CN101604983B - Device, system and method for coding and decoding - Google Patents

Abstract

The embodiment of the invention provides a device, a system and a method for coding and decoding, which are applied to a stereo signal. The method comprising the following steps: acquiring a stereo parameter of the stereo signal to be coded, which is converted in an MDCT field, and performing quantification processing on the stereo parameter; downwards mixing the stereo signal into a signal-channel signal code; compounding and sending the quantified stereo parameter and a coded signal; decoding and compounding the data to be decoded into the stereo parameter and the coded signal; decoding and quantifying the stereo parameter; decoding the coded signal into a single-channel signal; acquiring decorrelation signals of the single-channel signal in the MDCT field; and synthesizing and restoring the quantified stereo parameter, the single-channel signal and the decorrelation signals to the stereo signal. The device, the system and the method for coding and decoding are used for coding stereo and can solve the problem how to obtain two paths of left and right channel stereo signals by one path of signal-channel signal at a decoding end and realize stereo coding and decoding in the MDCT field through obtaining the decorrelation signals in the MDCT field.

Description

Coding and decoding device, system and method thereof

Technical field

The present invention relates to a kind of coding and decoding device, system and method thereof, relate in particular to stereophonic signal coding and decoding device, system and the method thereof in a kind of network communications technology field.

Background technology

Stereophonic signal is to transmit or rebuild some specific sound fields, reproduce sound and the spatial character of original sound field to attentive listener, its broadcasting, film (depending on), be widely used in culture and the daily life, particularly in recent years because the development of computer technology, Digital Signal Processing, and owing to develop the needs of high-definition television sound system, home audiovisual system, stereo encoding and decoding technique is had higher requirement.

The parameter stereo coding technology is to improve a kind of technology of stereo coding efficient at low bit rate, decomposites its expressed as parameters from the stereo image of sound signal, and original signal only can be encoded as monophony and represents under traditional mode.Stereo image information is expressed as a small amount of high-quality parameter stereo information, with monophonic signal (Mono) simultaneously transmission in bit stream.Then, based on the parameter stereo information that receives, demoder just can be rebuild stereo image.Existing parameter stereo coding method can be divided into based on the stereo encoding method of fast Fourier transform (FFT) with based on the stereo encoding method of complex orthogonal mirror filter group (CQMF) wave filter, these two kinds of methods are close, and are just different when doing time frequency analysis.

In realizing process of the present invention, the inventor finds that there is following defective at least in above-mentioned prior art: existing parameter stereo coding method all is the parameter stereo codings that carry out at complex frequency domain, if for the discrete cosine transform domain that does not have the Apparently Including phase information (MDCT), G.VBR and G.729.1 for example, because can not be as FFT territory or QMF territory direct change phase place, cause the method not use.

Summary of the invention

The invention provides a kind of coding and decoding device, system and method thereof, it can be implemented in the MDCT territory and carry out stereo coding/decoding.

In one embodiment of the invention, can provide a kind of code device, be applied to the coding of stereophonic signal, it comprises:

The MDCT conversion module is used for the part stereophonic signal is carried out the conversion of MDCT territory;

Parameter acquisition module is for the stereo parameter of obtaining signal after the conversion of MDCT territory;

Quantization modules is used for described stereo parameter is quantized into the stereo parameter data;

Lower mixed module is used for and will blendes together monophonic signal under the stereophonic signal;

Coding module is used for described monophonic signal is processed into coded signal;

Composite module is used for the stereo parameter data after the described quantification and the compound rear transmission of coded signal.

In another embodiment of the present invention, can provide a kind of decoding device, be applied to the decoding of stereophonic signal, it comprises:

Separate composite module, be used for the receive data solution is combined into stereo parameter data and coded signal;

The de-quantization module is used for the stereo parameter that described stereo parameter data de-quantization is obtained;

Decoder module is used for described coded signal is decoded into monophonic signal;

The decorrelated signals generation module is for the decorrelated signals that obtains monophonic signal in the MDCT territory;

Synthesis module is used for the synthetic stereophonic signal that recovers of described stereo parameter, monophonic signal and decorrelated signals.

