KR20100020889A - Method and apparatus for encoding and decoding audio signal - Google Patents

Abstract

PURPOSE: A method and an apparatus for encoding and decoding audio signal are provided to offer the sound with sense of realism by supporting the play of the multi-channel audio signal. CONSTITUTION: A receiver(110) receives one signal among the multi-channel audio signal and the first audio signal. A first encoding unit(120) extracts spatial parameter from the multi-channel audio signal, mixes the multi-channel audio signal, and generates the second audio signal. A secondary symbol stoker(130) encodes at least one of the first and the second audio signal, and generates the encoded audio signal. A multiplexer(140) multiplexes the encoded audio signal as described above and spatial parameter to generate the satellite DMB(Digital Multimedia Broadcasting) stream.

Description

Audio signal encoding / decoding method and apparatus therefor {METHOD AND APPARATUS FOR ENCODING AND DECODING AUDIO SIGNAL}

The present invention relates to a method and apparatus for encoding / decoding an audio signal, and more particularly, to a method and apparatus for encoding / decoding an audio signal capable of supporting reproduction of a multichannel audio signal in a satellite digital multimedia broadcasting service. will be.

The present invention is derived from research conducted as part of IT source technology development by the Ministry of Knowledge Economy and the Ministry of Information and Communication Research and Development. [Task management number: 2008-F-011-01, Task name: Development of next-generation DTV core technology (standardized connection) -Development of glasses-free personal 3D broadcasting technology (continued)].

Digital Multimedia Broadcasting (DMB) is a mobile multimedia broadcasting service that enables users to listen to video and audio without noise in a mobile environment. DMB provides QVGA (Quarter Video Graphics Array) class video and stereo audio because of its ability to listen in mobile environments.

In order to use the DMB service, various types of receivers, such as a mobile phone built-in, a computer mounted type, and a vehicle mounted type, have been manufactured. Most recently manufactured products such as a navigation device and a personal multimedia player (PMP) include a DMB receiving function. As a result, the number of users of DMB services is expected to increase.

Meanwhile, with the development of multimedia encoding technology, the quality of multimedia serviced through a communication network or a broadcasting network is getting higher and higher. Broadcasting, which has evolved from black and white TVs to color TVs, digital TVs and digital HDTVs, is an example of this trend. This trend is not only limited to video, but can also be found in multi-channel audio services such as 4-channel, 5.1-channel, and 7.1-channel through mono to stereo.

In the case of multi-channel audio, the sound can be reproduced not only in front of the listener but also laterally and rearward, so that the speaker can provide more realistic sound than stereo audio installed only in front of the listener.

However, in the existing DMB system, only stereo audio service is provided due to a mobile environment and a bandwidth problem for data transmission.

An object of the present invention is to provide an audio signal encoding apparatus and an audio signal decoding apparatus that can provide realistic sound in a satellite digital multimedia broadcasting service.

In order to achieve the object of the present invention as described above, an audio signal encoding apparatus according to an embodiment of the present invention is to downmix the multi-channel audio signal, the receiver for receiving at least one of a multi-channel audio signal and a first audio signal A first encoder generates a second audio signal and extracts a spatial parameter from the multichannel audio signal, and encodes an encoded audio signal by encoding at least one of the first audio signal and the second audio signal. And a second encoder to generate a satellite digital multimedia broadcasting stream (DMB Stream) by multiplexing the encoded audio signal and the spatial parameter.

In addition, the audio signal decoding apparatus according to an embodiment of the present invention is a demultiplexer for demultiplexing the satellite digital multimedia broadcast stream to extract the encoded audio signal and the spatial parameters related to the audio signal, decoding the encoded audio signal And a second decoder configured to generate a multichannel audio signal based on the decoded audio signal and the spatial parameter.

The audio signal encoding method may further include receiving at least one of a multichannel audio signal and a first audio signal, downmixing the multichannel audio signal to generate a second audio signal, Extracting a spatial parameter from the multichannel audio signal, encoding at least one of the first audio signal and the second audio signal to generate an encoded audio signal, and encoding the encoded audio signal and the spatial parameter Multiplexing to generate a satellite digital multimedia broadcast stream.

The audio signal decoding method according to an embodiment of the present invention includes demultiplexing a satellite digital multimedia broadcasting stream to extract an encoded audio signal and spatial parameters related to the audio signal, and decoding the encoded audio signal. And generating a multichannel audio signal based on the decoded audio signal and the spatial parameter.

