JP4534112B2 - Encoding apparatus and method, decoding apparatus and method, recording medium, and program - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an encoding apparatus and method, a decoding apparatus and method, a recording medium, and a program, and encodes input digital data by so-called high-efficiency encoding, and transmits, records, reproduces, decodes, and reproduces a reproduced signal The present invention relates to an encoding device and method, a decoding device and method, a recording medium, and a program that are suitable for use in obtaining the above.
[0002]
[Prior art]
There are various techniques for high-efficiency encoding of signals such as audio or voice. For example, non-blocking frequency band that divides and encodes audio signals on the time axis into multiple frequency bands without blocking them The division method, band division coding (subband coding: SBC (Subband Coding)), and the time axis signal is converted to a signal on the frequency axis (spectrum conversion) and divided into multiple frequency bands. In addition, a blocked frequency band division method for encoding for each band, so-called transform coding, and the like can be given.
[0003]
In addition, a high-efficiency coding method combining the above-described band division coding and transform coding is also considered. In this case, for example, after performing band division by band division coding, each band Is spectrally converted to a signal on the frequency axis, and each spectrum-converted band is encoded. Examples of the band division filter described above include, for example, a QMF filter (Quadrature Mirror Filter). For example, 1976 RECrochiere Digital coding of speech in subbands, Bell Syst.Tech. J. Vol.55, It is stated in No.8 1976.
[0004]
Also, ICASSP 83, BOSTON Polyphase Quadrature filters-A new subband coding technique, Joseph H. Rothweiler, describes an equal-bandwidth filter division technique. Here, as the above-described spectral transformation, for example, the input audio signal is blocked in a predetermined unit time (frame), and discrete Fourier transform (DFT), discrete cosine transform (Discrete Cosine Transform) is performed for each block. (DCT), Modified DCT transform (Modified Discrete Cosine Transform) (MDCT), etc., there is a spectrum conversion that converts the time axis to the frequency axis. MDCT is described, for example, in ICASSP 1987 Subband / Transform Coding Using Filter Bank Designs Based on Time Domain Aliasing Cancellation, JPPrincen ABBradley Univ. Of Surrey Royal Melbourne Inst. Of Tech.
[0005]
By quantizing the signal divided for each band by the filter or spectrum conversion in this way, it is possible to control the band in which the quantization noise is generated. More efficient encoding can be performed. If the normalization is performed for each band, for example, with the maximum absolute value of the signal component in each band before the quantization is performed here, more efficient encoding can be performed.
[0006]
As a frequency division width for quantizing each frequency component obtained by frequency band division, for example, band division considering human auditory characteristics is performed. In other words, the audio signal may be divided into a plurality of bands (for example, 32 band) with a bandwidth that is generally called a critical band (critical band) and that the bandwidth becomes wider as the high frequency band increases. Further, when encoding the data for each band at this time, encoding is performed by predetermined bit allocation for each band or adaptive bit allocation (bit allocation) for each band. .
[0007]
For example, when the coefficient data obtained by the MDCT processing is encoded by the bit allocation, adaptive allocation bits are assigned to the MDCT coefficient data for each band obtained by the MDCT processing for each block. Encoding is performed with numbers. The following two methods are known as bit allocation methods.
[0008]
The first method is disclosed in Adaptive Transform Coding of Speech Signals, R. Zelinski and P. Noll, IEEE Transactions of Accoustics, Speech, and Signal Processing, vol. ASSP-25, No. 4, August 1977. Here, bit allocation is performed based on the signal size of each band. In this method, the quantization noise spectrum is flattened and the noise energy is minimized. However, since the masking effect is not used audibly, the actual noise feeling is not optimal.
[0009]
The second method is disclosed in ICASSP 1980 The critical band coder-digital encoding of the perceptual requirements of the auditory system, MAKransner MIT. This describes a technique for obtaining a signal-to-noise ratio necessary for each band by using auditory masking and performing fixed bit allocation. However, with this method, even when the characteristic is measured with a sine wave input, the characteristic value is not so good because the bit allocation is fixed.
[0010]
In order to solve these problems, all the bits that can be used for bit allocation are divided into fixed bit allocation patterns determined in advance for each small block and bit allocation depending on the signal size of each block. There has been proposed a high-efficiency encoding device that is used in division, and that makes the division ratio depend on a signal related to an input signal, and increases the division ratio into the fixed bit allocation pattern as the spectrum of the signal is smoother.
[0011]
According to this device, when energy is concentrated in a specific spectrum such as a sine wave input, the overall signal-to-noise characteristics can be significantly improved by allocating many bits to the block containing the spectrum. Can do. In general, human hearing is very sensitive to signals with steep spectral components, so using this method to improve signal-to-noise characteristics simply improves the numerical value of the measurement. Rather, it is effective in improving sound quality in terms of hearing.
[0012]
A number of other bit allocation methods have been proposed, and if the auditory model is refined and the coding device is capable, coding can be performed more efficiently from an auditory perspective. become.
[0013]
Further, the present inventors previously proposed a method for separating a tone component particularly important for hearing from a spectrum signal and encoding it separately from other spectrum components as Japanese Patent Application No. 5-152865. As a result, it is possible to efficiently encode an audio signal or the like with a high compression rate without causing any audible degradation.
[0014]
As a method for converting a waveform signal into a spectrum, when the above-described DFT or DCT is used, M independent real number data can be obtained by performing conversion in a time block composed of M samples. In order to reduce the connection distortion between time blocks, normally M1 samples overlap each other on both adjacent blocks, so on average, M samples for (M-M1) samples in DFT and DCT The real number data is quantized and encoded.
[0015]
On the other hand, when the above-mentioned MDCT is used as a method for converting into a spectrum, M independent real data is obtained from 2M samples overlapped by N times each adjacent time, so the average In MDCT, M real data is quantized and encoded for M samples. In the decoding apparatus, it is possible to reconstruct the waveform signal by adding the waveform elements obtained by performing inverse transform in each block while interfering with each other from the code obtained by using MDCT in this way. it can.
[0016]
In general, by increasing the time block for conversion, the frequency resolution of the spectrum is increased, and energy is concentrated on a specific spectral component. Therefore, DFT is performed by overlapping with both adjacent blocks by a long block length and using MDCT in which the number of obtained spectrum signals does not increase with respect to the number of original time samples. Thus, it is possible to perform encoding more efficiently than when DCT is used. Further, by providing a sufficiently long overlap between adjacent blocks, it is possible to reduce the inter-block distortion of the waveform signal.
[0017]
In constructing an actual code string, first, quantization accuracy information and normalized coefficient information are encoded with a predetermined number of bits for each band in which normalization and quantization are performed, and then normalized and quantized. What is necessary is just to encode the obtained spectrum signal.
[0018]
In encoding a spectrum signal, a method using a variable length code such as a Huffman code is known. The Huffman code is described in, for example, David A. Huffman, “A Method for the Construction of Minimum-Redundancy Codes”, Proceedings of the IRE, pp 1098-1101, Sep., 1952.