In another embodiment of the present invention, can provide a kind of decorrelated signals generation module for decoding device, it comprises:

Phase generator is for generation of the skew phase place;

The sine and cosine computing unit is used for calculating sine value and the cosine value at described skew phasing degree;

The Hilbert transducer is used for the MDCT domain coefficient of monophonic signal is carried out the Hibert conversion;

Multiplier be used for calculating respectively the MDCT domain coefficient of monophonic signal and the amassing of cosine value at described skew phasing degree, and the MDCT domain coefficient of monophonic signal is by long-pending with the sine value at described skew phasing degree after the Hibert conversion;

Totalizer, the long-pending MDCT domain coefficient that deducts described monophonic signal of the MDCT domain coefficient that is used for calculating described monophonic signal and the cosine value at described skew phasing degree by after the Hibert conversion with the result who amasss of the sine value at described skew phasing degree.

In another embodiment of the present invention, can provide a kind of coding/decoding system, comprise encoding apparatus and decoding apparatus, be applied to the encoding and decoding of stereophonic signal, it comprises:

Described code device comprises: the MDCT conversion module is used for the part stereophonic signal is carried out the conversion of MDCT territory; Parameter acquisition module is for the stereo parameter of obtaining signal after the conversion of MDCT territory; Quantization modules is used for described stereo parameter is quantized into the stereo parameter data; Lower mixed module is used for and will blendes together monophonic signal under all the other stereophonic signals; Coding module is used for described monophonic signal is processed into coded signal; Composite module is used for the stereo parameter data after the described quantification and the compound rear transmission of coded signal;

Described decoding device comprises: separate composite module, be used for the receive data solution is combined into stereo parameter data and coded signal; The de-quantization module is used for the stereo parameter that described stereo parameter data de-quantization is obtained; Decoder module is used for described coded signal is decoded into monophonic signal; The decorrelated signals generation module is for the decorrelated signals that obtains monophonic signal in the MDCT territory; Synthesis module is used for the synthetic stereophonic signal that recovers of described stereo parameter, monophonic signal and decorrelated signals.

In another embodiment of the present invention, can provide a kind of coding method, be applied to the coding of stereophonic signal, it comprises:

Obtain stereophonic signal to be encoded after the conversion of MDCT territory stereo parameter and carry out quantification treatment;

Blend together the monophonic signal coding under the stereophonic signal;

With stereo parameter and the compound rear transmission of coded signal after quantizing.

In another embodiment of the present invention, can provide a kind of coding/decoding method, be applied to the decoding of stereophonic signal, it comprises:

Data solution to be decoded is combined into stereo parameter and coded signal;

The above-mentioned stereo parameter of de-quantization;

Coded signal is decoded into monophonic signal;

Obtain monophonic signal at the decorrelated signals in MDCT territory;

With the synthetic stereophonic signal that recovers of stereo parameter, monophonic signal, the decorrelated signals of de-quantization.

In another embodiment of the present invention, can provide a kind of decorrelated signals generation method for coding/decoding method, it comprises:

Obtain the MDCT coefficient of described monophonic signal;

It is long-pending with the cosine value at skew phasing degree to calculate this MDCT coefficient, and this MDCT coefficient is by long-pending with the sine value at skew phasing degree after the Hibert conversion;

Calculate the cosine value at this MDCT coefficient and random offset phasing degree long-pending deduct this MDCT coefficient by after the Hibert conversion with the long-pending result of the sine value at skew phasing degree.

In another embodiment of the present invention, can provide a kind of decoding method, be applied to the encoding and decoding of stereophonic signal, it comprises:

Obtain stereophonic signal to be encoded after the conversion of MDCT territory stereo parameter and carry out quantification treatment;

Blend together the monophonic signal coding under the stereophonic signal;

With stereo parameter and the compound rear transmission of coded signal after quantizing;

Data solution to be decoded is combined into stereo parameter and coded signal;

The above-mentioned stereo parameter of de-quantization;

Coded signal is decoded into monophonic signal;

Obtain monophonic signal at the decorrelated signals in MDCT territory;

With the synthetic stereophonic signal that recovers of stereo parameter, monophonic signal, the decorrelated signals of de-quantization.

