JP4860958B2 - Video transmission device having active and standby systems - Google Patents

Description

  The present invention relates to a video transmission apparatus having an active system and a standby system, which has an active system and a standby system, and outputs an output by switching to the standby system when an abnormality occurs in the active system.

  In a video transmission device that converts various moving image materials composed of digital video signals into compressed data, stores them in a data storage device (data bank) such as a hard disk, and reads and decompresses and decodes them in the necessary order when necessary. In order to improve reliability, an active system and a standby system are provided, and when an abnormality occurs in the active system, the system is switched to the standby system and output.

  FIG. 8 is a block diagram showing an example of the configuration of a conventional video transmission apparatus having an active system and a standby system (not related to the literature known invention).

  Various moving image materials composed of digital video signals are converted into compressed data by the encoder 1 and distributed to the active system A and the standby system B.

  The active system A includes a data storage device (data bank) 2a such as a hard disk and a decoder 3a connected to the data storage device (data bank) 2a, and the active system B includes a data storage device (data bank) 2b such as a hard disk and data storage. It comprises a decoder 3b connected to a device (data bank) 2b.

  Although the output of the decoder 3a and the output of the decoder 3b are connected to the switch 4, the switch 4 is normally switched to the output of the decoder 3a of the working system A, and the output of the decoder 3a of the working system A is shown in FIG. Although not shown, it is output to the transmitter at the subsequent stage, and a digital video signal is transmitted from the transmitter to the television receiver in each home.

  If an abnormality occurs in the active system A due to a malfunction of the video transmission device that occurs rarely, the output of the decoder 3a of the active system A is a still image (hereinafter referred to as a freeze image) as it is immediately before the abnormality occurs. It becomes. Although not shown, by connecting a monitor to the output of the decoder 3a of the active system A, a person can recognize that it is a freeze image by looking at the screen of the monitor.

  When it is recognized that an abnormality has occurred in the active system A, the output of the decoder 3b of the standby system B is output to the subsequent transmitter by manually switching the switch 4.

  For example, Patent Document 1 discloses a video transmission apparatus having an active system and a standby system, which has an active system and a standby system, and outputs an output by switching to the standby system when an abnormality occurs in the active system.

JP 2004-64255 A

  However, when an abnormality occurs in the working system, the system is manually switched to the standby system, so that it takes 3 to 5 seconds to switch.

  An object of the present invention is to provide a video transmission apparatus having an active system and a standby system, which can quickly switch to a standby system when an abnormality occurs in the active system.

  According to the present invention, in a video transmission device having an active system and at least one standby system, a digital video signal is distributed to the active system and the standby system, and pixel levels of all pixels of each video frame in the decoded output of the active system The image data amount that is the sum of the values is calculated, and when there is no change in the image data amount of each video frame, the image data amount is switched to the spare system and output.

  Further, the present invention provides a video transmission apparatus having an active system and at least one standby system, wherein a digital video signal is distributed to the active system and the standby system, and each video in the decoded output of both the active system and the standby system When the amount of image data of a frame is calculated, and there is no change in the amount of image data of each video frame in the decoded output of the active system, and there is a change in the amount of image data of each video frame in the decoded output of the standby system The output is switched to the standby system.

  According to the present invention, in a video transmission device having an active system and at least one standby system, a digital video signal is changed from a video level at a specific location of each video frame for each video frame before the active system and the Distributing to the standby system, calculating the image data amount of each video frame in the decoded output of both the active system and the standby system, and there is no change in the image data amount of each video frame in the decoded output of the active system, and When there is a change in the amount of image data of each video frame in the decoding output of the standby system, it is switched to the standby system and output.

  According to the present invention, it is possible to obtain a video transmission apparatus having an active system and a standby system that can promptly switch to a standby system when an abnormality occurs in the active system.

  An embodiment of a video transmission apparatus having an active system and a standby system according to the present invention will be described with reference to FIGS.

  FIG. 1 is a configuration diagram of an embodiment of a video transmission apparatus having an active system and a standby system according to the present invention. In FIG. 1, the same parts as those in FIG.

  In FIG. 1, a video change detector 5a is connected to the output of the active system A decoder 3a, a video change detector 5b is connected to the output of the standby system B decoder 3b, and the output and video of the video change detector 5a are connected. The output of the change detector 5b is connected to the determiner 6, and the output of the determiner 6 is connected to the switch 4. The determiner 6 controls the switch 4 when a freeze indicating an abnormality occurs in the active system. To switch to the standby system B for output.

