JP4327755B2 - Digital broadcast signal switching transmission device - Google Patents

Description

  The present invention relates to a digital broadcast signal switching transmission device that selectively switches and transmits a plurality of systems of digital broadcast signals.

  The broadcast transmission facility has a working / spare duplex configuration for equipment failure countermeasures and maintenance. In other words, when the currently used broadcast signal is deteriorated for some reason and cannot be used for broadcasting, the system immediately switches to the standby system.

  By the way, in digital broadcasting, if the delay and phase of the signal are slightly deviated between the systems at the time of system switching, discontinuity occurs in the signal before and after switching, and the signal quality of the switching output deteriorates. End up.

Therefore, conventionally, a method has been proposed in which, when the system is switched, the signal format of each system is analyzed to determine the switchable position of the active signal, and the switchable position is switched to the standby signal at this switchable position (for example, Patent Document 1).
JP 2000-341335 A.

  However, in the above method, switching control is performed by a plurality of computers for each system, and there is a difference in processing time between systems due to differences in the processing speed of each computer, the status of time-sharing processing, and background processing. Will occur.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a digital broadcast signal switching transmission device that can switch the switching timing between the respective systems when switching the systems of digital broadcast signals.

In order to achieve the above object, the present invention is configured as follows.
A digital broadcast signal switching transmission device for selectively switching and transmitting a plurality of systems of digital broadcast signals according to a switching instruction signal, wherein a synchronizing signal generating means for generating a vertical synchronizing signal of a video signal and a switching instruction signal are input A switching control signal generating means for generating and outputting a switching control signal synchronized with the vertical synchronization signal from the switching instruction signal, and a digital broadcast signal of a system as a switching source based on the switching control signal and the vertical synchronization signal Adjusting means for synchronizing the digital broadcasting signal of the system to be switched to and a switching means for taking in the digital broadcasting signal of each system after adjustment by this adjusting means and switching the transmission system It is.

  According to this configuration, when a switching instruction signal is input, a switching control signal synchronized with the vertical synchronization signal of the video signal is generated from the switching instruction signal, and switching is performed based on the switching control signal and the vertical synchronization signal. Switching is performed after synchronizing the digital broadcast signal of the original system and the digital broadcast signal of the system of the switching destination. Therefore, it becomes possible to synchronize the digital broadcast signals between the systems by using the vertical synchronization signal of the video signal, thereby controlling the switching timing at the time of system switching.

  When the digital broadcast signal conforms to MPEG2 Systems, the adjusting means is provided in each system, and an encoder that encodes the baseband video signal into TS (Transport Stream) and each system, and the switching control signal is provided. The change point from the first signal level to the second signal level of the received vertical synchronization signal is used as a reference point, and switching is performed at the change point from the first signal level to the second signal level after a predetermined time has elapsed from this reference point. An encoder control unit that controls the encoder so as to synchronize the original TS and the switching destination TS is provided. Further, when the switching control signal generating means and the encoders and encoder control units of each system are connected by a network, the switching control signal generating means is configured to perform vertical synchronization after input when a switching instruction signal is input. The change point from the first signal level to the second signal level of the signal is used as a reference point, and the network is connected to the encoder control unit of each system at the change point from the first signal level to the second signal level next to the reference point. The switching control signal is transmitted through the network.

  According to this configuration, even if the switching control signal arrives at a different timing for each encoder control unit between the systems due to network communication traffic or the like, the vertical direction after the switching control signal is received by each encoder control unit With respect to the change point of the synchronization signal from the first signal level to the second signal level as a reference, the change point from the first signal level to the second signal level after a predetermined time has elapsed, that is, the timing including the internal processing time Can be synchronized.

  As described above in detail, according to the present invention, it is possible to provide a digital broadcast signal switching transmission device capable of adjusting the switching timing between the systems when switching the systems of the digital broadcast signals.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of an embodiment of a digital broadcast signal switching transmission device according to the present invention. In FIG. 1, baseband video signals of HDTV (High Definition TV) system (1125 line system) and SDTV (Standard Definition TV) system (525 line system) are supplied to system 1 input and system 2 input, respectively.

  A 1-system input HDTV baseband video signal is converted into an MPEG2 TS (Transport Stream) by an HD encoder (HDENC) 11. The SDTV baseband video signal of system 1 input is converted into MPEG2 TS by the SD encoder (SDENC) 12. These TSs are multiplexed with other TSs by a multiplexer (MUX) 13 and supplied to the TS splicer 14.

  Similarly, a 2-system input HDTV baseband video signal is converted into an MPEG2 TS by the HD encoder 15. Further, the SDTV baseband video signal of 2-system input is converted into MPEG2 TS by the SD encoder 16. These TSs are multiplexed with other TSs by the multiplexer 17 and supplied to the TS splicer 14.

