JPH11330973A - Encoding method and device, decoding method and device, digital signal recording method and device, recording medium and digital signal transmitting method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To filter signals in a time domain obtained by decoding signals encoded with high efficiency in a small-scale filtering process and in a simple constitution by adding or subtracting a desired value to/from normalization information in each two-dimensional block and filtering the digital signals. SOLUTION: A high efficiency encoding device divides input digital signals received from an input terminals 100 into prescribed plural frequency bands by band dividing filters 101 and 102, and also performs orthogonal conversion for each frequency band by orthogonal conversion circuits 103 to 105 to obtain spectrum data on the frequency axes. These spectrum data are encoded with adaptive bit allocation by adaptive bit allocation encoding circuits 106 to 108 in each so-called critical band width and in consideration of the human aural characteristics in a low frequency area, and at each band defined by fractionizing the critical band width in consideration of the block floating efficiency in medium and high frequency areas respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an encoding method,
The present invention relates to a decoding method, an encoding device, a decoding device, a digital signal recording method, a digital signal recording device, a recording medium, a digital signal transmission method, and a digital signal transmission device.

[0002]

2. Description of the Related Art There are various conventional methods and apparatuses for highly efficient encoding of audio signals.
Three examples will be described. The audio signal in the time domain is divided into blocks for each unit time, and the signal on the time axis for each block is converted into a signal on the frequency axis (orthogonal transform), divided into a plurality of frequency bands, and encoded for each band. There is a transform coding method which is one of the blocking frequency band division methods. Sub-band coding (SBC: Subband) is one of the non-blocking frequency band division methods in which an audio signal in the time domain is divided into a plurality of frequency bands and encoded without being blocked for each unit time. Coding) There is a method. There is also a high-efficiency coding method that combines the above-described band division coding and transform coding. In this case,
For example, after performing band division by the above-mentioned band division coding method, the signal of each band is orthogonally transformed into a signal in the frequency domain by the above-mentioned transformation coding method, and the code Will be applied.

Here, as a band division filter used in the above-mentioned band division coding system, for example, QMF (Q
There are filters such as uadrature Mirror filter). This filter is a 1976 RECrochiere Di
gital coding of speech insubbands Bell Syst.Tech.
J. Vol.55, No.8, 1976. Also, ICA
SSP 83, BOSTON Polyphase Quadrature filters-A new
The subband codingtechnique Joseph H. Rothweiler has a polyphase quadrature filter (Polyphase Quadrat
ure filters: polyphase quadrature filters, etc. are described.

As the above-mentioned orthogonal transform, for example, an input audio signal is divided into blocks in a predetermined unit time (frame), and a fast Fourier transform (F
FT), a discrete cosine transform (DCT), a modified DCT transform (MDCT), and the like, to transform the time axis to the frequency axis. Regarding the above MDCT, ICASSP 1987 Subband / Transfor
m Coding Using FilterBank Designs Based on Time Do
main Aliasing Cancellation JPPrincen ABBradley
Univ. Of Surrey Royal Melbourne Inst. Of Tech.

[0005] Further, as a frequency division width when quantizing each frequency component divided into frequency bands, there is band division in consideration of human auditory characteristics. That is, an audio signal may be divided into a plurality of bands (for example, 25 bands) with a bandwidth generally called a critical band (critical band) such that the bandwidth becomes wider as the band becomes higher.
Also, when encoding data for each band at this time,
Encoding by predetermined bit allocation for each band or adaptive bit allocation for each band is performed. For example, when encoding the MDCT coefficient data obtained by the above MDCT processing by the above bit allocation, the MDC for each band obtained by the above MDCT processing for each block is used.
Encoding is performed on the T coefficient data with an adaptive number of allocated bits.

[0006] Further, in encoding for each band, a so-called block floating process for realizing more efficient encoding is performed by normalizing and quantizing each band. For example, when encoding the MDCT coefficient data obtained by the above MDCT processing, quantization is performed by performing normalization corresponding to the maximum value of the absolute value of the MDCT coefficient described above for each band. Thus, more efficient encoding is performed. In normalization, numbering corresponding to information of multiple sizes is specified in advance,
This number is used as normalization information. The information on the magnitude of the normalization prepared in advance is numbered at a constant magnitude ratio.

Conventionally, the following two methods are known as the above-mentioned bit allocation method and the device for the same.

[0008] IEEE Transactions of Accoustics, Speec
h, and Signal Processing, vol.ASSP-25, No.4, August 19
In 77, bit allocation is performed based on the magnitude of the signal for each band. Also ICASSP 1980 The critical band
coder--digital encoding of the perceptual requireme
At the nts of the auditory system MA Kransner MIT,
A method of obtaining a required signal-to-noise ratio for each band and performing fixed bit allocation by using auditory masking is described.

A signal which has been subjected to high-efficiency encoding by the above-described method is decoded by the following method. First, a signal subjected to high-efficiency coding is calculated as MDCT coefficient data using bit allocation information, normalization information, and the like for each band. This MDCT coefficient data is subjected to a so-called inverse orthogonal transform, and is converted into data in a time domain. If band division has been performed by a band division filter at the time of encoding, synthesis is further performed using a band synthesis filter. By these operations, the original data in the time domain is decoded.

[0010]

When a signal in the time domain obtained by decoding a signal subjected to the above-described high-efficiency encoding is to be subjected to so-called filter processing, which is a level adjustment for each band, basically, This can be realized by a so-called convolution operation, a combination of a delay circuit and multiplication, etc., on a signal component in the time domain before encoding or a signal component decoded on the time domain.
In this case, a plurality of multipliers, adders, delay circuits, and the like are required, resulting in an increase in the number of processing steps.

Further, the MDCT in the frequency domain after the orthogonal transform is performed.
A method of implementing a filter by adjusting the level using coefficient data is also conceivable.
It becomes necessary to perform multiplication, addition, or subtraction using a multiplier, an adder, or a subtractor for the number of coefficients, resulting in an increase in the number of processing steps.

Further, a signal on which the above-described high-efficiency encoding has been performed is recorded on a certain recording medium, and information in a time domain signal obtained by decoding the recorded signal is changed to a form in which a so-called filtering effect is applied. A similar problem occurs when re-recording is desired. In particular, if you make adjustments in the time domain and try to re-record the results on a recording medium,
It is necessary to perform an inverse orthogonal transform, an orthogonal transform, and the like, and the quality is deteriorated due to an arithmetic error or the like.

[0013] A similar problem occurs in the realization by conversion to the analog domain.

In order to perform effect processing such as bass boost, band pass, and high pass on an audio signal, a special processing IC has conventionally been required.

In order to filter a part of the audio signal, the high-efficiency compression-encoded audio signal is decompressed, and a part of the decompressed audio signal is subjected to a filtering process. Even with compression encoding, it was not feasible.

In view of the above, it is an object of the present invention to realize a filtering process on a signal in the time domain obtained by decoding a signal which has been subjected to high efficiency coding, with a smaller processing step and a simple configuration. Encoding method, decoding method, encoding device, decoding device, digital signal recording method, digital signal recording device, recording medium, digital signal transmission method, and filter method capable of filtering an arbitrary portion of a signal in the time domain. A digital signal transmitting device is proposed.

Another object of the present invention is to record a highly efficient coded signal on a certain recording medium and apply a filter effect to a time domain signal obtained by decoding the recorded signal. When it is desired to change the information in the form and re-record it, it can be realized with a smaller processing step and a simple configuration, and it is possible to perform filtering on an arbitrary portion of the signal in the time domain and to perform an inverse orthogonal transform. , Decoding method, encoding device, decoding device, digital signal recording method, digital signal recording device, recording medium, digital signal transmission method, and digital signal capable of realizing prevention of quality deterioration due to operations such as orthogonal transformation A transmitting device is proposed.

[0018]

According to the encoding method of the present invention, an input digital signal is decomposed into a plurality of frequency band components to obtain signal components in a plurality of two-dimensional blocks relating to time and frequency. For each two-dimensional block, based on the signal components in the two-dimensional block, normalization is performed by selecting, as normalization information, one of several positive values numbered using several bits in advance. The number using the corresponding several bits is used as normalization information, a quantization coefficient representing the characteristic of the signal component in the two-dimensional block is obtained for each two-dimensional block related to time and frequency, and based on the quantization coefficient The bit allocation amount is determined, the signal component in the block is quantized by the normalized data and the bit allocation amount for each two-dimensional block relating to time and frequency, and information is compressed. In an encoding method in which an information compression parameter for each two-dimensional block relating to a wave number is obtained and the number information of valid two-dimensional blocks is selected from a value defined in advance by several bits, at least one two-dimensional block of a plurality of two-dimensional blocks is used. Digital signal filtering is performed by adding or subtracting a desired value for each two-dimensional block with respect to the block normalization information.

According to the present invention, by adding or subtracting a desired value for each two-dimensional block to or from the normalized information of at least one of the two-dimensional blocks, a digital signal is obtained. Performs signal filtering.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first aspect of the present invention is to decompose an input digital signal into a plurality of frequency band components, obtain signal components in a plurality of two-dimensional blocks relating to time and frequency, and obtain two-dimensional components relating to time and frequency. Based on the signal components in the two-dimensional block for each block, normalization is performed by selecting, as normalization information, one of several positive values numbered using several bits in advance, A number using the corresponding bits is used as normalization information, and a quantization coefficient representing the characteristic of a signal component in the two-dimensional block is obtained for each two-dimensional block related to time and frequency, and bit allocation is performed based on the quantization coefficient. The amount is determined, the signal component in the block is quantized by the normalized data and the bit allocation amount for each two-dimensional block related to time and frequency, and information is compressed. Tsu obtain information compression parameter for each click, the encoding method of selecting from predefined values the number information of the two-dimensional blocks are significant for several bits, at least one of the plurality of 2-dimensional blocks of 2
This is an encoding method in which a digital signal is filtered by adding or subtracting a desired value for each two-dimensional block with respect to the normalized information of the dimensional block.

According to a second aspect of the present invention, in the encoding method according to the first aspect of the present invention, a low-pass filter is calculated by calculating normalization information of a two-dimensional block corresponding to a high frequency component among a plurality of frequency band components. This is the encoding method to be realized.

According to a third aspect of the present invention, in the encoding method according to the first aspect of the present invention, normalization information of a two-dimensional block corresponding to a low-frequency component among a plurality of frequency band components is calculated, thereby forming a high-pass filter. This is the encoding method to be realized.

