[Invention Title]

A METHOD AND AN APPARATUS FOR PROCESSING A SIGNAL

[Technical Field] The present invention relates to an apparatus for processing an audio signal and method thereof. Although the present invention is suitable for a wide scope of applications, it is particularly suitable for processing an audio signal received via a digital medium, a broadcast signal or the like.

[Background Art] Generally, in the process for downmixing a plurality of objects into a mono or stereo signal, parameters are extracted from each object signal. Theses parameters include object level information indicating a level of each of the object signals and downmix gain information applied to each of the object signals.

[Disclosure]

[Technical Problem]

However, since a signal configured in a manner that downmix gain information is applied to each object signal in encoding is included in a downmix signal, the downmix gain information transferred to a decoder may correspond to a redundant information.

[Technical Solution] Accordingly, the present invention is directed to an apparatus for processing a signal and method thereof that substantially obviate one or more of the problems due to limitations and disadvantages of the related art. An object of the present invention is to provide an apparatus for processing a signal and method thereof, by which an audio signal can be efficiently decoded according to the environment and use purposes. For this, since a modified signal generated from applying downmix gain information to an object signal is used, downmix gain information is sent in a manner of being included in an extension region of a frame of object information instead of the frame of the object information.

Another object of the present invention is to provide an apparatus for processing a signal and method thereof, by which object level information can be obtained using downmix gain information and modified object level information, in case that a decoder side attempts to obtain an original signal, in a manner that the downmix gain information is included in an extension region of a frame of object information.

[Advantageous Effects]

Accordingly, the present invention provides the following effects or advantages.

First of all, in an apparatus for processing a signal and method thereof according to the present invention, the signal is decoded using object information including modified object level information. Therefore, since the signal can be decoded without using downmix gain information, the present invention is able to raise coding efficiency.

Secondly, in an apparatus for processing a signal and method thereof according to the present invention, downmix gain information is included in an extension region of a frame of object information and then transferred. In case that a decoder side attempts to obtain an original object signal, it is able to calculate the object level information using the downmix gain information and modified object level information. Therefore, a signal can be efficiently decoded according to the environment and use purposes.

[Description of Drawings] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:

FIG. 1 is a schematic diagram of a signal encoding apparatus according to one embodiment of the present invention;

FIG. 2 is a schematic diagram of an object information generating unit according to one embodiment of the present invention; FIG. 3 is a flowchart for a signal encoding method in the object information generating unit shown in FIG. 2;

FIG. 4 is a schematic diagram of an object information generating unit shown in FIG. 2 according to another embodiment of the present invention;

FIG. 5 is a flowchart for a signal encoding method in the signal encoding apparatus shown in FIG. 4;

FIG. 6 is a schematic diagram of a signal decoding apparatus according to another embodiment of the present invention;

FIG. 7 is a schematic diagram of an information processing unit according another embodiment of the present invention; FIG. 8 and FIG. 9 are diagrams of syntax structures according to various embodiments of the present invention;

FIG. 10 is a schematic diagram of a configuration of a product including a modified object level information obtaining unit, downmix gain information obtaining unit, an object level information calculating unit and an object information processing unit according to another embodiment of the present invention; FIG. 11 is schematic diagrams for relations of products including a modified object level information obtaining unit, downmix gain information obtaining unit, an object level information calculating unit and an object information processing unit according to another embodiment of the present invention, respectively; and FIG. 12 is a schematic block diagram of a broadcast signal decoding apparatus including a modified object level information obtaining unit, downmix gain information obtaining unit, an object level information calculating unit and an object information processing unit according to another embodiment of the present invention. [Best Mode] Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings. To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a method of decoding an audio signal comprises receiving (a) a downmix signal being generated by downmixing a plurality of modified object signals, the modified object signals being generated by applying downmix gain information to object signal, (b) object information including the downmix gain information applied to the object signal and modified object level information indicating energy level of the modified object signal, and (c) rendering information to determine output level and position of the object signal which is included in the downmix signal; obtaining the modified object level information from a frame of the object information and downmix gain information from extension region of the object information; generating downmix processing information by using the modified object level information and the rendering information, the downmix processing information in order to allow object panning and object level control of the downmix signal; generating output signal by modifying the downmix signal with the downmix processing information; and generating object level information by applying the downmix gain information to the modified object level information, in order to obtain the object signal.

