JP2006050387A - Data reproducing method, and data reproducing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that band expansion processing can not be performed by using SBR data in a terminal that has to input presence/absence of the SBR data before decoding coded data since it can not be indicated in header information whether or not the SBR data are contained when transmitting AAC-plus coded data using a TS. <P>SOLUTION: A novel descriptor is defined in a TS for whether or not SBR data are contained and a sampling frequency after band expansion processing is indicated, thereby acquiring information associated with the SBR data before decoding coded data. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention provides a data structure for acquiring a sampling frequency after band expansion processing without directly analyzing audio data when reproducing audio data including auxiliary data for band expansion, a reproducing apparatus for the same, and multiplexing The present invention relates to a conversion device.

  In recent years, with the development of technology for compressing and encoding multimedia data such as moving images and audio, it has become possible to handle multimedia data in a wide range of applications such as broadcasting, storage, and communication. A typical example of audio data encoding is the AAC (Advanced Audio Coding) standard standardized by the Moving Picture Expert Group (MPEG), which is widely used for digital broadcasting or video services on third-generation mobile terminals. in use.

  In the encoding of audio data, generally, the higher the compression rate, the lower the upper limit frequency of the reproduction band and the sound quality deteriorates. This is because sufficient bits are not allocated for encoding high frequency components. Therefore, in order to compensate for the lack of such high frequency components, a technique called SBR (Spectral Band Replication) has been developed that generates a high frequency component by artificially expanding the band. Specifically, the auxiliary information for predicting the high frequency component from the low frequency component is stored in the stream, so that the band expansion process is performed even on the encoded data with the compression rate increased and the bit rate reduced. Can be reproduced with high sound quality. Here, if the AAC encoded data included in one frame of data is called basic data, the frame data is composed of basic data and SBR data. In general, the SBR can reproduce up to twice the bandwidth of the basic data. For example, 32 kHz output data can be obtained from 16 kHz basic data. Note that a coding method in which SBR is added in addition to the conventional AAC is called AAC-plus. Here, when SBR data is not included in the AAC-plus frame, it is decoded as AAC data. Since AAC-plus is compatible with AAC, the AAC-plus decoding means can decode the AAC encoded data. The AAC decoding means can also decode only basic data by skipping AAC-plus SBR data. Strictly speaking, it is necessary to separate MPEG-2 and MPEG-4 AAC-plus, but in the following, both are treated as AAC-plus.

  As mentioned above, AAC-plus is particularly effective at low bit rates, so it is expected to be used for mobile services and is used in third-generation mobile terminals or mobile terrestrial digital broadcasting. Is done. FIG. 1 shows an overview of terrestrial digital broadcasting for mobile use. The broadcast station transmits audio and video data multiplexed in MPEG-2 TS (Transport Stream). TS is a packet sequence of a 188-byte fixed-length packet called a TS packet, and a mobile phone or an in-vehicle terminal receives this TS packet. Here, in TS, in addition to audio and video data, a data unit called a section for storing program information is transmitted, and on the receiving side, the program information in the section is analyzed and then the audio and video are stored. Start receiving TS packets. A section indicating program information is called a PMT (Program Map Table).

  When transmitting AAC or AAC-plus encoded data using TS packets, the encoded data frame is converted into an MPEG-2 Audio Data Transport Stream (ADTS) frame and then transmitted. FIG. 2 shows the data structure of the ADTS frame. Information such as the sampling frequency and the number of channels of audio data stored in the payload is stored in the header portion of the ADTS frame. In the case of AAC-plus, since the sampling frequency of the ADTS header indicates the sampling frequency of the basic data, the sampling frequency after band expansion cannot be acquired from the ADTS header.

  FIG. 3 is a block diagram showing a configuration of a conventional data reproducing apparatus 1000 that separates, decodes and reproduces AAC-plus data transmitted by a TS packet. The data reproduction apparatus 1000 includes multiplexed data separation means 101, fundamental frequency acquisition means 102, decoding means 103, and output means 104.

