JP2011217137A - Encoder, encoding system and signal transmission method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an encoder, an encoding system and a signal transmission method with high economic efficiency, for reducing interruption of video service.SOLUTION: An active-system encoder 1 encodes a video signal from an external device, accumulates the encoded video signal in a buffer, and transmits the video signals accumulated in the buffer. A standby-system encoder 2 receives the video signals transmitted by the active-system encoder 1, performs processing on the video signal from the external device, and selectively transmits either of the video signal transmitted by the active-system encoder or the video signal encoded by the encoder to a transmission line. Then, the active-system encoder 1 transmits the video signal encoded by the encoder to the transmission line when a fault occurs in the standby-system encoder 2. In addition, the standby-system encoder 2 transmits the video signal encoded by the encoder to the transmission line when the fault occurs in the active-system encoder 1.

Description

  The present invention relates to an encoding device, an encoding system, and a signal transmission method.

  In recent years, the broadcasting industry has shifted from analog to digital broadcasting. In line with this, high-quality video transmission services for various video materials such as news and sports broadcasts in various fields such as the field of material collection from shooting sites to broadcast stations and the field of distribution for end users, etc. There is a need to provide. Here, the high-quality video transmission service is, for example, a service represented by high-definition broadcasting.

  In addition, with the expansion of network bandwidth and price reduction, video data collection and relay using expensive dedicated lines such as conventional satellite lines, xDSL (x Digital Subscriber Line) and FTTH (Fiber To The Home) Video collection and relay using inexpensive broadband networks such as In addition, the need for high-quality video distribution services for end users using broadband networks represented by IPTV (Internet Protocol TeleVision) is rapidly increasing.

  Therefore, an IP encoder that encodes (compresses) an input video such as a camera or video content and transmits it to an IP (Internet Protocol) network is one of the important elements in recent video transmission systems.

  Video materials distributed to end users in the field of video transmission systems such as digital broadcasting are viewed directly by end users as a service. For this reason, it is not permitted that the service is interrupted or the frames are dropped due to a failure of the video transmission system. Therefore, various techniques have been proposed in order to realize reliable video transmission using an IP encoder. For example, in video distribution from a base that provides video services via an IP network (hereinafter sometimes referred to as “IPTV headend”) to a subscriber (end user) of an IPTV service, N + 1 Generally, a redundant configuration is adopted. In addition, it is common to adopt a 1: 1 redundancy configuration for collecting and relaying materials between broadcasting stations such as the branch office and the main station.

  In the case of the N + 1 redundant configuration, N active IP encoders, one standby IP encoder, and an NMS (Network Management System) that monitors each IP encoder are configured. The working IP encoder is an encoder that performs processing in a normal state. The standby encoder is an encoder that does not perform processing in a normal state and switches from the active IP encoder to take over the processing performed by the active IP encoder when a failure occurs in the active IP encoder. When a failure occurs in the active IP encoder, the active IP encoder transmits an alarm signal to the NMS using an SNMP (Simple Network Management Protocol) trap signal or the like. The NMS receives this SNMP trap signal, detects the failure of the IP encoder, and secures redundancy by controlling the MatrixSW (SWitcher) and network devices, etc. arranged in the preceding and succeeding IP encoders. Yes.

  FIG. 16 is a diagram for explaining a conventional N + 1 redundant configuration. Each of ENC # 1 to ENC # n is one IP encoder. ENC # 1 to ENC # n-1 are active IP encoders. ENC # n is a standby IP encoder. ENC # 1 to ENC # n-1 are collectively referred to as IP encoder 902. The solid line indicates the path of the video signal, and the dotted line indicates the path of the management signal. This management signal path includes a Management LAN (Local Aria network) 907. The video equipment 906 inputs video to the IP encoder 902 via the MatrixSW 903. The IP encoder 902 performs an encoding process on the input video. Then, the IP encoder 902 transmits the encoded video to the IP network. Next, a case where a failure occurs will be described. For example, when a failure occurs in ENC # 3, ENC # 3 transmits an SNMP trap to NMS 901 via ManagementLAN 907. The NMS 901 detects that a failure has occurred in ENC # 3 by receiving an SNMP trap from ENC # 3. Next, the NMS 901 outputs a control signal to the ENC # n via the ManagementLAN 907, and causes the ENC # n to read the setting information of the ENC # 3. Then, the NMS 901 performs switching control to ENC # n by a control signal passed through the ManagementLAN 907. In addition, the NMS 901 controls the Matrix SW 903 to switch the video output to ENC # 3 to ENC # n by a control signal that has passed through the ManagementLAN 907, and avoids sending unnecessary data as necessary. Shut down the output port of ENC # 3 in the fault state. Here, the NMS 901 may suppress sending of unnecessary data by controlling the new power port of the SW 904 or the router 905 to which ENC # 3 is connected.

  On the other hand, the 1: 1 redundant configuration can be divided into a case where a single device has a redundant configuration and a case where a plurality of devices form a redundant configuration.

  If there is a 1: 1 redundant configuration inside a single device, all the units that perform video processing such as video input, transmission unit, reception unit, and video output unit are duplicated in a single housing. It has been broken.

  FIG. 17 is a diagram for explaining a 1: 1 redundant configuration inside one conventional apparatus. Here, in the IP encoder 910, the signal input unit 912, the transmission unit 914, and the power supply unit 916 are duplexed, and the signal input unit 913, the transmission unit 915, and the power supply unit 917 are duplexed as a standby system. The power supply unit 916 and the power supply unit 917 supply power to each unit surrounded by a one-dot chain line 919. The control unit 911 monitors and controls each unit surrounded by a dotted line 918. In a state where no failure has occurred, the IP encoder 910 sends the video from the video equipment 920 to the transmission path via the signal input unit 912 and the transmission unit 914. Then, the control unit 911 switches to the signal input unit 913 when the signal input unit 912 fails. The control unit 911 switches to the transmission unit 915 when a failure occurs in the transmission unit 914. In addition, when a failure occurs in the power supply unit 916, the control unit 911 switches to the power supply unit 917. For example, when a failure occurs in the signal input unit 912, the IP encoder 910 sends the video from the video equipment 920 to the transmission path via the signal input unit 913 and the transmission unit 914. As described above, when a 1: 1 redundant configuration is provided within one apparatus, switching processing is performed within the casing of the apparatus.

  FIG. 18 is a diagram for explaining a 1: 1 redundant configuration in a plurality of conventional devices. Here, the IP encoder 930 is a working IP encoder, and the IP encoder 940 is made redundant as a standby IP encoder. The IP encoder 930 includes a signal input unit 931, a transmission unit 932, and a control unit 933. The IP encoder 940 includes a signal input unit 941, a transmission unit 942, and a control unit 943. When a failure occurs in the signal input unit 931 and the signal input unit 941, the control unit 933 detects the failure and notifies the NMS 950 of the failure using SNMP trap or the like. In response to the notification from the control unit 933, the NMS 950 switches the signal path from the IP encoder 930 to the IP encoder 940.

JP 2009-17508 A

  However, the conventional IP encoder switching operation method using the N + 1 redundant configuration has the following problems.

  First, the NMS that performs switching control normally holds the setting information of all IP encoders. To perform switching control from the active IP encoder to the standby IP encoder after a failure occurs, the NMS uses SNMP trap. After reception, the setting information of the faulty device is read by the standby IP encoder to perform switching, so that switching of the system takes time, and as a result, the video service may be interrupted.

  In addition, the SNMP trap packet that the IP encoder sends to the NMS when a failure occurs is in the UDP (User Datagram Protocol) format, especially when it is sent using the same transmission path as the video data because of congestion due to video traffic. The NMS may not be reached. Even if an independent monitoring LAN is constructed, there may be a case where the SMNP trap packet cannot be transmitted to the NMS due to a monitoring LAN link failure or a failure of the IP encoder device itself. In order to cope with such a situation, it is conceivable to perform polling monitoring (for example, Internet Control Message Protocol (ICMP) or SNMP polling) by NMS. However, even if polling monitoring is used, there still remains a problem that a link failure that requires encoder switching cannot be detected promptly. Therefore, due to these reasons, it takes time to switch the system, and as a result, the video service may be interrupted.

  In addition, the IP encoder switching operation method based on the 1: 1 redundancy configuration has the following problems.

  In particular, in the case of a 1: 1 redundant configuration inside one apparatus, it is necessary to duplicate all the parts in the apparatus casing, resulting in an increase in circuit scale and high manufacturing and operation costs.

  In addition, in the case of a 1: 1 redundancy configuration with a plurality of devices, an NMS or the like is required for switching control. For this reason, it is necessary to perform switching control under the initiative of the NMS, and it is necessary to identify the fault location and perform encoding and transmission in the standby system from that location. Therefore, the video service may be interrupted by switching the IP encoder.

  The disclosed technique has been made in view of the above, and an object thereof is to provide an economically efficient encoding apparatus, encoding system, and signal transmission method that reduce the occurrence of interruption of video services.

  An encoding device, an encoding system, and a signal transmission method disclosed in the present application are, in one aspect, encoding a video signal from an external device and storing the encoded video signal in a buffer and storing the encoded video signal in the buffer. A first encoding unit that transmits the received video signal, and the video signal transmitted from the first encoding unit, the video signal from the external device being processed, and the first encoding unit A second encoding unit that selectively sends out either a video signal obtained by adding a delay of a predetermined time to the video signal transmitted by the video signal or a video signal encoded by itself to the transmission path, and the first encoding unit. Transmits a video signal encoded by itself to the transmission line when a failure occurs in the second encoding unit, and the second encoding unit generates a failure in the first encoding unit. If the self-encoded video And it sends to the transmission line items.