According to the present invention, in the satellite digital multimedia broadcasting service, it is possible to provide a realistic sound.

Hereinafter, an apparatus and a method according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing a detailed configuration of an audio signal encoding apparatus according to an embodiment of the present invention.

The audio signal encoding apparatus 100 according to an embodiment of the present invention includes a receiver 110, a first encoder 120, a second encoder 130, and a multiplexer 140. Hereinafter, the function of each component will be described in detail.

The receiver 110 receives at least one of a multichannel audio signal and a first audio signal.

In this case, the first audio signal refers to a general audio signal provided in a satellite DMB service. According to an embodiment of the present invention, the first audio signal may include at least one of a mono audio signal and a stereo audio signal. have.

That is, the receiver 110 according to an embodiment of the present invention may further receive a multichannel audio signal in addition to the general audio signal.

The first encoder 120 downmixes the received multichannel audio signal to generate a second audio signal, and also extracts a spatial parameter from the received multichannel audio signal.

Here, the spatial parameter refers to side information of the generated second audio signal, and refers to information used for upmixing the second audio signal and decoding it into a multichannel audio signal.

That is, the first encoder 120 performs a function of extracting the second audio signal and the spatial parameter which is additional information from the received multichannel audio signal. As described below, the audio signal decoding apparatus reconstructs the multichannel audio signal by using the second audio signal and the spatial parameter.

According to an embodiment of the present invention, the second audio signal may include at least one of a mono audio signal and a stereo audio signal.

That is, the first encoder 120 may downmix the multichannel audio signal into the mono audio signal or downmix the multichannel audio signal into the stereo audio signal.

In addition, according to an embodiment of the present invention, the spatial parameter is selected from among Inter-channel Intensity Difference (IID), Channel Level Differences (CLD), Inter-Channel Coherence or Inter-Channel Correlation (ICC), and Overall Phase Difference (OPD). It may include at least one.

The IID (or CLD) represents an intensity difference depending on the energy level of at least two channel signals included in the multichannel audio signal, and the ICC is between two channel signals according to the similarity of waveforms of at least two channel signals included in the multichannel audio signal. Indicates a degree of correlation. In addition, IPD indicates a phase difference between at least two channel signals included in the multichannel audio signal, and OPD indicates how a phase difference between at least two channel signals included in the multichannel audio signal is distributed between two channels based on a mono signal. Indicates whether it is

In addition, according to an embodiment of the present invention, the first encoder 120 may generate a second audio signal based on a spatial audio coding (SAC) algorithm and extract a spatial parameter. .

In addition, according to an embodiment of the present invention, the first encoder 120 includes an MPEG Surround coding algorithm, a Sound Source Location Cue Coding (SSLCC) algorithm, and a stereo cue coding (Binaural Cue). Coding (BCC) algorithm can be used to generate a second audio signal and extract spatial parameters.

The second encoder 130 encodes at least one of the first audio signal and the second audio signal to generate an encoded audio signal.

Since the audio signal encoding apparatus according to the present invention is used in connection with providing a satellite DMB service, the second encoder 130 encodes at least one of the first audio signal and the second audio signal according to the satellite DMB standard and encodes the encoded audio. Generate a signal.

The multiplexer 140 generates a satellite DMB stream by multiplexing the encoded audio signal and spatial parameters.

According to an embodiment of the present invention, the audio signal encoding apparatus 100 may further include a packetizer (not shown).

The packetizer (not shown) packetizes the encoded audio signal and spatial parameters into Packetized Elementary Stream (PES) packets. In this case, the multiplexer 140 generates a satellite DMB stream by multiplexing the PES packets.

Accordingly, the audio signal encoding apparatus 100 according to an embodiment of the present invention can provide a multi-channel audio service more realistic than a stereo audio service while being compatible with the existing satellite DMB system.

2 is a block diagram illustrating a structure of a satellite DMB service providing apparatus having an audio signal encoding apparatus according to an embodiment of the present invention.

The satellite DMB service providing apparatus 200 according to an embodiment of the present invention includes a video encoder 210, a stereo audio encoder 220, a multichannel audio encoder 230, a PES packetizer 240, a section packet. And a multiplexer 250 and a TS multiplexer 260. Hereinafter, the function of each component will be described in detail.

The video encoder 210 encodes the received video signal. As an example, the video encoder 210 may encode a video signal according to the satellite DMB standard.

