JP4160294B2 - Digital broadcast program relay transmission system, broadcast station thereof, and digital broadcast signal synchronization processing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a digital broadcast program relay transmission system used as, for example, a network reception broadcast, its broadcast station, and a digital broadcast signal synchronization processing apparatus.
[0002]
[Prior art]
In recent years, with the establishment of digital broadcasting technology, digital broadcasting has been started in satellite broadcasting systems using communication satellites and broadcasting satellites, and the transition to digital broadcasting is also planned in terrestrial broadcasting systems.
[0003]
In such digital broadcasting, various developments are in progress, and in particular, the construction of a network receiving broadcasting system that connects, for example, a master station and a remote station via a relay line as implemented in conventional analog broadcasting is one issue. It has become.
[0004]
On the other hand, in digital broadcasting, various data services associated with screen subtitles and programs in addition to video and audio, as well as various program material information for system control of remote stations, and other broadcast control information, are converted into baseband video signals. It is also required to multiplex and transmit data packets during the vertical blanking period.
[0005]
By the way, in the remote station, since the video synchronization of the master station is different from the video synchronization of the remote station, a method of using a frame synchronizer to match the video frame cycle of the master station with the video frame cycle of the remote station is used.
[0006]
This generates a write address based on the clock regenerated from the video synchronization signal sent from the master station to the frame memory built in the frame synchronizer installed in the remote station, and the video is stored in the frame memory using this address. This is done by writing a signal, generating a read address by a clock regenerated from the system synchronization signal of the remote station, and reading the video signal written in the frame memory by this address.
[0007]
In this case, since there is a slight difference between the write clock frequency and the read clock frequency, the write phase and the read phase with respect to the frame memory gradually change, and the write phase and the read phase are about once every several hours. The phenomenon of overtaking or overtaking occurs.
[0008]
At this time, in the output image, a frame freeze in which the same frame is output twice or a frame skip in which one frame is skipped occurs.
[0009]
[Problems to be solved by the invention]
When a frame skip occurs in the remote station, for a television image, there is no sense of incongruity due to the instantaneous phenomenon of 1 frame = 1/30 second, but the data superimposed on the vertical blanking period In contrast to skipping the video screen, for example, a part of the caption data is missing and a subtitle display is not performed on the reception screen, which causes a screen abnormality that can be recognized visually. It will be.
[0010]
SUMMARY OF THE INVENTION An object of the present invention is to provide a digital broadcast program relay transmission system capable of effectively dealing with the occurrence of frame skip occurring at the remote station side when performing network reception broadcast, and the broadcast station and digital broadcast thereof. The object is to provide a signal synchronization processing apparatus.
[0011]
[Means for Solving the Problems]
The digital broadcast program relay transmission system according to the present invention provides a first broadcast for transmitting a digital broadcast signal obtained by compression-coding a program information signal having a predetermined transmission block structure into a first broadcast service area based on a program organization time. The first broadcast station is connected to the first broadcast station via a relay line, receives a program information signal sent from the first broadcast station via the relay line, and applies signal processing to the first broadcast station. A digital broadcast program relay transmission system including a second broadcast station that transmits a digital broadcast signal in a second broadcast service area different from the service area,
The first broadcasting station corresponds to the first accompanying information corresponding to the transmission block including information related to the program during a predetermined blanking period in the transmission block of the program information signal and the transmission block preceding the transmission block. An accompanying information transmitting means for inserting the second accompanying information and transmitting it through the relay line is provided, and the second broadcasting station stores one transmission block of the program information signal arriving from the first broadcasting station via the relay line. A memory, first clock reproduction means for inputting a program information signal coming from a first broadcasting station via a relay line, and reproducing a clock signal synchronized with the program information signal, and a storage area in the memory A write address for specifying is generated, and a program information signal arriving from the first broadcasting station via a relay line is written in synchronization with the clock signal reproduced by the first clock reproduction means. Writing means for writing to the memory at a high speed and generating its writing address, second clock reproducing means for reproducing the clock signal of the own station, and second clock reproducing the program information signal written in the memory by the writing means The read means that reads at a read speed synchronized with the clock signal reproduced by the means and generates a read address thereof, the write address generated by the write means, and the read address generated by the read means are compared and written. Determining means for determining whether or not the speed is equal to or higher than the reading speed; and based on the determination result by the determining means, the first accompanying information and the second accompanying information in the program information signal read from the memory Reproduction processing means for selecting any one of them and performing reproduction processing is provided.
