JP2014192715A - Video storage and distribution device, system, method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow important video such as at the time of occurrence of an earthquake to be protected against overwriting.SOLUTION: An encoder control unit 34 circularly overwrites and stores video data that are sequentially input from a video photographing unit 12 and encoded by encoding units 24A, 24B in a storage unit 30. However, the encoder control unit 34 excludes video data input during a time from a first time point when the amount of change in video exceeds a first threshold value, the interruption of communication with an operation PC of a video utilization system 18 is detected, and an emergency earthquake prompt report signal is obtained from an emergency earthquake prompt report system 20 to a second time point when a state in which the amount of change in the video is at or below a second threshold value continued for a prescribed time period or more from an object to be overwritten and stores the video data in the storage unit 30.

Description

  The present invention relates to a video accumulation / delivery device, a video accumulation / delivery system, a video accumulation / delivery method, and a video accumulation / delivery program.

  The following techniques have been proposed as techniques for storing an emergency video such as an earthquake. When the first technique detects at least one of vibration, wind speed, and rainfall exceeding a reference value, it records an image taken by a camera capable of taking pictures of the outside of the house on a video recording means, and also displays a display screen. Real time display.

  The second technique is that when a shake sensor detects a shake of an earthquake, it starts from the execution of a shot in which a subject that clearly understands the state of the shake at the time of the earthquake occurs, the start of VTR recording, and the long recording speed mode. Command to switch to standard mode.

JP 2006-331150 A Japanese Patent Laid-Open No. 10-104738

  When saving an emergency video such as an earthquake, the storage capacity of the storage unit that stores the video is limited, so it is realistic to store the video in the storage unit cyclically overwriting. is there. On the other hand, neither the first technique nor the second technique describes at what timing the storage of the video started by detecting vibration or the like is terminated. For this reason, when each of the above technologies starts to detect vibration or the like and store the video in the storage unit, the video stored in the storage unit will eventually become full, and the video will be stored in the storage unit. As a result, a part of the emergency video may be overwritten and erased.

  An object of the present invention, as one aspect, is to protect important images such as when an earthquake occurs from being overwritten.

  In one aspect, the processing unit cyclically overwrites and stores sequentially input video data in the storage unit. The video change amount acquisition unit acquires the change amount of the video represented by the video data. The control unit receives a second state in which a state in which the video change amount is equal to or less than a second threshold continues for a predetermined time from a first time point when the video change amount acquired by the video change amount acquisition unit exceeds a first threshold value. Video data input during the period up to the time point is excluded from overwriting and stored in the storage unit.

  As one aspect, there is an effect that important images such as when an earthquake occurs can be protected from being overwritten.

It is a block diagram which shows an example of schematic structure of the image | video accumulation | storage delivery system demonstrated by embodiment. It is a schematic block diagram which shows an example of the hardware constitutions of an encoder. It is a flowchart which shows an example of a preset process. It is a flowchart which shows an example of a video protection process. It is a schematic diagram showing an example of storage and protection of video data in a storage part. It is a diagram which shows an example of the variation | change_quantity of the image | video which video data represents. It is the schematic which shows an example of the state by which video data was memorize | stored in the memory | storage part.

  Hereinafter, an example of an embodiment of the disclosed technology will be described in detail with reference to the drawings. FIG. 1 shows a video storage / delivery system 10 according to the present embodiment. The video storage / delivery system 10 includes a video shooting unit 12, an encoder 14 connected to the video shooting unit 12, a video use system 18 connected to the encoder 14 via a network 16, and an emergency earthquake warning system 20. .

  The image capturing unit 12 is arranged to capture images of a certain subject (for example, a subject that can be seen from the rooftop of a building or a subject that is located in a certain indoor room) like a fixed point camera, and is collected by a microphone. A video signal that represents the video of the subject, including the sound signal that was sounded, is always output. The video photographing unit 12 is an example of a photographing device in the disclosed technology.

  The encoder 14 is an example of a video storage / delivery device according to the disclosed technology. The encoder 14 encodes the video signal input from the video shooting unit 12, stores the encoded video data, and distributes the video data to the video utilization system 18.

  The video use system 18 is an example of an external device in the disclosed technology, and receives video data shot by the video shooting unit 12 and encoded by the encoder 14 via the network 16. The video utilization system 18 is typically a computer system including one or more operation PCs (Personal Computers) installed in a television broadcasting station. Video data is received by the operation PC, and the video received by the operation PC. The video represented by the data is used for television broadcasting. Note that the encoder according to the present embodiment can distribute video data to a plurality of (for example, a maximum of four) operation PCs.