The stereo audio encoder 220 encodes the input stereo audio signal. As an example, the stereo audio encoder 220 may encode a stereo audio signal according to the satellite DMB standard. The stereo audio encoder 210 may correspond to the second encoder 130 of FIG. 1.

The multichannel audio encoder 230 encodes an input multichannel audio signal. In this case, the multichannel audio encoder 230 outputs a spatial audio signal for reconstructing the multichannel audio signal and the stereo audio signal downmixed with the multichannel audio signal. The down mixed stereo audio signal is input to the stereo audio encoder 220, and the spatial parameter is input to the PES packetizer 240.

According to an embodiment of the present invention, since the satellite DMB service providing apparatus 200 may receive at least one of a stereo audio signal and a multi-channel audio signal, the satellite DMB service providing apparatus 200 receives only a stereo audio signal. In this case, the stereo audio encoder 220 encodes only the input stereo audio signal, and when the satellite DMB service providing apparatus 200 receives only the multi-channel audio signal, the stereo audio encoder 220 down-mixes the stereo audio. When only the signal is encoded and the satellite DMB service providing apparatus 200 receives both the stereo audio signal and the multi-channel audio signal, the stereo audio encoder 220 receives the received stereo audio signal and the down mixed stereo audio signal. Code everything. Hereinafter, the signal output from the stereo audio encoder 220 is called an encoded stereo audio signal.

The PES packetizer 240 receives an encoded video signal, an encoded stereo audio signal, and a spatial parameter, and packetizes it into a PES packet. The PES packet packetized by the PES packetizer 240 is input to the TS multiplexer 260.

The section packetizer 250 receives program specific information and packetizes it into a PA section (Program Association Section), a PM section (Program Map Section), a CA section (Conditional Access Section), and the like. do.

In addition, the section packetizer 250 may further receive program service information, and packetize it into an SI section (Service Information Section).

The TS (Transport Stream) multiplexer 260 receives a PES packet and a Section packet, packetizes the MPEG-2 TS, and multiplexes it.

In this case, the section packetizer 250 may set the stream type of the spatial parameter to "User Private."

3 is a block diagram showing a detailed configuration of an audio signal decoding apparatus according to an embodiment of the present invention.

The audio signal decoding apparatus 300 according to an embodiment of the present invention includes a receiver 310, a demultiplexer 320, a first decoder 330, and a second decoder 340. Hereinafter, the function of each component will be described in detail.

The receiver 310 receives the satellite DMB stream. The satellite DMB stream received by the receiver 310 may be transmitted by the audio signal encoding apparatus 100 described with reference to FIG. 1.

The demultiplexer 320 demultiplexes the satellite DMB stream and extracts an encoded audio signal and spatial parameters related to the audio signal.

In this case, according to an embodiment of the present invention, the spatial parameter may include at least one of IID, CLD, ICC, and OPD.

The first decoder 330 decodes the encoded audio signal. The decoded audio signal may include at least one of a mono audio signal or a stereo audio signal.

The second decoder 340 generates a multichannel audio signal based on the decoded audio signal and the spatial parameter.

That is, the second decoder 340 restores the multichannel audio signal from the satellite DMB stream by upmixing the decoded audio signal based on the spatial parameter.

According to an embodiment of the present invention, the second decoder 340 may reconstruct the multichannel audio signal based on the SAC algorithm, and the second decoder 340 may further include an MPEG Surround coding algorithm, an SSLCC algorithm, A multichannel audio signal may be generated based on any one of the BCC algorithms.

In addition, according to an embodiment of the present invention, the second decoder 340 may further generate a virtual multichannel audio signal based on the decoded audio signal and the spatial parameter.

The virtual multichannel audio signal refers to a stereo audio signal that can provide a stereoscopic effect similar to a multichannel audio signal such as 4 channels, 5.1 channels, 7.1 channels, etc. by using two speakers.

That is, the second decoder 340 may output at least one of a multichannel audio signal and a virtual multichannel audio signal.

Accordingly, the audio signal decoding apparatus 300 according to an embodiment of the present invention can provide a more realistic multichannel audio service than the stereo audio service.

4 is a block diagram illustrating a structure of a satellite DMB terminal apparatus having an audio signal decoding apparatus according to an embodiment of the present invention.

