JP2004112315A - Digital broadcast signal multiplex transmission apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission apparatus capable of efficiently multiplexing a data broadcast packet on a television broadcast signal and transmitting the resulting signal at an optional transmission rate in response to fluctuations in an amount of packets of the television broadcast signal. <P>SOLUTION: A data broadcast transmission section 15 inserts a rate information packet describing an optional upper limit rate by each data broadcast program between data broadcast packets and gives the resulting packets to a multiplexer 13, and the multiplexer 13 multiplexes the data broadcast packets on the television broadcast signal at an upper limit rate described in the rate information packet without being affected by band variations in television broadcasting and transmits the resulting packet. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a digital broadcast signal multiplex transmission apparatus for performing data broadcasting in a digital broadcasting system such as satellite broadcasting and terrestrial broadcasting.
[0002]
[Prior art]
In recent years, with the establishment of digital broadcasting technology, digital broadcasting has been started in a satellite broadcasting system using a communication satellite or a broadcasting satellite, and a transition to digital broadcasting is also planned in a terrestrial broadcasting system.
The digital broadcasting stations also perform data broadcasting such as text broadcasting in addition to television broadcasting. In the data broadcasting, various information programs are broadcast, and among them, information linked to the television broadcast program and information independent of the television broadcast program are provided.
[0003]
[Problems to be solved by the invention]
By the way, in the above-mentioned broadcasting station, since the multiplexed output rate, that is, the bandwidth of the broadcast wave is fixed in advance, the data to be transmitted by the data broadcast is converted from the multiplexed output rate to the video and audio transmission rate of the television broadcast program. Must be output at a rate less that However, the transmission rates of video and audio change according to programs and video scenes, and when the transmission rates drop sharply, data broadcasting packets may be output from the multiplexer at a high rate. At this time, there is a possibility that a stream that does not conform to the standards and operation regulations regarding data broadcasting may be output.
For this reason, it was not possible to cope with various broadcast program arrangements and operation forms, and as a result, there were restrictions on broadcast program arrangements and operation forms.
An object of the present invention is to enable the second service broadcast packet to be efficiently multiplexed with the first service broadcast signal at an arbitrary transmission rate according to a change in the amount of packets of the first service broadcast signal and to transmit the multiplexed packet. An object of the present invention is to provide a digital broadcast signal multiplex transmission apparatus.
[0004]
[Means for Solving the Problems]
The present invention is configured as follows to achieve the above object.
(1) The multiplexing unit allocates a first service broadcast signal including first service material information indicating a material of the first service broadcast program to at least a part of a predetermined broadcast band and transmits the signal. At the same time, a plurality of pieces of second service material information having a packet structure indicating materials of the second service broadcast program, which are different from the first service broadcast program and have different transmission rates, and control information about the second service broadcast program, are transmitted. The second service broadcast signal including the periodic information of the packet structure shown is allocated to the remaining band not allocated to the first service broadcast signal, and is transmitted at a transmission rate according to the band occupancy of the first service broadcast signal. A rate indicating an arbitrary transmission rate for each second service broadcast program within a transmission rate range for transmitting a second service broadcast signal. Rate information acquiring means for acquiring information, a signal supplying means for storing a predetermined number of packets of the second service broadcast signal in a buffer, and supplying the same to a multiplexing unit in response to a request, and a second service stored in the buffer. Identification means for identifying the contents of each packet of the broadcast signal; and a second service broadcast signal is read from the buffer based on the identification result of the identification means and the rate information obtained by the rate information obtaining means, and the second service broadcast signal is sent to the multiplexing unit. Multiplexing control means for multiplexing the first service broadcast signal with the first service broadcast signal. It should be noted that the rate information indicates an arbitrary transmission rate among the maximum transmission rates conforming to the operating rules for each second service broadcast program.
[0005]
According to the invention of (1), when the bandwidth occupancy of the first service broadcast signal indicates the minimum, the second service is controlled so as to keep the transmission rate compliant with the operation rule based on the rate information acquired from the outside. Since the broadcast signal is multiplexed with the first service broadcast signal and transmitted, optimal data transmission in accordance with the operation rules can be performed.
[0006]
(2) The rate information obtaining means obtains the rate information through communication with a multiplex control unit that controls the multiplexing unit.
According to the invention of (2), since rate information can be obtained by communication with a known device such as a multiplex control unit, it is not necessary to provide a new signal line for obtaining rate information.