  The multiplexed data separating means 101 separates the TS packet storing the AAC-plus encoded data from the multiplexed data MuxDat composed of the TS packet sequence, and further separates the header and payload of the ADTS frame. Then, the header Hdr of the ADTS frame is input to the fundamental frequency acquisition unit 102, and the AAC-plus encoded data Cdata is acquired from the ADTS payload and input to the decoding unit 103. The basic frequency acquisition unit 102 acquires the basic frequency FScore that is the sampling frequency of the basic data of AAC-plus from the header Hdr, and inputs the basic frequency FScore to the decoding unit 103. The decoding means 103 decodes the basic data of AAC-plus based on the basic frequency FScore and the number of channels. Here, when SBR data is detected in an AAC-plus frame, band extension processing is performed, and decoded data Ddata after the band extension processing is input to the output means 104. Also, the output frequency FSo is set. When SBR data is detected in an AAC-plus frame, the output frequency FSo is set to twice the basic frequency FScore. When SBR data is not detected, the output frequency FSo is the same as the basic frequency FScore. Set to value. Further, the set output frequency FSo is input to the output means 104. The output means 104 reproduces the decoded data Ddata at the output frequency FSo. Although not shown here, the fundamental frequency acquisition unit 102 also acquires other information necessary for decoding of AAC-plus, such as the number of channels, and reproduction of the decoding result from the ADTS header, and decoding unit 103, and Input to the output means 104.

FIG. 4 is a flowchart showing the operation of the data reproducing apparatus 1000. First, in step S101, the multiplexed data MuxDat is separated, and the header and payload of the ADTS frame are separated. In step S102, the basic frequency FScore is acquired from the header Hdr of the ADTS frame, and the process proceeds to step S103. In step S103, the basic data of AAC-plus is decoded based on the basic frequency FScore and the number of channels. In step S104, it is determined whether SBR data exists in the AAC-plus frame. When it is determined that SBR data exists, the process proceeds to step S105. In step S105, band expansion processing is performed, and in step S106, the output frequency FSo is set to twice the basic frequency FScore. If it is determined in step S104 that there is no SBR data, the process proceeds to step S107, and the output frequency FSo is set to the same value as the fundamental frequency FScore. Finally, in step S108, the decoded data Ddata is reproduced based on the output frequency FSo.
JP 2003-218701 A

  In this way, in the TS packet sequence input to the conventional data reproduction device 1000, it was not possible to determine whether or not SBR data was included without analyzing the encoded data of AAC-plus, Prior to decoding the encoded data, there has been a first problem that the sampling frequency at the time of reproduction cannot be determined.

  Also in a playback device that supports AAC-plus decoding, band extension using SBR data is performed only when information indicating that SBR data is included in the encoded data is indicated separately from the encoded data. Processing was sometimes performed. When such a reproducing apparatus separates and reproduces the conventional TS packet sequence, there is a second problem that the bandwidth expansion process is not performed.

The present invention has been made to solve the above problems.
A data reproduction method according to claim 1 of the present invention includes:
One or more frame data composed of first frame data encoded with audio and second frame data encoded with band expansion information for expanding the reproduction band of the first frame data; A data reproduction method for receiving and reproducing a packet sequence in which at least the audio attribute information is multiplexed,
An attribute acquisition step of separating and analyzing the attribute information from the packet storing the attribute information and acquiring the attribute information;
A separation step of separating the frame data from the packet storing the frame data;
A decoding step of decoding the separated frame data based on the acquired attribute information;
A reproduction step of reproducing the decoding result of the frame data based on the attribute information;
With
The attribute information includes information related to the second frame data.

A data reproduction method according to claim 2 of the present invention includes:
2. The data reproducing method according to claim 1, wherein the attribute information indicates whether the frame data includes the second frame data.

According to a third aspect of the present invention, there is provided a data reproduction method comprising:
2. The data reproduction method according to claim 1, wherein the attribute information indicates band information after the reproduction band is expanded using the second frame data.

According to a fourth aspect of the present invention, a data reproduction method includes:
In the Nth frame data and the N + 1th frame data, when the attribute information is switched, the packet including the last byte of the Nth frame data and the first byte of the N + 1th frame data are changed. 2. The N + 1-th frame data is decoded and reproduced based on the attribute information indicated by the packet storing the attribute information received between the packet and the packet including the packet. This is a data reproduction method.