  The emergency earthquake bulletin system 20 is a computer system that transmits an emergency earthquake bulletin signal to a destination registered in advance via the network 16 when it is detected that an earthquake having a maximum seismic intensity greater than a predetermined value has occurred. In the present embodiment, the transmission destination of the emergency earthquake warning signal registered in the earthquake early warning system 20 includes the encoder 14.

  Next, details of the encoder 14 will be described. The encoder 14 includes a video / audio signal input unit 22, two video / audio signal encoding units 24A and 24B, a video / audio multiplexing unit 26, a transmission unit 28, a storage unit 30, a LAN I / F unit 32, and an encoder. A control unit 34 is provided. The video / audio signal input unit 22 acquires a video signal including the audio signal input from the video shooting unit 12.

  The video / audio signal encoding units 24A and 24B encode the video signal acquired by the video / audio signal input unit 22 by a predetermined encoding method. The video / audio signal encoding units 24A and 24B have different encoding bit rates. The video / audio signal encoding unit 24A performs encoding at a first encoding rate (for example, about 3 to 8 Mbps), and the video / audio signal encoding unit 24B performs a second code lower than the first encoding rate. Encoding is performed at an encoding rate (for example, about 384 kbps). In the present embodiment, the video / audio signal encoding unit 24A is referred to as a main encoder and the video / audio signal encoding unit 24B is referred to as a sub-encoder as necessary.

  The video / audio signal encoding units 24A and 24B are examples of the encoding unit in the disclosed technology. More specifically, the video / audio signal encoding unit 24A is an example of the first encoding unit in the disclosed technology. The audio signal encoding unit 24B is an example of a second encoding unit in the disclosed technology.

  The video / audio multiplexing unit 26 multiplexes a plurality of video data streams output from the video / audio signal encoding units 24A and 24B into a single video data stream. The transmission unit 28 transmits the video data stream output from the video / audio multiplexing unit 26 to the video utilization system 18 via the LAN I / F unit 32 and the network 16. The storage unit 30 cyclically overwrites and stores the video data sequentially output from the video / audio multiplexing unit 26. As shown in FIG. 2, the storage unit 30 can be realized by a memory card such as a flash memory (specifically, for example, a compact flash (registered trademark) card).

  The encoder control unit 34 controls the operation of each unit of the encoder 14. The encoder control unit 34 includes a trigger acquisition unit 36, a video change amount acquisition unit 38, a setting value reflection unit 40, a setting value reception unit 42, a control unit 44, a setting value storage unit 46, and a processing unit 48.

  The trigger acquisition unit 36 acquires the earthquake early warning signal transmitted from the earthquake early warning system 20. The trigger acquisition unit 36 acquires the number of video data distributed from the main encoder and the sub encoder to the operation PC of the video usage system 18. In addition, the trigger acquisition unit 36 acquires an earthquake early warning signal from the earthquake early warning system 20, and when the number of distributions of video data from the main encoder and the sub encoder to the operation PC of the video utilization system 18 becomes zero. Notify the controller 44. The trigger acquisition unit 36 is an example of an emergency signal acquisition unit and a detection unit in the disclosed technology.

  The video change amount acquisition unit 38 acquires the video change amount represented by the video data, and notifies the control unit 44 of the acquired video change amount. Note that as the amount of change in video, for example, the magnitude of a motion vector in interframe coding can be applied. The video change amount acquisition unit 38 is an example of a video change amount acquisition unit in the disclosed technology.

  The control unit 44 changes the activation state of the setting value storage unit 46 from off to on when the emergency earthquake warning signal is acquired and the trigger acquisition unit 36 is notified that the number of video data distributions is zero. Switch to. In addition, when the video change amount notified from the video change amount acquisition unit 38 exceeds the protection start threshold value (an example of the first threshold value), the control unit 44 requests the processing unit 48 to start protecting the video data. When the video data protection end condition is satisfied, the control unit 44 switches the activation state of the setting value storage unit 46 from on to off, and requests the processing unit 48 to end the video data to be protected. When the video data protection end condition is satisfied, the state where the video change amount notified from the video change amount acquisition unit 38 is equal to or less than the protection end threshold (an example of the second threshold) is the stop determination time (predetermined time). Example) is a case of continuing. The control unit 44 is an example of a control unit in the disclosed technology.

  When the control unit 44 requests the video data to be protected, the processing unit 48 sets the video data protection start time in the setting value storage unit 46 and requests the setting value reflection unit 40 to reflect the information. When the control unit 44 requests the video data protection end, the processing unit 48 sets the video data protection end time in the setting value storage unit 46 and requests the setting value reflection unit 40 to reflect the information. The processing unit is an example of a processing unit in the disclosed technology.

