CN213244180U - Control device for video emergency switching - Google Patents

Abstract

The utility model relates to a radio and television technical field provides a controlling means for emergent switching of video, and it includes: the control panel, the input end of the control panel is connected with broadcasting equipment, the broadcasting equipment provides corresponding state parameters according to the channel selected by the control panel, and the control panel responds to the abnormal state parameters and sends out control instructions; and the control panel server is in communication connection with the control panel and is used for acquiring the state parameters of the broadcasting equipment, providing the state parameters to the control panel, setting the on-off of the main video server signal line and the standby video server signal line according to the control instruction, and switching the current video broadcasting channel line to one of the alternative channel lines or switching the current broadcasting equipment to the alternative broadcasting equipment. Therefore, the working efficiency and the reliability of video emergency switching can be improved.

Description

Control device for video emergency switching

Technical Field

The utility model relates to a broadcast television technical field, concretely relates to a controlling means for emergent switching of video.

Background

With the rapid development of the broadcast television industry, the requirements on the performance of the safe broadcasting equipment, such as broadcasting quality, stability, safety and the like, are higher and higher. However, a television broadcasting system is large and complex, broadcasting faults occur inevitably due to various reasons, and when the broadcasting faults occur, technicians often find the broadcasting faults in time due to the reasons of multiple program channels, heavy tasks, fatigue, inattention, lack of technical means and the like, and the emergency treatment speed is low, so that broadcasting accidents are caused. At present, the method for dealing with the broadcasting failure to stop broadcasting mainly depends on manual management and alarm means. However, whether the manual management or the alarm means is enhanced, due to differences of energy, responsibility, technical capability and the like of all people, the requirements of timely finding and fast emergency treatment when broadcasting faults occur are difficult to meet. In order to achieve the aim of 'uninterrupted', the system design needs to pay attention to the backup of equipment and the configuration of an emergency switching system, and the emergency switching of the backup equipment is the only way for ensuring uninterrupted broadcasting.

The emergency switching aims at switching from the fault equipment to the normal equipment within the shortest time to ensure the continuous broadcasting of programs and avoiding the influence on users as much as possible in the switching process. The commonly used means is to insert other programs, the insertion time can be neither too long nor too short to interrupt the playing, and the control of the insertion time is very important.

The existing video emergency switching device mainly comprises an automatic switching device and a manual switching device. The manual video switcher is the simplest video switcher, and the device is provided with a plurality of keys for outputting and displaying a selected camera image to a single monitor. The manual switching is economical and reliable, and 4-16 paths of video input can be switched to one monitor for output; the disadvantage is that vertical flipping and scrolling on the monitor occurs when the manual switch is made, and does not disappear until the monitor determines that there is a vertical synchronization pulse input to the camera.

The automatic video switcher is an intelligent switcher, but the automatic switching is not required when ALL the playing problems are met, so that the automatic switching and the manual switching are limited, and IN a television broadcasting system, based on an integrated (ALL-IN-ONE) broadcasting framework, when a video server has broadcasting signal abnormity and server hardware faults or ONE or more conditions of emergency signal switching and caption emergency processing are required, the conventional equipment cannot realize quick, efficient and convenient emergency switching.

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problem, the utility model provides a controlling means for emergent switching of video can improve the reliability when work efficiency and the emergent switching of video.

According to the utility model provides a pair of a controlling means for emergent switching of video, wherein, include:

the control panel, the input end of the control panel is connected with broadcasting equipment, the broadcasting equipment provides corresponding state parameters according to the currently selected channel of the control panel, and the control panel responds to the abnormal state parameters and sends out control instructions;

and the control panel server is in communication connection with the control panel and is used for acquiring the state parameters of the broadcasting equipment, providing the state parameters to the control panel, setting the on-off of the main video server signal lines according to the control instruction, and switching the current video playing channel line to one of the alternative channel lines or switching the current broadcasting equipment to the alternative broadcasting equipment.