  According to one aspect of the encoding device, the encoding system, and the signal transmission method disclosed in the present application, it is possible to reduce the occurrence of interruption of the video service while suppressing the manufacturing cost.

FIG. 1 is a block diagram of an encoding system according to the first embodiment. FIG. 2 is a block diagram of an encoding system according to the second embodiment. FIG. 3 is a diagram for explaining the transmission confirmation packet and the control packet. FIG. 4 is a diagram for explaining a switching process when an active system failure occurs. FIG. 5 is a diagram for explaining the flow of a video stream in switching when an active system failure occurs. FIG. 6 is a diagram for explaining switching processing when a standby system fails. FIG. 7 is a diagram for explaining the flow of a video stream in switching when a standby system failure occurs. FIG. 8 is a sequence diagram when a failure occurs in the working encoder. FIG. 9 is a sequence diagram when a failure occurs in the standby encoder. FIG. 10 is a block diagram of an encoding system according to the third embodiment. FIG. 11 is a diagram for explaining the switch-back process when an active system failure occurs. FIG. 12 is a diagram for explaining switch-back processing when a standby system failure occurs. FIG. 13 is a sequence diagram of switchback processing when a failure occurs in the working encoder. FIG. 14 is a sequence diagram of switch-back processing when a failure occurs in the standby encoder. FIG. 15 is a system configuration diagram when an NMS is added. FIG. 16 is a diagram for explaining a conventional N + 1 redundant configuration. FIG. 17 is a diagram for explaining a conventional 1: 1 redundant configuration inside one apparatus. FIG. 18 is a diagram for explaining a 1: 1 redundant configuration in a plurality of conventional devices.

  Embodiments of an encoding device, an encoding system, and a signal transmission method disclosed in the present application will be described below in detail with reference to the drawings. The following embodiments do not limit the encoding device, the encoding system, and the signal transmission method disclosed in the present application.

  FIG. 1 is a block diagram of an encoding system according to the first embodiment. The encoding system according to the present embodiment includes an active encoding device 1 and a standby encoding device 2. This working encoding device 1 is an example of a first encoding device. The standby encoding device 2 is an example of a second encoding device.

  As shown in FIG. 1, the working encoding apparatus 1 includes a second transmission buffer 11, a transmission unit 12, and a data processing unit 16.

  The data processing unit 16 receives an input of a video signal from an external device. The data processing unit 16 performs an encoding process on the video signal. Then, the data processing unit 16 outputs the encoded video signal to the second transmission buffer 11.

  The second transmission buffer 11 is a storage device such as a memory. The second transmission buffer 11 receives a video signal input from the data processing unit 16. Then, the second transmission buffer 11 accumulates the video signal input from the data processing unit 16.

  The transmission unit 12 reads out the video signal stored in the second transmission buffer 11, and transmits the video signal read out toward the data processing unit 16 toward the reception unit 23 of the standby system encoding device 2 to be described later. Will be sent out sequentially. The transmission unit 12 transmits the read video signal to the end user via the transmission path 3 when a failure occurs in the standby encoding device 2.

  As shown in FIG. 1, the standby coding apparatus 2 includes a second transmission buffer 21, a transmission unit 22, a reception unit 23, and a data processing unit 26.

  The receiving unit 23 receives the video signal output from the transmitting unit 12 of the active encoding device 1 via the transmission path 3. Then, the reception unit 23 outputs the video signal received from the transmission unit 12 to the second transmission buffer 21. However, if a failure occurs in the active encoding device 1 and the video signal from the transmission unit 12 cannot be received, the reception unit 23 cannot output the video signal to the second transmission buffer 21. Hereinafter, the fact that the video signal cannot be received may be referred to as “video signal not received”.

  The data processing unit 26 performs an encoding process on the video signal input from the external device. Here, the external device in which the data processing unit 26 receives the input of the video signal is the same device as the external device in which the data processing unit 16 receives the input of the video signal. Then, the data processing unit 26 outputs the processed video signal to the second transmission buffer 21.

  The second transmission buffer 21 is a storage device such as a memory. The second transmission buffer 21 receives a video signal input from the data processing unit 26. The data processing unit 26 accumulates the video signal input from the data processing unit 26.

  The transmitter 22 reads the video signal received by the receiver 23 when the receiver 23 receives the data transmitted by the transmitter 12. Then, the transmission unit 22 gives a delay of a predetermined time to the video signal read from the first transmission buffer 24 and sequentially sends it to the transmission path 3.

  In addition, the transmission unit 22 stores the video signal received by the reception unit 23 and the second transmission buffer 21 so that the video signal is continuous when a failure occurs in the active encoding device 1. Read video signal. Then, the transmission unit 22 sequentially transmits the read video signal to the transmission path 3. The data transmitted from the transmission unit 22 is transmitted to the end user.

  As described above, the encoding system according to the present embodiment transmits the video signal encoded by the active system from the standby system to the transmission path in a state where no failure occurs in the active system. When a failure occurs in the active system, the encoding system according to the present embodiment encodes the video signal in the standby system and stores it in the second transmission buffer, and then the first transmission buffer and the second transmission buffer. The data stored in the transmission buffer is connected and transmitted. When a failure occurs in the standby system, the video signal encoded in the active system is transmitted as it is from the active system.

  That is, the encoding system according to the present embodiment arranges the active encoding device and the standby encoding device in series, and when a failure occurs in either of them, a video that bypasses the device in which the failure has occurred is displayed. Send a signal. Thus, the encoding system according to the present embodiment can be switched by the own apparatus. In other words, there is no need for switching control by NMS or the like. For this reason, it takes no time to notify the occurrence of a failure to an external device such as an NMS and to receive a control command. As a result, even if switching to the standby system occurs, data can be continuously transmitted without causing missing data such as dropped frames. Therefore, it is possible to reduce the occurrence of interruption of the video service.

  Further, as in the present embodiment, the active system encoding apparatus and the standby system encoding apparatus are arranged in series, so that the circuit scale in the same apparatus can be reduced and the cost can be reduced.

  FIG. 2 is a block diagram of an encoding system according to the second embodiment. The encoding system according to the present embodiment includes an active encoder 1 and a standby encoder 2. The working encoder 1 is an example of a “first encoding device”. The standby encoder 2 is an example of a “second encoding device”. Both the active encoder 1 and the standby encoder 2 receive the video stream from the broadcast station 4. Here, in this embodiment, the active encoder 1 and the standby encoder 2 receive the video material captured by the video equipment from the broadcast station 4 as a video stream. You may receive a video stream. The working encoder 1 and the standby encoder 2 are IPTV head ends. The active encoder 1 and the standby encoder 2 are connected via a transmission path 3. The active encoder 1 and the standby encoder 2 can exchange data with each other. However, in the following, for the sake of explanation, the transmission path 3 may be omitted in data exchange between the active encoder 1 and the standby encoder 2.

  In the following description, an encoder failure refers to a state in which a video stream cannot be transmitted from the encoder.

  As shown in FIG. 2, the working encoder 1 includes a second transmission buffer 11, a transmission unit 12, a reception unit 13, a first transmission buffer 14, a control unit 17, a network interface 18, a signal input unit 161, and an encoding unit. Part 162. The standby encoder 2 includes a second transmission buffer 21, a transmission unit 22, a reception unit 23, a first transmission buffer 24, an interruption position specifying unit 25, a control unit 27, a network interface 28, a signal input unit 261, a code And a receiving buffer 29.

  First, the working encoder 1 will be described. The network interface 18 is an interface that mediates data transfer between the transmission path 3 and each unit of the working encoder 1. Actually, data is exchanged between each part of the working encoder 1 and the transmission path 3 via the network interface 18, but in the following, for the sake of explanation, data is exchanged between the transmission path 3 and the working encoder 1. The network interface 18 may be omitted for explanation.

  The signal input unit 161 receives an input of a video stream transmitted from the broadcast station 4. Then, the signal input unit 161 outputs the video stream to the encoding unit 162.

  The encoding unit 162 receives an input of a video stream from the signal input unit 161. Then, the encoding unit 162 performs an encoding process on the video stream. In the present embodiment, the encoding unit 162 performs a compression process on the video stream as one of the encoding processes, for example. In this embodiment, the compressed data of the video stream that has been subjected to the encoding process includes the sequence number of the video stream. Hereinafter, the video stream that has been subjected to the encoding process may be simply referred to as a “video stream”. The encoding unit 162 outputs the video stream to the transmission buffer 11. The signal input unit 161 and the encoding unit 162 are examples of the “first processing unit”.

  The second transmission buffer 11 is an information storage device such as a memory. Then, the second transmission buffer 11 accumulates the video stream input from the encoding unit 162. Here, when the video stream stored in the second transmission buffer 11 is transmitted to the end user via the reception unit 23 or the transmission path 3, the transmission unit 12 described later transmits the transmitted video stream. The video stream corresponding to is deleted. In this manner, the video stream is accumulated in the second transmission buffer 11 for a certain period of time.

  The reception unit 13 receives a transmission confirmation packet from the transmission confirmation notification unit 271 before the failure of the standby encoder 2 occurs. Then, the reception unit 13 outputs a reception notification of the transmission confirmation packet to the control unit 17. This reception notification includes video stream identification information such as a sequence number. The receiving unit 13 is an example of an “information receiving unit”.

  Here, the structure of the transmission confirmation packet will be described. FIG. 3 is a diagram for explaining the transmission confirmation packet and the control packet. As shown in FIG. 3, the transmission confirmation packet has areas such as an address field 301, a transmission confirmation / control field 302, and a data area 303. An example of information included in each area is described in the lower part of each area in FIG. The address field 301 includes a transmission destination address and a transmission source address. The destination address may be a multicast address or a unicast address. In the transmission confirmation / control field 302 of the transmission confirmation packet, the transmission confirmation packet from the standby encoder 2 to the active encoder 1 includes, for example, transmission confirmation information. The transmission confirmation packet from the standby encoder 2 to the active encoder 1 includes a sequence number in the data area. The active encoder 1 can grasp that transmission of the video stream having the sequence number described in the data area 303 has been completed by transmitting such a transmission confirmation packet.

