JP4467827B2 - Active / preliminary switching device for digital broadcast program transmission system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a digital broadcast program transmission system having a duplex structure of active and standby, and more particularly to a switching control technique between active and standby.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in broadcast transmission facilities, it is common to have a working / spare duplex configuration for countermeasures and maintenance of equipment failures.
[0003]
Here, in the conventional analog broadcast program transmission system, the signal is not compressed, so that the shock is not conspicuous at the time of switching between active and standby, the frame is synchronized and switched at the frame position. It was enough to take measures against noise generated when switching contacts.
[0004]
However, in the digital broadcast program transmission system, a stream is formed by compressing broadcast data at the baseband system, and it is difficult to understand the break in the compressed stream. For this reason, in the digital broadcast program transmission system, when switching between active and standby, it is not possible to simply perform frame synchronization and switch at the frame position as in analog broadcasting.
[0005]
Also, in the digital broadcast program transmission system, the type and contents of the stream must be taken into account when switching between active and standby, which requires complicated processing such as discrimination processing, which is high as a switching device. Performance will be required.
[0006]
[Problems to be solved by the invention]
As described above, in a digital broadcast program transmission system, analog broadcasting technology cannot be applied as it is, and a switching device that smoothly switches between active and standby and requires high performance is required. It has become.
[0007]
An object of the present invention is to select a switching method in consideration of the type and contents of a digital broadcast signal to be handled, thereby enabling a digital broadcast that can be reliably switched between active and standby without causing disturbance in the transmission signal as much as possible. An object of the present invention is to provide a working / standby switching device for a program transmission system.
[0008]
[Means for Solving the Problems]
The present invention relates to a working / standby switching device for a digital broadcast program transmission system for selectively deriving a digital broadcast signal that has been compression-coded in a working system and a standby system and assigned to a transmission block according to a working / standby switching signal. The active and standby digital broadcast signals are stored for a predetermined number of blocks, and the active and standby digital broadcast signals are stored in the active and standby buffers. At the same time selectively deriving either one, there is a changeover switch for processing each block of the derived digital broadcast signal and at least one switching method for switching from the active system to the standby system or from the standby system to the active system Controls switching method information storage means for storing a plurality of switching methods composed of the indicated information and switching of the changeover switch. It is obtained by so and a replacement control unit.
[0009]
The switching control means, when a working / standby switching signal is input, a switching method selection function for selecting one switching method from a plurality of switching methods stored in the storage means according to a predetermined condition; To switch the switch from the active system to the standby system or from the standby system to the active system after determining the block that matches the switching position condition of the switching method indicated by the switching method selected in the active system buffer and the standby system buffer And a control function for performing control.
[0010]
According to the present invention, there is provided a switching method information storage means for storing information indicating a plurality of switching methods for switching from the active system to the standby system, so that, for example, the place of use, system change and digital broadcasting to be handled It is possible to select and set an optimal switching method according to a signal or the like and perform switching between active and standby without causing disturbance in the transmission signal as much as possible.
[0011]
The present invention also relates to a working / standby switching of a digital broadcasting program transmission system that selectively derives a digital broadcasting signal that is compression-coded in a working system and a standby system and is assigned to a transmission block according to a working / standby switching signal. In the apparatus, a working buffer and a standby buffer that store a predetermined number of blocks of each of the active and standby digital broadcast signals, and each of the active and standby digital broadcasts stored in the active buffer and the standby buffer. A selector switch that selectively derives one of the signals and simultaneously processes each block of the derived digital broadcast signal, and at least one switch for switching from the active system to the standby system or from the standby system to the active system Switching method information storage means for storing a plurality of switching methods composed of information indicating a method, and a type for measuring a predetermined time. When, in which as and a switching control means for controlling the switching of the changeover switch.
[0012]
Then, the switching control means includes a switching method selection function for selecting one switching method from the plurality of switching methods stored in the switching method information storage means, and one or more of the selected switching methods. A switching method selection function for selecting one switching method from among switching methods, a timer starting function for starting a timer to measure the application time of the switching method, and a predetermined time when a working / standby switching signal is input The switching method is selected by the switching method selection function according to the conditions, the switching method having the earliest switching order is selected from the selected switching methods by the switching method selection function, the timer is started by the timer starting function, and the timer is Determine whether there is a block that matches the switching position condition of the selected switching method in the active buffer and the standby buffer within the time of application of the selected switching method. If another switch is selected, control is performed to switch the changeover switch from the active system to the standby system or from the standby system to the active system. When it is determined that there is no switch, the switching method with the next highest switching order is selected by the switching method selection function. And a control function for executing the switching control.