Preferably, the aforementioned state parameters include: the signal connection state of the current broadcasting equipment, the current channel information, the broadcasting video information, the signal state and the display state of the caption layer corresponding to the current channel,

the abnormal state parameters are: and at least one of the signal connection state, the current channel information, the playing video information, and the signal state and the display state of the caption layer corresponding to the current channel of the current playing equipment is abnormal.

Preferably, the aforementioned control instructions include: a channel lamp instruction, an external input signal instruction, a graphic and text path number instruction and a heartbeat connection instruction.

Preferably, the control panel comprises a switching module, the switching module comprising:

a plurality of channel selection switches arranged in an array;

the system comprises a plurality of input selection switches arranged in an array, a plurality of video signal processing units and a plurality of video signal processing units, wherein any channel selected by the corresponding switch can be correspondingly selected to input one of a plurality of external input signals, and the plurality of external input signals are synchronous live video signals or called video signals of playing materials;

the image-text selection switches are arranged in an array, and at least one image-text path number can be correspondingly selected corresponding to any channel selected by the switches;

and the locking switch is used for providing locking or unlocking of the selection switch on the control panel.

Preferably, the control panel further comprises:

the power supply module is provided with at least two power supply interfaces, the at least two power supply interfaces are respectively and correspondingly connected with independent power supplies, and the power supply module is used for selecting one of the at least two power supplies to be conducted for power supply;

and the communication interface module is provided with at least two serial communication interfaces which are respectively connected with the broadcasting equipment and the control panel server and are used for receiving the state parameters and sending the control instructions.

Preferably, the control panel further comprises a switching display module connected to the switching module, and the switching display module comprises:

a power indicator for indicating a selected power source;

and the switch state lamps are controlled by the switching module, correspond to the selection switches and the locking switches one by one and are used for indicating the operation states of the corresponding switches.

Preferably, any one of the selection switch and the locking switch is a key switch, and the switch status light is embedded in the corresponding key switch.

Preferably, any one of the selection switch and the locking switch is a toggle switch, and the switch-state lamp is located near the corresponding toggle switch.

Preferably, the control panel includes a touch display screen, and the touch display screen is used for displaying the state parameters and the touch operation of the selection switch and/or the locking switch.

Preferably, the control panel further comprises a monitoring module, wherein the monitoring module is used for monitoring the state parameter of the currently played video, and if the state parameter is abnormal, the monitoring module generates an alarm signal according to the abnormal state parameter, and/or automatically completes the emergency signal switching of the currently played video.

The utility model has the advantages that: the utility model provides a pair of a controlling means for emergent switching of video includes: the control panel, the input end of the control panel is connected with broadcasting equipment, the said broadcasting equipment provides the corresponding state parameter according to the channel that the control panel chooses at present, the control panel responds to the unusual state parameter, send out the control command; and the control panel server is in communication connection with the control panel and is used for acquiring the state parameters of the broadcasting equipment, providing the state parameters to the control panel, setting the on-off of the main video server signal lines according to the control instruction, and switching the current video playing channel line to one of the alternative channel lines or switching the current broadcasting equipment to the alternative broadcasting equipment. Therefore, under the integrated broadcasting framework, when one or more conditions of video server broadcasting signal abnormity, server hardware (broadcasting equipment) fault and subtitle emergency processing occur, the switching of a plurality of channels can be supported, and the maximum number of image-text paths supported by each channel and the external input signal switching can be set, so that the reliability of video emergency switching is ensured, and the working efficiency is improved.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings.

Fig. 1 shows a schematic structural diagram of a control device for video emergency switching according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a front layout of a control panel in the control device of FIG. 1;

fig. 3 is a schematic layout view of the back side of the control panel in the control device shown in fig. 1.