According to a fifth aspect of the present invention, there is provided a data reproducing device.
One or more frame data composed of first frame data encoded with audio and second frame data encoded with band expansion information for expanding the reproduction band of the first frame data; A data reproducing apparatus for receiving and reproducing a packet sequence in which at least the audio attribute information is multiplexed,
Attribute acquisition means for separating and analyzing the attribute information from the packet storing the attribute information and acquiring the attribute information;
Separating means for separating the frame data from the packet storing the frame data;
Decoding means for decoding the separated frame data based on the acquired attribute information;
Reproduction means for reproducing the decoding result of the frame data based on the attribute information;
With
The attribute information includes information related to the second frame data.

The program according to claim 6 of the present invention is:
A program for performing the data reproduction method according to claim 1 by a computer,
The above program is stored on the computer.
One or more frame data composed of first frame data encoded with audio and second frame data encoded with band expansion information for expanding the reproduction band of the first frame data; A data reproduction method for receiving and reproducing a packet sequence in which at least the audio attribute information is multiplexed,
An attribute acquisition step of separating and analyzing the attribute information from the packet storing the attribute information and acquiring the attribute information;
A separation step of separating the frame data from the packet storing the frame data;
A decoding step of decoding the separated frame data based on the acquired attribute information;
A reproduction step of reproducing the decoding result of the frame data based on the attribute information;
With
The attribute information includes a data reproduction method characterized by including information on the second frame data.

  As described above, according to the present invention, whether or not SBR data is included in an AAC-plus frame in the TS packet sequence, and the sampling frequency after band expansion can be acquired separately from the frame data. Therefore, the sampling frequency at the time of reproduction can be determined prior to frame decoding. In addition, when a TS packet sequence is received by a data reproducing apparatus that performs bandwidth extension processing only when information indicating the presence or absence of SBR data is indicated separately from frame data, bandwidth extension processing can be performed. High value.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 5 is a block diagram showing the configuration of the data reproducing apparatus 2000 of the present invention. The data reproduction device 2000 includes multiplexed data separation means 201, frequency acquisition means 202, decoding means 203, and output means 204. The data reproduction device 2000 is a data reproduction device that separates and reproduces multiplexed data MuxDat composed of a TS packet sequence including at least AAC-plus encoded data. Here, in the multiplexed data MuxDat, information indicating whether or not SBR data exists in the encoded data is indicated separately from the encoded data, and is reproduced prior to decoding of the AAC-plus frame data. It differs from the conventional data reproducing apparatus 1000 in that the sampling frequency can be determined.

  Although the encoding scheme is AAC-plus, other encoding schemes that include data for band expansion in a frame may be used. Further, the multiplexed data MuxDat may include a TS packet for storing encoded data of other media such as a moving image.

  In the TS packet sequence that is input to the data playback device 2000, the presence or absence of SBR data in the AAC-plus frame and the bandwidth extension using a descriptor called a descriptor defined in the MPEG-2 system standard Indicates the sampling frequency after processing. FIG. 6A shows an AAC-plus descriptor and a method for storing the descriptor. First, the presence / absence of SBR data in an AAC-plus frame and the sampling frequency after band expansion processing are indicated by a newly defined AAC-plus descriptor. The AAC-plus descriptor is stored in the PMT. The PMT has two types of areas for storing descriptors, one of which stores descriptors indicating information common to program data such as information related to conditional access, and the other is video and audio. A descriptor indicating information on each medium constituting the program is stored. For this reason, the AAC-plus descriptor is stored in an area for storing the descriptor indicating the information of each medium in the PMT. FIG. 6B shows an example of the syntax of the AAC-plus descriptor. The descriptor_tag indicates the type of information stored in the descriptor. By referring to this field, it can be seen that information related to AAC-plus SBR data is stored in the descriptor. descriptor_length indicates descriptor size information. SBR_present_flag indicates whether or not SBR data is included in the AAC-plus frame. When SBR data is included, extension_sampling_frequency indicates the sampling frequency after band extension. Here, in extension_sampling_frequency, the index number of the sampling frequency may be indicated, and the sampling frequency corresponding to the index number may be acquired from table data defined separately. For example, in the table data, it is defined that the sampling frequency when the index number is 6 is 24 KHz. Finally, reserved is used to extend the syntax in the future. Here, when there is no AAC-plus descriptor, it is assumed that there is no SBR data. Here, extension_sampling_frequency may be omitted, and the sampling frequency after band expansion may be twice the basic frequency indicated in the ADTS header. Further, when the AAC-plus descriptor exists, it is always indicated that the SBR data exists, and SBR_present_flag may be omitted. As described above, the information indicated by the AAC-plus descriptor is characterized in that it is used in combination with the information indicated in the ADTS header. Information such as the sampling frequency of basic data may be included in the AAC-plus descriptor.