[0013]
According to the present invention, the switching system information storage means for storing a plurality of switching systems composed of information indicating at least one switching method for switching from the active system to the standby system or from the standby system to the active system, At the time when the working / standby switching signal is input, one switching method is selected from a plurality of switching methods stored in the switching method information storage means according to a predetermined condition. The earliest switching method is selected, the timer is started, and this timer meets the switching position condition of the switching method selected in the active buffer and the standby buffer within the applicable time count of the selected switching method. If the presence or absence of a block is determined and it is determined that there is a block, control is performed to switch the changeover switch from the active system to the standby system, or from the standby system to the active system. If it is determined, then the selected fast switching method of switching order, will be performed switching control. In other words, if it is determined that there is no block that matches the switching method conditions in the active buffer and the standby buffer, the next switching method is automatically selected when the timer times out a predetermined time. Thus, the certainty of the switching control is guaranteed.
[0014]
For this reason, for example, it is possible not only to select and set the optimal switching method according to the place of use, system change, handled digital broadcasting signal, etc., and to switch between active and standby without causing disturbance in the transmission signal as much as possible, It can be done reliably.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0016]
(First embodiment)
FIG. 1 is a block diagram showing a first embodiment of a digital broadcast program transmission system according to the present invention. In FIG. 1, 11 is an active transmission device, and 12 is a standby transmission device.
[0017]
The active transmission device 11 includes a switcher (SW) 111 that selectively outputs program material data, an automatic program transmission control device (APC) 112 that switches and controls the switcher 111 based on program organization data, and the automatic program transmission. An encoder (ENC) 113 that converts the program material data output from the switcher 111 based on the switching control of the control device 112 into variable-length compression encoding based on the MPEG2 encoding method and converts it into an MPEG2 transport stream packet, and the encoder 113 Multiplexer (MUX) 114 for packet-multiplexing the output packet and various control data, and encoding multiplexing control device (EMC) 115 for controlling encoder 113 and multiplexer 114 based on control information from automatic program transmission control device 112. Is provided.
[0018]
The standby transmission device 12 has exactly the same configuration as that of the active system, and includes a switcher (SW) 121, an automatic program transmission control device (APC) 122, an encoder (ENC) 123, a multiplexer (MUX) 124, and an encoding multiplex control device ( EMC) 125.
[0019]
The active transmission device 11 and the standby transmission device 12 perform synchronous operation between the encoders 113 and 123, and MPEG2 transport stream packets output from the respective transmission devices 11 and 12 are sent to the active / spare switching device 13. Supplied.
[0020]
The working / standby switching device 13 includes buffers 131 and 132, a switch (SW) 133, a switching method storage unit 134, a timer 135, and a switching control unit 136.
[0021]
The buffers 131 and 132 once hold a predetermined number of packet sequences from the active transmission device 11 and the standby transmission device 12.
[0022]
The change-over switch 133 includes an output buffer selection function 1331 and a packet processing function 1332, and selectively sends out a packet in each of the buffers 131 and 132 to generate a transmission signal.
[0023]
The switching method storage unit 134 stores one or more switching methods composed of a plurality of switching methods associated with the switching order as shown in FIG. In the example of FIG. 2, one switching method is stored.
[0024]
The timer 135 measures a predetermined time.
[0025]
The switching control unit 136 includes a switching method selection function 1361, a switching method selection function 1362, a timer activation function 1363, and a switch switching control function 1364. Among these, the switching method selection function 1361 selects one switching method from one or a plurality of switching methods stored in the switching method storage unit 134.
[0026]
The switching method selection function 1362 selects one switching method from one or a plurality of switching methods included in the switching method selected by the switching method selection function 1361.
[0027]
The timer activation function 1363 activates the timer 135 in order to measure the application time of the switching method.
[0028]
The switch switching control function 1364 is switched by the switching system selection function 1361 based on the condition that it is an MPEG2 transport stream packet from the synchronized encoders 113 and 123 at the time when the working / standby switching signal is input. Select the switching method stored in. Then, the switching method having the earliest switching order is selected from the selected switching methods by the switching method selection function 1362, the timer 135 is started by the timer starting function 1363, and the timer 135 is within the application time count of the selected switching method. Then, it is determined whether or not there is a packet suitable for the switching position condition of the switching method selected in each of the buffers 131 and 132. Here, when it is determined that there is a switch, the switch 133 is controlled to switch from the active system to the standby system or from the standby system to the active system. Select the switching method with the highest priority and execute the switching control.