[0019]
Furthermore, a method is known that uses a multidimensional variable-length code that represents a plurality of spectral signals together with a single code. In general, in an encoding method using a multidimensional variable length code, the higher the code order, the more efficient the encoding in terms of compression efficiency. However, since the scale of the code string table increases dramatically as the order increases, a practical problem arises. Actually, the optimum order is selected according to the purpose while considering the compression efficiency and the scale of the code string table.
[0020]
In general, in an acoustic waveform signal, energy is often concentrated on a fundamental frequency component and a frequency component that is an integral multiple of the fundamental frequency, that is, a so-called harmonic component, and the level of the spectrum signal around that frequency is very small compared to a so-called harmonic component. Therefore, the probability of being quantized to 0 increases. In order to efficiently encode such a signal, it is only necessary to encode a spectrum signal quantized to 0 having a high probability of occurrence with as little information as possible. When a one-dimensional variable length code is used, even if each spectrum signal is encoded with 1 bit of the shortest code length, N bits of information are required for N spectra. When a multi-dimensional variable length code of order N is used, N spectra can be encoded with 1 bit of the shortest code length, so that it is efficient for signals having the above frequency components. Can be encoded.
[0021]
However, in a coding method using a multi-dimensional variable length code, increasing the code order has a considerable advantage in terms of compression efficiency. However, considering practical application, the code order can be increased without limit. It is impossible.
[0022]
Usually, the code string table is prepared for each quantization accuracy information set for each band. When the quantization accuracy is low, the number of spectral signal values that can be expressed is small, so even if the order is increased, the scale of the code string table does not increase so much. Therefore, even if the order is increased by one, the size of the code string table is remarkably increased.
[0023]
The above will be further described using a specific example. Assume that the input signal is subjected to MDCT conversion to obtain a spectrum as shown in FIG. FIG. 1 shows the absolute value of the MDCT spectrum with the level converted to dB. The input signal is converted into 64 spectral signals for each predetermined time block, and these are combined into 8 encoding units [1] to [8], and normalization and quantization are performed.
[0024]
By changing the quantization accuracy for each encoding unit according to the distribution method of the frequency components, it is possible to perform audioly efficient encoding while minimizing deterioration of sound quality. The required quantization accuracy information in each encoding unit can be obtained by calculating the minimum audible level and the masking level in the band corresponding to each encoding unit based on the auditory model, for example. The normalized and quantized spectrum signal is converted into a variable-length code and encoded with quantization accuracy information and normalization information in each encoding unit.
[0025]
FIG. 2 is a diagram for explaining a method of expressing quantization accuracy information. When the quantization accuracy information code is expressed by 3 bits, a maximum of 8 types of quantization accuracy information can be set. In this example, the quantization is performed in any one of eight steps of 1, 3, 5, 7, 15, 31, 63, and 127. Here, the quantization in one step means that all the spectrum signals in the encoding unit are quantized to a value of zero.
[0026]
FIG. 3 is a diagram for explaining a variable length coding method that has been conventionally performed. The spectrum signal is quantized based on quantization accuracy information determined for each encoding unit, and a quantized spectrum is obtained. When a quantized spectrum is encoded, it is converted into a corresponding code string by referring to a code string table as shown in FIG. As is clear from FIG. 4, a code string table is prepared for each quantization accuracy information.
[0027]
In FIG. 3, in the encoding unit [1], the code “011” is selected as the quantization accuracy information. Therefore, as shown in FIG. 4, the quantization is performed with the number of steps of seven stages, and the value of the quantized spectrum signal (quantized spectrum) is 3, -1, 2, 2 When these are converted into code strings using the code string table whose quantization accuracy information code is “011” in FIG. 4, they become 1110, 101, 1100, and 1100, respectively, and the code lengths become 4, 3, 4, and 4, respectively.
[0028]
In the encoding unit [2], the code “010” is selected as the quantization accuracy information. In this case, as shown in FIG. 4, quantization is performed with the number of steps of five stages. In this example, the quantized spectrum is -2, 1, 0, 1 in order from the lowest frequency. When these are converted into code strings using the code string table whose quantization accuracy information code is “010” in FIG. 4, they become 111, 100, 0, and 100, respectively, and the code lengths become 3, 3, 1, and 3, respectively.
[0029]
Similarly, in the encoding unit [3], the code “001” is selected as the quantization accuracy information, the quantization is performed in three steps, and the quantization spectrum is 0, −1, 0, 0, The code string is 0, 11, 0, 0, and the code length is 1, 2, 1, 1.
[0030]
FIG. 5 is a diagram for explaining a two-dimensional variable length coding method. FIG. 5 shows an encoding unit similar to that in FIG.
[0031]
If a two-dimensional code sequence table as shown in FIG. 6 is used as the code sequence table when the quantization accuracy information code is “001”, the quantization spectrum of the encoding unit [3] in FIG. A group is converted into one code string. Accordingly, the quantized spectra 0, -1, 0, 0 of the four spectrum signals are grouped into two groups (0, -1) and (0, 0), and two codes 101, 0 are included. Converted to a column.
[0032]
When the spectrum signal of the encoding unit [3] is encoded with a one-dimensional variable length code as shown in FIG. 3, the required amount of information is 1 + 2 + 1 + 1 = 5 bits. On the other hand, as shown in FIG. 5, when encoded with a two-dimensional variable length code, the amount of information becomes 3 + 1 = 4 bits. That is, it can be seen that if the order is increased, encoding can be performed with a smaller amount of information.
[0033]
[Problems to be solved by the invention]
As described above, the quantized spectrums of a plurality of (N) spectrum signals are combined into one group to form N-dimensional data, which is encoded into a variable-length code according to the code sequence table. The code length can be shortened compared to the case of using a one-dimensional variable length code. However, when the order (value of N) increases, the scale of the code string table increases remarkably, and there is a problem that it is difficult to put it to practical use.
[0034]
For example, when a two-dimensional variable length code is used, the code string table when the quantization accuracy information code is “001”, “010”, “110” is one-dimensional variable as shown in FIGS. Compared to the code string table (FIG. 4) in the case of using a long code, the scale of the code string table is increased.
[0035]
The present invention has been made in view of such a situation, and can perform encoding with a short code length without increasing the scale of the code string table as in the case of using multidimensional variable length encoding. It is what you want to do.
[0036]
[Means for Solving the Problems]
The encoding device of the present invention adjusts the positive / negative of numerical values to unify the positive / negative of M numerical values, the first encoding means to encode the numerical values whose positive / negative are unified by the uniforming means, Calculate the number of numerical values other than the specific value among the M numerical values, and whether the numerical value other than the specific value is positive or negative By unified means Generate the number of information other than the calculated specific value to determine whether the adjustment has been made. Positive / negative information And positive and negative information A second encoding means for encoding, and a code string generating means for generating a code string including an output of the first encoding means and an output of the second encoding means are provided.