The satellite DMB terminal device 400 according to an embodiment of the present invention includes a demultiplexer 410, a video decoder 420, a stereo audio decoder 430, and a multichannel audio decoder 440. . Hereinafter, the function of each component will be described in detail.

The demultiplexer 410 receives the satellite DMB bitstream and divides it into a video packet, an audio packet, a spatial parameter packet, a program designation information packet, and the like. The demultiplexer 410 depackets each packet to encode an encoded video signal and encoded audio. Extract signals, spatial parameters, and program specific information.

The video decoder 420 decodes the encoded video signal.

The stereo audio decoder 430 decodes the encoded audio signal. It is assumed that the decoded audio signal is a stereo audio signal.

The multichannel audio decoder 440 generates a multichannel audio signal based on the decoded stereo audio signal and spatial parameters.

In addition, the multichannel audio decoder 440 may further generate a virtual multichannel audio signal based on the decoded stereo audio signal and a spatial parameter.

The user of the satellite DMB terminal device 400 may select and play one of an output stereo audio signal, a multichannel audio signal, and a virtual multichannel audio signal.

5 is a flowchart illustrating an audio signal encoding method according to an embodiment of the present invention.

An audio signal encoding method according to an embodiment of the present invention includes the steps processed in the audio signal encoding apparatus shown in FIG. 1. Therefore, even if omitted below, the above descriptions of the audio signal encoding apparatus of FIG. 1 also apply to the audio signal encoding method according to an embodiment of the present invention.

In operation S510, at least one of a multichannel audio signal and a first audio signal is received.

In operation S520, the second audio signal is generated by downmixing the multichannel audio signal, and a spatial parameter is extracted from the multichannel audio signal.

According to an embodiment of the present invention, the second audio signal may include at least one of a mono audio signal and a stereo audio signal.

According to an embodiment of the present invention, in operation S520, a second audio signal may be generated and a spatial parameter may be extracted based on the SAC algorithm.

According to an embodiment of the present invention, in operation S520, a second audio signal may be generated and a spatial parameter may be extracted based on any one of an MPEG surround coding algorithm, an SSLCC algorithm, and a BCC algorithm.

In operation S530, at least one of the first audio signal and the second audio signal is encoded to generate an encoded audio signal.

In step S540, the encoded audio signal and the spatial parameters are multiplexed to generate a satellite DMB stream.

According to an embodiment of the present invention, the audio signal encoding method may further include packetizing an encoded audio signal and a spatial parameter into a PES packet (not shown). In this case, in step S540, the PES packet may be multiplexed to generate a satellite DMB stream.

6 is a flowchart illustrating an audio signal decoding method according to an embodiment of the present invention.

An audio signal decoding method according to an embodiment of the present invention is composed of steps processed in the audio signal decoding apparatus shown in FIG. Therefore, even if omitted below, the above descriptions of the audio signal decoding apparatus shown in FIG. 3 also apply to the audio signal decoding method according to an embodiment of the present invention.

In step S610, the satellite digital multimedia broadcast stream is demultiplexed to extract the encoded audio signal and spatial parameters related to the audio signal.

According to an embodiment of the present invention, the spatial parameter may include at least one of IID, CLD, ICC and OPD.

In step S620, the encoded audio signal is decoded.

In operation S630, a multichannel audio signal is generated based on the decoded audio signal and the spatial parameter.

According to an embodiment of the present invention, in operation S630, a virtual multi-channel audio signal may be further generated based on the decoded audio signal and the spatial parameter.

In addition, according to an embodiment of the present invention, in step S630, the multi-channel audio signal may be restored based on the SAC algorithm, and further based on one of the MPEG Surround coding algorithm, the SSLCC algorithm, and the BCC algorithm. A channel audio signal can be generated.

In addition, the audio signal encoding method and the audio signal decoding method according to the present invention can be implemented in the form of program instructions that can be executed by various computer means can be recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Examples of program instructions such as magneto-optical, ROM, RAM, flash memory, etc. may be executed by a computer using an interpreter as well as machine code such as produced by a compiler. Contains high-level language codes. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims below, but also by those equivalent to the claims.

1 is a block diagram showing a detailed configuration of an audio signal encoding apparatus according to an embodiment of the present invention.

2 is a block diagram illustrating a structure of a satellite DMB service providing apparatus having an audio signal encoding apparatus according to an embodiment of the present invention.

3 is a block diagram showing a detailed configuration of an audio signal decoding apparatus according to an embodiment of the present invention.