  The TS splicer 14 switches and outputs the TS of either system 1 or system 2 based on the splicing point flag inserted in the TS.

  The HD encoder 11 and the SD encoder 12 are connected to an encoding multiplex control device (EMC) 19 via a LAN (Local Area Network) 18-3. The HD encoder 15 and the SD encoder 16 are connected to an encoding multiplex control device (EMC) 20 via a LAN 18-4. Further, the encoding multiplex control device 19 is connected to a switching instruction generator (SYSCHG NODE) 21 via a LAN 18-1, and the encoding multiplex control device 20 is connected to the switching instruction generator 21 via a LAN 18-2. .

  The encoding multiplex control devices 19 and 20 and the switching instruction generator 21 operate based on a BB (Black Burst) signal which is a video vertical synchronization signal generated from the BB signal distributor 22.

  The BB signal distributor 22 generates a BB signal composed of a synchronization signal and a color burst signal and supplies the BB signal to the encoding multiplex control devices 19 and 20 and the switching instruction generator 21.

  When a switching instruction signal for a system is given, the switching instruction generator 21 generates a SYSHG control signal synchronized with the BB signal from the switching instruction signal, and encodes the SYSHG control signal via the LANs 18-1 and 18-2. The data is sent to the multiplex control devices 19 and 20.

  The encoding multiplex control device 19 controls the HD encoder 11 and the SD encoder 12. When receiving the SYSSCHG control signal, the encoding multiplex control device 19 is based on the SYSSCHG control signal and the BB signal. The TS obtained by the encoder 12 is synchronized with the TS obtained by the HD encoder 15 and the SD encoder 16, and then a splicing point flag is inserted into the TS.

  The encoding multiplex control device 20 controls the HD encoder 15 and the SD encoder 16, and when receiving the SYSSCHG control signal, the encoding multiplex control device 20 uses the HD encoder 15 and the SD encoder based on the SYSSCHG control signal and the BB signal. The TS obtained by the encoder 16 is synchronized with the TS obtained by the HD encoder 11 and the SD encoder 12, and then a splicing point flag is inserted into the TS.

Next, the operation in the above configuration will be described with reference to FIG.
In the terrestrial digital broadcast coding and multiplexing system, each system is constructed by an independent LAN system. For this reason, in an encoding and multiplexing system, it is necessary to switch the system in accordance with the timing, and it is necessary to match the switching timing to each system.

  Therefore, as shown in FIG. 2, when the switching instruction signal (CHG interrupt) is given by the user's manual operation, the switching instruction generator 21 changes the L level from the H (high) level of the BB signal after receiving the switching instruction signal. The change point (falling) to the (low) level is used as a reference point, and it is recognized that the switching instruction has arrived at this reference point, and the SYSSCHG control signal is sent to the LAN 18-1, 18- at the next falling timing from the reference point. 2 to the encoding multiplex control devices 19 and 20.

  When the SYSSCHG control signal arrives, the encoding and multiplexing control device 19 uses the falling edge of the BB signal after reception of the SYSCHG control signal as a reference point, and recognizes that the SYSCHG control signal has arrived at this reference point. The HD encoder 11 and the SD encoder 12 are controlled via the LAN 18-3 at the falling timing of the BB signal after a certain processing time has elapsed from this reference point, and the 1-system TS is converted to the 2-system TS. Synchronize with TS. At this time, a splicing point flag is inserted into the output TS of each of the HD encoder 11 and the SD encoder 12.

  On the other hand, when the SYSSCHG control signal arrives, the encoding and multiplexing control apparatus 20 uses the falling edge of the BB signal after receiving the SYSCHG control signal as a reference point, and recognizes that the SYSCHG control signal has arrived at this reference point. The HD encoder 15 and the SD encoder 16 are controlled via the LAN 18-4 at the falling timing of the BB signal after a lapse of a certain processing time from the reference point, so that the 2 system TS is converted to the 1 system TS. Synchronize with TS.

  The TS splicer 14 switches to the second system TS based on the splicing point flag inserted in the first system TS. As a result, the TS before the switching and the TS after the switching are clearly connected, and the TS is transmitted without causing any disturbance in the information.

  As described above, in the above embodiment, when a switching instruction signal is input to the switching instruction generator 21, the switching instruction generator 21 generates a SYSCHG control signal synchronized with the BB signal of the video signal from the switching instruction signal. And sent to the encoding multiplex control devices 19 and 20 via the LANs 18-1 and 18-2. The encoding multiplex control devices 19 and 20 use the HD encoders 11 and 15 on the basis of the SYSHGG control signal and the BB signal. In addition, the TS encoders 12 and 16 are controlled to synchronize the 1-system TS and the 2-system TS, and these TS are switched by the TS splicer 14.