Detailed Description

In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. The preferred embodiments of the present invention are shown in the drawings. The invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

In the technical field of television broadcasting, broadcasting safety is a factor which is primarily considered when a television station designs and constructs a broadcasting control system. Safe broadcasting is the ultimate goal of each television station broadcasting system. However, before being actually played out, the video signal is converted and distributed by many devices, which often have an adverse effect on the video picture quality and content of the video signal. Meanwhile, manual misoperation inevitably exists in the television broadcasting process, and the problems of poor broadcasting such as black fields, color strips, mosaics, silent frames, popping and the like are often caused. Therefore, it is important to improve the broadcast control system to improve the broadcast security. One way to improve the broadcasting safety is to accurately and timely monitor the final signal and switch the normal video signal to be output as the broadcasting signal. Specifically, in the system construction, an emergency system needs to be arranged for ensuring safe broadcasting, and a technical supervision system needs to be added for monitoring and monitoring the broadcasting of programs; in order to perform the active/standby switching at any time, signal synchronization needs to be performed, and a synchronization system needs to be added. In addition, system backup, line backup, port backup and the like are determined according to the properties and disadvantages of the respective subsystems.

The emergency system is the basic guarantee for the safe broadcasting of programs. The video signal backup is mainly divided into two parts: the vast majority of all-day program materials are stored in a video server, and the video server is a main video source for broadcasting programs; the other part of the live broadcast signal comes from an external field signal, such as a studio signal, a live broadcast car signal and the like. The video server basically adopts a mirror image structure of the main video server and the standby video server and broadcasts the video simultaneously. The main broadcasting control program controls the decoding channel of the main video server to broadcast main broadcasting signals, and the standby broadcasting control program controls the decoding channel of the standby video server to broadcast standby broadcasting signals. The main broadcast and the standby broadcast signals are simultaneously input into the signal switching equipment, the standby server is respectively connected with the main VLAN switch and the main optical fiber switch by monitoring pictures on the signal monitor, and is connected with the file exchanger, the service manager and the file controller by the VLAN switch to realize the storage and the calling of program materials, and is connected with the disk controller and the disk array cabinet by the optical fiber switch to realize the access of files. Due to the structure of mutual backup, when any switch goes wrong, the link communication cannot be influenced, and the broadcasting safety is ensured. The live broadcast signal generally has two or more channels of signals connected to the broadcasting system, and the main channel is immediately switched to the standby channel signal when a problem occurs.

When the main video server and the standby video server simultaneously have faults, manual broadcasting can be carried out through the matrix, and an operator on duty selects one path of signal as final output through a program or directly manually controlling the switching equipment. However, the method has the disadvantage that whether the broadcast station breaks down or not is judged subjectively by the broadcast operator and the emergency operation is carried out in time, so that the high safety of the broadcast of the television station cannot be ensured. When the video server has broadcast signal abnormity, server hardware fault, or one or more conditions of emergency signal switching and caption emergency treatment are required, the conventional equipment cannot realize rapid, efficient and convenient emergency switching.

Based on the problem, the utility model provides a controlling means for emergent switching of video broadcasts the video server of framework to ALL-IN-ONE, can appear broadcasting signal unusual, server hardware trouble IN this video server, or when will carrying out emergent switching, the emergent processing of caption of picture and text layer or built-IN matrix ONE kind or the multiple condition IN, quick, high-efficient, convenient completion is emergent to be switched, guarantees the reliability when the emergent switching of video, has improved work efficiency simultaneously.

The present invention will be described in detail below with reference to the accompanying drawings.

Fig. 1 shows a schematic structural diagram of a control device for video emergency switching according to an embodiment of the present invention.

Referring to fig. 1, an embodiment of the present invention provides a control device 10 for video emergency switching, including: a control panel 200 and a control panel server 100 communicatively connected to the control panel 200, wherein an input end of the control panel 200 is connected to a broadcasting device 30, the broadcasting device 30 provides corresponding status parameters according to a currently selected channel of the control panel 200, and the control panel 200 issues a control command in response to an abnormal status parameter; the control panel server 100 is configured to obtain the status parameters of the playing device 30 and provide the status parameters to the control panel 200, and set the on/off of the signal lines of the main and standby video servers 20 (such as the video server 1 and the video server 2 … …) according to the aforementioned control instruction, switch the channel line of the currently playing video to one of the alternative channel lines, or switch the current playing device (such as the playing device 1) to the alternative playing device (such as the playing device 2).