[0012]
According to the present invention, the first broadcast station corresponds to the first associated block in the blanking period in the transmission block of the program information signal to be transmitted to the second broadcast station via the relay line. Information is inserted and, for example, second accompanying information corresponding to the transmission block one transmission block before is inserted and transmitted to the second broadcasting station. Then, in the second broadcasting station, the program information signal from the first broadcasting station is written into the memory at a writing speed synchronized with the signal, and is written into the memory at a reading speed synchronized with the clock signal of the second broadcasting station. The program information signal thus read is read out, and it is determined whether or not the transmission block is skipped by comparing the write address with the read address. Then, when a skip occurs, the second accompanying information in the program information signal is reproduced.
[0013]
Therefore, even if a transmission block skip occurs in the second broadcasting station, the second accompanying information inserted in the blanking period of the next transmission block is reproduced, so the accompanying information before skipping and the skipping are performed. The subsequent accompanying information is clearly connected and can be reproduced without causing loss of the accompanying information. Furthermore, the processing load on the second broadcasting station can be kept low because the second broadcasting station does not need to perform response control for skipping.
[0014]
In the above invention, the reproduction processing means manages the first and second auxiliary information from the input program information signal by managing the addresses of the auxiliary information storage means for storing the first and second auxiliary information and the addresses of the auxiliary information storage means. From the accompanying information storage means based on the input control means for extracting and writing the associated information to a predetermined address of the accompanying information storage means and generating the address information, the address information from this input control means and the judgment result by the judging means And an accompanying information reproduction control unit that reads and outputs one of the first and second accompanying information.
[0015]
By doing this, the first and second accompanying information is sequentially written from the input program information signal to a predetermined address of the accompanying information memory, and when it is notified that a frame skip has occurred, The second accompanying information is read out from the second accompanying information existing area in the accompanying information memory and output, and the first accompanying information is read out from the first accompanying information existing area in the accompanying information memory and output at normal times. Therefore, it is possible to output either the first or second accompanying information with a simple memory process. Further, since the first and second accompanying information in the program information signal after the frame skip is continuously stored in the accompanying information memory, the second information in the accompanying information memory is also generated in the second and subsequent frame skips. This can be easily handled by simply reading the second accompanying information from the accompanying information area.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0017]
FIG. 1 is a schematic configuration diagram showing an embodiment of a digital broadcast program relay transmission system according to the present invention.
[0018]
In FIG. 1, reference numeral 10 indicates a master station as a first broadcasting station, and reference numeral 20 indicates a remote station as a second broadcasting station. The master station 10 transmits a digital broadcast signal, that is, a TS from the antenna 11 toward the broadcast service area to which the own station belongs. The remote station 20 is connected to the master station 10 via the broadcast relay network NW. The remote station 20 converts the relay program information transmitted from the master station 10 via the broadcast relay network NW and the program information of the own station into a TS, and directs the TS from the antenna 21 to the broadcast service area to which the own station belongs. And send it out.
[0019]
FIG. 2 is a block diagram showing the configuration of the master station 10.
[0020]
As shown in the figure, the master station 10 is roughly divided into a switcher (SW) 101 that selectively outputs a program information signal having a frame structure, and a video signal as a program information signal output from the switcher 101. The encoder (ENC) 102 that performs variable-length compression coding based on the MPEG2 coding method and converts the data into an MPEG2 transport stream (TS) packet, and a multiplexer (packet-multiplexing various control data on the output TS packet of the encoder 102) MUX) 103.
[0021]
By the way, in this embodiment, the data insertion unit 104 is interposed between the switcher 101 and the encoder 102.