  The first transmission buffer 14 is an information storage device such as a memory. When there is no failure in the working encoder 1, the first transmission buffer 14 rewrites and stores the transmission destination address of the video stream transmitted from the transmission unit 12 to the reception unit 23 to the address for the end user. I will do it. As will be described later, the video stream stored in the first transmission buffer 14 is deleted by the control unit 17 after the reception unit 13 receives the transmission confirmation packet. Then, after the failure of the active encoder 1, the first transmission buffer 14 accumulates the video stream input from the reception buffer 19. A video stream is accumulated in the first transmission buffer 11 for a predetermined time.

  Next, the transmission unit 12 will be described. The transmission unit 12 is configured such that when there is no failure in the active encoder 1 and the standby encoder 2, when the failure occurs in the active encoder 1, The operation is different when a failure occurs in the encoder 2. Therefore, in the following, explanation will be made by dividing into cases.

  First, a case where no failure has occurred in either the working encoder 1 or the standby encoder 2 will be described. The transmission unit 12 reads the video stream stored in the second transmission buffer 11. Then, the transmission unit 12 transmits the read video stream to the reception unit 23 of the standby encoder 2. Here, the video stream transmitted from the transmission unit 12 to the reception unit 23 is not transmitted to the end user via the transmission path 3 because the standby encoder 2 is designated as the transmission destination address. In this embodiment, the transmission path 3 is used for communication between the active encoder 1 and the standby encoder 2 in order to reduce the cost. However, a dedicated line may be used.

  Next, a case where a failure occurs in the working encoder 1 will be described. The transmission unit 12 cannot send the signal to the reception unit 23 of the standby encoder 2 because a failure has occurred in the active encoder 1. Therefore, the transmission unit 12 does not transmit the video stream and enters a standby state.

  Next, a case where a failure occurs in the standby encoder 2 will be described. The transmission unit 12 receives from the control unit 17 a transmission command to the end user of the video stream. Then, the transmission unit 12 reads the video stream accumulated in the first transmission buffer 14. Here, the transmission destination address of the video stream stored in the first transmission buffer 14 is the end user. Therefore, the transmission unit 12 transmits the video stream read from the first transmission buffer 14 to the end user.

  Here, the transmission of the video stream by the transmission unit 12 is performed using, for example, a control packet as shown in FIG. In this case, the address of the standby encoder 2 is described in the address field of the control packet. The transmission confirmation / control field 302 includes information on transmission of the video stream. Further, the data area 303 includes a video stream. This video stream is encoded and includes a sequence number and the like.

  Next, the control unit 17 will be described. The control unit 17 is configured such that when no failure occurs in either the active encoder 1 and the standby encoder 2, or when a failure occurs in the active encoder 1, the standby unit The operation is different when a failure occurs in the encoder 2. Therefore, in the following, explanation will be made by dividing into cases. The control unit 17 is an example of a “first control unit”.

  First, a case where no failure has occurred in either the working encoder 1 or the standby encoder 2 will be described. When receiving a transmission confirmation packet from a transmission confirmation notifying unit 271 of the standby encoder 2 to be described later, the control unit 17 deletes the corresponding video stream for which the transmission confirmation has been stored in the first transmission buffer 14.

  Next, a case where a failure occurs in the working encoder 1 will be described. The control unit 17 ignores the transmission confirmation packet reception notification from the reception unit 13. In addition, the active encoder 1 cannot transmit the video stream due to a failure, but the video stream may be later restored to a delayed state. However, it is not preferable that the video stream is transmitted from the active encoder 1 after switching to the standby encoder 2. Therefore, the control unit 17 controls the transmission unit 12 so as not to transmit data.

  Next, a case where a failure occurs in the standby encoder 2 will be described. The control unit 17 receives a notification from the reception unit 13 that the transmission confirmation packet is not received from the control unit 27. And the control part 17 specifies the flame | frame corresponding to the transmission confirmation packet received at the end. Then, the control unit 17 reads the video stream from the frame next to the frame corresponding to the last received transmission confirmation packet from the first transmission buffer 14 and transmits the read video stream to the end user. 12 is controlled.

  Next, the standby encoder 2 will be described. The network interface 28 is an interface that mediates data transfer between the transmission path 3 and each unit of the standby encoder 2. Actually, data is exchanged between each part of the standby encoder 2 and the transmission path 3 via the network interface 28. However, for the sake of explanation, the data transmission between the standby encoder 2 and the transmission path 3 will be described below. Data exchange may be described with the network interface 28 omitted.

  The signal input unit 261 receives an input of a video stream transmitted from the broadcast station 4. Then, the signal input unit 261 outputs the video stream to the encoding unit 262.

  The encoding unit 262 receives a video stream input from the signal input unit 261. Then, the encoding unit 262 discards the received video stream when there is no failure in the working encoder 1. On the other hand, when a failure occurs in the working encoder 1, the encoding unit 262 receives an encoding effective command from the control unit 17, and performs an encoding process on the video stream. Then, the encoding unit 262 outputs the video stream to the second transmission buffer 21. Here, in the present embodiment, the encoding unit 262 does not perform encoding when there is no failure in the working encoder 1. However, even when there is no failure in the working encoder 1, the encoding unit 262 may perform encoding. The signal input unit 261 and the encoding unit 262 are examples of a “second processing unit”.

  The second transmission buffer 21 is an information storage device such as a memory. The transmission buffer 21 accumulates the video stream input from the encoding unit 262 when a failure occurs in the active encoder 1. Among the video streams stored in the encoding unit 262, those that match the video stream transmitted to the end user by the transmission unit 22 described later are deleted.

  Next, the receiving unit 23 will be described. In the receiving unit 23, when there is no failure in the working encoder 1 and the standby encoder 2, the receiving unit 23 has a standby system when a failure occurs in the working encoder 1. The operation is different when a failure occurs in the encoder 2. Therefore, in the following, explanation will be made by dividing into cases.

  First, a case where no failure has occurred in either the working encoder 1 or the standby encoder 2 will be described. The receiving unit 23 receives the video stream transmitted from the transmitting unit 12. Then, the reception unit 23 outputs the video stream to the reception buffer 29. Further, the receiving unit 23 notifies the control unit 27 that the video stream has been received from the active encoder 1.

  Next, a case where the working encoder 1 fails will be described. The reception unit 23 cannot receive the video stream from the transmission unit 12. Therefore, the receiving unit 23 notifies the control unit 27 that the video stream from the active encoder 1 cannot be received.

  Next, a case where the standby encoder 2 fails will be described. In this case, since the input of the video stream from the transmission unit 12 is stopped, the reception unit 23 is in a standby state.

  The reception buffer 29 is an information storage device such as a memory. The reception buffer 29 stores and accumulates the video stream input from the reception unit 23. However, when the input of the video stream from the receiving unit 23 is stopped, the video stream is not accumulated in the reception buffer 29, so that the video stream until the stop is accumulated in the reception buffer. The reception buffer 29 converts the transmission destination address of the stored video stream into an address for the end user, and outputs the converted address to the first transmission buffer 24.

  The first transmission buffer 24 is an information storage device such as a memory. The first transmission buffer 24 receives the input of the video stream encoded by the working encoder 1 from the reception buffer 29. Then, the first transmission buffer 24 accumulates the video stream encoded by the working encoder 1.

  Next, the transmission unit 22 will be described. The transmission unit 22 is configured such that when no failure occurs in either the active encoder 1 and the standby encoder 2, or when the failure occurs in the active encoder 1, the standby unit 22 The operation is different when a failure occurs in the encoder 2. Therefore, in the following, explanation will be made by dividing into cases.

  First, a case where no failure has occurred in either the working encoder 1 or the standby encoder 2 will be described. The transmission unit 22 reads the video stream stored in the first transmission buffer 24. Here, the transmission destination address of the video stream stored in the first transmission buffer 24 is for the end user. Therefore, the transmission unit 22 transmits the video stream read from the first transmission buffer 24 to the end user. Here, the transmission unit 22 reads a video stream from the first transmission buffer 24 and gives a delay of a predetermined time to the output of the working encoder 1 when transmitting the video stream to the end user. In the present embodiment, it is assumed that the transmission unit 22 gives a delay of a predetermined time of 170 ms. In this embodiment, 170 ms corresponds to the time for five video streams (5 frames). That is, in this embodiment, a delay is given to the video stream output from the working encoder 1 by the first transmission buffer 24, and the video stream output from the transmitting unit 22 is 170 ms after the timing output from the working encoder 1. Will be.

  The transmission unit 22 transmits a transmission confirmation packet of the video stream transmitted to the end user to the control unit 17 of the working encoder 1. The transmission confirmation packet includes video stream identification information such as a video stream sequence number.

  Next, a case where a failure occurs in the working encoder 1 will be described. The transmission unit 22 reads the video stream from the first transmission buffer 24. Then, the transmission unit 22 transmits the read video stream to the end user via the transmission path 3. Here, as will be described later, the video stream in which the video streams stored in the second transmission buffer 21 are connected so that the data continues from the interruption position of the video stream due to the occurrence of the failure is the first transmission buffer. 21 is accumulated. For this reason, the video stream transmitted by the transmission unit 22 is a continuous video stream without interruption.

  Next, a case where a failure occurs in the standby encoder 2 will be described. When the video stream cannot be transmitted, the transmission unit 22 stops transmitting the transmission confirmation packet to the reception unit 13 of the active encoder 1.

