Patent application number | Description | Published |
20080219344 | Encoding device and encoding method - When creating SBR data in a the low-resolution mode, an encoding device divides a high-frequency component of input audio data being encoded by SBR method into a high-frequency band and a low-frequency band, and calculates an average high-frequency power value that indicates the average value of the power in the high-frequency band of the audio data, as well as an average low-frequency power value that indicates the average value of the power in the low-frequency band of the audio data. The encoding device then compares the average high-frequency power value and the average low-frequency power value, selecting the smaller of the two. The encoding device then corrects the power of the high-frequency component of the signal being encoded by the SBR method so that it equals the selected average power value. | 09-11-2008 |
20080288262 | Decoding apparatus and decoding method - A decoding apparatus that decodes a first encoded data that is encoded into a first time range from a low-frequency component of an audio signal, and a second encoded data that is used when creating a high-frequency component of the audio signal from the low-frequency component and encoded into a second time range, into the audio signal. In the decoding apparatus, a high-frequency component compensating unit that compensates the high-frequency component created from the second encoded data based on the first time range. A decoding unit that decodes into the audio signal by synthesizing the high-frequency component compensated by the high-frequency component compensating unit, and the low-frequency component decoded from the first encoded data. | 11-20-2008 |
20090070120 | Audio regeneration method - According to an aspect of an embodiment, a method for regenerating an audio signal including a low frequency component and a high frequency component by decoding a coded data including a first coded data and a second coded data, the method comprising the steps of: generating the low frequency component; generating the high frequency component; determining whether the low frequency component has transient characteristics or not; generating a low frequency correction component by removing a stationary component when the audio signal has the transient characteristics; generating a corrected high frequency component by correcting the high-frequency component on the basis of the duration of the low frequency correction component when the audio signal has the transient characteristics; and regenerating the audio signal by synthesizing the low frequency component with the corrected high-frequency component. | 03-12-2009 |
20090210235 | ENCODING DEVICE, ENCODING METHOD, AND COMPUTER PROGRAM PRODUCT INCLUDING METHODS THEREOF - A disclosed encoding device converts an audio signal into frequency spectra, determines allowable error powers with respect to bands divided by the frequency of the audio signal by a predetermined with, detects a tonal frequency spectrum from the frequency spectra, and detects a band containing the frequency spectrum. Using the detection result and the allowable error powers, the encoding device performs correction such that allowable error powers determined by a power determining unit with respect to bands adjacent to the band detected by a detecting unit become smaller than the powers of the frequency spectra with respect to the adjacent bands, and quantizes each of frequency spectra having greater powers than the corrected allowable error powers. | 08-20-2009 |
20100080397 | AUDIO DECODING METHOD AND APPARATUS - A decoded sound analysis unit ( | 04-01-2010 |
20100106511 | Encoding apparatus and encoding method - An encoding apparatus converts an input signal into a frequency-domain spectrum signal, divides the converted spectrum signal into an arbitrary number of segments with respect to a time axis and a frequency axis, calculates a spectrum power of each segment and a feature parameter that represents a feature of the corresponding spectrum power, calculates a masking threshold using the calculated spectrum power of each segment, detects a segment having a spectrum power equal to or less than the calculated masking threshold, corrects the spectrum power of the detected segment, and encodes both the spectrum power of the corrected segment and the calculated parameter. | 04-29-2010 |
20100153120 | AUDIO DECODING APPARATUS AUDIO DECODING METHOD, AND RECORDING MEDIUM - An audio decoding method includes: acquiring, from encoded audio data, a reception audio signal and first auxiliary decoded audio information; calculating coefficient information from the first auxiliary decoded audio information; generating a decoded output audio signal based on the coefficient information and the reception audio signal; decoding to result in a decoded audio signal based on the first auxiliary decoded audio signal and the reception audio signal; calculating, from the decoded audio signal, second auxiliary decoded audio information corresponding to the first auxiliary decoded audio information; detecting a distortion caused in a decoding operation of the decoded audio signal by comparing the second auxiliary decoded audio information with the first auxiliary decoded audio information; correcting the coefficient information in response to the detected distortion; and supplying the corrected coefficient information as the coefficient information when generating the decoded output audio signal. | 06-17-2010 |