Compared to existing technologies, technical scheme in the embodiment of the invention has following advantage at least: embodiment of the invention coding and decoding device, system and method thereof are carried out stereo coding in the MDCT territory, by obtaining decorrelated signals in the MDCT territory, can solve how to obtain two-way left and right acoustic channels stereophonic signal in decoding end by one road monophonic signal, be implemented in the MDCT territory and carry out stereo coding/decoding.

Description of drawings

In order to be illustrated more clearly in the embodiment of the invention or technical scheme of the prior art, the below will do one to the accompanying drawing of required use in embodiment or the description of the Prior Art and introduce simply, apparently, accompanying drawing in the following describes only is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.

Fig. 1 is the synoptic diagram of the code device of embodiment of the invention coding/decoding system;

Fig. 2 is the synoptic diagram of the decoding device of embodiment of the invention coding/decoding system;

Fig. 3 is the synoptic diagram of decorrelated signals generation module of the decoding device of embodiment of the invention coding/decoding system;

Fig. 4 is the synoptic diagram that the decorrelated signals generation module of the decoding device of embodiment of the invention coding/decoding system generates the random offset phase place;

Fig. 5 is the synoptic diagram of embodiment of the invention coding method;

Fig. 6 is the synoptic diagram of embodiment of the invention coding/decoding method;

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the invention, the technical scheme in the embodiment of the invention is clearly and completely described, obviously, described embodiment only is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not making the every other embodiment that obtains under the creative work prerequisite.

See also Fig. 1 and Fig. 2, the coding/decoding system that the embodiment of the invention is applicable to stereophonic signal comprises code device 10 and decoding device 20.Code device 10 comprises MDCT conversion module 11, parameter acquisition module 12, quantization modules 13, lower mixed module 14 (Down Mix), coding module 15 and composite module 16.Wherein, MDCT conversion module 11, parameter acquisition module 12, quantization modules 13 connect successively, and lower mixed module 14 is connected connection with coding module, and quantization modules 13 is connected with coding module and is connected with composite module 16 respectively.The left and right sound track signals of stereophonic signal (L and R) is divided into two-way respectively, MDCT conversion module 11 carries out the conversion of MDCT territory with one tunnel left and right sound track signals, and (present embodiment is two, divide left and right acoustic channels to carry out respectively the conversion of MDCT territory), parameter acquisition module 12 is obtained respectively the stereo parameter of signal after the conversion of MDCT territory again, and quantization modules 13 transfers to composite module 16 after the stereo parameter data of obtaining being quantized again; Another road left and right sound track signals is sent into coding module 15 and is encoded obtain monophony (mono) signal after lower mixed module is mixed for 14 times after, and the stereo parameter data after coded signal transfers to composite module 16 and quantizes are combined into bit stream and transmit.

Be appreciated that stereo parameter that the parameter acquisition module 12 of present embodiment code device 10 is obtained comprises the energy Ratios (IID[b], Interchannel intensity difference) of left and right sound track signals, following formula (1):

$\mathrm{IID}\left[b\right]=10\×\log \frac{{\mathrm{\Σ}}_{k=k_b}^{k_{b+1}-1}{X}_1\left[k\right]X_1\left[k\right]}{{\mathrm{\Σ}}_{k=k_b}^{k_{b+1}-1}{X}_2\left[k\right]X_2\left[k\right]},---\left(1\right)$

And the left and right sound track signals correlativity (IC[b], Inter-channel coherence), following formula (2):

$\mathrm{IC}\left[b\right]=\frac{\left|{\mathrm{\Σ}}_{k=k_b}^{k_{b+1}-1}{X}_1\right[k\left]X_2\right[k\left]\right|}{\sqrt{\left({\mathrm{\Σ}}_{k=k_b}^{k_{b+1}-1}{X}_1\right[k\left]X_1\right[k\left]\right)\left({\mathrm{\Σ}}_{k=k_b}^{k_{b+1}-1}{X}_2\right[k\left]X_2\right[k\left]\right)}},---\left(2\right)$

X wherein ₁[k], X ₂[k] represents respectively the MDCT coefficient of left and right sound track signals, and stereo parameter is obtained take subband as the basis.

