(19)
(11)EP 1 991 985 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
20.06.2018 Bulletin 2018/25

(21)Application number: 07715471.4

(22)Date of filing:  05.03.2007
(51)International Patent Classification (IPC): 
G10L 19/008(2013.01)
H04S 3/00(2006.01)
H04S 1/00(2006.01)
H04S 7/00(2006.01)
(86)International application number:
PCT/KR2007/001067
(87)International publication number:
WO 2007/102675 (13.09.2007 Gazette  2007/37)

(54)

Method for generating a stereo signal and corresponding medium

Verfahren zum Erzeugen eines Stereo-Signals und zugehöriges Medium

Procédé de génération d'un signal stéréo et support correspondant


(84)Designated Contracting States:
DE FR GB

(30)Priority: 06.03.2006 US 778933 P
30.05.2006 KR 20060049035
10.11.2006 KR 20060111240

(43)Date of publication of application:
19.11.2008 Bulletin 2008/47

(73)Proprietor: Samsung Electronics Co., Ltd.
Suwon-si, Gyeonggi-do, 443-742 (KR)

(72)Inventors:
  • KIM, Jung-Hoe
    Gyeonggi-do 446-712 (KR)
  • OH, Eun-Mi
    Gyeonggi-do 446-712 (KR)
  • CHOO, Ki-Hyun
    Gyeonggi-do 446-712 (KR)
  • MIAO, Lei
    Gyeonggi-do 446-712 (KR)

(74)Representative: Grünecker Patent- und Rechtsanwälte PartG mbB 
Leopoldstraße 4
80802 München
80802 München (DE)


(56)References cited: : 
WO-A1-2005/101370
WO-A2-02/07481
US-A1- 2003 219 130
WO-A1-2005/101371
WO-A2-2005/036925
US-A1- 2005 157 883
  
  • SCHEIRER E.D. ET AL.: 'AUDIOBIFS: Describing Audio Scenes with the MPEG-4 Multimedia Standard' IEE TRANS. ON MULTIMEDIA vol. 1, no. 3, September 1999, pages 237 - 250, XP001011325
  • KRISTOFER KJÖRLING ET AL: "Information on MPEG Surround CE on scalable channel decoding", 76. MPEG MEETING; 03-04-2006 - 07-04-2006; MONTREUX; (MOTION PICTUREEXPERT GROUP OR ISO/IEC JTC1/SC29/WG11),, no. M13261, 30 March 2006 (2006-03-30), XP030041930, ISSN: 0000-0239
  • JUNGHOE KIM ET AL: "CE report on extended channel configuration signaling", 76. MPEG MEETING; 03-04-2006 - 07-04-2006; MONTREUX; (MOTION PICTUREEXPERT GROUP OR ISO/IEC JTC1/SC29/WG11),, no. M13220, 30 March 2006 (2006-03-30), XP030041889, ISSN: 0000-0239
  • PASI OJALA: "New use cases for spatial audio coding", 75. MPEG MEETING; 16-01-2006 - 20-01-2006; BANGKOK; (MOTION PICTUREEXPERT GROUP OR ISO/IEC JTC1/SC29/WG11),, no. M12913, 11 January 2006 (2006-01-11), XP030041582, ISSN: 0000-0240
  
Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


Description

Technical Field



[0001] Embodiments of the present invention relate to audio decoding, and more particularly, to a surround audio decoding method, medium, and system for selectively decoding an audio signal to a stereo signal or a multi-channel signal.

Background Art



[0002] In general, multi-channel audio coding is classified into waveform multi-channel audio coding and parametric multi-channel audio coding. The waveform multi-channel audio decoding includes MPEG-2 MC audio coding, AAC MC audio coding, BSAC/AVS MC audio coding, etc., and typically receives 5 encoded channel signals and outputs 5 decoded channel signals. The parametric multi-channel audio decoding typically includes MPEG surround coding, and a decoding terminal would receive 1 or 2 input encoded channel signals and outputs 6 or 8 decoded multi-channel signals.

