JP6979641B2 - Video switcher and video switch method - Google Patents

Description

The present invention relates to a video switcher and a video switch method.

In recent years, the number of video transmission devices that employ a method that uses multiple optical links for optical data transmission has increased as broadcasting equipment, and devices that have the function of switching video data transfer paths in these devices are called video switchers. ing.

In the ultra-high-definition television signal studio device-to-device interface standard (ARIB-STD-B58) revised by the Association of Radio Industries and Businesses in 2015, the next-generation 8K television from the conventional 2K and 4K television Definitions of the physical layer used for the signal format and transmission of.

In 8K television, frame data composed of a minimum color signal component of 7680 × 4320 × 3 per screen is transmitted 60 or 120 times per second. For example, if the color signal component (G: B: R) has a ratio of 4: 4: 4 and 120 frames are transmitted per second, the physical interface defined as a 10G link signal has 24 links. used. The physical interface is a single mode using a method in which a 10G link signal is transmitted using a plurality of multimode fibers and a DWDM wavelength division multiplexing technology in which a different wavelength band is assigned to each 10G link signal and multiplexed. The method of transmission by fiber is defined.

As for the auxiliary data, the provisions in the common standard for auxiliary data (BTA S-005) for the 1125/60 system HDTV bit series interface revised in 2012 by the association are followed as they are.

FIG. 1 is a diagram showing a configuration example of a video switcher using a conventional electric switch architecture, and is an optical link # 1 to # n for transmitting A-system video content and an optical link # 1 to for transmitting B-system video content. # N and can be switched to two routes. Each optical link is a 10G link.

In FIG. 1, the optical links # 1 to # n of the video content of the A system and the optical links # 1 to # n of the video content of the B system are connected to the optical / electrical conversion unit (Optical / Electronic) OE, respectively, and are optical signals. Is converted into an electric signal and input to the electric switch unit SW. The electric switch unit SW is a device such as a crossbar switch, an analog switch, or an FPGA (Field Programmable Gate Array). Then, the signal output after the route is switched inside the electric switch unit SW is converted from the electric signal to the optical signal by the electric / optical conversion unit (Electronic / Optical) EO, respectively, and the optical link # of the two video contents. It is connected to 1 to # n respectively.

As shown in FIG. 2, the switching timing in the electric switch unit SW is defined as a switching point (switching allowable period) in the auxiliary data line “7” in the frame, and switching is performed within that period. The switching point period is about 6.46 μsec.

Japanese Unexamined Patent Publication No. 2006-310946

In the video switcher with the above-mentioned electric switch architecture, the optical signal is converted into an electric signal, and after switching the route, the optical signal is converted again. Therefore, many devices are required, and the increase in power consumption and cost becomes a problem. Was there.

On the other hand, there is a MEMS (Micro Electro Mechanical Systems) switch represented by, for example, a large-scale optical switch as a method of switching a path directly in the state of an optical signal. However, since the MEMS switch has a low switching time of several msec order, it is mainly limited to static data switching applications such as line redundancy switching, maintenance, inspection, and patch applications (for example, Patent Document 1). See).

In addition, a high-speed PLZT ((Pb, La) (Zr, Tr) O ₃ : lead zirconate titanate lanthanum lead) optical switch with a switching time of nsec order is promising from the viewpoint of switching time. However, the PLZT optical switch or the like has a small number of ports, and it is difficult to collect a plurality of optical links.

These problems are factors that hinder the dynamic switching of video content routes to a system that transmits data using a plurality of 10G links defined by the above-mentioned ARIB-STD-B58.

The present invention has been proposed in view of the above-mentioned conventional problems, and an object of the present invention is to provide a video switcher capable of efficiently and dynamically switching routes of video content input by a plurality of optical links. There is something in it.

