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公开(公告)号：DE69219718T2
公开(公告)日：1997-10-02
申请号：DE69219718
申请日：1992-03-27
Applicant: SONY CORP
Inventor： TSUTSUI KYOYA , SHIMOYOSHI OSAMU
Abstract: An apparatus for compressing a digital input signal compresses a digital input signal arranged into frames of plural samples. The digital input signal is orthogonally transformed by plural orthogonal transform circuits in blocks derived by dividing the frames by a different divisor in each circuit. The resulting spectral coefficients are quantized using an adaptive number of bits. The output of one orthogonal transform circuit is selected based on the outputs of the orthogonal transform circuits. The digital input signal is divided into plural frequency ranges, and frames are formed in each range. A block length decision circuit determines division of the frames of each range signal into blocks in response to range signal dynamics. The range signals are orthogonally transformed in blocks and the spectral coefficients are quantized. The apparatus also includes a frequency analyzing circuit that derives spectral data points from the input data, and groups them in plural bands. A noise level setting circuit finds the energy in each band and sets a allowable noise level in response to the band energy. A block floating coefficient calculating circuit calculates block floating coefficients based on the maximum spectral data point in each band. A quantizing bit number decision circuit determines the number of bits to use for quantizing in response to the allowable noise level and the block floating coefficients. A quantizing circuit quantizes the spectral data points in response to the quantizing bit number decision circuit.
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公开(公告)号：DK0537361T3
公开(公告)日：1997-06-09
申请号：DK92907630
申请日：1992-03-27
Applicant: SONY CORP
Inventor： TSUTSUI KYOYA , SHIMOYOSHI OSAMU
Abstract: An apparatus for compressing a digital input signal compresses a digital input signal arranged into frames of plural samples. The digital input signal is orthogonally transformed by plural orthogonal transform circuits in blocks derived by dividing the frames by a different divisor in each circuit. The resulting spectral coefficients are quantized using an adaptive number of bits. The output of one orthogonal transform circuit is selected based on the outputs of the orthogonal transform circuits. The digital input signal is divided into plural frequency ranges, and frames are formed in each range. A block length decision circuit determines division of the frames of each range signal into blocks in response to range signal dynamics. The range signals are orthogonally transformed in blocks and the spectral coefficients are quantized. The apparatus also includes a frequency analyzing circuit that derives spectral data points from the input data, and groups them in plural bands. A noise level setting circuit finds the energy in each band and sets a allowable noise level in response to the band energy. A block floating coefficient calculating circuit calculates block floating coefficients based on the maximum spectral data point in each band. A quantizing bit number decision circuit determines the number of bits to use for quantizing in response to the allowable noise level and the block floating coefficients. A quantizing circuit quantizes the spectral data points in response to the quantizing bit number decision circuit.
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公开(公告)号：DE69122306T2
公开(公告)日：1997-03-06
申请号：DE69122306
申请日：1991-05-23
Applicant: SONY CORP
Inventor： AKAGIRI KENZO , TSUTSUI KYOYA , FUJIWARA YOSHIHITO
Abstract: In a digital signal encoding apparatus an input digital signal has its frequency range divided (13) into a number of frequency bands so that the bandwidths will be broader towards the frequency bands of higher frequencies, a first allowable noise level (14 to 18) based on the energies on the band-by-band basis, and a second allowable noise level (51 to 55) based on the energies of the signals temporally adjacent to the signals of the frequency band under consideration, are set, and signal components of each frequency band are quantized with the number of bits corresponding to the level of the difference between an output synthesized from the first and the second noise levels and the energy of each frequency band.
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公开(公告)号：AT143543T
公开(公告)日：1996-10-15
申请号：AT91304699
申请日：1991-05-23
Applicant: SONY CORP
Inventor： AKAGIRI KENZO , TSUTSUI KYOYA , FUJIWARA YOSHIHITO
Abstract: In a digital signal encoding apparatus an input digital signal has its frequency range divided (13) into a number of frequency bands so that the bandwidths will be broader towards the frequency bands of higher frequencies, a first allowable noise level (14 to 18) based on the energies on the band-by-band basis, and a second allowable noise level (51 to 55) based on the energies of the signals temporally adjacent to the signals of the frequency band under consideration, are set, and signal components of each frequency band are quantized with the number of bits corresponding to the level of the difference between an output synthesized from the first and the second noise levels and the energy of each frequency band.