[0003] According to an MPEG surround specification, an input encoded signal can be decoded as a multi-channel signal through a first 5-1-5 tree structure, illustrated in FIG. 1A, and a second 5-1-5 tree structure, illustrated in FIG. 1B. Here, the tree structures receive a down-mixed mono signal, i.e., a signal that has been encoded from multi-channel signals and output as a mono signal, and up-mixes the mono signal to multi-channel signals of a Front Left (FL) channel, a Front Right (FR) channel, a Center (C) channel, a Low Frequency Enhancement (LFE) channel, a Back Left (BL) channel, and a Back Right (BR) channel, using combinations of 1-to-2 (OTT) modules. Here, the up-mixing of the mono signal through the stages of OTT modules can be accomplished with previously generated spatial information of Channel Level Differences (CLDs) and/or Inter-Channel Correlations (ICCs), with the CLD being information about an energy ratio or difference between predetermined channels in multi-channels, and with the ICC being information about correlation or coherence corresponding to a time/frequency tile of input signals. With respective CLDs and ICCs, each staged OTT can up-mix a single input signal to respective output signals through each staged OTT.

[0004] However, due to increases in use of mobile applications, rather than the multi-channel signals, a stereo channel structure is more frequently used than the multi-channel structure. Thus, there is a problem in that the conventional tree structures do not provide an easy computational simplified technique for generating just the stereo channels, i.e., all channels must typically be decoded by performing the entire staged decoding of the input down-mixed mono signal. For example, referring to FIG. 1A, in the first 5-1-5 tree structure, the corresponding OTT0 module outputs a signal that includes information for a FL channel signal, a FR channel signal, a C channel signal, and a LFE channel signal, and a signal that includes information for a BL channel signal and a BR channel signal. Meanwhile, referring to FIG. 1B, in the second 5-1-5 tree structure, the corresponding OTT0 module outputs a signal that includes information for the FL channel signal, the BL channel signal, the FR channel signal, and the BR channel signal and a signal that includes information for the C channel signal and the LFE channel signal.

[0005] For this reason, in these 5-1-5 tree structures, the signals output from the corresponding OTTO modules cannot be suitably used for generation of a left and right channel stereo signal. Rather, additional decoding through the remaining OTT modules stages must be performed to ultimately decode the left and right channels, requiring additional computations and resources.

[0006] From Jakka J et al.,"New use cases for spatial audio coding", 75. MPEG MEETING; 16-01-2006 - 20-01-2006; BANGKOK; (MOTION PICTURE EXPERT GROUP OR ISO/IEC JTC1/SC29/WG11), no. M12913, 11 January 2006 (2006-01-11), XP030041582, ISSN: 0000-0240, decoding a down-mixed mono audio signal, received from a multi-channel audio encoder, to a stereo audio signal using Head-Related Transfer Functions (HRTFs) is known.

Disclosure of Invention


Technical Solution



[0007] According to the present invention, a method for generating a stereo signal, as set forth in appended claim 1, and a corresponding medium, as set forth in appended claim 7, are provided.

Description of Drawings



[0008] These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIGS. 1A and 1B illustrate conventional first and second 5-1-5 tree structures for decoding a multi-channel signal from a down-mixed signal, respectively;

FIG. 2A illustrates a stereo signal generating method, according to an embodiment of the present invention;

FIG. 2B illustrates a method for generating spatial information for up-mixing a down-mixed signal to a stereo signal, according to an embodiment of the present invention;

FIG. 3 illustrates a stereo signal spatial information generating component; and

FIG. 4 illustrates a stereo outputting component.


Mode for Invention



[0009] Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. Embodiments are described below to explain the present invention by referring to the figures.

[0010] FIG. 2A illustrates a stereo signal generating method, according to an embodiment of the present invention.

[0011] Referring to FIG. 2A, a desired multi-channel configuration of a decoding terminal is recognized, in operation 200. The desired multi-channel configuration of the decoding terminal may be based on the number of speakers included in the decoding terminal, the locations of operable speakers among the speakers included in the decoding terminal, information for channel signals available in the decoding terminal among multi-channel signals encoded in an encoding terminal, available processing power for decoding an input down-mixed signal, etc., noting that alternative reasons for desiring only a stereo decoded signal are equally available.

[0012] The number of decoding levels may then be determined, e.g., using such an example of the multi-channel configuration of the decoding terminal recognized in operation 200, in operation 210.