[0029]
The processing operation of the above configuration will be described below.
[0030]
In the active / preliminary switching device 13, the MPEG2 transstream packets from the active transmission device 11 are input to the buffer 131, and the MPEG2 transstream packets from the standby transmission device 12 are input to the buffer 132. Sequentially hold the packets.
[0031]
In this state, when a working / standby switching signal is input, the switching method storage unit 134 is based on the condition that the switch switching control function 1364 of the switching control unit 136 is an MPEG2 transstream packet from the synchronized encoders 113 and 123. One switching method is selected from the above, and control processing as shown in FIG. 3 is started based on a plurality of switching methods constituting the switching method.
[0032]
When this control process is started, the switch switching control function 1364 performs the initial setting (i = 1) of the switching order (step ST1), and is stored in the buffers 131 and 132 based on the switching method corresponding to the switching order 1. A packet that matches the conditions of the switching position is found from the packet (step ST2), and the timer 135 is started (step ST3).
[0033]
While the timer 135 is activated, the switch switching control function 1364 compares the contents of the packets held in the buffers 131 and 132, and determines whether or not there is a packet that matches the conditions of the switching positions of audio, video, and data. (Step ST4). Here, if there is a matched packet, the switch switching control function 1364 controls the switching switch 133 to switch the switching target data at the switching position (step ST5). The changeover switch 133 receives the timing signal from the switch changeover control function 1364, and uses the output buffer selection function 1331 and the packet processing function 1332 to execute the changeover of the switch target data at the changeover position by the method indicated by the changeover method.
[0034]
On the other hand, when a packet that matches the switching position condition is not found, the switch switching control function 1364 repeatedly executes the processing of step ST4 and step ST6 if the timer 135 is measuring time. The switch switching control function 1364 executes switching control based on the switching method corresponding to the next switching order 2 at the time when the predetermined elapsed time is measured (step ST7), and thereafter the switching process is executed. The processes of step ST4 and step ST6 are repeated. The switching method is as follows.
[0035]
(1) When the encoder has a switching point, switching is performed at the packet boundary with the switching point.
(2) Switching is performed at the boundary between the units to be compressed and encoded so that the decoding time information is continuous.
(3) Pseudoblocks (silence for video, freeze, silence for audio, etc.) are inserted so that the decoding time information is continuous, and switching is performed at the boundary between units to be compression-coded.
(4) Switching is performed at the boundary between units to be compressed and encoded regardless of the continuity of the decoding time information.
(5) Switch reliably at the transport stream packet boundary.
[0036]
As described above, in the first embodiment, the switching method storage unit 134 that stores a switching method including a plurality of switching methods for switching from the active system to the standby system or from the standby system to the active system is provided. When the current / preliminary switching signal is input, the switch switching control function 1364 of the switching control unit 136 stores the switching method based on the condition that the MPEG2 transport stream packet from the synchronized encoders 113 and 123 is received. One switching method is selected from the unit 134, and the switching method with the earliest switching order is selected from a plurality of switching methods indicated in the switching method, and at the same time, the timer 135 is started, and within a predetermined time from the starting time If no packet that matches the switching position condition of the switching method is found from the buffers 131 and 132, Select the exchange technique to perform the switching control.
[0037]
Accordingly, when a packet that matches the switching position of the switching method is not found from the buffers 131 and 132, the switching method of the next switching order is selected and the switching control is executed. It is possible not only to select and set an optimal switching method according to the broadcast signal and the like, but to perform the switching between the active and the standby without causing disturbance in the transmission signal as much as possible, and also to be able to perform it reliably.
[0038]
(Second Embodiment)
FIG. 4 is a block diagram showing a second embodiment of the digital broadcast program transmission system according to the present invention. In FIG. 4, the same parts as those in FIG.
[0039]
In other words, in the second embodiment, the output of the active encoder 113 and the output of the standby encoder 123 are input to the switch 21, and the inputs are input to the active multiplexer 114 and the standby multiplexer 124. It can be selectively derived.
[0040]
In addition, the switching method storage unit 134 of the active / standby switching device 13 stores a switching method including a plurality of switching methods associated with the switching order as shown in FIG.
[0041]
Since the processing operation is the same as the processing operation and the switching method selection condition and switching method shown in the first embodiment, the switching method selection condition and the switching method are described below.
[0042]
The switching method selection condition is that one of the encoders 113 and 123 is a digital broadcast signal divided into two, and the switching method is shown below.