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公开(公告)号：DE69116476D1
公开(公告)日：1996-02-29
申请号：DE69116476
申请日：1991-08-22
Applicant: SONY CORP
Inventor： AKAGIRI KENZO , TSUTSUI KYOYA
Abstract: In a digital signal encoder for analyzing an input digital signal by frequency analysis means (10) of the non-block type and frequency analysis means (20, 40, 60) of the block type to quantize outputs obtained, a quantization characteristic (29, 49, 69) is set in the basis of an allowable noise level based on an energy within a predetermined time period of an output from the block type frequency analysis means (10) and an allowable noise level based on an energy of at least one of data preceding and succeeding in time within the predetermined time period, thereby to provide a real time processing.
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Patent Agency Ranking
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公开(公告)号：AU6816794A
公开(公告)日：1994-12-20
申请号：AU6816794
申请日：1994-05-31
Applicant: SONY CORP
Inventor： TSUTSUI KYOYA , HEDDLE ROBERT
Abstract: This method comprises the steps of converting the inputted acoustic signals into the frequency component; separating the output of conversion means to the tone component and the other component (noise component); coding the tone component; coding the noise component; and generating the code string from the output of the coding step.
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公开(公告)号：HU9203758D0
公开(公告)日：1993-04-28
申请号：HU9203758
申请日：1992-03-27
Applicant: SONY CORP
Inventor： TSUTSUI KYOYA , SHIMOYOSHI OSAMU
Abstract: An apparatus for compressing a digital input signal compresses a digital input signal arranged into frames of plural samples. The digital input signal is orthogonally transformed by plural orthogonal transform circuits in blocks derived by dividing the frames by a different divisor in each circuit. The resulting spectral coefficients are quantized using an adaptive number of bits. The output of one orthogonal transform circuit is selected based on the outputs of the orthogonal transform circuits. The digital input signal is divided into plural frequency ranges, and frames are formed in each range. A block length decision circuit determines division of the frames of each range signal into blocks in response to range signal dynamics. The range signals are orthogonally transformed in blocks and the spectral coefficients are quantized. The apparatus also includes a frequency analyzing circuit that derives spectral data points from the input data, and groups them in plural bands. A noise level setting circuit finds the energy in each band and sets a allowable noise level in response to the band energy. A block floating coefficient calculating circuit calculates block floating coefficients based on the maximum spectral data point in each band. A quantizing bit number decision circuit determines the number of bits to use for quantizing in response to the allowable noise level and the block floating coefficients. A quantizing circuit quantizes the spectral data points in response to the quantizing bit number decision circuit.
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公开(公告)号：DE4221321A1
公开(公告)日：1993-02-25
申请号：DE4221321
申请日：1992-06-29
Applicant: SONY CORP
Inventor： AKAGIRI KENZO , OIKAWA YOSHIAKI , TSUTSUI KYOYA
IPC: G11B20/00 , G11B20/10 , G11B27/031 , G11B27/30 , G11B27/34
Abstract: Data recorded with bit compression at a constant bit rate on a magneto-optical disc (1) are reproduced and transmitted to an excess bit removal circuit (84) without an expanding operation, so that at least some bits which will give a quantization noise level imperceptible to human ears are removed by bit compression in relatively small blocks resulting from division along both the time axis and the frequency axis before recording the data on an IC card (2). By removing at least a part of the portions of the bit-compressed data which are not heard by human ears, the quantity of data recorded on the IC card (2) may be reduced further. Moreover, high speed dubbing can be achieved because data are transferred in the compressed state. The bit rate of the data bit-compressed by the bit removal is a variable bit rate, Fig. 2, (not shown).
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公开(公告)号：CA2049786A1
公开(公告)日：1992-02-25
申请号：CA2049786
申请日：1991-08-23
Applicant: SONY CORP
Inventor： AKAGIRI KENZO , TSUTSUI KYOYA
Abstract: An apparatus for encoding an input digital signal divides the input digital signal to produce frequency components of increasing bandwidth as the frequency increases, performs blocking on each of the frequency components to produce blocks of decreasing time length as the frequency increases, performs a fast Fourier transformation on each block and quantizes each block using a quantization characteristic set in accordance with a comparison of the energy of each frequency component in each block with a masking spectrum. The masking spectrum includes both a masking effect on the frequency base of the input signal and masking effect on the time base of the input signal and may further include effects of the minimum audible curve of the human hearing sense characteristic. Utilization of both the temporal and frequency masking effects permits reduction in the bit rate of the encoded signal using real time processing and without deterioration in sound quality.
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