JP2002182698A - Method and device for encoding and recording medium - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To enable encoding so that quality does not deteriorate. A mixing unit 51-1 and the mixing unit 51-2 mixes band signal A ₀ and the band signal A ₁ and at each predetermined condition. Thus, mutual correlation is higher in the small amplitude portion, since the mixed signal MA ₀ and mixing signals MA ₁ is generated, the band signal A ₀ and the band signal A _1, be encoded such quality does not deteriorate Can be.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an encoding apparatus and method, and a recording medium, and more particularly, to an encoding apparatus and method capable of encoding data so that quality is not deteriorated, and a recording medium. It is.

[0002]

2. Description of the Related Art FIG. 1 shows an example of the configuration of an encoding unit 10 constituting a conventional encoding device.

[0003] The acoustic time-series signal supplied to the encoding unit 10
T is input to the band division unit 11. Band splitting unit 11
Is the input acoustic time-series signal T, as well as divided into two bands, the result band signal A ₀ obtained, the amplitude control unit 12-1, the band signal A _1, the amplitude controller 12
Feed to 2.

The amplitude control unit 12-1 has a configuration as shown in FIG. 2, and the band signal A ₀ supplied to the amplitude control unit 12-1 is transmitted to the amplitude analysis unit 21 and the amplitude operation unit 23. Is entered.

[0005] The amplitude analyzer 21 receives the input band signal A
The amplitude of ₀ is analyzed for each of the sub-blocks into which the block having the coding section length is further divided, and the analysis result is used as the amplitude information.
It outputs to the amplitude operation information generation unit 22 as D. The amplitude operation information generation unit 22 receives the amplitude information D from the amplitude analysis unit 21.
, And generates amplitude operation information G ₀ for making the amplitude of the band signal A ₀ in the block constant, and outputs it to the amplitude operation unit 23 and the quantization accuracy determination unit 16 (FIG. 1).

[0006] The amplitude operation unit 23 includes an amplitude operation information generation unit 2
Based on the amplitude operation information G ₀ from 2, by operating the amplitude of the band signals A ₀ which is input, as the amplitude of the block is constant, it as an object to be amplitude operation signal GA _0, spectrum transform Output to the unit 13-1 (FIG. 1).

For example, a band signal as shown in FIG.
A₀Is supplied to the amplitude control unit 12-1, the amplitude analysis
The unit 21 includes a band signal A₀Is the time T₀Suddenly at
The amplitude information D indicating that the size has increased becomes the amplitude operation information.
The amplitude operation information generation unit 22 outputs
The small-amplitude waveform before time T in the
Amplitude operation information G for making the same as the amplitude₀Generate a
Output to the amplitude operation unit 23 and the quantization accuracy determination unit 16
I do. The amplitude operation unit 23 receives the input band signal A ₀Shake
The width is represented by the amplitude operation information G₀Figure 3
As shown in (B), the amplitudes in the blocks are made the same.

The band signal A ₀ (amplitude operated signal GA ₀ ) having the same amplitude in the block is converted into a frequency component by a spectrum converter 13-1 (FIG. 1) described later, and is normalized. The quantization unit 15-1 normalizes the data in the unit 14-1.
3B, the quantization noise becomes constant as shown in FIG. 3B, and when it is decoded, the quantization noise of the small-amplitude signal portion becomes as shown in FIG. And the occurrence of pre-echo is suppressed.

Returning to FIG. 1, the spectrum converter 13-1
Is constituted by MDCT or the like, to be amplitude operation signal GA ₀ from the amplitude control unit 12-1 is converted into frequency components SP _0, and supplies the normalization unit 14-1.

[0010] The normalizing section 14-1 is provided with a spectrum converting section 1
The frequency component SP ₀ from 3-1 is normalized, and the frequency component SP ₀ is decomposed into a normalization coefficient S ₀ and a normalized signal P ₀ . Normalizing unit 14-1, the normalization coefficient S ₀ to quantization accuracy determining unit 16, and the target normalized signal P _0, is output to the quantization unit 15-1.

The quantization unit 15-1 quantizes the normalized signal P ₀ from the normalization unit 14-1 based on the quantization accuracy information W ₀ from the quantization accuracy determination unit 16, and generates a quantized signal. Q ₀ is generated and output to the code sequence generation unit 17.

The amplitude control unit 12-2 to the quantization unit 15-2
Has the same functions as those of the amplitude control unit 12-1 to the quantization unit 15-1, and a description thereof will be omitted.

The quantization precision determination section 16 includes an amplitude control section 1
2-1 and amplitude operation information G from amplitude control section 12-2
₀ , G ₁ , and normalization coefficients S ₀ , S ₁ from the normalization units 14-1 and 14-2.

[0014] The quantization precision determination section 16 includes a normalization section 14-
Normalization coefficient S from 1₀Based on the quantization accuracy information W₀
Is generated and output to the quantization unit 15-1.
Accuracy information W₀, Amplitude operation information G₀, And the normalization coefficient S
₀Is output to the code string generation unit 17. Quantization accuracy determination unit
16 also indicates the normalization coefficient S from the normalization unit 14-2. ₁To
Based on the quantization accuracy information W₁Is generated, and the quantization unit 15
-2 and the quantization accuracy information W₁, Amplitude control
Product information G₁, And the normalization coefficient S₁To the code string generation unit 17
Output to

The code string generation unit 17 includes a quantization unit 15-
Quantized signal Q ₀ from 1,15-2, Q _1, and the amplitude operation information G _0, G ₁ from the quantization accuracy determination unit 16, normalization coefficient S _0, S _1, and the quantization accuracy information W ₁ , W ₂ are input. The code sequence generation unit 17 sequentially codes these pieces of input information, generates a code sequence C, and outputs the code sequence C to the decoding device.

FIG. 5 shows an example of the configuration of the decoding unit 30 of the decoding device for decoding the code string C generated by the coding unit 10. The code sequence C supplied to the decoding device is input to the code sequence decomposition unit 31 of the decoding unit 30.

The code string decomposing unit 31 receives the input code string C
Is decomposed into quantized signals Q ₀ , Q ₁ , quantization accuracy information W ₀ , W ₁ , normalization coefficients S ₀ , S ₁ , and amplitude operation information G ₀ , G ₁ .

The code stream decomposing unit 31 sends the quantized signal Q ₀ and the quantization accuracy information W ₀ to the inverse quantizing unit 32-1 for normalization coefficient S 0.
₀ to inverse normalization unit 33-1, and the amplitude operation information G ₀ to the amplitude correction unit 35-1, and outputs respectively. The code string decomposing unit 31 also outputs the quantized signal Q ₁ and the quantization accuracy information W ₁ to the inverse quantization unit 32-2, and the normalization coefficient S ₁ to the inverse normalization unit 33-
2, and the amplitude correction unit 35-2 amplitude operation information G ₁
Respectively.

The inverse quantizing section 32-1 is provided with a code string decomposing section 31.
On the basis of the quantization accuracy information W ₀ from the CPU, the quantized signal Q ₀ is inversely quantized to generate (restore) a normalized signal P ₀ and output it to the inverse normalizing unit 33-1.

The inverse normalizing section 33-1 includes a code string decomposing section 31.
Inverse quantization unit 32-1 based on the normalized coefficient S ₀ from
To be normalized signal P ₀ from the inversely normalized frequency component SP ₀ '
Is generated and output to the inverse spectrum section 34-1.

The inverse spectrum unit 34-1 includes an inverse normalization unit 3
The frequency component SP ₀ ′ from 3-1 is subjected to inverse spectrum transformation to generate an amplitude-controlled signal GA ₀ , and the amplitude correction unit 3
Output to 5-1.

The amplitude correction unit 35-1 performs inverse spectrum conversion.
Amplitude operated signal GA from unit 34-1 ₀For the code string
Amplitude operation information G from decomposition section 31₀Operating amplitude, based on
That is, in the encoding unit 10 (the amplitude control unit 12-1)
Band signal A₀'Generate a
Then, the signal is output to the band combining unit 36. Thus, the encoding unit
By performing the amplitude control reverse to the amplitude operation in 10
For example, the band signal A shown in FIG.₀Is encoded and generated
From the code sequence C, a small-amplitude signal as shown in FIG.
Band signal A with partial quantization noise suppressed₀'Is decrypted
It is.

Inverse quantization unit 32-2 to amplitude correction unit 35-
2 is the same as the inverse quantization unit 32-1 through the amplitude operation unit 35-1, and a detailed description thereof will be omitted. However, the amplitude correction unit 35-2 receives the signal from the inverse spectrum conversion unit 34-2. the amplitude operation signal GA _1, amplitude operation based on the amplitude operation information G ₁ from the code string decomposer 31, i.e., by performing the amplitude operation of the amplitude operation opposite in the encoding unit 10 (the amplitude control section 12-2) band The signal A ₁ ′ is generated and output to the band combining unit 36.

The band combining section 36, generates' a, band signal A ₁ from the amplitude correction unit 35-2 'band signal A ₀ from the amplitude correction unit 35-1 was synthesized and the acoustic time-series signal T' Output to an external device.

[0025]

By the way, the encoding unit 1
0 (FIG. 1), the QMF (Quadrature M
irror Filter and PQF (Polyphase Quadrature Filte)
When configured with filters r) or the like, the band divided band signals A ₀ and band signal A ₁ (i.e. signal of the adjacent band), as shown in FIG. 6, for example, the band signals A ₀ for the original frequency components, aliasing band signal a ₁ is generated. Thus, when aliasing occurs,
Correlation of the band signals A ₀ and band signal A ₁ is high.