Lower mixed module 14 is with synthetic one road mono signal of another road left and right sound track signals, and synthetic can carrying out in time domain also can carry out in the MDCT territory.If synthetic in the MDCT territory, then carry out according to following formula (3):

S[k]＝w ₁X ₁[k]+w ₂X ₂[k](3)

Because in the MDCT territory or blending together mono signal (in these two territories, signal all is real number) under the time domain, so w ₁And w ₂Be real number.w ₁And w ₂Can temporal evolution, also can fix.For simplicity, present embodiment definition w ₁And w ₂Be respectively 0.5.

13 couples of IID[b of quantization modules] and IC[b] parameter quantizes, this two classes parameter both can be used scalar quantization, also can use the method for vector quantization to quantize.

Coding module 15 is monophony speech coder arbitrarily.Such as G.VBR, core encoder G.729.1 etc.As long as this scrambler just can be applicable to the present invention based on the time frequency analysis of MDCT.

The decoding device 20 of the embodiment of the invention comprises separates composite module 21, de-quantization module 22, decoder module 23, decorrelated signals generation module 24 and synthesis module 25.Wherein, de-quantization module 22 are connected with decoder module a side respectively with separate composite module 21 and be connected, opposite side is connected with synthesis module 25 respectively, decorrelated signals generation module 24 is connected with synthesis module with decoder module 23 respectively and is connected.Separate the composite bit stream that composite module 21 receives code device 10 transmission, its solution is combined into the stereo parameter data to solution composite module 21 and coded signal transfers to respectively de-quantization module 22 and decoder module 23, de-quantization module 22 obtains decoded stereo parameter (present embodiment comprises IID[b] and IC[b]) with stereo parameter data de-quantization, the mono signal that decoder module 23 is restored out after coded signal is decoded, simultaneously, the Mono signal is also sent into decorrelated signals generation module 24, obtain the decorrelated signals of mono signal in the MDCT territory, above-mentioned stereo parameter, mono signal and decorrelated signals transfer to synthesis module 25 together, the synthetic left and right acoustic channels stereophonic signal that recovers (L ' and R ').

Be appreciated that the embodiment of the invention processes the decorrelated signals obtain the mono signal through decorrelated signals generation module 24 in the MDCT territory, it has identical amplitude spectrum and different phase spectrums from original signal.

See also Fig. 3, the decorrelated signals generation module 24 of present embodiment comprises Hilbert transducer 241, phase generator 242, sine and cosine computing unit 243, multiplier 244 and totalizer 245.For generating decorrelated signals, 242 needs of phase generator produce random phase, namely get final product for each frequency component generates a skew phase place (theta) at random; Sine and cosine computing unit 243 is used for calculating sine value and the cosine value at described skew phasing degree; Hilbert transducer 241 is used for the MDCT domain coefficient of monophonic signal is carried out the Hibert conversion; Multiplier 244 be used for calculating respectively the MDCT domain coefficient of monophonic signal and the amassing of cosine value at described skew phasing degree, and the MDCT domain coefficient of monophonic signal is by long-pending with the sine value at described skew phasing degree after the Hibert conversion; Totalizer 245, the long-pending MDCT domain coefficient that deducts described monophonic signal of the MDCT domain coefficient that is used for calculating described monophonic signal and the cosine value at described skew phasing degree by after the Hibert conversion with the result who amasss of the sine value at described skew phasing degree.Be appreciated that, in order to reduce algorithm complex, above-mentioned random offset phase place can calculated in advance out be stored in the decoder module 23, when calculating decorrelated signals in the mode of round-robin queue at every turn, a random site from round-robin queue begins, and order is extracted phase place.The calculated amount of having avoided so each generation random phase to bring sees also Fig. 4.