20100169080 | AUDIO ENCODING APPARATUS - An audio encoding apparatus that encodes audio signals of a plurality of channels, includes an adaptive bit allocation control unit that adaptively controls a number of encoding bits assigned to the audio signal of each channel in accordance with perceptual entropy of the audio signal of each of the channels,
| 07-01-2010 |
20100174960 | Decoding apparatus, decoding method, and recording medium - A decoding apparatus includes a unit decoding and inversely quantizing coded data to obtain frequency domain audio signal data, a unit computing from the coded data one of the number of scale bits composed of the number of bits corresponding to the scale value of the coded data and the number of spectrum bits composed of the number of bits corresponding to the spectrum value of the coded data, a unit estimating a quantization error of the frequency domain audio signal data based on one of the number of scale bits and the number of spectrum bits of the coded data, a unit computing a correction amount based on the estimated quantization error and correct the frequency domain audio signal data obtained by the frequency domain data obtaining unit based on the computed correction amount, and a unit converting the corrected frequency domain audio signal data into the audio signal. | 07-08-2010 |
20100228552 | Audio decoding apparatus and audio decoding method - An audio decoding apparatus and method are provided. The audio decoding apparatus includes a spectrum converting part configured to divide the first frequency spectrum in each channel of the first audio signal in a time direction or in a frequency direction to calculate a first signal sequence having the same time resolution and the same frequency resolution in all the channels of the first audio signal, a down-mixing part configured to perform weighted addition on the signals at the same time and within the same frequency band included in the first signal sequence in all the channels to calculate a second signal sequence having channels of a second number different from the first number of channels. | 09-09-2010 |
20100329470 | AUDIO INFORMATION PROCESSING APPARATUS AND METHOD - An audio information processing apparatus and method include dividing an audio signal, determining a time period having a power change ratio of an audio signal larger than a first threshold value as an attack candidate, searching the time period of the attack candidate and a time period immediately before the time period of the attack candidate for an attack starting point, correcting a power of an audio signal included in the time period, and determining whether a power change ratio of the audio signal included in the time period is larger than a second threshold value for attack detection which is larger than the first threshold value. | 12-30-2010 |
20110002393 | AUDIO ENCODING DEVICE, AUDIO ENCODING METHOD, AND VIDEO TRANSMISSION DEVICE - An audio encoding device includes, a time-frequency transform unit that transforms signals of channels included in an audio signal having a first number of channels into frequency signals respectively, a down-mix unit that generates an audio frequency signal having a second number of channels, a low channel encoding unit that generates a low channel audio code by encoding the audio frequency signal, a space information extraction unit that extracts space information representing spatial information of a sound, an importance calculation unit that calculates importance on the basis of the space information, a space information correction unit that corrects the space information, a space information encoding unit that generates a space information code, and a multiplexing unit that generates an encoded audio signal by multiplexing the low channel audio code and the space information code. | 01-06-2011 |
20110178806 | ENCODER, ENCODING SYSTEM, AND ENCODING METHOD - An encoding device includes, an estimation unit to estimate a decoded signal of a plurality of channels based on a down-mix signal obtained by down-mixing an input signal of the plurality of channels, similarity between the channels of the input signal, and an intensity difference between the channels of the input signal; an analysis unit to analyze a phase of the input signal and a phase of the decoded signal; a calculation unit to calculate phase information based on the phase of the input signal and the phase of the decoded signal; and a coding unit to encode the similarity between the channels of the input signal, the intensity difference between the channels of the input signal, and the phase information. | 07-21-2011 |
20110246139 | DOWNMIXING DEVICE AND METHOD - A downmixing device includes: a matrix conversion unit configured to perform a matrix operation for an input signal; a rotation correction unit configured to rotate an output signal of the matrix conversion unit; a spatial information extraction unit configured to extract spatial information from the output signal of the rotation correction unit; and an error calculation unit configured to calculate an error amount of the matrix operation result for the input signal by performing a matrix operation for the output signal of the rotation correction unit and the spatial information extracted by the spatial information extraction unit using a matrix that is inverse to the matrix used for the matrix operation by the matrix conversion unit. | 10-06-2011 |