  Here, the video change detector 5a calculates the image data amount of each video frame in the decoded output of the decoder 3a of the active system A, and a freeze occurs when it is detected that there is no change in the image data amount of each video frame. A notification signal indicating this is output. In addition, the video change detector 5b calculates the image data amount of each video frame in the decoded output of the standby system B decoder 3b, and freeze has occurred when it is detected that there is no change in the image data amount of each video frame. A notification signal indicating is output.

  FIG. 2 is a diagram showing a specific circuit example of the image change detectors 5a and 5b in FIG. In FIG. 2, the image change detectors 5 a and 5 b have the same configuration, and are configured by an integrator 21, a first memory 22, a second memory 23, a difference absolute value calculator 24, and a 0 determiner 25.

  First, the integrator 21 calculates the video data amount for one video frame. The calculated video data amount is stored in the first memory 22. When the next one video frame is input to the accumulating unit 21, the video data amount stored in the first memory 22 is stored in the second memory 23, and the video data amount of the next one video frame is stored in the accumulating unit. Calculated at 21 and stored in the first memory 22.

  The difference between the amount of video data stored in the first memory 22 and the amount of video data stored in the second memory 23 (one video frame input to the difference absolute value unit 24 and one frame before this video frame) The difference absolute value unit 24 calculates the difference between the video data amount and the video frame, and outputs the result to the 0 determination unit 25. When there is no difference, the 0 determiner 25 outputs a notification signal indicating that a freeze has occurred.

  3 and 4 are diagrams for explaining the operation of the image change detectors 5a and 5b in FIG.

  FIG. 3 shows a case where both the active system A and the standby system B in FIG. 1 are operating normally. In this case, the video frames of the active system A and the standby system B shown in FIG. Since each video frame is a moving image, the amount of image data integrated by the integrator 21 in FIG. 2 changes for each video frame in both the active system A and the standby system B as shown in FIG. This is the amount of image data. Therefore, in this case, the difference absolute value unit 24 outputs the difference in the amount of video data between one video frame and the video frame one frame before this video frame.

  On the other hand, FIG. 4 shows a case where a freeze occurs in the active system A in FIG. 1, and a freeze occurs in the third and subsequent video frames as shown in FIG. Since the video frame is a still image, the amount of image data integrated by the integrator 21 of FIG. 2 of the active system A changes for each of the third and subsequent video frames as shown in FIG. There is no fixed amount of image data. Therefore, in this case, since the difference absolute value unit 24 does not output the difference in the amount of video data between one video frame and the video frame one frame before this video frame, the 0 determination unit 25 indicates that the freeze has occurred. A notification signal is output.

  When the video change detector 5a outputs a notification signal indicating that a freeze has occurred, the determiner 6 connected to the output of the video change detector 5a and the output of the video change detector 5b shown in FIG. In response to the notification signal, a switching signal is output, and the switch 4 is switched from the active system A to the standby system B by the switching signal, and the output of the decoder 3b of the standby system B is output.

  Therefore, according to the present embodiment, it is possible to obtain a video transmission apparatus having an active system and a standby system that can promptly switch to the standby system when an abnormality occurs in the active system.

  Further, when the video change detector 5a outputs a notification signal indicating that a freeze has occurred, a determination device connected to the output of the video change detector 5a and the output of the video change detector 5b shown in FIG. 6 may perform processing different from the above.

  That is, when the video change detector 5a outputs a notification signal indicating that a freeze has occurred, the determiner 6 outputs a notification signal indicating that the video change detector 5b of the standby system B has generated a freeze. The switching signal in response to the notification signal is confirmed after confirming that it is normal where the notification signal is not output, that is, where there is a change in the image data amount of each video frame of the standby system B. The switch 4 is switched from the active system A to the standby system B by the switching signal, and the output of the decoder 3b of the standby system B is output.

  In the case where both the active system A and the standby system B output a notification signal indicating that the freeze has occurred, when the various moving image materials themselves composed of the digital video signals that are the inputs of FIG. 1 are video signals of a certain level It is better not to switch.

  According to this processing, it is possible to obtain a video transmission apparatus having an active system and a standby system that can effectively switch from the active system to the standby system when a freeze indicating an abnormality occurs in the active system. it can.

  FIG. 5 is a configuration diagram of another embodiment of a video transmission apparatus having an active system and a standby system according to the present invention. In FIG. 1, the same parts as those in FIG.

  In the present embodiment, various moving image materials composed of input digital video signals are distributed to the active system and the standby system after changing the video level of a specific portion of each video frame for each video frame. It is to have done.