Preferably, the downmix gain information is included in the extension region of the object information based on downmix gain flag and wherein the downmix gain flag indicates whether the downmix gain information is included in the object information.

Preferably, the downmix gain flag is included in header of the object information.

Preferably, the object level information is not included in the object information.

The object information further includes object gain difference information indicating a ratio of contributing left channel and right channel of a stereo signal, when the downmix signal is a stereo signal. And, the method of decoding an audio signal further comprises generating multichannel information by using the modified object level information and the rendering information, the multi-channel information in order to convert the downmix signal into plural-channel audio signal; and generating multi-channel audio signal by applying the multi-channel information to the output signal. To further achieve these and other advantages and in accordance with the purpose of the present invention, an apparatus for decoding an audio signal comprises a signal receiving unit receiving (a) a downmix signal being generated by downmixing a plurality of modified object signals, the modified object signal being generated by applying downmix gain information to object signal, (b) object information including downmix gain information applied to the object signal and modified object level information indicating energy level of the modified object signal , and (c) rendering information to determine output level and position of the object signal which is included in the downmix signal; a modified object level information obtaining unit obtaining the modified object level information from a frame of the object information; a downmix gain obtaining unit obtaining the downmix gain information from extension region of the object information; an object information processing unit generating downmix processing information and multi-channel information by using the modified object level information and the rendering information, the downmix processing information in order to allow object panning and object level control of the downmix signal, the multi-channel information in order to convert the downmix signal into plural-channel audio signal; an object level information calculating unit calculating object level information by applying the downmix gain information to the modified object level information and outputting the object level information, in order to obtain the object signal; a downmix signal modifying unit generating output signal by modifying the downmix signal with the downmix processing information; and a multi-channel decoding unit generating the multi-channel audio signal by applying the multi-channel information to the output signal.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. [Mode for Invention]

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. First of all, terminologies or words used in this specification and claims are not construed as limited to the general or dictionary meanings and should be construed as the meanings and concepts matching the technical idea of the present invention based on the principle that an inventor is able to appropriately define the concepts of the terminologies to describe the inventor's invention in best way. The embodiment disclosed in this disclosure and configurations shown in the accompanying drawings are just one preferred embodiment and do not represent all technical idea of the present invention. Therefore, it is understood that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents at the timing point of filing this application.

First of all, it is understood that the concept 'coding' in the present invention includes both encoding and decoding.

Secondly, 'information' in this disclosure is the terminology that generally includes values, parameters, coefficients, elements and the like and its meaning can be construed as different occasionally, by which the present invention is non-limited. Stereo signal is taken as an example for a signal in this disclosure, by which examples of the present invention are non-limited. For example, a signal in this disclosure may include a plural channel signal having at least three or more channels.

FIG. 1 is a schematic diagram of a signal encoding apparatus 100 according to one embodiment of the present invention. Referring to FIG. 1 , a signal encoding apparatus 100 includes an object information generating unit 110 and a downmix signal generating unit 120.

The object information generating unit 110 receives inputs of a plurality of object signals Sl to Sn and downmix gain information (DMG) and then generates object information (OI). In this disclosure, an object signal means such a source included in an audio signal as a guitar, a violin, a vocal and the like. Each source is named one object. And, the object information means the information indicating attributes of a plurality of the objects. Moreover, the object information can include object level information indicating a level of an object signal from a plurality of the inputted object signals, and the downmix gain information. Besides, the object information generating unit 110 is able to generate a modified object signal using a plurality of object signals and downmix gain information. In this case, the object information includes modified object level information on the modified object signal instead of the object level information. Details of this process will be explained with reference to FIGs. 2 to 5 later.