  The set value reflecting unit 40 reflects the information stored in the set value storing unit 46 and the existing set value of the encoder 14 in the main body of the encoder 14. The setting value receiving unit 42 receives the setting information and causes the setting value storage unit 46 to store the received setting information. The setting value storage unit 46 stores the information transferred from the setting value receiving unit 42 and the information transferred from the control unit 44 and the processing unit 48.

  For example, as shown in FIG. 2, the encoder 14 can be realized by hardware having a configuration in which a computer 50 is built. The computer 50 includes a CPU 52, a memory 54, a storage unit 56, and an I / F unit 58. The CPU 52, the memory 54, the storage unit 56, and the I / F unit 58 are connected to each other via a bus 60. The I / F unit 58 is connected to the video / audio signal input unit 22, the video / audio signal encoding units 24A and 24B, the video / audio multiplexing unit 26, the transmission unit 28, the storage unit 30, and the LAN I / F unit 32, respectively. It is connected. Further, the I / F unit 58 is connected to a connector 78 provided in the casing of the encoder 14. The connector 78 is connected to a setting PC 80 when setting information is input to the encoder 14.

  The storage unit 56 can be realized by an HDD (Hard Disk Drive), a flash memory, or the like. The storage unit 56 stores an encoder control program 62 for causing the computer 50 to function as the encoder control unit 34. The CPU 52 reads the encoder control program 62 from the storage unit 56 and develops it in the memory 54, and sequentially executes the processes included in the encoder control program 62. The encoder control program 62 includes a trigger acquisition process 64, a video change amount acquisition process 66, a setting value reflection process 68, a setting value reception process 70, a control process 72 and a processing process 74.

  The CPU 52 operates as the trigger acquisition unit 36 illustrated in FIG. 1 by executing the trigger acquisition process 64. The CPU 52 operates as the video change amount acquisition unit 38 illustrated in FIG. 1 by executing the video change amount acquisition process 66. The CPU 52 operates as the set value reflecting unit 40 shown in FIG. 1 by executing the set value reflecting process 68. The CPU 52 operates as the set value receiving unit 42 shown in FIG. 1 by executing the set value receiving process 70. The CPU 52 operates as the control unit 44 illustrated in FIG. 1 by executing the control process 72. The CPU 52 operates as the processing unit 48 illustrated in FIG. 1 by executing the processing process 74. A set value storage area 76 is provided in the storage area of the storage unit 56, and the set value storage area 76 functions as the set value storage unit 46.

  As a result, the computer 50 that has executed the encoder control program 62 functions as the encoder control unit 34. The encoder control program 62 is an example of a video storage / delivery program according to the disclosed technology. Further, the computer 50 can be realized by, for example, a semiconductor integrated circuit, more specifically, an ASIC (Application Specific Integrated Circuit) or the like.

  Next, the operation of the present embodiment will be described. First, a pre-setting process executed when setting information is input via the setting PC 80 in a state where the setting PC 80 is connected to the connector 78 will be described with reference to FIG. Will be described with reference to FIG.

  In step 100 of the pre-setting process, the trigger activation time is set via the setting PC 80. The trigger activation time is the time to determine whether the video change amount exceeds the protection start threshold after acquiring the earthquake early warning signal from the earthquake early warning system, and the time is set to several seconds to several tens of seconds. Is done. The trigger activation time set via the setting PC 80 is received by the setting value receiving unit 42, and the setting value receiving unit 42 causes the setting value storage unit 46 to store the received trigger activation time.

  In step 102, the protection start threshold value, the protection end threshold value, and the stop determination time are set via the setting PC 80. The protection start threshold is a threshold for determining the start of protection of video data, and the protection end threshold and the stop determination time are thresholds for determining the end of video data to be protected. The protection start threshold, the protection end threshold, and the stop determination time set via the setting PC 80 are received by the setting value receiving unit 42, and the setting value receiving unit 42 receives the received protection start threshold, protection end threshold, and stop determination time. Is stored in the set value storage unit 46. The protection start threshold is an example of the first threshold of the disclosed technique, the protection end threshold is an example of the second threshold of the disclosed technique, and the stop determination time is an example of a predetermined time of the disclosed technique.

  In step 104, the time until automatic opening is set via the setting PC 80. The time until automatic release is the time from the start of protection of video data to be protected until the protection is released (terminated). The time until automatic opening set via the setting PC 80 is received by the setting value receiving unit 42, and the setting value receiving unit 42 causes the setting value storage unit 46 to store the received time until automatic opening. For example, a time of about 24 hours is set as the time until the automatic opening.