[0022]
Further, a data server (DS) 106 that stores program organization data as a control system, and ANC data as accompanying data such as caption information and broadcast control information related to the program based on the program organization data stored in the data server 106 And an automatic program transmission control device (APC) 107 provided to the data insertion unit 104.
[0023]
The data insertion unit 104 inserts ANC data given from the automatic program switching control device 107 into the vertical blanking period in the field of the video signal output from the switcher 101. Further, the data insertion unit 104 inserts ANC data two fields before in the vertical blanking period in the field of the video signal.
[0024]
The master station also has an output terminal 108 for sending the TS signal output from the multiplexer 13 to the remote station 20 via the broadcast relay network NW, and a baseband video image output from the data insertion unit 104. An output terminal 109 for sending a signal to the remote station 20 via an analog relay line is provided.
[0025]
FIG. 3 is a block diagram showing a configuration of the remote station 20.
[0026]
As shown in the figure, the remote station 20 includes an input video synchronization playback unit 201, a writing unit 202, a write address generation unit 203, a frame memory 204, a system synchronization generation unit 205, and a read address generation unit 206. A reading unit 207, a skip determination unit 208, and a reproduction processing unit 209.
[0027]
First, a video signal that arrives from the master station 10 via the broadcast relay network NW is input to the input video synchronized playback unit 201 and the writing unit 202.
[0028]
The input video synchronization reproduction unit 201 reproduces a clock signal synchronized with the input video signal and outputs it to the write address generation unit 203. The write address generator 203 generates a write address in synchronization with the input clock signal.
[0029]
The writing unit 202 sequentially writes video signals in the frame memory 204 based on the write address generated by the write address generating unit 203.
[0030]
The system synchronization generation unit 205 reads the local station clock signal and outputs it to the address generation unit 206.
[0031]
The read address generator 206 generates a read address in synchronization with the input clock signal.
[0032]
The reading unit 207 sequentially reads the video signals written in the frame memory 204 based on the read address generated by the read address generation unit 206.
[0033]
The skip determination unit 208 compares the write address generated by the write address generation unit 203 and the read address generated by the read address generation unit 206 to determine whether the write address exceeds the read address.
[0034]
Based on the determination result by the skip determination unit 208, the reproduction processing unit 209 determines which one of ANC data in the current field and ANC data two fields before from the vertical blanking period in the video signal read from the frame memory 204. Either one is played back and output.
[0035]
FIG. 4 is a block diagram showing a specific configuration of the reproduction processing unit 209.
[0036]
In FIG. 4, an input control unit 2092, a shared memory 2093, a CPU 2094, and an output control unit 2095 are connected on the data bus 2091.
[0037]
The input control unit 2092 extracts the ANC data of the current field and the ANC data of two fields before from the video signal read from the frame memory 204, transfers it to the appropriate area of the shared memory 2093, and after the transfer ends, The ANC data existing area is notified to the CPU 2094. In addition, the video portion is transferred to the output control unit 2095.
[0038]
The shared memory 2093 has a capacity for storing ANC data for several frames.
[0039]
Based on the notification from the input control unit 2092 and the determination result from the skip determination unit 208, the CPU 2094 captures ANC data from the shared memory 2093 and transfers it to the output control unit 2095.
[0040]
The output control unit 2095 multiplexes the video signal from the input control unit 2092 and the ANC data transferred from the CPU 2094 and outputs it as an output video signal.
[0041]
Next, the processing operation of the above configuration will be described below.
First, the video signal has an interlaced scanning method and a progressive scanning method depending on the screen scanning method. In the interlaced scanning method, a video frame 1 screen is obtained by scanning twice in the first field and the second field as shown in FIG. Is completed. In this case, the ANC data can be superimposed on both the vertical blanking area immediately before the first field and the vertical blanking area immediately before the second field.
[0042]
On the other hand, in the progressive scanning method, a video frame is completed by one scanning. Note that the frame skip phenomenon occurs in units of one frame as in the interlace scanning method. For this reason, in the following description, the case of an interlaced scanning method signal will be described. However, the case of the progressive scanning method can be completely applied by handling on the scale of frame units.