The downmix signal generating unit 120 receives inputs of a plurality of the object signals and the downmix gain information and then generates a downmix signal (DMX). In this case, the downmix signal can include a mono or stereo signal, by which examples of the present invention are non-limited.

FIG. 2 shows an object information generating unit 110 according to one embodiment of the present invention.

Referring to FIG. 2, an object information generating unit 110 includes a modified object generating unit 210 and a modified object level information generating unit 220.

The modified object generating unit 210, as shown in FIG. 2, receives inputs of an object signal S ₁ and downmix gain information D ₁ and then generates a modified object

signal S ₁ by applying the downmix gain information D ₁ to the object signal S ₁ . The

modified object signal S ₁ can be represented as Formula 1.

[Formula 1]

S ₁ = D ₁ S ₁

In this case, T is the number that indicates each object signal. For instance, a first object signal can be represented as 5, , a second object signal can be represented as S ₂ , and downmix gain information applied to the first object signal can be represented as /J ₁ .

The modified object level information generating unit 220 estimates and generates modified object level information using a level of the modified object signal.

Object level information (OLD) of the related art is estimated from an object signal S ₁ before downmix gain information is applied. On the contrary, modified object level information (MLOD) according to one embodiment of the present invention is estimated from a modified object signal S ₁ generated from applying downmix gain information to an object signal.

The related art object level information (OLD) estimated from the object signal and the modified object level information (MOLD) estimated from the modified object signal according to one embodiment of the present invention are represented as Formula 2 and Formula 3, respectively, as follows.

[Formula 2]

[Formula 3]

In this case, ' S"' ^m ' indicates an object signal on a sub-band defined by a time slot

'n' and a sub-band 'm'. In this following description, the 'n' and 'm' are omitted from the corresponding expression. As mentioned in the foregoing description, modified object level information

(MOLD) is the information on a modified object signal having downmix gain information applied thereto. And, it will be more efficient in aspect of coding efficiency if a modified object signal is finally reconstructed in decoding. Therefore, object information according to one embodiment of the present invention includes modified object level information (MOLD) on a modified object signal generated from applying downmix gain information to an object signal. And, object level information (OLD) may not be separately transferred.

FIG. 3 is a flowchart for a signal encoding method in the object information generating unit shown in FIG. 2.

Referring to FIG. 3, an object signal and downmix gain information are received

[S310]. A modified object signal is then generated by applying the downmix gain information to the object signal according to Formula 1 [S320]. And, it is able to generate modified object level information from the generated modified object signal according to

Formula 3 [S330].

Moreover, it is able to generate a downmix signal (DMX) using the modified object signal [S340]. The downmix signal can include a simple sum of the modified object signals and can be represented as Formula 4, by which the present invention is non-limited.

[Formula 4]

The object information(OI) is generated by using the modified object signal. The object information can further include inter-object cross correlation information (IOC) indicating whether object signals on two channels have correlation with each other and downmix gain difference information (DCLD) indicating a ratio that an object signal is included in a stereo downmix signal if a downmix signal is the stereo signal.

And, object information (OI) according to one embodiment of the present invention can further include modified object level information (MOLD) indicating a level of a modified object signal generated from applying downmix gain information to an inputted object signal. Besides, in case that the object information (01) includes the modified object level information (MOLD), downmix gain information (DMG) can be included in an extension region of a frame of the object information. Therefore, in an audio signal processing method and apparatus according to one embodiment of the present invention, in case that a decoder side attempts to obtain an original object signal as well as upmixed multi-channel audio signal, it is able to use the object level information (OLD) using downmix gain information (DMG) in a manner that the downmix gain information (DMG) is included in an extension region of a frame. FIG. 4 is a schematic diagram of an object information generating unit 110 according to another embodiment of the present invention.