In this case, the band signal A₀And band signal A₁The
7 (A) and FIG. 7 (B)
As shown in the figure, quantize to the same degree,
And band signal A₀And band signal A₁Of the same degree as the correlation of
Rising quantized signal Q₀And the quantized signal Q₁And generate a code string
If C is generated, it is decoded and the obtained band signal A ₀'
And band signal A₁'To combine that aliasing
Can be canceled.

However, in the encoding unit 30,
Since the band signal A ₀ and the band signal A ₁ are separately quantized, the band signal A ₀ and the band signal A ₁ have high correlation as a whole block, but if the correlation of the small amplitude portion is low, the band signal A ₀ The level of the quantization noise of the quantized signal Q ₀ and the quantized signal Q ₁ generated by each of A ₀ and the band signal A ₁ is:
As shown in FIGS. 8A and 8B, there is a case where they are different. That is, the quantized signal Q ₀ and the quantized signal Q ₁
Sometimes the correlation becomes low. As a result, the band signal A ₀ ′ and the band signal A ₁ ′ obtained by decoding the code string C generated by the quantized signal Q ₀ and the quantized signal Q ₁ are obtained.
Are combined, as shown in FIG. 8 (C), high-level quantization noise remains, and aliasing is not canceled.

FIG. 9 shows another example of the configuration of a conventional encoding device. The encoding device, an acoustic time-series signal T _L is a left signal of the stereo signal is encoded, and the encoding unit 10L for generating a code string C _L, the acoustic time-series signal T _R is a right signal encoded Te, the coding unit 1 for generating a code sequence C _R
0R.

The band division units 11L to 17L of the encoding unit 10L and the band division units 11R to 17R of the encoding unit 10R are arranged in the encoding unit 10L of FIG.
Have the same functions as those of the band division unit 11 to the code sequence generation unit 17, and a detailed description thereof will be omitted. However, in this encoding device, the audio time series signal _TL and the audio time series signal T _R
Are separately encoded to generate a code string C _L and a code string C _R.

The acoustic time-series signal a high correlation as a whole T _L and acoustic time-series signal T _R is the encoding unit 10L and the coder 1
0R, for example, the encoding unit 10
The band signal A divided into bands by the L band dividing unit 11L.
_L0 (FIG. 10A) and the band division unit 1 of the encoding unit 10R.
The band signal A _R0 band-divided by 1R (FIG. 10)
The correlation of (B)) also increases. In this case, as shown in FIG. 10C, their residual energy becomes small.

However, the band signal A_L0And band signal A_R0
Band signal A even if there is a high correlation_R0Of small amplitude
So that the band signal A_L0Waveform different from the small amplitude of
(The part surrounded by a line)
If low, band signal A_L0Of the amplitude control unit 12L-1
The amplitude analysis result (FIG. 11A) and the band signal A_R0of,
The amplitude analysis result by the amplitude controller 12R-1 (FIG. 11)
(B)) become different (each different amplitude operation)
Information G_L0, G_R0Is generated), the band signal A_L0And band signal A _R0
May be subjected to different amplitude operations. What
In FIG. 11, the band signal A_L0And band signal A_R0Dotted line surrounding
Represents a simulation result of the amplitude analysis.

As described above, if different amplitude operations are performed, the resultant amplitude operated signal GA _L0 (FIG. 12)
(A)) and the amplitude operated signal GA _R0 are correlated with the band signal A _L0
And so lower than the correlation between the band signals A _R0, they spectral transformation, normalization, and also low correlation of the quantized signal obtained is quantized Q _L0 and quantized signal Q _R0. As a result, the quantized signal Q _L0 and the quantized signal QR ₀ are shown in FIG.
As shown in (A) and (B), different levels of quantization noise are present.

[0033] That is, such a quantized signal Q _L0 and the quantized signal Q code string generated from _R0 C _L and the code string C _R is acoustic time-series signal obtained decoded respectively T _L 'and acoustic time When the sequence signal T _R ′ is reproduced, for example, there is a problem that the localization of a musical instrument, a sound, or the like becomes unstable.

As described above, the conventional encoding unit 10 has a problem that the audio time-series signal T cannot be encoded so that the sound quality is not degraded.

[0035] FIG. 14 illustrates a configuration example of a decoding apparatus for decoding a code string C _L and the code string C _R generated by the encoding device of FIG.

[0036] The decoding apparatus, the decoding unit 30 for decoding the decoding unit 30L for decoding a code string C _L generated by the encoding unit 10L, the code sequence C _R generated by the encoding unit 10R
R.

The code string decomposing section 31L to the band combining section 36L of the decoding section 30L and the code string decomposing section 3 of the decoding section 30R.
The 1R to band combining unit 36R have the same functions as the code string decomposing unit 31 to the band combining unit 36 of the decoding unit 30 in FIG. 5, and a description thereof will be omitted.

The present invention has been made in view of such circumstances, and it is an object of the present invention to be able to encode an acoustic time-series signal without deteriorating sound quality.

[0039]

An encoding apparatus according to the present invention comprises:
Band dividing means for dividing the input signal into a first band and a second band to generate a signal in the first band and a signal in the second band; A plurality of amplitude operation means for generating a signal to be quantized, and a plurality of quantization means for quantizing the signal to be quantized to generate a quantized signal; And a code string generating means for coding the coded signal to generate a code string, wherein the first amplitude operating means performs the same amplitude operation as the amplitude operation by the second amplitude operating means. First mixing means for mixing a signal in the first band and a signal in the second band under predetermined conditions to generate a mixing signal; and a first amplitude operating means by the second amplitude operating means. The same amplitude operation as the amplitude operation by The second mixing means for mixing the signal of the second band and the signal of the first band under a predetermined condition to generate a mixing signal, and the first amplitude operating means are provided by the first mixing means. The amplitude of the generated mixing signal is analyzed, amplitude operation information is generated based on the analysis result, and the amplitude operation based on the generated amplitude operation information is performed on the mixing signal generated by the first mixing means. , A signal to be quantized, and the second
The amplitude operation means analyzes the amplitude of the mixing signal generated by the second mixing means, generates amplitude operation information based on the analysis result, and performs the amplitude operation based on the generated amplitude operation information in the second Performing on the mixing signal generated by the mixing means to generate a signal to be quantized, the first quantization means quantizes the signal to be quantized generated by the first amplitude operation means, and performs quantization. Generating a signal, the second quantization means quantizes the quantization target signal generated by the second amplitude operation means to generate a quantized signal, and the code string generation means generates the first amplitude operation signal. The amplitude operation information generated by the means and the quantized signal generated by the first quantization means, and the amplitude operation information generated by the second amplitude operation means and the amount generated by the second quantization means The signal respectively encoded, and generating a code string.

The quantization means can normalize the frequency components of the signal to be quantized, generate a normalized signal, and quantize the generated normalized signal.

The quantization means can generate a frequency component by performing spectrum conversion on the signal to be quantized.

The amplitude manipulating means generates amplitude manipulating information for each unit of the spectrum conversion, performs an amplitude manipulating operation on the signal based on the generated amplitude manipulating information, and can generate a signal to be quantized.

The first mixing means or the second mixing means performs the first band signal and the second band signal on the condition based on the correlation between the first band signal and the second band signal. Can be mixed to generate a mixing signal.

The first mixing means or the second mixing means, together with the correlation between the signal of the first band and the signal of the second band to be mixed, the signal of the first band to be mixed and the second signal Under the condition based on the correlation between the signal of the first band and the signal of the second band inputted before or after the signal of the band, the signal of the first band and the signal of the second band to be mixed are mixed. Thus, a mixing signal can be generated.

The first amplitude operating means analyzes the amplitude of the mixing signal generated by the first mixing means,
The amplitude operation information is generated based on the analysis result, the amplitude operation based on the generated amplitude operation information is performed on the signal in the first band, a quantization target signal is generated, and the second amplitude operation means Analyzing the amplitude of the mixing signal generated by the second mixing means, generating amplitude operation information based on the analysis result, and performing the amplitude operation based on the generated amplitude operation information on the signal of the second band. To generate a signal to be quantized.

The apparatus further comprises a plurality of band dividing means and a plurality of code string generating means, wherein the first band dividing means divides the first input signal into a first band and a second band, and A second band signal is generated by dividing the second input signal into a first band and a second band, and the second band signal is divided into a first band signal and a second band signal. And a signal in a second band, and the first mixing means controls the first band so that the first amplitude operation means performs the same amplitude operation as the amplitude operation by the second amplitude operation means. The first band signal generated by the dividing unit and the first band signal generated by the second band dividing unit, or the second band signal generated by the first band dividing unit The signal of the second band generated by the second band dividing means is mixed under predetermined conditions. A mixing signal is generated, and the second mixing means is generated by the second band dividing means so that the amplitude operation by the second amplitude operation means is the same as the amplitude operation by the first amplitude operation means. And a first band signal generated by the first band dividing means.
The signal of the second band or the signal of the second band generated by the second band dividing means and the signal of the second band generated by the first band dividing means are mixed under predetermined conditions, A signal is generated, and the first code string generation means encodes the amplitude operation information generated by the first amplitude operation means and the quantized signal quantized by the first quantization means, and generates a first code string. A code string is generated, and the second code string generation unit encodes the amplitude operation information generated by the second amplitude operation unit and the quantized signal quantized by the second quantization unit, and generates a second code sequence. Can be generated.

[0047] The first mixing means or the second mixing means is provided with the first band splitting means.
Under the condition based on the correlation state between the signal of the second band or the signal of the second band and the signal of the first band or the signal of the second band generated by the second band dividing means. And the first band signal or the second band signal generated by the second band dividing means.
Or the signal of the second band can be mixed to generate a mixed signal.