20120078640 | AUDIO ENCODING DEVICE, AUDIO ENCODING METHOD, AND COMPUTER-READABLE MEDIUM STORING AUDIO-ENCODING COMPUTER PROGRAM - An audio encoding device includes, a time-frequency transformer that transforms signals of channels, a first spatial-information determiner that generates a frequency signal of a third channel, a second spatial-information determiner that generates a frequency signal of the third channel, a similarity calculator that calculates a similarity between the frequency signal of the at least one first channel and the frequency signal of the at least one second channel, a phase-difference calculator that calculates a phase difference between the frequency signal of the at least one first channel and the signal of the at least one second channel, a controller that controls determination of the first spatial information when the similarity and the phase difference satisfy a predetermined determination condition, a channel-signal encoder that encodes the frequency signal of the third channel, and a spatial-information encoder that encodes the first spatial information or the second spatial information. | 03-29-2012 |
20120136657 | AUDIO CODING DEVICE, METHOD, AND COMPUTER-READABLE RECORDING MEDIUM STORING PROGRAM - An audio coding device includes a time-to-frequency converter that performs time-to-frequency conversion on each frame of a signal in at least one channel included in an audio signal in a predetermined length of time in order to convert the signal in the at least one channel to a frequency signal; a complexity calculator that calculates complexity of the frequency signal for each of the at least one channel. The audio further includes a bit allocation controller that determines a number of bits to be allocated to each of at least one channel so that more bits are allocated to the each of the at least one channel as the complexity of the each of at least one channel increases, and increases the number of bits to be allocated as an estimation error in the number; and a coder that codes the frequency signal. | 05-31-2012 |
20120163608 | ENCODER, ENCODING METHOD, AND COMPUTER-READABLE RECORDING MEDIUM STORING ENCODING PROGRAM - An encoder includes, a degree-of-importance calculating unit that calculates a degree of importance of each of a first number of signals included in input signals; a signal converting unit that converts the first number of signals included in the input signals into a second number of signals; a degree-of-importance converting unit that converts a first number of degrees of importance, a number of which is equal to the first number of signals, calculated by the degree-of-importance calculating unit into a second number of degrees of importance, a number of which is equal to the second number of signals; a number-of-bits determining unit that determines a number of bits for use in quantizing each of the second number of signals obtained by the conversion performed by the signal converting; and a quantizing unit that quantizes each of the second number. | 06-28-2012 |
20120224703 | AUDIO CODING DEVICE, AUDIO CODING METHOD, AND COMPUTER-READABLE RECORDING MEDIUM STORING AUDIO CODING COMPUTER PROGRAM - An audio coding device includes a time frequency transform unit that, with respect to each of a plurality of channels included in an audio signal, generates a time frequency signal indicating frequency components at each time by performing a time frequency transform on a signal of the channel; a transient detection unit that detects a transient with respect to each of the plurality of channels so as to obtain a transient detection time; a transient time correction unit that, when a difference in transient detection times between an early detection channel in which the transient detection time is earliest and a late detection channel that is a channel other than the early detection channel among the plurality of channels is within a range in which the transient; a grid determination unit that, with respect to each of the plurality of channels, and a coding unit that codes. | 09-06-2012 |
20130054253 | AUDIO ENCODING DEVICE, AUDIO ENCODING METHOD, AND COMPUTER-READABLE RECORDING MEDIUM STORING AUDIO ENCODING COMPUTER PROGRAM - An audio encoding device includes a time-frequency converting unit that conducts time-frequency conversion of channel signals included in an audio signal having a plurality of channels in frame units having a certain length of time to convert the channel signals to respective frequency signals; a downmixing unit that generates a main signal representing a major component of a first channel and a second channel among the plurality of channels, and a residual signal that is a component orthogonal to the main signal; a weight determining unit that obtains a decoding value predicted and a decoding value predicted, obtains signal components affecting each other between the first channel and the second channel; a weighting unit that uses the weighting coefficient; a residual signal encoding unit that encodes the weighted residual signal the weighting coefficient; and a main signal encoding unit that encodes the main signal. | 02-28-2013 |
20130156112 | DECODING DEVICE, ENCODING DEVICE, DECODING METHOD, AND ENCODING METHOD - A decoding device to decode a main signal code obtained by encoding low-frequency components of an original signal and to output a lowband main signal for output of a main signal, includes: a processor; and a memory which stores a plurality of instructions, which when executed by the processor, cause the processor to execute, decoding auxiliary information code obtained by encoding auxiliary information, the auxiliary information being for generating, from the lowband main signal, a highband main signal corresponding to high-frequency components of the original signal; decoding residual code obtained by encoding low-frequency components of a residual signal indicating error components produced by encoding of the original signal, and thereby output a lowband residual signal; generating a highband residual signal indicating high-frequency components of the residual signal, based on the lowband residual signal output by the residual decoder and the output auxiliary information; generating an output signal. | 06-20-2013 |