[0043]
(1) Switch at the packet boundary where the continuity counter is equal.
(2) Switching is performed at the boundary between the units to be compressed and encoded so that the decoding time information is continuous.
(3) Pseudoblocks (silence for video, freeze, silence for audio, etc.) are inserted so that the decoding time information is continuous, and switching is performed at the boundary between units to be compression-coded.
(4) Switching is performed at the boundary between units to be compressed and encoded regardless of the continuity of the decoding time information.
(5) Switch reliably at the transport stream packet boundary.
[0044]
With such a second embodiment, the same effects as those of the first embodiment can be obtained. However, when the encoder output of a plurality of operators is input to the multiplexer 124, the encoder 113 of a certain operator is used. , 123 is normal, the switching of the working / standby switching device 13 does not affect the output stream of the encoder, and the switch 21 due to which one of the encoders 113, 123 of a certain operator has failed. This has the effect of not affecting the streams of other operators.
[0045]
(Third embodiment)
FIG. 6 is a block diagram showing a third embodiment of the digital broadcast program transmission system according to the present invention. In FIG. 6, the same parts as those in FIG.
[0046]
In other words, the working sending apparatus 11 and the standby sending apparatus 12 in the third embodiment operate completely independently, and the MPEG2 transstream packets output from the working sending apparatus 11 and the standby sending apparatus 12 are used. -It is supplied to the standby switching device 13.
[0047]
Further, the switching method storage unit 134 of the active / standby switching device 13 stores a switching method including a plurality of switching methods associated with the switching order as shown in FIG.
[0048]
Since the processing operation is the same as the processing operation and the switching method selection condition and switching method shown in the first embodiment, the switching method selection condition and the switching method are described below.
[0049]
The switching method selection condition is that the encoder 113 and the encoder 123 operate independently, and this means that there is not much consideration in switching. The switching method is shown below.
[0050]
(1) Switch reliably at transport stream packet boundaries.
[0051]
In such a third embodiment, the same effect as in the first embodiment can be obtained, but in the case of a stream that does not particularly need to consider switching, fine switching control is not required, The burden of processing can be reduced.
[0052]
(Other embodiments)
The present invention is not limited to the above embodiments. That is, in each of the above-described embodiments, an example in which time is used as a switching condition of information indicating a switching method has been described. However, in addition to time, a place of use, a change in system, a digital broadcast signal to be handled, and the like can be used. .
[0053]
In addition to the MPEG2 transport stream, it is also possible to handle digital broadcast signals that have been compression-encoded in the active system and the standby system and assigned to the transmission block.
[0054]
In addition, the system configuration, the configuration of the working / standby switching device, the storage content of the switching method storage unit, and the like can be variously modified and implemented without departing from the gist of the present invention.
[0055]
【The invention's effect】
As described above in detail, according to the present invention, by selecting the switching method in consideration of the type and contents of the digital broadcasting signal to be handled, switching between the working and standby can be performed without causing disturbance in the transmission signal as much as possible. In addition, it is possible to provide a working / standby switching device for a digital broadcast program transmission system that can guarantee certainty of switching by providing a plurality of switching methods in the switching method and limiting the application time.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a first embodiment of a digital broadcast program transmission system according to the present invention.
FIG. 2 is a diagram showing an example of storage contents of a switching method storage unit shown in FIG.
FIG. 3 is a flowchart for explaining a control processing procedure of a switching control unit shown in FIG. 1;
FIG. 4 is a block diagram showing a second embodiment of the digital broadcast program transmission system according to the present invention.
FIG. 5 is a diagram showing an example of storage contents of a switching method storage unit shown in FIG. 4;
FIG. 6 is a block diagram showing a third embodiment of the digital broadcast program transmission system according to the present invention.
7 is a diagram showing an example of storage contents of a switching method storage unit shown in FIG.
[Explanation of symbols]
11 ... active transmission device,
12 ... Preliminary sending device,
111, 121 ... switcher (SW),
112, 122 ... Automatic program transmission control device (APC),
113, 123 ... Encoder (ENC),
114, 124 ... Multiplexer (MUX),
115, 125 ... Encoding Multiple Controller (EMC),
13: Active / standby switching device,
131, 132 ... buffer,
133 ... changeover switch (SW),
134 ... switching method storage unit,
135 ... Timer,
136... Switching control unit,
1331: Output buffer selection function,
1332 ... Packet processing function,
1361 ... switching method selection function,
1362 ... switching method selection function,
1363: Timer start function,
1364: Switch switching control function.