Referring to FIG. 4, an object information generating unit 110 includes a modified object generating unit 410, a modified object level information generating unit 420 and an object gain difference information generating unit 430. The modified object generating unit 410, as shown in FIG. 4, receives inputs of an object signal S ₁ and downmix gain information D ₁ and then generates a modified object

signal S ₁ by applying the downmix gain information D ₁ to the object signal S ₁ . In case that a downmix signal is generated from object signals, the downmix gain information D ₁ is the value to indicate how much an object signal contributes to a stereo channel and may include a pair of values. In this case, in order to generate a modified object signal, it is able to derive amended downmix gain information (D _{1 1} , D _{2 1} ) to apply a normalized gain

value using the downmix gain information. This can be represented as Formula 5. [Formula 5]

Moreover, in order to generate a modified object signal S ₁ , the amended

downmix gain information D ₁ , and D _{2 1} can be the normalized value represented as

Formula 6. [Formula 6]

The modified object generating unit 410 is able to generate a modified object signal S ₁ using the amended downmix gain information normalized as Formula 6. This can be represented as Formula 7. [Formula 7]

Moreover, modified object signals S ₁ , and S _{2 1} included in a stereo downmix signal can be derived by Formula 8. [Formula 8]

In Formula 8, S _{1 1} and S _{2 1} may be the modified object signals included in left

and right channels ( S ₁ , , S _{2 1} ) of the stereo downmix signal, respectively. They can be

determined by the amended downmix gain information D ₁ , and D ₂ , .

The modified object level information generating unit 420 generates modified object level information (MOLD) by estimating energy level of modified object signal S ₁ .

In case that a generated downmix signal is a stereo signal, the object gain difference information generating unit 430 is further included. The object gain difference information generating unit 430 derives object gain difference information (DCLD) not using the amended downmix gain information D ₁ , and D ₂ , used to generate a modified object

signal but using downmix gain information D ₁ , and Z) ₂ , inputted to the modified object

generating unit 410. The derived object gain difference information (DCLD) is represented as Formula 9, by which examples of the present invention are non-limited. Moreover, it is able to derive object gain difference information (DCLD) using the amended downmix gains Z ⁾ ₁ , and Z ⁾ _{2 (} as well. [Formula 9]

The modified object level information (MOLD) generated by the modified object level information generating unit 420 and the object gain difference information (DCLD) generated by the object gain difference information generating unit 430 can be transferred in a manner of being included in the object information (OI). Meanwhile, the object information (OI) can carry the downmix gain information

(DMG) to a decoder side in case of transmitting the modified object level information (MOLD). In this case, the downmix gain information (DMG) can be included in an extension region of a frame of the object information. In case of attempting to obtain object level information (OLD) as well as the modified object level information (MOLD), it is possible to use the object level information (OLD) using the downmix gain information (DMG). Moreover, the downmix gain information(DMG) comprises downmix gain value to which the object signal is applied and inverse downmix gain value, thereby transmitting an inverse downmix gain value (inverseDMG) or downmix gain value to a decoder side. If the inverse downmix gain is transmitted to a decoder side, to calculate inverse downmix gain value from the transmitted downmix gain information is omitted in a decoder side. In this disclosure, downmix gain information transmitted to a decoder side may include a value of the downmix gain itself or an inverse downmix gain value. FIG. 5 is a flowchart for a signal encoding method in the object information generating unit shown in FIG. 4. Referring to FIG. 5, an object signal and downmix gain information are received [S510]. A modified object signal is then generated by applying the downmix gain information to the object signal according to Formula 7 [S520].

Subsequently, it is able to generate modified object level information (MOLD) and a downmix signal (DMX) using the modified object signal [S530]. The modified object level information (MOLD) indicates energy level of the modified object signal generated from applying the downmix gain information to the object signal. If the modified object level information is included in object information (OI), downmix gain information (DMG) can be included in an extension region of the object information. In this case, in case of attempting to obtain object level information (OLD) as well as the modified object level information (MOLD), it is possible to use the object level information (OLD) using the downmix gain information (DMG).

And, it is able to generate downmix gain difference information (DCLD), as represented as Formula 9, using downmix gain information. In this case, the downmix gain difference information (DCLD) indicates a ratio that a modified object signal is included in each channel of a downmix signal.