  In step 106, the retroactive time is set via the setting PC 80. The retroactive time is a time that defines how far video data is to be protected with respect to the timing at which the video data protection is started. The retroactive time set via the setting PC 80 is received by the set value receiving unit 42, and the set value receiving unit 42 causes the set value storage unit 46 to store the received retroactive time. In this embodiment, the setting of the retroactive time is arbitrary, and the retroactive time setting is omitted when the retroactive video data to be protected is unnecessary. If the retroactive time setting is omitted, the retroactive time defaults to zero. When the retroactive time is set, the retroactive time is set to a time of about 5 minutes to 10 minutes.

  In step 108, the disaster protection rate is set via the setting PC 80. The disaster protection rate is an encoding rate of video data to be protected at the time of disaster. The disaster protection rate set via the setting PC 80 is received by the setting value receiving unit 42, and the setting value receiving unit 42 causes the setting value storage unit 46 to store the received disaster protection rate. In this embodiment, the setting of the disaster protection rate is arbitrary, and when the disaster protection rate setting is unnecessary, the setting of the disaster protection rate is omitted. When the setting of the disaster protection rate is omitted, the video data to be protected at the time of the disaster is set to the same encoding rate as the video data not to be protected.

  In step 110, the setting for turning on and off the automatic optimization of the coding rate is performed via the setting PC 80. The automatic coding rate optimization function allows video data for a predetermined time set in advance as video data not to be protected to be stored in a state where video data to be protected is stored in the storage unit 30. In addition, this is a function for optimizing the encoding rate of video data that is not protected. The on / off setting of the automatic optimization function of the coding rate set via the setting PC 80 is received by the setting value receiving unit 42, and the setting value receiving unit 42 sets the on / off setting of the automatic optimization function of the received coding rate. Is stored in the set value storage unit 46.

  When the process of step 110 is finished, the pre-setting process is finished. When the pre-setting process is finished, the connection between the connector 78 and the setting PC 80 is also released.

  Next, storage of video data in the storage unit 30 in a state where no earthquake has occurred will be described. As shown in FIG. 5, in the present embodiment, video data that is not protected is stored in the storage unit 30 as a pointer (WRT_ST) that points to the start address of the storage area of video data that is not protected and the storage area. It is managed by a pointer (WRT_ED) that points to the end address of. Then, in a state in which no video data is stored in the storage unit 30, the pointer WRT_ST and the pointer WRT_ED indicate the head address (0) of the storage space of the storage unit 30 as shown in FIG.

  When encoded video data is generated when the encoder 14 is connected to the video imaging unit 12 and a video signal is input from the video imaging unit 12, the processing unit 48 stores the video data from the position indicated by the pointer WRT_ED. And the pointer WRT_ED is updated (see FIG. 5B). The storage of the video data in the storage unit 30 and the update of the pointer WRT_ED are repeated until the pointer WRT_ED indicates a state (refer to FIG. 5C) indicating the end address (FFFF) of the storage space of the storage unit 30.

  When the pointer WRT_ED enters a state (see FIG. 5C) indicating the end address (FFFF) of the storage space of the storage unit 30, the storage unit 30 is in a state where video data is stored in the entire area of the storage space. For this reason, first, the pointer WRT_ED is returned to the top address (0) of the storage space of the storage unit 30, the video data is stored from the position indicated by the pointer WRT_ED, and the pointer WRT_ST and the pointer WRT_ED are updated respectively (FIG. 5D). reference). As a result, the video data stored in the storage unit 30 is overwritten with the new video data in the oldest order, and the video data is cyclically overwritten and stored in the storage unit 30.

  By the way, when an earthquake occurs and the trigger acquisition unit 36 acquires the emergency earthquake warning signal transmitted from the emergency earthquake warning system 20, the video protection process shown in FIG.

  In step 120 of the video protection process, the trigger acquisition unit 36 acquires the number of distributions of video data from the main encoder and sub-encoder to the operation PC of the video utilization system 18, and the number of distributions of the acquired video data becomes zero. It is determined whether or not. If the determination in step 120 is negative, since the video utilization system 18 is in a state where the video can be acquired from the encoder 14, the video protection process is terminated.

  If the determination in step 120 is affirmed, it can be determined that the communication between the encoder 14 and the video utilization system 18 has been interrupted, and that this communication disruption may be due to an earthquake. Therefore, if the determination in step 120 is affirmed, the control unit 44 is notified that the number of distributions of video data from the main encoder and sub-encoder to the operation PC of the video utilization system 18 has become zero. 122.