[0007]
(3) A second service broadcast signal is generated, and a rate information packet indicating an arbitrary transmission rate for each second service broadcast program is inserted between packets of the second service broadcast signal and transmitted to the multiplexing unit. And a rate information acquisition unit that extracts a rate information packet from the second service broadcast signal.
[0008]
According to the invention of (3), the signal generation unit for generating the second service broadcast signal inserts a rate information packet indicating an arbitrary transmission rate between the packets of the second service broadcast signal, and multiplexes the signal. Therefore, a dedicated signal line for transmitting rate information can be eliminated, and the number of signal lines in the entire system can be reduced accordingly, thereby simplifying the wiring structure of the system. In addition, since the upper limit rate is updated at the timing when the rate information packet is read from the buffer, when the signal generator updates the upper limit rate, the upper limit rate can be updated without causing a time difference on the multiplexing unit side.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram showing an embodiment of an intra-station system to which a digital broadcast signal multiplex transmission apparatus according to the present invention is applied.
As shown in FIG. 1, the system includes encoders (ENC) 11 and 12, a multiplexer (MUX) 13, an encoding and multiplexing control unit (EMC) 14, a data broadcast transmission unit 15, an automatic program transmission control unit. An (APC) 16, an internal clock 17, and a data server (DS) 18 are provided.
[0010]
The encoder 11 compresses and encodes the video signal of the television broadcast program by the MPEG2 encoding method to generate a bit stream, and outputs the bit stream to the multiplexer 13. The encoder 12 compresses and encodes the audio signal of the television broadcast program by an AAC (Advanced Audio Coding) encoding method to generate a bit stream, and outputs the bit stream to the multiplexer 13.
[0011]
The multiplexer 13 multiplexes the outputs of the encoders 11 and 12 and the data broadcast packets output from the data broadcast transmitting unit 15 and transmits the multiplexed data as a transport stream. In addition, based on information output from the coding multiplexing control unit 14, data such as a PMT (Program Map Table) and a PAT (Program Association Table) is generated and multiplexed into a transport stream.
[0012]
The encoding and multiplexing control unit 14 controls the encoders 11 and 12 and the multiplexer 13 based on the instruction information provided from the automatic program transmission control unit 16, the broadcast schedule data, and the organization time measured by the local clock 17. The PMT and PAT include information on a program and information indicating whether or not data for data broadcasting is included in a transport stream.
[0013]
The data broadcast transmitting section 15 transmits a data broadcast packet to the multiplexer 13 based on instruction information provided from the automatic program transmission control section 16. In addition, based on the organization information and the rate information from the data server 18, a data broadcast packet indicating a service program, a packet indicating various service programs and a DII (Download Information Indication) packet including control information related to the program, and an operation rule are provided. A rate information packet indicating the upper limit rate is generated.
[0014]
The automatic program transmission control unit 16 transmits instruction information to the encoding multiplexing unit 14 and the data broadcast transmission unit 15 according to the broadcast schedule data provided from the data server 18 and the program scheduling time measured by the local clock 17. The encoding multiplexing process of the encoding multiplexing unit 14 is controlled, and the sending process of the data broadcast sending unit 15 is controlled.
[0015]
FIG. 2 is a block diagram showing a specific configuration of the multiplexer 13.
The multiplexer 13 includes memory buffers 131 to 133, a packet identification unit 134, a selector 135, a multiplex control unit 136, an upper limit rate detection / null replacement unit 137, and a rate monitoring unit 138, as shown in FIG.
[0016]
The memory buffer 131 temporarily holds a predetermined number of packet strings from the encoder 11. The memory buffer 132 temporarily holds a predetermined number of packet strings from the encoder 12. The memory buffer 133 temporarily holds a predetermined number of packet strings from the data broadcast transmitting unit 15. The packet identification unit 134 identifies the contents of each packet held in the memory buffers 131 to 133.
[0017]
The selector 135 selectively derives the output of each of the memory buffers 131 to 133. The upper limit rate detection / null replacement unit 137 detects a rate information packet from the output of the selector 135, notifies the detection result to the rate monitoring unit 138, and inserts a null packet at the insertion position of the rate information packet to transmit TS information. Is sent out. The rate monitoring unit 138 obtains, for example, the upper limit rate of the data broadcast conforming to the operation regulations from the detection result by the upper limit rate detection / null replacement unit 137, and sets the upper limit rate in the multiplex control unit 136.
The multiplexing control unit 136 controls reading of the packets held in each of the memory buffers 131 to 133 based on the identification result of the packet identification unit 134 and the upper limit rate set by the rate monitoring unit 138, and switches the selector 135. Perform control.