Thus, in a signal processing method and apparatus according to another embodiment of the present invention, a modified object signal is generated and used, whereby object level information (OLD) is not transferred to a decoder side. Instead, downmix gain information (DMG), which is made to be included in an extension region of a frame of object information, is available in case of attempting to obtain an original object signal.

FIG. 6 is a schematic diagram of a signal decoding apparatus 600 according to an embodiment of the present invention. Referring to FIG. 6, a signal decoding apparatus 600 includes a signal receiving unit 610, an information processing unit 620, a downmix signal processing unit 630 and a multi-channel decoding unit 640.

The signal receiving unit 610 receives a downmix signal generated from downmixing a plurality of modified object signals, object information (OI) including downmix gain information applied to an object signal and modified object level information indicating an energy level of a modified object signal generated from applying the downmix gain information to the object signal, and rendering information (RI). The object information received by the signal receiving unit 610 can be partitioned into a header and a plurality of frames. In this case, the header includes configuration information identically applicable to whole frames and each of the frames can include object information related to each frame. In addition, the object information further is partitioned into an extension region of the header and an extension region of the frame. Meanwhile, the rendering information may include the information for determining an output level and position of a modified object signal included in a downmix signal. Unlike the object information, the rendering information may not be received from an encoder but can be determined using a signal inputted by a user.

The information processing unit 620 receives inputs of the object information (OI) and the rendering information (RI) and then generates downmix processing information (DPI) and multi-channel information (MI). The downmix processing information allows object panning and object level control of the downmix signal and the multi-channel information is used to generate multi-channel audio signal from the downmix signal.

And, the information processing unit 620 includes a modified object level information obtaining unit 621, a downmix gain information obtaining unit 622 and an object information processing unit 623. The modified object level information obtaining unit 621 is able to obtain the modified object level information from the object information, preferably, from a frame of the object information. The modified object level information is generated by applying the downmix gain information to the object signal in an encoder side. If the modified object level information is included in the object information, the object information may not include object level information indicating a energy level of the object signal.

If the modified object level information (MLOD) is included in the object information (01) instead of the object level information (OLD), a downmix gain (DMG) can be included in an extension region of a frame of the object information [not shown in the drawing]. If the downmix signal is a stereo signal, downmix gain difference information (DCLD) can be further included in the frame of the object information.

The downmix gain information obtaining unit 622 is able to obtain the downmix gain information (DMG) from the object information, preferably, from an extension region of a frame of the object information.

Whether the object information (01) includes the downmix gain (DMG) can be determined based on downmix gain flag information (bsTransmitDMG). Details of this process will be explained with reference to FIG. 9 later.

And, the information processing unit 620 calculates object level information(OLD) by using obtained downmix gain information. Details of this process will be explained with reference to FIG 7 later. The object information processing unit 623 receives the modified object level information and rendering information, and then generates the downmix processing information and the multi-channel information.

The downmix processing information controls object level included in the downmix signal. And, if the downmix signal is a stereo signal, the downmix processing information is used to move a signal on one of two channels of the stereo signal to the other channel (this is called 'panning' in the following description).

Moreover, the object information processing unit 623 generates multi-channel information (MI) for upmixing a downmix signal into a multi-channel signal using the object information (01) further including inter-object cross correlation (IOC) information as well as the modified object level information (MOLD) and the downmix gain difference information (DCLD). However, the object information processing unit 623 does not use downmix gain information because the modified object level information includes an attribute of the downmix gain information.

The multi-channel information (MI) can include inter-channel level difference information (CLD) indicating a level difference between two channel signals, inter-channel correlation (ICC) information indicating correlation between two channel signals and channel prediction coefficient (CPC) information used to generate at least three channels from two channel signals.

The downmix signal processing unit 630 receives inputs of the downmix signal (DMV) and the downmix processing information (DPI) and is then able to generate an output signal. The downmix processing information (DPI) is applied to the downmix signal to pan an object signal (panning) and to control an object level.

The multi-channel decoding unit 640 is able to decode an audio signal having a multi-channel by applying the multi-channel information (MI) to the output signal outputted from the downmix signal processing unit 630. The multi-channel decoding unit 630 generates an audio signal that has at least three multi-channels.