[0013] Here, in one example, if it is determined that the number of levels calculated in operation 210 is "1", in operation 220, spatial information for generating a stereo signal can be generated using pre-existing spatial information for decoding of the down-mixed signal to multi-channel signals, e.g., as generated in an encoding terminal, in operation 230. Here, in this example, since the case when the number of levels is "1" corresponds to the case when a single OTT module is used, it may be determined that an output of only a stereo channel is desired. As noted above, the existing spatial information for up-mixing the down-mixed mono signal to multi-channel signals may be Channel Level Differences (CLDs) or Inter-Channel Correlations (ICCs), noting that embodiments of the present invention is not limited to these types of spatial information.

[0014] The CLDs are information about an energy ratio or difference between predetermined channels in multi-channels, and are energy ratios corresponding to a time/frequency tile of input signals. Respective CLDs can be calculated by the following Equation 1, for example.



[0015] Here, x1 and x2 denote signals input to a corresponding 2-to-1 encoder from a subband domain, n denotes a time slot index, m denotes a subband index, and * denotes complex conjugate.

[0016] The ICC is information about correlation or coherence corresponding to a time/frequency tile of input signals, i.e., a similarity between signals.

[0017] Similar to above, respective ICCs can be calculated by the following Equation 2.



[0018] Here, x1 and x2 denote signals input to a corresponding 2-to-1 encoder from a subband domain, n denotes a time slot index, m denotes a subband index, and * denotes complex conjugate.

[0019] If the aforementioned example number of levels is not "1", the input mono signal may, thus, be decoded and output as a multi-channel signal, e.g., according to the multi-channel configuration of the decoding terminal recognized in operation 200, using such existing CLDs and/or ICCs, in operation 260.

[0020] Conversely, if the aforementioned example number of levels is "1", then, the input down-mixed signal can be up-mixed using the below discussed spatial information generated in operation 230 for up-mixing to a stereo signal, in operation 240.

[0021] Successively, temporal processing (TP) or temporal envelope shaping (TES) may then be applied to the up-mixed stereo signal, in operation 250. Here, operation 250 may be omitted in some embodiments.

[0022] FIG. 2B illustrates an operation of generating spatial information for the up-mixing of the down-mixed mono signal to a stereo signal using the pre-existing spatial information for up-mixing the down-mixed mono signal to multi-channel signals, such as for operation 230, according to an embodiment of the present invention.

[0023] Referring to FIG. 2B, a CLD' for generating the stereo signal may be calculated using the pre-existing CLDs of the signal down-mixed from the multi-channel signals, such as generated in an encoding terminal, in operation 232. Here, the CLD is not an energy decibel difference between two channels but an energy ratio between two channels. Thus, in operation 232, when the CLD' is calculated, if a CLD of the OTT1 module illustrated in FIGS. 1A and 1B is "1", the CLD' is set to "1", in one embodiment. Meanwhile if the CLD of the OTT1 module is not "1", the CLD' can be calculated by the following Equation 3, for example.



[0024] Here, PFL denotes energy of a FL channel, PBL denotes energy of a BL channel, PFC denotes energy of a FC channel, PFR denotes energy of a FR channel, and PBR denotes energy of a BR channel. Further, CLD0 denotes such a CLD as that of the OTT0 module illustrated in FIGS. 1A and 1B, and CLD1 denotes such a CLD as that of the OTT1 module illustrated in FIGS. 1A and 1B, for example.

[0025] Then, an ICC' for generating the stereo signal may be calculated using the pre-existing CLDs or ICCs of the signal down-mixed from the multi-channel signals, such as generated in an encoding terminal, in operation 234.

[0026] In one embodiment, in operation 234, the ICC' may be calculated using the techniques described below.

[0027] Firstly, an ICC' may be calculated using linear interpolation. Here, the ICC' can be calculated by the following Equation 4, for example.



[0028] Here, ICCx denotes an ICC of an OTTx module, CLDx denotes a CLD of the OTTx module, and a may be a constant.

[0029] Secondly, a corresponding ICC' may be read using a look-up table. Here, the ICC' can be read by the following Equation 5, for example.