4 is a block diagram illustrating a structure of a satellite DMB terminal apparatus having an audio signal decoding apparatus according to an embodiment of the present invention.

5 is a flowchart illustrating an audio signal encoding method according to an embodiment of the present invention.

6 is a flowchart illustrating an audio signal decoding method according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

110: receiver

120: first encoder

130: second encoder

140: multiplexer

Claims (19)

A receiver configured to receive at least one of a multichannel audio signal and a first audio signal; A first encoder which generates a second audio signal by downmixing the multichannel audio signal, and extracts a spatial parameter from the multichannel audio signal; A second encoder to generate an encoded audio signal by encoding at least one of the first audio signal and the second audio signal; And A multiplexer configured to multiplex the encoded audio signal and the spatial parameter to generate a satellite digital multimedia broadcasting stream (DMB stream); Audio signal encoding apparatus comprising a. The method of claim 1, And the second audio signal comprises at least one of a mono audio signal and a stereo audio signal. The method of claim 1, And the first encoder generates the second audio signal and extracts the spatial parameter based on a spatial audio coding (SAC) algorithm. The method of claim 1, The first encoder uses the MPEG Surround coding algorithm, a Sound Source Location Cue Coding (SSLCC) algorithm, or a Binaural Cue Coding (BCC) algorithm to perform the second operation. An audio signal encoding apparatus characterized by generating an audio signal and extracting the spatial parameter. The method of claim 1, A packetizer configured to packetize the encoded audio signal and the spatial parameter into a packetized elementary stream (PES) packet More, And the multiplexer generates the satellite digital multimedia broadcast stream by multiplexing the packet packet stream. A demultiplexer which demultiplexes the satellite digital multimedia broadcasting stream and extracts an encoded audio signal and spatial parameters related to the audio signal; A first decoder which decodes the encoded audio signal; And A second decoder configured to generate a multichannel audio signal based on the decoded audio signal and the spatial parameter Audio signal decoding apparatus comprising a. The method of claim 6, The second decoding unit And a virtual multichannel audio signal is further generated based on the decoded audio signal and the spatial parameter. The method of claim 6, And the second decoder generates the multichannel audio signal based on a spatial information-based audio coding algorithm. The method of claim 6, And the second decoder generates the multi-channel audio signal by using any one of an MPEG surround coding algorithm, a sound source position cue coding algorithm, and a stereo sound cue coding algorithm. Receiving at least one of a multichannel audio signal and a first audio signal; Downmixing the multichannel audio signal to generate a second audio signal and extracting spatial parameters from the multichannel audio signal; Encoding at least one of the first audio signal and the second audio signal to generate an encoded audio signal; And Generating a satellite digital multimedia broadcasting stream by multiplexing the encoded audio signal and the spatial parameter Audio signal encoding method comprising a. The method of claim 10, And the second audio signal comprises at least one of a mono audio signal and a stereo audio signal. The method of claim 10, The extracting of the spatial parameter may include generating the second audio signal based on a spatial information-based audio encoding algorithm, and extracting the spatial parameter. The method of claim 10, The generating of the second audio signal and extracting the spatial parameter may include generating the second audio signal using any one of an MPEG surround audio encoding algorithm, a sound source position cue encoding algorithm, and a stereo sound cue encoding algorithm, and generating the space. An audio signal encoding method comprising extracting a parameter. The method of claim 10, Packetizing the encoded audio signal and the spatial parameter into a packet unit stream packet More, The generating of the satellite digital multimedia broadcast stream may include generating the satellite digital multimedia broadcast stream by multiplexing the packet packet stream. Demultiplexing the satellite digital multimedia broadcasting stream to extract an encoded audio signal and spatial parameters associated with the audio signal; Decoding the encoded audio signal; Generating a multichannel audio signal based on the decoded audio signal and the spatial parameter Audio signal decoding method comprising a. The method of claim 15, Generating the multichannel audio signal And generating a virtual multichannel audio signal based on the decoded audio signal and the spatial parameter. The method of claim 15, The generating of the multichannel audio signal may include generating the multichannel audio signal based on a spatial information based audio coding algorithm. The method of claim 15, The generating of the multichannel audio signal may include generating the multichannel audio signal using any one of an MPEG surround coding algorithm, a sound source position cue coding algorithm, and a stereo sound cue coding algorithm. 19. A computer readable recording medium having recorded thereon a program for performing the method of any one of claims 10-18.

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