Further, the aforementioned status parameters include, but are not limited to: the signal connection state of the current broadcasting equipment (such as broadcasting equipment 1), the current channel information, the broadcast video information, and the signal state and the display state of the caption layer corresponding to the current channel, and the abnormal state parameters are: at least one of the signal connection state, the current channel information, the playing video information, and the signal state and the display state of the caption layer corresponding to the current channel of the current playing device (such as the playing device 1) is abnormal.

Further, the aforementioned control instructions include: specifically, the channel lamp instruction is used for indicating a currently selected channel line, the external input signal instruction is used for selecting a signal source for externally playing a video signal, the external input signal may be, but is not limited to, a video signal for synchronizing live broadcast or a video signal for calling a playing material, and the heartbeat connection instruction is used for indicating a synchronous operation between the main and standby video servers 20. For example, in a play system, the control of all devices is realized by using two synchronous inverters (such as RS-232/422 inverters) in a manner of master/slave control workstations. The main path broadcasting control workstation controls the main controlled equipment, the standby path control workstation controls the main controlled equipment, and the standby path control workstation controls the main controlled equipment and the standby path equipment to broadcast respectively by utilizing heartbeat monitoring of the two workstations to carry out synchronous operation. When the main broadcasting control workstation has a fault, the standby broadcasting control workstation automatically uses the GPI to trigger a synchronous inverter connected with the main control equipment, so that the standby broadcasting control workstation transfers the control right to the standby broadcasting control workstation, and the standby broadcasting control workstation realizes the control of all the equipment. When the standby broadcasting control workstation has a fault, the control right of the synchronous switcher needs to be manually switched to the main broadcasting control workstation, and the main broadcasting control workstation is used for controlling all the equipment to broadcast, so that the stability of video signal switching is improved, and the effect of uninterrupted broadcasting during switching is ensured.

Fig. 2 is a schematic layout diagram illustrating a front side of a control panel in the control device shown in fig. 1, and fig. 3 is a schematic layout diagram illustrating a rear side of the control panel in the control device shown in fig. 1.

Further, the control panel 200 includes a switching module (not shown), referring to fig. 2, which includes:

a plurality of channel selection switches 210 arranged in an array;

a plurality of input selection switches 220 arranged in an array, wherein the plurality of input selection switches 220 correspond to any channel selected by the channel selection switch 210 and can correspondingly select one of a plurality of external input signals for inputting, and the plurality of external input signals are synchronous live video signals (such as studio signals, live car signals and the like) or video signals of called playing materials, and synchronous live video signals or backup signals of the called video signals of the playing materials;

a plurality of image-text selection switches 230 arranged in an array, wherein the image-text selection switches 230 are corresponding to any channel selected by the channel selection switch 210, and can correspondingly select at least one image-text path number, specifically, for example, for displaying station captions (including corner captions, sub-captions and floating) and caption layers;

a locking switch 240, wherein the locking switch 240 is used for providing locking or unlocking of a selection switch on the control panel 200, so as to prevent lines or signals from being disturbed due to malfunction and influence on broadcasting safety.

Further, the control panel 200 further includes: a power module having at least two power interfaces 261 and a communication interface module (not shown), which is illustrated in fig. 3 by having two power interfaces 261 in this embodiment. The independent Power supplies correspondingly connected to the at least two Power interfaces 261 are mutually Redundant, and it is known that a Redundant Power System (RPS) is generally a Power supply used in a server, and is composed of two identical Power supplies, and a chip control Power supply is used for load balancing, and when one Power supply fails, the other Power supply can take over the work of the other Power supply, so that the high availability of the server System is realized. In this embodiment, the power module is configured to select one of the at least two power sources to be powered on, so as to ensure that playing is not interrupted due to a power failure problem during playing.

In this embodiment, the communication interface module has at least two serial communication interfaces 271 (such as RS422 interfaces), and in this embodiment, the communication interface module takes two serial communication interfaces 271 as an example, as shown in fig. 3. One part of the at least two serial communication interfaces 271 is connected to the broadcast device 30 and the control panel server 200, and is configured to receive the status parameters and send the control command, and further, for example, at least two of the other parts of the serial communication interfaces 271 are connected to the active/standby server 20, so as to support the operation of dual power supplies.

