Sony Corporation

Hitachi, Ltd.

Yuuji Maeda

Jun Matsumoto

Masayuki Nishiguchi

Koji Yamaguchi

Shiro Suzuki

Yuuki Matsumura

Tokihito Suwa

Yasuhiro Toguri

Satoru Shigeta

The present technology relates to an encoder and an encoding method, a decoder and a decoding method, and a program by which encoding efficiency is able to be improved by constraining an appearance probability of a predetermined quantization value of an encoding target to 0 when encoding with a combination of Huffman encoding and multidimensional encoding is performed.

Encoder and encoding method, decoder and decoding method, and program

There is provided an audio encoder comprising a determination part determining, based on frequency spectra of audio signals of a plurality of channels, a mixing ratio as a ratio, relative to a frequency spectrum after mixing for each channel of the plurality of channels, of the frequency spectrum for another channel, a mixing part mixing the frequency spectra of the plurality of channels for each channel based on the mixing ratio determined by the determination part, and an encoding part encoding the frequency spectra of the plurality of channels after mixing by the mixing part.

Audio encoder, audio encoding method and program

There is provided an audio coding device including a first windowing part that multiplies an audio signal by a first window function, a second windowing part that multiplies the audio signal by a second window function having a characteristic different from a characteristic of the first window function, a window selecting part that selects the first window function or the second window function as an optimum window function based on the audio signal multiplied by the first windowing part and the audio signal multiplied by the second windowing part, a coding part that codes a frequency spectrum of the audio signal multiplied by the optimum window function, and a transmitting part that transmits the frequency spectrum coded by the coding part and window function information representing the optimum window function.

Audio coding device and audio coding method, audio decoding device and audio decoding method, and program

A decoding device includes an acquisition unit configured to acquire a first frequency signal including a narrowband signal and a wideband signal, a direct inverse orthogonal transform unit configured to perform a direct matrix operation with respect to the narrowband signal of the first frequency signal so as to perform inverse orthogonal transform, and a high-speed inverse orthogonal transform unit configured to perform inverse orthogonal transform employing a high-speed operation method with respect to the wideband signal of the first frequency signal.

Decoding device, decoding method, and program

The present invention relates to a speech processing apparatus, a speech processing method and a program which, when multichannel audio signals are downmixed and coded, prevent delay and an increase in the computation amount upon decoding of the audio signals. An inverse multiplexing unit () acquires coded data on which a BC parameter is multiplexed. An uncorrelated frequency-time transform unit () performs IMDCT transform and IMDST transform of frequency spectrum coefficients of a monaural signal (X) obtained from this coded data to generate the monaural signal X) which is a time domain signal and a signal (X') which is substantially uncorrelated with this monaural signal (X). The stereo synthesis unit () generates a stereo signal by synthesizing the monaural signal (X) and the signal (X&#x2032;) using the BC parameter. The present invention is applicable to, for example, a speech processing apparatus which decodes a downmixed and coded stereo signal.

Speech processing apparatus, speech processing method and program

The present invention relates to a decoding apparatus, a decoding method, an encoding apparatus, an encoding method, and programs that can shorten the delay time caused by the band extension at the time of decoding, and restrain increases in resources on the decoding side. A higher frequency component generating unit () generates a pseudo higher frequency spectrum by using a lower frequency spectrum (SP-L) and a higher frequency envelope (ENV-H). A phase randomizing unit () randomizes the phase of the pseudo higher frequency spectrum, based on a random flag (RND). An inverse MDCT unit () denormalizes the lower frequency spectrum (SP-L) by using a lower frequency envelope (ENV-L), and combines the pseudo higher frequency spectrum supplied from the phase randomizing unit () with the denormalized lower frequency spectrum (SP-L). The combination result is used as the spectrum of the entire band. The present invention can be applied to a decoding apparatus that performs band extension decoding, for example.

Decoding apparatus and method, encoding apparatus and method, and program

The present invention relates to an encoding device and an encoding method, a decoding device and a decoding method, and a program that reduce deterioration of sound quality due to encoding of audio signals. An envelope emphasis part () emphasizes an envelope (ENV). A noise shaping part () divides an emphasized envelope (D) formed by emphasis of the envelope (ENV) by a value larger than 1, and subtracts noise shaping (G) specified by information (NS) from a result of the division. A quantization part () sets a result of the subtraction as a quantization bit count (WL), and quantizes a normalized spectrum (S) formed by normalization of a spectrum (S) based on the quantization bit count (WL). A multiplexing part () multiplexes the information (NS), a quantized spectrum (QS) formed by quantization of the normalized spectrum (S), and the envelope (ENV). The present invention can be applied to an encoding device encoding audio signals, for example.