The first mixing means or the second mixing means comprises: a first band signal or a second band signal generated by the first band dividing means to be mixed; and a second band dividing means. And the correlation state of the signal of the first band or the signal of the second band generated by the first band dividing means and the signal of the first band or the signal of the second band generated by the first band dividing means to be mixed therewith; The first band signal or the second band signal generated by the first band dividing unit input before or after the signal of the first band or the signal of the second band generated by the second band dividing unit. The first band dividing means, which mixes the signal of the band and the signal of the first band or the signal of the second band generated by the second band dividing means under the condition based on the correlation state, Mixing the generated first band signal or the second band signal with the first band signal or the second band signal generated by the second band dividing means to generate a mixed signal can do.

According to the encoding method of the present invention, the input signal is
And a second band, and the signal of the first band and the second band
A plurality of amplitude operation steps for generating a signal of a band, performing an amplitude operation based on predetermined amplitude operation information on a predetermined signal, and generating a signal to be quantized, and a signal to be quantized. And a code sequence generating step of coding the amplitude operation information and the quantized signal to generate a code sequence by quantizing the quantized signal and generating a quantized signal. In the processing of the first amplitude operation step, the signal of the first band and the signal of the second band are predetermined so that the same amplitude operation as the amplitude operation is performed in the processing of the second amplitude operation step. In the first mixing step of mixing under conditions to generate a mixing signal, and in the processing of the second amplitude operation step, an amplitude operation similar to the amplitude operation is performed in the processing of the first amplitude operation step. Second Mixing the signal of the band and the signal of the first band under a predetermined condition to generate a mixing signal, the processing of the first amplitude operation step, and the processing of the first mixing step. The amplitude of the obtained mixing signal is analyzed, amplitude operation information is generated based on the analysis result, and the amplitude operation based on the generated amplitude operation information is performed on the mixing signal generated in the processing of the first mixing step. Is performed, a quantization target signal is generated, and in the process of the second amplitude operation step,
The amplitude of the mixing signal generated in the processing of the second mixing step is analyzed, amplitude operation information is generated based on the analysis result, and the amplitude operation based on the generated amplitude operation information is performed in the second mixing step. This is performed on the mixing signal generated in the processing, a signal to be quantized is generated, and in the processing of the first quantization step, the signal to be quantized generated in the processing of the first amplitude operation step is quantized. Then, a quantized signal is generated, and in the processing of the second quantization step, the signal to be quantized generated in the processing of the second amplitude operation step is quantized to generate a quantized signal. In the processing of the column generation step, the amplitude operation information generated in the processing of the first amplitude operation step, the quantized signal generated in the processing of the first quantization step, and the second
The amplitude operation information generated in the processing of the amplitude operation step and the quantized signal generated in the processing of the second quantization step are respectively encoded to generate a code sequence.

[0050] The program of the recording medium of the present invention comprises a band dividing step of dividing an input signal into a first band and a second band to generate a first band signal and a second band signal; Performing an amplitude operation based on the predetermined amplitude operation information on a predetermined signal to generate a quantization target signal, a plurality of amplitude operation steps, and quantizing the quantization target signal to generate a quantized signal, A method of an encoding apparatus, comprising: a plurality of quantization steps; and a code string generation step of coding amplitude operation information and a quantized signal to generate a code string, wherein the processing of the first amplitude operation step includes: The signal of the first band and the signal of the second band are mixed under a predetermined condition so that an amplitude operation similar to the amplitude operation is performed in the process of the second amplitude operation step, and a mixing signal is generated. One mixing step, In the processing of the second amplitude operation step, the signal of the second band and the signal of the first band are mixed under predetermined conditions so that the same amplitude operation as the amplitude operation is performed in the processing of the first amplitude operation step. Then, in the processing of the second mixing step of generating the mixing signal and the processing of the first amplitude operation step, the amplitude of the mixing signal generated in the processing of the first mixing step is analyzed, and based on the analysis result, Amplitude operation information is generated, an amplitude operation based on the generated amplitude operation information is performed on the mixing signal generated in the processing of the first mixing step, a signal to be quantized is generated, and a second amplitude is generated. In the operation step, the amplitude of the mixing signal generated in the second mixing step is analyzed, and amplitude operation information is generated based on the analysis result. Amplitude operation based on the amplitude operation information, made to the mixing signal generated by the processing of the second mixing step,
A quantization target signal is generated, and in the processing of the first quantization step, the quantization target signal generated in the processing of the first amplitude operation step is quantized to generate a quantized signal. In the processing of the quantization step, the quantization target signal generated in the processing of the second amplitude operation step is quantized to generate a quantized signal. In the processing of the code string generation step, the first amplitude operation step is performed. And the quantized signal generated in the processing of the first quantization step, the amplitude operation information generated in the processing of the second amplitude operation step, and the amplitude operation information generated in the processing of the second quantization step. It is characterized in that each of the quantized signals generated in the processing is encoded and a code string is generated.

In the coding apparatus and method of the present invention, and the program of the recording medium, the input signal is divided into a first band and a second band, and the signal of the first band is divided into the second band and the second band.
Is generated, an amplitude operation based on predetermined amplitude operation information is performed on the predetermined signal, a signal to be quantized is generated, the signal to be quantized is quantized, and the quantized signal is The signal of the first band and the signal of the second band are predetermined so that the generated amplitude operation information and the quantized signal are encoded to generate a code string, and the same amplitude operation as the amplitude operation is performed. Is mixed under the conditions described above to generate a mixing signal, and an amplitude operation similar to the amplitude operation is performed.
The signal of the second band and the signal of the first band are mixed under predetermined conditions, a mixed signal is generated, the amplitude of the generated mixed signal is analyzed, and amplitude operation information is generated based on the analysis result. The amplitude operation based on the generated amplitude operation information is performed on the generated mixing signal, a signal to be quantized is generated, the amplitude of the generated mixing signal is analyzed, and based on the analysis result, Amplitude operation information is generated, an amplitude operation based on the generated amplitude operation information is performed on the generated mixing signal, a quantization target signal is generated, and the generated quantization target signal is quantized. , A quantized signal is generated, the generated signal to be quantized is quantized to generate a quantized signal, the generated amplitude operation information, the generated quantized signal, and the Amplitude operation information and the generated quantized signals are respectively encoded code string are generated.

[0052]

FIG. 15 shows an example of the configuration of an encoding unit 50 constituting an encoding apparatus to which the present invention is applied.
The encoding unit 50 includes the band division unit 11 of the encoding unit 10 of FIG. 1 and the amplitude control units 12-1 and 12-2 (hereinafter, when it is not necessary to distinguish them individually, simply the amplitude control unit 12 A mixing unit 51-1 and a mixing unit 51-2 are provided, respectively. Other parts are the same as those in FIG. 1, and the description thereof will be appropriately omitted.

The mixing section 51-1 includes the band dividing section 1
Both the band signal _A0 and the band signal A1 from _{No. 1} are input respectively. Mixing section 51-2 also has band division section 1
Both the band signal _A0 and the band signal A1 from _{No. 1} are input respectively.

[0054] Mixing unit 51-1, the band signal A ₀ and the band signal A ₁ input, mixes under predetermined conditions, the mixed signal MA ₀ obtained as a result, the output to the amplitude control unit 12-1 I do. Mixing unit 51-2, the band signal A ₀ and the band signal A ₁ input, mixes under predetermined conditions, the mixing signals MA ₁ obtained as a result,
Output to the amplitude controller 12-2.

[0055] Thus, the mixing unit 51-1 and the mixing unit 51-2, the band signal A ₀ and the band signal A ₁ and the respectively so as to mix a predetermined condition,
Also a high correlation with each other in the small amplitude part, it is possible to generate a mixed signal MA ₀ and mixing signals MA _1.

[0056] Mixing signals MA ₀ supplied to the amplitude control unit 12-1, as shown in FIG. 16, the amplitude control unit 12
1 are supplied to the amplitude analysis unit 21 and the amplitude operation unit 23, respectively.

[0057] the amplitude analyzer 21 analyzes the amplitude of the mixing signals MA _0, the amplitude information D as the analysis result, and outputs the amplitude operation information generation unit 22. Amplitude operation information generation unit 22, based on the amplitude information D, to generate an amplitude operation information G _0, and outputs to the amplitude operation section 23 and the quantization accuracy determining unit 16. That is, the amplitude operation information G ₀ based on mixing signals MA ₀ is generated.

The amplitude operation section 23 is an amplitude operation information generation section 2
Based on the amplitude operation information G ₀ from 2, mixed signal MA
The amplitude of ₀ is manipulated, and the resulting amplitude-controlled signal GA ₀
Is output to the spectrum conversion unit 13-1. That is,
The amplitude of the mixing signal MA ₀ is controlled, and the
A ₀ is generated.

The amplitude control unit 12-2 also has an amplitude control unit 12-
1 has the same function as that of FIG.

[0060] Thus, the amplitude control unit 12-1 and the amplitude control unit 12-2. Thus the correlation is high mixing signals MA ₀ and mixing signals MA ₁ is also supplied in the small amplitude portion, a mixing signal The same amplitude operation can be performed on MA ₀ and mixing signal MA ₁ , and as a result, amplitude operated signal GA ₀ and amplitude operated signal GA ₁ having high correlation can be generated.

That is, as a result, the quantized signal Q ₀ and the quantized signal Q ₁ having the same level of quantization noise are generated, so that aliasing occurs in the band signal A ₀ and the band signal A _1. This can also be canceled by band combining at the time of decoding.

FIG. 17 shows a mixing section 51-1 (FIG. 1).
5) and a configuration example of the mixing unit 51-2.