Decorrelated signals S _d[k] can try to achieve by following formula (4):

S _d[k]=S[k] * cos (theta)-Hilbert (S[k]) * sin (theta) k=1...N (4) wherein

S[k wherein] be the MDCT coefficient of mono signal, the number of coefficient is N, can obtain relative S[k by formula (4)] the decorrelated signals S of theta phase deviation arranged _d[k].Be appreciated that MDCT coefficient that decorrelated signals that the decorrelated signals generation module 24 through present embodiment generates is original signal and the long-pending MDCT coefficient of original signal that deducts of theta cosine of an angle value are by amassing with the sine value at theta angle is after the Hibert conversion.

Equally, the decorrelated signals generation module 24 of present embodiment also can be used to revise in the MDCT territory phase place of signal, and this phase place can be obtained at code device 10, obtains after decoder module 23 decodings.Can at first calculate the FFT coefficient of signal at code device 10, then calculate two relative phases skews (IPD[b] Inter-channel phase difference) between the sound channel by following formula (5).

$\mathrm{IPD}\left[b\right]=\∠\left(\underset{k=k_b}{\overset{k_{b+1}-1}{\mathrm{\Σ}}}{X}_1\right[k\left]x_2^{*}\right[k\left]\right)---\left(5\right)$

Before utilizing formula 6 reconstruction left and right sound track signals, the phase place of calculating take formula 5 is as theta, utilize the decorrelated signals generation module 24 of present embodiment to come the phase place of signal is made amendment, that be input to decorrelated signals generation module 24 this moment can be S[k] or S _d[k] that is to say that the phase place that phase generator 242 at this moment obtains depends on stereophonic signal itself, is the foundation that is characterized as with signal.

In synthesis module 25, the MDCT coefficient S [k] of mono signal and the MDCT coefficient S of decorrelated signals _d[k] changes the MDCT coefficient Y that obtains synthetic left and right sound track signals L ' and R ' by following matrix ₁[k], Y ₂[k].Before utilizing formula 6 reconstruction left and right sound track signals, can carry out the phase place adjustment of above-mentioned dependence signal.The step that is appreciated that above-mentioned phase place adjustment also can be omitted, when being applied to high-frequency signal such as the decoder module 20 of the embodiment of the invention.

$\left[\begin{array}{c}{Y}_1\left[k\right]\\ Y_2\left[k\right]\end{array}\right]=R_B\left[\begin{array}{c}S\left[k\right]\\ S_d\left[k\right]\end{array}\right]---\left(6\right)$

R wherein _BFor $R_B\left[b\right]=\sqrt{2}A\left[b\right]V\left[b\right],$ A[b] and V[b] can obtain the R that finally obtains by formula (7) and (8) respectively _BShown in formula (9), the parameters in the formula (9) is calculated by formula (10).

$R_B\left[b\right]=\sqrt{2}P\left[b\right]A\left[b\right]V\left[b\right]---\left(7\right)$

$P\left[b\right]=\left[\begin{array}{cc}{e}^{\mathrm{jOPD}\left[b\right]}& 0\\ 0& e^{\mathrm{jOPD}\left[b\right]-\mathrm{jIPD}\left[b\right]}\end{array}\right]---\left(8\right)$

$A\left[b\right]=\left[\begin{array}{cc}\cos \left(\mathrm{\α}\right[b\left]\right)& -\sin \left(\mathrm{\α}\right[b\left]\right)\\ \sin \left(\mathrm{\α}\right[b\left]\right)& \cos \left(\mathrm{\α}\right[b\left]\right)\end{array}\right]---\left(9\right)$

$V\left[b\right]=\left[\begin{array}{cc}\cos \left(\mathrm{\γ}\right[b\left]\right)& 0\\ 0& \sin \left(\mathrm{\γ}\right[b\left]\right)\end{array}\right]---\left(10\right)$

The coding/decoding system that is appreciated that the embodiment of the invention carries out stereo coding in the MDCT territory, by having obtained decorrelated signals in the MDCT territory, can solve how to obtain two paths of signals in decoding end by one road signal, is implemented in the MDCT territory and carries out stereo coding/decoding.