According to a fourth aspect of the present invention, in the encoding method according to the first aspect of the present invention, normalization information of a two-dimensional block corresponding to a band other than a predetermined band among a plurality of frequency band components is calculated to thereby obtain a predetermined value. This is an encoding method that realizes a bandpass filter using a band as a pass band.

According to a fifth aspect of the present invention, an input digital signal is decomposed into a plurality of frequency band components to obtain signal components in a plurality of two-dimensional blocks relating to time and frequency. Based on the signal components in the dimensional block, normalization is performed by selecting one of several positive values that have been numbered using several bits in advance as normalization information, and the corresponding number A number using bits is used as normalization information, a quantization coefficient representing a characteristic of a signal component in the two-dimensional block is obtained for each two-dimensional block regarding time and frequency, and a bit allocation amount is determined based on the quantization coefficient. Quantizing the signal components in the block by the normalized data and the bit allocation amount for each two-dimensional block relating to time and frequency, and compressing the information. The information compression parameter is obtained, the number information of the effective two-dimensional block is selected from a predetermined value of several bits from a predetermined value, and the signal component of each information-compressed two-dimensional block is converted into the time-frequency related two-dimensional block. In a decoding method in which decoding is performed using an information compression parameter for each dimension block, a plurality of 2
This is a decoding method for filtering digital signals by adding or subtracting a desired value for each two-dimensional block to or from the normalized information of at least one of the two-dimensional blocks.

According to a sixth aspect of the present invention, in the decoding method according to the fifth aspect of the present invention, a low-pass filter is formed by calculating normalization information of a two-dimensional block corresponding to a high frequency component among a plurality of frequency band components. This is a decoding method to be realized.

According to a seventh aspect of the present invention, in the decoding method according to the fifth aspect of the present invention, normalization information of a two-dimensional block corresponding to a low-frequency component among a plurality of frequency band components is calculated, so that a high-pass filter is formed. This is a decoding method to be realized.

According to an eighth aspect of the present invention, in the decoding method according to the fifth aspect of the present invention, normalization information of a two-dimensional block corresponding to a band other than the predetermined band among a plurality of frequency band components is calculated. This is a decoding method that realizes a band-pass filter having a band as a pass band.

According to a ninth aspect of the present invention, there is provided a band dividing means for dividing an input digital signal into a plurality of frequency band components, encoding and / or analysis of a plurality of two-dimensional blocks relating to time and frequency by orthogonally transforming the signal. And orthogonal transform means for obtaining signal components for each of the two-dimensional blocks in terms of time and frequency, based on the signal components in the two-dimensional block, and several positive values of several positive numbers that have been numbered in advance using several bits. Normalization is performed by selecting one of them as the normalization information, and a normalized data calculation means for obtaining a number using the corresponding few bits as the normalization information, and two for each two-dimensional block relating to time and frequency. Quantization coefficient calculation means for obtaining quantization coefficients representing characteristics of signal components in a dimensional block; bit allocation calculation means for determining a bit allocation amount based on the quantization coefficients; Compression encoding means for quantizing a signal component in a block with normalized data and a bit allocation amount for each two-dimensional block relating to the number and compressing information, and an information compression parameter for obtaining an information compression parameter for each two-dimensional block relating to time and frequency In an encoding apparatus having a determining unit and an effective two-dimensional block number information determining unit for selecting the number information of two-dimensional blocks to be made valid from a predetermined value with a few bits, at least one of a plurality of two-dimensional blocks is determined. The encoding apparatus includes an arithmetic unit that performs a filtering process by adding or subtracting a desired value for each two-dimensional block with respect to the normalized information of the two-dimensional block.

According to a tenth aspect of the present invention, there is provided band dividing means for dividing an input digital signal into a plurality of frequency band components, and encoding and / or analysis of a plurality of two-dimensional blocks relating to time and frequency by orthogonally transforming the signal. And orthogonal transform means for obtaining signal components for each of the two-dimensional blocks in terms of time and frequency, based on the signal components in the two-dimensional block, and several positive values of several positive numbers that have been numbered in advance using several bits. Normalization is performed by selecting one of them as the normalization information, and a normalized data calculation means for obtaining a number using the corresponding few bits as the normalization information, and two for each two-dimensional block relating to time and frequency. Quantization coefficient calculation means for obtaining a quantization coefficient representing a characteristic of a signal component in the dimensional block; bit allocation calculation means for determining a bit allocation amount based on the quantization coefficient; Compression encoding means for quantizing a signal component in a block with normalized data and a bit allocation amount for each two-dimensional block relating to wave number and compressing information, and an information compression parameter for obtaining an information compression parameter for each two-dimensional block relating to time and frequency Determining means, valid two-dimensional block number information determining means for selecting the number information of the two-dimensional blocks to be valid from a predetermined number of bits, And decoding means for decoding using the information compression parameter for each two-dimensional block relating to time and frequency, wherein the normalized information of at least one two-dimensional block of the plurality of two-dimensional blocks is An operation to add or subtract a desired value for each two-dimensional block and perform filter processing A decoding apparatus having a stage.

According to an eleventh aspect of the present invention, an input digital signal is decomposed into a plurality of frequency band components to obtain signal components in a plurality of two-dimensional blocks relating to time and frequency. Based on the signal components in the dimensional block, normalization is performed by selecting one of several positive values that have been numbered using several bits in advance as normalization information, and the corresponding number A number using bits is used as normalization information, a quantization coefficient representing a characteristic of a signal component in the two-dimensional block is obtained for each two-dimensional block regarding time and frequency, and a bit allocation amount is determined based on the quantization coefficient. , Quantizes the signal components in the block by the normalized data and the bit allocation amount for each two-dimensional block relating to time and frequency, and compresses the information to obtain information relating to each two-dimensional block relating to time and frequency. 2, contraction parameter, and effective
In a digital signal recording method, the number information of a two-dimensional block is recorded on a recording medium together with the number information of the two-dimensional block selected from a predetermined number of bits. This is a digital signal recording method in which a digital signal is filtered by adding or subtracting a desired value for each two-dimensional block.

According to a twelfth aspect of the present invention, in the digital signal recording method according to the eleventh aspect of the present invention, there is provided a digital signal recording method for re-recording filtered normalized information on a recording medium.

According to a thirteenth aspect of the present invention, there is provided band dividing means for dividing an input digital signal into a plurality of frequency band components, and encoding and / or analysis of a plurality of two-dimensional blocks relating to time and frequency by orthogonally transforming the signal. And orthogonal transform means for obtaining a signal component for each of the two-dimensional blocks in terms of time and frequency, based on the signal components in the two-dimensional block, and several positive values numbered in advance using several bits. Normalization is performed by selecting one of them as normalization information, and normalized data calculation means for obtaining a number using the corresponding few bits as normalization information; Quantization coefficient calculation means for obtaining a quantization coefficient representing a characteristic of a signal component in the dimensional block; bit allocation calculation means for determining a bit allocation amount based on the quantization coefficient; Compression encoding means for quantizing signal components in the block by normalized data and bit allocation amount for each two-dimensional block relating to wave number and compressing information, and information compression parameter for obtaining information compression parameter for each two-dimensional block relating to time and frequency Decision means, and effective two-dimensional block number information decision means for selecting the number information of two-dimensional blocks to be validated from a predetermined value with a few bits. In a digital signal recording device in which each output of the number-of-dimensional-blocks information determining means is recorded on a recording medium, at least one of a plurality of two-dimensional blocks is recorded.
This is a digital signal recording device having arithmetic means for adding or subtracting a desired value for each two-dimensional block to or from the normalized information of two two-dimensional blocks and performing a filtering process.

According to a fourteenth aspect of the present invention, in the digital signal recording apparatus of the thirteenth aspect of the present invention, the normalized information filtered by the arithmetic means is re-recorded on a recording medium.

According to a fifteenth aspect of the present invention, an input digital signal is decomposed into a plurality of frequency band components to obtain signal components in a plurality of two-dimensional blocks relating to time and frequency. Based on the signal components in the dimensional block, normalization is performed by selecting one of several positive values that have been numbered using several bits in advance as normalization information, and the corresponding number A number using bits is used as normalization information, a quantization coefficient representing a characteristic of a signal component in the two-dimensional block is obtained for each two-dimensional block regarding time and frequency, and a bit allocation amount is determined based on the quantization coefficient. , Quantizes the signal components in the block by the normalized data and the bit allocation amount for each two-dimensional block relating to time and frequency, and compresses the information to obtain information relating to each two-dimensional block relating to time and frequency. 2, contraction parameter, and effective
In a recording medium in which the number information of the two-dimensional block is recorded together with the number information of the two-dimensional block selected from a predetermined number of bits, at least one of a plurality of two-dimensional blocks is recorded.
By adding or subtracting a desired value for each two-dimensional block from the normalization information of the dimensional block, the digital signal is filtered, and the normalized information after the filter processing is recorded. Recording medium.

According to a sixteenth aspect of the present invention, an input digital signal is decomposed into a plurality of frequency band components to obtain signal components in a plurality of two-dimensional blocks relating to time and frequency. Based on the signal components in the dimensional block, normalization is performed by selecting one of several positive values that have been numbered using several bits in advance as normalization information, and the corresponding number A number using bits is used as normalization information, a quantization coefficient representing a characteristic of a signal component in the two-dimensional block is obtained for each two-dimensional block regarding time and frequency, and a bit allocation amount is determined based on the quantization coefficient. , Quantizes the signal components in the block by the normalized data and the bit allocation amount for each two-dimensional block relating to time and frequency, and compresses the information to obtain information relating to each two-dimensional block relating to time and frequency. 2, contraction parameter, and effective
In the digital signal transmission method for transmitting the number information of the two-dimensional blocks together with the number information of the two-dimensional blocks selected from a predetermined value of several bits, each of the normalized information of at least one of the two-dimensional blocks is compared with two-dimensional blocks.
This is a digital signal transmission method in which a digital signal is filtered by adding or subtracting a desired value for each dimension block, and the digital signal after the filtering is transmitted.