[0030] Here, ICCx denotes an ICC of an OTTx module and CLDx denotes a CLD of the OTTx module.

[0031] The ICC' corresponding to the ICC0, ... , ICCN, CLD0, ... , CLDN may then be searched for and read from a prepared look-up table. However, it is also possible to use only a specific ICCx or CLDx instead of using all of the ICC0, ... , ICCN, CLD0, ... , CLDN.

[0032] Thirdly, the ICC' may be calculated using correlation of ICCs. For example, in the aforementioned second 5-1-5 tree structure, the ICC' may be calculated by the following



[0033] Here, ICCx is an ICC of an OTTx module, CLDx is a CLD of the OTTx module, and a and b may be constants.

[0034] In this example, the equation 6 can be derived using the following Equations 7-12.













[0035] Here, L' denotes a subband signal of a left channel of a target, R' denotes a subband signal of a right channel of the target, C' denotes a subband signal of a center channel of the target, PL' denotes energy of the left channel of the target, PR' denotes energy of the right channel of the target, PC' denotes energy of the center channel of the target, a is a constant, and * denotes complex conjugate. Here, a may be set to "1/squrt(2)" and b may be set to "1", for example.

[0036] The above Equation 6 can be obtained by substituting the Equations 1 through 11 for the Equation 12 using inner product principle.

[0037] FIG. 3 illustrates a spatial information generating component, as a spatial information generator 300, with an up-mixing unit 310, and a TP/TES applying unit 320. Such a configuration can be implemented in cooperation with the aforementioned first and second tree structures of FIGS. 1A and 1B, respectively.

[0038] The spatial information generator 300 generates spatial information for generating the stereo signal, using pre-existing spatial information for the input down-mixed mono signal, e.g., as previously generated during a down-mixing to the mono signal from multi-channel signals in an encoding terminal. Again, though the spatial information has been discussed as being CLDs or ICCs, one is not limited thereto.

[0039] Here, the spatial information generator 300 may include a CLD' calculator 302 and an ICC' calculator 304.

[0040] The CLD' calculator 302 may calculate a CLD' for generating the stereo signal, using pre-existing CLDs of the signal down-mixed from the multi-channel signals, such as generated in an encoding terminal, which may be received through an input terminal IN1, for example. Here, the CLD is not an energy decibel difference between two channels but an energy ratio between two channels. When the CLD' calculator 302 calculates the CLD', if a CLD of the OTT1 module illustrated in FIGS. 1A and 1B is "1", the CLD' is set to "1", in one embodiment. If the CLD of the OTT1 module is not "1", the CLD' can be calculated by the aforementioned Equation 3.

[0041] The ICC' calculator 304 may further calculate an ICC' for generating the stereo signal, using pre-existing CLDs or ICCs of the down-mixed signal, e.g., with the ICCs being received through an input terminal IN2. At this time, the ICC' can be calculated using any of the above techniques describe in Equations 4-12.

[0042] The up-mixing unit 310 may then up-mix a down-mixed signal, e.g., received through an input terminal IN0, to a stereo signal, using the spatial information generated by the spatial information generator 300, such as the CLD' calculated by the CLD' calculator 302 and the ICC' calculated by the ICC' calculator 304.

[0043] FIG. 4 illustrates a component for outputting such a generated stereo signal, according to an embodiment the present invention. Referring to FIG. 4, a down-mixed mono signal m can be up-mixed using the spatial information generated by the spatial information generator 300, such as the CLD' calculated by the CLD' calculator 302 and the ICC' calculated by the ICC' calculator 304, to a left signal (L) and a right signal (R) by an OTT module, so that the stereo signal is generated.

[0044] The TP/TES applying unit 320 illustrated in FIG. 3 may further apply TP or TES to the stereo signal up-mixed by the up-mixing unit 310, for example. The TP/TES applying unit 320 may, thus, output the resultant signal to which the TP or TES is applied, as a left signal and a right signal, e.g., through an output terminal OUT1 and an output terminal OUT2, respectively.

[0045] In addition to the above described embodiments, embodiments of the present invention can also be implemented through computer readable code/instructions in/on a medium, e.g., a computer readable medium, to control at least one processing element to implement any above described embodiment. The medium can correspond to any medium/media permitting the storing and/or transmission of the computer readable code.