  When a failure occurs in the working encoder 1, the interruption position specifying unit 25 is a video stream stored in the second transmission buffer 21 and a video stream stored in the first transmission buffer 24. A command for specifying a matching position is received from the control unit 27. Then, the interruption position specifying unit 25 compares the video stream stored in the second transmission buffer 21 with the video stream stored in the first transmission buffer 24. For example, the interruption position specifying unit 25 specifies the check point immediately before the interruption position included in the video stream stored in the first transmission buffer 24. Then, the interruption position specifying unit 25 specifies the check point at the same position in the video stream stored in the second transmission buffer 21. Then, the interruption position specifying unit 25 sequentially checks the video stream accumulated in the first transmission buffer 24 and the video stream accumulated in the second transmission buffer 21 from the check point. Thereby, the interruption position specifying unit 25 specifies the position of the video stream in the second transmission buffer 21 corresponding to the position where the video stream in the first transmission buffer 24 is interrupted. Then, the interrupt position specifying unit 25 outputs the specified position in the video stream of the second transmission buffer 21 and the interrupted position of the video stream stored in the first transmission buffer 24 to the control unit 27.

  Next, the control unit 27 will be described. The control unit 27 is configured such that when no failure occurs in either the active encoder 1 and the standby encoder 2, or when a failure occurs in the active encoder 1, the standby unit The operation is different when a failure occurs in the encoder 2. Therefore, in the following, explanation will be made by dividing into cases.

  First, a case where no failure has occurred in either the working encoder 1 or the standby encoder 2 will be described. The control unit 27 receives a notification from the receiving unit 23 that the video stream has been received from the active encoder 1. In this case, the control unit 27 reads the video stream input from the active encoder 1 from the first transmission buffer 24 and controls the transmission unit 22 so as to maintain the state of sending to the end user.

  Next, a case where a failure occurs in the standby encoder 2 will be described. The control unit 27 receives a notification from the reception unit 23 that the video stream from the standby encoder 2 cannot be received. Then, the control unit 27 specifies an interrupt position specifying command for specifying a position in the video stream stored in the second transmission buffer 21 that matches the interrupt position of the video stream stored in the first transmission buffer 24. To the unit 25. Then, the control unit 27 receives the input of the specified position in the video stream of the second transmission buffer 21 and the interrupted position of the video stream stored in the first transmission buffer 24 from the interruption position specifying unit 25. The control unit 27 transfers the video stream stored in the second transmission buffer 21 to the first transmission buffer 24 so that the video stream is continuous with the video stream stored in the first transmission buffer 24. . For example, the control unit 27 reads the video stream after the interruption position of the video stream stored in the first transmission buffer 24 from the video stream of the second transmission buffer 21 and stores it in the first transmission buffer 24. Forward. Then, the control unit 27 changes the transmission destination address of the video stream stored in the second transmission buffer 21 for the end user. As a result, the control unit 27 can connect the video stream stored in the first transmission buffer 24 and the video stream stored in the second transmission buffer 21 so as to be continuous. Then, the control unit 27 controls the transmission unit 22 to transmit the video stream stored in the first transmission buffer 24 toward the end user. Here, since the transmission unit 22 gives a delay of a predetermined time to the video stream, the video stream stored in the second transmission buffer 21 corresponds to the video stream received from the transmission unit 12 of the active encoder 1. Thus, a video stream of a predetermined time remains. Therefore, there is a predetermined time before the interruption position, and during that time, the interruption position can be specified and the video signals can be connected.

  Next, a case where a failure occurs in the standby encoder 2 will be described. When the video stream cannot be output from the transmission unit 22, the control unit 27 stops the transmission confirmation packet transmitted to the control unit 17 by the transmission confirmation notification unit 271. In addition, even when the transmission confirmation packet cannot be transmitted from the control unit 27 due to a failure, the transmission confirmation notification unit 271 stops transmitting the transmission confirmation packet.

  Next, referring to FIG. 4, the overall processing flow of switching when an active system failure occurs will be described. Here, FIG. 4 is a diagram for explaining the switching process when the active system failure occurs.

  As shown in FIG. 4, the information transmission system according to the present embodiment actually includes a Matrix SW 5, a switch 6, and a router 7. Here, it is assumed that n encoders are arranged. The active encoder 1 and the standby encoder 2 are combined as a redundant configuration. In FIG. 4, for easy understanding, the solid line arrows indicate the data flow before the occurrence of the failure, and the dotted line arrows indicate the data flow after the occurrence of the failure.

  Before a failure occurs in the active encoder 1, the video stream transmitted from the broadcast station 4 is input to the active encoder 1 via the Matrix SW 5 (step S101). Then, the video stream is transmitted from the active encoder 1 to the standby encoder 2 (step S102). Then, a transmission confirmation packet is transmitted from the standby encoder 2 to the active encoder 1 (step S103). Then, the standby encoder 2 transmits the video stream to the end user via the IP network via the switch 6 and the router 7 (step S104).

  When a failure occurs in the working encoder 1, the data flow in step S102 of the data flow before the failure is stopped. Therefore, when the video stream cannot be received in step S102, switching to the standby encoder 2 is performed. The process is as follows. That is, the standby encoder 2 receives the video stream transmitted from the broadcast station 4 (step S201). Then, standby encoder 2 transmits the video stream to the end user via the IP network via switch 6 and router 7 (step S202).

  Next, with reference to FIG. 5, the flow of the video stream in switching when the active system failure occurs will be described. Here, FIG. 5 is a diagram for explaining the flow of the video stream in switching when the active system failure occurs. In the active encoder 1 and the standby encoder 2 in FIG. 5, in order to make the description easy to understand, each part not necessary for the following description is omitted. Furthermore, in FIG. 5, the solid line arrows represent the flow of the video stream before switching, and the dotted line arrows represent the flow of the video stream after switching.

  First, the flow of the video stream before switching will be described. The signal input unit 161 receives an input of a video stream (step S301). Then, the video stream is input from the signal input unit 161 to the encoding unit 162 (step S302), and the encoding unit 162 performs encoding such as compression. Then, the video stream is input from the encoding unit 162 to the second transmission buffer 11 (step S303). Then, the transmission unit 12 reads the video stream from the second transmission buffer 11 (step S304), and transmits it to the reception unit 23 (step S305). Then, the video stream is input from the receiving unit 23 to the first transmission buffer 24 (step S306). Then, the video stream stored in the first transmission buffer 24 is transferred to the second transmission buffer 21 (step S307). Then, the transmission unit 22 reads the video stream from the second transmission buffer 21 (step S308), and transmits the video stream to the end user via the transmission path (step S309).

  Next, the flow of the video stream after switching will be described. The signal input unit 261 receives an input of a video stream (step S401). Then, the video stream is input from the signal input unit 261 to the encoding unit 262 (step S402), and the encoding unit 262 performs encoding such as compression. Then, the video stream is input from the encoding unit 262 to the second transmission buffer 21 (step S403). Then, the transmission unit 22 reads the video stream from the second transmission buffer 21 (step S404), and transmits the video stream to the end user via the transmission path (step S405).

  Thus, the working encoder 1 and the standby encoder 2 are arranged in series, and the video stream encoded by the working encoder 1 is transmitted via the standby encoder 2 before the failure of the working system occurs. Sent to the road. Then, after switching due to the occurrence of a failure in the active system, the video stream is directly input to the standby encoder 2, and the video stream is encoded by the standby encoder 2, and then the video stream is sent to the transmission path. .

  Next, an overall processing flow of switching when a standby system failure occurs will be described with reference to FIG. Here, FIG. 6 is a diagram for explaining switching processing when a standby system failure occurs.

  In FIG. 6, for easy understanding, the solid line arrows indicate the flow of data before the occurrence of the failure, and the dotted arrows indicate the flow of data after the occurrence of the failure.

  The process flow before the failure occurs in the standby encoder 2 is the same as the process flow before the failure occurs in the active encoder 1 shown in FIG. 4 and is represented by steps S101 to S104.

  Next, a case where a failure occurs in the standby encoder 2 will be described. In this case, transmission of the transmission confirmation packet in step S103 is stopped in the data flow before the occurrence of the failure. Therefore, when it becomes impossible to receive the transmission confirmation packet in step S103, switching to transmission of the video stream by the working encoder 1 is performed. The processing in this case is as follows. That is, the working encoder 1 receives the video stream transmitted from the broadcast station 4 (step S401). Then, the active encoder 1 transmits the video stream to the end user via the IP network via the switch 6 and the router 7 (step S402).

  Next, the flow of a video stream in switching when a standby system failure occurs will be described with reference to FIG. Here, FIG. 7 is a diagram for explaining the flow of a video stream in switching when a standby system failure occurs. In the active encoder 1 and the standby encoder 2 shown in FIG. 7, in order to make the description easy to understand, each part unnecessary for the following description is omitted. Furthermore, in FIG. 7, the solid line arrows represent the flow of the video stream before switching, and the dotted line arrows represent the flow of the video stream after switching.

  The flow of the video stream before switching is the same as the flow before a failure occurs in the working encoder 1 shown in FIG. 5, and is represented by steps S301 to S309.

  Next, the flow of the video stream after switching will be described. The signal input unit 161 receives an input of a video stream (step S501). Then, the video stream is input from the signal input unit 161 to the encoding unit 162 (step S502), and the encoding unit 162 performs encoding such as compression. Then, the video stream is input from the encoding unit 162 to the second transmission buffer 11 (step S503). Then, the transmission unit 12 reads the video stream from the second transmission buffer 11 (step S504), and transmits the video stream to the end user via the transmission path (step S505).