According to a seventeenth aspect of the present invention, there is provided band dividing means for dividing an input digital signal into a plurality of frequency band components, encoding and / or analysis of a plurality of two-dimensional blocks relating to time and frequency by orthogonally transforming the signal. And orthogonal transform means for obtaining a signal component for each of the two-dimensional blocks in terms of time and frequency, based on the signal components in the two-dimensional block, and several positive values numbered in advance using several bits. Normalization is performed by selecting one of them as normalization information, and normalized data calculation means for obtaining a number using the corresponding few bits as normalization information; Quantization coefficient calculation means for obtaining a quantization coefficient representing a characteristic of a signal component in the dimensional block; bit allocation calculation means for determining a bit allocation amount based on the quantization coefficient; Compression encoding means for quantizing a signal component in a block with normalized data and a bit allocation amount for each two-dimensional block relating to wave number and compressing information, and an information compression parameter for obtaining an information compression parameter for each two-dimensional block relating to time and frequency Decision means, and effective two-dimensional block number information decision means for selecting the number information of two-dimensional blocks to be validated from a predetermined value with a few bits. In the digital signal transmitting apparatus for transmitting each output of the number-of-dimensional-blocks information determining means, a desired value is set for each of the two-dimensional blocks with respect to the normalized information of at least one of the two-dimensional blocks. An arithmetic means for performing filter processing by adding or subtracting, and a digit after performing the filter processing. A digital signal transmitting apparatus and a transmitting means for transmitting the Le signal.

[Specific Example of Embodiment] Hereinafter, a specific example of an embodiment of the present invention will be described with reference to the drawings.

In a specific example of this embodiment, an input digital signal such as an audio PCM signal is subjected to band division coding (SBC), adaptive conversion coding (ATC).
form coding) and adaptive bit allocation techniques. This technique will be described with reference to FIG.

In the specific high-efficiency coding apparatus shown in FIG. 1, the input digital signal is divided into a plurality of frequency bands, and orthogonal transform is performed for each frequency band. In the low band, adaptively, for each so-called critical bandwidth (critical band) in consideration of human hearing characteristics described later, and in the middle and high bands, each band in which the critical bandwidth is subdivided in consideration of the block flow efficiency. Are assigned to bits and encoded. Usually, this block is a quantization noise generating block. Further, in a specific example of the embodiment of the present invention, the block size (block length) is adaptively changed according to the input signal before the orthogonal transform.

That is, in FIG. 1, when the sampling frequency is 44.1 kHz, for example,
An audio PCM signal of 22 kHz is supplied.
This input signal is reduced to 0 by a band division filter 101 such as a so-called QMF filter (right angle mirror filter).
１１11 kHz band and 11 kHz to 22 kHz band, and signals in the 0 to 11 kHz band
The band division filter 102 such as an MF filter
It is divided into a 5.5 kHz band and a 5.5 kHz to 11 kHz band.

11 from the above-mentioned band division filter 101
A signal in the band of 22 kHz to 22 kHz is an MDCT (Modified Discrete Cosine Transform) which is an example of an orthogonal transform circuit.
The signal in the 5.5 kHz to 11 kHz band from the above-described band division filter 102 is sent to the MDCT circuit 104, and the 0 to 5.5 kHz band signal from the above band division filter 102 is sent to the MDCT circuit 105. By being sent, each is subjected to MDCT processing. Each of the MDCT circuits 103, 104, and 105 includes a block determination circuit 109, 110, 111 provided for each band.
The MDCT process is performed based on the block size (block length) (band compression parameter) determined by.

Here, each of the MDCT circuits 103, 104,
FIG. 2 shows a specific example of a standard input signal for a block for each band to be supplied to 105. In the specific example of FIG. 2, each of the three filter output signals has a plurality of orthogonal transform block sizes independently for each band, and the time resolution can be switched according to the time characteristics, frequency distribution, and the like of the signal. . If the signal is quasi-stationary in time, the orthogonal transform block size is 11.6 m
S, that is, when the signal is non-stationary as in the long mode in FIG. 2A, the orthogonal transform block size is further divided into two and four. As in the short mode in FIG.
As shown in the middle mode A of FIG. 2 and the middle mode B of FIG. 2D, a part is divided into 5.8 mS, a part is divided into four, and the time resolution is 2.9 mS, thereby adapting to an actual complicated input signal. It has become. It is obvious that the division of the orthogonal transform block size is more effective if a more complicated division is performed if the scale of the processing device permits. The determination of the block size is determined by the block size determination circuits 109, 110, and 111 in FIG.
03, 104, 105, and bit allocation calculation circuit 118
And output from the output terminals 113, 115 and 117 as block size information of the corresponding block.

Referring again to FIG. 1, each MDCT circuit 10
Spectrum data or MDCT coefficient data on the frequency axis obtained by performing MDCT processing in 3, 104 and 105 (signal components in a two-dimensional block related to time and frequency)
Is that the low band is grouped for each so-called critical band (critical band), and the middle and high band is subdivided into critical bands in consideration of the effectiveness of block floating, and adaptive bit allocation coding circuits 106, 107, 108, And transmitted to the bit assignment calculation circuit 118. The critical band is a frequency band divided in consideration of human auditory characteristics, and has a noise when the pure tone is masked by a narrow band noise of the same strength near the frequency of the pure tone. It is a band. In this critical band (critical band), the higher the band, the wider the bandwidth,
The entire frequency band of 0 to 22 kHz described above is divided into, for example, 25 critical bands. The bit allocation calculation circuit 118 in FIG. 1 performs the above-mentioned critical band and block floating for each divided band in consideration of the so-called masking effect and the like based on the above-described block size information and spectrum data or MDCT coefficient data. , A masking amount, an energy or a peak value for each of the divided bands, and the number of bits to be allocated (bit allocation amount) is calculated for each band based on the calculation result. , 107, 10
8, to be transmitted. In these adaptive bit allocation coding circuits 106, 107, and 108, each of the spectrum data or the MDCT is determined according to the above-described block size information and the number of bits allocated to each divided band in consideration of the critical band and the block floating. The coefficient data is re-quantized (normalized and quantized). The data encoded in this manner is taken out via the output terminals 112, 114, and 116 in FIG. For the sake of convenience in the following description, each divided band in consideration of the above-described critical band and block floating, which is a unit of bit allocation,
It is described as a unit block.

Next, a specific method of the bit allocation performed by the bit allocation calculating circuit 118 in FIG. 1 will be described. FIG. 3 is a block circuit diagram showing a schematic configuration of one specific example of the bit allocation calculating circuit 118 in FIG. 1 described above. 3, an input terminal 301 is connected to the MDCT circuits 103 and 104 in FIG.
Spectrum data or MDC on the frequency axis from 105
T coefficient and the above-described block determination circuit 1 in FIG.
Block size information from 09, 110 and 111 is supplied. Hereinafter, in the system of the bit allocation calculating circuit 118 shown in FIG.
Processing is performed using constants, weighting functions, and the like that are adapted to the above-described block size information. 3, spectrum data or MDCT coefficients on the frequency axis input from an input terminal 301 are sent to an energy calculating circuit 302, and the energy of each unit block is, for example, the sum of amplitude values in the unit block. It is obtained by calculation and the like. Instead of the energy for each band, a peak value or an average value of the amplitude value may be used. As an output from the energy calculation circuit 302, for example, the spectrum of the sum of each band is shown as SB in FIG. However, in FIG. 4, in order to simplify the illustration, the number of divisions by unit blocks is 12 blocks (B1 to B1).
B12). The energy calculation circuit 30
In 2, it is assumed that a scale factor value which is normalized data (band compression parameter) indicating a block floating state of a unit block is also determined. Specifically, for example, several positive values are prepared in advance as scale factor value candidates, and a minimum value is selected from among them, taking a value equal to or more than the maximum value of the absolute value of the spectral data or MDCT coefficient in the unit block. Is adopted as the scale factor value of the unit block. The scale factor value may be numbered using several bits in a form corresponding to the actual value, and the number may be stored in a ROM or the like (not shown). For the scale factor value corresponding to the number, for example, 2
It is defined to have a value at an interval of dB. Here, as for the scale factor value determined by the above-described method in a certain unit block, the above-mentioned number corresponding to the determined value is used as sub-information indicating the scale factor of the unit block.

Next, in order to consider the influence on the so-called masking of the above-mentioned spectrum SB obtained by the above-described energy calculation circuit 302, a convolution (combo) is performed by multiplying the spectrum SB by a predetermined weighting function and adding the result. (Reuse) processing. Therefore, the output of the energy calculation circuit 302 for each band, that is, each value of the spectrum SB is sent to the convolution filter circuit 303. The convolution filter circuit 303 includes, for example, a plurality of delay elements for sequentially delaying input data, a plurality of multipliers for multiplying outputs from these delay elements by a filter coefficient (weighting function), and a sum of outputs of the respective multipliers. And a sum adder which takes By this convolution processing, the sum of the parts indicated by the dotted lines in FIG. 4 is obtained.

Next, the output of the convolution filter circuit 303 is sent to the subtractor 304. The subtractor 304 is
A level α corresponding to an allowable noise level (quantized coefficient) described later in the convolved region is obtained. The level α corresponding to the permissible noise level (permissible noise level) becomes an allowable noise level for each of the critical bands by performing inverse convolution processing as described later. Level. Here, an allowance function (a function expressing a masking level) for obtaining the level α is supplied to the subtractor 304. The level α is controlled by increasing or decreasing the allowable function. The permissible function is supplied from the (n-ai) function generation circuit 305 described below.

That is, the level α corresponding to the allowable noise level can be obtained by the following equation (1), where i is a number sequentially given from the lower band of the critical band.

[0048]

Α = S− (n−ai)

In the equation (1), n and a are constants and a
> 0, S is the intensity of the convolved spectrum,
(N-ai) in the equation (1) is an allowable function. N as an example
= 38, a = 1 can be used.

In this way, the above-mentioned level α is obtained, and this data is transmitted to the division circuit 306. The division circuit 306 is for performing inverse convolution of the level α in the convolved region. Therefore, by performing the inverse convolution processing, a masking spectrum can be obtained from the level α. That is, this masking spectrum becomes an allowable noise spectrum. Although the above-described inverse convolution processing requires a complicated operation, in this specific example, the inverse convolution is performed using a simplified division circuit 306.

Next, the above-mentioned masking spectrum is transmitted to the subtraction circuit 309 via the synthesis circuit 308. Here, the output from the above-described energy detection circuit 302 for each band, that is, the above-described spectrum SB is supplied to the subtraction circuit 309 via the delay circuit 310. Therefore, by performing the subtraction operation of the above-described masking spectrum and the spectrum SB in the subtraction circuit 309, as shown in FIG.
The level below the level indicated by the level of the masking spectrum MS is masked.