On the other hand, if a final output signal is a signal having a mono or stereo channel, the multi-channel decoding unit 640 is bypassed but the output signal generated from the downmix signal processing unit 630 is outputted intact. FIG. 7 is a schematic diagram of an information processing unit 700 according another embodiment of the present invention.

Referring to FIG. 7, the information processing unit 700 includes a downmix gain information obtaining unit 710, a modified object level information obtaining unit 720, an object level information calculating unit 730 and an object information processing unit 740. Detailed compositions and functions of the downmix gain information obtaining unit 710, the modified object level information obtaining unit 720 and object information processing unit 740 are as good as the former description with reference to FIGs. 2 to 6 and Formulas 1 to 8 and are omitted in the following description.

The object level information calculating unit 730 calculates object level information(OLD) indicating energy level of original object signal and then outputs the calculated object level information, when the downmix gain information obtaining unit 710 obtains the downmix gain information(DMG). The object level information (OLD) is not included in the object information, thereby not being transmitted from an encoder side. The object level information is calculated with the downmix gain information and the modified object level information and is used to reconstruct the original object signal which is input signal inputted into an encoder.

Thus, in case that a decoder side needs to obtain object level information (OLD), an audio signal processing method and apparatus according to another embodiment of the present invention is able to calculate object level information failing to be received from an encoder using the obtained modified object level information and the obtained downmix gain information. Since the previously received informations (downmix gain information, modified object level information) are used, an audio signal processing method and apparatus according to another embodiment of the present invention is able to reduce a transmission bit size. FIG. 8 shows a structure of syntax according to one embodiment of the present invention. Referring to FIG. 8, in case that modified object level information is included in object information, a downmix gain (DMG) is not included in a frame (SAOCFrame()) of the object information but is included in an extension region (SAOCExtensionFrameData(x)) of the frame. Hence, in an audio signal processing method and apparatus unable to obtain information from an extension region of a frame, . a downmix gain is not obtained. In case of an audio signal processing method and apparatus able to obtain information from an extension region of a frame, downmix gain information (DMG) is received to enable a decoder side to calculate object level information (OLD), in order to obtain an original object signal which is an input signal inputted into an encoder. FIG. 9 shows a structure of syntax according to another embodiment of the present invention. Referring to FIG. 9, downmix gain flag information (bsTransmitDMG) indicating whether a downmix gain is included in object information can be included in a header (SAOCSpecificConfigO) of the object information. The downmix gain flag information is non-limited by those shown in FIG. 9 but can be located at any position in a header syntax. The meaning of the downmix gain flag information is shown in Table 1. [Table 1]

Referring to FIG. 9, if downmix gain flag information is set to 1 (bsTransmitDMG = 1), a downmix gain (DMG) is included in object information. The downmix gain can be included in each frame or an extension region of a frame of object information, is non- limited by those shown in FIG. 9, by can be located at any position in a frame syntax. In case that the frame of the object information has an extension region, the downmix gain can be included in the extension region (SAOCExtensionFrame ()).

Thus, in a signal processing method and apparatus according to another embodiment of the present invention, a multi-channel audio signal is decoded by means of using modified object level information (OLD) and an object signal is obtained by means of calculating object level information (OLD) by using the modified object level information (MOLD) and downmix gain information (DMG), according the downmix gain flag information (bsTransmitDMG). Therefore, the present invention enables a signal to be efficiently processed according to an environment and use purpose.