In order to solve the above problems, in the present invention, a plurality of optical links are accommodated for each video content, and the signals of the plurality of optical links are wavelength-multiplexed on one fiber for each video content. A wave filter unit, a monitoring unit that monitors the timing of the switching point of the optical link, a control unit that controls optical path switching based on the timing of the switching point notified from the monitoring unit, and light from the control unit. It has an optical switch unit that switches and outputs the path of the optical signal whose wavelengths are multiplexed by the plurality of combined wave filter units according to the path switching control signal.

In the present invention, it is possible to dynamically switch the route of video content input by a plurality of optical links with high efficiency.

It is a figure which shows the configuration example of the video switcher by the conventional electric switch architecture. It is a schematic diagram of the switching point defined in the ARIB standard. It is a figure which shows the structural example of the video switcher which concerns on 1st Embodiment of this invention. It is a figure (the 1) which shows the example of the connection between an optical link and a monitoring unit. It is a figure (the 2) which shows the example of the connection between an optical link and a monitoring unit. It is a figure which shows the timing example of the signal change in 1st Embodiment. It is a figure which shows the structural example of the video switcher which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structural example of the video switcher which concerns on 3rd Embodiment of this invention. It is a figure which shows the timing example of the signal change in 3rd Embodiment. It is a figure which shows the structural example of the video switcher which concerns on 4th Embodiment of this invention. It is a figure which shows the structural example of the video switcher which concerns on 5th Embodiment of this invention. It is a figure which shows the example of determination of the delay amount, the presence / absence of an error, and the switching timing in 5th Embodiment. It is a figure which shows the structural example of the video switcher which concerns on 6th Embodiment of this invention. It is a figure which shows the example which the phase is adjusted in 6th Embodiment. It is a figure which shows the structural example of the video switcher which concerns on 7th Embodiment of this invention. It is a figure which shows the structural example of the video switcher which concerns on 8th Embodiment of this invention. It is a figure which shows the example which the phase is adjusted in 8th Embodiment.

Hereinafter, preferred embodiments of the present invention will be described.

<First Embodiment>
FIG. 3 is a diagram showing a configuration example of the video switcher 1 according to the first embodiment of the present invention. In FIG. 3, two or more types of video contents to be switched are shown as A system and B system, but of course, more than that may be used. The optical links # 1 to # n that transmit the video content of each system are assumed to be 10G links, and the number of links (number of signals) varies depending on the type of color signal component of the video content, but at least 24 links. Up to 6 links are used. Further, the optical links # 1 to #n of each system are assigned wavelengths λ1 to λn according to ITU-T G.694.1 for DWDM (Dense Wavelength Division Multiplexing). Further, the optical links # 1 to #n of each system are frame-synchronized by a device called a frame synchronizer. This is because, for example, if the various infrastructures used for broadcasting video such as cameras, editing machines, and recorders are asynchronous, the frame timing will shift and the images will be distorted, so it is necessary to synchronize them in advance. ..

The optical links # 1 to # n for transmitting the video content of the A system are input (accommodated) to the combined wave filter unit 101A, and the optical links # 1 to # n for transmitting the video content of the B system are input (accommodated) to the combined wave filter unit 101B. Entered (accommodated). Then, they are output to one fiber as optical signals that are combined and wavelength-multiplexed. The outputs of the combined wave filter units 101A and 101B are input to an optical switch unit 102 such as a PLZT optical switch, and an optical signal selected for each combined video content is output. Not only when one of the optical signals of the video content of the two systems (multi-system is also possible) is selected and output, but each of the two systems (multi-system is also possible) is output to a different route. It may be a thing. When one of the two systems is output, the 2 × 1 port optical switch unit 102 is used, and when each of the two systems is output to a different route, the 2 × 2 port optical switch unit 102 is used.