By the way, at the time of synthesizing by the synthesizing circuit 308 described above, data indicating a so-called minimum audible curve RC, which is a human auditory characteristic as shown in FIG. The above-mentioned masking spectrum MS can be synthesized. At this minimum audible curve, if the absolute noise level is below this minimum audible curve, the noise will not be heard. This minimum audible curve will be different depending on the reproduction volume at the time of reproduction, for example, even if the coding is the same, but in a realistic digital system, for example, when music is entered into the 16-bit dynamic range, Since there is not much difference, if quantization noise in the most audible frequency band around 4 kHz is not heard, for example, it is considered that quantization noise below the level of the minimum audible curve is not heard in other frequency bands. . Therefore, assuming that the system is used in such a way that noise near the word length of 4 kHz of the system cannot be heard, for example, the minimum audible curve RC and the masking spectrum MS are combined together to obtain an allowable noise level (allowable quantization coefficient). Is obtained, the allowable noise level in this case can be up to the shaded portion in FIG. In this embodiment, the 4 kHz level of the above minimum audible curve is adjusted to the lowest level corresponding to, for example, 20 bits. FIG. 6 also shows the signal spectrum SS.

Thereafter, in the allowable noise correction circuit 311, the allowable noise level in the output from the subtraction circuit 309 is corrected based on, for example, information on the equal loudness curve. Here, the equal loudness curve is a characteristic curve relating to human auditory characteristics. For example, the loudness curve is obtained by calculating the sound pressure of sound at each frequency that sounds as loud as a pure tone of 1 kHz, and is connected by a curve. Also called a sensitivity curve. Further, this equal loudness curve draws substantially the same curve as the minimum audible curve RC shown in FIG. In this equal loudness curve, for example, at around 4 kHz, even if the sound pressure falls by 8 to 10 dB from the place of 1 kHz, it sounds as large as 1 kHz. It doesn't sound the same size. For this reason, it is preferable that noise exceeding the level of the minimum audible curve (allowable noise level) (allowable quantization coefficient) has a frequency characteristic given by a curve corresponding to the equal loudness curve. Recognize. From this, it can be understood that correcting the above-mentioned allowable noise level in consideration of the above-mentioned equal loudness curve is suitable for human auditory characteristics. Through a series of processing up to this point, the allowable noise correction circuit 311 calculates bits to be allocated to each unit block based on various parameters such as the above-described masking and auditory characteristics.

The data output from the allowable noise correction circuit 311 is output from the output terminal 312 as the output of the bit allocation calculation circuit 118 in FIG.

That is, the bit allocation calculation circuit 118 in FIG. 1 uses the system shown in FIG. 3 described above to process data obtained by processing the orthogonal transform output spectrum with sub-information as main information and block data as sub-information. The scale factor indicating the floating state and the word length indicating the word length are obtained. Based on these, the adaptive bit allocation encoding circuits 106, 10 in FIG.
In steps 7 and 108, requantization is actually performed, and encoding is performed in a form conforming to the encoding format.

Here, the normalization information adjustment circuit 119 will be described. As described above, for the scale factor value which is the normalized data (band compression parameter), several positive values are prepared in advance as scale factor value candidates, and the spectrum data or MDCT coefficient in the unit block are prepared from among them. Among the values greater than the maximum value of the absolute value of, the smallest one is adopted as the scale factor value of the unit block.
Numbering is performed using several bits in a form corresponding to the actual value, and the number is used as sub-information indicating the scale factor of the unit block. For the scale factor value corresponding to the number, for example, 2 dB
It is specified to have a value at intervals of. Therefore, for example, by manipulating the number of the sub-information indicating the scale factor, the level of the unit block can be adjusted by 2 dB. The normalization information adjustment circuit 119 is a circuit for designating and outputting a numerical value for performing this level adjustment for each two-dimensional block. Also, 120, 121, 122
Is an adder for adding the numerical value from the normalization information adjusting circuit 119 for each band to the scale factor value of the unit block. If the value output from the normalization information adjustment circuit 119 is a negative number, the adders 120, 121, 1
22 functions as a subtractor. That is, for the block for which level adjustment is to be performed, a value is output from the normalization information adjustment circuit 119 for each two-dimensional block, and only by adding or subtracting to or from the normalization information, 2 dB is independently obtained for each two-dimensional block. Allows for level adjustments.
At this time, the addition and subtraction results are restricted so as to be within the range of the scale factor value defined in the format.

As described above, by performing the level adjustment independently for each two-dimensional block, a so-called filter effect can be realized.

Next, an encoding format of data to be actually encoded will be described with reference to FIG. The numerical value shown on the left side of FIG. 7 represents the number of bytes, and in this embodiment, 212 bytes are used as a unit of one frame.

In the position of 0 byte located at the top in FIG. 7, the block determination circuits 109, 1 in FIG.
The block size information of each band determined in 10 and 111 is recorded.

Information on the number of unit blocks to be recorded is recorded at the next byte position. This is because, for example, the bit allocation becomes 0 and the recording is unnecessary in many cases as it goes to the higher frequency side by a series of bit allocation calculation circuits. A lot of bits are allocated to the middle and low frequencies that have a large effect. In addition, the number of unit blocks in which the bit allocation information is double-written and the number of the unit blocks in which the scale factor information is double-written are recorded at the position of one byte. Double writing is a method for recording the same data as data recorded at a certain byte position in another location for error correction. The more this double-write information is, the higher the error resistance is, but the less this information is, the more bits that can be used for the spectrum data. For each of the above-mentioned bit allocation information and scale factor information, the number of double-written unit blocks is set independently, and the strength against errors and the number of usable bits for spectrum data are adjusted. ing. For each piece of information, the correspondence between the code in the prescribed bit and the number of unit blocks is determined in advance as a format. Specifically, as shown in FIG. 8, three bits out of the eight bits at the position of one byte are used as information of the number of unit blocks to be actually recorded, and two bits out of the remaining five bits are used as bit allocation information. The number of unit blocks for which double writing is performed and the number of unit blocks for which double writing of scale factor information is performed for the remaining three bits are recorded.

At the position from the second byte in FIG. 7, bit allocation information of a unit block is recorded. For recording bit allocation information, for example, 4
Use of bits is defined as a format. As a result, bit allocation information for the number of unit blocks actually recorded in FIG. 7 described above is recorded in order from the 0th unit block.

After the data of the bit allocation information recorded by the above method, the scale factor information of the unit block is recorded. For recording of scale factor information, for example, use of 6 bits for one unit block is defined as a format. This allows
Just like the recording of bit allocation information, the scale factor information is recorded in the order of the unit blocks to be actually recorded in order from the 0th unit block.

After the scale factor information thus recorded, the spectrum data of the unit block is recorded. The spectrum data is also recorded in order from the 0th unit block by the number of unit blocks to be actually recorded. The number of pieces of spectrum data that exist in each unit block is determined in advance by the format, so that it is possible to correspond to the data by the above-described bit allocation information. It should be noted that recording is not performed for a unit block whose bit allocation is 0.

After this spectrum information, the above-mentioned double writing of the scale factor information and the two bits of the bit allocation information are performed.
Write overwriting. With regard to this recording method, only the correspondence of the number corresponds to the double-written information shown in FIG.
Others are the same as the recording of the scale factor information and the bit allocation information described above.

In FIG. 7, the scale factor 2
The overwriting and / or the bit allocation double writing may be stopped, and the portion may be allocated to the spectrum data area.

For the last two bytes, the information of the 0th byte and the information of the 1st byte are respectively stored as shown in FIG.
Overwritten. This double-byte double writing is defined as a format, and the variable writing amount of double writing cannot be set like double writing of scale factor information or double writing of bit allocation information.

That is, the bit allocation calculation circuit 118 shown in FIG. 1 uses the system shown in FIG. 3 described above to process data obtained by processing the orthogonal transform output spectrum with sub-information as main information and block data as sub-information. The scale factor indicating the floating state and the word length indicating the word length are obtained. Based on these, the adaptive bit allocation encoding circuits 106, 10 in FIG.
In steps 7 and 108, requantization is actually performed, and if necessary, the normalization information is adjusted based on the output from the normalization information adjustment circuit 119, and is encoded in a form conforming to the encoding format.

FIG. 9 shows a decoding circuit for decoding again a signal which has been efficiently coded by the system shown in FIG. 1 described above. Quantized MDCT for each band
The coefficients, that is, the output terminals 112, 114, 1 in FIG.
Data equivalent to the 16 output signals is given to the decoding circuit input terminal 908 in FIG. 9 and used block size information (block length) (information compression parameter), that is, the output terminals 113, 115, and 117 in FIG. Is provided to the input terminal 910 in FIG. Adaptive bit allocation decoding circuit 906 in FIG.
Then, the bit allocation is released using the adaptive bit allocation information. Next, an inverse orthogonal transform (IMDCT) circuit 9 in FIG.
In 03, 904, and 905, a signal on the frequency axis is converted to a signal on the time axis. The signals on the time axis of these partial bands are supplied to a band synthesis filter (inverse band splitting filter) (IQMF: inverse right angle mirror filter)) circuit 90 in FIG.
2, 901, it is decoded into a full band signal.

Here, the normalization information adjustment circuit 911 will be described. Basically, the normalization information adjustment circuit 1 in FIG.
The same operation as 19 is performed. That is, it is a circuit that outputs a numerical value for performing level adjustment by adding or subtracting the normalized information for each two-dimensional block. Also, 909
Is an adder for adding the numerical value from the normalization information adjustment circuit 911 to the scale factor value of the unit block. When the numerical value output from the normalization information adjusting circuit 911 is a negative number, the adder 909 acts as a subtractor. That is, for a block whose level is to be adjusted in the same manner as in the case of encoding, a numerical value is output from the normalization information adjustment circuit 911 for each two-dimensional block, and added to the normalization information.
Only by subtraction, it is possible to independently adjust the level by 2 dB for each two-dimensional block. At this time,
The result of the subtraction is restricted so as to be within the range of the scale factor value defined in the format. For the scale factor value whose level has been adjusted by the adder 909, the adaptive bit allocation decoding circuit 9
Since it is used in the decoding process from step 06, it can be used only for adjusting the level of the decoded signal, and for example, the scale factor value is read from the encoded recording medium and adjusted. It is also possible to output the performed scale factor value to 907 and change the scale factor value recorded on the recording medium to the adjusted value. The information on the recording medium can be changed as necessary. This makes it possible to change the level information of the recording medium with a very simple system. Thus 2
By performing level adjustment independently for each dimension block, a so-called filter effect can be realized.