[0037]
The code string generation means can generate the code string so as to alternately include the output of the first encoding means and the output of the second encoding means.
[0039]
First The encoding means can encode the numerical value into a variable-length code string.
[0040]
The variable length code string may be a Huffman code.
[0041]
The numerical sequence can be a quantized acoustic waveform signal.
[0042]
The encoding method of the present invention adjusts the sign of a numerical value to unify the positive and negative values of M numerical values, and the first encoding step to encode a numerical value whose sign is unified in the processing of the unifying step When, Calculate the number of numerical values other than the specific value among the M numerical values. In the unified step process Generate the number of information other than the calculated specific value to determine whether the adjustment has been made. Positive / negative information And positive and negative information A second encoding step for encoding, and a code string generation step for generating a code string including an output in the process of the first encoding step and an output in the process of the second encoding step. Features.
[0043]
The first recording medium program of the present invention adjusts the sign of a numerical value to unify the positive and negative values of the M numerical values, and first encodes a numerical value whose sign is unified by the processing of the unified step. Encoding steps of Calculate the number of numerical values other than the specific value among the M numerical values, and whether the numerical value other than the specific value is positive or negative In the unified step process Generate the number of information other than the calculated specific value to determine whether the adjustment has been made. Positive / negative information And positive and negative information A second encoding step for encoding, and a code string generation step for generating a code string including an output in the process of the first encoding step and an output in the process of the second encoding step. Features.
[0044]
A first program of the present invention adjusts the sign of a numerical value to unify the positive and negative values of M numerical values, and a first encoding for encoding a numerical value whose sign is unified in the processing of the unified step Steps, Calculate the number of numerical values other than the specific value among the M numerical values, and whether the numerical value other than the specific value is positive or negative In the unified step process Generate the number of information other than the calculated specific value to determine whether the adjustment has been made. Positive / negative information And positive and negative information A process including a second encoding step for encoding, and a code string generation step for generating a code string including an output in the process of the first encoding step and an output in the process of the second encoding step. The computer is executed.
[0045]
In the encoding apparatus and method, the first recording medium program, and the first program of the present invention, the positive / negative of the numerical values are adjusted to unify the positive and negative values of the M numerical values. Encoded, The number of numerical values other than the specific value among the M numerical values is calculated, and information on whether the sign of the numerical value other than the specific value has been adjusted is generated by the number of numerical values other than the calculated specific value. Positive / negative information And positive and negative information Encoding is performed to generate a code string.
[0046]
The decoding apparatus according to the present invention includes a first code string that is encoded as one group by unifying the sign of the numerical values constituting the M number strings, and a numerical value that is adjusted when the sign is unified. Input means for receiving a code string including a second code string obtained by encoding information for specifying; decoding means for decoding the first code string; decoding the second code string; Calculate the number of numerical values other than the specific value among the M numerical values, and check whether the sign of the numerical value other than the specific value has been adjusted information , Only the number of numerical values other than the calculated specific value read Reading A sampling means, and a number sequence of M positive and negative values adjusted by the decoding means; Reading And a restoring unit that restores the positive / negative of the M number strings based on the information for identifying the numerical value adjusted for the positive and negative values read by the sampling unit.
[0047]
The input means can receive a code string including the first code string and the second code string alternately.
[0049]
Reading The sampling means can not read the second code string when the specific value is decoded by the decoding means.
[0050]
The specific value can be the value 0.
[0051]
According to the decoding method of the present invention, a first code string that is encoded as one group by unifying the positive and negative values of the M numerical value strings, and a numerical value that is adjusted when positive and negative are adjusted. An input step of receiving a code string including a second code string obtained by encoding information for specifying; a decoding step of decoding the first code string; and decoding the second code string; Calculate the number of numerical values other than the specific value among the M numerical values, and check whether the sign of the numerical value other than the specific value has been adjusted information , Only the number of numerical values other than the calculated specific value read Reading A numerical sequence in which M positive and negative values adjusted in the processing of the sampling step and the decoding step are adjusted; Reading And a restoration step for restoring the positive / negative of the M number sequence based on the information for identifying the numerical value adjusted in the positive / negative direction read in the processing of the sampling step.
[0052]
The program of the second recording medium of the present invention is such that the sign of the first code string encoded as one group by unifying the sign of the numerical values constituting the M number strings is positive and negative when the signs are unified. An input step for receiving a code string including a second code string obtained by encoding information for specifying the adjusted numerical value; a decoding step for decoding the first code string; and a decoding of the second code string , Calculate the number of numerical values other than the specific value among the M numerical values, and check whether the sign of the numerical value other than the specific value has been adjusted information , Only the number of numerical values other than the calculated specific value read Reading A numerical sequence in which M positive and negative values adjusted in the processing of the sampling step and the decoding step are adjusted; Reading And a restoration step for restoring the positive / negative of the M number sequence based on the information for identifying the numerical value adjusted in the positive / negative direction read in the processing of the sampling step.
[0053]
In the second program of the present invention, the positive / negative is adjusted when unifying positive and negative with the first code string encoded as one group by unifying the positive and negative values of the numerical values constituting the M numerical value strings. An input step for receiving a code string including a second code string obtained by encoding information for specifying a numerical value; a decoding step for decoding the first code string; and a decoding of the second code string; Calculate the number of numerical values other than the specific value among the M numerical values, and check whether the sign of the numerical value other than the specific value has been adjusted information , Only the number of numerical values other than the calculated specific value read Reading A numerical sequence in which M positive and negative values adjusted in the processing of the sampling step and the decoding step are adjusted; Reading And a restoration step for restoring the positive / negative of the M number sequence based on the information for identifying the numerical value adjusted in the positive / negative direction read in the processing of the sampling step.
[0054]
In the decoding apparatus and method, the program of the second recording medium, and the second program of the present invention, the first code encoded as one group by unifying the sign of the numerical values constituting the M numerical value sequences A code string including a code string and a second code string obtained by encoding information for specifying a numerical value whose sign is adjusted when unifying the sign is received, the first code string is decoded, 2 code strings are decoded, Whether the number of numerical values other than the specific value among the M numerical values is calculated, and whether the sign of the numerical value other than the specific value is adjusted Information , Only the number of numerical values other than the calculated specific value The positive and negative values of the M number sequences are restored based on the read and decoded number sequence of M numbers adjusted for positive and negative and the information for specifying the read numbers for adjusted positive and negative values.
[0055]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 9 shows a configuration example of an encoding apparatus to which the present invention is applied.
[0056]
The signal waveform 101 input to the encoding device is converted into a signal frequency component 102 by the conversion circuit 1, and then each component is encoded by the signal component encoding circuit 2, and a code string is generated by the code string generation circuit 3. It is made to be done. This code string is transmitted to a predetermined transmission path or recorded on the information recording medium 4.