On the other hand, the monitoring unit 103 that monitors the timing of the switching point from the signal of one of the optical links (optical link # 2 of system B in the illustrated example), the operation unit 104 that accepts the switching operation from the operator, and the monitoring unit 103. A switching point to be monitored and a control unit 105 for performing switching control of the optical switch unit 102 according to a switching operation from the user are provided. The operation unit 104 only needs to be able to notify the control unit 105 of the video content that the operator wants to select. For example, a CLI (Command Line Interface) using a PC (Personal Computer), a GUI (Graphical User Interface), and a mechanical push button switch. It may be composed of. The control unit 105 adjusts the switching timing of the optical switch unit 102 based on the switching point information notified from the monitoring unit 103, and switches the optical switch unit 102 according to the video content selection information from the operation unit 104. Take control.

FIG. 4 is a diagram showing an example of connection between the optical link and the monitoring unit 103. In FIG. 4, for example, an optical / electrical conversion unit 106 and an electric / optical conversion unit 107 are inserted in series in the connection path between the optical link # 2 of the B-system video content and the combined wave filter unit 101B, and the light / electricity is optical / electric. The output of the conversion unit 106 is input to the monitoring unit 103. According to this configuration, the optical / electrical conversion unit 106 and the electric / optical conversion unit 107 are required, but since only one 10G link is required, it is compared with the video switcher (FIG. 1) of the conventional electric switch architecture. , Increased power consumption and cost are not a problem.

FIG. 5 is a diagram showing another example of the connection between the optical link and the monitoring unit 103. In FIG. 5, for example, the main path of the light demultiplexing section 108 is inserted into the connection path between the optical link # 2 of the video content of the B system and the combined wave filter section 101B, and the optical / electrical conversion section 109 is inserted into the branch path. Is connected, and the output of the optical / electrical conversion unit 109 is input to the monitoring unit 103. According to this configuration, since it is only necessary to provide the light demultiplexing unit 108 and the optical / electric conversion unit 109, it is possible to reduce power consumption and cost as compared with the configuration of FIG.

The method of connecting the optical link and the monitoring unit 103 shown in FIGS. 4 and 5 can also be applied to the embodiment described later using the monitoring unit 103.

FIG. 6 is a diagram showing an example of timing of signal change in the first embodiment. In FIG. 6, the stream of each video content is frame-synchronized in advance by the frame synchronizer as described above. Then, the monitoring unit 103 notifies the control unit 105 of the detection pulse at the head portion of the switching point, and the control unit 105 has a video stream currently selected by the optical switch unit 102 and a video stream requested by the operation unit 104. If is different from the above, the optical switch unit 102 is switched at the timing of the subsequent detection pulse (the timing of the falling edge in the illustrated example).

<Second embodiment>
FIG. 7 is a diagram showing a configuration example of the video switcher 1 according to the second embodiment of the present invention, in which the timing of the switching point detected by the monitoring unit 103 and the switching of the video frame input to the optical switch unit 102. This is to deal with the case where a large delay time occurs between the timing of the point or the timing when the switching is actually performed. Causes of the delay time include the optical fiber delay time, the delay time of the logic and the like constituting the monitoring unit 103, and the switching time of the optical switch unit 102 itself, and the switching in the optical switch unit 102 is the switching point period as it is. It is assumed that it does not fit within.

In FIG. 7, delay lines 110A and 110B for adjusting the optical fiber length are provided in the connection path between the combined wave filter units 101A and 101B and the optical switch unit 102, respectively, and are next to the frame of the switching point detected by the monitoring unit 103. It is designed to delay to the switching point of the frame. Since it is premised that the A-system and B-system video contents are frame-synchronized by the frame synchronizer, the delays added by the delay lines 110A and 110B are the same amount.

As a result, switching in the optical switch unit 102 is completed within the switching point period.

<Third embodiment>
FIG. 8 is a diagram showing a configuration example of the video switcher 1 according to the third embodiment of the present invention, in which the delay time is dealt with by the function of the control unit 105 without using the delay line. ..