The multiplier 61A of the mixing section 51-1
Multiplies the predetermined value a, the band signal A ₀ that is inputted, the multiplication result is output to the adder 62-1. Multiplier 61B
It is a predetermined value b, and the band signal A ₁ input multiplied, the multiplication result is output to the adder 62-1. Adder 62
-1 adds a signal from the multiplier 61A and the multiplier 61B, the addition result, as a mixed signal MA _0,
Output to the amplitude control unit 12-1.

In the mixing section 51-1, the value a and the value b are used as conditions for mixing, and the band signal _A0 and the band signal
Although A ₁ are mixed, the value a and value b is, for example, 0.
When 5 is a band signal A ₀ and the band signal A ₁ is, it will have been mixed in a ratio of 1: 1.

The multiplier 61C of the mixing section 51-2 has:
Multiplies the predetermined value c, and band signal A ₀ that is inputted, the multiplication result is output to the adder 62-2. Multiplier 61D
It is a predetermined value d, the band signal A ₁ input multiplied, the multiplication result is output to the adder 62-2. Adder 62
-2 adds the signal from the multiplier 61C and multiplier 61D, and outputs the addition result as a mixing signal MA _1, the amplitude control unit 12-2.

In the mixing section 51-2, the value c and the value d are used as conditions for mixing, and the band signal _A0 and the band signal
Although A ₁ are mixed, the value c and value d is, for example, 0.
When 5 is a band signal A ₀ and the band signal A ₁ is, it will have been mixed in a ratio of 1: 1.

[0067] Incidentally, in the example of FIG. 17, the mixing conditions (values a, b, c, d) has had predetermined, the degree of correlation band signal A ₀ and the band signal A ₁ and the like, the condition Can also be changed. FIG. 18 shows a configuration example of a mixing unit 51-1 that can change mixing conditions.

[0068] supplied to the mixing unit 51-1, the band signal A ₀ from the band division unit 11 is input correlation detection unit 71A, a tone / noise determination unit 72A, and the multiplier 74A, respectively. Also, supplied to the mixing unit 51-1, the band signal A ₁ from the band division unit 11, the correlation detection unit 71A, a tone / noise determination unit 72B and the multiplier 7,
4B.

[0069] correlation detection unit 71A calculates the correlation value CR of the band signal A ₀ and the band signal A _1, it is output to a mixing condition determining unit 73A.

The tone / noise determining section 72A outputs the band signal
Whether the energy in the block of A ₀ is uniformly distributed in frequency, that is, whether there is noisy in that part, or whether energy is concentrated in a specific frequency component,
That is, the determination value TN indicating whether the portion has a tone property.
It calculates ₀ and outputs it to the mixing condition determining unit 73A.

The tone / noise determination unit 72B outputs the band signal
Whether the energy in the block of A ₁ is uniformly distributed in frequency, that is, there is noisy in that part, or energy is concentrated in a specific frequency component,
That is, the determination value TN indicating whether the portion has a tone property.
₁ is calculated and output to the mixing condition determining unit 73A.

The mixing condition determining section 73A includes a correlation value CR from the correlation detecting section 71A and a tone / noise determining section 72.
A, a multiplier 7 based on the determination values TN ₀ and TN ₁ from 72B.
A value to be multiplied by band signal A of each of 4A and multiplier 74B (hereinafter, appropriately referred to as a multiplied value) is determined.

More specifically, the mixing condition determining section 73A
Is a predetermined correlation value CR, a judgment value TN₀, And judgment value TN₁To
The corresponding multiplied value of the multiplier 74A and the multiplied value of the multiplier 74B are
Hold the described table (hereinafter, condition table)
, Correlation value CR, judgment value TN ₀, TN₁Has been entered
The corresponding amplification factors from the condition table.
You.

The mixing condition determining section 73A sets the determined mixing conditions (multiplied values of the multipliers 74A and 74B) in the multipliers 74A and 74B.

The multiplier 74A includes a mixing condition determining unit 7
3A and the input band signal A
_It multiplies by ₀ , and outputs the multiplication result to the adder 75A. The multiplier 74B includes a multiplier value set by the mixing condition determination unit 73A, a band signal A ₁ input multiplied, and outputs to the adder 75A.

[0076] The adder 75A adds the signal from the multiplier 74A, the signal from the multiplier 74B, and outputs the addition result as a mixing signal MA _0, the amplitude control unit 12-1.

[0077] For example, (when the correlation value CR is large) when the correlation of the band signals A ₀ and band signal A ₁ is high, the multiplication value of the multiplier and multiplier 74B of the multiplier 74A is 0.5, respectively . That is, the band signal A ₀ and the band signal A ₁ are mixed in a one-to-one.

On the other hand, when the correlation between the band signal A ₀ and the band signal A ₁ is low (when the correlation value CR is small), the multiplied value of the multiplier 74A is, for example, 1, and the multiplied value of the multiplier 74B is 0
It is said. That is, in this case, the mixing unit 51-1
In, the mixing is not substantially performed, and the band signal _A0 is output as it is.

Further, for example, the tone / noise determination unit 72
If the determination value TN ₀ from A indicates that the energy is uniformly distributed in frequency, that is, that there is noise, the mixing condition determination unit 73A sets the multiplication value of the multiplier 74A to 1 And the multiplied value of the multiplier 74B is set to 0. That is, also in this case, the mixing unit 5
In 1-1, the mixing is not performed, and the band signal _A0 is output as it is.

When the band signal A ₀ has noise,
Since the amplitude control is not substantially performed in the amplitude control unit 12-1, the band signal _A0 is quantized as it is in this case.
At the time of decoding, the area sync is masked.

Similarly, when the judgment value TN ₀ from the tone / noise judging section 72 A indicates that energy is concentrated on a specific frequency component, that is, that there is a tone characteristic, the mixing condition is similarly determined. The determining unit 73A sets the multiplied value of the multiplier 74A to 1 and sets the multiplied value of the multiplier 74B to 0.
And That is, in this case, the mixing unit 51-1, the mixing is not performed, the band signal A ₀ is output as it is.

[0082] Incidentally, if there is a tonal band signal A _0,
Since the amplitude control is not substantially performed in the amplitude control unit 12-1, the band signal _A0 is quantized as it is in this case.
Since the amplitude of the signal is constant, the area sync is masked.

Next, the operation of the correlation detecting section 71A of the mixing section 51-1 will be described with reference to the flowchart of FIG.

In step S11, the correlation detecting section 71
A calculates respective sums of the values and the band signal A ₁ value in the band signal A ₀ in the corresponding sub-block, and the difference.

Next, in step S12, the correlation detection unit 71A for all band signals A ₀ and band signal A ₁ of the corresponding the sub-block, and determines whether to calculate their sum and difference , If it is determined that it has not been calculated, the process returns to step S11 and the next band signal A ₀
Calculating the sum and difference of the values and the band signal A ₁ value.

[0086] In step S12, for all the band signal A ₀ and the band signal A ₁ of the corresponding the sub-block, if it is determined that the calculated their sum and difference, the process proceeds to step S13, the correlation detection unit 71A Calculates the sum total SA of the sums calculated in step S11 and the sum total SD of the differences.

Next, in step S14, the correlation detecting section 71A calculates the sum SA calculated in step S13 and the sum SA.
The ratio of SD (= total SA / total SD) is calculated as the correlation value CR,
Output to the mixing condition determining unit 73A.

Thereafter, the process returns to step S11, and the correlation detecting section 71A executes the subsequent processing.

Next, the operation of the tone / noise determining unit 72A of the mixing unit 51-1 will be described with reference to the flowchart of FIG.

[0090] In step S21, the tone / noise determination unit 72A, for band signals A ₀ of the sub-block
Perform FFT transformation and calculate probability distribution.

Next, in step S22, the tone /
The noise determination unit 72A calculates the maximum value _SMAX and the average value _SAVE in the probability distribution calculated in step S21.

In step S13, the tone / noise determining unit 72A calculates the ratio of the maximum value S _MAX to the average value S _AVE (= maximum value S _MAX / average value S _AVE ) as a determination value TN ₀ ,
Output to the mixing condition determining unit 73A.

Thereafter, the flow returns to step S21, and the tone /
The noise determination unit 72A repeatedly executes the subsequent processing.

The tone / noise determining section 72B basically operates in the same manner as the tone / noise determining section 72A, and a description thereof will be omitted.

The mixing section 51-2 (FIG. 15)
Also has basically the same configuration as the mixing section 51-1 and therefore illustration and description thereof are omitted.

In FIG. 15, the acoustic time-series signal
Although the case where T is divided into two bands has been described as an example, it is also possible to divide T into more bands. FIG.
1 shows a configuration example of the encoding unit 50 in the case of dividing into four bands.

[0097] In this case, the mixing unit 51-1, the band signal A _0, and the band signal A ₁ adjacent to the high frequency side is input to the mixing unit 51-2, the band signals A _1, as well as band signal a ₀ and the band signal a ₂ adjacent to the low frequency side and on the high frequency side is input to the mixing unit 51-3, the band signal a _2, and its low-frequency side and the band signal which is adjacent to the high frequency side a ₁ and band signal a ₃ is input, and, in the mixing unit 51 - 4, band signal a ₂ adjacent to the band signal a _3, and its low frequency band is inputted.

Mixing unit 51-1 to mixing unit 5
1-4, the input band signal A, and mixing a predetermined condition, and generates a mixed signal MA ₀ through MA _3, and outputs the amplitude control unit 12-1 to 12-4.

FIG. 22 is a block diagram of the mixing section 51-1 of FIG.
51 to 51-4 show configuration examples. Mixing unit 51
-1 and 51-4 are mixing units 51- in FIG.
Similarly to the configuration of the first and the fifth units 51-2, it is composed of two multipliers 61 and one adder 62.
−2, 51-3 are three multipliers 61 and one adder 6
2 is comprised.