[0046] The computer readable code can be recorded/transferred on a medium in a variety of ways, with examples of the medium including magnetic storage media (e.g., ROM, floppy disks, hard disks, etc.), optical recording media (e.g., CD-ROMs, or DVDs), and storage/transmission media such as carrier waves, as well as through the Internet, for example. Here, the medium may further be a signal, such as a resultant signal or bitstream, according to embodiments of the present invention. The media may also be a distributed network, so that the computer readable code is stored/transferred and executed in a distributed fashion. Still further, as only an example, the processing element could include a processor or a computer processor, and processing elements may be distributed and/or included in a single device.

[0047] In a stereo signal generating method, medium, and system, a down-mixed signal can be selectively up-mixed to a stereo signal, by generating spatial information for up-mixing the down-mixed signal to the stereo signal, using spatial information for up-mixing the down-mixed signal to a multi-channel signal.

[0048] Accordingly, since a down-mixed mono signal, e.g., as generated from a down-mixing of multi-channel signals in an encoding terminal, is up-mixed to be suitable for a stereo signal, it is possible to improve tone quality of the resultant stereo signal.

[0049] Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the invention, the scope of which is defined in the claims.


Claims

1. A method for generating a stereo signal from a down-mixed mono signal according to a channel configuration in a decoding terminal, the method, comprising:

receiving, from a bitstream, spatial information including channel level differences, CLDs, and Inter-Channel Correlations, ICCs, each of the CLDs being an energy difference between predetermined channels of a multi-channel signal according to an 5.1 MPEG surround specification, with regard to a time/frequency tile of the down-mixed mono signal, and each of the ICCs being information about correlation or coherence between the predetermined channels of the multi-channel signal, with regard to the time/frequency tile of the down-mixed mono signal, the spatial information being generated when the multi-channel signal is down-mixed into the down-mixed mono signal, wherein the received spatial information is used for up-mixing the down-mixed mono signal into the multi-channel signal other than the stereo signal;

determining whether a decoding level, dl, indicating the channel configuration in the decoding terminal is a stereo channel;

when the decoding level, dl, is the stereo channel, calculating spatial information including a channel level difference, CLD', and an Inter-Channel Correlation, ICC', wherein the CLD' and the ICC' correspond to a single one-to-two, OTT, module for the stereo signal, using the received spatial information, wherein the calculated channel level difference, CLD', indicates an energy difference between a left channel and a right channel, which are included in the stereo signal, and the calculated Inter-Channel Correlation, ICC', indicates a correlation or coherence between the left channel and the right channel of the stereo signal; and

up-mixing the down-mixed mono signal to the stereo signal including the left channel and the right channel, using the calculated spatial information and the single one-to-two, OTT, module for the stereo signal to generate the stereo signal.


 
2. The method of claim 1, wherein the calculating of the spatial information for the up-mixing of the down-mixed mono signal to the stereo signal comprises:

summing an energy sum of a multi-channel input signal corresponding to the left channel with a value obtained by multiplying energy of a front center channel by a predetermined value, as a left channel sum;

summing an energy sum of a multi-channel input signal corresponding to the right channel with a value obtained by multiplying energy of a front center channel by another predetermined value, as a right channel sum; and

generating the spatial information for the up-mixing of the down-mixed mono signal to the stereo signal using a ratio of the left and right channel sums.


 
3. The method of claim 2, wherein in the calculating of the spatial information for the up-mixing of the down-mixed mono signal to the stereo signal, the spatial information for the up-mixing of the down-mixed mono signal to the stereo signal is generated using the following equation:

where PFL denotes energy of a front left, FL, channel, PBL denotes energy of a back left, BL, channel, PFC denotes energy of a front center, FC, channel, PFR denotes energy of a front right, FR, channel, PBR denotes energy of a back right, BR, channel, a and b are constants, and * denotes multiplication.
 
4. The method of claim 1, wherein, in the calculating of the spatial information for the up-mixing of the down-mixed mono signal to the stereo signal, the spatial information for the up-mixing the down-mixed mono signal to the stereo signal is calculated by linear interpolation, using the ICCs between the predetermined channels in the multi-channel input signal.
 