In FIG. 8, a delay counter 111 is provided in the control unit 105, starts counting a predetermined clock from the arrival of a detection pulse of a switching point notified from the monitoring unit 103, and when the control unit 105 reaches a predetermined count value. The optical switch unit 102 is switched. Other configurations are similar to those shown in FIG.

FIG. 9 is a diagram showing an example of timing of signal change in the third embodiment. In FIG. 9, when the monitoring unit 103 notifies the control unit 105 of the detection pulse from the head portion of the switching point at the timing of the delay α, the delay counter 111 of the control unit 105 starts counting based on a predetermined internal clock. .. Then, when the count value becomes a predetermined value (“6” in the illustrated example) corresponding to an appropriate timing of the switching point period of the next frame, the video stream currently selected by the optical switch unit 102 is used. The optical switch unit 102 is switched on condition that the video stream requested by the operation unit 104 is different.

<Fourth Embodiment>
FIG. 10 is a diagram showing a configuration example of the video switcher 1 according to the fourth embodiment of the present invention, in which adjustment for the delay time is automatically performed.

In FIG. 10, a line error check unit 112 is connected to the output of the optical switch unit 102, and a check code provided for each line in the frame is checked from an arbitrary optical link frame of the output video content. , The result is notified to the control unit 105. As the check code, in addition to CRCC (Cyclic Redundancy Check Code), parity of 10B code of data or the like can be used. As for the implementation of the connection on the input side of the line error check unit 112, the output path of the optical switch unit 102 in FIG. 10 is similar to the light demultiplexing unit 108 and the optical / electrical conversion unit 109 shown in FIG. An optical demultiplexing unit is provided, and the output of the optical / electrical conversion unit connected to the branch path is input to the line error check unit 112. The same applies to the line error check unit 112 in the subsequent embodiments. Other configurations are similar to those shown in FIG.

The control unit 105 switches the optical switch unit 102 based on the delay count value every time the predetermined count value (delay count value) for switching control is incremented or decremented at the time of automatic adjustment, and the line error check unit 112. Monitor the CRCC error information sent from. Then, the control unit 105 adjusts the delay count value until the time when the CRCC error does not occur, and determines the optimum value of the delay count value.

<Fifth Embodiment>
FIG. 11 is a diagram showing a configuration example of the video switcher 1 according to the fifth embodiment of the present invention, in which adjustment for the delay time is automatically performed and adjustment is performed at a more appropriate timing. Is.

In FIG. 11, the control unit 105 is provided with a delay insertion unit 113 capable of increasing or decreasing the delay time in units of minute Δt with respect to the detection pulse notified from the monitoring unit 103. Further, a line error check unit 112 is connected to the output of the optical switch unit 102, and a check code (CRCC) provided for each line in the frame is checked from an arbitrary optical link frame of the output video content. The result is notified to the control unit 105. Other configurations are similar to those shown in FIG.

FIG. 12 is a diagram showing an example of determining the delay amount, the presence / absence of an error, and the switching timing in the fifth embodiment. In FIG. 12A, the presence / absence of an error by the line error check unit 112 when the delay time by the delay insertion unit 113 is increased by Δt from 0 is indicated by “◯” (no error) and “×” (with error). ) Is an example shown. In this case, the control unit 105 does not simply set the timing when the timing without error is reached as the timing of switching control, but as shown in FIG. 12B, for example, after "x" follows, "○". The timing at which two "○" are continued after changing to "" is regarded as the timing of switching control. This is to avoid an error during long-term use when the optical signal has jitter and immediately changes from "x" to "○". In addition, in the latter part of the section of "○", that is, in the latter half of the switching point period, word synchronization is performed by the high-speed serial transfer method "8B10B" in the subsequent circuit, and there is a possibility that an error of 2 words may occur in the worst case. Therefore, it is for avoiding that the word in which the error occurs is valid data such as an image signal. Therefore, the switching timing is set in the first half of the period of "○".

This enables switching control of the optical switch unit 102 at the optimum timing even during the switching point period.