  Thus, the working encoder 1 and the standby encoder 2 are arranged in series, and the video stream encoded by the working encoder 1 is transmitted via the standby encoder 2 before the failure of the working system occurs. Sent to the road. Then, after switching due to the occurrence of the working system failure, the video stream is input to the working system encoder 1, encoded by the working system encoder 1, and then sent from the working system encoder 1 to the transmission path.

  Furthermore, with reference to FIG. 8, the flow of processing when a failure occurs in the working encoder 1 will be described. FIG. 8 is a sequence diagram when a failure occurs in the working encoder. Each vertical axis in FIG. 8 represents the passage of time downward as viewed in the drawing.

  The working encoder 1 stores the encoded video stream in the second transmission buffer 14 (step S601). Then, the working encoder 1 transmits the video stream to the standby encoder 2 (step S602). Furthermore, the working encoder 1 transfers the video stream stored in the second transmission buffer 14 to the first transmission buffer 11 and holds it in the second transmission buffer 14 (step S603). The standby encoder 2 accumulates the video stream received from the active encoder 1 in the first transmission buffer 24 (step S604). Then, the standby encoder 2 sends the video stream encoded by the active encoder 1 stored in the first transmission buffer 24 toward the transmission path 3 (step S605). Then, the standby encoder 2 transmits a transmission confirmation packet of the transmitted video stream to the active encoder 1 (step S606).

  Until a failure occurs, step S601 to step S606 are repeated.

  Here, when a failure occurs in the working encoder 1 (step S607), the working encoder 1 stops transmission of the video stream (step S608).

  Then, the standby encoder 2 detects the occurrence of a failure in the active encoder 1 triggered by the non-reception of the video stream from the active encoder 1 (step S609).

  Then, standby encoder 2 starts the encoding process for the video stream, and accumulates the encoded video stream in second transmission buffer 24 (step S610).

  Then, standby encoder 2 compares the video stream stored in first transmission buffer 24 in step S604 with the video stream stored in second transmission buffer 21 in step S610. Then, the standby encoder 2 identifies the interruption position, and connects the video stream stored in the first transmission buffer 24 and the video stream stored in the second transmission buffer 21 (step S611).

  Then, standby encoder 2 sends the video stream encoded by its own device toward transmission path 3 (step S612).

  Furthermore, with reference to FIG. 9, the flow of processing when a failure occurs in the standby encoder 2 will be described. FIG. 9 is a sequence diagram when a failure occurs in the standby encoder. Each vertical axis | shaft of FIG. 9 shows progress of time on the lower side toward the paper surface.

  The working encoder 1 stores the encoded video stream in the second transmission buffer 14 (step S701). Then, the working encoder 1 transmits the video stream to the standby encoder 2 (step S702). Furthermore, the working encoder 1 transfers the video stream stored in the second transmission buffer 14 to the first transmission buffer 11 and holds it in the second transmission buffer 14 (step S703). The standby encoder 2 accumulates the video stream received from the active encoder 1 in the first transmission buffer 24 (step S704). Then, the standby encoder 2 sends the video stream encoded by the active encoder 1 stored in the first transmission buffer 24 toward the transmission path 3 (step S705). Then, the standby encoder 2 transmits a transmission confirmation packet of the transmitted video stream to the active encoder 1 (step S706).

  Until a failure occurs, steps S701 to S706 are repeated.

  Here, when a failure occurs in the standby encoder 2 (step S707), the standby encoder 2 stops transmitting the transmission confirmation packet (step S708).

  Then, the active encoder 1 detects the occurrence of a failure in the standby encoder 2 using a non-reception of the transmission confirmation packet from the standby encoder 2 as a trigger (step S709).

  Then, the working encoder 1 identifies the video stream next to the video stream that has received the transmission confirmation packet from the video stream stored in the first transmission buffer 14 in step S703 (step S710).

  Then, the standby encoder 2 creates a video stream after the identified video stream in the transmission path 3. (Step S711).

  As described above, regardless of which of the active encoder 1 and the standby encoder 2 fails, the video stream including the interruption position is stored in the encoder in which no failure has occurred in the previous stage. Thereby, a continuous video stream can be transmitted.

  As described above, in the transmission system according to the present embodiment, the active encoder and the standby encoder are arranged in series. When no failure occurs in each encoder, the video stream encoded by the working encoder is accumulated in the first transmission buffer of the standby encoder, and then transmitted from the standby system to the transmission path. When a failure occurs in the active encoder, the video stream encoded by the standby encoder and the video stream received from the active encoder before the failure are connected and transmitted. When a failure occurs in the standby encoder, a video stream is transmitted from the active encoder.

  That is, the transmission system according to the present embodiment can perform switching when a failure occurs by the own device. In other words, there is no need for switching control by NMS or the like. This eliminates the need for wasted time such as notification of failure occurrence to an external device such as an NMS and reception of a control command. As a result, even when switching to the standby system occurs, the video stream can be continuously transmitted without causing missing data such as dropped frames. Therefore, it is possible to reduce the occurrence of interruption of the video service.

  Further, as in this embodiment, by arranging the working encoder and the standby encoder in series, the circuit scale in the same apparatus can be reduced, and the cost can be reduced.

  Here, in this embodiment, since the roles of the active encoder and the standby encoder are separated, some of the units of the standby encoder do not have the active encoder. However, in order to use any of the encoders for both the active system and the standby system, it is preferable that the encoder serving as the active encoder is provided with a reception buffer and an interruption position specifying unit. As described above, even if the reception buffer and the interruption position specifying unit are provided, the working encoder can perform the operation described in the present embodiment.

  FIG. 10 is a block diagram of an encoding system according to the third embodiment. The transmission system according to the present embodiment is different from the first embodiment in that when switching due to the occurrence of a failure is performed, the failure is corrected and then restored to the state before the occurrence of the failure. Hereinafter, restoring to the state before the occurrence of the failure may be referred to as “switchback”. Therefore, in the following description, the configuration and operation for performing the failback will be mainly described. 10 having the same reference numerals as those in FIG. 2 have the same functions unless otherwise specified.

  The working encoder 1 according to the present embodiment includes a reception buffer 19 and a transmission confirmation notifying unit 171 in addition to the working encoder of the first embodiment. First, each part of the working encoder 1 will be described.

  When the failure of the active encoder 1 is corrected and the failure is corrected, the reception unit 13 receives the input of the video stream encoded by the encoding unit 262 from the transmission unit 22 of the standby encoder 2. Then, the reception unit 13 outputs the video stream to the reception buffer 19.

  In addition, when the failure of the standby encoder 2 is corrected after the failure of the standby encoder 2 is received, the receiving unit 13 receives an input of the video stream from the transmission unit 22 of the standby encoder 2. Then, the reception unit 13 outputs the identification information of the received video stream to the control unit 17.

  The reception buffer 19 receives an input of the video stream from the reception unit 13 and accumulates the video stream. Further, the reception buffer 19 converts the transmission destination address of the accumulated video stream into an address for the end user, and outputs it to the first transmission buffer 14.

  When the failure of the active encoder 1 is corrected and the failure is corrected, the first transmission buffer 14 receives an input of the video stream encoded by the standby encoder 2 from the reception buffer 19 and stores the video stream. I will do it. Then, the first transmission buffer 14 receives and accumulates the video stream after the switching position specified by the control unit 17 from the second transmission buffer 11 as will be described later. At this time, the first transmission buffer 14 changes the transmission destination address for the end user and accumulates the video stream.

  The encoding unit 162 starts encoding the video stream input from the broadcast station 4 when the failure is corrected after the failure of the active encoder 1 occurs. Then, the encoding unit 162 outputs the encoded video stream to the transmission buffer 11. The encoding unit 162 starts encoding the video stream input from the broadcasting station 4 when the failure is corrected after the failure of the active encoder 1 occurs.

  When the failure of the standby encoder 2 occurs and the failure is corrected, the second transmission buffer 11 receives an input of the video stream from the encoding unit 162. Then, the second transmission buffer 11 accumulates the video stream. Similarly, when the failure of the active encoder 1 is corrected after the failure occurs, the second transmission buffer 11 receives the input of the video stream from the encoding unit 162 and accumulates the video stream. Then, the second transmission buffer 11 outputs the video stream after the switching position specified by the control unit 17 to the second transmission buffer 11. Here, the video stream before the switching position stored in the second transmission buffer 11 is discarded.

  When the failure of the standby encoder 2 is corrected after the failure of the standby encoder 2, the transmission unit 12 receives from the control unit 17 an instruction to stop transmission of the video stream toward the end user. Then, the transmission unit 12 stops transmission of the video stream toward the end user. Further, the transmission unit 12 starts transmission of the video stream toward the reception unit 23 of the standby encoder 2. Here, the standby encoder 2 and the active encoder 1 are given a predetermined delay in transmission of the video stream. Therefore, the video stream transmitted from the transmission unit 12 to the reception unit 23 is a video stream that is a predetermined time ahead of the video stream transmitted from the standby encoder 2 that has been corrected for the failure and serves as a failback trigger. . In this embodiment, the video stream is 170 ms ahead.

  Further, when the failure is corrected after the failure of the active encoder 1, the transmission unit 12 transmits the video stream stored in the first transmission buffer 11 to the reception unit 23 of the standby encoder 2. Here, since the video stream after the switching position is stored in the first transmission buffer 11, the transmission unit 12 transmits the video stream after the switching position to the reception unit 23.

  When the failure of the working encoder 1 is corrected, the control unit 17 corrects the video stream stored in the first transmission buffer 14 and the second transmission buffer 11 and the first transmission of the standby encoder 2. The delay time of the buffer 21 is compared, and the switching position of the video stream is specified. Then, the control unit 17 controls the video stream after the switching position to be transferred from the second transmission buffer 11 to the first transmission buffer 14 and stored in the second transmission buffer 11. Further, the control unit 17 controls to delete the video stream stored in the first transmission buffer 14 before the switching position.