Further, the control panel 200 further includes a switching display module connected to the switching module, and the switching display module includes: a power indicator lamp 250 and a switch status lamp (not shown), wherein the power indicator lamp 250 is used to indicate a selected operating power; the on-off status lights are controlled by the aforementioned switching module, in one-to-one correspondence with the respective selection switches (the channel selection switch 210 and the input selection switch 220) and the lock switch 240, for indicating the operation status of the switches (the channel selection switch 210 and the input selection switch 220) corresponding thereto.

In a preferred embodiment, any one of the aforementioned selection switches (the channel selection switch 210 and the input selection switch 220) and the locking switch 240 is a key switch, and the aforementioned switch status light is embedded in the corresponding key switch, as shown in fig. 2, wherein the first row of keys are the channel selection switches 210 that can be selectively controlled, and at most 16 keys can be set; the lower row of left keys are selection switches 220 which can support external input signals per channel and can be set to be 11 at most; the lower row of right keys is a graphic selection switch 230 which can support the number of graphic paths of each channel, the maximum number of digits can be 5, the key switches are all 17 × 17mm luminous self-recovery keys, and the keys support embedded film characters, so that the red, green, orange and off states can be indicated. The left LED indicator 250 of the control panel 200, the first two are power indicators, and the third is an LED indicator for controlling the status of the connection; the control panel 200 has a lock switch 240 at a lower left side thereof for preventing a mis-touch operation. The lamp is on after the switch is pressed, the locking state is at the moment, and the key switch of the operation function is invalid; after the switch is bounced, the switch is in a non-locking state, and the key switch can be normally operated.

In this embodiment, the control panel server 100 sends the channel layer display state to the control panel 200 according to the currently selected channel (for example, channel 1) of the control panel 200, the control panel 200 sets the layer signal lamp on and off states according to the state parameters including the channel layer display state, and sends a layer down instruction (designated channel and layer) to the control panel server 100 through the serial port, and the control panel server 100 sends the layer down instruction to the broadcast device 30 through the network, thereby achieving the broadcast control purpose.

When the control panel 200 is switched by the channel selection switch 210, the playing system may obtain the aforementioned state parameters (such as the layer display information corresponding to the current channel, the signal connection state of the current playing device, the current channel information, the playing video information, and the like) from the control panel server 100, and set the state of the layer lamp (on-off state lamp).

The keys of the lock switch 240 provide the lock function of the control panel 200, and when pressed, the panel is in a lock state except for the keys of the lock switch 240, and the trigger is disabled. When the key of the lock switch 240 is popped up, the key switch function is activated.

In another preferred embodiment, any one of the aforementioned selection switches (the channel selection switch 210 and the input selection switch 220) and the lock switch 240 is a toggle switch, and the aforementioned on-off status light is located in the vicinity of the corresponding toggle switch.

In another preferred embodiment, the control panel 200 includes, for example, a touch display screen for displaying the aforementioned status parameters, and the touch operations of the aforementioned selection switches (the channel selection switch 210 and the input selection switch 220) and/or the aforementioned lock switch 240.

Further, the control panel 200 further includes a monitoring module, which is configured to monitor a status parameter of the currently played video, and if the status parameter is abnormal, the monitoring module generates an alarm signal according to the abnormal status parameter, and/or automatically completes switching of an emergency signal of the currently played video.

To sum up, the embodiment of the present invention provides a control device 10 for video emergency switching, which utilizes a control panel 200 to connect with a broadcasting device 30, obtains the state parameters correspondingly provided by the broadcasting device 30 according to the currently selected channel of the control panel 200, and sends a control instruction in response to the abnormal state parameters; then, the control panel server 100 in communication connection with the control panel 200 sets the on/off of the signal lines of the main and standby video servers 20 according to the control instruction, and switches the channel line of the currently playing video to one of the alternative channel lines, or switches the currently playing device (e.g., the playing device 1) to an alternative playing device (e.g., the playing device 2). Therefore, under an integrated broadcasting framework, when one or more conditions of video server broadcasting signal abnormity, server hardware (broadcasting equipment) failure and caption emergency treatment occur, the control device 10 can support the switching of a plurality of channels, and the maximum number of image-text channels supported by each channel and the switching of external input signals, thereby ensuring the reliability of video emergency switching and improving the working efficiency.