<Sixth Embodiment>
FIG. 13 is a diagram showing a configuration example of the video switcher 1 according to the sixth embodiment of the present invention, in the case where the combine wave filter unit for combining the video contents of each system exists at a place away from the optical switch unit. Is an example of. Generally, video content is generated in a studio or the like, and it may be advantageous to provide a combined wave filter unit on the studio side for efficient use of optical fibers.

In FIG. 13, the combined wave filter unit 101A that combines the optical links # 1 to # n for transmitting the video content of the A system is provided in the transmission unit 11A, and the optical links # 1 to # for transmitting the video content of the B system. The combiner filter unit 101B for combining n is provided in the transmission unit 11B, and the optical signal combined with each of them is focused on the switch unit 12 via a fiber having an indefinite length. In the switch unit 12, the combined wave signal of the A system is input to the optical switch unit 102 via the wavelength drop unit 114A and the delay line 110A, and the combined wave signal of the B system is optical via the wavelength drop unit 114B and the delay line 110B. It is input to the switch unit 102. Further, monitoring units 103A and 103B for monitoring the timing of the switching point from the signals dropped from the wavelength drop units 114A and 114B (for example, the signal having the wavelength λ2) are provided, and the switching point detection pulse is transmitted from the monitoring units 103A and 103B. The control unit 105 is notified. Further, the control unit 105 controls the delay of the delay lines 110A and 110B according to the timing shift of the detection pulse notified from the monitoring units 103A and 103B, in addition to controlling the switching of the optical switch unit 102. It has become. The operation unit 104 is the same as that described in the previous embodiments. The line error check unit 112 is provided when the delay time caused by the monitoring units 103A, 103B, etc. is automatically adjusted.

When the transmission unit 11A of the video content of the A system and the transmission unit 11B of the video content of the B system exist at a location away from the switch unit 12, the video content of the A system and the B system are synchronized at the frame level by the frame synchronizer. However, depending on the length of the optical fiber and the location of the studio, the phase may be out of phase when the switch unit 12 is reached. Therefore, it is necessary to match the phases of each of them before the input to the optical switch unit 102.

In the present embodiment, the control unit 105 controls the delay of the delay lines 110A and 110B according to the timing shift of the detection pulse notified from the monitoring units 103A and 103B, so that the A is input to the optical switch unit 102. Phase matching of the system and B system video contents is performed.

FIG. 14 is a diagram showing an example in which the phase is adjusted in the sixth embodiment. FIG. 14 (a) shows an initial state in which a delay occurs between the video contents of the A system and the B system, and FIG. 14 (b) shows the video content of the A system with an advanced phase delayed. This indicates that the phases of both systems are in agreement.

Subsequent measures for switching control of the optical switch unit 102 and the delay time caused by the monitoring units 103A, 103B, etc. are performed in the same manner as in the above-described embodiment.

<7th Embodiment>
FIG. 15 is a diagram showing a configuration example of the video switcher 1 according to the seventh embodiment of the present invention, in which the switch unit 12 performs phase matching of the video content arriving at the switch unit 12 from the transmission units 11A and 11B. Instead, the frame synchronizers 2A and 2B provided on the transmission units 11A and 11B are used.

FIG. 15 shows FIG. 13 except that the switch unit 12 does not have the delay lines 110A and 110B and the delay control signal is transmitted from the control unit 105 to the frame synchronizers 2A and 2B provided on the transmission units 11A and 11B. Is similar to.

In the present embodiment, the control unit 105 detects the phase shift of both systems according to the timing shift of the detection pulse notified from the monitoring units 103A and 103B, and causes the frame synchronizer (2Aor2B) of the advanced phase system. Send a delay control signal. After receiving the delay control signal, the frame synchronizer (2Aor2B) delays the transmission of the signal, and as a result, the phases of the video contents of both systems reaching the switch unit 12 are matched.