  In addition, when the failure of the standby encoder 2 is corrected, the control unit 17 receives a notification from the reception unit 13 that the video stream from the standby encoder 2 has been received. And the control part 17 controls the transmission part 12 not to transmit the video stream after the video stream applicable to the video stream which the receiving part 13 received to an end user. Further, the control unit 17 controls the transmission unit 12 to output the video stream accumulated in the second transmission buffer 11 to the reception unit 23 of the standby encoder 2.

  Next, each part of the standby encoder 2 will be described.

  The receiving unit 23 receives an input of the video stream after the switching position from the transmitting unit 12 of the working encoder 1 when the working encoder 1 is corrected after the failure occurs. Then, the reception unit 23 outputs the video stream to the reception buffer 29.

  The receiving unit 23 receives an input of a video stream from the transmitting unit 12 of the active encoder 1 when the standby encoder 2 is corrected after the failure. Then, the reception unit 23 outputs the video stream to the reception buffer 29.

  The reception buffer 29 receives an input of the video stream from the reception unit 23 and accumulates the video stream. Further, the reception buffer 29 converts the transmission destination address of the accumulated video stream into an address for the end user, and outputs it to the first transmission buffer 24.

  When the failure of the working encoder 1 is corrected, the first transmission buffer 24 receives the input of the video stream after the switching position from the reception buffer 29 and accumulates the video stream.

  In addition, when the first transmission buffer 24 is corrected after the failure of the standby encoder 2, the first transmission buffer 24 receives the input of the video stream from the reception buffer 29 and accumulates the video stream. Here, the video stream stored in the first transmission buffer 24 is a video stream after a video stream that is a predetermined time ahead of the video stream transmitted from the standby encoder 2 whose fault is corrected and becomes a trigger for switching back. . For example, assuming that the delay time corresponds to a time for transmitting a video stream for five frames, the first transmission buffer 24 stores video streams after the video stream five times after the video stream for which the standby encoder 2 has resumed transmission. Will be accumulated.

  When the failure of the working encoder 1 is corrected, the encoding unit 262 receives from the control unit 27 an instruction to stop encoding the video stream after the switching position specified by the control unit 27. Then, the encoding unit 262 stops encoding the video stream after the switching position.

  The encoding unit 262 starts encoding the video stream from the broadcast station 4 when the standby encoder 2 is corrected after the failure occurs. Then, the encoding unit 262 outputs the encoded video stream to the second transmission buffer 21. Then, when the encoding unit 262 receives a video frame from the working encoder 1, the encoding unit 262 ends the encoding of the video stream. However, it is assumed that the encoding unit 262 performs encoding up to a video stream ahead of a predetermined time with respect to the video stream transmitted from the standby encoder 2 serving as a failback trigger after correcting the failure.

  When the second transmission buffer 21 is corrected after the failure of the active encoder 1, the second transmission buffer 21 receives the video stream input from the encoding unit 262 until the encoding unit 262 stops encoding, and the video Accumulate the stream.

  When the second transmission buffer 21 is corrected after the failure of the standby encoder 2, the second transmission buffer 21 receives the video stream input from the encoding unit 262 until the encoding unit 262 stops encoding, The video stream is accumulated.

  The transmission unit 22 reads the video stream encoded by the encoding unit 262 from the second transmission buffer 21 and sends it out to the transmission path 3 until the active encoder 1 is corrected after the failure occurs. When the correction is made, the transmission unit 22 reads the video stream after the switching position specified by the control unit 27 from the first transmission buffer 24 and sends it to the transmission path 3.

  In addition, when correction is made after the failure of the standby encoder 2, the transmission unit 22 specifies the control unit 27 in the video stream encoded by the encoding unit 262 stored in the second transmission buffer 21. The video stream after the switched position is sent to the transmission path 3. Further, the transmission unit 22 transmits the same video stream as the video stream transmitted to the transmission path 3 to the reception unit 13 of the working encoder 1. Then, the transmission unit 22 reads the video stream encoded by the own apparatus stored in the second transmission buffer 21 from the video stream first transmitted to the reception unit 13 to the video stream ahead of a predetermined time, and transmits the transmission path. Output to 3. Then, the transmission unit 22 reads from the second transmission buffer 24 the video stream after the video stream that is a predetermined time ahead from the video stream first transmitted to the reception unit 13, and sends it to the transmission path 3.

  When the failure of the working encoder 1 is corrected, the control unit 27 compares the video streams stored in the first transmission buffer 24 and the second transmission buffer 21 and identifies the switching position. . Specifically, the first transmission buffer 24 stores a video stream before the switching position specified by the control unit 17. The second transmission buffer 21 stores the video stream encoded by the encoding unit 262, and this video stream includes the video stream at the switching position specified by the control unit 17. Therefore, the control unit 27 specifies the switching position specified by the control unit 17 in the video stream stored in the second transmission buffer 21. Then, the control unit 27 controls the transmission unit 22 so as to transmit the video stream accumulated in the second transmission buffer 21 until the specified switching position. Then, the control unit 27 controls the transmission unit 22 so as to send out the video stream stored in the first transmission buffer 24 after the identified switching position.

  Further, when the failure of the standby encoder 2 is corrected, the control unit 27 uses the delay times in the first transmission buffer 24, the second transmission buffer 21, and the second transmission buffer 21, Specify the switching position. For example, the control unit 27 identifies one of the video streams stored in the first transmission buffer 24 and after the delay time as a switching position. Then, the control unit 27 reads out the video stream corresponding to the delay time from the video stream at the specified switching position from the second transmission buffer 24, and sends the video stream to the transmission unit 3 and the reception unit 13 of the working encoder 1. To control. Further, the control unit 27 reads the video stream after the delay time from the video stream at the specified switching position from the first transmission buffer 24 and sends the video stream to the transmission unit 3 and the reception unit 13 of the working encoder 1. To control.

  Next, referring to FIG. 11, the overall processing flow of failback when an active system failure occurs will be described. Here, FIG. 11 is a diagram for explaining switch-back processing when an active system failure occurs.

  In FIG. 11, the flow of data before switchback is indicated by a dotted arrow, and the data flow after switchback is indicated by a solid arrow.

  Before a failure occurs in the active encoder 1, the video stream transmitted from the broadcast station 4 is input to the standby encoder 2 via the Matrix SW 5 (step S801). Then, standby encoder 2 transmits the video stream to the end user via the IP network via switch 6 and router 7 (step S802). Further, standby encoder 2 transmits the video stream to active encoder 1 (step S803).

  When the failure of the active encoder 1 is corrected, the active encoder 1 can receive the video stream transmitted from the standby encoder 2 in step S803. Thereby, failback is started. The processing in this case is as follows. That is, the working encoder 1 receives the video stream transmitted from the broadcast station 4 (step S804). Then, the working encoder 1 compares the video streams stored in the first transmission buffer 14 and the second transmission buffer 11 with the delay time of the first transmission buffer 21 of the standby encoder 2, and sets the switching position. Identify. Then, the working encoder 1 transmits the video stream after the switching position to the standby encoder 2 (step S805). The standby encoder 2 transmits the video stream after the switching position received from the active encoder 1 via the switch 6 and the router 7 to the end user via the IP network (step S806). Further, the standby encoder 2 transmits a transmission confirmation packet of the video stream transmitted to the end user to the active encoder 1 (step S807).

  Next, with reference to FIG. 12, the overall processing flow of switchback when a standby system failure occurs will be described. Here, FIG. 12 is a diagram for explaining switch-back processing when a standby system failure occurs.

  In FIG. 12, the dotted line arrows indicate the data flow before the switchback, and the solid line arrows indicate the data flow after the switchback.

  Before a failure occurs in the working encoder 1, the video stream transmitted from the broadcasting station 4 is input to the working encoder 1 via the Matrix SW 5 (step S901). Then, the active encoder 1 transmits the video stream to the end user via the IP network via the switch 6 and the router 7 (step S902).

  A case where the failure of the standby encoder 2 is corrected will be described. The working encoder 1 receives the video stream transmitted from the broadcast station 4 (step S903). Then, the working encoder 1 transmits the video stream to the standby encoder (step S904). However, at this time, transmission of the video stream is performed by the working encoder 1 in step S902. Then, the standby encoder 2 transmits a transmission confirmation packet to the active encoder 1 (step S905). The standby encoder 2 identifies the switching position using the video streams stored in the first transmission buffer 24 and the second transmission buffer 21 and the delay time of the first transmission buffer 21. Then, the standby encoder 2 transmits the video stream after the switching position via the switch 6 and the router 7 to the end user via the IP network (step S906). Then, transmission of the video stream by the active encoder 1 in step S902 is not performed on the video stream after the switching position.

  Next, with reference to FIG. 13, the flow of the failback process when a failure occurs in the working encoder 1 will be described. FIG. 13 is a sequence diagram of switchback processing when a failure occurs in the working encoder. Each vertical axis | shaft of FIG. 13 shows progress of time on the lower side toward the paper surface.

  The standby encoder 2 sends the video stream encoded by the standby encoder 2 to the transmission path 3 when the active encoder 1 fails (step S1001).

  When failure recovery is performed in the active encoder 1 (step S1002), the active encoder 1 receives the video stream from the standby encoder 2 (step S1003). Then, the active encoder 1 accumulates the video stream received from the standby encoder 2 in the first transmission buffer 11 (step S1004). Then, the working encoder 1 starts encoding the video stream, and accumulates the encoded video stream in the second transmission buffer 14 (step S1005). Then, the working encoder 1 sets the switching position using the video streams stored in the first transmission buffer 11 and the second transmission buffer 14 and the delay time of the first transmission buffer 24 of the standby encoder 2. Specify (step S1006). Then, the working encoder 1 transmits the video stream after the switching position to the standby encoder 2 (step S1007).