The mixing unit 51-1 shown in FIG.
The mixing conditions are determined in advance for Nos. 51 to 51-4. However, as described above with reference to FIG. 18, the mixing conditions can be changed based on the correlation value and the like. FIG.
21 shows a configuration example of the mixing unit 51-2 in FIG. 21 which can change mixing conditions. The configuration of the mixing units 51-1 and 51-4 at time 21 is the same as that shown in FIG.
8 is the same as that in the mixing section 51-1 of FIG.

The mixing section 51-2 includes two correlation detection sections 71B and 71C, three tone / noise determination sections 72C, 72D and 72E, one mixing condition determination section 73B, and three multipliers 74C and 74D. 74E and one adder 75B.

[0102] correlation detection unit 71B calculates the correlation value CR ₀₁ with band signal A ₀ and the band signal A _1, the correlation detection unit 71C includes a correlation value CR ₁₂ with band signals A ₁ and band signal A ₂ It is calculated and output to the mixing condition determining unit 73B.

The tone / noise determination section 72C outputs the band signal
A determination value TN ₀ of A ₀ is calculated, and a tone / noise determination unit 72D is calculated.
Calculates a determination value TN ₁ band signals A _1, and tone /
Noise determination unit 72E calculates a determination value TN ₂ band signal A _2, and outputs to a mixing condition determiner 73B respectively.

The mixing condition determining unit 73B is configured to determine a multiplier based on the correlation values CR ₀₁ and CR ₁₂ from the correlation detecting units 71B and 71C and the determination values TN _{0 to} TN ₂ from the tone / noise determining units 72C to 72E. The multiplication values of 74C to 74E are determined and set, respectively.

[0105] The multiplier 74C multiplies the multiplied value set, the band signal A ₀ is input, the multiplier 74D multiplies the multiplied value set, the band signal A ₁ input, multiplied The device 74E calculates the set multiplication value and the input band signal A ₂
, And outputs the multiplication results to the adder 75B.

The adder 75B includes multipliers 74C to 74E
Of adding signals input respectively from the addition result as mixing signals MA _1, and outputs the amplitude control unit 12-2.

The mixing section 51-3 also includes the mixing section 5
Since it has the same configuration as 1-2, its illustration and description are omitted.

FIG. 24 shows another example of the configuration of the encoding section 50. This encoding section includes a mixing section 81-1 and a mixing section 81-1 instead of the mixing section 51-1 and the mixing section 51-2 of the encoding section 50 in FIG.
2 are provided.

[0109] The mixing unit 81-1, like the mixing unit 51-1, both band signals A ₀ and band signal A ₁ from the band division section 11 are inputted respectively, to a mixing unit 81-2, Like the mixing unit 51-2, both band signals a ₀ and band signal a ₁ are input.

[0110] Mixing unit 81-1, the band signal A ₀ and the band signal A ₁ input mixes at a predetermined condition,
The resulting mixing signal MA ₀ is transmitted to the amplitude control unit 1.
And outputs to 2-1, the band signal A _0, and outputs it to the amplitude control unit 12-1. Mixing unit 81-2
It is a band signal A ₀ and the band signal A ₁ input mixes at a predetermined condition, a mixing signal MA to the resulting
₁ to the amplitude controller 12-2, and outputs the band signal A
₁ is output to the amplitude controller 12-2 as it is.

As shown in FIG. 25, the mixing signal MA ₀ supplied to the amplitude control unit 12-1 is input to the amplitude analysis unit 21, and the band signal A ₀ is input to the amplitude operation unit 23. . That is, the amplitude operation information G ₀ is generated based on the mixing signal MA ₀ as in the case of the example of FIG. 15, but the amplitude operated signal GA ₀ is generated by performing the amplitude operation on the band signal A _0. You.

In this manner, unnecessary aliasing can be prevented, and a stable amplitude operation can be performed.

FIG. 26 is a block diagram of the mixing section 81-1 of FIG.
And a configuration example of a mixing unit 81-2. The mixing section 81-1 has basically the same configuration as the mixing section 51-1 in FIG.
A ₀ is adapted to be output to the amplitude control unit 12-1.

The mixing unit 81-2 is also basically the same as that shown in FIG.
Has the same configuration as 7 mixing unit 51-2, but adapted to the band signal A ₁ is output to the amplitude control unit 12-2.

FIG. 27 is a block diagram of the mixing section 81-1 of FIG.
2 shows a configuration example in a case where the mixing conditions can be changed. The mixing unit 81-1, basically has the same configuration as the mixing unit 51-1 of FIG. 18, adapted band signal A ₀ is output to the amplitude control unit 12-1 ing. Mixing unit 81-2
Also has a configuration similar to that of the mixing unit 81-1 and therefore illustration and description thereof are omitted.

Note that in FIG. 24, the acoustic time-series signal
Although the case where T is divided into two bands has been described as an example, it is also possible to divide T into more bands. FIG.
8 shows an example of the configuration of the encoding unit 50 when dividing into four bands.

The mixing section 81-1 includes the band signals A ₀ ,
And the band signal A ₁ adjacent to the high frequency side is input to the mixing unit 51-2, the band signals A _1, and the band signal A ₀ and the band signal A ₂ adjacent to the low frequency side and on the high frequency side
There is input to the mixing unit 51-3, the band signal A _2,
As well as the low frequency side and the band signals A ₁ and band signal A ₃ adjacent the back and forth the high band side is input, and, in the mixing unit 51-4 is adjacent to the band signal A _3, and its low-frequency side band signal A ₂ is input.

[0118] Mixing unit 81-1, the band signal A _0, A ₁ input mixes a predetermined condition, and generates a mixed signal MA _0, and outputs the amplitude control unit 12-1, the band signal outputs the a ₀ as the amplitude control unit 12-1. The mixing unit 81-2 receives the input band signal.
A ₀ , A ₁ , and A ₂ are mixed under predetermined conditions to generate a mixing signal MA ₁ , output to the amplitude control unit 12-2, and output the band signal A _{1 as it is} to the amplitude control unit 12-2 I do.

The mixing section 81-3 mixes the input band signals A ₁ , A ₂ , A ₃ under predetermined conditions, generates a mixing signal MA _2, and outputs it to the amplitude control section 12-3. , and outputs a subband signal a ₂ as it is to the amplitude control unit 12-3. Mixing unit 81-4, the band signal A _2, A ₃ input mixes a predetermined condition, and generates a mixed signal MA _3, and outputs the amplitude control unit 12-4, the band signal A ₃ The signal is output to the amplitude controller 12-4 as it is.

FIG. 29 shows another configuration example of the encoding apparatus to which the present invention is applied. This encoding device encodes an acoustic time-series signal _TL that is a left signal of a stereo signal,
An encoding unit 50L for generating a code string C _L, encodes the acoustic time-series signal T _R is a right signal, and a coding unit 50R to generate a code sequence C _R.

The mixing unit 51L of the encoding unit 50L and the band dividing units 11L to the code string generating unit 17L, and the mixing unit 51R of the encoding unit 50R and the band dividing unit 11R to the code string generating unit 17R are arranged as shown in FIG. It has the same functions as the mixing unit 51 of the encoding unit 50 and the band division unit 11 to the code string generation unit 17.

Mixing section 51L-1 of encoding section 50L
The band signal A _L0 from the band division unit 11L, and from the band division portion 11R of the encoding unit 50R, band signal A _L0
An acoustic time-series signal T _R of the corresponding band to the band signal A _R0
Is entered. Mixing unit 51L of encoding unit 50L-
2 includes a band signal A _L1 from the band division unit 11L and a band signal A _L1 from the band division unit 11R of the encoding unit 50R.
Band signal A is an acoustic time-series signal T _R of the band corresponding to the _L1
R1 is input.

Mixing unit 51R-1 of encoding unit 50R
, The band signal A _R0 from the band division unit 11R and the band signal A _L0 from the band division unit 11L of the encoding unit 50L are input. Mixing unit 51R-2 of encoding unit 50R
, The band signal A _R1 from the band division unit 11R and the band signal A _L1 from the band division unit 11L of the encoding unit 50L are input.

Mixing unit 51L-1 of encoding unit 50L
_Mixes the input band signal A _L0 and band signal A _R0 under predetermined conditions, and outputs the resulting mixing signal MA _L0 to the amplitude control unit 12L-1. The mixing unit 51R-1 of the encoding unit 50R mixes the input band signal A _R0 and band signal A _L0 under predetermined conditions, and mixes the resulting mixing signal MA _R0 with the amplitude control unit 12R-1. Output to

As described above, mixing section 51L-1 of encoding section 50L and mixing section 51L of encoding section 50R.
Since R-1 mixes the band signal A _L0 and the band signal A _{R0 under} predetermined conditions, a mixing signal MA _L0 and a mixing signal MA _R0 having a high correlation with each other even in a small amplitude portion are generated. can do.

Mixing unit 51L-2 of encoding unit 50L
Mixes the input band signal A _L1 and band signal A _R1 under predetermined conditions, and outputs the resulting mixing signal MA _L1 to the amplitude controller 12L-2. The mixing unit 51R-2 of the encoding unit 50R mixes the input band signal A _R1 and band signal A _L1 under predetermined conditions, and mixes the resulting mixing signal _MAR1 with the amplitude control unit 12R-2. Output to

As described above, mixing section 51L-2 of encoding section 50L and mixing section 51L of encoding section 50R.
Since R-2 mixes the band signal A _L1 and the band signal A _{R1 under} predetermined conditions, a mixing signal MA _L1 and a mixing signal MA _R1 having a high correlation with each other even in a small amplitude portion are generated. can do.