  Further, the presence / absence of SBR data or the sampling frequency after band expansion may be indicated using a reserved area of a descriptor defined in the MPEG-2 system standard called an audio stream descriptor.

  As shown in FIG. 6C, the presence / absence of SBR data may be indicated by the header of the ADTS frame. At this time, the presence / absence of SBR is indicated using the private_bit field or home field of the ADTS header. Here, it can be specified that the sampling frequency after band expansion when the SBR is present is twice the fundamental frequency acquired from the fundamental frequency information of the ADTS header. Alternatively, the ADTS header syntax may be expanded, and the sampling frequency after band expansion may be included in the ADTS header.

  In addition, when the information indicated by the AAC-plus descriptor is switched in the TS packet sequence, after the TS packet storing the last byte of the encoded data of AAC-plus in which the information before the switching is valid, and In the TS packet sent before the TS packet that stores the first byte of the AAC-plus encoded data, the information after switching is valid and the information after switching is valid. AAC-plus descriptor indicating that Here, whether or not the information after switching is valid is indicated by setting the current_next_indicator of the PMT to 1. FIG. 7 shows the timing for sending a PMT including the AAC-plus descriptor after switching.

  Below, the function of each component means of the data reproducing apparatus 2000 will be described. The multiplexed data separating means 201 separates the TS packet storing the AAC-plus encoded data from the multiplexed data MuxDat composed of the TS packet sequence, and further separates the header and payload of the ADTS frame. Further, the header Hdr of the ADTS frame is input to the frequency acquisition unit 202, and the AAC-plus encoded data Cdata is acquired from the ADTS payload and input to the decoding unit 203. Also, the descriptor desc, which is the data of the AAC-plus descriptor, is separated from the TS packet storing the PMT and input to the frequency acquisition means 202. The frequency acquisition unit 202 analyzes the descriptor desc, determines whether or not the SAC is included in the AAC-plus frame, and acquires the output frequency FSo after the band expansion when the SBR data is included. Then, the basic frequency FScore that is the sampling frequency of the basic data of AAC-plus is acquired from the header Hdr, and the SBR information SbrInf indicating whether or not SBR data is included and the basic frequency FScore are input to the decoding unit 203, and the output frequency FSo is input to the output means 204. The decoding means 203 decodes the basic data of AAC-plus based on the basic frequency FScore, and further, when the SBR information SbrInf indicates that the SBR data exists, the decoding means 203 converts the SBR data from the AAC-plus frame data. Obtaining and performing the bandwidth expansion processing, the decoded data Ddata after the bandwidth expansion processing is input to the output means 204. The frequency acquisition unit 202 does not input the SBR information SbrInf to the decoding unit 203, and the decoding unit 203 determines whether or not the SAC data is included in the AAC-plus frame. May be performed. Finally, the output means 204 reproduces the decoded data Ddata at the output frequency FSo. Although not shown here, the frequency acquisition unit 202 also acquires other information necessary for decoding of AAC-plus, such as the number of channels, and reproduction of the decoding result from the ADTS header, and outputs the decoding unit 203 and the output. Input to means 204.

  Note that the frequency acquisition means 202 indicates to the decoding means not to perform the band extension processing by indicating that the SBR data does not exist in the SBR information SbrInf even when the AAC-plus descriptor indicates that the SBR data exists. You may instruct. For example, when the remaining amount of the battery is low, it is possible to operate so as not to perform the bandwidth expansion processing even when SBR data exists in order to reduce the power consumption associated with the bandwidth expansion processing.