Subsequent measures for switching control of the optical switch unit 102 and the delay time caused by the monitoring units 103A, 103B, etc. are performed in the same manner as in the above-described embodiment.

<Eighth Embodiment>
FIG. 16 is a diagram showing a configuration example of the video switcher 1 according to the eighth embodiment of the present invention, in which the monitoring unit is omitted. FIG. 16 shows a case where the wavelength drop units 114A and 114B and the monitoring units 103A and 103B are removed from the configuration shown in FIG. 13 and the line error check unit 112 is made essential. It can also be applied to the above-described embodiment. That is, not only the phase matching of the video content reaching the switch unit 12 from the transmission units 11A and 11B, but also the timing adjustment of the original switching control of the optical switch unit 102 is performed.

In the present embodiment, at the time of automatic adjustment, adjustment is performed for each of the A system and the B system in a state where the other signal does not flow. If the switching of the optical switch unit 102 is turned ON / OFF / ON in a short time (for example, 10 ns) and a bit error is intentionally caused at the timing of switching, the other signal may be passed.

The control unit 105 adjusts the delay times of the delay lines 110A and 110B at a timing at which an error is not detected in the line error check unit 112 with respect to the original switching timing (preferably the first half of the switching point period as described above). Therefore, the phases of both systems are matched, and the switching timing of the optical switch unit 102 is also appropriate for the switching point.

FIG. 17 is a diagram showing an example in which the phase is adjusted in the eighth embodiment. As shown in FIG. 17 (a), the video content of the A system is delayed until the timing at which an error does not occur in the unique switching timing of the control unit 105, and the video content of the B system is also shown in FIG. 17 (b). Since the delays are made to the same timing as described above, the phases of both systems are matched, and the timing of the switching control of the optical switch unit 102 is also adjusted. As a result, the monitoring unit becomes unnecessary.

<Summary>
As described above, according to the present embodiment, it is possible to dynamically switch the route of the video content input by the plurality of optical links with high efficiency.

The present invention has been described above according to a preferred embodiment of the present invention. Although the present invention has been described herein with reference to specific examples, various modifications and modifications may be made to these specific examples without departing from the broad intent and scope of the invention as defined in the claims. It is clear that you can. That is, it should not be construed that the present invention is limited by the details of the specific examples and the accompanying drawings.

1 Video switcher 101, 101A, 101B Combined wave filter unit 102 Optical switch unit 103, 103A, 103B Monitoring unit 104 Operation unit 105 Control unit 106 Optical / electrical conversion unit 107 Electric / optical conversion unit 108 Light demultiplexing unit 109 Optical / electric Conversion unit 110, 110A, 110B Delay line 111 Delay counter 112 Line error check unit 113 Delay insertion unit 114, 114A, 114B Wavelength drop unit 11, 11A, 11B Transmission unit 12 Switch unit 2, 2A, 2B Frame synchronizer

Claims (12)