[0043]
The data insertion unit 104 of the master station 10 superimposes the ANC data of the current field in the vertical blanking region of the video signal and superimposes the ANC data of two fields before. As shown in FIG. 6, a frame at a certain time point is assumed to be the Mth frame, the number of the ANC data packet to be superimposed on the vertical blanking area immediately before the first field is (ANC # n), and the second field. The number of the ANC data packet to be superimposed on the vertical blanking area immediately before (ANC # n + 1), and the number of the ANC data packet to be superimposed on the vertical blanking area immediately before the first field of the next M + 1 frame (ANC # n + 2), the number of the ANC data packet superimposed on the vertical blanking area immediately before the second field is (ANC # n + 3), and so on.
[0044]
In the present embodiment, the data insertion unit 104 adds an ANC data packet (ANC # n) to be superimposed on the vertical blanking region immediately before the first field of the Mth frame to the first of the M + 1th frame after one frame. It is also superimposed again on the vertical blanking area immediately before the field.
[0045]
Subsequently, the ANC data packet (ANC # n + 1) to be superimposed on the vertical blanking area immediately before the second field is superimposed again on the vertical blanking area immediately before the second field of the M + 1 frame after one frame.
[0046]
In this manner, the data insertion unit 104 multiplexes the same ANC data again after one frame, so that both the original ANC data and the ANC data one frame before are arranged and superimposed for each frame. As a result of such a multiplex operation, the ANC data packet corresponding to the lost frame is also present in the skipped next frame even when a frame skip occurs once every several hours in the synchronizer on the remote station 20 side. Therefore, it is possible to output an ANC data packet corresponding to a lost frame using this, and data continuity is ensured by simple memory processing.
[0047]
On the other hand, in the remote station 20, the video signal arriving from the master station 10 via the broadcast relay network NW is based on a write address synchronized with the clock of the video signal generated by the write address generating unit 203 in the writing unit 202. One frame is written in the frame memory 204. Then, the reading unit 207 reads the video signal written in the frame memory 204 based on the reading address synchronized with the local station clock generated by the reading address generation unit 207.
[0048]
The write address generated by the write address generation unit 203 and the read address generated by the read address generation unit 206 are compared by the skip determination unit 208, and it is determined from this comparison result whether or not a skip has occurred. The determination result is notified to the reproduction processing unit 209.
[0049]
In the reproduction processing unit 209, the ANC data packet of the current field and the ANC data packet of two fields before in the video signal for one frame read from the frame memory 204 are stored in the shared memory 2093 by the input control unit 2092. Transfer sequentially to the area. When the transfer of the ANC data is completed, the input control unit 2092 notifies the CPU 2094 of the existing area of the ANC data.
[0050]
In response to the determination result of the skip determination unit 208, the CPU 2094 reads an ANC data packet corresponding to the current field from the shared memory 2093 and transfers it to the output control unit 2095 when no skip has occurred. On the other hand, when a skip occurs as shown in FIG. 6, first, the ANC data packet ANC # n of the first field of the (M + 1) th frame is read from the shared memory 2095, and then the ANC data of the second field of the (M + 1) th frame. Read packet ANC # n + 1. Subsequently, the ANC data packet ANC # n + 2 of the first field of the (M + 1) th frame is read from the shared memory 2095, and then the ANC data packet ANC # n + 3 of the second field of the (M + 1) th frame is read.
[0051]
Thereafter, the CPU 2094 executes normal read transfer processing.
[0052]
As described above, in the above embodiment, the data insertion unit 104 of the master station 10 has the ANC of the current field during the vertical blanking period in the field of the video signal to be transmitted to the remote station 20 via the broadcast relay network NW. The data is inserted and ANC data two fields before is inserted and transmitted to the remote station 20. Then, in the remote station 20, the video signal from the master station 10 is written in the frame memory 204 based on the write address synchronized with the video signal, and in the frame memory 204 based on the read address synchronized with the clock signal of the remote station 20. While the written video signal is read, the skip determination unit 208 compares the write address and the read address to determine the presence or absence of the frame skip. When a skip occurs, the reproduction processing unit 209 reproduces ANC data two fields before in the video signal.