  FIG. 8 is a flowchart showing the operation of the data reproducing device 2000. Steps for performing the same operations as those in the flowchart showing the operations of the data reproducing device 2000 shown in FIG. First, in step S201, when a TS packet storing a PMT is detected in the TS packet sequence, it is determined whether or not an AAC-plus descriptor is included in the PMT, and when included, the AAC-plus descriptor is analyzed. Then, the presence / absence of SBR data and the output frequency FSo are obtained when SBR data exists. Here, when there is no AAC-plus descriptor in the PMT, it is considered that there is no SBR data. Note that the AAC-plus descriptor information in the PMT is valid only when the current_next_indicator in the PMT is set. Subsequently, in step S101, step S102, and step S103, the basic data of AAC-plus is decoded, and the process proceeds to step S202. In step S202, when it is determined in step S201 that SBR data exists, the process proceeds to step S105, and when it is determined that SBR data does not exist, the process proceeds to step S203. In step S105, band extension processing is performed, and in step S203, the decoded data Ddata is reproduced based on the output frequency FSo acquired in step S201.

  In step S201, once the AAC-plus descriptor is analyzed and information about the SBR data is acquired, the AAC-plus descriptor is analyzed and information is acquired only when the version_number field of the PMT is updated. May be. Here, version_number is a number that increases by one every time information in the PMT is updated.

  In the above description, the case where auxiliary data for band expansion is included in a frame has been described. However, when auxiliary data for extending the number of channels is included in a frame, the same can be handled. The expansion of the number of channels means, for example, that monaural basic data is reproduced as stereo by using auxiliary data for expanding the number of channels. At this time, the band extension information SbrInf corresponds to information indicating whether or not extension information of the number of channels is included, and the output frequency FSo corresponds to the number of channels during reproduction. Here, the data for expanding the band and the data for expanding the number of channels may be handled simultaneously.

  When the received multiplexed data MuxDat is recorded by adding management information including address information for reproducing by jumping from the middle of the multiplexed data MuxDat or playback time information, it is indicated by an AAC-plus descriptor. Information may be included in the management information. Even when AAC-plus encoded data separated from the multiplexed data MuxDat is multiplexed and recorded by a method different from TS, information indicated by the AAC-plus descriptor may be included in the header information. .

(Embodiment 2)
FIG. 9 is a block diagram showing the configuration of the multiplexing apparatus 3000 of the present invention. Multiplexer 3000 encodes audio input data such as PCM (Pulse Code Modulation) data with AAC-plus or AAC, multiplexes and outputs the data, such as bit rate, sampling frequency, and number of channels. It differs from the conventional multiplexing device in that it has a function of automatically switching between AAC-plus encoding and AAC encoding based on the encoding condition. Although the multiplexing method is TS, MP4 (a method based on ISO / IEC 14496-12), a multiplexing method standardized by MPEG, or ASF (Advanced, a multiplexing method developed by Microsoft) Other formats such as (System Format) may be used.

  Below, the function of each means constituting the multiplexing device 3000 will be described. The multiplexing apparatus 3000 includes an input attribute acquisition unit 301, a bandwidth extension determination unit 302, an encoding unit 303, and a multiplexing unit 304.

  An input attribute inInf1 including information indicating the number of channels of input audio data to be encoded, a sampling frequency, an encoding condition, and the like is input to the input attribute acquisition unit 301. Here, the encoding condition includes a bit rate at the time of encoding, the number of channels, a sampling frequency, and the like. The sampling frequency under the encoding condition indicates the sampling frequency of AAC data when encoding with AAC, and indicates the sampling frequency after band expansion when encoding with AAC-plus. The input attribute acquisition unit 301 inputs the encoding condition CodeInf in the input attribute inInf1 to the band extension determination unit 302, and among the information included in the input attribute inInf1, the number of channels of the input audio data, the sampling frequency, and the encoding condition CodeInf The input attribute inInf2, which is information necessary for encoding, is input to the encoding means 303. Band extension determination means 302 analyzes the encoding condition CodeInf, determines whether to encode with AAC or AAC-plus based on a predetermined condition, and encodes the SBR condition SBRcon indicating the determination result. And the output attribute oInf including the encoding condition CodeInf and the SBR condition SBRcon are input to the multiplexing means 304. The encoding unit 303 encodes the input audio data Ain based on the input attribute inInf2 and the SBR condition SBRcon, and inputs the encoded data Cdata to the multiplexing unit 304. The multiplexing means 304 further converts the encoded data Cdata as an ADTS frame into a TS packet and outputs it. At this time, the header of the ADTS frame is created from the output attribute oInf. Whether to include the AAC-plus descriptor in the PMT is also determined based on the output attribute oInf. Note that when multiplexing by a method other than TS such as MP4 or ASF, the output attribute oInf is used when generating header information of AAC or AAC-plus encoded data in the file.