In the above description, an example in which both the encoding circuit and the decoding circuit have the normalization information adjusting circuit has been described.
Even with the decoding circuit alone, the filter effect can be fully utilized.

Hereinafter, several specific examples of applying the filter effect using the normalization information adjustment circuit will be described.

For example, a low-pass filter can be realized by setting the output value from the normalization information adjusting circuit only for the high-frequency block and reducing the normalization information of the high-frequency block. .

For example, conversely, a high-pass filter can be realized by setting the output value from the normalization information adjustment circuit only for low-frequency blocks and reducing the low-frequency normalization information. .

Similarly, it is apparent that effects such as a band-pass filter and a comb filter can be realized within the range of the block.

The output value from the normalization information adjusting circuit is set only for the blocks in the bands other than the predetermined band, and the normalization information of the blocks in the bands other than the predetermined band is reduced, so that the bandpass filter can be used. Can be realized.

Further, by increasing the normalization information based on the output value from the normalization information adjustment circuit, the boost processing can be realized within the range that the block can take.

Also, by changing the frequency, ie, the block to which the filter effect is applied, stepwise using time as a parameter, it is possible to realize a wah effect or the like which is a kind of effect processing used for musical instruments and the like.

Next, the filter will be described with reference to FIGS. 10 and 11, taking a low-pass filter as an example. FIG. 10 shows a state in which normalization is performed for each unit block. That is, a normalization candidate corresponding to the largest spectrum data on the frequency axis or the MDCT coefficient (a signal component in a two-dimensional block related to time and frequency) in the unit block is selected, and the normalization candidate number is set to the unit. It becomes the normalization information of the block. In FIG. 10, the normalization information of the unit block having the block number 0 is 5, the normalization information of the unit block having the first block number is 7, and the normalization information of the unit block having the second block number is 9. Becomes
The normalized information of the unit block having the third block number is 6, and the normalized information of the unit block having the fourth block number is 4. Since the encoded data has these pieces of normalization information, decoding is generally performed based on these pieces of normalization information.

On the other hand, FIG. 11 shows spectrum data on the maximum frequency axis in the unit block or MDCT.
The figure shows a state where the normalization information determined based on the coefficient is intentionally operated. This can be performed either at the time of encoding or at the time of decoding. However, here, an example will be described in which the operation is performed intentionally when decoding the encoded data recorded on the recording medium. The encoded data actually recorded on the recording medium is as shown in FIG. 10. For the encoded data, the normalization information is forcibly set to 0 for the unit blocks having the block numbers 3 and 4. I have to. This is realized, for example, by adding a negative value to the normalization information before performing decoding. By performing this operation, the unit blocks having the block numbers 3 and 4 are decoded as being normalized by the normalization candidate number 0. As a result, the unit blocks with block numbers 3 and 4 are decoded on the basis of the lowest-level normalization candidate number 0, so that the spectrum data on the frequency axis or the MDCT coefficient is set to a low level. Decrypted. Assuming that a higher unit block number includes a higher frequency component, this operation corresponds to cutting the level of the higher frequency component. That is, the low-pass filter is realized by intentionally setting the normalized information of the unit block numbers 3 and 4 to 0.

In the examples shown in FIGS. 10 and 11, the number of unit blocks is set to 5 (0, 1 to 4) and the number of normalization candidate numbers is set to 10 (0, 1 to 9). In the format used for the disk, the number of unit blocks is 52, 0, 1 to 51, and the number of normalization candidate numbers is 64, 0, 1 to 63, so that finer control is possible. . At this time, for example, by setting the normalized information of the 20th and subsequent unit blocks to 0, a low-pass filter having a cutoff frequency of about 5.5 kHz can be realized.

Next, referring to FIGS. 12 to 15, a digital signal recording device (method), digital signal reproducing device (method), and digital signal transmitting device (method) including the above-described normalized information adjusting circuit of the present invention. ) And a digital signal receiving apparatus (method) will be described. 12 to 15, ENC indicates the encoder of FIG. 1, Tin indicates its input terminal 100, DEC indicates the decoder of FIG. 9, and Tout indicates its output terminal 900.

In the recording apparatus of FIG. 12, an input digital signal from the input terminal Tin is supplied to the encoder ENC for encoding, and the output of the encoder ENC, that is, FIG.
Output terminals 112, 114, 116 and 1 of the encoders
13, 115, 117 are output from the modulating means MO.
D, and then multiplexes and performs a predetermined modulation, or modulates each output signal and then multiplexes or remodulates.
The modulated signal from the modulating means MOD is recorded on the recording medium M by the recording means (magnetic head, optical head, etc.).

In the reproducing apparatus shown in FIG. 13, the recording medium M shown in FIG.
And the demodulation means DEM demodulates the reproduction signal according to the modulation by the modulation means MOD. A signal corresponding to the demodulated output from the demodulating means DEM, that is, a signal corresponding to the output from the output terminals 112, 114, and 116 of the encoder of FIG. 1 is supplied to the input terminal 908 of the decoder of FIG. 113, 11
Signals corresponding to the outputs from 5, 117 are supplied to an input terminal 910 in FIG. 9 and decoded, and an output digital signal corresponding to the input digital signal is output to an output terminal Tout.

In the transmitting apparatus shown in FIG. 14, the input digital signal from the input terminal Tin is supplied to the encoder ENC and encoded, and the output of the encoder ENC, that is, FIG.
Output terminals 112, 114, 116 and 1 of the encoders
13, 115 and 117 are connected to the modulating means MO.
D, and then multiplexes and performs a predetermined modulation, or modulates each output signal and then multiplexes or remodulates.
The modulated signal from the modulating means MOD is supplied to the transmitting means TX to perform frequency conversion, amplification, etc., thereby producing a transmission signal.
The transmission signal is transmitted by a transmission antenna ANT-T which is a part of the transmission means TX.

In the receiving apparatus shown in FIG. 15, the receiving signal from the transmitting antenna ANT-T shown in FIG. 11 is received by the receiving antenna ANT-R which is a part of the receiving means RX, and the received signal is received by the receiving means RX. , Amplification, inverse frequency conversion, and the like. The demodulation unit DEM demodulates the received signal from the reception unit RX according to the modulation by the modulation unit MOD. The demodulated output from the demodulating means DEM, that is, the output terminals 112, 114, and 11 of the encoder of FIG.
6 is supplied to the input terminal 908 of the decoder in FIG. 9 and the signal corresponding to the output from the output terminals 113, 115, and 117 of the encoder in FIG. 1 is supplied to the input terminal 910 in FIG. The output digital signal corresponding to the input digital signal is output to the output terminal Tout.

The present invention is not limited to the above-described embodiment, and various modifications and changes can be made. The encoder and the decoder may be separate or integrated. The recording device and the reproducing device may be separate or integrated. The recording medium is a magnetic tape. Magnetic disks, magneto-optical disks and the like are possible. Further, instead of the recording medium, a storage means such as an IC memory or a memory card may be used. The transmission path between the transmitting device and the receiving device is a wireless transmission path {radio waves, light (infrared rays, etc.), etc.}.
However, a wired transmission path (a conducting wire, an optical cable, or the like) may be used. For example, as an input digital signal, a digital audio signal (an audio signal can be a signal of various sounds such as a human voice, a singing voice, and a musical instrument), a digital video signal, and the like can be used. The present invention can be applied to a digital signal recording / reproducing method (or device), a digital signal transmitting / receiving method (or device), a digital signal receiving method (or device), and the like.

[0087]

According to the first aspect of the present invention, an input digital signal is decomposed into a plurality of frequency band components to obtain signal components in a plurality of two-dimensional blocks relating to time and frequency, and two-dimensional components relating to time and frequency are obtained. Based on the signal components in the two-dimensional block for each block, normalization is performed by selecting one of several positive values that have been numbered using several bits in advance as normalization information, The number using the corresponding few bits is used as normalization information, and a quantization coefficient representing the characteristic of the signal component in the two-dimensional block is obtained for each two-dimensional block relating to time and frequency, and bit allocation is performed based on the quantization coefficient. The amount is determined, the signal components in the block are quantized by the normalized data and the bit allocation amount for each two-dimensional block relating to time and frequency, and information is compressed. Tsu obtain information compression parameter for each click, the encoding method of selecting from predefined values the number information of the two-dimensional blocks are significant for several bits, at least one of the plurality of 2-dimensional blocks of 2
Digital signal filtering is performed by adding or subtracting a desired value for each two-dimensional block with respect to the normalized information of the two-dimensional block, so that the time at which the highly efficient coded signal is decoded is calculated. It is possible to realize a filtering process for a signal in a region with a smaller processing step and a simple configuration, and it is possible to perform a filtering process for an arbitrary portion of a signal in a time region. The recorded signal is recorded, and the signal in the time domain obtained by decoding the recorded signal is changed to a form in which a filter effect is applied. It is possible to filter any part of the signal in the time domain, and at the same time, degrade the quality due to operations such as inverse orthogonal transform and orthogonal transform. Encoding method capable of realizing the prevention can be obtained.

According to the second aspect of the present invention, in the encoding method according to the first aspect of the present invention, normalization information of a two-dimensional block corresponding to a high-frequency component among a plurality of frequency band components is calculated, thereby providing a low-pass filter. Is realized, and in addition to the effect of the first aspect of the present invention, it is possible to obtain an encoding method capable of performing low-pass filtering.

According to the third aspect of the present invention, in the encoding method according to the first aspect of the present invention, of the plurality of frequency band components,
Since the high-pass filter is realized by calculating the normalization information of the two-dimensional block corresponding to the low-frequency component, an encoding method capable of performing the high-pass filter processing is obtained in addition to the effect of the first aspect of the present invention. be able to.

According to the fourth invention, in the encoding method according to the first invention, among the plurality of frequency band components,
By calculating normalization information of a two-dimensional block corresponding to a band other than the predetermined band, a band-pass filter having a predetermined band as a pass band is realized. An encoding method capable of performing band-pass filtering can be obtained.