  The standby encoder 2 stores the video stream received from the active encoder 1 in the first transmission buffer 24 and compares it with the video stream stored in the second transmission buffer 21 to identify the switching position ( Step S1008). The standby encoder 2 stops encoding (step S1009), and sends the video stream encoded by the active encoder 1 as the video stream after the switching position to the transmission path 3 (step S1010). Then, the standby encoder 2 transmits a transmission confirmation packet of the transmitted video stream to the active encoder 1 (step S1011).

  Next, with reference to FIG. 14, the flow of the failback process when a failure occurs in the standby encoder 2 will be described. FIG. 14 is a sequence diagram of switch-back processing when a failure occurs in the standby encoder. Each vertical axis | shaft of FIG. 14 shows progress of time on the lower side toward the paper surface.

  The active encoder 1 sends the video stream encoded by the active encoder 1 to the transmission path 3 when the standby encoder 2 fails (step S1101).

  When failure recovery is performed in the standby encoder 2 (step S1102), the standby encoder 2 starts encoding the video stream and accumulates the encoded video stream in the second transmission buffer 21 (step S1103). .

  The active encoder 1 transmits the video stream encoded by the own apparatus to the standby encoder 2 (step S1104).

  The standby encoder 2 accumulates the video stream received from the active encoder 1 in the first transmission buffer 24 (step S1105). Then, standby encoder 2 transmits a transmission confirmation packet to active encoder 1 (step S1106). Further, the standby encoder 2 identifies the switching position using the video streams stored in the first transmission buffer 24 and the second transmission buffer 21 and the delay time of the first transmission buffer 24 (step S1107). Then, the standby encoder 2 sends the video stream encoded by itself to the specified switching position to the transmission path 3 (step S1108).

  The active encoder 1 transmits the video stream to the standby encoder 2 (step S1109).

  The standby encoder 2 stops encoding in its own apparatus (step S1110), and sends the video stream encoded by the active encoder 1 to the transmission path 3 as a video stream after the switching position (step S1111).

  As described above, in the transmission system according to the present embodiment, when the failure of the failed encoder is recovered in the state of being switched due to the occurrence of the failure, the failure before the failure occurs without using an external device such as an NMS. Restore to the state. As a result, even when the state before the occurrence of the failure is restored, it is possible to provide a continuous video service without interrupting the video stream due to dropped frames.

  Further, in this embodiment, a configuration has been described in which when a failure occurs, the configuration is restored to the state before the failure occurred. For example, when a failure occurs in the active encoder, the active encoder and the standby encoder are restored after the failure is recovered. The roles may be reversed. In that case, an interruption position specifying unit is also provided in the working encoder.

  The transmission system according to the present embodiment is different from the first to third embodiments in that switching can be performed even when a failure other than the failure that the video stream cannot be transmitted occurs. In the following, switching in a failure other than the failure that the video stream cannot be transmitted will be mainly described. In the following description, a transmission system in which a switching function in a failure other than the failure that the video stream cannot be transmitted is added to the second embodiment will be described as an example. The transmission system according to the present embodiment is represented by the block diagram shown in FIG.

  The control unit 17 stores a failure detection condition for detecting the occurrence of a failure. The failure detection condition is, for example, an upper limit value of temperature. Then, the control unit 17 monitors the states of the second transmission buffer 11, the transmission unit 12, the reception unit 13, the first transmission buffer 14, the network interface 18, the signal input unit 161, the encoding unit 162, and the like, for example. ing. And the control part 21 detects generation | occurrence | production of a failure, when the state which satisfy | fills failure detection conditions generate | occur | produces in the monitoring object. For example, the control unit 21 detects the occurrence of a failure when the temperature in the encoding unit 162 is equal to or higher than a predetermined temperature. Here, the failure detected by the control unit 17 is a minor error compared to an error in which the video stream cannot be transmitted.

  When detecting the occurrence of a failure, the control unit 17 transmits a notification of the occurrence of the failure to the control unit 27. For the notification of the occurrence of the failure, it is preferable to use a control packet as shown in FIG. The address of the standby encoder is used as the transmission destination address of the address field 301 in the control packet used for notifying the occurrence of the failure. Further, the transmission confirmation / control field 302 includes failure notification information. When switching or failback is performed, the transmission confirmation / control field 302 includes switching / switchback control information. Further, the data area 303 includes an operation state and the like. Then, the control unit 17 controls each unit so as to perform the same operation as when the video encoder is not transmitted from the active encoder 1. Specifically, control is performed so as to ignore the reception confirmation packet reception notification from the receiving unit 13. In addition, the control unit 17 performs control such that the transmission unit 12 does not transmit the video stream.

  Further, when a failure other than the failure that the standby encoder 2 cannot transmit the video stream occurs, the control unit 17 receives a notification of the failure from the control unit 27. In this case, the control unit 17 controls each unit so that each unit performs the same operation as when the video stream cannot be transmitted in the standby encoder 2. Specifically, the control unit 17 reads the video stream from the frame next to the frame corresponding to the last received transmission confirmation packet from the first transmission buffer 14 and transmits the read video stream to the end user. The transmitter 12 is controlled.

  The control unit 27 stores a failure detection condition for detecting the occurrence of a failure. Then, the control unit 27 includes, for example, the second transmission buffer 21, the transmission unit 22, the reception unit 23, the first transmission buffer 24, the interruption position specifying unit 25, the network interface 28, the signal input unit 261, and the encoding unit 262. The status is monitored. Then, the control unit 27 detects the occurrence of a failure when a condition that satisfies the condition occurs in the monitoring target.

  When detecting the occurrence of a failure, the control unit 27 transmits a notification of the occurrence of the failure to the control unit 17. Then, the control unit 27 controls each unit so as to perform the same operation as when the video stream cannot be transmitted from the standby encoder 2. Specifically, the control unit 27 performs control such that data is not transmitted to the transmission unit 22.

  In addition, when a failure other than the failure in which the video encoder cannot be transmitted in the active encoder 1 occurs, the control unit 27 receives a notification of the occurrence of the failure from the control unit 17. In this case, the control unit 27 controls each unit so that each unit performs the same operation as when the active stream encoder 1 cannot transmit the video stream. Specifically, the control unit 27 controls each unit so that the interruption position is specified, the video streams are connected, the connected video streams are transmitted, and the like.

  As described above, the transmission system according to the present embodiment performs switching even when a failure other than a failure in which a video stream cannot be transmitted occurs. In this regard, there may be a case where normal processing cannot be performed even if the video stream can be transmitted. If a video stream that cannot be processed normally is transmitted, there is a possibility that a normal video service cannot be provided. Therefore, the transmission system according to the present embodiment can reduce service interruption and provide a more secure redundant configuration.

  Furthermore, it is also possible to add the NMS 8 as shown in FIG. 15 to the configuration of each embodiment described above. The NMS 8 manages the encoder group including the active encoder 1 and the standby encoder 2, the Matrix SW 5, the switch 6, and the router 7 via a management line 81 represented by a dotted line. As described above, by adding the NMS 8, it is possible to perform switching via the NMS 8. Thereby, it becomes possible to raise redundancy more.

  The following supplementary notes are further disclosed with respect to the embodiments including the above examples.

(Supplementary Note 1) A first encoding unit that encodes a video signal from an external device, stores the encoded video signal in a buffer, and transmits the video signal stored in the buffer;
A video signal that receives the video signal transmitted by the first encoding unit, encodes the video signal from the external device, and gives a delay of a predetermined time to the video signal transmitted by the first encoding unit; A second encoding unit that selectively sends any of the video signals encoded by the device to the transmission line;
The first encoding unit, when a failure occurs in the second encoding unit, sends a video signal encoded by itself to the transmission path,
The encoding apparatus, wherein the second encoding unit sends out a video signal encoded by the second encoding unit to the transmission line when a failure occurs in the first encoding unit.

(Supplementary Note 2) After a failure occurs in either the first encoding unit or the second encoding unit, when the failure is recovered, the first encoding unit transfers to the second encoding unit. The encoding apparatus according to appendix 1, wherein the video signal is transmitted, and the second encoding unit transmits the signal received from the first encoding unit to a transmission path.

(Supplementary Note 3) The first encoding unit includes:
A first processing unit that encodes a video signal from the external device;
A transmission buffer for storing the video signal encoded by the first encoding unit;
A first transmission unit for transmitting the video signal accumulated in the transmission buffer,
The second encoding unit includes:
A receiving unit for receiving the video signal transmitted by the first encoding unit;
A first transmission buffer for storing a video signal received by the receiver;
A second processing unit for encoding a video signal received from the external device;
The second transmission buffer for storing the video signal encoded by the second encoding unit;
The first transmission buffer in the video signal stored in the second transmission buffer by comparing the video signal stored in the second transmission buffer with the video signal stored in the first transmission buffer. An interrupt position specifying unit for specifying a position that matches the interrupted position of the video signal stored in
When the receiving unit does not receive the video signal transmitted by the first encoding unit, it is determined that a failure has occurred in the first encoding unit, and based on the position specified by the interruption position specifying unit, A control unit for connecting the video signal stored in the first transmission buffer and the video signal stored in the second transmission buffer;
When the receiving unit receives the video signal transmitted by the first encoding unit, the video signal stored in the first transmission buffer is delayed by a predetermined time and sent to the transmission line, The supplementary note 1 or the supplementary note 2, further comprising: a second transmission unit that sends out the video signal connected by the control unit when the reception unit does not receive the video signal transmitted by the encoding unit. Encoding device.