Moreover, downmix gain information can be included in each frame. If a method of generating a downmix signal is uniform within a predetermined time, a single file, a single song or the like, the downmix gain information can be constant within a same interval. In this case, including downmix gain information in a frame at a timing point of applying modified downmix gain information will be more effective than including downmix gain information in each frame. Therefore, a signal processing method/apparatus according to a further embodiment of the present invention can further include downmix gain update flag information (DMG_update_header_flag) indicating whether downmix gain information is updated per frame. The downmix gain update flag information (DMG_update_header_flag) indicates how the downmix gain information is included in the corresponding frame and can be included in header of object information. Moreover, the meaning of the downmix gain update flag information can be represented as Table 2, by which examples of the present invention are non-limited. [Table 2]

Referring to Table 2, if downmix gain update header flag is set to 0, downmix gain information is same in every frame with a uniform value that is not updated. Hence, downmix gain information (DMG) can be included not in frame but in header. If downmix gain update header flag is set to 1, downmix gain frame flag information

(DMG_update_frame_flag) indicating whether downmix gain information is updated per frame can be further included. If the downmix gain frame flag information indicates that corresponding frame includes updated downmix gain information, object information is able to include the updated downmix gain information.

If downmix gain update header flag is set to 2, downmix gain information updated per predetermined frame period set in header can be included. If downmix gain update header flag is set to 3, updated downmix gain information updated per frame is included to be usable.

The downmix gain information should be understood to generally indicate information relevant to downmix gain information for efficient coding as well as a value of the downmix gain information. For instance, in case of using differential coding scheme, a differential value, an interpolation value, an indicator for generating a previous value or the like can be included. In case that downmix gain information is same in every frame, downmix gain information can be included in header without having downmix gain header flag information included in header of a bitstream.

FIG. 10 is a diagram for a configuration of a product including a DMG obtaining unit 1041, a MOLD obtaining unit 1042, an OLD calculating unit 1043 and an object information processing unit 1044 according to one embodiment of the present invention. And, FIG. 11 is a diagram for relations between products including a DMG obtaining unit 1041, a MOLD obtaining unit 1042, an OLD calculating unit 1043 and an object information processing unit 1044 according to one embodiment of the present invention. Referring to FIG. 10, a wire/wireless communication unit 1010 receives a bitstream by wire/wireless communications. In particular, the wire/wireless communication unit 1010 includes at least one of a wire communication unit 1011, an infrared communication unit 1012, a Bluetooth unit 1013 and a wireless LAN communication unit 1014. A user authenticating unit 1020 receives an input of user information and then performs user authentication. The user authenticating unit 1020 can include at least one of a fingerprint recognizing unit 1021, an iris recognizing unit 1022, a face recognizing unit 1023 and a voice recognizing unit 1024. In this case, the user authentication can be performed in a manner of receiving an input of fingerprint information, iris information, face contour information or voice information, converting the inputted information to user information, and then determining whether the user information matches registered user data.

An input unit 1030 is an input device for enabling a user to input various kinds of commands. And, the input unit 1030 can include at least one of a keypad unit 1031, a touchpad unit 1032 and a remote controller unit 1033, by which examples of the input unit 1030 are non-limited.

A signal decoding unit 1040 includes a DMG obtaining unit 1041, an MOLD obtaining unit 1042, a DMG obtaining unit 1042, an OLD calculating unit 1043 and an object information processing unit 1044, which have the same configurations and functions of the former units of the same names in FIGs. 6-7, respectively. And, details of the signal decoding unit 1040 are omitted in the following description.

A control unit 1050 receives input signals from the input devices and controls all processes of the signal decoding unit 1040 and an output unit 1060. As mentioned in the foregoing description, if such a user input as 'on/off' of a phase shift of an output signal, an input/output of metadata, on/off operation of a signal decoding unit and the like is inputted to the control unit 1050 from the input unit 1030, the control unit 1050 decodes a signal using the user input.

And, the output unit 1060 is an element for outputting an output signal and the like generated by the signal decoding unit 1040. The output unit 1060 can include a signal output unit 1061 and a display unit 1062. If an output signal is an audio signal, it is outputted via the signal output unit 1061. If an output signal is a video signal, it is outputted via the display unit 1062. Moreover, if metadata is inputted to the input unit 1030, it is displayed on a screen via the display unit 1062.

FIG. 11 shows relation between terminals or between terminal and server, which correspond to the product shown in FIG. 10.