  On the other hand, the video change amount acquisition unit 38 acquires the change amount of the video represented by the video data, and notifies the control unit 44 of the acquired video change amount. In the next step 122, the control unit 44 sets the protection start threshold in which the video change amount notified from the video change amount acquisition unit 38 is set in the pre-setting process within the trigger activation time set in the pre-setting process. It is determined whether it has been exceeded. If the determination in step 122 is negative, the occurrence of an earthquake is notified and communication between the encoder 14 and the video utilization system 18 is interrupted, but the image shooting unit 12 is almost shaken due to the earthquake. It can be judged that it is not. Therefore, if the determination at step 122 is negative, the video protection process is terminated.

  If the determination in step 122 is affirmed, the occurrence of an earthquake is notified, communication between the encoder 14 and the video utilization system 18 is interrupted, and the installation location of the video photographing unit 12 also shakes due to the earthquake. Therefore, it can be determined that video data should be protected. If the determination in step 122 is affirmed, the control unit 44 requests the processing unit 48 to start protecting the video data (see also the timing of “protection data start” in FIG. 6), and proceeds to step 124.

  When the controller 44 requests the video data to be protected, in step 124, the processing unit 48 determines whether or not a disaster protection rate is set and stored in the set value storage unit 46. If the determination in step 124 is affirmative, the process proceeds to step 126, and in step 126, the processing unit 48 sets a disaster protection rate in the main encoder (video / audio signal encoding unit 24A). As a result, the main encoder performs encoding at the disaster protection rate. If the determination in step 124 is negative, step 126 is skipped.

  In step 128, the processing unit 48 first confirms the retroactive time stored in the set value storage unit 46. As the video protection start time, if the set retroactive time is 0, the current time is traced. If the set retroactive time is greater than 0, the current retroactive time is traced back. The set time is set in the set value storage unit 46. Here, the information set in the set value storage unit 46 is reflected in the main body of the encoder 14 by the set value reflecting unit 40, so that the video data stored in the storage unit 30 thereafter (or the retroactive time from the current time). Video data including a certain period) is treated as protection data to be protected.

  Specifically, for example, in the state shown in FIG. 5D, a pointer (PRT_ST) indicating the start address of the storage area of the video data to be protected and a pointer (PRT_ED) indicating the end address of the storage area are set (FIG. 5D). FIG. 5 (E)). Then, when encoded video data to be protected is generated by inputting a video signal from the video shooting unit 12, the processing unit 48 stores the video data from the position indicated by the pointer PRT_ED and also stores the pointer PRT_ED and the pointer. WRT_ST is updated (see FIG. 5F).

  When the retroactive time is greater than 0, for example, in the state shown in FIG. 5D, the pointer WRT_ED is returned by the retroactive time, the pointer PRT_ST is made to coincide with the pointer WRT_ED, and the pointer PRT_ED is set to the pointer WRT_ST. Match (see FIG. 5G). As a result, video data in a period that is traced back from the current time by the retroactive time is incorporated into the protection target.

  In the next step 130, the control unit 44 satisfies the setting condition for the end of the protection period, that is, the condition that the state in which the video change amount notified from the video change amount acquisition unit 38 is equal to or less than the protection end threshold continues for the stop determination time. Determine whether or not. If the determination in step 130 is negative, step 130 is repeated until the determination in step 130 is positive. During this time, the encoded video data is stored in the storage unit 30 as video data to be protected.

  If the setting condition for the protection period end is satisfied (see also the timing of “protection data end” shown in FIG. 6), the determination in step 130 is affirmed, and the control unit 44 determines the end of the video data to be protected. Request 48 and go to step 132. In step 132, when the control unit 44 requests the video data protection end, the processing unit 48 sets the video data protection end time in the setting value storage unit 46, and requests the setting value reflection unit 40 to reflect the information. To do. Thereby, the storage of the video data to be protected ends.

  In the subsequent storage of video data in the storage unit 30, when the pointer WRT_ED reaches the pointer PRT_ST, the pointer WRT_ED is updated so as to match the pointer PRT_ED. Thereby, the subsequent overwriting storage of the video data in the storage unit 30 is performed in an area other than the protection area with the pointer PRT_ST at the head and the pointer WRT_ED at the end, and the video data to be protected stored in the protection area is It is prevented from being overwritten by video data that is not protected.

  In the next step 134, the processing unit 48 refers to the setting value storage unit 46 and determines whether or not the automatic coding rate optimization function is turned on. When the determination in step 134 is affirmed, the process proceeds to step 136, and in step 136, the processing unit 48 calculates the storage capacity of the overwrite storage area that is reduced as the protection data is stored in the storage unit 30.