(Additional remark 4) The said 2nd encoding part is provided with the transmission confirmation notification part which notifies a transmission confirmation to a said 1st transmission part, when the said 2nd transmission part sends out the video signal which the said reception part received. ,
The first encoding unit includes an information reception unit that receives a notification of transmission confirmation from the transmission confirmation notification unit,
The first transmission unit determines that a failure has occurred in the second encoding unit when the information reception unit does not receive the notification of transmission confirmation, and the video signal stored in the transmission buffer is The encoding apparatus according to appendix 3, wherein the encoding apparatus is sent to a transmission line.

(Supplementary Note 5) The first encoding unit includes:
When the information receiving unit receives an input of the video signal from the second transmitting unit after the receiving unit no longer receives the video signal transmitted by the first encoding unit, the information is stored in the transmission buffer. A first control unit for identifying a switching position in the video signal being
The first transmission unit transmits a video signal after the specified switching position to the reception unit,
The second transmission unit reads and transmits a video signal before the specified switching position from the second transmission buffer, and reads a video signal after the specified switching position from the first transmission buffer. The encoding apparatus according to appendix 3 or appendix 4, wherein the encoding device is transmitted.

(Appendix 6) The first transmission unit transmits the video signal to the reception unit when the video signal can be transmitted after the information reception unit no longer receives the notification of the transmission confirmation.
When the receiving unit receives a video signal from the first transmitting unit after the information receiving unit no longer receives the notification of transmission confirmation, the control unit stores the video signal stored in the second transmission buffer. Identify the switching position at
The second transmission unit reads and transmits a video signal before the specified switching position from the second transmission buffer, and reads a video signal after the specified switching position from the first transmission buffer. The encoding apparatus according to any one of Supplementary Note 3 to Supplementary Note 5, wherein:

(Supplementary Note 7) The first encoding unit further includes a first abnormality detection unit that detects a predetermined abnormality,
The control unit determines that a failure has occurred in the first encoding unit when the abnormality detection unit detects a predetermined abnormality, and the video signal accumulated in the first transmission buffer; 2 Connect the data stored in the transmission buffer,
The encoding device according to any one of Supplementary Note 3 to Supplementary Note 6, wherein the transmission unit transmits a video signal connected by the control unit.

(Supplementary Note 8) The second encoding unit further includes a second abnormality detection unit that detects abnormality,
The first transmission unit determines that a failure has occurred in the second encoding unit when the second abnormality detection unit detects an abnormality, and transmits the video signal accumulated in the transmission buffer to the transmission The encoding apparatus according to any one of appendix 3 to appendix 7, wherein the encoding device is sent to a road.

(Supplementary note 9) An encoding system having a first encoding device and a second encoding device,
The first encoding device encodes a video signal from an external device, accumulates the encoded video signal in a buffer, transmits the video signal stored in the buffer, and transmits the second encoding When a failure occurs in the part, it sends a video signal encoded by itself to the transmission path,
The second encoding device receives the video signal transmitted from the first encoding unit, performs a process on the video signal from the external device, and performs predetermined processing on the video signal transmitted from the first encoding unit. Either a video signal given a time delay or a video signal encoded by itself is selectively sent to the transmission line, and when a failure occurs in the first encoding unit, the video signal encoded by itself Is sent out to the transmission line.

(Supplementary Note 10) The first encoding device encodes the video signal from the external device;
Storing the encoded video signal in a buffer of the first encoding device;
Transmitting the video signal stored in the buffer of the first encoding device to a second encoding device;
The second encoding device receiving the video signal transmitted from the first encoding device;
A step in which the second encoding device gives a delay of a predetermined time to the video signal received from the first encoding device and sends it to the transmission line;
Detecting the occurrence of a failure in the first encoding device or the second encoding device; and detecting the failure, to the transmission path of the video signal transmitted by the first encoding device by the second encoding device A step to stop sending
When the second encoding device sends a video signal encoded by the second encoding device to the transmission line when a failure occurs in the first encoding device;
The second encoding device encoding the video signal from the external device when a failure occurs in the second encoding unit;
And a step of transmitting the video signal encoded by the first encoding device to the transmission path by the first encoding device.

1 Active encoder (active encoder)
2 Standby encoder (Standby encoder)
3 Transmission path 4 Broadcasting station 5 MatrixSW
6 switch 7 router 11, 21 second transmission buffer 12, 22 transmission unit 13, 23 reception unit 14, 24 first transmission buffer 16, 26 data processing unit 17, 27 control unit 18, 28 network interface 19, 29 reception Buffer 25 Interruption position specifying unit 161, 261 Signal input unit 162, 262 Encoding unit 171, 271 Transmission confirmation notifying unit

Claims (7)

A first encoding unit that encodes a video signal from an external device, stores the encoded video signal in a buffer, and transmits the video signal stored in the buffer;
A video signal that receives the video signal transmitted by the first encoding unit, encodes the video signal from the external device, and gives a delay of a predetermined time to the video signal transmitted by the first encoding unit; A second encoding unit that selectively sends any of the video signals encoded by the device to the transmission line;
The first encoding unit, when a failure occurs in the second encoding unit, sends a video signal encoded by itself to the transmission path,
The encoding apparatus, wherein the second encoding unit sends out a video signal encoded by the second encoding unit to the transmission line when a failure occurs in the first encoding unit. The first encoding unit includes:
A first processing unit that encodes a video signal from the external device;
A transmission buffer for storing the video signal encoded by the first encoding unit;
A first transmission unit for transmitting the video signal accumulated in the transmission buffer,
The second encoding unit includes:
A receiving unit for receiving the video signal transmitted by the first encoding unit;
A first transmission buffer for storing a video signal received by the receiver;
A second processing unit for encoding a video signal received from the external device;
The second transmission buffer for storing the video signal encoded by the second encoding unit;
The first transmission buffer in the video signal stored in the second transmission buffer by comparing the video signal stored in the second transmission buffer with the video signal stored in the first transmission buffer. An interrupt position specifying unit for specifying a position that matches the interrupted position of the video signal stored in
When the receiving unit does not receive the video signal transmitted by the first encoding unit, it is determined that a failure has occurred in the first encoding unit, and based on the position specified by the interruption position specifying unit, A control unit for connecting the video signal stored in the first transmission buffer and the video signal stored in the second transmission buffer;
When the receiving unit receives the video signal transmitted by the first encoding unit, the video signal stored in the first transmission buffer is delayed by a predetermined time and sent to the transmission line, 2. The code according to claim 1, further comprising: a second transmission unit configured to transmit the video signal connected by the control unit when the reception unit does not receive the video signal transmitted by the encoding unit. Device. The second encoding unit includes a transmission confirmation notification unit that notifies the first transmission unit of transmission confirmation when the second transmission unit transmits the video signal received by the reception unit,
The first encoding unit includes an information reception unit that receives a notification of transmission confirmation from the transmission confirmation notification unit,
The first transmission unit determines that a failure has occurred in the second encoding unit when the information reception unit does not receive the notification of transmission confirmation, and the video signal stored in the transmission buffer is The encoding apparatus according to claim 2, wherein the encoding apparatus sends the data to a transmission line. The first encoding unit includes:
When the information receiving unit receives an input of the video signal from the second transmitting unit after the receiving unit no longer receives the video signal transmitted by the first encoding unit, the information is stored in the transmission buffer. A first control unit for identifying a switching position in the video signal being
The first transmission unit transmits a video signal after the specified switching position to the reception unit,
The second transmission unit reads and transmits a video signal before the specified switching position from the second transmission buffer, and reads a video signal after the specified switching position from the first transmission buffer. The encoding apparatus according to claim 2, wherein the encoding apparatus is transmitted. The first transmission unit transmits the video signal to the reception unit when the video signal can be transmitted after the information reception unit no longer receives the notification of the transmission confirmation.
When the receiving unit receives a video signal from the first transmitting unit after the information receiving unit no longer receives the notification of transmission confirmation, the control unit stores the video signal stored in the second transmission buffer. Identify the switching position at
The second transmission unit reads and transmits a video signal before the specified switching position from the second transmission buffer, and reads a video signal after the specified switching position from the first transmission buffer. The encoding device according to any one of claims 2 to 4, wherein the encoding device is transmitted. An encoding system having a first encoding device and a second encoding device,
The first encoding device encodes a video signal from an external device, accumulates the encoded video signal in a buffer, transmits the video signal stored in the buffer, and transmits the second encoding When a failure occurs in the part, it sends a video signal encoded by itself to the transmission path,
The second encoding device receives the video signal transmitted from the first encoding unit, performs a process on the video signal from the external device, and performs predetermined processing on the video signal transmitted from the first encoding unit. Either a video signal given a time delay or a video signal encoded by itself is selectively sent to the transmission line, and when a failure occurs in the first encoding unit, the video signal encoded by itself Is sent out to the transmission line. A first encoding device encoding a video signal from an external device;
Storing the encoded video signal in a buffer of the first encoding device;
Transmitting the video signal stored in the buffer of the first encoding device to a second encoding device;
The second encoding device receiving the video signal transmitted from the first encoding device;
A step in which the second encoding device gives a delay of a predetermined time to the video signal received from the first encoding device and sends it to the transmission line;
Detecting the occurrence of a failure in the first encoding device or the second encoding device; and detecting the failure, to the transmission path of the video signal transmitted by the first encoding device by the second encoding device A step to stop sending
When the second encoding device sends a video signal encoded by the second encoding device to the transmission line when a failure occurs in the first encoding device;
The second encoding device encoding the video signal from the external device when a failure occurs in the second encoding unit;
And a step of transmitting the video signal encoded by the first encoding device to the transmission path by the first encoding device.

Images