CN101604983A - Coding and decoding device, system and method thereof - Google Patents

Abstract

The embodiment of the invention provides a kind of coding and decoding device, system and method thereof that is applied to stereophonic signal, and 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; Stereo parameter after quantizing and the compound back of code signal are sent; Data to be decoded are separated be combined into stereo parameter and code signal; The above-mentioned stereo parameter of de-quantization; Code signal is decoded into monophonic signal; Obtain the decorrelated signals of monophonic signal in the MDCT territory; With the synthetic stereophonic signal that recovers of stereo parameter, monophonic signal, the decorrelated signals of de-quantization.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 by one road monophonic signal, be implemented in the MDCT territory and carry out stereo coding/decoding in decoding end.

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 the sound and the spatial character of original sound field to attentive listener, it is widely used in broadcasting, film (looking), culture and daily life, particularly in recent years because the development of computer technology, Digital Signal Processing, and, stereo encoding and decoding technique is had higher requirement owing to develop the needs of high definition TV sound system, home audiovisual system.

The parameter stereo coding technology is to improve a kind of technology of stereo coding efficient at low bit rate, decomposite its parameter and represent from the stereo image of audio signal, and primary signal only can be encoded as monophony and represents under traditional mode.Stereo image information is expressed as a spot of high-quality parameter stereo information, with monophonic signal (Mono) transmission simultaneously in bit stream.Then, based on the parameter stereo information that receives, decoder 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) filter, these two kinds of methods are close, just difference 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 there not being the explicit discrete cosine transform domain (MDCT) that comprises phase information, G.VBR and G.729.1 for example, because can not be as FFT territory or QMF territory direct change phase place, cause this 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 used to obtain the stereo parameter of signal after the conversion of MDCT territory;

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

Mixed module is used for and will blendes together monophonic signal under the stereophonic signal down;

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

Composite module is used for stereo parameter data after the described quantification and code signal compound back transmission.

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 reception data are separated and be combined into stereo parameter data and code 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 code signal is decoded into monophonic signal;

The decorrelated signals generation module is used for obtaining in the MDCT territory decorrelated signals of monophonic signal;

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 that is used for decoding device, it comprises:

Phase generator is used for producing the skew phase place;

The sine and cosine computing unit is used to calculate the sine value and the cosine value at described skew phase angle;

The Hilbert converter 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 phase angle, and the MDCT domain coefficient of monophonic signal is by long-pending with the sine value at described skew phase angle after the Hibert conversion;

Adder, be used to calculate the long-pending MDCT domain coefficient that deducts described monophonic signal of the cosine value at the MDCT domain coefficient of described monophonic signal and described skew phase angle by after the Hibert conversion with the long-pending result of the sine value at described skew phase angle.

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 used to obtain the stereo parameter of signal after the conversion of MDCT territory; Quantization modules is used for described stereo parameter is quantized into the stereo parameter data; Mixed module is used for and will blendes together monophonic signal under all the other stereophonic signals down; Coding module is used for described monophonic signal is processed into code signal; Composite module is used for stereo parameter data after the described quantification and code signal compound back transmission;

Described decoding device comprises: separate composite module, be used for the reception data are separated and be combined into stereo parameter data and code 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 code signal is decoded into monophonic signal; The decorrelated signals generation module is used for obtaining in the MDCT territory decorrelated signals of monophonic signal; 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;

Stereo parameter after quantizing and the compound back of code signal are sent.

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 to be decoded are separated be combined into stereo parameter and code signal;

The above-mentioned stereo parameter of de-quantization;

Code signal is decoded into monophonic signal;

Obtain the decorrelated signals of monophonic signal in the 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 that is used for coding/decoding method, it comprises:

Obtain the MDCT coefficient of described monophonic signal;

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

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

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;

Stereo parameter after quantizing and the compound back of code signal are sent;

Data to be decoded are separated be combined into stereo parameter and code signal;

The above-mentioned stereo parameter of de-quantization;

Code signal is decoded into monophonic signal;

Obtain the decorrelated signals of monophonic signal in the 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 by one road monophonic signal, be implemented in the MDCT territory and carry out stereo coding/decoding in decoding end.

Description of drawings

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

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

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

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

Fig. 4 is the schematic 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 schematic diagram of embodiment of the invention coding method;

Fig. 6 is the schematic 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 is obtained under the creative work prerequisite.

See also Fig. 1 and Fig. 2, the embodiment of the invention is applicable to that the coding/decoding system of 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, following 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 following mixed module 14 is connected with coding module 15, and quantization modules 13 is connected with composite module 16 respectively with coding module 15.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 the conversion of MDCT territory respectively), parameter acquisition module 12 is obtained the stereo parameter of signal after the conversion of MDCT territory more respectively, 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 to encode obtain monophony (mono) signal after mixed module is mixed for 14 times down after, and the stereo parameter data after code signal transfers to composite module 16 and quantizes are combined into bit stream and transmit.