[0053]
Therefore, even if a frame skip occurs at the remote station 20, the ANC data two fields before inserted in the vertical blanking period of the next frame is reproduced, so the ANC data before skipping and the ANC after skipping are reproduced. Data is clearly connected and can be reproduced without causing loss of ANC data. Furthermore, since the remote station 20 performs processing corresponding to the frame skip in the master station 10, the processing load on the remote station 20 can be reduced.
[0054]
Further, the playback processing unit 209 stores the ANC data of the current field and the ANC data of two fields before in the video signal read from the frame memory 204 in the shared memory 2093, and is notified of the occurrence of frame skip. At this time, the CPU 2094 only needs to read the ANC data two fields before on the shared memory 2093 and transfer it to the output control unit 2095. Thereafter, the CPU 2094 only needs to read the ANC data of the current field as usual. ANC data can be continued in the process. In addition, when the second frame skip occurs, it is only necessary to perform the same process, so that it is possible to always take a countermeasure for the occurrence of the frame skip.
[0055]
(Other embodiments)
The present invention is not limited to the above embodiments. In each of the embodiments described above, the case where the ANC data is delayed by exactly one frame and superimposed on the video signal has been described. However, the same effect can be obtained if at least one frame or more.
[0056]
Further, ANC data may be inserted in the horizontal blanking period in the frame of the video signal.
[0057]
In the above embodiment, an example of handling a video signal having a frame structure has been described. However, any frame structure can be flexibly handled.
[0058]
In the above embodiment, an example in which ANC data is superimposed on a field basis has been described. However, ANC data may be superimposed on a frame basis.
[0059]
Furthermore, in the above embodiment, an example in which a frame memory is used has been described, but a field memory or the like may be used.
[0060]
In addition, the system configuration, the configuration in the master station and the remote station, the type of accompanying data, the type of broadcast relay network, and the like can be variously modified and implemented without departing from the gist of the present invention.
[0061]
【The invention's effect】
As described above in detail, according to the present invention, a digital broadcast program relay transmission system capable of effectively dealing with the occurrence of frame skip occurring at the remote station side when performing network reception broadcast and its broadcast A station and a digital broadcast signal synchronization processing device can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of a digital broadcast program relay transmission system according to the present invention.
2 is a block diagram showing a configuration of a master station shown in FIG.
FIG. 3 is a block diagram showing a configuration of a remote station shown in FIG.
4 is a block diagram showing an example of a specific configuration of a reproduction processing unit shown in FIG.
FIG. 5 is a diagram showing the structure of a video signal on which ANC data is superimposed.
FIG. 6 is a diagram for explaining a processing operation in the system configuration of the embodiment.
[Explanation of symbols]
10 ... Master station,
20 ... remote station,
104: Data insertion part,
201: Input video synchronized playback unit,
202 ... writing section,
203... Write address generator,
204: Frame memory,
205 ... system synchronization generator,
206 ... Read address generator,
207 ... Read-out unit,
208... Skip determination unit,
209 ... Reproduction processing unit,
NW ... Broadcast broadcast network.