Encoding device and encoding method, decoding device and decoding method, and program

A decoding device including a decoding unit which decodes encoded data, an inverse orthogonal transformation unit which performs inverse orthogonal transformation for the encoded data and obtains a time series waveform element in a unit of blocks, a correlation calculation unit which obtains a correlation between a time series waveform element of a block arranged immediately before an error block which is a block in which an error has occurred during decoding by the decoding unit and a time series waveform element of a block arranged a predetermined number of blocks before the block, a cycle calculation unit which obtains a basic cycle of a block unit of the error block based on the correlation obtained by the correlation calculation unit, and a generation unit which generates a substitute signal of the time series waveform element of the error block.

Decoding device, decoding method, and program for generating a substitute signal when an error has occurred during decoding

An encoding apparatus includes a time-frequency transform unit that performs a time-frequency transform on an audio signal, a normalization unit that normalizes a frequency spectral coefficient obtained by the time-frequency transform in order to generate encoded data of the audio signal, a level calculation unit that calculates a level of the audio signal, a scale factor changing unit that changes a concealment scale factor included in encoded concealment data obtained by performing, on the basis of the level of the audio signal, a time-frequency transform and normalization on a minute noise signal, the concealment scale factor being a scale factor relating to a coefficient used for the normalization, and an output unit that outputs the encoded data of the audio signal generated by the normalization unit or outputs, as encoded data of the audio signal, the encoded concealment data whose concealment scale factor has been changed.

Encoding apparatus, encoding method, decoding apparatus, decoding method, and program

Provided is a signal encoding apparatus including: an encoding unit which encodes a quantization value of a frequency spectrum in an input signal through a plurality of encoding algorithms; an amplitude change amount calculation unit which calculates, for each of a plurality of subbands of the frequency spectrum, an amplitude change amount with respect to the frequency spectrum based on a spectrum envelope of the frequency spectrum; and an encoding selection unit which selects, for each subband, the encoding algorithm according to a degree of deflection of an occurrence probability distribution of the quantization value in the amplitude change amount among the plurality of the encoding algorithms.

Signal encoding apparatus, signal decoding apparatus, signal processing system, signal encoding process method, signal decoding process method, and program

Provided is an encoding apparatus including: a determination unit which determines bit allocation at the time of quantizing a data signal based on normalization information of the data signal so that a data length as a result of fixed length encoding of the quantized data signal becomes close to a second data length which is equal to or larger than a first data length allocated to a result of variable length encoding of the quantized data signal; a quantizer which quantizes the data signal based on the bit allocation; and an encoder which performs variable length encoding on the quantized data signal, wherein the determination unit updates the second data length so that a difference between a data length of the variable-length-encoded data signal and the first data length is within a predetermined range.

An encoding apparatus includes a unit that calculates a plurality of normalized values by dividing input values in an input signal by either a normalization coefficient that is closest to a maximum value of absolute values of the input values or a normalization coefficient that is closest to the maximum value from among normalization coefficients that are larger than the maximum value; a unit that generates a plurality of quantized values by quantizing the plurality of normalized values; a unit that stores a code table in which the smaller the probability of occurrence of the plurality of quantized values, the longer the code length of a variable-length code allocated to the plurality of quantized values; and a unit that outputs, when the plurality of quantized values are all zero, a variable-length code allocated to a combination of a plurality of quantized values in accordance with the code table.

Encoding apparatus, decoding apparatus, information processing system, and computer-readable storage medium

A signal processing apparatus includes a decoding unit, an analyzing unit, a synthesizing unit, and a selecting unit. The decoding unit decodes an input encoded audio signal and outputs a playback audio signal. When loss of the encoded audio signal occurs, the analyzing unit analyzes the playback audio signal output before the loss occurs and generates a linear predictive residual signal. The synthesizing unit synthesizes a synthesized audio signal on the basis of the linear predictive residual signal. The selecting unit selects one of the synthesized audio signal and the playback audio signal and outputs the selected audio signal as a continuous output audio signal.

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Tokyo, Japan

Yuuji Maeda