According to the fifth aspect of the present invention, the input digital signal is decomposed into a plurality of frequency band components to obtain signal components in a plurality of two-dimensional blocks relating to time and frequency. Then, based on the signal components in the two-dimensional block, normalization is performed by selecting, as normalization information, one of several positive values that have been numbered using several bits in advance. The number using several bits to be used as normalization information, a quantization coefficient representing the characteristic of the signal component in the two-dimensional block is obtained for each two-dimensional block relating to time and frequency, and the bit allocation amount is determined based on the quantization coefficient. Is determined, the signal components in the block are quantized by the normalized data and the bit allocation amount for each two-dimensional block related to time and frequency, and information is compressed. The information compression parameter of each block is obtained, and the number information of the two-dimensional block to be effective is selected from a predetermined value of several bits. In a decoding method in which decoding is performed using an information compression parameter for each two-dimensional block related to frequency,
A digital signal filtering process is performed by adding or subtracting a desired value for each two-dimensional block to or from the normalized information of at least one of the two-dimensional blocks. Therefore, it is possible to realize a filtering process on a signal in the time domain obtained by decoding a signal subjected to high-efficiency coding with a smaller processing step and a simple configuration. Enables filter processing, records a signal with high efficiency encoding on a recording medium, and changes the information in a time domain signal obtained by decoding the recorded signal to a form in which a filter effect is applied. When re-recording is desired, it can be realized with smaller processing steps and a simple configuration, and it is possible to filter any part of the signal in that time domain With there can be obtained a decoding method which can realize the prevention of inverse orthogonal transform, quality deterioration due to the operation of the orthogonal transform or the like.

According to the sixth aspect of the present invention, in the decoding method according to the fifth aspect of the present invention, normalization information of a two-dimensional block corresponding to a high-frequency component among a plurality of frequency band components is calculated, thereby providing a low-pass filter. So that
In addition to the effects of the fifth aspect of the present invention, a decoding method capable of performing low-pass filtering can be obtained.

According to the seventh aspect of the present invention, in the decoding method according to the fifth aspect of the present invention, normalization information of a two-dimensional block corresponding to a low-frequency component among a plurality of frequency band components is calculated, whereby a high-pass Since the filter is realized, a decoding method capable of high-pass filtering can be obtained in addition to the effect of the fifth aspect of the present invention.

According to the eighth aspect of the present invention, in the decoding method according to the fifth aspect of the present invention, normalization information of a two-dimensional block corresponding to a band other than the predetermined band among a plurality of frequency band components is calculated. Since a bandpass filter having a predetermined band as a passband is realized, a decoding method capable of performing bandpass processing can be obtained in addition to the effect of the fifth invention.

According to the ninth aspect of the present invention, there is provided band dividing means for dividing an input digital signal into a plurality of frequency band components,
Orthogonal transformation means for orthogonally transforming a signal to obtain signal components for encoding and / or analysis in a plurality of two-dimensional blocks related to time and frequency, and a signal in the two-dimensional block for each two-dimensional block related to time and frequency Based on the components, normalization is performed by selecting one of several positive values that have been numbered using several bits in advance as normalization information, and the number using the corresponding several bits , As quantization information, and quantization coefficient calculation means for obtaining, for each two-dimensional block relating to time and frequency, a quantization coefficient representing a characteristic of a signal component in the two-dimensional block.
Bit allocation calculating means for determining a bit allocation amount based on the quantized coefficient, and a compression code for quantizing signal components in the block by using normalized data and the bit allocation amount for each two-dimensional block relating to time and frequency and compressing information. Information compression parameter determining means for obtaining an information compression parameter for each two-dimensional block relating to time and frequency, and the number of valid two-dimensional blocks for selecting the number information of valid two-dimensional blocks from a predetermined value of several bits In an encoding apparatus having information determining means, a filter processing is performed by adding or subtracting a desired value for each two-dimensional block with respect to normalized information of at least one of the two-dimensional blocks. Calculation means for performing the following processing, so that a signal in the time domain obtained by decoding a highly efficient encoded signal Filter processing can be realized with a smaller processing step and a simple configuration, and it is possible to filter an arbitrary portion of the signal in the time domain, and to convert a signal, which has been subjected to high-efficiency coding, into a certain recording medium. When it is desired to change the information in a time domain signal obtained by recording and decoding the recorded signal in a form in which a filter effect is applied and re-record the information, the processing can be realized with a smaller processing step and a simple configuration. Thus, it is possible to obtain an encoding device that can perform a filtering process on an arbitrary portion of the signal in the time domain and that can prevent quality deterioration due to operations such as inverse orthogonal transform and orthogonal transform.

According to the tenth aspect of the present invention, there is provided a band dividing means for dividing an input digital signal into a plurality of frequency band components,
Orthogonal transform means for obtaining signal components for encoding and / or analysis in a two-dimensional block, and numbering using several bits in advance based on the signal components in the two-dimensional block for each two-dimensional block relating to time and frequency Normalization data calculation means for performing normalization by selecting one of several positive values obtained as the normalization information and obtaining a number using the corresponding few bits as the normalization information, Quantization coefficient calculation means for obtaining a quantization coefficient representing a characteristic of a signal component in the two-dimensional block for each two-dimensional block relating to time and frequency; and bit allocation calculation means for determining a bit allocation amount based on the quantization coefficient. Compression encoding means for quantizing a signal component in a block with normalized data and a bit allocation amount for each two-dimensional block relating to time and frequency and compressing information;
Information compression parameter determining means for obtaining an information compression parameter for each two-dimensional block relating to time and frequency; and effective two-dimensional block number information determining means for selecting valid two-dimensional block number information from a predetermined value of several bits. Decoding means for decoding the signal components in the two-dimensional block related to time and frequency using the information compression parameter for each two-dimensional block related to time and frequency. Since there is an arithmetic means for adding or subtracting a desired value for each two-dimensional block with respect to the normalization information of at least one of the two-dimensional blocks and performing a filtering process, a signal which has been subjected to a high efficiency coding Filter processing on the time domain signal obtained by decoding It is possible to perform filtering of an arbitrary portion of the signal in the time domain, record a signal with high efficiency encoding on a recording medium, and decode the recorded signal. When it is desired to change the information of the signal in the time domain to a form in which a filter effect is applied and re-record the information, the processing can be realized with a smaller processing step and a simple configuration. It is possible to obtain a decoding device capable of performing the filtering process and realizing the prevention of the quality deterioration due to the operations such as the inverse orthogonal transform and the orthogonal transform.

According to the eleventh aspect of the present invention, the input digital signal is decomposed into a plurality of frequency band components to obtain signal components in a plurality of two-dimensional blocks relating to time and frequency. Then, based on the signal components in the two-dimensional block, normalization is performed by selecting, as normalization information, one of several positive values that have been numbered using several bits in advance. The number using several bits to be used as normalization information, a quantization coefficient representing the characteristic of the signal component in the two-dimensional block is obtained for each two-dimensional block relating to time and frequency, and the bit allocation amount is determined based on the quantization coefficient. Determine, quantize the signal components in the block by the normalized data and the bit allocation amount for each two-dimensional block related to time and frequency, and compress the information, and for each two-dimensional block related to time and frequency. In a digital signal recording method, at least one of a plurality of two-dimensional blocks is recorded on a recording medium together with an information compression parameter and information on the number of valid two-dimensional blocks selected from a predetermined number of bits. Digital signal filtering is performed by adding or subtracting a desired value for each two-dimensional block with respect to the normalized information of the two-dimensional block, so that a signal that has been subjected to high-efficiency encoding is decoded. Filter processing on the signal in the time domain
It can be realized with a smaller processing step and a simple configuration, enables filtering of an arbitrary portion of the signal in the time domain, records a highly efficient encoded signal on a recording medium, and When it is desired to change the information in the time domain signal obtained by decoding the recorded signal and re-record the information by applying a filter effect, the processing can be realized with a smaller processing step and a simple configuration. It is possible to obtain a digital signal recording method capable of performing an arbitrary filtering process on the signal of the above and realizing the prevention of quality deterioration due to operations such as inverse orthogonal transform and orthogonal transform.

According to the twelfth aspect of the present invention, in the digital signal recording method according to the eleventh aspect of the present invention, the normalized information subjected to the filtering process is re-recorded on the recording medium, so that the highly efficient encoded signal is recorded. The filtering process can be realized with a smaller processing step and a simple configuration for the time domain signal obtained by decoding, and the filtering process of an arbitrary portion of the time domain signal is possible, and the inverse orthogonal transform is performed. In addition, a digital signal recording method that can prevent the quality deterioration due to the operation such as the orthogonal transformation can be obtained.

According to the thirteenth aspect of the present invention, there is provided a band dividing means for dividing an input digital signal into a plurality of frequency band components,
Orthogonal transform means for obtaining signal components for encoding and / or analysis in a two-dimensional block, and numbering using several bits in advance based on the signal components in the two-dimensional block for each two-dimensional block relating to time and frequency Normalization data calculation means for performing normalization by selecting one of several positive values obtained as the normalization information and obtaining a number using the corresponding few bits as the normalization information, Quantization coefficient calculation means for obtaining a quantization coefficient representing a characteristic of a signal component in the two-dimensional block for each two-dimensional block relating to time and frequency; and bit allocation calculation means for determining a bit allocation amount based on the quantization coefficient. Compression encoding means for quantizing a signal component in a block with normalized data and a bit allocation amount for each two-dimensional block relating to time and frequency and compressing information;
Information compression parameter determining means for obtaining an information compression parameter for each two-dimensional block relating to time and frequency; and effective two-dimensional block number information determining means for selecting valid two-dimensional block number information from a predetermined value of several bits. In a digital signal recording apparatus comprising: a compression encoding unit, an information compression parameter determining unit, and an effective two-dimensional block number information determining unit, each output of which is recorded on a recording medium. Since there is an arithmetic means for adding or subtracting a desired value for each two-dimensional block with respect to the normalized information of one two-dimensional block and performing a filtering process, a signal which has been subjected to high efficiency coding is decoded. Filter processing for the time-domain signal can be realized with smaller processing steps and a simple configuration. In this case, it is possible to perform a filtering process of an arbitrary portion of the signal in the time domain, record a signal that has been subjected to high-efficiency coding on a certain recording medium, and decode the signal in the time domain obtained by decoding the recorded signal. , If you want to change the information to a filtered form and re-record it,
It can be realized with smaller processing steps and a simple configuration, and it is possible to filter any part of the signal in the time domain, and also to prevent quality deterioration due to operations such as inverse orthogonal transform and orthogonal transform. A digital signal recording device that can be realized can be obtained.

