Panasonic Corporation

Kojiro Ono

Takeshi Norimatsu

Shuji Miyasaka

Yoshiaki Takagi

Akihisa Kawamura

Kok Seng Chong

Takashi Katayama

Yosiaki Takagi

Tomokazu Ishikawa

Naoya Tanaka

Mineo Tsushima

Yasuhito Watanabe

An audio decoding device of the present invention includes: a decoding unit decoding a stream to a spectrum coefficient, and outputting stream information when a frame included in the stream cannot be decoded; an orthogonal transformation unit transforming the spectrum coefficient to a time signal; a correction unit generating a correction time signal based on an output waveform within a reference section that is in a section that overlaps between an error frame section to which the stream information is outputted and an adjacent frame section and that is a section in the middle of the adjacent frame section, when the decoding unit outputs the stream information: and an output unit generating the output waveform by synthesizing the correction time signal and the time signal.

Audio decoding device, audio decoding method, program, and integrated circuit

A teleconference terminal apparatus including: an input unit which receives a speech signal; an analyzing unit which calculates a target size on a predetermined segment basis of a speech signal; a coding unit which codes the speech signal to generate a data stream, so that the coded data size on a predetermined segment basis becomes the target size corresponding to each predetermined segment; a stream transmitting unit which transmits to a network the data stream; a receiving unit which receives the data stream transmitted from another terminal apparatus; a filtering unit which determines whether segment data is to be decoded based on data size for each predetermined segment in the received data stream, the segment data being included in the data stream; a decoding unit which decodes segment data determined to be decoded to generate a speech signal; and an output unit which outputs the generated speech signal.

Teleconference terminal apparatus, relaying apparatus, and teleconferencing system

A signal processing device includes a generation unit that generates a second signal from a first signal that is obtained by down mixing two signals; a mixing coefficient determination unit that determines, based on a value L and a value &#x3b8;, a mixing degree for mixing the first signal and the second signal; and a mixing unit that mixes the first signal and the second signal based on the mixing degree determined by the mixing coefficient determination unit. The generation unit includes a first filter that generates a low frequency band signal in the second signal, from a low frequency band signal in the first signal; and a second filter that generates a high frequency band signal in the second signal, from a high frequency band signal in the first signal. The first filter is a filter unit which, for a complex-number signal, de-correlates an input signal and adds a reverberation component by using a delay unit and an all pass filter, and the processing unit is a filter unit different from the first filter.

Signal processing device

Provided is a multi-channel acoustic signal processing device by which loads of arithmetic operations are reduced. The multi-channel acoustic signal processing device includes: a decorrelated signal generation unit, and a matrix operation unit and a third arithmetic unit. The decorrelated signal generation unit generates a decorrelated signal w' indicating a sound which includes a sound indicated by an input signal x and reverberation, by performing reverberation processing on the input signal x. The matrix operation unit and the third arithmetic unit generate audio signals of m channels, by performing arithmetic operation on the input signal x and the decorrelated signal w&#x2032; generated by the decorrelated signal generation unit, using a matrix Rwhich indicates distribution of a signal intensity level and distribution of reverberation.

Multi-channel acoustic signal processing device

Provided is an audio decoder which can reduce an amount of arithmetic operations while suppressing occurrence of aliasing noise. The audio decoder includes: a decoder () and an analysis filter bank () which generate, from a coded down-mixed signal, the first frequency band signal (x) corresponding to a down-mixed signal (M); a channel expansion unit () which converts the first frequency band signal (x) generated by the analysis filter bank () into output signals (y) corresponding to respective audio signals of N channels, using BC information; an synthesis filter bank () which performs band synthesis for the output signals (y) generate by the channel expansion unit () and thereby converts the output signals (y) into the respective audio signals of the N channels on a time axis; and an aliasing noise detection unit () which detects occurrence of aliasing noise in the first frequency band signal (x). The channel expansion unit () further prevents the aliasing noise from being included in the output signals (y), based on information detected by the aliasing noise detection unit ().

Audio decoder

To provide an acoustic signal processing apparatus which can reduce the amount of calculation in matrix arithmetic. An acoustic signal processing apparatus converts down-mixed acoustic signals of NI channels to acoustic signals of NO channels, where NO&#x3e;NI. The acoustic signal processing apparatus includes: a first matrix arithmetic unit for performing arithmetic on a matrix with K rows and NI columns, where NO&#x3e;K&#x2267;NI, for the down-mixed acoustic signals of the NI channels, and outputting K signals obtained after the matrix arithmetic; K decorrelation units for generating signals incoherent, in terms of time characteristics, with the signals obtained after the matrix arithmetic, while maintaining frequency characteristics of the signals obtained after the matrix arithmetic; and a second matrix arithmetic unit for performing arithmetic on a matrix with NO rows and (NI+K) columns for the down-mixed acoustic signals of the NI channels and for the K incoherent signals, and outputting the acoustic signals of the NO channels.

Acoustic signal processing apparatus and acoustic signal processing method

A coding apparatus generates coded data by coding inputted data in a predetermined unit basis, maps one or more units of the coded data onto a packet of fixed length and outputs the packet. The coding apparatus includes a storage unit that stores the coded data and outputs the data size of the stored coded data, and a packetization unit that maps the coded data stored in the storage unit onto the packet and outputs the header size assigned to the one or more units of the coded data and the payload size of the packet. The coding apparatus also includes a control unit that generates the control information based on the data size of the outputted coded data, the header size and the payload size and outputs the control information, and a coding unit that generates the coded data by calculating an outer candidate value that makes the data size of the coded data to be mapped onto the packet an integral multiple of the payload size of the packet based on the outputted control information and coding the predetermined units of inputted data up to the outer candidate value.

Coding method and coding apparatus

A temporal processing apparatus includes: a splitter splitting an audio signal, included in the sub-band domain, into diffuse signals indicating reverberating components and direct signals indicating non-reverberating components; a downmix unit generating a downmix signal by downmixing the direct signals; BPFs respectively generating a bandpass downmix signal and bandpass diffuse signals; normalization processing units respectively generating a normalized downmix signal and normalized diffuse signals; a scale computation processing unit computing, on a predetermined time slot basis, a scale factor indicating the magnitude of energy of the normalized downmix signal with respect to energy of the normalized diffuse signals; a calculating unit generating scale diffuse signals; a HPF generating high-pass diffuse signals; an adding unit generating addition signals; and a synthesis filter bank performing synthesis filter processing on the addition signals and transforming the addition signals into the time domains.

Energy shaping apparatus and energy shaping method

Provided are an audio encoding device and an audio decoding device, by which optimal trade-off between code rates and sound quality can be flexibly adjusted. A variable frequency segmentation encoding unit includes: difference degree calculation units for calculating a difference degree between first and second input signals depending on a segmentation method for segmenting a frequency band into sub-bands; a selection unit for selecting one of the segmentation methods; and a difference degree and segmentation information encoding unit for encoding the selected method and the difference degree for each sub-band. A variable frequency segment decoding unit includes: a segmentation information decoding unit for decoding the segmentation information to learn the segmentation method; a switching unit for outputting a difference degree code corresponding to the segmentation method; and difference degree decoding units for decoding the difference degree code to the difference degree for each sub-band.

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Osaka, Japan

Kojiro Ono