Claims (5)

In a working / standby switching device of a digital broadcast program transmission system that selectively derives a digital broadcast signal that is compression-coded in a working system and a standby system and assigned to a transmission block according to a working / standby switching signal,
A working buffer and a standby buffer for storing a predetermined number of blocks of each of the working and standby digital broadcast signals;
At the same time selectively deriving one of the active and standby digital broadcast signals stored in the active buffer and the standby buffer, and simultaneously switching control of switching target data among the derived digital broadcast signals A change-over switch for adding processing related to
A switching method information storage means for storing a plurality of switching methods composed of information indicating at least one switching method for switching from the active system to the standby system or from the standby system to the active system;
Switching control means for controlling switching of the changeover switch,
The switching control means includes
A switching method selection function for selecting one switching method from a plurality of switching methods stored in the storage means according to a predetermined condition when the working / standby switching signal is input;
A block that matches the switching position condition of the switching method indicated by the selected switching method in the working buffer and the standby buffer is determined, and based on the determination result, the switch is switched from the working system to the standby system. Or a working / standby switching device for a digital broadcast program sending system, characterized by having a control function for performing control for switching from a standby system to a working system. In a working / standby switching device of a digital broadcast program transmission system that selectively derives a digital broadcast signal that is compression-coded in a working system and a standby system and assigned to a transmission block according to a working / standby switching signal,
A working buffer and a standby buffer for storing a predetermined number of blocks of each of the working and standby digital broadcast signals;
At the same time selectively deriving one of the active and standby digital broadcast signals stored in the active buffer and the standby buffer, and simultaneously switching control of switching target data among the derived digital broadcast signals A change-over switch for adding processing related to
A switching method information storage means for storing a plurality of switching methods composed of information indicating at least one switching method for switching from the active system to the standby system or from the standby system to the active system;
A timer for measuring a predetermined time;
Switching control means for controlling switching of the changeover switch,
The switching control means includes
A switching method selection function for selecting one switching method from a plurality of switching methods stored in the switching method information storage means;
A switching method selection function for selecting one switching method from one or a plurality of switching methods included in the selected switching method;
A timer start function for starting the timer to measure the application time of the switching method;
When the current / preliminary switching signal is input, a switching method is selected by the switching method selection function according to a predetermined condition, and the switching method having the earliest switching order is selected from the selected switching method by the switching method selection function. Select a method, start a timer with the timer start function, and within the application time count of the switching method selected by the timer, the switching position of the selected switching method in the active buffer and the standby buffer When the presence or absence of a block that meets the conditions is determined, and it is determined that there is, the control for switching the changeover switch from the active system to the standby system or from the standby system to the active system is performed, and when it is determined that there is no A digital broadcast program transmission system having a control function for selecting a switching method with the next highest switching order by a switching method selection function and executing switching control Working-spare switching device. When the active and standby digital broadcast signals are compressed and encoded in synchronization with each other, and the switching position is indicated on the block,
The switching method information storage means includes a method of switching at least at a block boundary where the switching position is indicated, a method of switching at a boundary of units that are compression-encoded so that decoding time information is continuous, and pseudo so that decoding time information is continuous. A switching method that consists of a method of switching at the boundary between the units to be compressed and encoded by inserting a block, a method of switching at the boundary of the unit to be compressed and encoded regardless of the continuity of the decoding time information, and a method of switching at the block boundary The working / preliminary switching device for a digital broadcast program transmission system according to claim 1 or 2, wherein the device is stored. When each of the active and standby digital broadcasting signals is obtained by distributing the same signal twice, and each block of the digital broadcasting signal adds numerical information different from the preceding and following blocks,
The switching method information storage means includes at least a method of switching using the numerical information, a method of switching at a unit boundary to be compressed and encoded so that decoding time information is continuous, and a pseudo block so that decoding time information is continuous. Stores a switching method composed of a method of switching at the boundary between units to be inserted and compressed and encoded, a method of switching at a boundary between units to be compressed and encoded regardless of the continuity of decoding time information, and a method of switching at a block boundary. The working / standby switching device for a digital broadcast program transmission system according to claim 1 or 2. When each of the working and standby digital broadcasting signals is compressed and encoded independently of each other,
The switching method information storage means stores at least a switching method composed of a method of switching at a boundary between units to be compressed and encoded regardless of continuity of decoding time information and a method of switching at a block boundary. Item 3. A working / standby switching device for a digital broadcast program sending system according to item 1 or 2.

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