According to the fourteenth aspect of the present invention, in the digital signal recording apparatus according to the thirteenth aspect of the present invention, the normalized information filtered by the arithmetic means is re-recorded on the recording medium. Filter processing of the time-domain signal obtained by decoding the efficiency-coded signal can be realized with a smaller processing step and a simple configuration, and any part of the time-domain signal can be filtered. In addition, it is possible to obtain a digital signal recording device that can prevent the quality deterioration due to the operations such as the inverse orthogonal transform and the orthogonal transform.

According to the fifteenth aspect of the present invention, an input digital signal is decomposed into a plurality of frequency band components to obtain signal components in a plurality of two-dimensional blocks relating to time and frequency. Then, based on the signal components in the two-dimensional block, normalization is performed by selecting, as normalization information, one of several positive values that have been numbered using several bits in advance. The number using several bits to be used as normalization information, a quantization coefficient representing the characteristic of the signal component in the two-dimensional block is obtained for each two-dimensional block relating to time and frequency, and the bit allocation amount is determined based on the quantization coefficient. Determine, quantize the signal components in the block by the normalized data and the bit allocation amount for each two-dimensional block related to time and frequency, and compress the information, and for each two-dimensional block related to time and frequency. In information compression parameter, and the recorded recording medium number information of the two-dimensional blocks to effective with those selected from the predefined value by the number bits, at least one of the plurality of two-dimensional blocks
By adding or subtracting a desired value for each two-dimensional block to or from the two-dimensional block normalization information, the digital signal is filtered, and the normalized information after the filter processing is performed. Because it will be recorded,
Filter processing on a signal in the time domain obtained by decoding a signal subjected to high-efficiency encoding can be realized with a smaller processing step and a simple configuration, and filtering on an arbitrary portion of the signal in the time domain can be performed. And record the signal with high efficiency coding on a certain recording medium, and re-record the signal in the time domain obtained by decoding the recorded signal, changing the information to a form in which a filter effect has been applied. If it is desired, it can be realized with a smaller processing step and a simple configuration, and it is possible to perform a filtering process on an arbitrary portion of the signal in the time domain, and perform an inverse orthogonal transform,
It is possible to obtain a recording medium that can prevent the quality deterioration due to the operation such as the orthogonal transformation.

According to the sixteenth aspect of the present invention, an input digital signal is decomposed into a plurality of frequency band components to obtain signal components in a plurality of two-dimensional blocks relating to time and frequency. Then, based on the signal components in the two-dimensional block, normalization is performed by selecting, as normalization information, one of several positive values that have been numbered using several bits in advance. The number using several bits to be used as normalization information, a quantization coefficient representing the characteristic of the signal component in the two-dimensional block is obtained for each two-dimensional block relating to time and frequency, and the bit allocation amount is determined based on the quantization coefficient. Determine, quantize the signal components in the block by the normalized data and the bit allocation amount for each two-dimensional block related to time and frequency, and compress the information, and for each two-dimensional block related to time and frequency. In a digital signal transmission method for transmitting an information compression parameter and information on the number of valid two-dimensional blocks with a value selected from a predetermined number of bits, at least one of the plurality of two-dimensional blocks is transmitted. A digital signal is filtered by adding or subtracting a desired value for each two-dimensional block to or from the normalized information, and the digital signal after the filtering is transmitted. Filter processing of a time-domain signal obtained by decoding an encoded signal can be realized with a smaller processing step and a simple configuration, and an arbitrary part of the time-domain signal can be filtered. To record a signal with high efficiency encoding on a recording medium and decode the recorded signal. If it is desired to change and re-record the information in the time domain signal with the filter effect applied thereto, it can be realized with a smaller processing step and a simple configuration, and any part of the time domain signal can be realized. Can be obtained, and a digital signal transmission method capable of realizing prevention of quality deterioration due to operations such as inverse orthogonal transform and orthogonal transform can be obtained.

According to the seventeenth aspect of the present invention, there is provided a band dividing means for dividing an input digital signal into a plurality of frequency band components,
Orthogonal transform means for obtaining signal components for encoding and / or analysis in a two-dimensional block, and numbering using several bits in advance based on the signal components in the two-dimensional block for each two-dimensional block relating to time and frequency Normalization data calculation means for performing normalization by selecting one of several positive values obtained as the normalization information and obtaining a number using the corresponding few bits as the normalization information, Quantization coefficient calculation means for obtaining a quantization coefficient representing a characteristic of a signal component in the two-dimensional block for each two-dimensional block relating to time and frequency; and bit allocation calculation means for determining a bit allocation amount based on the quantization coefficient. Compression encoding means for quantizing a signal component in a block with normalized data and a bit allocation amount for each two-dimensional block relating to time and frequency and compressing information;
Information compression parameter determining means for obtaining an information compression parameter for each two-dimensional block relating to time and frequency; and effective two-dimensional block number information determining means for selecting valid two-dimensional block number information from a predetermined value of several bits. A digital signal transmitting apparatus for transmitting each output of the compression encoding means, the information compression parameter determining means, and the effective two-dimensional block number information determining means, wherein at least one of the two-dimensional blocks is Since there are arithmetic means for adding or subtracting a desired value for each two-dimensional block to or from the normalized information to perform filter processing, and transmission means for transmitting a digital signal after performing filter processing, Filter processing on the time domain signal obtained by decoding the highly efficient encoded signal has been reduced. It can be realized with simple processing steps and a simple configuration, enables filter processing of an arbitrary portion of a signal in the time domain, records a highly efficient encoded signal on a recording medium, and records the signal. When it is desired to change the information in the time domain signal obtained by decoding the decoded signal and re-record the information in a form in which a filter effect has been applied, this can be realized with a smaller processing step and a simpler configuration. It is possible to obtain a digital signal transmitting apparatus capable of performing a filtering process on an arbitrary portion of a signal and realizing prevention of quality deterioration due to operations such as inverse orthogonal transform and orthogonal transform.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram showing a specific example of a high-efficiency compression encoding encoder that can be used for bitrate compression encoding according to the present embodiment.

FIG. 2 is a diagram illustrating a structure of an orthogonal transform block at the time of bit compression.

FIG. 3 is a block circuit diagram showing an example of a bit allocation operation function.

FIG. 4 is a diagram illustrating spectra of each critical band and a band divided in consideration of block floating.

FIG. 5 is a diagram showing a masking spectrum.

FIG. 6 is a diagram in which a minimum audible curve and a masking spectrum are combined.

FIG. 7 is a diagram showing how data is encoded.

FIG. 8 is a diagram showing details of data of a first byte in FIG. 7;

FIG. 9 is a block circuit diagram showing a specific example of a high-efficiency compression encoding decoder which can be used for bitrate compression encoding in the above embodiment.

FIG. 10 is an explanatory diagram 1 of a low-pass filter.

FIG. 11 is an explanatory diagram 2 of a low-pass filter.

FIG. 12 is a block diagram illustrating a recording apparatus according to an embodiment of the present invention.

FIG. 13 is a block diagram illustrating a playback device according to an embodiment of the present invention.

FIG. 14 is a block diagram illustrating a transmission device according to an embodiment of the present invention.

FIG. 15 is a block diagram showing a receiving device according to an embodiment of the present invention.

[Explanation of symbols]

101, 102 band division filter, 103, 104,
105 orthogonal transform circuit (MDCT), 109, 110,
111 block determination circuit, 118 bit allocation calculation circuit, 106, 107, 108 adaptive bit allocation coding circuit, 119 normalization information adjustment circuit, 120, 121,
122 adder (subtractor), 302 energy calculator per band, 303 convolution filter, 304 subtractor, 30
5 function generator, 306 division circuit, 307 minimum audible curve generation circuit, 308 synthesis circuit, 309 subtraction circuit,
310 delay circuit, 311 allowable noise correction circuit, 90
1, 902 band synthesis filter (IQMF), 903,
904, 905 inverse orthogonal transform circuit (IMDCT), 90
6 adaptive bit allocation decoding circuit, 909 addition circuit, 9
10 input terminal, 911 normalization information adjustment circuit, ENC
Encoder, MOD modulation means, REC recording means,
P reproduction means, dem demodulation means, DEC decoder,
TX transmitting means, RX receiving means.

Claims (17)