A plurality of combined wave filter units that accommodate a plurality of optical links for each video content and wavelength-multiplex the signals of the plurality of optical links into one fiber for each video content.
A monitoring unit that monitors the timing of the switching point of the optical link,
A control unit that controls optical path switching based on the timing of the switching point notified from the monitoring unit, and a control unit.
A video switcher including an optical switch unit that switches and outputs an optical signal path whose wavelength is multiplexed by the plurality of combined wave filter units in response to an optical path switching control signal from the control unit. The first aspect of the present invention is characterized in that it further includes a delay line provided in the connection path between the plurality of combined wave filter units and the optical switch unit to adjust the delay time of the detection timing of the switching point by the monitoring unit. Video switcher. The claim is characterized in that the control unit counts a delay time based on the timing of a switching point notified from the monitoring unit, and performs switching control of the optical switch unit at a timing when a predetermined count value is reached. The video switcher according to 1. It also has a line error check unit that checks the check code included in each line of the frame output by the optical switch unit.
The claim is characterized in that the control unit changes the predetermined count value to perform switching control of the optical switch unit, and determines the predetermined count value for which error information is not notified from the line error check unit. The video switcher according to 3. It also has a line error check unit that checks the check code included in each line of the frame output by the optical switch unit.
The control unit gives a predetermined delay time to the timing of the switching point notified from the monitoring unit, changes the predetermined delay time to perform switching control of the optical switch unit, and causes an error from the line error check unit. The video switcher according to claim 1, wherein the predetermined delay time for which information is not notified is determined, and the delay time corresponding to the first half position of the switching point period is determined. The monitoring unit inputs the output signals of the optical / electric conversion unit and the optical / electric conversion unit of the electric / optical conversion unit inserted in series in the connection path between the optical link and the combined wave filter unit. The video switcher according to any one of claims 1 to 5, wherein the video switcher is characterized. The monitoring unit inputs an output signal of an optical / electrical conversion unit provided after the branch output of the light demultiplexing unit inserted in the connection path between any of the optical links and the combined wave filter unit. The video switcher according to any one of claims 1 to 5, wherein the video switcher is characterized. When the length of the connection path between the combined wave filter unit and the optical switch unit is undefined,
The monitoring unit acquires a signal having a predetermined wavelength from a wavelength drop unit inserted in the vicinity of the optical switch unit of the connection path for each video content.
The control unit detects the delay time for each video content from the timing of the switching point notified from the monitoring unit for each video content, and controls the delay line inserted after the wavelength drop unit to perform phase matching. The video switcher according to any one of claims 1 to 7, wherein the video switcher is to be performed. When the length of the connection path between the combined wave filter unit and the optical switch unit is undefined,
The monitoring unit acquires a signal having a predetermined wavelength from a wavelength drop unit inserted in the vicinity of the optical switch unit of the connection path for each video content.
The control unit detects the delay time for each video content from the timing of the switching point notified from the monitoring unit for each video content, and cancels the delay time with respect to the frame synchronizer provided for each video content. The video switcher according to any one of claims 1 to 7, wherein the video switcher is instructed to provide a delay for the purpose. A plurality of combined wave filter units that accommodate a plurality of optical links for each video content and wavelength-multiplex the signals of the plurality of optical links into one fiber for each video content.
An optical switch unit that switches and outputs an optical signal path whose wavelength is multiplexed by the plurality of combined wave filter units, and an optical switch unit.
A delay line provided in the connection path between the plurality of combined wave filter units and the optical switch unit, and
A line error check unit that checks the check code included in each line of the frame output by the optical switch unit, and a line error check unit.
It is characterized by having a control unit that receives information on the presence or absence of an error from the line error check unit, adjusts the delay line at a timing without the error, and controls switching of the optical switch unit at the timing. Video switcher. A plurality of optical links are accommodated for each video content by a plurality of combined wave filter units, and the signals of the plurality of optical links are wavelength-multiplexed on one fiber for each video content.
The monitoring unit monitors the timing of the switching point of the optical link.
Based on the timing of the switching point notified from the monitoring unit, the control unit controls the optical path switching.
A video switch method comprising switching and outputting the paths of optical signals whose wavelengths are multiplexed by the plurality of combined wave filter units by the optical switch unit in response to the optical path switching control signal from the control unit. A plurality of optical links are accommodated for each video content by a plurality of combined wave filter units, and the signals of the plurality of optical links are wavelength-multiplexed on one fiber for each video content.
The delay line delays the optical signals whose wavelengths are multiplexed by the plurality of combined wave filters.
The optical switch unit switches and outputs the path of the delayed optical signal whose wavelengths are multiplexed by the plurality of combined wave filter units.
The line error check unit checks the check code included in each line of the frame output by the optical switch unit.
A video characterized in that the control unit receives information on the presence or absence of an error from the line error check unit, adjusts the delay line at a timing without the error, and controls switching of the optical switch unit at the timing. Switch method.

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