[0018]
Next, the processing operation of the above configuration will be described below.
First, as shown in FIG. 3, the basic concept of transmission is to use the remaining band of the band used for the video / audio of the television broadcast program as the transmission band of the data broadcast. Video / audio in digital broadcasting employs a compression coding technique defined by MPEG2, so that the band for television broadcasting varies depending on the video scene.
[0019]
In particular, when the band for television broadcasting is the narrowest, some data broadcasting programs exceed the upper limit rate at which data broadcasting packets should be transmitted. In data broadcasting, as shown in FIG. 4, the upper limit rate varies depending on the program. Therefore, it is conceivable to share the upper limit rate in the data broadcast transmitting unit 15 and the upper limit rate in the multiplexer 13. FIGS. 5A and 5B show how the multiplexer 13 changes the upper limit rate in this case.
[0020]
5 (a) shows the output of the data broadcast transmitting unit 15, and FIG. 5 (b) shows the output of the multiplexer 13. In each figure, A to H are 1 Mbps data broadcast packets (two services), and a to h are 0. .1 Mbps data broadcast packet (one service). Here, a program schedule is assumed in which the data broadcasting service is changed from two services to one service at a certain time.
[0021]
Here, the data broadcast sending unit 15 describes the upper limit rate of the multiplexer 13 between data broadcast packets, that is, the upper limit rate for each data broadcast service conforming to the operation regulations, according to the rate information and the organization information notified from the data server 18. The inserted rate information packet is output to the multiplexer 13 as a TS. In this case, a rate information packet describing the upper limit rate of the data broadcast packet of the two services is added to the head of the data broadcast packet of the two services, and the rate information packet describing the upper limit rate of the data broadcast packet of the one service is set to one. It is added to the head of the data broadcast packet of the service.
[0022]
The multiplexer 13 inputs the TS from the data broadcast transmitting unit 15 to the memory buffer 133 and sequentially holds a predetermined number of packets. The packet held in the memory buffer 133 is identified by the packet identification unit 134, and the identification result is notified to the multiplex control unit 136. The packets held in the memory buffer 133 are read out by the multiplexing control unit 136 at a transmission rate according to the change in the bandwidth of the television broadcast, and supplied to the selector 135.
[0023]
The rate information packet derived by the selector 135 is detected by the upper limit rate detection / null replacement unit 137, and the detection result is notified to the rate monitoring unit 138. The rate monitoring unit 138 sets the upper limit rate detected by the upper limit rate detection / null replacement unit 137 in the multiplex control unit 136.
[0024]
The multiplexing control unit 136 outputs a DII packet switching timing signal and a data broadcasting packet switching timing signal to the buffer 133 and the selector 135 based on the set upper limit rate and the identification result of the packet identification unit 134. That is, the read control of the memory buffer 133 and the switching control of the selector 135 are executed so that the transmission in conformity with the standard and the operation rule regarding the data broadcasting service is enabled. By this means, it is possible to effectively transmit data broadcast packets up to a maximum of 1 Mbps before a certain switching time and transmit data broadcasting packets up to a maximum of 0.1 Mbps after a switching time, while complying with the operation rules. . In addition, by constructing such a system, it becomes possible to cope with a change in the configuration of an event of the data broadcasting service and a change in transmission within the event, and diversification of a broadcasting form can be realized.
[0025]
As described above, according to the embodiment, when the band occupancy of the television broadcast signal indicates the minimum, the data broadcast signal is multiplexed with the television broadcast signal based on the upper limit rate arbitrarily set by the multiplexer 13. Since the data is transmitted after being transmitted, optimal data transmission according to an arbitrary upper limit rate can be performed.
[0026]
Further, according to the above embodiment, the data broadcast sending unit 15 inserts the rate information packet describing the upper limit rate conforming to the operation rule between the data broadcast packets and transmits the packet to the multiplexer 13. A dedicated signal line for transmitting rate information can be eliminated, and the number of signal lines in the entire system can be reduced accordingly, thereby simplifying the wiring structure of the system. Also, at the timing when the rate information packet is read from the memory buffer 133 in the multiplexer 13, the data broadcast is updated from the rate corresponding to the change in the bandwidth of the television broadcast to the upper limit rate described in the rate information packet. When the sending unit 15 updates the upper limit rate, the upper limit rate can be updated without causing a time difference on the multiplexer 13 side.