  Hereinafter, the operation of the band extension determination unit 302 will be described in detail. Based on the bit rate, the number of channels, and the sampling frequency indicated in the encoding condition CodeInf, the band extension determination unit 302 determines whether to encode with AAC or AAC-plus. Here, encoding with AAC-plus means including SBR data in an AAC-plus frame. Specifically, the conditions for encoding with AAC-plus are set in advance. When the encoding conditions are within the setting range, encoding is performed with AAC-plus. When the encoding conditions are outside the setting range, AAC-plus is used. Encode with Instead of following the input attribute, encoding may be performed according to the set output condition. FIG. 10 shows an example of setting conditions when encoding with AAC-plus. In this example, when the parameter values of the bit rate, the number of channels, and the output frequency are in the range shown in gray, encoding is performed with AAC-plus. The output frequency indicates the sampling frequency in the encoding condition CodeInf, and the basic frequency indicates the sampling frequency of basic data in AAC-plus. As shown in FIG. 10, for example, when the output frequency is 32 KHz and the number of channels is 1, if the bit rate is in the range from 16 kbps to 64 kbps, encoding is performed with AAC-plus. In addition, if the output frequency is 48 KHz and the number of channels is 2, if the bit rate is in the range from 24 kbps to 80 kbps, encoding is indicated by AAC-plus.

  FIG. 11 is a flowchart showing the operation of the multiplexing apparatus 3000. First, in step S301, the input attribute inInf1 is acquired, and the process proceeds to step S302. In step S302, the encoding condition CodeInf in the input attribute inInf1 is compared with a predetermined condition for encoding with AAC-plus to determine whether or not to encode with AAC-plus. In step S303, it is determined whether or not encoding with AAC-plus is determined in step S302. If it is determined that encoding with AAC-plus is performed, the process proceeds to step S305, and encoding with AAC-plus is performed using SBR data. Turn into. If it is determined not to encode with AAC-plus, the process proceeds to step S304, and encoding is performed with AAC without using SBR data. Finally, in step S306, the encoded data is multiplexed and output.

Whether or not to apply the extension of the number of channels described in the first embodiment may be automatically determined based on the input attribute and the table data, similarly to the bandwidth extension.
(Embodiment 3)
Further, by recording the program for realizing the multiplexing method and the data reproduction method shown in each of the above embodiments on a recording medium such as a flexible disk, the processing shown in each of the above embodiments is performed. It can be easily implemented in an independent computer system.

  FIG. 12 is an explanatory diagram when the multiplexing method and the data reproduction method of each of the above embodiments are implemented by a computer system using a program recorded on a recording medium such as a flexible disk.

  FIG. 12B shows an appearance, a cross-sectional structure, and a flexible disk as seen from the front of the flexible disk, and FIG. 12A shows an example of a physical format of the flexible disk that is a recording medium body. The flexible disk FD is built in the case F, and a plurality of tracks Tr are formed concentrically on the surface of the disk from the outer periphery toward the inner periphery, and each track is divided into 16 sectors Se in the angular direction. ing. Therefore, in the flexible disk storing the program, the program is recorded in an area allocated on the flexible disk FD.

FIG. 12C shows a configuration for recording and reproducing the program on the flexible disk FD. When the program for realizing the multiplexing method and the data reproduction method is recorded on the flexible disk FD, the program is written from the computer system Cs via the flexible disk drive. Further, when the above multiplexing method and data reproducing method for realizing the multiplexing method and data reproducing method by the program in the flexible disk are built in the computer system, the program is read from the flexible disk by the flexible disk drive and stored in the computer system. Forward.
In the above description, a flexible disk is used as the recording medium, but the same can be done using an optical disk. Further, the recording medium is not limited to this, and any recording medium such as an IC card or a ROM cassette capable of recording a program can be similarly implemented.