Be appreciated that energy that stereo parameter that the parameter acquisition module 12 of present embodiment code device 10 is obtained comprises left and right sound track signals than (IID[b], Interchannel intensity difference), 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 correlation (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 the MDCT coefficient of left and right sound track signals respectively, and stereo parameter is obtained based on subband.

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

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 a real number) under the time domain, so w ₁And w ₂Be real number.w ₁And w ₂Can change in time, 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.As G.VBR, core encoder G.729.1 etc.As long as this encoder 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 and decoder module 23 1 sides 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 25 with decoder module 23 respectively.Separate the composite bit stream that composite module 21 receives code device 10 transmission, separating composite module 21 separates it and is combined into the stereo parameter data and code signal transfers to de-quantization module 22 and decoder module 23 respectively, 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 code 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 handles 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 with primary signal.

See also Fig. 3, the decorrelated signals generation module 24 of present embodiment comprises Hilbert converter 241, phase generator 242, sine and cosine computing unit 243, multiplier 244 and adder 245.For generating decorrelated signals, 242 needs of phase generator produce random phase, just get final product for each frequency component generates a skew phase place (theta) at random; Sine and cosine computing unit 243 is used to calculate the sine value and the cosine value at described skew phase angle; Hilbert converter 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 phase angle, and the MDCT domain coefficient of monophonic signal is by long-pending with the sine value at described skew phase angle after the Hibert conversion; Adder 245, be used to calculate the long-pending MDCT domain coefficient that deducts described monophonic signal of the cosine value at the MDCT domain coefficient of described monophonic signal and described skew phase angle by after the Hibert conversion with the long-pending result of the sine value at described skew phase angle.Be appreciated that, in order to reduce algorithm complex, above-mentioned random offset phase place can calculated in advance be come out to 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 amount of calculation of having avoided each generation random phase to bring like this 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 primary signal and the long-pending MDCT coefficient of primary 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.At the code device 10 FFT coefficient of signal calculated at first, calculate two relative phases skews (IPD[b] Inter-channel phase difference) between the sound channel by following formula (5) then.

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

Before utilizing formula 6 reconstruction left and right sound track signals, the phase place of calculating with formula 5 is 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 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 _BAs shown in Equation (9), each parameter 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 embodiment of the invention is applicable to that the decoding method of 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 encoding under the stereophonic signal;

503, the compound back of stereo parameter after will quantizing and code signal sends.

Be appreciated that the foregoing description 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; Another road signal is encoded after mixing down and obtaining the mono signal again; The compound back transmission of stereo parameter data after will quantizing again and code signal.

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

601, data to be decoded are separated be combined into stereo parameter and code signal;

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

603, code signal is decoded into monophonic signal;

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

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

Be appreciated that the foregoing description method specifically comprises, the data to be decoded that receive separated be combined into quantification stereo parameter and code signal; Obtain decoded stereo parameter to quantizing the stereo parameter de-quantization; Monophonic signal to code signal is decoded and is restored out simultaneously, obtains the decorrelated signals of monophonic signal in the MDCT territory, and this decorrelated signals has identical amplitude spectrum and different phase spectrums with 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 the foregoing description method, the decorrelated signals acquisition methods comprises: the MDCT coefficient that obtains primary 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 promptly 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 phase angle can be to generate at random, perhaps, generates (because people's ear is in the resolution difference 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 by one road monophonic signal in decoding end, be implemented in the MDCT territory and carry out stereo coding/decoding.Though 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, but the former is better execution mode under a lot of situation by hardware.Based on such understanding, all or part of can the embodying that technical scheme of the present invention contributes to background technology with the form of software product, this computer software product can be stored in the storage medium, as ROM/RAM, magnetic disc, CD etc., comprise that some instructions are with so that a computer equipment (can be a 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.

Though 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 is obtained.

Claims (20)

1, a kind of code device is applied to the coding of stereophonic signal, it is characterized in that comprising:

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

Parameter acquisition module is used to obtain the stereo parameter of signal after the conversion of MDCT territory;

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

Mixed module is used for and will blendes together monophonic signal under the stereophonic signal down;

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

Composite module is used for stereo parameter data after the described quantification and code signal compound back transmission.

2, device as claimed in claim 1 is characterized in that: the described MDCT conversion module left and right sound track signals of stereophonic signal respectively carries out the conversion of MDCT territory.

3, device as claimed in claim 1 is characterized in that: described stereo parameter comprises the energy ratio and the left and right sound track signals correlation of left and right sound track signals.

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

Separate composite module, be used for the reception data are separated and be combined into stereo parameter data and code 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 code signal is decoded into monophonic signal;

The decorrelated signals generation module is used for obtaining in the MDCT territory decorrelated signals of monophonic signal;

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

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

6, device as claimed in claim 5 is characterized in that: described decorrelated signals is that the MDCT domain coefficient of monophonic signal and the long-pending MDCT domain coefficient that deducts monophonic signal of cosine value at a skew phase angle pass through to amass with the sine value at described skew phase angle is after the Hibert conversion.

7, a kind of decorrelated signals generation module that is used for decoding device as claimed in claim 4 is characterized in that comprising:

Phase generator is used for producing the skew phase place;

The sine and cosine computing unit is used to calculate the sine value and the cosine value at described skew phase angle;

The Hilbert converter 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 phase angle, and the MDCT domain coefficient of monophonic signal is by long-pending with the sine value at described skew phase angle after the Hibert conversion;

Adder, be used to calculate the long-pending MDCT domain coefficient that deducts described monophonic signal of the cosine value at the MDCT domain coefficient of described monophonic signal and described skew phase angle by after the Hibert conversion with the long-pending result of the sine value at described skew phase angle.

8, a kind of 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: the MDCT conversion module is used for the part stereophonic signal is carried out the conversion of MDCT territory; Parameter acquisition module is used to obtain the stereo parameter of signal after the conversion of MDCT territory; Quantization modules is used for described stereo parameter is quantized into the stereo parameter data; Mixed module is used for and will blendes together monophonic signal under all the other stereophonic signals down; Coding module is used for described monophonic signal is processed into code signal; Composite module is used for stereo parameter data after the described quantification and code signal compound back transmission;

Described decoding device comprises: separate composite module, be used for the reception data are separated and be combined into stereo parameter data and code 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 code signal is decoded into monophonic signal; The decorrelated signals generation module is used for obtaining in the MDCT territory decorrelated signals of monophonic signal; Synthesis module is used for the synthetic stereophonic signal that recovers of described stereo parameter, monophonic signal and decorrelated signals.

System as claimed in claim 8 is characterized in that: described decorrelated signals has identical amplitude spectrum and different phase spectrums with monophonic signal.

9, system as claimed in claim 8 is characterized in that: described decorrelated signals is that the MDCT domain coefficient of monophonic signal and the long-pending MDCT domain coefficient that deducts monophonic signal of cosine value at a skew phase angle pass through to amass with the sine value at described skew phase angle is after the Hibert conversion.

10, a kind of coding method is applied to the coding of stereophonic signal, it is characterized in that comprising:

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;

Stereo parameter after quantizing and the compound back of code signal are sent.

11, method as claimed in claim 10 is characterized in that: described method comprises stereophonic signal to be encoded is divided into two-way; The left and right sound track signals of one road stereophonic signal is wherein carried out respectively extracting stereo parameter after the conversion of MDCT territory, again the stereo parameter of extracting is quantized; Another road signal is encoded after mixing down and obtaining monophonic signal again; The compound back transmission of stereo parameter data after will quantizing again and code signal.

12, method as claimed in claim 11 is characterized in that: described stereo parameter comprises the energy ratio and the left and right sound track signals correlation of left and right sound track signals.

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

Data to be decoded are separated be combined into stereo parameter and code signal;

The above-mentioned stereo parameter of de-quantization;

Code signal is decoded into monophonic signal;

Obtain the decorrelated signals of monophonic signal in the MDCT territory;

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

14, method as claimed in claim 13 is characterized in that: described decorrelated signals has identical amplitude spectrum and different phase spectrums with monophonic signal.

15, a kind of decorrelated signals generation method that is used for coding/decoding method as claimed in claim 14 is characterized in that comprising:

Obtain the MDCT coefficient of described monophonic signal;

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

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

16, method as claimed in claim 15 is characterized in that: described skew phase angle is to generate at random, and perhaps, according to the characteristic generation of signal, the phase place of signal is made amendment obtains again.

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

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;

Stereo parameter after quantizing and the compound back of code signal are sent;

Data to be decoded are separated be combined into stereo parameter and code signal;

The above-mentioned stereo parameter of de-quantization;

Code signal is decoded into monophonic signal;

Obtain the decorrelated signals of monophonic signal in the MDCT territory;

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

18, method as claimed in claim 17 is characterized in that: described decorrelated signals has identical amplitude spectrum and different phase spectrums with monophonic signal.

19, method as claimed in claim 18 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 phase angle to calculate this MDCT coefficient, and this MDCT coefficient is by long-pending with the sine value at skew phase angle after the Hibert conversion;

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

20, method as claimed in claim 19 is characterized in that: described skew phase angle 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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