  In the next step 138, the processing unit 48 performs overwriting storage with a reduced storage capacity when the time of the video data when the video data of the normal encoding rate is stored in all storage areas of the storage unit 30 is T. A coding rate for storing video data of time T in the area is calculated. The above encoding rate can be obtained by calculating M ÷ T, where M is the storage capacity of the overwrite storage area where the storage capacity has decreased. Then, the processing unit 48 sets the calculated encoding rate in the main encoder, and proceeds to step 140.

  Thus, the main encoder performs encoding at the set encoding rate, and the video data of the same time T as before the storage capacity is reduced can be stored in the overwrite storage area where the storage capacity is reduced. Since the movement of the subject is small in a fixed point camera or the like, even if the encoding rate is lowered as described above, the influence on the image quality is suppressed to the minimum. If the determination at step 134 is negative, steps 136 and 138 are skipped and the routine proceeds to step 140.

  In the next step 140, the processing unit 48 starts circular overwrite storage of video data in the overwrite storage area whose storage capacity has decreased. Thus, the video data stored in the overwrite storage area of the storage unit 30 is overwritten with the new video data in the oldest order, and the video data is cyclically overwritten and stored in the overwrite storage area of the storage unit 30 (FIG. 5). (See also (H)).

  As an example, FIG. 7 shows the state of the video data stored in the storage unit 30 when an earthquake occurs at 0:00, the aftershock ends at 1:00, and communication is restored at 6:00. An example is shown. When the video data to be protected is not protected as in the present embodiment, as shown in FIG. 7 as “current state (no function)”, 8 hours have passed since the occurrence of the earthquake at 8:00. At the time, the video data of the earthquake occurrence period (0:00 to 1:00) is overwritten. On the other hand, when the video data to be protected as in the present embodiment is protected, as shown in FIG. 7 as “with function (with retroactive)” and “with function (without retroactive)”, Even at 00 minutes, video data of the earthquake occurrence period (0:00 to 1:00) is stored.

  In the next step 142, the processing unit 48 refers to the time until the automatic release stored in the set value storage unit 46, and whether the time until the automatic release has elapsed or has been instructed to open the protection area manually. Judge whether or not. If the determination in step 142 is negative, step 142 is repeated until the determination is positive. The manual release of the protection area is instructed when communication between the encoder 14 and the video use system 18 is recovered and video data to be protected is transferred from the encoder 14 to the video use system 18. Is done. Further, even after the video data to be protected is transferred from the encoder 14 to the video utilization system 18, even if there is no instruction to release the protected area, the determination in step 142 is affirmed because the time until the automatic release has elapsed. Is done.

  If the determination in step 142 is affirmed, the process proceeds to step 144. In step 144, the processing unit 48 releases the protection area (see also “after 24 hours” shown in FIG. 7), and ends the video protection process.

  In the present embodiment, as described above, from the first time point when the video change amount exceeds the protection start threshold value, to the second time point when the video change amount is equal to or less than the protection end threshold value. The video data input during this period is excluded from overwriting and stored in the storage unit. This prevents the video data to be protected from being overwritten and deleted even if a certain amount of time has passed since the occurrence of the earthquake, and protects important video such as when an earthquake occurs from being overwritten. it can.

  Further, in the present embodiment, when the change amount of the video exceeds the protection start threshold and communication interruption with the operation PC of the video usage system 18 is detected (distribution of video data from the main encoder and the sub encoder to the operation PC). Video data is protected when the number is 0). As a result, unnecessary video data protection is performed when communication with the operation PC is not interrupted, that is, when the operation PC is in a state in which an image can be acquired such as when an earthquake occurs. It is possible to prevent the storage capacity of the storage unit 30 from being compressed.

  In the present embodiment, when the change amount of the video exceeds the protection start threshold, the communication interruption with the operation PC of the video utilization system 18 is detected, and the emergency earthquake warning signal is acquired by the trigger acquisition unit 36. Video data is protected. Thereby, the image | video at the time of an earthquake occurrence can be protected reliably.

  Furthermore, in this embodiment, the retroactive time can be set, and when the retroactive time is set, the video data of the period from the timing retroactive by the set retroactive time to the time of the earthquake is also obtained. Protected. Thereby, it becomes possible to add the video data of the period before the occurrence of the earthquake to the protection target.

  In the present embodiment, the disaster protection rate can be set. When the disaster protection rate is set, the video data to be protected is encoded according to the disaster protection rate. This makes it possible to save important video data such as when an earthquake occurs as video data encoded at a desired encoding rate.