  The data reproducing apparatus and multiplexing apparatus according to the present invention can be applied to all devices that receive and reproduce encoded data of AAC-plus transmitted by TS, and the effect of bandwidth expansion by AAC-plus is great. This is particularly effective in a mobile device that is expected to be used in a low bit rate environment.

Diagram showing the outline of digital terrestrial broadcasting for mobile Diagram showing the data structure of a conventional ADTS frame Block diagram showing the configuration of a conventional data reproducing apparatus A flowchart showing the operation of a conventional data reproducing apparatus 1 is a block diagram showing a configuration of a data reproducing device according to a first embodiment of the present invention. The figure which shows the data structure of the ADTS frame input into the data reproduction apparatus concerning Embodiment 1 of this invention The figure which shows the data structure of TS input into the data reproduction apparatus concerning Embodiment 1 of this invention The flowchart which shows operation | movement of the data reproduction apparatus concerning Embodiment 1 of this invention. FIG. 2 is a block diagram showing a configuration of a multiplexing device according to a second exemplary embodiment of the present invention. In the multiplexing apparatus concerning Embodiment 2 of this invention, the table which shows the encoding conditions at the time of encoding by AAC-plus Flowchart showing the operation of the multiplexing apparatus according to the second exemplary embodiment of the present invention. Recording medium on which program for realizing data reproducing method and multiplexing method of the present invention is recorded

Explanation of symbols

201 Multiplexed Data Separating Unit 202 Frequency Acquisition Unit 203 Decoding Unit 204 Output Unit 301 Input Attribute Acquisition Unit 302 Band Extension Determination Unit 303 Encoding Unit 304 Multiplexing Unit 2000 Data Reproducing Device 3000 Multiplexing Device

Claims (6)

One or more frame data composed of first frame data encoded with audio and second frame data encoded with band expansion information for expanding the reproduction band of the first frame data; A data reproduction method for receiving and reproducing a packet sequence in which at least the audio attribute information is multiplexed,
An attribute acquisition step of separating and analyzing the attribute information from the packet storing the attribute information and acquiring the attribute information;
A separation step of separating the frame data from the packet storing the frame data;
A decoding step of decoding the separated frame data based on the acquired attribute information;
A reproduction step of reproducing the decoding result of the frame data based on the attribute information;
With
The data reproduction method, wherein the attribute information includes information on the second frame data.   2. The data reproducing method according to claim 1, wherein the attribute information indicates whether the frame data includes the second frame data.   2. The data reproduction method according to claim 1, wherein the attribute information indicates band information after the reproduction band is expanded using the second frame data.   In the Nth frame data and the N + 1th frame data, when the attribute information is switched, the packet including the last byte of the Nth frame data and the first byte of the N + 1th frame data are changed. 2. The N + 1-th frame data is decoded and reproduced based on the attribute information indicated by the packet storing the attribute information received between the packet and the packet including the packet. Data playback method. One or more frame data composed of first frame data encoded with audio and second frame data encoded with band expansion information for expanding the reproduction band of the first frame data; A data reproducing apparatus for receiving and reproducing a packet sequence in which at least the audio attribute information is multiplexed,
Attribute acquisition means for separating and analyzing the attribute information from the packet storing the attribute information and acquiring the attribute information;
Separating means for separating the frame data from the packet storing the frame data;
Decoding means for decoding the separated frame data based on the acquired attribute information;
Reproduction means for reproducing the decoding result of the frame data based on the attribute information;
With
The data reproducing apparatus according to claim 1, wherein the attribute information includes information related to the second frame data. A program for performing the data reproduction method according to claim 1 by a computer,
The above program is stored on the computer.
One or more frame data composed of first frame data encoded with audio and second frame data encoded with band expansion information for expanding the reproduction band of the first frame data; A data reproduction method for receiving and reproducing a packet sequence in which at least the audio attribute information is multiplexed,
An attribute acquisition step of separating and analyzing the attribute information from the packet storing the attribute information and acquiring the attribute information;
A separation step of separating the frame data from the packet storing the frame data;
A decoding step of decoding the separated frame data based on the acquired attribute information;
A reproduction step of reproducing the decoding result of the frame data based on the attribute information;
With
A program for performing a data reproduction method, wherein the attribute information includes information on the second frame data.

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