5. The method of claim 4, wherein, in the calculating of the spatial information for the up-mixing of the down-mixed mono signal to the stereo signal, the spatial information for the up-mixing of the down-mixed mono signal to the stereo signal is generated using the following equation:

where ICCx denotes correlation or coherence of an OTTx module, wherein x stands for a or b and an OTT module is a 1-to-2 module, α is a constant, and * denotes multiplication.
 
6. The method of claim 4, wherein, in the calculating of the spatial information for the up-mixing of the down-mixed mono signal to the stereo signal, the spatial information ICC' about the correlation or coherence between the channels of the stereo signal is generated by searching within a table storing spatial information corresponding to the correlation or coherence between the predetermined channels in the multi-channel input signals.
 
7. At least one medium comprising computer readable code to control at least one processing element to implement the method of any one of claims 1 to 6.
 


Ansprüche

1. Verfahren zum Erzeugen eines Stereosignals aus einem abwärtsgemischten Monosignal in Entsprechung zu einer Kanalkonfiguration in einem decodierenden Endgerät, wobei das Verfahren umfasst:

Empfangen, von einem Bitstrom, von Rauminformationen einschließlich von Kanalpegeldifferenzen (CLDs) und Zwischenkanalkorrelationen (ICCs), wobei jede der CLDs eine Energiedifferenz zwischen vorbestimmten Kanälen eines Mehrkanalsignals gemäß einer 5.1 MPEG Surround-Spezifikation angibt, in Bezug auf eine Zeit/Frequenz-Kachel des abwärtsgemischten Monosignals, und jede der ICCs Informationen zu der Korrelation oder Kohärenz zwischen den vorbestimmten Kanälen des Mehrkanalsignals in Bezug auf die Zeit/Frequenz-Kachel des abwärtsgemischten Monosignals angibt, wobei die Rauminformationen erzeugt werden, wenn das Mehrkanalsignal zu dem abwärtsgemischten Monosignal abwärtsgemischt wird, wobei die empfangenen Rauminformationen für das Aufwärtsmischen des abwärtsgemischten Monosignals zu dem Mehrkanalsignal und nicht zu dem Stereosignal verwendet wird,

Bestimmen, ob eine Decodierstufe (dl), die die Kanalkonfiguration in dem decodierenden Endgerät angibt, ein Stereokanal ist,

wenn die Decodierstufe (dl) ein Stereokanal ist, Berechnen von Rauminformationen einschließlich einer Kanalpegeldifferenz (CLD') und einer Zwischenkanalkorrelation (ICC'), wobei die CLD' und die ICC' einem einzelnen One-To-Two (OTT)-Modul für das Stereosignal entsprechen, unter Verwendung der empfangenen Rauminformationen, wobei die berechnete Kanalpegeldifferenz (CLD') eine Energiedifferenz zwischen einem linken Kanal und einem rechten Kanal in dem Stereosignal angibt und wobei die berechnete Zwischenkanalkorrelation (ICC') eine Korrelation oder Kohärenz zwischen dem linken Kanal und dem rechten Kanal des Stereosignals angibt, und

Aufwärtsmischen des abwärtsgemischten Monosignals zu dem Stereosignal mit dem linken Kanal und dem rechten Kanal unter Verwendung der berechneten Rauminformationen und des einzelnen One-To-Two (OTT)-Moduls für das Stereosignal, um das Stereosignal zu erzeugen.


 
2. Verfahren nach Anspruch 1, wobei das Berechnen der Rauminformationen für das Aufwärtsmischen des abwärtsgemischten Monosignals zu dem Stereosignal umfasst:

Summieren einer Energiesumme eines Mehrkanal-Eingangssignals in Entsprechung zu dem linken Kanal mit einem Wert, der durch das Multiplizieren der Energie eines vorderen mittleren Kanals mit einem vorbestimmten Wert erhalten wird, zu einer linken Kanalsumme,

Summieren einer Energiesumme eines Mehrkanal-Eingangssignals in Entsprechung zu dem rechten Kanal mit einem Wert, der durch das Multiplizieren der Energie eines vorderen mittleren Kanals mit einem anderen vorbestimmten Wert erhalten wird, zu einer rechten Kanalsumme, und

Generieren der Rauminformationen für das Aufwärtsmischen des abwärtsgemischten Monosignals zu dem Stereosignal unter Verwendung eines Verhältnisses der linken und rechten Kanalsummen.