Claims (5)

A first broadcast station that sends a digital broadcast signal obtained by compressing and encoding a program information signal having a predetermined transmission block structure into the first broadcast service area based on the program organization time, and the first broadcast station and a relay line And a second broadcast service different from the first broadcast service area after receiving a program information signal sent from the first broadcast station via a relay line and applying signal processing. A digital broadcast program relay transmission system comprising a second broadcast station for transmitting as a digital broadcast signal in an area,
The first broadcasting station includes a first accompanying information corresponding to the transmission block including information related to the program in a predetermined blanking period in the transmission block of the program information signal, and a transmission block before the transmission block. An associated information transmitting means for inserting the corresponding second incidental information and transmitting it by the relay line;
The second broadcast station is
A memory for storing one transmission block of a program information signal arriving from the first broadcasting station via the relay line;
First clock reproduction means for inputting a program information signal coming from the first broadcasting station via the relay line and reproducing a clock signal synchronized with the program information signal;
A clock for generating a write address for specifying a storage area in the memory, and reproducing a program information signal arriving from the first broadcasting station via the relay line by the first clock reproducing means. Writing means for writing to the memory at a writing speed synchronized with a signal and generating the write address;
Second clock recovery means for recovering the clock signal of the own station;
Reading means for reading the program information signal written in the memory by the writing means at a reading speed synchronized with the clock signal reproduced by the second clock reproducing means, and generating a read address thereof;
A determination unit that compares the write address generated by the writing unit with the read address generated by the read unit to determine whether the write speed is equal to or higher than the read speed;
Reproduction processing means for selecting and reproducing one of the first incidental information and the second incidental information in the program information signal read from the memory based on the determination result by the determination means And a digital broadcast program relay transmission system. The reproduction processing means includes
Accompanying information storage means for storing the first and second accompanying information;
Input control means for managing the address of the accompanying information storage means, extracting the first and second accompanying information from the input program information signal, writing them to a predetermined address of the accompanying information storage means, and generating the address information; ,
An accompanying information reproduction control means for reading out and outputting one of the first and second accompanying information from the accompanying information storage means based on the address information from the input control means and the determination result by the determining means; The digital broadcast program relay transmission system according to claim 1, further comprising: A first broadcast station that sends a digital broadcast signal obtained by compressing and encoding a program information signal having a predetermined transmission block structure into the first broadcast service area based on the program organization time, and the first broadcast station and a relay line And a second broadcast service different from the first broadcast service area after receiving a program information signal sent from the first broadcast station via a relay line and applying signal processing. A broadcast station used as the first broadcast station in a digital broadcast program relay transmission system including a second broadcast station that transmits as a digital broadcast signal in an area;
First accompanying information corresponding to the transmission block including information related to the program during a predetermined blanking period in the transmission block of the program information signal and second accompanying information corresponding to the transmission block before the transmission block A broadcasting station characterized by comprising accompanying information transmission means for insertion and transmission through the relay line. A first broadcast station that sends a digital broadcast signal obtained by compressing and encoding a program information signal having a predetermined transmission block structure into the first broadcast service area based on the program organization time, and the first broadcast station and a relay line And a second broadcast service different from the first broadcast service area after receiving a program information signal sent from the first broadcast station via a relay line and applying signal processing. In a digital broadcast program relay transmission system comprising a second broadcast station for transmitting as a digital broadcast signal in an area, a digital broadcast signal synchronization processing device used in the second broadcast station,
A memory for storing one transmission block of a program information signal arriving from the first broadcasting station via the relay line;
First clock reproduction means for inputting a program information signal coming from the first broadcasting station via the relay line and reproducing a clock signal synchronized with the program information signal;
A clock for generating a write address for specifying a storage area in the memory, and reproducing a program information signal arriving from the first broadcasting station via the relay line by the first clock reproducing means. Writing means for writing to the memory at a writing speed synchronized with a signal and generating the write address;
Second clock recovery means for recovering the clock signal of the own station;
Reading means for reading the program information signal written in the memory by the writing means at a reading speed synchronized with the clock signal reproduced by the second clock reproducing means, and generating a read address thereof;
A determination unit that compares a write address generated by the writing unit with a read address generated by the read unit to determine whether the write speed is equal to or higher than the read speed;
Reproduction processing means for selecting and reproducing one of the first incidental information and the second incidental information in the program information signal read from the memory based on the determination result by the determination means And a digital broadcast signal synchronization processing device. The reproduction processing means includes
Accompanying information storage means for storing the first and second accompanying information;
Input control means for managing the address of the accompanying information storage means, extracting the first and second accompanying information from the input program information signal, writing them to a predetermined address of the accompanying information storage means, and generating the address information; ,
An accompanying information reproduction control means for reading out and outputting one of the first and second accompanying information from the accompanying information storage means based on the address information from the input control means and the determination result by the determining means; 5. The digital broadcast signal synchronization processing apparatus according to claim 4, further comprising:

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