[Claims] 1. An input digital signal is decomposed into a plurality of frequency band components to obtain signal components in a plurality of two-dimensional blocks relating to time and frequency.
For each dimension block, based on the signal components in the two-dimensional block,
Normalization is performed by selecting one of several positive values that have been numbered using several bits in advance as normalization information, and the number using the corresponding several bits is used as normalization information. A quantization coefficient representing a characteristic of a signal component in the two-dimensional block is obtained for each of the two-dimensional blocks relating to time and frequency, and a bit allocation amount is determined based on the quantization coefficient; For each time, the information component in the block is quantized by the normalized data and the bit allocation amount to compress the information, and the information compression parameter for the two-dimensional block relating to the time and frequency is obtained, and the number information of the valid two-dimensional block is obtained. Is selected from a value defined in advance by several bits, wherein at least one two-dimensional block of the plurality of two-dimensional blocks is selected. An encoding method characterized in that a filtering process of a digital signal is performed by adding or subtracting a desired value for each two-dimensional block with respect to the normalized information. 2. The encoding method according to claim 1, wherein a low-pass filter is realized by calculating normalization information of a two-dimensional block corresponding to a high-frequency component among the plurality of frequency band components. Encoding method characterized by having done. 3. The encoding method according to claim 1, wherein a high-pass filter is realized by calculating normalized information of a two-dimensional block corresponding to a low-frequency component among the plurality of frequency band components. Encoding method characterized by having done. 4. The encoding method according to claim 1, wherein normalization information of a two-dimensional block corresponding to a band other than the predetermined band among the plurality of frequency band components is calculated to pass the predetermined band. An encoding method characterized by realizing a bandpass filter having a band. 5. An input digital signal is decomposed into a plurality of frequency band components to obtain signal components in a plurality of two-dimensional blocks relating to time and frequency.
For each dimension block, based on the signal components in the two-dimensional block,
Normalization is performed by selecting one of several positive values that have been numbered using several bits in advance as normalization information, and the number using the corresponding several bits is used as normalization information. A quantization coefficient representing a characteristic of a signal component in the two-dimensional block is obtained for each of the two-dimensional blocks relating to time and frequency, and a bit allocation amount is determined based on the quantization coefficient; In each case, the signal component in the block is quantized by the normalized data and the bit allocation amount to compress the information, and the information compression parameter for each two-dimensional block relating to the time and frequency is obtained, and the number information of the valid two-dimensional block is obtained. Is selected from a value defined in advance by several bits, and the signal component for each two-dimensional block relating to the time and frequency of the information compression is
In the decoding method in which decoding is performed using the information compression parameter for each two-dimensional block relating to time and frequency, at least one of the plurality of two-dimensional blocks may be decoded.
A decoding method characterized by performing a filtering process on a digital signal by adding or subtracting a desired value for each two-dimensional block with respect to normalization information of a dimensional block. 6. The decoding method according to claim 5, wherein a low-pass filter is realized by calculating normalization information of a two-dimensional block corresponding to a high-frequency component among the plurality of frequency band components. A decoding method, characterized in that: 7. The decoding method according to claim 5, wherein a high-pass filter is realized by calculating normalization information of a two-dimensional block corresponding to a low-frequency component among the plurality of frequency band components. A decoding method, characterized in that: 8. The decoding method according to claim 5, wherein normalization information of a two-dimensional block corresponding to a band other than the predetermined band among the plurality of frequency band components is calculated to pass the predetermined band. A decoding method characterized by realizing a bandpass filter having a band. 9. A band dividing means for dividing an input digital signal into a plurality of frequency band components, encoding in a plurality of two-dimensional blocks relating to time and frequency by orthogonally transforming the signal,
And or orthogonal transformation means for obtaining a signal component for analysis,
Based on the signal components in the two-dimensional block for each of the two-dimensional blocks relating to time and frequency, one of several positive values that have been numbered using several bits in advance is selected as normalization information. A normalized data calculating means for performing normalization to obtain a number using the corresponding several bits as the normalized information, and representing the characteristics of the signal components in the two-dimensional block for each of the two-dimensional blocks relating to time and frequency. Quantization coefficient calculation means for obtaining a quantization coefficient, bit allocation calculation means for determining a bit allocation amount based on the quantization coefficient, and the above-described normalized data and bit allocation amount for each of the two-dimensional blocks relating to time and frequency. Compression encoding means for quantizing a signal component in the block to compress the information, and an information pressure for obtaining an information compression parameter for each two-dimensional block relating to the time and frequency. An encoding apparatus comprising: a parameter determining unit; and a valid two-dimensional block number information determining unit that selects valid number information of a two-dimensional block from a predetermined value with a few bits. One of two
What is claimed is: 1. An encoding apparatus comprising: arithmetic means for adding or subtracting a desired value for each two-dimensional block with respect to normalized information of a dimensional block to perform a filtering process. 10. A band dividing means for dividing an input digital signal into a plurality of frequency band components, and a signal component for encoding and / or analyzing a time and frequency in a plurality of two-dimensional blocks by orthogonally transforming the signal. And one of several positive values that are numbered using several bits in advance based on the signal components in the two-dimensional block for each of the two-dimensional blocks related to time and frequency. Is selected as normalization information to perform normalization, and a normalized data calculation means for obtaining a number using the corresponding several bits as normalization information;
Quantization coefficient calculation means for obtaining a quantization coefficient representing a characteristic of a signal component in a two-dimensional block for each dimension block; bit allocation calculation means for determining a bit allocation amount based on the quantization coefficient; Compression coding means for quantizing the signal components in the block by the normalized data and the bit allocation amount for each two-dimensional block for information compression, and information compression for obtaining the information compression parameter for each two-dimensional block regarding the time and frequency Parameter determining means, valid two-dimensional block number information determining means for selecting the number information of valid two-dimensional blocks from a predetermined number of bits, and two-dimensional information relating to the time and frequency of the information compression.
Decoding means for decoding a signal component in the two-dimensional block using the information compression parameter for each two-dimensional block relating to time and frequency, wherein at least one of the plurality of two-dimensional blocks
A decoding device, comprising: an arithmetic unit for adding or subtracting a desired value for each two-dimensional block with respect to normalized information of a dimensional block and performing a filtering process. 11. An input digital signal is decomposed into a plurality of frequency band components to obtain signal components in a plurality of two-dimensional blocks relating to time and frequency. Based on the signal components, normalization was performed by selecting one of several positive values, which were numbered using several bits in advance, as normalization information, and the above-mentioned several bits were used. Using the numbers as normalization information, a quantization coefficient representing the characteristic of the signal component in the two-dimensional block is obtained for each of the two-dimensional blocks related to the time and frequency, and a bit allocation amount is determined based on the quantization coefficient. For each two-dimensional block related to time and frequency, signal components in the block are quantized by the above-described normalized data and the bit allocation amount to compress information, and for each two-dimensional block related to time and frequency. A digital signal recording method for recording, on a recording medium, an information compression parameter and information on the number of two-dimensional blocks to be effective together with values selected from a predetermined number of bits, wherein at least one of the plurality of two-dimensional blocks is recorded. Two two
A digital signal recording method characterized by performing a digital signal filtering process by adding or subtracting a desired value for each two-dimensional block with respect to normalized information of a dimensional block. 12. The digital signal recording method according to claim 11, wherein the filtered normalized information is re-recorded on the recording medium. 13. A band dividing means for dividing an input digital signal into a plurality of frequency band components, and a signal component for encoding and / or analyzing a plurality of two-dimensional blocks relating to time and frequency by orthogonally transforming the signal. And one of several positive values that are numbered using several bits in advance based on the signal components in the two-dimensional block for each two-dimensional block related to time and frequency. Is selected as the normalization information to perform normalization, and a normalized data calculation means for obtaining a number using the corresponding several bits as the normalization information;
Quantization coefficient calculation means for obtaining a quantization coefficient representing a characteristic of a signal component in a two-dimensional block for each dimension block; bit allocation calculation means for determining a bit allocation amount based on the quantization coefficient; Compression encoding means for quantizing the signal components in the block by the normalized data and the bit allocation amount for each two-dimensional block, and compressing the information, and information compression for obtaining the information compression parameter for each two-dimensional block relating to the time and frequency A compression deciding means and an information compression parameter deciding means, comprising: a parameter deciding means; And digital signal recording in which each output of the effective two-dimensional block number information determining means is recorded on a recording medium. In location, the at least one of the plurality of two-dimensional blocks 2
A digital signal recording apparatus, comprising: arithmetic means for adding or subtracting a desired value for each two-dimensional block with respect to normalized information of a dimensional block and performing a filtering process. 14. The digital signal recording apparatus according to claim 13, wherein the normalized information filtered by the arithmetic means is re-recorded on the recording medium. 15. An input digital signal is decomposed into a plurality of frequency band components to obtain signal components in a plurality of two-dimensional blocks relating to time and frequency. Based on the signal components, normalization was performed by selecting one of several positive values, which were numbered using several bits in advance, as normalization information, and the above-mentioned several bits were used. Using the numbers as normalization information, a quantization coefficient representing the characteristic of the signal component in the two-dimensional block is obtained for each of the two-dimensional blocks related to the time and frequency, and a bit allocation amount is determined based on the quantization coefficient. For each two-dimensional block related to time and frequency, the signal component in the block is quantized by the normalized data and the bit allocation amount to compress the information, and for each two-dimensional block related to the time and frequency. In a recording medium in which an information compression parameter and information on the number of valid two-dimensional blocks selected from a predetermined number of bits are recorded, at least one of the plurality of two-dimensional blocks is recorded.
Digital signal filtering is performed by adding or subtracting a desired value for each two-dimensional block from the normalized information of the two-dimensional block, and the normalized information after the filtering is recorded. A recording medium characterized by comprising: 16. An input digital signal is decomposed into a plurality of frequency band components to obtain signal components in a plurality of two-dimensional blocks relating to time and frequency. Based on the signal components, normalization was performed by selecting one of several positive values, which were numbered using several bits in advance, as normalization information, and the above-mentioned several bits were used. Using the numbers as normalization information, a quantization coefficient representing the characteristic of the signal component in the two-dimensional block is obtained for each of the two-dimensional blocks related to the time and frequency, and a bit allocation amount is determined based on the quantization coefficient. For each two-dimensional block related to time and frequency, the signal component in the block is quantized by the normalized data and the bit allocation amount to compress the information, and for each two-dimensional block related to the time and frequency. A digital signal transmission method for transmitting an information compression parameter and information on the number of valid two-dimensional blocks together with a value selected from a predetermined number of bits, wherein at least one of the plurality of two-dimensional blocks is transmitted.
Filtering a digital signal by adding or subtracting a desired value for each two-dimensional block with respect to the normalized information of a dimensional block, and transmitting the digital signal after the filtering. A digital signal transmission method characterized by the above-mentioned. 17. A band dividing means for dividing an input digital signal into a plurality of frequency band components, and a signal component for encoding and / or analyzing a plurality of two-dimensional blocks relating to time and frequency by orthogonally transforming the signal. And one of several positive values that are numbered using several bits in advance based on the signal components in the two-dimensional block for each of the two-dimensional blocks related to time and frequency. Is selected as normalization information to perform normalization, and a normalized data calculation means for obtaining a number using the corresponding several bits as normalization information;
Quantization coefficient calculation means for obtaining a quantization coefficient representing a characteristic of a signal component in a two-dimensional block for each dimension block; bit allocation calculation means for determining a bit allocation amount based on the quantization coefficient; Compression coding means for quantizing the signal components in the block by the normalized data and the bit allocation amount for each two-dimensional block, and compressing information, and information compression for obtaining the information compression parameter for each two-dimensional block relating to the time and frequency The compression encoding means and the information compression parameter deciding means, comprising: parameter deciding means; And a digital signal transmitting device for transmitting each output of the effective two-dimensional block number information determining means. At least one of the two-dimensional blocks of numbers
Calculating means for adding or subtracting a desired value for each two-dimensional block with respect to the normalized information of the dimensional block to perform a filtering process; and transmitting means for transmitting a digital signal after the filtering process is performed. A digital signal transmitting device comprising: