EP0750811A1 - Process for coding a plurality of audio signals - Google Patents

Process for coding a plurality of audio signals

Info

Publication number
EP0750811A1
EP0750811A1 EP19950907637 EP95907637A EP0750811A1 EP 0750811 A1 EP0750811 A1 EP 0750811A1 EP 19950907637 EP19950907637 EP 19950907637 EP 95907637 A EP95907637 A EP 95907637A EP 0750811 A1 EP0750811 A1 EP 0750811A1
Authority
EP
Grant status
Application
Patent type
Prior art keywords
signals
left
channel
decoded
right
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP19950907637
Other languages
German (de)
French (fr)
Other versions
EP0750811B1 (en )
Inventor
Karlheinz Brandenburg
Ernst Eberlein
Bernhard Grill
Jürgen HERRE
Dieter Seitzer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung
Original Assignee
Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

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Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04HBROADCAST COMMUNICATION
    • H04H20/00Arrangements for broadcast or for distribution combined with broadcast
    • H04H20/86Arrangements characterised by the broadcast information itself
    • H04H20/88Stereophonic broadcast systems
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04SSTEREOPHONIC SYSTEMS 
    • H04S3/00Systems employing more than two channels, e.g. quadraphonic
    • H04S3/02Systems employing more than two channels, e.g. quadraphonic of the matrix type, i.e. in which input signals are combined algebraically, e.g. after having been phase shifted with respect to each other

Abstract

In a process for coding a plurality of audio signals, the left and right-hand basic channels and the central channel are formed into a jointly coded signal by joint stereo coding which is decoded to provide simulated decoded signals. The simulated decoded signals and two surround channels are formed by matrixing by means of a compatibility matrix into compatible signals which are suitable for decoding using existing decoders. To prevent audible interference on account of the high energy contents of the compatible signals which would occur if joint stereo coding and decoding were first performed before matrixing, the compatible signals or the simulated decoded signals dynamically weighted by means of a dynamic correction factor in such a way that the energy of the compatible signals approaches that of signals which would be obtained by the direct matrixing of the two basic channels and the central and surround channels.

Description

A method of encoding a plurality of audio signals

description

The present invention relates to a method for Codie¬ ren multiple audio signals, in which two signals whereupon the jointly coded signal is decoded to provide simulated decoded signals are combined by means of joint stereo coding at a mutually codier¬ th signal at least, which, together with further Signa ¬ len are combined to create compatible with existing decoders signals in a compatibility matrix by matrixing, according to the preamble of patent claim 1.

More particularly, the present invention is concerned with a multi-channel coding technique for audio signals which can be used in the Co¬ dierungsstandard MPEG-2.

The future MPEG2 audio standard provides not per se new coding algorithm, but rather defined Erwei¬ Chippings of coding algorithms in accordance with the standards MPEG-1 Layer I, II and III. Although MPEG-1 decoder will not be able to decode an MPEG-2 bitstream, allows the extension to a multi-channel system with up to 5 full-range audio channels with an additional Niederfre¬ quenzkanal and up to 7 multilingual channels, a so-called backward compatibility for decoder of the standard MPEG -1. In an MPEG-2 encoding for multiple audio channels, a center channel, a left and a right base channel and a left and a right of so-called "Surround" channel are typically., Coded, wherein optionally a Niederfre¬ quenzverbesserungskanal low for the independent transmission and reproduction of information is provided.

In the MPEG-2 standard value is placed on a so-called "rück¬ Windwärts compatible" transfer, that is, the coding is to be carried out so that the coded signal with existing two-channel decoders of the standards MPEG-l can be decoded. To this end, the left and right base channel L, R to be replaced of the MPEG-1 standard dimensional matrixed by Sig¬ Lc, Rc, which are generated by a compatibility matrix. The left compatible signal Lc is obtained from the left base channel, the center channel and the left surround channel by these signals multiplied by different matrix coefficients and then added to wer¬. The bit stream thus generated is decodable by an MPEG-1 decoder, however, the information center and surround information is not included separately in the MPEG-1 decoding cash compatible signals Lc, Rc.

The recovered by matrixing two-channel signal contains all the relevant signal components to allow a backward compatible decoding. Therefore, it is len sufficient in most precipitation polymerization to transfer in addition to these compatible signals three more channels within the Mehrkanalerweiterungsda- tenstroms. The missing up to two channels in the decoder by inverse matrixing or a so-called dematrixing reconstructed.

To use the Mehrkanalirrelevanz common Ste¬ be used reocodierungstechniken, such as based on the "intensity stereo Coding approximately technology" joint stereo coding. There are all together encoded signals replaced with scaled versions of a single transmitted signal genes. This is in such a manner ge tan that belongs relevant signal properties, namely, for example, the energy or the time envelopes of the signals are largely retained.

In the generation of backward compatible signals and simultaneous use of Mehrkanalirrelevanz by Verwen¬-making joint stereo coding techniques, however, the following problems:

it first creates the compatible signals Lc, Rc by matrixing and then it applies the "intensity stereo" coding or IS-coding on the remaining channels, these signals no longer match the "compatible" signals. Consequently, a dematrixing in the decoder leads to entirely different reconstructed channel signals that are audibly distorted compared to the original signals.

This problem can meet you by first applying the IS coding and then produced by matrixing the signals there are suitable patible. This forces the consistency of all the signals involved and therefore causes correct dematrizierte channels.

The above-mentioned known encoding method in which the IS-coding is applied first and then the compatible signals are produced by matrixing, is described below with reference to FIGS. 4a to 4c erläu¬ tert which the structure and operation of a known encoder and a state known decoder.

As shown in Fig. 4a is seen, the encoder has channels five Eingangs¬, namely a left and a right base channel L, R, a center channel C, and a left and a right surround channel Ls, Rs. The left and right base channel L, R and the center channel C are subjected in a first block L of a joint stereo coding, which results in a common co¬ diertes signal y. This signal, after quantization in a quantization block 2a tion block 3 zuge¬ leads which performs a packing the bit stream, so the modern standard, arrangement of the respective signals and Infor¬ mation within the bitstream carries.

The jointly encoded signal y is also supplied to a fourth block 4, which performs a joint stereo decoding of this signal to the creation of simulated decoded signals L ', R', C for the left and right base channel and the center channel. These simulated decoded signals L ', R', C one hand, and the left and right surround channel Ls, Rs are fed into a compatibility matrix 5, which testifies to the left and right compatible signal Lc ', Rc' er¬. These signals are after their quantization in the blocks 2b, 2c likewise the third block 3 is supplied to the packing of the bit stream.

In FIG. 4b, the joint stereo decoder is shown, which is part of the decoder shown in Fig. 4c is. The latter decoder comprises a block 6 for unpacking the bitstream, wherein a plurality of blocks 7a, 7b, 7c nachge¬ are switched on, the function of which is inverse to the function of the blocks 2a to 2c and which on the output side, the common encoded signal y, the left compatible signal Lc 'and the right compatible signal Rc' produce. The common codier¬ th signal y is subjected to joint stereo decoding inside the block 8 to generate the decoded signals L ', R' for the left and right base channel and the decoded signal C for the center signal. The letztge¬ named signals are supplied to the two compatible signals Lc ', Rc' to an inverse compatibility matrix 9 through which retrieved the missing channels, namely, the left and right surround channel Ls ', Rs'.

However, the invention is based on the finding that die¬ se procedure in the first IS coding is applied and then by matrixing the compatible signals are generated, although the consistency of all signals involved forces and thus causes correct dematrizierte channels, but to a changing consistency of the signals involved in the iS-coding results, making it were under Um¬ comes to audible interference of compatible channels Lc, Rc.

The invention is based on the finding that the ur¬ sprünglichen signals seek be¬ be uncorrelated generally can be, so that compatible signal add up their energies in a "real". however, one treads the last described way, in which first the IS-coding is performed and then by matrixing the compatible signals Lc, Rc are produced, the signals add amplitudes the Ampli¬ due to the complete coherence, so that as a rule, a signal is generated with a considerably higher energy.

Starting from this prior art, therefore, the vorliegen¬ the invention, the object of developing a method for encoding multiple audio signals of the aforementioned type that, despite application of common Stereocodie¬ mitigation techniques to at least a part of the to be encoded audio signals the compatible generated by matrixing bring signals no audible noise with it.

This object is achieved by a method according to claim. 1

The invention provides a method of encoding a plurality of audio signals in which

at least two signals by common encoding stereoisomers are summarized to a jointly coded signal zu¬,

the jointly coded signal is decoded to provide decoded signals simu¬ profiled, the simulated decoded signal and at least a further signal for providing compatible with existing decoders signals in a Kompatibi¬ quality matrix by matrixing wer¬ summarized the,

characterized by the step:

dynamic weights either the compatible signals or the simulated decoded signals by means of at least one dynamic Korrektur¬ factor so as to approximate the compatible signals with respect to their associated relevant signal properties to the signals which would arise in direct matrixing these at least two signals and the other signal by means of this compatibility matrix.

A dynamic rescaling or modification of the approximately Matrizie- / Dematrizierungs operation is thus carried out such that the compatible signals or the simulated decoded signals by means of at least one dynamic Korrekturfak¬ tors are weighted dynamically, so that the compatible Sig¬ dimensional with respect to their associated relevant signal properties, namely preferably their energies or its time envelope, to the corresponding signal characteristics näm¬ Lich again preferably of the energies or the time-Hüll¬ curves of those signals are approximated, which would arise at a direct matrixing (without joint stereo coding) of signals by means of Kompatiblitätsmatrix ,

Further developments and specifications of the inventive method are defined in the dependent claims.

Preferred embodiments of encoders and decoders for carrying out an exemplary method for decoding and illustrated Co¬ decoding according to the present invention in more detail with reference to the accompanying drawings. In the drawings: Fig la an encoder according to a first exemplified embodiment;.

Fig. Lb shows a block diagram of a circuit for recovering a dynamic correction factor;

Fig lc shows a first embodiment of a decoder.

FIG. 2a shows a second embodiment of an encoder;

FIG. 2b shows a block diagram of a second exemplary embodiment of a circuit for obtaining two dyna¬ mixer correction factors;

Fig. 2c, a second embodiment of a decoder;

FIG. 3a shows a third embodiment of an encoder;

FIG. 3b is a block diagram of a third exemplary embodiment of a circuit for obtaining two game dyna¬ mixer correction factors;

FIG. 3c shows a third embodiment of a decoder;

FIG. 4a is a block diagram of a known encoder;

FIG. 4b is a diagram illustrating the function of a joint stereo decoder; and

Fig. 4c is a block diagram of a known decoder.

The below with reference to Fig. La explained first embodiment of an encoder according to the invention for performing the coding method according to the invention complies with the exception of the differences described below with the method described with reference to Fig. 4a Ausfüh¬ approximately example of the known encoder match. Übereinstim¬ Mende or corresponding components or blocks with matching reference numerals.

. As is illustrated in Figure lb, the encoder according to the invention comprises a circuit 10 for calculating a single dynamic correction factor m, which following Eingangs¬ signals are supplied: the left and right base channel L, R and the center channel C and through joint stereo co- consolidation within the block 1 and by subsequent joint stereo decoding inside the block 4 produced simulated decoded right and left basic channels L, R, as well as the simulated decoded central channel C. In die¬ sem embodiment of the invention the adjustment of the associated relevant signal characteristics with respect to the energies of the opposing signals L, R, C and L, R, C is to be achieved. It should achieve energy conservation in comparison to the "right" compliant signals, the compatible signals. For this purpose, the circuit 10 calculates the single dynamic correction factor m according to the relationship folgen¬:

With this joint correction factor of each of the profiled simu¬ decoded signals L, R, C, is weighted at the output of block 4 (by means of a multiplier not shown) before the so dynamically scaled signals L, R, C, the compatibility matrix 5 are supplied. The Kompa¬ tibilitätsmatrix calculates the compatible signals Lc ', Rc' according to the following equations: (2) Lc '= a - L' + b - c + C - Ls';

Rc '= a - R' + b - c + C - Rs'.

The dynamic correction factor m is transmitted as side information within the packed block 3 of the signal to the coder De¬ shown in Fig. Lc.

Besides those already explained with reference to Fig. 4c functions of the block 6 provides for unpacking the bitstream as side information to the transferred correction factor m.

The decoded signals L ', R', C for the left and right channel and the center channel decoding of the jointly coded signal Y generated by the block 8 for the implementation of joint stereo be (by way of non ge displayed multiplier) with this dynamic Korrektur¬ factor multiplied before the thus obtained weighted signals together with the left and right compatible Sig¬ nal Lc ', Rc' of the inverse compatibility matrix 9 are supplied, which due to the signals applied thereto the lin¬ ken and right surround channel Ls ', Rs' is calculated according to the equations of the inverse compatibility matrix:

(3) Ls '(LC aL' - bC) / c

Rs '= (Rc'- aR' - bC) / c

In the above equation a and b and c are coefficients of the inverse compatibility matrix call.

In the foregoing first Ausführugsbeispiel only a single dynamic correction factor is used by which it is only possible to achieve a degree of approximation of the short-term energy profiles in the compatible signals to den¬ jenigen energy state that these signals would ideally have, which is that these signals would be directly matrixed without previous joint coding and Decodie¬ tion by the compatibility matrix. Since in real systems, the block time of the channels in the range of 10 ms, which value depends on the sampling frequency and the coding system, this solution may be too coarse under psycho-acoustic point of view. The solutions described below allow a further optimization to achieve the energy conservation in the compatible signals Lc ', RC.

wer¬ In the example shown in FIGS. 2a and 2c Ausführungs¬ second example of the encoder or decoder according to the invention the sets einge¬ in a corresponding manner except for the differences described below, the structures and functions described with reference to FIGS. 4 and 1 so that matching or similar Schal¬ are processing blocks with matching reference numerals.

The encoder according to Fig. 2a mr operates with a circuit 11 for calculating two dynamic correction factors ml, due to the left and right base channel L, R, of the Mit¬ tenkanals C, the left and right surround channels Ls, Rs and on the basis of the simulated decoded signals L ', R', C for the left channel, the right channel and the Mitten¬ channel, wherein the left and right correction factor ml, mr satisfy the following equations:

(4) | aL + bC + c-Ls |2 = | ml (aL '+ bC) + c-Ls |2

| AR + bC + c-R | mr (aR '+ bC) + c-R | 2 = |2

The simulated decoded left channel L 'and the simulated decoded central channel are plied (by means not gezeig¬ ter multiplier) with the left correction factor ml multi¬, while the other part of the simulated decoded central channel C and the simulated decoded right channel R' (by means of not gezeiger multiplier) are multiplied by the right Kor¬ rekturfaktor mr before the weighted signals as dynamic trix together with the left surround channel Ls and the right surround channel Rs are the compatibility Ma¬ are supplied to the third that 'just the factor to the left Korrektur¬ ml Reviewed center signal is used to calculate the left compatible signal Lc This is consistent with the above erläu¬ failed compatibility matrix (see equation 2) except for the fact match, and returned um¬.

Also in this embodiment, the left and right correction factor ml, mr be fed as a side information of the circuit 3 for packing the bit stream and recovered by the circuit 6 to extract the bit stream. (See Fig. 2).

After the joint stereo decoding in the block 8 on the one hand, the decoded left channel L 'and the decoded Mit¬ tenkanal C are multiplied by the left correction coefficient ml (by means not shown, multipliers), while an¬ other hand, the decoded center channel C and the decoded right channel R 'with the right correction coefficients mr be assessed before the thus obtained signals together with the two decoded compatible signals LC, Rc' of the inverse compatibility matrix wer¬ 9 supplied for the recovery of the left and right surround channel Ls ', Rs' the.

When referring now to Figures 3a to 3c to be described the third embodiment of the encoder or decoder according to the invention are a left by the circuit 12 and a right dynamic correction factor kl, kr calculated according to the following equations.:

In the above equation again denote a, b and c Fak¬ gates of the compatibility matrix used in the block. 3 With the left and right correction factor kl, kr (not shown mit¬ means of multipliers) are the left and right compatible signal Lc ', Rc' is multiplied at the output of Kompatibilitäts¬ matrix. 3 These correction factors are wie¬ derum fed to block 3 for packing the bit stream, cher wel¬ these correction factors as side information to the coder transmits De¬, which is shown in Fig. 3c.

The block 6 shown there for unpacking the bitstream lie¬ fert turn, the two correction factors kr, kl. The deco¬ ied left and right compatible signal Lc ', Rc' are (by means not shown, multipliers) in each case by the reciprocal 1 / kl; 1 / kr multiplied before the thus weighted signals together with the decoded left and right channels L ', R' and the decoded central channel C of the inverse Kompatiblitätsmatrix are fed to 9 for the recovery of the left and right surround channel Ls ', Rs'.

The embodiment described above refers to the specific application case of an extended multichannel audio coding according to the MPEG-2 standard. For the skilled person it is obvious that the teachings of the present Erfin dung can be used anywhere where at least two signals are combined by means of joint stereo coding into a co¬-founded signal and recovered from this simulated de¬ coded signals with further Signa ¬ len be summarized in a compatibility matrix compatible signals.

In the above described embodiments, the dynamic correction factors are calculated such that, compared with such signals resulting in a conservation of energy of the compatible signals that would be obtained at the compatibility matrix without common Stereoco¬ consolidation by direct application. However, it is also mög¬ Lich, rekturfaktoren other criteria to calculate the dynamic Kor¬ as zoom pull the energy conservation. Spielsweise is used instead of the viewing squared Sig¬ dimensional for the observation of conservation of energy, the use of other exponents as the exponent 2 into consideration.

It is also possible to equalize the signals in terms of their time envelopes together. Briefly, the compatible signals in respect of any associated relevant signal properties by appropriate choice of Korrekturfak¬ gate to be aligned with the signals dung at the applicational the compatibility matrix would result in signals which are not the common Sterocodierung and anschlie¬ sequent decoding have been subjected.

It should also be noted that the teachings of the present Erfin dung is not limited to a specific number of channels, but applies to any multi-channel audio systems.

Claims

claims
1. A method of encoding a plurality of audio signals in which
at least two signals (L, R, C) by joint stereo coding into a common encoded signal (y) are combined,
- the jointly coded signal (y) for providing si¬ mulierter decoded signals (L ', R', C) deco¬ diert is
- the simulated decoded signal (L ', R', C) and at least one additional signal (Ls, Rs) for Schaf¬ evaporation of to existing decoders compatible Sig¬ dimensional (Lc ', Rc') are combined in a compatibility matrix by matrixing, .
characterized by the step:
- dynamic weights either the compatible signals (LC, Rc ') or the simulated decoded signals (L', R ', C) by means of at least one dynamic correction factor (m; m, r; kl, kr) for the compatible signals (Lc ', Rc' to approach) with respect to their associated relevant signal properties to the signals which would arise in direct trix matrixing these at least two signals (L, R, C) and of the further signal (Ls, Rs) by means of this Kompatibilitätsma¬.
2. The method according to claim 1, characterized in that
that the step of dynamically weighting the compati- tiblen signals (Lc ', Rc') or the simulated deco¬-founded signals (L ', R', C) by means of the dynamic correction factor (m; ml, mr; kl, kr) in the way out aus¬ that the compatible signals (Lc ', Rc') are approached with respect to their energy to the energy of the signals an¬ that die¬ in direct matrixing ser at least two signals (L, R, C) and the further signal (Ls, Rs) would arise by means of the compatibility matrix.
3. The method according to claim 1 or 2, characterized gekennzeich¬ net,
that the step of joint stereo coding comprises a joint stereo coding of the left and of the right basic channel (L, R) and the center channel (C), and
that the additional signals to the left and the right surround channel (Ls, Rs), respectively.
4. The method according to claim 3, characterized in that
that the compatibility matrix is ​​as follows:
Lc = aL + bC + c-Ls;
Rc = aR + bC + c-Rs.
wherein (Ls, Rs) represent the left and right surround channels, (L and R) of the left and right basic channels, (C, a, b and c) coefficients of the compatibility matrix and (Lc, Rc) the compatible signals.
5. A method according to any one of claims 1 to 4, characterized in that
that a single dynamic correction factor (m) from the at least two signals (L, R, C), the stereo coding are to be subjected to ge common, and dimensional (of at least one part of the simulated decoded Sig¬ L ', R', C ) is calculated, and
that each of the simulated decoded signals with die¬ sem dynamic correction factor (m) is multiplied before its Matri¬ cation.
6. A method for decoding the coded audio signals in accordance with claim 5 dependent on claim 4, characterized in that
the correction factor () is transmitted to the decoder,
the jointly coded signal (y) of a joint Ste¬ reo-decoding to obtain the decoded lin¬ ken and right basic channel (L 7, R ') and the de¬ encoded center channel (C) is subjected to
the decoded left and right basic channel (L ', R') as well as the decoded central channel (C) are weighted by multiplication by the Kor¬ rekturfaktor, and
the thus weighted signals (L ', mR', C) are subjected together with the compatible signals (Lc, Rc) for Matrizie¬ tion means of an inverse compatibility matrix for the recovery of the right and left Sur- round channel (Rs ', Ls').
7. The method according to claim 6, characterized in that
that the single dynamic correction factor (m) in accordance with the following relation is determined:
wherein (L) and (R) the left and right basic channels, (C) the central channel, (a and b) Koeffezienten the there are suitable patibilitätsmatrix and (L 'and R') by joint stereo coding and joint stereo decoding generated simu¬ profiled decoded right and left basic channels bezeich¬ NEN.
8. The method according to claim 4, characterized in that
that two dynamic correction factors (ml, mr) are determined such that the following equations are satisfied:
| AL + bC + c-Ls |2 = | ml (aL '+ bC) + c-Ls |2
| AR + bC + c-R | mr (aR '+ bC) + c-R | 2 = |2
wherein (Ls, Rs) represent the left and right surround channels, (L and R) of the left and right basic channels, (C, a, b and c) coefficients of the compatibility matrix and (Lc ', Rc') the compatible signals, and
that obtained by joint stereo coding and an¬ closing joint stereo decoding simu¬ profiled decoded left channel (L ') as well as the simulated decoded central channel (C) with one of the Korrektur¬ factors (ml) and through joint -Stereo coding and subsequent joint stereo decoding obtained simu¬ profiled decoded right channel (R ') as well as the decoded central channel simulier¬ te (C) to the other Korrek¬ turfaktor (mr) are weighted before the cation Matri¬ together with the left and right surround channel by means of the compatibility matrix (ls, rs) be subjected to the creation of the compatible signals.
9. A method for decoding the encoded audio signals according to claim 8, characterized in that
the two correction factors (ml, mr) are transmitted to the decoder,
the jointly coded signal (y) of a joint Ste¬ reo-decoding to obtain the decoded lin¬ ken and right basic channel (L ', R') and the de¬ encoded center channel (C) is subjected to
the left decoded fundamental channel (L ') and the deco¬ ied center channel (C) with said one of Korrek¬ turfaktoren (ml) and the decoded central channel (C) as well as the decoded right basic channel (R') with the other correction factor (mr) by Multi¬ plication be weighted, and
the thus weighted signals (mL-L ', mr-R', ml-C, mr-C) together with the compatible signals (Lc ', Rc') for matrixing means of an inverse Kompa¬ tibilitätsmatrix for recovering the left and right surround channel (Rs ', Ls') are subjected.
10. The method according to claim 4, characterized in that two dynamic correction factors (kl, kr) are determined such that the following equations are satisfied:
wherein (Ls, Rs) represent the left and right surround channels, (L and R) of the left and right basic channels, (C, a, b and c) coefficients of the compatibility matrix and (Lc ', Rc') the compatible signals, and
that each one of the compatible signals (Lc ', RC) which are produced by matrixing, by multiplication with one of the correction factors (kl, kr) is weighted.
11. A method for decoding the encoded audio signals according to claim 10, characterized in that
the correction factors (kl, kr) to the decoder übertra¬ gen are
the compatible signals (Lc ', Rc') through the Kor¬ rekturfaktoren (kl, kr) are divided; and
the thus weighted compatible signals (Lc ', Rc 7) together with the by joint stereo decoding of the jointly coded signal (y) derived signals (L', R ', C) an inverse Kompatibili¬ tätsmatrix to create the left and right surround channel (Ls 7, Rs') are subjected.
EP19950907637 1994-03-18 1995-02-02 Process for coding a plurality of audio signals Expired - Lifetime EP0750811B1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
DE4409368 1994-03-18
DE19944409368 DE4409368A1 (en) 1994-03-18 1994-03-18 A method of encoding a plurality of audio signals
PCT/EP1995/000378 WO1995026083A1 (en) 1994-03-18 1995-02-02 Process for coding a plurality of audio signals

Publications (2)

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EP0750811A1 true true EP0750811A1 (en) 1997-01-02
EP0750811B1 EP0750811B1 (en) 1998-03-25

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EP (1) EP0750811B1 (en)
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KR (1) KR0173391B1 (en)
DE (2) DE4409368A1 (en)
WO (1) WO1995026083A1 (en)

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