See also Fig. 5, be appreciated that the decoding method that the embodiment of the invention is applicable to stereophonic signal comprises coding method and coding/decoding method, wherein coding method may further comprise the steps:

501, obtain stereophonic signal to be encoded after the conversion of MDCT territory stereo parameter and carry out quantification treatment;

502, blend together monophony (mono) Signal coding under the stereophonic signal;

503, stereo parameter and the compound rear transmission of coded signal after will quantizing.

Be appreciated that above-described embodiment method specifically comprises, is divided into two-way with stereophonic signal to be encoded; The left and right sound track signals of one road stereophonic signal is wherein carried out respectively obtaining stereo parameter after the conversion of MDCT territory, again the stereo parameter of obtaining is quantized; Under another road signal mixed obtain the mono signal after, encode again; The compound rear transmission of stereo parameter data after will quantizing again and coded signal.

See also Fig. 6, be appreciated that the coding/decoding method that the embodiment of the invention is applicable to stereophonic signal may further comprise the steps:

601, data solution to be decoded is combined into stereo parameter and coded signal;

602, the above-mentioned stereo parameter of de-quantization;

603, coded signal is decoded into monophonic signal;

604, obtain monophonic signal at the decorrelated signals in MDCT territory;

605, with the synthetic stereophonic signal that recovers of stereo parameter, monophonic signal, the decorrelated signals of de-quantization.

Be appreciated that above-described embodiment method specifically comprises, the data solution to be decoded that receives is combined into quantification stereo parameter and coded signal; Obtain decoded stereo parameter to quantizing the stereo parameter de-quantization; Monophonic signal to coded signal is decoded and is restored out simultaneously, obtains monophonic signal at the decorrelated signals in MDCT territory, and this decorrelated signals has identical amplitude spectrum and different phase spectrums from original stereo signal; The synthetic left and right acoustic channels stereophonic signal that recovers of the stereo parameter of de-quantization, monophonic signal, decorrelated signals just.

In above-described embodiment method, the decorrelated signals acquisition methods comprises: the MDCT coefficient that obtains original signal, it is long-pending with skew phase place theta cosine of an angle value to calculate this MDCT coefficient, and this MDCT coefficient is by long-pending with the sine value at theta angle after the Hibert conversion, deducts this MDCT coefficient and namely obtains decorrelated signals with the amassing of sine value at theta angle after by the Hibert conversion with the amassing of this MDCT coefficient and random offset phase place theta cosine of an angle value.Above-mentioned skew phasing degree can be to generate at random, perhaps, generates (because people's ear is different in the resolution of different frequency section, can so that phase place reduces with the rising of frequency) according to the characteristic of signal, and the phase place of signal is made amendment obtains again.

Be appreciated that, the decoding method of the embodiment of the invention carries out stereo coding in the MDCT territory, by having obtained decorrelated signals in the MDCT territory, can solve how to obtain two-way left and right acoustic channels stereophonic signal in decoding end by one road monophonic signal, be implemented in the MDCT territory and carry out stereo coding/decoding.Although what the embodiment of the invention was described is the decoding method of stereophonic signal, embodiment of the invention decoding method and decorrelated signals generation method can be applied in the multi-channel encoder scheme easily.

Through the above description of the embodiments, those skilled in the art can be well understood to the present invention and can realize by the mode that software adds essential hardware platform, can certainly all implement by hardware, but the former is better embodiment in a lot of situation.Based on such understanding, technical scheme of the present invention is to can embodying with the form of software product in whole or in part that background technology contributes, this computer software product can be stored in the storage medium, such as ROM/RAM, magnetic disc, CD etc., comprise that some instructions are with so that a computer equipment (can be personal computer, server, the perhaps network equipment etc.) carry out the described method of some part of each embodiment of the present invention or embodiment.