Mixing signal MA _L0 supplied to amplitude control section 12L-1 of encoding section 50L is supplied to amplitude analysis section 21 and amplitude operation section 23, respectively, as shown in FIG.

The amplitude analyzer 21 analyzes the amplitude of the mixing signal MA _L0 , and outputs amplitude information D as a result of the analysis to the amplitude operation information generator 22. The amplitude operation information generation unit 22 generates amplitude operation information _GL0 based on the amplitude information D, and outputs the amplitude operation information _GLO and the quantization accuracy determination unit 16L.
Output to

The amplitude operation section 23 is provided with an amplitude operation information generation section 2
2 based on the amplitude operation information G _L0 from
A The amplitude of _L0 is manipulated, and the resulting amplitude-controlled signal G
The A _L0, and outputs the orthogonal transform unit 13L-1.

The amplitude controller 12L-2 of the encoder 50L,
And amplitude control units 12R-1 and 12R of encoding unit 50R
-2 also operates in the same manner as the amplitude control unit 12L-1.
The description is omitted.

The sound time-series signal T _L and the sound time-series signal T _R having a high correlation as a whole are generated by the coding section 50L and the coding section 5L.
0R, for example, the band signal A _L0 (FIG. 3) which is band-divided by the band dividing unit 11L of the encoding unit 50L.
1 (A)) and the band signal A _R0 (FIG. 31 (B)) band-divided by the band dividing unit 11R of the encoding unit 50R. Note that, as shown in FIG. 31C, their residual energy is reduced.

In this case, since the mixing signal MA _L0 and the mixing signal MA _R0 have a high correlation even in the small amplitude portion,
The amplitude control unit 12L-1 of the encoding unit 50L and the encoding unit 50
In the R amplitude control unit 12R-1, the mixing signal
The result of the amplitude analysis of MA _L0 (FIG. 32 (A)) and the result of the amplitude analysis of mixing signal A _R0 (FIG. 32 (B)) are the same.
That is, the same amplitude operation is performed on mixing signal MA _L0 and mixing signal _MAR0 .

[0134] Thus, the same amplitude operation is performed, the resulting, the amplitude operation signal GA _R0 of the amplitude operation signal GA _L0 and encoding unit 50R of the encoding unit 50L, the bandwidth signal A _Since the correlation between _{L 0} and the band signal A _R0 is substantially the same, the correlation between the quantized signal Q _L0 and the quantized signal QR ₀ obtained by subjecting them to spectral transformation, normalization, and quantization is similarly _calculated. Get higher. That is, the quantized signal Q _L0 and the quantized signal Q
_R0 has the same level of quantization noise.

As a result, such a quantized signal Q _L0 and a code sequence C _L and a code sequence C generated from the quantized signal QR _{0 are obtained.
When} the audio time-series signal T _L ′ and the audio time-series signal T _R ′ obtained by decoding _R are reproduced, the localization of a musical instrument, voice, or the like can be stably heard.

FIG. 33 shows a mixing section 51L-1 of the encoding section 50L and a mixing section 51R- of the encoding section 50R.
1 shows a configuration example.

Mixing unit 51L-1 of encoding unit 50L
Is multiplied by a predetermined multiplied value al and the input band signal A _L0, and the result of the multiplication is added to the adder 62L
Output to -1. The multiplier 61BL outputs a predetermined multiplied value bl
And the input band signal A _R0 , and outputs the multiplication result to the adder 62L-1. Adder 62L-1
Adds the signals from the multipliers 61AL and 61BL, and calculates the addition result as a mixing signal MA _L0 .
Output to the amplitude control unit 12L-1.

Mixing section 51R-1 of encoding section 50R
Is multiplied by a predetermined multiplied value cr and the input band signal A _L0 , and the multiplied result is added to an adder 62R
Output to -1. The multiplier 61DR outputs a predetermined multiplied value dr.
And the input band signal A _R0 , and outputs the multiplication result to the adder 62R-1. Adder 62R-1
Adds the signal from the multiplier 61CR and multiplier 61dR, the addition result, as a mixed signal MA _R0,
Output to the amplitude control unit 12R-1.

In the example of FIG. 33, the mixing conditions are predetermined, but the band signal A _L0 and the band signal A
The condition can also be changed according to _R0 or the degree of correlation between the band signal A _L1 and the band signal A _R1 . FIG. 34 shows a configuration example of the mixing unit 51L-1 when the mixing conditions can be changed.

The mixing section 51L-1 is different from the mixing section 51-1 in FIG.
A, 72B has been removed. That is, based on the mixing condition based on the correlation value CR between the band signal A _L0 and the band signal A _R0 , the band signal A _L0 and the band signal A _R0
Are mixed.

For example, when the correlation between the band signal A _L0 and the band signal A _R0 is high (when the correlation value CR is large), the multiplication value of the multiplier 74A and the multiplication value of the multiplier 74B are 0.5
It is said. That is, the band signal A _L0 and the band signal A _R0 are mixed one-to-one. On the other hand, band signal A _L0 and band signal A
_When the correlation of _R0 is low (when the correlation value CR is small), the multiplier of the multiplier 74A is set to 1, for example, and the multiplier of the multiplier 74B is set to 0. That is, the mixing unit 51L
At -1, no mixing is performed and the band signal A _L0
Is output as is.

Mixing units 51L-2, 51R-1, 5
1R-2 also has basically the same configuration as the mixing section 51L-1, and a description thereof will be omitted.

FIG. 35 shows another example of the structure of the mixing section 51L-1 when the mixing conditions can be changed. This mixing unit includes a buffer 101L and a buffer 101L in the mixing unit 51L-1 of FIG.
R, a buffer 102L, a buffer 102R, a correlation value holding unit 103, and a correlation value holding unit 104 are further provided.

The buffer 101L receives the input band signal.
A_L0And newly store the band signal A for the sub-block._L0But
Band signal A held when input_L0The buff
Output to the printer 102L. The buffer 101R receives the input
Band signal A_R0And a new sub-block
Area signal A_R0Is input, the band signal A held _R0
Is output to the buffer 102R.

The buffer 102L stores the band signal A _L0 from the buffer 101L, and newly stores the buffer 101L.
Then, when the band signal A _L0 is input, the held band signal A _L0 is output to the multiplier 74A. Buffer 10
2R stores band signal A _R0 from the buffer 101R, fresh from the buffer 101R, when the band signal A _R0 is input, a band signal A _R0 that held multiplier 7
Output to 4B.

The correlation detecting section 71A receives the input band signal.
A correlation value CR between A ₀ and band signal A ₁ is calculated, and is output to correlation value holding section 103.

The correlation value holding section 103 includes a correlation detecting section 71A.
And when the correlation value CR is newly supplied from the correlation detection unit 71A, the held correlation value CR is output to the mixing condition determination unit 73A and the correlation value holding unit 104. I do.

The correlation value holding unit 104 includes the correlation value holding unit 10
3 is held, and when a new correlation value CR is supplied from the correlation value holding unit 103, the held correlation value CR is output to the mixing condition determination unit 73A.

That is, in the case of this example, the buffer 102
The mixing conditions of the band signal A _L0 from _L (hereinafter, referred to as a center band signal A _L0 ) and the band signal A _R0 from the buffer 102R (hereinafter, referred to as a center band signal A _R0 ) are as follows:
Correlation value CR between center band signal A _L0 and center band signal A _R0 , correlation value between center band signal A _L0 and center band signal A _R0, and band signal A _L0 and band signal A _R0 of the _immediately preceding sub-block It is determined based on the CR, and the correlation value CR between the center band signal A _L0 and the center band signal A _R0, and the band signal A _L0 and the band signal A _R0 of the _immediately subsequent sub-block.

FIG. 36 shows another configuration example of the encoding unit 50L and the encoding unit 50R. This encoding unit 50L
The mixing unit 51L- of the encoding unit 50L in FIG.
1, a mixing unit 81L-1 and a mixing unit 81L-2 are provided instead of the mixing unit 51L-2. The encoding unit 50R includes the encoding unit 5 shown in FIG.
OR mixing section 51R-1 and mixing section 51
A mixing unit 81R-1 and a mixing unit 81R-2 are provided instead of R-2.

That is, the mixing unit 81L-1 of the encoding unit 50L outputs the input band signal A _L0 and band signal A
_R0 is mixed under predetermined conditions, and the resulting mixed signal MA _L0 is output to the amplitude control unit 12L-1 and the band signal A _L0 is output to the amplitude control unit 12L-1 as it is. The mixing unit 81L-2 mixes the input band signal A _L1 and band signal A _R1 under predetermined conditions, and outputs the resulting mixing signal MA _L1 to the amplitude control unit 12L-2. The signal A _L1 is directly output to the amplitude control unit 12L-2.

Mixing unit 81R-1 of encoding unit 50R
_Mixes the input band signal A _R0 and band signal A _L0 under predetermined conditions, and obtains the resulting mixed signal.
MA _{R 0} is output to amplitude control section 12R-1, and band signal A _R0 is output to amplitude control section 12R-1 as it is. Mixing section 81R-2 mixes input band signal A _R1 and band signal A _L1 under predetermined conditions, and mixes resulting mixing signal MA _R1 in amplitude control section 12R-2.
And outputs the band signal _AR1 to the amplitude controller 12R-2 as it is.

The mixing signal MA _L0 supplied to the amplitude controller 12L-1 of the encoder 50L is input to the amplitude analyzer 21 as shown in FIG. 37, and the band signal A _L0 is
It is input to the amplitude operation unit 23. That is, amplitude operation information
G _L0 is the mixing signal MA as in the example of FIG.
_Although it is generated based on _L0 , the amplitude operated signal GA _L0 is generated by amplitude-manipulating the band signal A _L0 .