 
3. Verfahren nach Anspruch 2, wobei bei dem Berechnen der Rauminformationen für das Aufwärtsmischen des abwärtsgemischten Monosignals zu dem Stereosignal, die Rauminformationen für das Aufwärtsmischen des abwärtsgemischten Monosignals zu dem Stereosignal unter Verwendung der folgenden Gleichung erzeugt werden:

wobei PFL die Energie eines vorderen linken Kanals wiedergibt, PBL die Energie eines hinteren linken Kanals wiedergibt, PFC die Energie eines vorderen mittleren Kanals wiedergibt, PFR die Energie eines vorderen rechten Kanals wiedergibt, PBR die Energie eines hinteren rechten Kanals wiedergibt, a und b Konstanten sind und * eine Multiplikation wiedergibt.
 
4. Verfahren nach Anspruch 1, wobei bei dem Berechnen der Rauminformationen für das Aufwärtsmischen des abwärtsgemischten Monosignals zu dem Stereosignal die Rauminformationen für das Aufwärtsmischen des abwärtsgemischten Monosignals zu dem Stereosignal durch eine lineare Interpolation unter Verwendung der ICCs zwischen den vorbestimmten Kanälen in dem Mehrkanal-Eingangssignal berechnet werden.
 
5. Verfahren nach Anspruch 4, wobei bei dem Berechnen der Rauminformationen für das Aufwärtsmischen des abwärtsgemischten Monosignals zu dem Stereosignal die Rauminformationen für das Aufwärtsmischen des abwärtsgemischten Monosignals zu dem Stereosignal unter Verwendung der folgenden Gleichung erzeugt werden:

wobei ICCx eine Korrelation oder Kohärenz eines OTTx-Moduls wiedergibt, wobei x für a oder b steht und das OTT-Modul ein 1-zu-2-Modul ist, a eine Konstante ist und * eine Multiplikation wiedergibt.
 
6. Verfahren nach Anspruch 4, wobei bei dem Berechnen der Rauminformationen für das Aufwärtsmischen des abwärtsgemischten Monosignals zu dem Stereosignal die Rauminformationen ICC' über die Korrelation oder Kohärenz zwischen den Kanälen des Stereosignals durch das Suchen in einer Tabelle erzeugt werden, die Rauminformationen in Entsprechung zu der Korrelation oder Kohärenz zwischen den vorbestimmten Kanälen in dem Mehrkanal-Eingangssignalen speichert.
 
7. Wenigstens ein Medium mit einem computerlesbaren Code zum Steuern wenigstens eines Verarbeitungselements für das Implementieren des Verfahrens gemäß einem der Ansprüche 1 bis 6.
 


Revendications

1. Procédé de génération d'un signal stéréo à partir d'un signal mono obtenu par mixage réducteur selon une configuration de canal dans un terminal de décodage, le procédé comprenant :

la réception, en provenance d'une séquence binaire, d'information spatiale comprenant des différences de niveau de canal CLD, soit Channel Level Difference, et des corrélations entre canaux ICC, soit Inter-canal Correlation, chacune des CLD étant une différence d'énergie entre des canaux prédéterminés d'un signal multicanal selon une norme 5.1 MPEG surround, par rapport à une mosaïque temps/fréquence du signal mono obtenu par mixage réducteur, et chacune des ICC consiste en de l'information concernant la corrélation ou la cohérence entre les canaux prédéterminés du signal multicanal, par rapport à la mosaïque temps/fréquence du signal mono obtenu par mixage réducteur, l'information spatiale étant générée quand le signal multicanal est produit par mixage réducteur pour fournir le signal mono obtenu par mixage réducteur, dans lequel l'information spatiale reçue est utilisée pour obtenir par mixage augmentateur du signal mono obtenu par mixage réducteur en le signal multicanal autre que le signal stéréo ;

la détermination du fait qu'un niveau de décodage dl, soit decoding level, indiquant la configuration de canal dans le terminal de décodage est ou non un canal stéréo ;