  Although the emergency earthquake warning signal has been described above as an example of the emergency signal in the disclosed technology, the disclosed technology is not limited to this, and the emergency signal is, for example, another signal such as a tsunami warning signal. May be.

  In the above description, the encoder control program 62, which is an example of the video storage / delivery program according to the disclosed technology, has been previously stored (installed) in the storage unit 56 of the encoder 14, but is not limited thereto. Absent. The video storage / delivery program according to the disclosed technology can be provided in a form recorded in a recording medium such as a CD-ROM or a DVD-ROM.

  All documents, patent applications and technical standards mentioned in this specification are to the same extent as if each individual document, patent application and technical standard were specifically and individually stated to be incorporated by reference. Incorporated by reference in the book.

  Regarding the above embodiment, the following additional notes are disclosed.

(Appendix 1)
A processing unit that cyclically overwrites and stores sequentially input video data in the storage unit;
A video change amount acquisition unit for acquiring a change amount of a video represented by the video data;
From the first time point when the change amount of the image acquired by the image change amount acquisition unit exceeds the first threshold value, the state where the change amount of the image is less than the second threshold value that is smaller than the first threshold value continues for a predetermined time or more. A control unit that controls to exclude video data input during the period up to the second time point from being overwritten;
Video storage and distribution device.

(Appendix 2)
A detector that detects a state of communication with an external device that receives the video data from the device;
The control unit is defined as the first time point when the change amount of the video acquired by the video change amount acquisition unit exceeds a first threshold and the detection unit detects a disconnection of communication with the external device. The video storage / delivery device according to appendix 1.

(Appendix 3)
A first encoding unit that encodes sequentially input video data at a first encoding rate, and encodes sequentially input video data at a second encoding rate lower than the first encoding rate. And a second encoding unit,
The detection unit, when the distribution of the video data from the first encoding unit to the external device is interrupted, and when the distribution of the video data from the second encoding unit to the external device is interrupted, The video storage / delivery device according to supplementary note 2, wherein the video storage / delivery device detects that communication with the external device has been interrupted.

(Appendix 4)
An emergency signal acquisition unit for acquiring an emergency signal;
The control unit is configured such that the change amount of the video acquired by the video change amount acquisition unit exceeds a first threshold, and the detection unit detects a disconnection of communication with the external device, and the emergency signal acquisition unit The video accumulation / delivery device according to supplementary note 2, wherein the time point when the emergency signal is acquired is the first time point.

(Appendix 5)
The control unit excludes the video data input during a period from the third time point to the second time point, which is a predetermined time before the first time point, from the overwriting target and stores the video data in the storage unit. 5. The video storage / delivery device according to any one of 1 to 4.

(Appendix 6)
An encoding unit for encoding sequentially input video data;
The processing unit stores the video data encoded by the encoding unit in a storage unit,
When the control unit excludes the video data from being overwritten and stores the video data in the storage unit, the control unit sets the encoding unit so that the video data is encoded at a preset emergency encoding rate. The video storage / delivery device according to any one of Supplementary Notes 1 to 5, which is controlled.

(Appendix 7)
A photographing device that outputs video data;
The video storage / delivery device according to any one of claims 1 to 6,
An external device that receives the video data from the video storage and delivery device;
Video storage and delivery system including

(Appendix 8)
The video data that is input sequentially is overwritten and stored in the storage unit,
Obtaining the amount of change in the video represented by the video data;
The period from the first time point when the obtained change amount of the video exceeds the first threshold to the second time point when the state where the change amount of the video is equal to or less than the second threshold value, which is smaller than the first threshold value, continues for a predetermined time or more. A video storage / delivery method that includes controlling input video data to be excluded from being overwritten.

(Appendix 9)
The video accumulation / delivery method according to supplementary note 8, wherein the time point when the change amount of the acquired video exceeds the first threshold value and the interruption of communication with the external device is detected is the first time point.

(Appendix 10)
Encoding sequentially input video data at a first encoding rate and encoding sequentially input video data at a second encoding rate lower than the first encoding rate;
Distribution of the video data encoded at the first encoding rate to the external device is interrupted, and distribution of the video data encoded at the second encoding rate to the external device is interrupted. The video storage / delivery method according to appendix 9, wherein communication with the external device is detected to be interrupted.

(Appendix 11)
The video accumulation / delivery method according to supplementary note 9, wherein the time point when the change amount of the acquired video exceeds the first threshold, the communication interruption with the external device is detected, and the emergency signal is acquired is the first time point.