FIG. 38 is a diagram showing a mixing section 81L- in FIG.
1 and a configuration example of the mixing unit 81R-1. This mixing unit 81L-1 basically has the configuration shown in FIG.
Has the same configuration as that of the mixing section 51L-1, but the band signal A _L0 is directly output to the amplitude control section 12L-1.

The mixing section 81R-1 has basically the same configuration as the mixing section 51R-1 in FIG. 33, but the band signal A _R0 is used as it is in the amplitude control section 12R-1.
To be output.

The mixing units 81L-2 and 81R-2 also
Since it has the same configuration as the mixing units 81L-1 and 81R-1, its illustration and description are omitted.

FIG. 39 is a diagram showing a mixing section 81L- shown in FIG.
1 shows a configuration example in a case where a mixing condition can be changed. The mixing unit 81L-1 has basically the same configuration as the mixing unit 51-1 in FIG. 34, but the band signal A _L0 is directly used as the amplitude control unit _12L.
L-1.

Mixing units 81L-2, 81R-1, 8
1R-2 also has a configuration similar to that of the mixing unit 81L-1, so that illustration and description thereof are omitted.

FIG. 40 is a diagram showing a mixing section 81L-
1 shows another configuration example where the mixing condition can be changed. This mixing unit 81L-1
Has basically the same configuration as the mixing section 51L-1 in FIG. 35, but the band signal A _L0 is directly output to the amplitude control section 12L-1.

The above-described series of processing 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 unit 50 is functionally realized. .

FIG. 41 is a block diagram showing the configuration of an embodiment of a computer 501 functioning as the above-described encoding unit. CPU (Central Processing Unit) 5
11 has an input / output interface 51 via a bus 515.
When a user inputs a command from an input unit 518 including a keyboard and a mouse via the input / output interface 516, the CPU 511, for example, reads a ROM (Read Only Memory) 512, a hard disk 514, Alternatively, a magnetic disk 531, an optical disk 532, a magneto-optical disk 533 mounted on the drive 520,
Alternatively, a program stored in a recording medium such as a semiconductor memory 534 is stored in a RAM (Random Access Memory) 5.
13 and executed. Thereby, the various processes described above are performed. Further, the CPU 511 transmits the processing result via, for example, the input / output interface 516.
Display unit 5 such as LCD (Liquid Crystal Display)
Output to 17 as needed. The program is stored in the hard disk 514 or the ROM 512 in advance,
Provided to the user integrally with the computer 501, provided as package media such as the magnetic disk 531, the optical disk 532, the magneto-optical disk 533, and the semiconductor memory 534;
9 to the hard disk 514.

In this specification, the step of describing a program provided by a recording medium may be performed not only in chronological order according to the described order, but also in chronological order. This also includes processing executed in parallel or individually.

In the present specification, the system is
It represents the entire device composed of a plurality of devices.

[0164]

According to the encoding apparatus and method of the present invention and the program of the recording medium, the input signal is divided into a first band and a second band, and the signal of the first band is Generate a signal of the band, perform an amplitude operation based on the predetermined amplitude operation information on a predetermined signal, generate a quantization target signal, quantize the quantization target signal, generate a quantized signal Encode the amplitude operation information and the quantized signal, generate a code sequence, and perform the same amplitude operation as the amplitude operation.
The signal of the first band and the signal of the second band are mixed under a predetermined condition to generate a mixing signal, and the signal of the second band and the first signal are mixed so that the amplitude operation similar to the amplitude operation is performed. Is mixed under predetermined conditions to generate a mixing signal, analyze the amplitude of the generated mixing signal, generate amplitude operation information based on the analysis result, and generate the amplitude operation information based on the generated amplitude operation information. Performing an amplitude operation on the generated mixing signal, generating a signal to be quantized, analyzing the amplitude of the generated mixing signal, generating amplitude operation information based on the analysis result, and generating the generated amplitude signal. Performing an amplitude operation based on the operation information on the generated mixing signal, generating a quantization target signal, quantizing the generated quantization target signal, generating a quantized signal, and generating the generated quantization. Quantizing the elephant signal to generate a quantized signal, encoding the generated amplitude operation information and the generated quantized signal, and the generated amplitude operation information and the generated quantized signal, respectively, Since the generation is performed, for example, generation of noise can be suppressed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of an encoding unit 10 included in a conventional encoding device.

FIG. 2 is a block diagram illustrating a configuration example of an amplitude control unit 12-1 in FIG. 1;

FIG. 3 is a diagram illustrating an operation of an encoding unit 10;

FIG. 4 is a diagram illustrating a decoding result.

FIG. 5 is a block diagram illustrating a configuration example of a decoding unit 30 included in a conventional decoding device.

FIG. 6 is a diagram illustrating aliasing.

FIG. 7 is another diagram illustrating aliasing.

FIG. 8 is a diagram illustrating cancellation of aliasing.

FIG. 9 is a block diagram illustrating another configuration example of a conventional encoding device.

FIG. 10 is a diagram illustrating the operation of an encoding unit 10L and an encoding unit 10R.

FIG. 11 is another diagram illustrating the operation of the encoding unit 10L and the encoding unit 10R.

FIG. 12 is another diagram illustrating the operation of the encoding unit 10L and the encoding unit 10R.

FIG. 13 is another diagram illustrating the operation of the encoding unit 10L and the encoding unit 10R.

FIG. 14 is a block diagram illustrating a configuration example of a conventional decoding device.

FIG. 15 is a block diagram illustrating a configuration example of an encoding unit 50 to which the present invention has been applied.

16 is a block diagram illustrating a configuration example of an amplitude control unit 12-1 in FIG.

17 is a block diagram illustrating a configuration example of mixing units 51-1 and 51-2 in FIG.

18 is a block diagram illustrating another configuration example of the mixing unit 51-1 in FIG.

FIG. 19 is a flowchart illustrating the operation of a correlation detection unit 71A.

FIG. 20 is a flowchart illustrating the operation of a tone / noise determination unit 72A.

FIG. 21 is a block diagram illustrating a configuration example of an encoding unit when dividing an audio time-series signal into four bands.

FIG. 22 shows mixing units 51-1 to 51-4 in FIG.
FIG. 3 is a block diagram illustrating a configuration example of FIG.

FIG. 23 is a block diagram illustrating another configuration example of the mixing unit 51-2 in FIG. 21;

FIG. 24 is a block diagram illustrating another configuration example of the encoding unit 50.

25 is a block diagram illustrating a configuration example of an amplitude control unit 12-1 in FIG. 24.

26 is a block diagram illustrating a configuration example of mixing units 81-1 and 81-2 in FIG.

FIG. 27 is a block diagram illustrating another configuration example of the mixing unit 81-1 of FIG. 24;

FIG. 28 is a block diagram illustrating another configuration example of the encoding unit 50 in a case where an acoustic time-series signal is divided into four bands.

FIG. 29 is a block diagram illustrating another configuration example of an encoding device to which the present invention has been applied.

30 is a block diagram illustrating a configuration example of an amplitude control unit 12L-1 in FIG. 29.

FIG. 31 is a diagram illustrating operations of the encoding unit 50L and the encoding unit 50R.

FIG. 32 is a diagram illustrating operations of the encoding unit 50L and the encoding unit 50R.

FIG. 33 shows mixing portions 51L-1, 51R- in FIG.
1 is a block diagram illustrating a configuration example of FIG.

34 is a block diagram illustrating another configuration example of the mixing unit 51L-1 of FIG. 29.

35 is a block diagram illustrating another configuration example of the mixing unit 51L-1 in FIG. 29.

FIG. 36 is a block diagram illustrating another configuration example of an encoding device to which the present invention has been applied.

FIG. 37 is a block diagram illustrating a configuration example of an amplitude control unit 12L-1 in FIG. 36.

FIG. 38 shows mixing portions 81L-1, 81R- of FIG.
1 is a block diagram illustrating a configuration example of FIG.

39 is a block diagram illustrating another configuration example of the mixing unit 81L-1 of FIG. 36.

40 is a block diagram illustrating another configuration example of the mixing unit 81L-1 of FIG. 36.

FIG. 41 is a block diagram illustrating a configuration example of a computer 501.