Although above-described only is embodiment, and do not mean that protection scope of the present invention only limits to described embodiment.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not making under the creative work prerequisite by revising, be equal to, substituting the every other embodiment that obtains.

Claims (13)

1. a decoding device is applied to the decoding of stereophonic signal, it is characterized in that comprising:

Separate composite module, be used for stereo parameter data that the received code end is sent and the coded signal data solution after compound and be combined into stereo parameter data and coded signal; The stereo parameter data that described coding side sends are that described coding side is processed the stereo parameter data that obtain with stereophonic signal to be encoded through discrete cosine transform domain MDCT territory transform and quantization, and the coded signal that described coding side sends is described coding side with the coded signal that blendes together the monophonic signal aftertreatment under the stereophonic signal and obtain; The de-quantization module is used for the stereo parameter that described stereo parameter data de-quantization is obtained;

Decoder module is used for described coded signal is decoded into monophonic signal;

The decorrelated signals generation module is for the decorrelated signals that obtains monophonic signal in the MDCT territory; Described decorrelated signals be the long-pending MDCT domain coefficient that deducts monophonic signal of the cosine value at the MDCT domain coefficient of monophonic signal and a skew phasing degree by after the Hibert conversion with the long-pending result of the sine value at described skew phasing degree;

Synthesis module is used for the synthetic stereophonic signal that recovers of described stereo parameter, monophonic signal and decorrelated signals.

2. device as claimed in claim 1, it is characterized in that: described decorrelated signals has identical amplitude spectrum and different phase spectrums from monophonic signal.

3. decorrelated signals generation module that is used for decoding device as claimed in claim 1 is characterized in that comprising:

Phase generator is for generation of the skew phase place;

The sine and cosine computing unit is used for calculating sine value and the cosine value at described skew phasing degree;

The Hilbert transducer is used for the discrete cosine transform domain MDCT domain coefficient of monophonic signal is carried out the Hibert conversion;

Multiplier be used for calculating respectively the MDCT domain coefficient of monophonic signal and the amassing of cosine value at described skew phasing degree, and the MDCT domain coefficient of monophonic signal is by long-pending with the sine value at described skew phasing degree after the Hibert conversion;

Totalizer, the long-pending MDCT domain coefficient that deducts described monophonic signal of the MDCT domain coefficient that is used for calculating described monophonic signal and the cosine value at described skew phasing degree by after the Hibert conversion with the result who amasss of the sine value at described skew phasing degree.

4. a coding/decoding system comprises encoding apparatus and decoding apparatus, is applied to the encoding and decoding of stereophonic signal, it is characterized in that comprising:

Described code device comprises: discrete cosine transform domain MDCT conversion module is used for the part stereophonic signal is carried out the conversion of MDCT territory; Parameter acquisition module is for the stereo parameter of obtaining signal after the conversion of MDCT territory; Quantization modules is used for described stereo parameter is quantized into the stereo parameter data; Lower mixed module is used for and will blendes together monophonic signal under all the other stereophonic signals; Coding module is used for described monophonic signal is processed into coded signal; Composite module is used for the stereo parameter data after the described quantification and the compound rear transmission of coded signal;

Described decoding device comprises: separate composite module, be used for the receive data solution is combined into stereo parameter data and coded signal; The de-quantization module is used for the stereo parameter that described stereo parameter data de-quantization is obtained; Decoder module is used for described coded signal is decoded into monophonic signal; The decorrelated signals generation module is for the decorrelated signals that obtains monophonic signal in the MDCT territory; Described decorrelated signals be the long-pending MDCT domain coefficient that deducts monophonic signal of the cosine value at the MDCT domain coefficient of monophonic signal and a skew phasing degree by after the Hibert conversion with the long-pending result of the sine value at described skew phasing degree; Synthesis module is used for the synthetic stereophonic signal that recovers of described stereo parameter, monophonic signal and decorrelated signals.