  That is, even if a SYSSCHG control signal arrives with a timing lag with respect to each of the encoding multiplex control devices 19 and 20 between the systems due to communication traffic of the LANs 18-1 and 18-2, the respective encoding multiplex control devices 19. , 20 synchronizes TS between the 1st and 2nd systems at the falling edge after a certain processing time has elapsed with reference to the falling edge of the BB signal after receiving the SYSCHG control signal, that is, including the internal processing time. be able to.

  Therefore, it becomes possible to synchronize the TS between the first and second systems by using the vertical synchronization signal of the video signal, thereby controlling the switching timing of the TS splicer 14 at the time of system switching.

  In the above embodiment, the BB signal distributor 22 can generate the BB signal by a simple procedure by using the synchronization signal and the color burst signal.

  Further, in the above embodiment, the encoding multiplex control devices 19 and 20 control the HD encoders 11 and 15 and the SD encoders 12 and 16 in parallel to synchronize between the first and second systems. Therefore, even when HD broadcasting / SD broadcasting is performed in a mixed manner, the system switching of the TS splicer 14 can be performed smoothly.

  In the above embodiment, the BB signal is used as the vertical synchronization signal of the video signal. However, a vertical synchronization signal other than the BB signal may be used.

  Moreover, although the said embodiment demonstrated the case of two input systems, even when it has many more systems, it can implement similarly.

  Further, in the above embodiment, the encoding multiplex control device 19 and the switching instruction generator 21 are connected by the LAN 18-1, and the encoding multiplex control device 20 and the switching instruction generator 21 are connected by the LAN 18-2. The HD encoder 11 and the SD encoder 12 and the encoding multiplexing control device 19 are connected by a LAN 18-3, and the HD encoder 15 and the SD encoder 16 and the encoding multiplexing control device 20 are connected. An example of connection via the LAN 18-4 has been described. However, the present invention is not limited to this, and the present invention can be similarly implemented even with a configuration connected to a network other than the LANs 18-1 to 18-4.

  In addition, the present invention is not limited to the above embodiment, and can be implemented with various modifications.

The block diagram which shows the structure of one Embodiment of the digital broadcast signal switching transmission apparatus which concerns on this invention. The figure shown in order to demonstrate the processing operation in the same embodiment.

Explanation of symbols

  11, 15 ... HD encoder (HDENC), 12, 16 ... SD encoder (SDENC), 13, 17 ... Multiplexer (MUX), 14 ... TS splicer, 18-1 to 18-4 ... LAN (Local Area) Network), 19, 20... Encoding multiplex control device (EMC), 21... Switching instruction generator (SYSCHG NODE), 22.

Claims (6)

A digital broadcast signal switching transmission device for selectively switching and transmitting a plurality of digital broadcast signals according to a switching instruction signal,
Synchronization signal generating means for generating a vertical synchronization signal of the video signal;
A switching control signal generating means for generating and outputting a switching control signal synchronized with the vertical synchronization signal from the switching instruction signal when the switching instruction signal is input;
Based on the switching control signal and the vertical synchronization signal, adjusting means for synchronizing the digital broadcast signal of the system serving as the switching source and the digital broadcast signal of the system serving as the switching destination;
A digital broadcast signal switching transmission device comprising switching means for taking in the digital broadcast signal of each system after adjustment by the adjustment means and switching the transmission system. The adjusting means inserts a switching point flag in the digital broadcast signal of the switching source system after adjustment,
2. The digital broadcast signal switching transmission according to claim 1, wherein the switching means switches to a digital broadcast signal of a switching destination system based on a switching point flag inserted in the digital broadcasting signal of the switching source system. apparatus. When the digital broadcast signal is compliant with MPEG2 Systems,
The adjusting means includes
An encoder that is provided in each system and encodes a baseband video signal into a TS (Transport Stream);
A first signal provided in each system and having a change point from the first signal level to the second signal level of the vertical synchronization signal after receiving the switching control signal as a reference point, and a first signal after a predetermined time has elapsed from the reference point 2. The digital broadcasting according to claim 1, further comprising: an encoder control unit that controls the encoder so as to synchronize a switching source TS and a switching destination TS at a change point from the level to the second signal level. Signal switching transmission device. When the switching control signal generating means and the encoder and encoder control unit of each system are connected by a network,
When the switching instruction signal is input, the switching control signal generating means uses a change point from the first signal level to the second signal level of the vertical synchronization signal after the input as a reference point, and next to the reference point. 4. The digital broadcast signal switching transmission device according to claim 3, wherein the switching control signal is transmitted via the network to an encoder control unit of each system at a change point from the first signal level to the second signal level. . The digital encoder according to claim 3, wherein the encoder control unit controls each of the 1125-line system encoder and the 525-line system encoder to synchronize the switching source TS and the switching destination TS. Broadcast signal switching transmission device. 2. The digital broadcast signal switching transmission device according to claim 1, wherein the synchronization signal generating means generates a signal composed of a synchronization signal and a color burst signal as the vertical synchronization signal.

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