20130156200 | DECODING DEVICE AND DECODING METHOD - A decoding device includes a decoder configured to separate a first signal obtained by performing down-mix on original signals of a plurality of channels, a residual signal representing a component of a difference between the original signals and the first signal, and spatial information representing the relationship among the original signals of the plurality of channels from an input signal which is obtained by multiplexing the first signal, the residual signal, and the spatial information and decode the separated encoded first signal, the encoded residual signal, and the encoded spatial information; a decorrelation signal generation unit configured to generate a decorrelation signal as decorrelation of the first signal decoded by the decoder; a residual signal determination unit configured to determine whether a level of the residual signal decoded by the decoder is equal to or smaller than a predetermined residual threshold value; a second-signal generation unit. | 06-20-2013 |
20130182854 | AUDIO CODING DEVICE AND METHOD - An audio coding device that uses a first-channel signal, a second-channel signal, and a plurality of channel prediction coefficients included in a code book, according to which predictive coding is performed on a third-channel signal, the first-channel signal, the second-channel signal, and the third-channel signal being included in a plurality of channels of an audio signal, the device includes, a processor; and a memory which stores a plurality of instructions, which when executed by the processor, cause the processor to execute, determining a distribution of error defined by a difference between the third-channel signal before predictive coding and the third-channel signal after predictive coding as a given curved surface according to the first-channel signal, the second-channel signal, and the third-channel signal before predictive coding; and calculating channel prediction coefficients, included in the code book. | 07-18-2013 |
20130218576 | AUDIO SIGNAL CODING DEVICE AND AUDIO SIGNAL CODING METHOD - An audio signal coding device divides a frequency spectrum obtained from an input digital signal to a plurality of bands, scales and quantizes divided frequency spectra based on a scalefactor of each of the bands and a common scale which is common to the plurality of bands, and codes quantized frequency spectra. The audio signal coding device includes a band number determination unit configured to calculate a number of coding bands for coding the quantized frequency spectra, and a common scale estimation unit configured to estimate the common scale in accordance with the number of coding bands. | 08-22-2013 |
20140006035 | AUDIO ENCODING DEVICE AND AUDIO ENCODING METHOD | 01-02-2014 |
20140029752 | AUDIO DECODING DEVICE AND AUDIO DECODING METHOD - An audio decoding device includes a processor; and a memory which stores a plurality of instructions, which when executed by the processor, cause the processor to execute, decoding, using a first channel signal and a second channel signal included in a plurality of channels of an audio signal having a first frequency range and a second frequency range, a first prediction coefficient of the first frequency range and a second prediction coefficient of the second frequency range, both selected from a code book when prediction-encoding a third channel signal that is not subjected to prediction encoding and that is included in the plurality of channels; decoding a residual signal included in the first frequency range, the residual signal representing an error occurring in prediction encoding; and prediction-decoding the third channel signal subjected to prediction-encoding in the second frequency range from the first channel signal, the second channel signal. | 01-30-2014 |
20140114652 | AUDIO CODING DEVICE, AUDIO CODING METHOD, AND AUDIO CODING AND DECODING SYSTEM - An audio coding device includes a processor; and a memory which stores a plurality of instructions, which when executed by the processor, cause the processor to execute, calculating a frequency spectrum characteristic of an input signal; defining a scale factor that is used to quantize a frequency spectrum converted from the input signal, based on the frequency spectrum characteristic, for each of a plurality of bands; and quantizing the frequency spectrum based on the scale factor. | 04-24-2014 |
20140236603 | AUDIO CODING DEVICE AND METHOD - An audio coding device that performs predictive coding on a third-channel signal included in a plurality of channels in an audio signal according to a first-channel signal and a second-channel signal, which are included in the plurality of channels, and to a plurality of channel prediction coefficients included in a coding book, the device includes a processor; and a memory which stores a plurality of instructions, which when executed by the processor, cause the processor to execute, selecting channel prediction coefficients corresponding to the first-channel signal and the second-channel signal so that an error, which is determined by a difference between the third-channel signal before predictive coding and the third-channel signal after predictive coding, is minimized; and controlling the first-channel signal or the second-channel signal so that the error is further reduced. | 08-21-2014 |