It should be noted that in the description of the present invention, it is to be understood that the terms "upper", "lower", "inner", and the like, indicate positional or positional relationships for convenience of description of the present invention and to simplify the description, but do not indicate or imply that the components or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

Further, in this document, the contained terms "include", "contain" or any other variation thereof are intended to cover a non-exclusive inclusion, so that a process, a method, an article or an apparatus including a series of elements includes not only those elements but also other elements not explicitly listed or inherent to such process, method, article or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

Finally, it should be noted that: it should be understood that the above examples are only for clearly illustrating the present invention and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious changes and modifications may be made without departing from the scope of the present invention.

Claims (10)

1. A control device for video emergency switching, comprising:

the control panel, the input end of the control panel is connected with broadcasting equipment, the said broadcasting equipment provides the corresponding state parameter according to the channel that the control panel chooses at present, the said control panel responds to the said state parameter of the anomaly, send out the control command;

and the control panel server is in communication connection with the control panel and is used for acquiring the state parameters of the broadcasting equipment, providing the state parameters to the control panel, setting the on-off of the signal lines of the main video server and the standby video server according to the control instruction, and switching the channel line of the currently played video to one of the alternative channel lines or switching the currently played equipment to the alternative broadcasting equipment.

2. The control device according to claim 1, wherein the state parameters include: the signal connection state of the current broadcasting equipment, the current channel information, the broadcasting video information, the signal state and the display state of the caption layer corresponding to the current channel,

and the abnormal state parameters are: and at least one of the signal connection state of the current broadcasting equipment, the current channel information, the broadcasting video information, and the signal state and the display state of the caption layer corresponding to the current channel is abnormal.

3. The control device according to claim 2, wherein the control instruction includes: a channel lamp instruction, an external input signal instruction, a graphic and text path number instruction and a heartbeat connection instruction.

4. The control device of claim 3, wherein the control panel comprises a switching module comprising:

a plurality of channel selection switches arranged in an array;

the system comprises a plurality of input selection switches arranged in an array, a plurality of video signal processing units and a plurality of video signal processing units, wherein any channel selected by the corresponding switch can be correspondingly selected to input one of a plurality of external input signals, and the plurality of external input signals are synchronous live video signals or called video signals of playing materials;

the image-text selection switches are arranged in an array, and at least one image-text path number can be correspondingly selected corresponding to any channel selected by the switches;

and the locking switch is used for providing locking or unlocking of the selection switch on the control panel.

5. The control device of claim 4, wherein the control panel further comprises:

the power supply module is provided with at least two power supply interfaces, the at least two power supply interfaces are respectively and correspondingly connected with independent power supplies, and the power supply module is used for selecting one of the at least two power supplies to be conducted for power supply;

and the communication interface module is provided with at least two serial communication interfaces, and the at least two serial communication interfaces are respectively connected with the broadcasting equipment and the control panel server and are used for receiving the state parameters and sending the control instruction.

6. The control device of claim 5, wherein the control panel further comprises a switching display module connected to the switching module, the switching display module comprising:

a power indicator for indicating a selected power source;

and the switch state lamps are controlled by the switching module, correspond to the selection switches and the locking switches one by one and are used for indicating the operation states of the corresponding switches.

7. The control device of claim 6, wherein any one of the selection switch and the locking switch is a key switch, and the switch status light is internally arranged in the corresponding key switch.

8. The control device of claim 6, wherein either one of the selector switch and the lock switch is a toggle switch, and the switch status light is located in proximity to the corresponding toggle switch.

9. The control device according to claim 5, wherein the control panel comprises a touch display screen for displaying the status parameters and touch operations of the selection switch and/or the lock switch.

10. The control device according to claim 1, wherein the control panel further comprises a monitoring module, the monitoring module is configured to monitor a status parameter of the currently playing video, and if the status parameter is abnormal, the monitoring module generates an alarm signal according to the abnormal status parameter, and/or automatically completes emergency signal switching of the currently playing video.

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