[Explanation of symbols]

11 band division unit, 12 amplitude control unit, 13 spectrum conversion unit, 14 normalization unit, 15 quantization unit,
16 quantization precision determination unit, 17 code string generation unit, 2
1 Amplitude analysis unit, 22 Amplitude operation information generation unit, 23
Amplitude manipulator, 50 encoder, 51 mixing unit, 61 multiplier, 62 adder, 71 correlation detector, 72 tone / noise determiner, 73 mixing condition determiner, 74 multiplier, 75 adder,
81 mixing unit, 101 buffer, 102 buffer, 103 correlation value holding unit, 104 correlation value holding unit

Continuation of the front page (72) Inventor Minoru Tsuji 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo F-term in Sony Corporation (reference) 5D045 DA11 5J064 AA05 BB12 BC02 BC16 BC17 BC18 BD02 5K041 AA04 EE31 HH01

Claims (12)

[Claims] 1. Band splitting means for splitting an input signal into a first band and a second band to generate a signal in the first band and a signal in the second band; A plurality of amplitude operation means for performing an amplitude operation based on a predetermined signal to generate a signal to be quantized, and quantizing the signal to be quantized to generate a quantized signal; Means, and a code string generating means for coding the amplitude operation information and the quantized signal to generate a code string, wherein the first amplitude operating means is used for the second amplitude operating means. A first mixing unit that mixes the signal of the first band and the signal of the second band under a predetermined condition so as to perform the amplitude operation similar to the amplitude operation according to the first embodiment, and generates a mixing signal. And the second amplitude manipulator Thus, the signal of the second band and the signal of the first band are mixed under a predetermined condition so that the amplitude operation similar to the amplitude operation by the first amplitude operation means is performed. A second mixing unit that generates a signal; and the first amplitude operation unit analyzes an amplitude of the mixing signal generated by the first mixing unit.
Generating the amplitude operation information based on the analysis result; performing the amplitude operation based on the generated amplitude operation information on the mixing signal generated by the first mixing unit; The second amplitude operation means analyzes the amplitude of the mixing signal generated by the second mixing means,
Generating the amplitude operation information based on the analysis result; performing the amplitude operation based on the generated amplitude operation information on the mixing signal generated by the second mixing unit; The first quantization means quantizes the signal to be quantized generated by the first amplitude operation means to generate the quantized signal, and the second quantization means Quantizing the signal to be quantized generated by the second amplitude manipulating means to generate the quantized signal, wherein the code string generating means comprises: the amplitude generated by the first amplitude manipulating means. The operation information, the quantized signal generated by the first quantization means, the amplitude operation information generated by the second amplitude operation means, and the amplitude signal generated by the second quantization means. It said quantized signal respectively Coding, coding apparatus and generates the code string. 2. The quantization means generates a normalized signal by normalizing a frequency component of the signal to be quantized.
The encoding apparatus according to claim 1, wherein the generated normalized signal is quantized. 3. The encoding apparatus according to claim 2, wherein said quantization means performs spectrum conversion on said signal to be quantized to generate said frequency component. 4. The amplitude operation means generates the amplitude operation information for each unit of spectrum conversion, performs an amplitude operation based on the generated amplitude operation information on the mix signal, and The encoding device according to claim 3, wherein the encoding device generates a signal. 5. The first mixing means or the second mixing means, wherein the condition based on the correlation between the signal of the first band and the signal of the second band, the signal of the first band 2. The encoding apparatus according to claim 1, wherein a signal is mixed with a signal in the second band to generate the mixed signal. 6. The first mixing means or the second mixing means, together with a correlation state between the signal of the first band and the signal of the second band to be mixed, and the first mixing means to be mixed therefrom. The first band to be mixed under the condition based on the correlation between the signal of the first band and the signal of the second band inputted before or after the signal of the band and the signal of the second band And the signal of the second band are mixed,
The encoding device according to claim 1, wherein the encoding signal is generated. 7. The first amplitude operation means analyzes the amplitude of the mixing signal generated by the first mixing means, generates the amplitude operation information based on the analysis result, and generates the amplitude operation information. The amplitude operation based on the amplitude operation information is performed on the signal in the first band to generate the signal to be quantized. The second amplitude operation unit is generated by the second mixing unit. Analyzing the amplitude of the mixing signal,
Generating the amplitude operation information based on the analysis result, performing the amplitude operation based on the generated amplitude operation information on the signal of the second band, and generating the quantization target signal. The encoding device according to claim 1, wherein: 8. The apparatus further comprising a plurality of band dividing means and a plurality of code string generating means, wherein the first band dividing means converts the first input signal into the first band and the second band. Dividing to generate a signal of the first band and a signal of the second band, wherein the second band dividing means divides a second input signal into a signal of the first band and a signal of the second band. Dividing the signal into bands and generating a signal in the first band and a signal in the second band, wherein the first mixing means is provided by the first amplitude operation means and by the second amplitude operation means The first band signal generated by the first band dividing unit and the first band generated by the second band dividing unit so that the same amplitude operation as the amplitude operation is performed. Or the second band generated by the first band dividing means. Mixing the signal of the band and the signal of the second band generated by the second band dividing means under a predetermined condition to generate the mixing signal, wherein the second mixing means A signal of the first band generated by the second band splitting means so that the amplitude operation similar to the amplitude operation by the first amplitude operating means is performed by the amplitude operating means. The first band signal generated by the first band dividing unit, or the second band signal generated by the second band dividing unit and the second band signal generated by the first band dividing unit. The signal of the second band is mixed under a predetermined condition to generate the mixing signal, and the first code string generation unit includes the amplitude operation information generated by the first amplitude operation unit and the second One Encoding the quantized signal quantized by the decoding means to generate a first code string; and a second code string generation means configured to generate the first code string by using the amplitude generated by the second amplitude operation means. The encoding apparatus according to claim 1, wherein the operation information and the quantized signal quantized by the second quantization unit are encoded to generate a second code string. 9. The first mixing means or the second mixing means, wherein the first band signal or the second band signal generated by the first band division means is connected to the second band signal and the second band signal. Under the condition based on the correlation state of the signal of the first band or the signal of the second band generated by the second band dividing means, the first band generated by the first band dividing means. Mixing the signal or the signal of the second band with the signal of the first band or the signal of the second band generated by the second band dividing means to generate the mixed signal. The encoding device according to claim 8, characterized in that: 10. The first mixing means or the second mixing means, wherein the signal of the first band or the signal of the second band generated by the first band dividing means to be mixed is , Together with the correlation state of the signal of the first band or the signal of the second band generated by the second band dividing means, and the first band generated by the first band dividing means mixing therefrom. Band signal or the second band signal, and the first band signal generated by the second band dividing means or the first band signal input before or after the second band signal. A signal of the first band or the signal of the second band generated by the band dividing means, and a signal of the first band or the second signal generated by the second band dividing means. The signal of the first band or the signal of the second band generated by the first band dividing means to be mixed therefrom under the condition based on the correlation state of the signal of the band of the second band 9. The encoding apparatus according to claim 8, wherein the signal of the first band or the signal of the second band generated by the means is mixed to generate the mixed signal. 11. A band dividing step of dividing an input signal into a first band and a second band, and generating a signal of the first band and a signal of the second band; Performing an amplitude operation on a predetermined signal to generate a signal to be quantized, a plurality of amplitude operation steps, and quantizing the signal to be quantized to generate a quantized signal. And a code string generating step of coding the amplitude operation information and the quantized signal to generate a code string. In the coding method of the coding apparatus, 2 so that the amplitude operation similar to the amplitude operation is performed in the processing of the amplitude operation step 2
Mixing a signal in a predetermined band under a predetermined condition to generate a mixing signal; and, in the processing in the second amplitude operation step, the amplitude operation in the processing in the first amplitude operation step. The signal of the second band and the first signal are controlled so that the same amplitude operation is performed.
A second mixing step of mixing a signal in a band of a predetermined condition to generate a mixing signal; The amplitude of the signal is analyzed, the amplitude operation information is generated based on the analysis result, and the amplitude operation based on the generated amplitude operation information is performed by the mixing signal generated in the processing of the first mixing step. Is performed, and the signal to be quantized is generated. In the processing of the second amplitude operation step, the amplitude of the mixing signal generated in the processing of the second mixing step is analyzed. The amplitude operation information is generated based on the amplitude operation information, and the amplitude operation based on the generated amplitude operation information is performed by the second mixing step. Is performed on the mixing signal generated in the processing of the loop, the signal to be quantized is generated, and in the processing of the first quantization step, the signal generated in the processing of the first amplitude operation step is generated. The quantization target signal is quantized to generate the quantized signal. In the second processing of the quantization step, the quantization target signal generated in the processing of the second amplitude operation step is quantized. Then, the quantized signal is generated, and the amplitude operation information generated in the process of the first amplitude operation step and the amplitude operation information generated in the process of the first quantization step are generated in the process of the code sequence generation step. The quantized signal, the amplitude operation information generated in the processing of the second amplitude operation step, and the quantized signal generated in the processing of the second quantization step are respectively encoded. , Wherein the code sequence is generated. 12. A band dividing step of dividing an input signal into a first band and a second band, and generating a signal of the first band and a signal of the second band; Performing an amplitude operation on a predetermined signal to generate a signal to be quantized, a plurality of amplitude operation steps, and quantizing the signal to be quantized to generate a quantized signal. And a code string generating step of coding the amplitude operation information and the quantized signal to generate a code string, wherein the processing of the first amplitude operation step includes: 2 so that the amplitude operation similar to the amplitude operation is performed in the processing of the amplitude operation step of 2.
Mixing a signal in a predetermined band under a predetermined condition to generate a mixing signal; and, in the processing in the second amplitude operation step, the amplitude operation in the processing in the first amplitude operation step. The signal of the second band and the first signal are controlled so that the same amplitude operation is performed.
A second mixing step of mixing a signal in a band of a predetermined condition to generate a mixing signal; The amplitude of the signal is analyzed, the amplitude operation information is generated based on the analysis result, and the amplitude operation based on the generated amplitude operation information is performed by the mixing signal generated in the processing of the first mixing step. Is performed, and the signal to be quantized is generated. In the processing of the second amplitude operation step, the amplitude of the mixing signal generated in the processing of the second mixing step is analyzed. The amplitude operation information is generated based on the second mixing step based on the generated amplitude operation information. Is performed on the mixing signal generated in the processing of the loop, the signal to be quantized is generated, and in the processing of the first quantization step, the signal generated in the processing of the first amplitude operation step is generated. The quantization target signal is quantized to generate the quantized signal. In the second processing of the quantization step, the quantization target signal generated in the processing of the second amplitude operation step is quantized. Then, the quantized signal is generated, and the amplitude operation information generated in the process of the first amplitude operation step and the amplitude operation information generated in the process of the first quantization step are generated in the process of the code sequence generation step. The quantized signal, the amplitude operation information generated in the processing of the second amplitude operation step, and the quantized signal generated in the processing of the second quantization step are respectively encoded. And a computer-readable recording medium on which the code string is generated.