[0057]
FIG. 10 shows a configuration example of the conversion circuit 1.
[0058]
The signal components 211 and 212 divided into two bands by the band dividing filter 11 are converted into the spectrum signal components 221 and 222 by the forward spectrum conversion circuits 12 and 13 such as MDCT in the respective bands. . The bandwidth of the signals 211 and 212 is ½ of the bandwidth of the signal 201 (decimated to ½ of the signal 201).
[0059]
10 corresponds to 101 in FIG. 9, and 221 and 222 in FIG. 10 correspond to 102 in FIG.
[0060]
Many other conversion circuits 1 can be considered besides this embodiment. For example, the input signal may be directly converted into a spectrum signal by MDCT, or may be converted by DFT or DCT instead of MDCT.
[0061]
Although it is possible to process the signal by simply dividing the signal into band components by the band division filter and not converting it to a spectrum, the method of the present invention works particularly effectively when energy is concentrated at a specific frequency. It is convenient to take a method of converting the frequency components into frequency components by spectral conversion in which a large number of frequency components are obtained with a relatively small amount of calculation.
[0062]
FIG. 11 shows a configuration example of the signal component encoding circuit 2.
[0063]
Each signal component 301 is normalized for each predetermined band by the normalization circuit 21, and then input to the quantization circuit 22 as a signal 302, and the quantization accuracy signal 303 calculated by the quantization accuracy determination circuit 23. The signal is quantized based on the signal and output as a signal 304. 11 in FIG. 11 corresponds to 102 in FIG. 9, and 304 in FIG. 11 corresponds to 103 in FIG. 9. Here, in addition to the quantized signal component, 304 (103) Normalization coefficient information and quantization accuracy information are also included.
[0064]
FIG. 12 shows a configuration example of the code string generation circuit 3.
[0065]
The control unit 31 converts the quantized spectrum 401 of the spectrum signal grouped into one group of M, for example, by converting a negative quantized spectrum into a positive value (takes an absolute value), and After unifying positive and negative, it is encoded by controlling the encoding unit 32.
[0066]
Further, the control unit 31 controls the encoding unit 33 so that the specific value is the number of bits based on the number of quantized spectra other than the specific value (value 0 in this example) among the M quantized spectra. And the data corresponding to the position in the group of the negative quantization spectrum is encoded, and information for specifying the negative quantization spectrum (hereinafter referred to as positive / negative code information sign) is generated.
[0067]
The code sequence (code sequence of the quantized spectrum) 402 generated by the encoding unit 32 and the code sequence (positive / negative code information sign) 403 generated by the encoding unit 33 are a predetermined transmission path or information recording medium 4 Is output.
[0068]
Note that 401 in FIG. 12 corresponds to 103 in FIG. 9, and 402 and 403 in FIG. 12 correspond to 104 in FIG.
[0069]
Next, the operation of the encoding device (FIG. 9) will be described. The acoustic waveform signal 101 (201) is input to the band dividing filter 11 (FIG. 10) of the conversion circuit 1, and is divided into a signal component 211 having a lower frequency and a signal component 212 having a higher frequency. The lower frequency signal component 211 is input to the forward spectrum conversion circuit 12 and converted to the spectrum signal component 221. Similarly, the higher frequency signal component 212 is input to the forward spectrum conversion circuit 13, converted to the spectrum signal component 222, and output.
[0070]
That is, with reference to FIG. 1, the forward spectrum conversion circuit 12 unitizes lower frequency spectrum signals to generate encoding units [1] to [6]. Further, the forward spectrum conversion circuit 13 unitizes higher frequency spectrum signal components to generate encoding units [7] and [8].
[0071]
The spectrum signal components 221 and 222 (102) output from the forward spectrum conversion circuits 12 and 13 are input to the normalization circuit 21 (FIG. 11) and the quantization accuracy determination circuit 23 of the signal component encoding circuit 2. The normalization circuit 21 performs normalization by dividing the value of each signal by the maximum value among the plurality of spectral signal components in the encoding unit. Then, the obtained normalization coefficient 302 is supplied to the quantization circuit 22.
[0072]
The quantization accuracy determination circuit 23 determines the quantization accuracy of the input spectrum signal component for each encoding unit by calculating the minimum audible level and the masking level in the band corresponding to each encoding unit. The quantization circuit 22 quantizes the normalization coefficient 302 supplied from the normalization circuit 21 with the quantization accuracy 303 supplied from the quantization accuracy determination circuit 23, and codes the obtained quantized spectrum 304 (103). This is supplied to the column generation circuit 3.
[0073]
The code string generation circuit 3 converts the quantized spectrum 304 into a code string, and details of the process will be described with reference to the flowchart of FIG.
[0074]
In step S1, the control unit 31 of the code string generation circuit 3 includes the value of the counter i that counts the number of spectrum signals collected in one group, the value of the register N, and the value of the register sign. Initially set to the value 0.
[0075]
Next, in step S2, the control unit 31 examines the quantized spectrum of the spectrum signal corresponding to the value of the counter i (hereinafter referred to as QSP (i) as appropriate), and it is a specific value (in this example, It is determined whether or not the value is 0). If it is determined that the value is not 0, the process proceeds to step S3.
[0076]
In step S3, the control unit 31 increases the value of the register N by 1 and shifts the value of the register sign to the left by 1 bit (doubles).
[0077]
Next, in step S4, the control unit 31 determines whether or not the quantized spectrum of QSP (i) is a negative value, and if it is determined to be a negative value, the process proceeds to step S5.
[0078]
In step S5, the control unit 31 multiplies the quantized spectrum of QSP (i) by the value -1, and sets the resulting value as the quantized spectrum of QSP (i). That is, when the quantized spectrum of QSP (i) is a negative value, it is converted to a positive value. At this time, the control unit 31 increases the value of the register sign by 1.
[0079]
If it is determined in step S4 that the quantized spectrum of QSP (i) is a positive value, the process of step S5 is skipped, and the process proceeds to step S6. Also, in step S2, the quantized spectrum of QSP (i) When it is determined that the value is 0, the processing from step S3 to step S5 is skipped, and the process proceeds to step S6.
[0080]
In step S6, the control unit 31 increments the value of the counter i by 1. In step S7, the control unit 31 determines whether or not the value of the counter i is less than the number M of spectrum signals collected in one group. If it is determined that it is less than M, the process returns to step S2, and the subsequent processing is executed.
[0081]
When it is determined in step S7 that the value of the counter i is not less than the number M of spectrum signals (when it is more than that), the process proceeds to step S8, and the control unit 31 controls the encoding unit 32, The quantized spectrum of QSP (0) to QSP (M-1), that is, the quantized spectrum collected in one group is encoded with an M-dimensional variable length code.
[0082]
For example, when a two-dimensional variable length code is formed (when M = 2), the encoding unit 32 refers to a code string table as shown in FIG. The quantized spectrum is converted into a code string corresponding to the quantized spectrum.
