converter to convert a sampling rate; a speech signal encoder to encode the input signal using a speech encoding module when the input signal is a speech characteristics signal; a audio signal encoder to encode the input signal using a audio encoding module when the input signal is a audio characteristic signal; and a bitstream generator to generate a bitstream.

Abstract: Provided are an apparatus and a method for integrally encoding and decoding a speech signal and a audio signal. The encoding apparatus may include: an input signal analyzer to analyze a characteristic of an input signal; a first conversion encoder to convert the input signal to a frequency domain signal, and to encode the input signal when the input signal is a audio characteristic signal; a Linear Predictive Coding (LPC) encoder to perform LPC encoding of the input signal when the input signal is a speech characteristic signal; and a bitstream generator to generate a bitstream using an output signal of the first conversion encoder and an output signal of the LPC encoder.

Abstract: Provided are an apparatus and method for providing an object based audio file, and an apparatus and method for playing back an object based audio file. The object based audio file producing apparatus may include a bitstream generator to generate a bitstream about an object based audio file including a plurality of audio object frames and a file header for an object based audio service; and a bitstream transmitter to transmit the bitstream to the object based audio file playback apparatus. The plurality of audio object frames may include a frame storing a audio source in which all of a plurality of audio frames is mixed and a frame storing each of the audio objects.

Abstract: Provided are an apparatus and method of separating, from a mixed signal, a sound source generated using a rhythm musical instrument based on characteristics of the rhythm musical instrument repeated in an aspect of time. The apparatus may include a separation unit to separate a plurality of mixed signals into a plurality of segments, a Nonnegative Matrix Partial Co-Factorization (NMPCF) analysis unit to perform an NMPCF analysis on the plurality of segments, and to obtain a plurality of entity matrices based on the analysis result, a target instrument signal separating unit to to separate, from the mixed signals, a target instrument signal, by calculating an inner product between the plurality of entity matrices, and a signal association unit to associate the target instrument signals separated from each of the plurality of segments.

Abstract: Provided is an apparatus of separating a musical sound source, which may re-construct mixed signals into target sound sources and other sound sources directly using sound source information performed using a predetermined musical instrument when the sound source information is present, thereby more effectively separating sound sources included in the mixed signal. The apparatus may include a Nonnegative Matrix Partial Co-Factorization (NMPCF) analysis unit to perform an NMPCF analysis on a mixed signal and a predetermined sound source signal using a sound source separation model, and to obtain a plurality of entity matrices based on the analysis result, and a target instrument signal separating unit to separate, from the mixed signal, a target instrument signal corresponding to the predetermined sound source signal by calculating an inner product between the plurality of entity matrices.

Abstract: Provided are a method and apparatus for structuring a bitstream for an object-based audio service, and an apparatus for encoding the bitstream. A method of structuring a bitstream, may include: configuring the bitstream by separating the bitstream into a file header and frames of audio objects that are separated using a sound source separation scheme; and storing, in the file header, reproduction level information of audio objects.

Abstract: Disclosed are an apparatus and a method of providing contents. The apparatus of providing the contents may include a receiving unit to receive, from a contents provider, contents and information about a contents providing location, a local group setting unit to search for at least one cell based on the information about the contents providing location and to set the retrieved cell as a content providing location group of the contents, and a transmitting unit to transmit the contents to the set content providing location group. The object based audio contents may be consecutively replayed based on an identical audio preset.

Abstract: An apparatus and method for deciding an adaptive noise level for bandwidth extension are provided. The apparatus includes a noise level decider for deciding a high-band noise level for bandwidth extension according to tonality of an input signal, a pitch frequency analyzer for detecting a pitch frequency of the input signal and analyzing correlation between the detected pitch frequency and a frequency channel, and a noise level controller for adaptively controlling the decided high-band noise level based on the analyzed correlation of the pitch frequency and the frequency channel.