  In FIG. 5, a pre-processor 7 is provided in the preceding stage of the encoder 1, and the pre-processor 7 receives various moving image materials composed of input digital video signals, and sets the video level at a specific position of each video frame. In other words, after pre-processing having been changed every time, the current system A and the standby system B are distributed.

  FIG. 6 is a diagram for explaining a specific preprocessing example in the preprocessor 7 of FIG. The preprocessor 7 performs a process of alternately increasing or decreasing the video level of one pixel 61a, 61b, 61c, 61d at the four corners of one frame 61 for each frame.

  As described above, when the video change detector 5a outputs a notification signal indicating that the freeze has occurred, that is, when the amount of image data is not changed, the determiner 6 determines that the video change detector 5b of the standby system B However, it does not output a notification signal indicating that the freeze has occurred, that is, after confirming that the amount of image data has changed, outputs a switching signal in response to the notification signal, and switches the switch 4 from the active system A by the switching signal. The system is switched to the system B and the output of the standby system B decoder 3b is output.

  FIG. 7 is a diagram showing the operation logic of the configuration of FIG.

  In the case of the image data amount 1 (state 1), there is a change in the working system A. In this case, the operation of the working system A is normal. Therefore, switching is not necessary and switching is not performed.

  Further, even when various moving image materials themselves composed of input digital video signals are video signals of a certain level, the amount of image data integrated by the integrator 21 in FIG. For each video frame, 1004 pixels and 996 pixels are the amount of repetitive image data, and this corresponds to a case where there is a change in the working system A. In this case, the operation of the working system A is normal and switching is not necessary or not. , Do not switch.

  In the image data amount 2 (state 2), there is no change in both the active system A and the standby system B. In this case, various moving image materials themselves consisting of input digital video signals are 1000 for each video frame. The pixel has a repetitive amount of image data. In this case, since the still image is output, it is considered that the operation of the active system A is normal, whether or not switching is necessary, and switching is not performed.

  In the image data amount 3 (state 3), the working system A has no change and the working system B has a change. In this case, when the working system A is frozen, the operation of the working system A is abnormal. Since the necessity of switching is necessary, the determination unit 6 outputs a switching signal, switches the switching unit 4 from the active system A to the standby system B by the switching signal, and outputs the output of the decoder 3b of the standby system B.

  According to the present embodiment, when the various moving image materials consisting of the input digital video signals themselves are video signals of a certain level, the current system is not switched from the current system A to the standby system B. It is possible to obtain a video transmission apparatus having an active system and a standby system that can be switched from the active system A to the standby system B when a freeze occurs in A.

  Another processing method is to calculate the amount of image data for each video frame in the decoded output of the active system, and to check whether there is an audio output of each video frame in the decoded output of the active system, and freeze if there is no audio output. In this case, by outputting a switching signal in response to the notification signal, the switch 4 is switched from the active system A to the standby system B by the switching signal, and the output of the decoder 3b of the standby system B is output. It is also possible to do.

1 is a configuration diagram of an embodiment of a video transmission apparatus having an active system and a standby system according to the present invention. FIG. It is a figure which shows the specific circuit example of the image | video change detector in FIG. It is a figure explaining operation | movement of the image | video change detector of FIG. It is a figure explaining operation | movement of the image | video change detector of FIG. It is a block diagram of other embodiment of the image | video transmission apparatus which has an active system and a backup system of this invention. It is a figure explaining the example of a specific pre-process in the pre-processor of FIG. It is a figure which shows the operation | movement logic of the structure of FIG. It is a block diagram which shows the example of a structure of the video transmission apparatus which has the conventional active system and standby system.

Explanation of symbols

  1: Encoder, 2a, 2b: Data storage unit (data bank), 3a, 3b: Decoder, 4: Switcher, 5a, 5b: Video change detector, 6: Determinator, 7: Preprocessor, 21: Integration 22: first memory, 23: second memory, 24: difference absolute value unit, 25: 0 determiner, 61: 1 frame, 61a, 61b, 61c, 61d: one pixel at the four corners of the frame.

Claims (1)

In a video transmission apparatus having an active system and at least one standby system, a process of increasing or decreasing the video level of one pixel at the four corners of each video frame alternately by 1 bit for each video frame. And then distributing to the active system and the standby system, calculating the image data amount of each video frame in the decoded output of both the active system and the standby system, and the image of each video frame in the decoded output of the active system When there is no change in the data amount and there is a change in the image data amount of each video frame in the decoding output of the standby system, the active system and the standby system are switched and output to the standby system Video transmission device.

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