[0027]
In the above-described embodiment, an example has been described in which the upper limit rate information for each data broadcast program is received from the data broadcast transmitting unit 15. However, the present invention is not limited to this. Information may be received. In this case, the processing load on the data broadcast transmitting unit 15 can be reduced. Further, since the rate information can be obtained by communication with a known device such as the coding multiplex control device 14, a new signal line is not required for obtaining the rate information.
Further, a maintenance terminal may be connected to the multiplexer 13 to arbitrarily update the upper limit rate. In this case, an interface for connecting between the multiplexer 13 and the maintenance terminal is required, but an optimal data broadcast packet can be transmitted according to the user's preference.
[0028]
Further, in the above-described embodiment, a description has been given of a television broadcast system using a fixed reception service. However, the present invention is also applicable to, for example, a broadcast system for a mobile body using a portable reception terminal or a broadcast system for a portable terminal. Further, the present invention is also applicable to a computer system using a dedicated line network or the Internet.
In addition, the type and configuration of the intra-station system, the type and configuration of the multiplexer, the update procedure of the rate information, the service broadcast other than the data broadcast, and the like can be variously modified and implemented without departing from the gist of the present invention.
[0029]
【The invention's effect】
As described above in detail, according to the present invention, the second service broadcast packet is efficiently converted into the first service broadcast signal at an arbitrary transmission rate in accordance with the change in the packet amount of the first service broadcast signal. It is possible to provide a digital broadcast signal multiplex transmission device capable of multiplexing and transmitting.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of an intra-station system to which a digital broadcast signal multiplex transmission apparatus according to the present invention is applied.
FIG. 2 is a block diagram showing a specific configuration of a multiplexer shown in FIG. 1. FIG. 3 is a timing chart showing a band relationship between a television broadcast signal and a data broadcast signal in the embodiment.
FIG. 4 is an exemplary timing chart showing a band relationship when a data broadcast service program is changed in the embodiment;
FIG. 5 is a timing chart for explaining the processing operation in the embodiment.
[Explanation of symbols]
11, 12 ... Encoder (ENC),
13. Multiplexer (MUX)
14: Encoding multiplex control unit (EMC),
15 ... data broadcast transmission unit,
16. Automatic program transmission control unit (APC)
17 ... clock inside the office,
18. Data server (DS)
131 to 133 ... memory buffer,
134: packet identification unit,
135 ... selector,
136 ... multiplex control unit,
137: Upper limit rate detection / null replacement unit
138 ... Rate monitoring unit.

Claims (4)

A multiplexing unit allocates a first service broadcast signal including first service material information indicating a material of the first service broadcast program to at least a part of a predetermined broadcast band and transmits the signal. A plurality of pieces of second service material information having a packet structure indicating materials of a second service broadcast program having different transmission rates and different from the first service broadcast program, respectively, and control information relating to the second service broadcast program are shown. The second service broadcast signal including the cycle information of the packet structure is allocated to the remaining band not allocated to the first service broadcast signal, and is transmitted at a transmission rate according to the band occupancy of the first service broadcast signal. A digital broadcast signal multiplex transmission device for transmitting,
Rate information acquisition means for acquiring rate information indicating an arbitrary transmission rate for each of the second service broadcast programs within a transmission rate range to transmit the second service broadcast signal;
A signal supply unit that stores the second service broadcast signal in a buffer for a predetermined number of packets, and supplies the second service broadcast signal to the multiplexing unit as required;
Identification means for identifying the content of each packet of the second service broadcast signal stored in the buffer;
The second service broadcast signal is read from the buffer based on the identification result of the identification unit and the rate information acquired by the rate information acquisition unit, and the second service broadcast signal is sent to the multiplexing unit by the first service broadcast signal. And a multiplexing control means for multiplexing the digital broadcast signal with the service broadcast signal. 2. The digital broadcast signal multiplex transmission apparatus according to claim 1, wherein the rate information acquisition unit acquires the rate information by communicating with a multiplex control unit that controls the multiplex unit. The second service broadcast signal is generated, and a rate information packet indicating an arbitrary transmission rate for each of the second service programs is inserted between packets of the second service broadcast signal and transmitted to the multiplexing unit. Further comprising a signal generation unit that performs
2. The digital broadcast signal multiplex transmission apparatus according to claim 1, wherein the rate information acquisition unit extracts a rate information packet from the second service broadcast signal. 4. The digital broadcast signal according to claim 1, wherein the rate information indicates an arbitrary transmission rate among maximum transmission rates conforming to an operation rule for each of the second service broadcast programs. 5. Multiplexing device.

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