[0083]
FIG. 14 shows a code string in the case where the quantization accuracy information code is “001”, a code string table in the case of “010”, and a code string table in the case of “011”. 4 code strings, 9 word code strings, and 16 word code strings are prepared.
[0084]
In the case of this example, the negative value quantized spectrum is converted to a positive value (step S5), and therefore the negative value quantized spectrum is not encoded. Therefore, the code string table of FIG. 14 does not include a code string corresponding to a negative quantization spectrum. In this way, for example, by unifying the quantized spectrum to a positive value, it is not necessary to prepare a code string corresponding to the negative quantized spectrum, and therefore the scale of the code string table can be reduced accordingly. .
[0085]
On the other hand, in the conventional variable length code, since the code string corresponding to the quantized spectrum of the positive value and the negative value has to be prepared, the scale of the code string becomes large. For example, in the code string table when the quantization accuracy information code in the two-dimensional variable length code is “001”, the code string table of 9 words shown in FIG. 6 is prepared, and the code string table in the case of “010” The code string of 25 words shown in FIG. 7 is prepared, and the code string table of 49 words shown in FIG. 8 needs to be prepared in the code string table in the case of “011”.
[0086]
Although illustration thereof is omitted, in the case of four dimensions, when the quantization accuracy information code is “010” and “011”, the size of the code string table of the present invention is 81 words and 256 words. In this case, it becomes 625 words and 2401 words.
[0087]
Returning to FIG. 13, in step S9, the control unit 31 controls the encoding unit 33 to encode the value of the register sign with the same number of bits as the value of the register N. Is generated.
[0088]
Thereafter, the process ends, and the processes in steps S1 to S9 are similarly performed on the quantized spectra of the spectrum signals collected in the next group.
[0089]
Next, as an example of the coding unit (16 or [8] coding unit in the example of FIG. 1) shown in FIG. The operation will be described again. In the case of this example, it is assumed that 2 (= M) spectral signals of the encoding unit are grouped into one group.
[0090]
In the case of encoding the quantized spectra (1, -2) of two spectrum signals from the lowest frequency, when the counter i = 0, the register N = 0, and the register sign = 0 (step S1), Since the quantized spectrum (value 1) of QSP (0) is not the value 0 (step S2), the value 0 of the register N is increased by 1 to become the value 1, and the value 0 of the register sign is doubled. 0 (step S3).
[0091]
Further, since the quantized spectrum (value 1) of QSP (0) is a positive value (step S4), the value 0 of the counter i is increased by 1 to become a value 1 (step S6).
[0092]
Since the quantized spectrum (value-2) of QSP (1) is not 0, the value 1 of the register N is further increased by 1 to become the value 2, and the value 0 of the register sign is doubled to become the value 0. Become.
[0093]
Further, since the quantized spectrum (value-2) of QSP (1) is a negative value, 2 (= −2 × −1) is the quantized spectrum of QSP (1) to be encoded ( Step S5). At this time, the value 0 of the register sign is incremented by 1 to become the value 1.
[0094]
In other words, in this case, (1,2) is encoded as 5 bits “11110” based on the code string table of FIG. 14 (step S8), and subsequently, the value 1 of the register sign is It is encoded into the number of bits of N value 2, that is, a 2-bit code string “01”, and positive / negative code information sign “01” is generated (step S9).
[0095]
The positive / negative sign information sign represents that the value encoded in step S8 corresponding to the “1” is a negative value. In this case, (1, −2) is encoded as (1,2), but the sign information “01” at this time corresponds to “1”, (1,2). "2" in () indicates that it is originally a negative value (-2). In a decoding apparatus to be described later, the sign of the signal component is determined based on the sign information sign.
[0096]
The encoding unit shown in FIG. 15 is 5 bits “11110” ((1,2) code string) and 2 bits “01” (code string of the register sign of value 1), 1 in the present invention. Bit “0” (code sequence of (0,0)), 3-bit “101” (code sequence of (1,0)) and 1 bit “0” (code sequence of register sign of value 0), 3-bit "110" (code sequence of (1,1)) and 2-bit "10" (code sequence of register sign of value 2), 1-bit "0" (code sequence of (0,0)) 5-bit "11100" ((0,2) code sequence) and 1-bit "0" (code sequence of register sign of value 0), 3-bit "110" (code sequence of (1,1)) ) And 2 bits of “11” (code sequence of the register sign of value 3), and 5 bits of “11100” (signs of (0, 2)) Since the encoded sequence) and of 1-bit "0" (code sequence register values 0 sign), the code length is 35 (= 7 + 1 + 4 + 5 + 1 + 6 + 5 + 6). The conventional two-dimensional variable length code is 35 bits as shown in FIG.
[0097]
FIG. 17 shows a configuration example of a decoding apparatus that decodes and outputs an acoustic signal from the code string generated by the encoding apparatus of FIG.
[0098]
The code sequence decomposition circuit 41 extracts the code of each signal component from the code sequence 501 that has been transmitted or reproduced from the information recording medium 4, and the signal component decoding circuit 42 extracts the signal component 503 from the code 502. After the decoding, an acoustic waveform signal 504 is generated and output by the inverse conversion circuit 43.
[0099]
FIG. 18 shows a configuration example of the code string decomposition circuit 41.
[0100]
The control unit 51 controls the decoding unit 52 to read the quantized spectrum code sequence (accurately, all positive values) read from the code sequence 601 of the encoding unit input to the code sequence decomposition circuit 41. The code sequence of the quantized spectrum) is decoded.
[0101]
The control unit 51 also reads the plus / minus sign information sign from the code string 601 of the coding unit, detects the plus / minus of the quantized spectrum based on the plus / minus sign information sign, and determines the sign of the signal component.
[0102]
601 in FIG. 18 corresponds to 501 in FIG. 17, and 602 in FIG. 18 corresponds to 502 in FIG.
[0103]
FIG. 19 shows a configuration example of the inverse conversion circuit 43. This corresponds to the conversion circuit 1 of FIG. 9, and the signals 711 and 712 of the respective bands obtained from the signals 701 and 702 by the inverse spectrum conversion circuits 61 and 62 are synthesized by the band synthesis filter 63 to obtain a signal 721. It is made to output. 701 and 702 in FIG. 19 correspond to 503 in FIG. 17, and 721 in FIG. 19 corresponds to 504 in FIG.
[0104]
Next, the operation of the decoding device will be described. The code string decomposition circuit 41 performs a code string decomposition process as shown in the flowchart of FIG.
[0105]
In step S21, the control unit 51 controls the decoding unit 52 to read the quantized spectrums of QSP (0) to QSP (M-1) collected in one group, read from the code string of the encoding unit. A code string (a code string of a quantized spectrum converted to a positive value) is decoded. Note that M is the number of spectrum signals grouped into one group when encoded.