5. system as claimed in claim 4, it is characterized in that: described decorrelated signals has identical amplitude spectrum and different phase spectrums from monophonic signal.

6. a coding/decoding method is applied to the decoding of stereophonic signal, it is characterized in that comprising:

Data solution to be decoded is combined into stereo parameter and coded signal; Described data to be decoded are the stereo parameter data that send of coding side and coded signal data after compound, the stereo parameter data that described coding side sends are that described coding side is processed the stereo parameter data that obtain with stereophonic signal to be encoded through discrete cosine transform domain MDCT territory transform and quantization, and the coded signal that described coding side sends is described coding side with the coded signal that blendes together the monophonic signal aftertreatment under the stereophonic signal and obtain;

The above-mentioned stereo parameter of de-quantization;

Coded signal is decoded into monophonic signal;

Obtain monophonic signal at the decorrelated signals in MDCT territory; Described decorrelated signals be the long-pending MDCT domain coefficient that deducts monophonic signal of the cosine value at the MDCT domain coefficient of monophonic signal and a skew phasing degree by after the Hibert conversion with the long-pending result of the sine value at described skew phasing degree;

With the synthetic stereophonic signal that recovers of stereo parameter, monophonic signal, the decorrelated signals of de-quantization.

7. method as claimed in claim 6, it is characterized in that: described decorrelated signals has identical amplitude spectrum and different phase spectrums from monophonic signal.

8. decorrelated signals generation method that is used for coding/decoding method as claimed in claim 6 is characterized in that comprising:

Obtain the discrete cosine transform domain MDCT coefficient of described monophonic signal;

It is long-pending with the cosine value at skew phasing degree to calculate this MDCT coefficient, and this MDCT coefficient is by long-pending with the sine value at skew phasing degree after the Hibert conversion;

Calculate the cosine value at this MDCT coefficient and random offset phasing degree long-pending deduct this MDCT coefficient by after the Hibert conversion with the long-pending result of the sine value at skew phasing degree.

9. method as claimed in claim 8, it is characterized in that: described skew phasing degree is to generate at random, perhaps, generates according to the characteristic of signal, the phase place of signal is made amendment obtains again.

10. a decoding method is applied to the encoding and decoding of stereophonic signal, it is characterized in that comprising:

Coding side obtain stereophonic signal to be encoded after discrete cosine transform domain MDCT territory conversion stereo parameter and carry out quantification treatment; Blend together the monophonic signal coding under the stereophonic signal; With stereo parameter and the compound rear transmission of coded signal after quantizing;

Decoding end is combined into stereo parameter and coded signal with data solution to be decoded; The above-mentioned stereo parameter of de-quantization; Coded signal is decoded into monophonic signal; Obtain monophonic signal at the decorrelated signals in MDCT territory; Described decorrelated signals be the long-pending MDCT domain coefficient that deducts monophonic signal of the cosine value at the MDCT domain coefficient of monophonic signal and a skew phasing degree by after the Hibert conversion with the long-pending result of the sine value at described skew phasing degree; With the synthetic stereophonic signal that recovers of stereo parameter, monophonic signal, the decorrelated signals of de-quantization.

11. method as claimed in claim 10 is characterized in that: described decorrelated signals has identical amplitude spectrum and different phase spectrums from monophonic signal.

12. method as claimed in claim 11 is characterized in that: obtaining of described decorrelated signals comprises:

Obtain the MDCT coefficient of described monophonic signal;

It is long-pending with the cosine value at skew phasing degree to calculate this MDCT coefficient, and this MDCT coefficient is by long-pending with the sine value at skew phasing degree after the Hibert conversion;

Calculate the cosine value at this MDCT coefficient and random offset phasing degree long-pending deduct this MDCT coefficient by after the Hibert conversion with the long-pending result of the sine value at skew phasing degree.

13. method as claimed in claim 12 is characterized in that: described skew phasing degree is to generate at random, and perhaps, according to the characteristic generation of signal, the phase place of signal is made amendment obtains again.

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