(Appendix 12)
Appendices 9 to 11 that exclude the video data input during a period from the third time point to the second time point, which is a predetermined time before the first time point, from being overwritten and stored in the storage unit The video accumulation / delivery method according to claim 1.

(Appendix 13)
Encode sequentially input video data,
Store the encoded video data in the storage unit,
Any one of appendix 9 to appendix 12, wherein the video data is controlled to be encoded at a preset emergency encoding rate when the video data is excluded from being overwritten and stored in the storage unit. The video accumulation and delivery method according to claim 1.

(Appendix 14)
On the computer,
The video data that is input sequentially is overwritten and stored in the storage unit,
Obtaining the amount of change in the video represented by the video data;
The period from the first time point when the obtained change amount of the video exceeds the first threshold to the second time point when the state where the change amount of the video is equal to or less than the second threshold value, which is smaller than the first threshold value, continues for a predetermined time or more. A video accumulation / delivery program for performing processing including control to exclude input video data from being overwritten.

DESCRIPTION OF SYMBOLS 10 Image | video storage delivery system 12 Image | video imaging | photography part 14 Encoder 16 Network 18 Image | video utilization system 20 Emergency earthquake early warning system 24A, 24B Video / audio signal encoding part 30 Memory | storage part 34 Encoder control part 36 Trigger acquisition part 38 Image | video change amount acquisition part 40 Setting value reflecting unit 42 Setting value receiving unit 44 Control unit 46 Setting value storing unit 48 Processing unit 50 Computer 52 CPU
54 Memory 56 Storage Unit 62 Encoder Control Program

Claims (9)

A processing unit that cyclically overwrites and stores sequentially input video data in the storage unit;
A video change amount acquisition unit for acquiring a change amount of a video represented by the video data;
From the first time point when the change amount of the image acquired by the image change amount acquisition unit exceeds the first threshold value, the state where the change amount of the image is less than the second threshold value that is smaller than the first threshold value continues for a predetermined time or more. A control unit that controls to exclude video data input during the period up to the second time point from being overwritten;
Video storage and distribution device. A detector that detects a state of communication with an external device that receives the video data from the device;
The control unit is defined as the first time point when the change amount of the video acquired by the video change amount acquisition unit exceeds a first threshold and the detection unit detects a disconnection of communication with the external device. The video storage / delivery device according to claim 1. A first encoding unit that encodes sequentially input video data at a first encoding rate, and encodes sequentially input video data at a second encoding rate lower than the first encoding rate. And a second encoding unit,
The detection unit, when the distribution of the video data from the first encoding unit to the external device is interrupted, and when the distribution of the video data from the second encoding unit to the external device is interrupted, The video storage / delivery device according to claim 2, wherein communication with the external device is detected to be interrupted. An emergency signal acquisition unit for acquiring an emergency signal;
The control unit is configured such that the change amount of the video acquired by the video change amount acquisition unit exceeds a first threshold, and the detection unit detects a disconnection of communication with the external device, and the emergency signal acquisition unit The video accumulation / delivery device according to claim 2, wherein the time point when the emergency signal is acquired is set as the first time point.   The control unit excludes the video data input during a period from a third time point to a second time point, which is a predetermined time before the first time point, from being overwritten, and stores the video data in the storage unit. The video storage / delivery device according to any one of claims 1 to 4. An encoding unit for encoding sequentially input video data;
The processing unit stores the video data encoded by the encoding unit in a storage unit,
When the control unit excludes the video data from being overwritten and stores the video data in the storage unit, the control unit sets the encoding unit so that the video data is encoded at a preset emergency encoding rate. 6. The video storage / delivery device according to claim 1, wherein the video storage / delivery device is controlled. A photographing device that outputs video data;
The video storage / delivery device according to any one of claims 1 to 6,
An external device that receives the video data from the video storage and delivery device;
Video storage and delivery system including The video data that is input sequentially is overwritten and stored in the storage unit,
Obtaining the amount of change in the video represented by the video data;
The period from the first time point when the obtained change amount of the video exceeds the first threshold to the second time point when the state where the change amount of the video is equal to or less than the second threshold value, which is smaller than the first threshold value, continues for a predetermined time or more. A video storage / delivery method that includes controlling input video data to be excluded from being overwritten. On the computer,
The video data that is input sequentially is overwritten and stored in the storage unit,
Obtaining the amount of change in the video represented by the video data;
The period from the first time point when the obtained change amount of the video exceeds the first threshold to the second time point when the state where the change amount of the video is equal to or less than the second threshold value, which is smaller than the first threshold value, continues for a predetermined time or more. A video accumulation / delivery program for performing processing including control to exclude input video data from being overwritten.