[0106]
In step S22, the control unit 51 determines whether or not all the values obtained by the decoding in step S21 are the values 0. If not, the control unit 51 proceeds to step S23.
[0107]
In step S23, positive / negative code information sign (positive / negative code information sign indicating the positive / negative of the quantized spectrum) input following the code string of the quantized spectrum is read. Details of the processing here are shown in the flowchart of FIG.
[0108]
In step S <b> 31, the control unit 51 initializes the values of the counter i and the register N incorporated therein to the value 0.
[0109]
Next, in step S32, the control unit 51 determines whether or not the value obtained by decoding in step S21 corresponding to QSP (i) is a value 0, and determines that the value is 0. The process proceeds to step S34.
[0110]
On the other hand, when it is determined in step S32 that the value is not 0, the process proceeds to step S33, and the control unit 51 increases the value of the register N by 1, and the process proceeds to step S34.
[0111]
In step S34, the control unit 51 increments the value of the counter i by 1. In step S35, the control unit 51 determines whether or not the value of the counter i is less than the number M of spectrum signals combined into one group. When it determines with it being less than M, it returns to step S32 and performs the process after it.
[0112]
When it is determined in step S35 that the value of the counter i is not less than the number M of spectrum signals (when it is more than that), the process proceeds to step S36, and the control unit 51 performs the step of the code sequence of the encoding unit. From the next bit of the code string read in S21, the code string corresponding to the number of bits of the value of the register N is read as positive / negative code information sign.
[0113]
Thereafter, the process proceeds to step S24 in FIG. 20, and the codes of QSP (0) to QSP (M-1) are determined. Details of the processing here are shown in the flowchart of FIG.
[0114]
In step S41, the control unit 51 initializes the value of the counter i to the value 0, and subtracts 1 from the value of the register N by 1 from the value 1 set in the register mask. Shift to the left by the number of bits.
[0115]
In step S42, the control unit 51 determines whether or not the value obtained by decoding in step S21 corresponding to QSP (i) is the value 0. Proceeding to S43, the logical product of the positive / negative sign information sign read in step S36 and the register mask is calculated, and it is determined whether or not the calculation result is 0.
[0116]
If it is determined in step S43 that the logical product is not 0, the value obtained by decoding in step S21 corresponding to QSP (i) is multiplied by value -1, and the process proceeds to step S45. .
[0117]
On the other hand, if it is determined in step S43 that the logical product is 0, the process of step S44 is skipped and the process proceeds to step S45.
[0118]
In step S45, the control unit 51 shifts the value of the register mask to the right by 1 bit, and proceeds to step S46.
[0119]
If it is determined in step S42 that the value obtained by decoding in step S21 corresponding to QSP (i) is 0, the processing in steps S43 to S45 is skipped and the process proceeds to step S46.
[0120]
In step S46, the control unit 61 increments the value of the counter i by 1. In step S47, the control unit 61 determines whether or not the value of the counter i is less than the number M of spectrum signals collected in one group. If it is determined that it is less than M, the process returns to step S42 and the subsequent processing is executed.
[0121]
If it is determined in step S47 that the value of the counter i is not less than M (if it is greater than or equal to M), the processing in FIG. 20 is completed and then input together with the processing here (processing in step S24). The process after step S1 is similarly performed on the code sequence of the quantized spectrum.
[0122]
Next, the operation of the code string decomposition circuit 41 will be described again by taking as an example the case of decoding the encoded encoding unit shown in FIG.
[0123]
The code string “11110” read first is decoded (step S21) to obtain (1,2). Since (1,2) is not naturally (0,0) (step S22), the positive / negative code information sign “01” input following the code string “11110” is read (step S23).
[0124]
Specifically, in (1,2), the value 1 corresponding to QSP (0) is not the value 0 (step S32), so that the value 0 of the register N is increased by 1 to the value 1 ( In step S33), the value 0 of the counter i is increased by 1 to 1 (step S34).
[0125]
In (1, 2), the value 2 corresponding to QSP (1) is not 0 as well, so the value 1 of the register N is further increased by 1 to 2 and the value 1 of the counter i is 1. Increases to a value of 2.
[0126]
In this case, from the next bit of the code string “11110” of the quantized spectrum, the number of bits of the value 2 of the register N, that is, data “01” for 2 bits is read as the positive / negative code information sign.
[0127]
Next, the codes of QSP (0) and QSP (1) are determined (step S24).
[0128]
Specifically, the value of the counter i is initialized to the value 0, and 1 set in the register mask is shifted leftward by 1 (= value of the register N 2−value 1) bits.
That is, the register mask is (10) (step S41).
[0129]
Since the value 1 corresponding to QSP (0) in (1, 2) is not the value 0 (step S42), the logical product of the sign information sign (01) and the register mask (10) is calculated. Since the calculation result is 0 (step S43), the register mask (10) is shifted rightward by 1 bit to become (01) (step S45). That is, since the value 1 corresponding to QSP (0) was originally a positive value, the value 1 is directly used as the sign of QSP (0).
[0130]
The value 0 of the counter i is incremented by 1 to a value 1 (step S46).
[0131]
Since the value 2 corresponding to QSP (1) in (1, 2) is not the value 0, the logical product of the positive / negative sign information sign (01) and the register mask (01) at this time is calculated, and the calculation result Since the value is 1, the value 2 corresponding to QSP (1) is multiplied by the value −1 to obtain the value −2 (step S44).
[0132]
That is, since the value 2 corresponding to QSP (1) was originally a negative value, it is set to the value −2 as described here, and this is the sign of QSP (1).
[0133]
In this way, the code 502 (FIG. 17) extracted by the code string decomposition circuit 41 is input to the signal component decoding circuit 42 and decoded. The signal component decoding circuit 42 performs processing reverse to that of the signal component encoding circuit 2 shown in FIG.
[0134]
In the signal 503 output from the signal component decoding circuit 42, the spectrum signal component 701 having a lower frequency is input to the inverse spectrum conversion circuit 61, and the spectrum signal component 702 having a higher frequency is input to the inverse spectrum conversion circuit. 62. The inverse spectrum conversion circuits 61 and 62 convert the input spectral signal components 701 and 702 into acoustic signals 711 and 712 on the time axis and output them to the band synthesis filter 63. The band synthesis filter 63 synthesizes a lower frequency acoustic signal 711 and a higher frequency acoustic signal 712 and outputs the synthesized acoustic signal 721 (504).
[0135]
In general, in an acoustic waveform signal, energy is often concentrated on a fundamental frequency and a frequency component that is an integral multiple of the fundamental frequency, that is, a so-called harmonic component, and spectrum signals of other frequency components are often zero even when quantized. The higher the fundamental frequency, the greater the distance between so-called overtone components, so the probability of appearance of a zero quantized spectrum increases. Further, a signal having such a frequency component consumes a considerable amount of information because a sufficient audible signal-to-noise ratio cannot be secured unless quantization is performed with higher quantization accuracy. In particular, a large amount of information is consumed in a wide band of coding units.