Referring to FIG. 11 (a), it can be observed that bidirectional communications of data or bitstream can be performed between a first terminal 1110 and a second terminal 1120 via wire/wireless communication units. In this case, the data or bitstream exchanged via the wire/wireless communication unit may include the former data including the modified object level information, downmix gain information, downmix gain flag information and the like of the present invention described with reference to FIGs. 1 to 9. Referring to FIG. ll(b), it can be observed that wire/wireless communications can be performed between a server 1130 and a first terminal 1140.

FIG. 12 is a schematic block diagram of a broadcast signal decoding apparatus 1200 including a DMG obtaining unit 1041, a MOLD obtaining unit 1042, an OLD calculating unit 1043 and an object information processing unit 1044 according to another embodiment of the present invention.

Referring to FIG. 12, a demultiplexer 1212 receives a plurality of data related to a TV broadcast from a tuner 1210. The received data are separated by the demultiplexer 1212 and are then decoded by a data decoder 1230. Meanwhile, the data separated by the demultiplexer 1220 can be stored in such a storage medium 1250 as an HDD.

The data separated by the demultiplexer 1220 are inputted to a signal decoding unit 1240. The signal decoding unit 1240 includes a DMG obtaining unit 1041, a MOLD obtaining unit 1042, an OLD calculating unit 1043 and an object information processing unit 1044 according to one embodiment of the present invention. They have the same configurations and functions of the former units of the same names shown in FIGs. 6-7 and their details are omitted in the following description. The signal decoding unit 1240 decodes a multi-channel audio signal and object signal using the received downmix gain information and modified object level information. If a video signal is inputted, the signal decoding unit 1240 decodes and outputs the video signal. If metadata is generated, the signal decoding unit 1240 outputs the metadata in a text type.

When a video signal is decoded, if an outputted video signal and metadata are generated, an output unit 1270 displays the outputted metadata. The output unit 1270 includes a speaker unit (not shown in the drawing) and outputs a plural channel signal, which is decoded using the inter-channel phase difference information, via the speaker unit included in the output unit 1270. Moreover, the data decoded by the signal decoding unit 1240 can be stored in a storage medium 1250 such as an HDD.

Meanwhile, the signal decoding apparatus 1200 can further include an application manager 1260 capable of controlling a plurality of data received according to an input of information from a user. The application manager 1260 includes a user interface manager 1261 and a service manager 1262. The user interface manager 1261 controls an interface for receiving an input of information from a user. For instance, the user interface manager 1261 is able to control a font type of text displayed on the output unit 1270, a screen brightness, a menu configuration and the like. Meanwhile, if a broadcast signal is decoded and outputted by the signal decoding unit 1240 and the output unit 1270, the service manager 1262 is able to control a received broadcast signal using information inputted by a user. For instance, the service manager 1262 is able to provide a broadcast channel setting, an alarm function setting, an adult authentication function, etc. The data outputted from the application manager 1260 are usable by being transferred to the output unit 1270 as well as the signal decoding unit 1240.

Accordingly, as a signal processing apparatus of the present invention is included in a real product, the present invention uses modified object level information having a downmix gain reflected thereon and transmits the downmix gain by having it included in an extension region of a frame of object information. And, the present invention is able to efficiently process a signal according to ability and use purpose of the audio signal processing apparatus.

The present invention applied decoding/encoding method can be implemented in a program recorded medium as computer-readable codes. And, multimedia data having the data structure of the present invention can be stored in the computer-readable recoding medium. The computer-readable recording media include all kinds of storage devices in which data readable by a computer system are stored. The computer-readable media include ROM, RAM, CD-ROM, magnetic tapes, floppy discs, optical data storage devices, and the like for example and also include carrier-wave type implementations (e.g., transmission via Internet). And, a bitstream generated by the encoding method is stored in a computer-readable recording medium or can be transmitted via wire/wireless communication network.

While the present invention has been described and illustrated herein with reference to the preferred embodiments thereof, it will be apparent to those skilled in the art that various modifications and variations can be made therein without departing from the spirit and scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention that come within the scope of the appended claims and their equivalents. [Industrial Applicability]

Accordingly, the present invention is applicable to encoding and decoding of an audio signal.