quand le niveau de décodage dl est le canal stéréo, le calcul d'information spatiale incluant une différence de niveau de canal CLD' et une corrélation entre canaux ICC', dans lequel CLD' et ICC' correspondent à un module unique un-à-deux OTT, soit one-to-two, pour le signal stéréo, en utilisant l'information spatiale reçue, dans lequel la différence de niveau de canal CLD' calculée indique une différence d'énergie entre un canal de gauche et un canal de droite, qui sont inclus dans le signal stéréo, et la corrélation entre canaux ICC' calculée indique une corrélation ou une cohérence entre le canal de gauche et le canal de droite du signal stéréo ; et

le mixage augmentateur du signal mono obtenu par mixage réducteur en signal stéréo incluant le canal de gauche et le canal de droite, en utilisant l'information spatiale calculée et le module unique un-à-deux OTT pour le signal stéréo pour générer le signal stéréo.


 
2. Procédé selon la revendication 1, dans lequel le calcul de l'information spatiale pour le mixage augmentateur du signal mono obtenu par mixage réducteur en signal stéréo comprend :

l'addition d'une somme d'énergie d'un signal d'entrée multicanal correspondant au canal de gauche à une valeur obtenue par multiplication de l'énergie d'un canal central avant par une valeur prédéterminée, comme étant une somme de canal de gauche ;

l'addition d'une somme d'énergie d'un signal d'entrée multicanal correspondant au canal de droite à une valeur obtenue par multiplication de l'énergie d'un canal central avant par une autre valeur prédéterminée, comme étant une somme de canal de droite ; et

la génération de l'information spatiale pour le mixage augmentateur du signal mono obtenu par mixage réducteur en signal stéréo en utilisant le ratio des sommes de canal de gauche et de droite.


 
3. Procédé selon la revendication 2, dans lequel, dans le calcul de l'information spatiale pour le mixage augmentateur du signal mono obtenu par mixage réducteur en signal stéréo, l'information spatiale pour le mixage augmentateur du signal mono obtenu par mixage réducteur en signal stéréo est générée en utilisant l'équation suivante :

où PFL désigne l'énergie d'un canal de gauche avant FL, soit Front Left, PBL désigne l'énergie d'un canal de gauche arrière BL, soit Back Left, PFC désigne l'énergie d'un canal central avant FC, soit Front Center, PFR désigne l'énergie d'un canal de droite avant FR, soit Front Right, PBR désigne l'énergie d'un canal de droite arrière BR, soit back right, a et b sont des constantes, et * désigne une multiplication.
 
4. Procédé selon la revendication 1, dans lequel, dans le calcul de l'information spatiale pour le mixage augmentateur du signal mono obtenu par mixage réducteur en signal stéréo, l'information spatiale pour le mixage augmentateur du signal mono obtenu par mixage réducteur en signal stéréo est calculée par interpolation linéaire, en utilisant les ICC entre les canaux prédéterminés dans le signal d'entrée multicanal.
 
5. Procédé selon la revendication 4 dans lequel, dans le calcul de l'information spatiale pour le mixage augmentateur du signal mono obtenu par mixage réducteur en signal stéréo, l'information spatiale pour le mixage augmentateur du signal mono obtenu par mixage réducteur en signal stéréo est générée en utilisant l'équation suivante :

où ICCx désigne une corrélation ou une cohérence d'un module OTTx, dans lequel x désigne a ou b et un module OTT est un module 1-à-2, α est une constante, et * désigne une multiplication.
 
6. Procédé selon la revendication 4, dans lequel, dans le calcul de l'information spatiale pour le mixage augmentateur du signal mono obtenu par mixage réducteur en signal stéréo, l'information spatiale ICC' concernant la corrélation ou la cohérence entre les canaux du signal stéréo est générée en cherchant dans une table où est stockée de l'information spatiale correspondant à la corrélation ou à la cohérence entre les canaux prédéterminés dans les signaux d'entrée multicanaux.
 
7. Au moins un support comprenant un code lisible par un ordinateur pour contrôler au moins un élément de traitement afin de mettre en oeuvre le procédé selon l'une quelconque des revendications 1 à 6.
 




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Cited references

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