[0136]
Therefore, in order to efficiently encode such a signal, it is important to encode the spectrum signal quantized to 0 with a small amount of information. As the most well-known method, there is a method using a multi-dimensional variable length code. However, as described above, a huge amount of code string table is required, which is not practical. However, the method according to the present invention realizes efficient coding without increasing the scale of the code string table.
[0137]
As described above, the band division circuit uses a signal obtained by spectrally converting the signal applied to the band division filter once by MDCT, and the band synthesis circuit is obtained by applying the inverse spectrum conversion by inverse MDCT (IMDCT) to the band synthesis filter. In the above description, the MDCT conversion and the IMDCT conversion may be directly performed without using the band division filter and the band synthesis filter. Further, the type of spectrum conversion is not limited to MDCT, and DFT, DCT, or the like may be used.
[0138]
Furthermore, the band division and the band synthesis may be performed only by the band division filter and the band synthesis filter without necessarily using the spectrum conversion. In this case, a band divided by the filter or a band obtained by collecting a plurality of these bands is set as an encoding unit. However, the method of the present invention can be efficiently applied by performing spectral conversion such as MDCT and converting it into a large number of spectral signals and then configuring the encoding unit as described using the embodiments. .
[0139]
In the above description, the case of processing an acoustic waveform signal has been described. However, the method of the present invention can be applied to other types of signals, for example, an image signal. It is. However, since the present invention realizes efficient encoding when there are a lot of spectral signals quantized to 0 using the characteristics of the acoustic waveform signal, when used for the acoustic waveform signal, Demonstrate power.
[0140]
Further, the method according to the present invention can be used in combination with the conventional variable length code method. For example, when the quantization accuracy is low, that is, when the number of quantization steps is small, encoding is performed using a two-dimensional or four-dimensional code sequence table by a conventional method, and the quantization accuracy is high, that is, the number of quantization steps. If is large, it is more effective to perform encoding using the method according to the present invention in consideration of the scale of the code string table.
[0141]
The series of processes described above can be realized by hardware, but can also be realized by software. When a series of processing is realized by software, a program constituting the software is installed in a computer, and the program is executed by the computer, so that the above-described encoding device and decoding device are functionally realized. Is done.
[0142]
FIG. 23 is a block diagram illustrating a configuration of an embodiment of a computer 101 that functions as the above-described encoding device or decoding device. An input / output interface 116 is connected to a CPU (Central Processing Unit) 111 via a bus 115, and the CPU 111 receives commands from an input unit 118 such as a keyboard and a mouse via the input / output interface 116. When input, it is stored in a recording medium such as a ROM (Read Only Memory) 112, a hard disk 114, or a magnetic disk 131, an optical disk 132, a magneto-optical disk 133, or a semiconductor memory 134 attached to the drive 120, for example. The program is loaded into a RAM (Random Access Memory) 113 and executed. Thereby, the various processes described above (for example, the processes shown in the flowcharts of FIGS. 13 and 20) are performed. Further, the CPU 111 outputs the processing result to the output unit 117 such as an LCD (Liquid Crystal Display) via the input / output interface 116 as necessary. The program is stored in advance in the hard disk 114 or ROM 112 and provided to the user integrally with the computer 101, or provided as a package medium such as the magnetic disk 131, the optical disk 132, the magneto-optical disk 133, or the semiconductor memory 134. Or can be provided to the hard disk 114 via the communication unit 119 from a satellite, a network, or the like.
[0143]
In this specification, the step of describing the program provided by the recording medium is not necessarily performed in time series in parallel with the process performed in time series in the order described, but may be performed in parallel or It also includes processes that are executed individually.
[0144]
【The invention's effect】
According to the encoding apparatus and method, the program of the first recording medium, and the first program of the present invention, the positive / negative of the numerical values are adjusted to unify the positive / negative of the M numerical values. And Calculate the number of numerical values other than the specific value among the M numerical values, and generate information on whether the positive or negative of the numerical value other than the specific value has been adjusted by the number of numerical values other than the calculated specific value. Positive / negative information And positive and negative information Since encoding is performed and a code string including them is generated, for example, encoding with high compression efficiency can be performed without increasing the scale of the code string table.
[0145]
According to the decoding apparatus and method, the program of the second recording medium, and the second program of the present invention, the first and the first encoded in one group by unifying the positive and negative of the numerical values constituting the M numerical value sequences. And a second code string obtained by encoding information for specifying a numerical value whose sign is adjusted when unifying positive and negative are received, the first code string is decoded, 2 code sequence, Calculate the number of numerical values other than the specific value among the M numerical values, and check whether the sign of the numerical value other than the specific value has been adjusted information , Only the number of numerical values other than the calculated specific value Based on the read and decoded numeric sequence with M positive / negative adjusted and the information for specifying the read numeric with adjusted positive / negative, the positive / negative of the M numeric sequence is restored. For example, encoding with high compression efficiency can be performed without increasing the scale of the code string table.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a spectrum of an encoding unit.
FIG. 2 is a diagram illustrating a method for expressing quantization accuracy information.
FIG. 3 is a diagram for explaining an encoding method using a variable-length code according to the prior art.
FIG. 4 is a diagram illustrating an example of a code string table.
FIG. 5 is a diagram for explaining a coding method using a multidimensional variable length code according to the prior art.
FIG. 6 is a diagram illustrating an example of a multidimensional code string table according to a conventional technique.
FIG. 7 is a diagram illustrating an example of another multi-dimensional code string table according to the related art.
FIG. 8 is a diagram illustrating an example of another multi-dimensional code string table according to the related art.
FIG. 9 is a block diagram illustrating a configuration example of an encoding device to which the present invention has been applied.
10 is a block diagram illustrating a configuration example of a conversion circuit in FIG. 9;
11 is a block diagram illustrating a configuration example of a signal component encoding circuit in FIG. 9;
12 is a block diagram illustrating a configuration example of a code string generation circuit in FIG. 9. FIG.
FIG. 13 is a flowchart illustrating the operation of the code string generation circuit.
FIG. 14 is a diagram illustrating an example of a code string table used in the present invention.
FIG. 15 is a diagram illustrating an encoding method according to the present invention.
FIG. 16 is another diagram for explaining a coding method according to the prior art.
FIG. 17 is a block diagram illustrating a configuration example of a decoding device to which the present invention has been applied.
18 is a block diagram illustrating a configuration example of a code string decomposition circuit in FIG. 17;
19 is a block diagram illustrating a configuration example of a conversion circuit in FIG. 17;
FIG. 20 is a flowchart illustrating an operation of a code string decomposition circuit.
FIG. 21 is a flowchart illustrating the process of step S23 of FIG.
FIG. 22 is a flowchart illustrating the process of step S24 of FIG.
23 is a block diagram illustrating a configuration example of a computer 101. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Conversion circuit, 2 Signal component encoding circuit, 3 Code stream generation circuit, 4 Information recording medium, 11 Band division filter, 12 Forward spectrum conversion circuit, 13 Forward spectrum conversion circuit, 21 Normalization circuit, 22 Quantization circuit, 23 Quantization accuracy determination circuit, 31 control unit, 32 encoding unit, 33 encoding unit, 41 code stream decomposition circuit, 42 signal component decoding circuit, 43 inverse transform circuit, 51 control unit, 52 decoding unit, 53 decoding unit, 61, 62 Inverse spectrum conversion circuit, 63 Band synthesis filter

Claims (15)

In an encoding device that encodes the numerical values constituting the numerical sequence in a group of M pieces,
Unifying means for adjusting the positive and negative of the numerical values to unify the positive and negative of the M numerical values;
First encoding means for encoding the numerical value whose positive and negative values are unified by the unifying means;
The number of numerical values other than the specific value among the M numerical values is calculated, and information on whether the sign of the numerical value other than the specific value has been adjusted by the unified means is the number of numerical values other than the calculated specific value. Generating only positive / negative information, and encoding the positive / negative information ;
An encoding apparatus comprising: a code string generation unit that generates a code string including an output of the first encoding unit and an output of the second encoding unit. 2. The encoding according to claim 1, wherein the code string generating unit generates the code string so as to alternately include an output of the first encoding unit and an output of the second encoding unit. apparatus. The encoding apparatus according to claim 1, wherein the first encoding unit encodes the numerical value into a variable-length code string. The encoding apparatus according to claim 3 , wherein the variable-length code string includes a Huffman code. The encoding apparatus according to claim 1, wherein the numerical sequence is a quantized acoustic waveform signal. In the encoding method of the encoding device that encodes the numerical values constituting the numerical sequence in a group of M pieces,
A unified step of adjusting the positive / negative of the numerical values to unify the positive / negative of the M numerical values;
A first encoding step for encoding the numerical value whose sign is unified in the process of the unifying step;
The number of numerical values other than the specific value is calculated among the M numerical values, and information on whether the sign of the numerical value other than the specific value is adjusted in the process of the unifying step is used as the numerical value other than the calculated specific value. A second encoding step for generating positive and negative information and encoding the positive and negative information ;
An encoding method comprising: a code string generation step of generating a code string including an output in the process of the first encoding step and an output in the process of the second encoding step. A program of an encoding device that encodes the numerical values constituting a numerical sequence in a group of M pieces each,
A unified step of adjusting the positive / negative of the numerical values to unify the positive / negative of the M numerical values;
A first encoding step for encoding the numerical value whose sign is unified in the process of the unifying step;
The number of numerical values other than the specific value is calculated among the M numerical values, and information on whether the sign of the numerical value other than the specific value is adjusted in the process of the unifying step is used as the numerical value other than the calculated specific value. A second encoding step for generating positive and negative information and encoding the positive and negative information ;
A computer-readable program comprising: a code string generation step for generating a code string including an output in the process of the first encoding step and an output in the process of the second encoding step. Recording medium on which is recorded. A program of an encoding device that encodes the numerical values constituting a numerical sequence in a group of M pieces each,
A unified step of adjusting the positive / negative of the numerical values to unify the positive / negative of the M numerical values;
A first encoding step for encoding the numerical value whose sign is unified in the processing of the unifying step;
The number of numerical values other than the specific value among the M numerical values is calculated, and information on whether the sign of the numerical value other than the specific value is adjusted in the process of the unifying step is used as the numerical value other than the calculated specific value. A second encoding step for generating positive and negative information and encoding the positive and negative information ;
A computer is caused to execute a process including an output in the process of the first encoding step and a code string generation step of generating a code string including an output in the process of the second encoding step. program. A first code string that is encoded as one group by unifying the sign of the numerical values constituting the M number strings, and information for specifying a numerical value that has been adjusted in sign when the sign is unified. Input means for receiving a code string including the encoded second code string;
Decoding means for decoding the first code string;
Decoding the second code string, and calculates the number of the number other than the specific value of the M number, information about whether the positive and negative numerical values other than the specific value has been adjusted, it was calculated and read-means for reading only the number of numerical value other than the specific value,
A numerical sequence of M negative was adjusted decoded by said decoding means, based on the information for the positive and negative read by the read-means to identify a numerical value which is adjusted, the M numerical sequence A decoding device comprising: restoration means for restoring positive and negative. The decoding apparatus according to claim 9 , wherein the input unit receives a code string including the first code string and the second code string alternately. The read-section, if the specific value is decoded by said decoding means, decoding apparatus according to claim 9, characterized in that not read the second code string. The decoding device according to claim 9 , wherein the specific value is a value of 0. A first code string that is encoded as one group by unifying the sign of the numerical values constituting the M number strings, and information for specifying a numerical value that has been adjusted in sign when the sign is unified. An input step of receiving a code string including the encoded second code string;
A decoding step of decoding the first code string;
Decoding the second code string, and calculates the number of the number other than the specific value of the M number, information about whether the positive and negative numerical values other than the specific value has been adjusted, it was calculated and read-step of reading only the number of numerical value other than the specific value,
Based on the information for the a sequence of numerical values processing the M positive and negative decoded in the decoding step is adjusted, the positive and negative read by the processing of the read-step identifies the numerical value is adjusted, the M And a restoration step for restoring the sign of the numerical sequence of. A first code string that is encoded as one group by unifying the sign of the numerical values constituting the M number strings, and information for specifying a numerical value that has been adjusted in sign when the sign is unified. An input step of receiving a code string including the encoded second code string;
A decoding step of decoding the first code string;
Decoding the second code string, and calculates the number of the number other than the specific value of the M number, information about whether the positive and negative numerical values other than the specific value has been adjusted, it was calculated and read-step of reading only the number of numerical value other than the specific value,
Based on the information for the a sequence of numerical values processing the M positive and negative decoded in the decoding step is adjusted, the positive and negative read by the processing of the read-step identifies the numerical value is adjusted, the M A recording medium on which a computer-readable program is recorded, comprising: a restoring step for restoring the sign of the numerical sequence of A first code string that is encoded as one group by unifying the sign of the numerical values constituting the M number strings, and information for specifying a numerical value that has been adjusted in sign when the sign is unified. An input step of receiving a code string including the encoded second code string;
A decoding step of decoding the first code string;
Decoding the second code string, and calculates the number of the number other than the specific value of the M number, information about whether the positive and negative numerical values other than the specific value has been adjusted, it was calculated and read-step of reading only the number of numerical value other than the specific value,
Based on the information for the a sequence of numerical values processing the M positive and negative decoded in the decoding step is adjusted, the positive and negative read by the processing of the read-step identifies the numerical value is adjusted, the M A program that causes a computer to execute a process including: a restoring step that restores the positive / negative of the numerical sequence of.

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