JP2010213119A - Video transmission system, imaging apparatus and monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a video transmission system in which high-quality video images can be switched in an intended timing even when a high-quality video image switching operation is performed in a prescribed timing while monitoring a plurality of low-quality video images over a network at all the time, the video transmission system being configured to selectively switch video images by monitoring video images of a plurality of cameras over the network. <P>SOLUTION: A delay means at the side of an imaging unit is caused to perform delay just for at least a time tα approximately equal to a total time tn of compression and expansion processing times t1, t3 for video images at a low bit rate and uplink and downlink transmission delays t2, t4 on a network, and high-quality video images are switched on the basis of a time code. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a video transmission system that monitors video from a plurality of cameras via a network and selectively switches the video.

  2. Description of the Related Art Conventionally, as a technique for transmitting images captured by a plurality of camera units to a monitor display device, a monitor recording device, or the like via a network such as a LAN (local area network) or the Internet, images captured by a camera unit A monitor composed of two or more surveillance camera terminals that compress and encode the video and send it to the network, and two or more surveillance video recording devices that receive and record video data sent from the surveillance camera terminal via the network A system is known (for example, refer to Patent Document 1).

JP 2008-09884 A

  In the monitoring system as disclosed in Patent Document 1, the transmission capacity of video data is limited in a network in which a monitoring camera terminal and a monitoring video recording apparatus are spread over remote locations. In this way, in a surveillance system that transmits video (high-quality video) and semi-video (low-quality video) over a network with limited transmission capacity, the network bandwidth allocation can be changed according to the emergency, In general, systems that aim to avoid network congestion are being used so that video (high-quality video) can be monitored in an emergency by changing the compression rate.

  However, for example, if a video (high-quality video) is switched in a certain scene while monitoring semi-videos (low-quality video) from multiple camera units via a network at all times, (High-quality video) has a problem that the video is switched after the intended timing.

  The present invention has been made in order to solve the above problems, and an object of the present invention is to monitor a video from a plurality of cameras via a network and selectively switch the video. Provides a video transmission system that enables high-quality video to be switched at the intended timing even when a high-quality video is switched at a predetermined timing while constantly monitoring multiple low-quality videos via the network There is to do.

A video transmission system according to the present invention is a video transmission system comprising an imaging device capable of transmitting captured video data and a monitor device capable of receiving the video data generated by the imaging device via a network,
a) The imaging device comprises:
Interface means for communicating with the monitor device via the network;
A plurality of imaging means, a first encoding means that is provided for each imaging means and encodes video data captured by the imaging means at a low bit rate, and each of the video data captured by each imaging means is delayed by a predetermined time. Delay means, a plurality of video data input from the delay means, one of the inputted plurality of video data is selected and output, and the video data output by the switching means is at a high bit rate. Video data encoded by the first and second encoding means is transmitted to the monitor device via the interface means, including second encoding means for encoding and control means for controlling the operation of the switching means. ,
b) The monitor device
Interface means for communicating with the imaging apparatus via a network; and first decoding for decoding a plurality of video data encoded by the first encoding means received from the imaging apparatus via the interface means Means, a plurality of display means for displaying each of the video data decoded by the first decoding means, and the video encoded by the second encoding means received from the imaging device via the interface means Second decoding means for decoding the data, and an operation instruction by the user to select one video from the videos displayed on the plurality of display means, and generating video data of the selected video An operation means for transmitting a switching signal indicating the imaging means to the imaging device via the interface means,
c) The control unit of the imaging device selects video data from one imaging unit indicated by the switching signal from a plurality of video data input from the delay unit based on the switching signal received from the monitor device. Then, the operation of the switching means is controlled so as to output.

The video transmission system according to the present invention is a video transmission system including an imaging device capable of transmitting captured video data and a monitor device capable of receiving the video data generated by the imaging device via a network. And
a) The imaging device comprises:
Interface means for communicating with the monitor device via a network, a plurality of imaging means for generating video data to which a time code is assigned for each video frame, and an image captured by the imaging means provided for each imaging means First encoding means for encoding data at a low bit rate, delay means for delaying each of video data picked up by each image pickup means for a predetermined time, a time code together with a switching signal via a network, and the input A switching means for switching to video data indicated by the switching signal when a video frame provided with a time code that matches the time code is input from the delay means, and the video data output by the switching means is high. Second encoding means for encoding at a bit rate, and control means for controlling the operation of the switching means, Video data encoded by the first and second encoding means is transmitted to the monitoring device via the interface means,
b) The monitor device
Interface means for communicating with an imaging device via a network; and first processing for decoding a plurality of video data received via the network and generated by a plurality of imaging means and encoded at a low bit rate. A decoding means; a plurality of display means for displaying each of the video data decoded by the first decoding means; and a time code for detecting a time code attached to the video data output from the first decoding means. Detection means; second decoding means for decoding video data generated by one of the plurality of imaging means and encoded at a high bit rate, received via the network; and time The time code information is received from the code detection means, and the time code of the video data when one video data is selected by the user is With a switching signal indicating the imaging means for generating image data of the 4-option video over the network and a operation means for transmitting to said image pickup device,
c) The switching unit of the imaging apparatus inputs a time code together with a switching signal via a network, and the switching signal indicates when a video frame to which a time code that matches the input time code is input is input. Switch to the video data to be used.

A video transmission system according to the present invention is a video transmission system comprising an imaging device capable of transmitting captured video data and a monitor device capable of receiving the video data generated by the imaging device via a network,
a) The imaging device comprises:
Interface means for communicating with the monitor device via a network, a plurality of imaging means for generating video data to which a time code is assigned for each video frame, and video data provided for each imaging means and imaged by the imaging means A first encoding unit that encodes the image data at a low bit rate, a second encoding unit that is provided for each imaging unit and encodes video data captured by the imaging unit at a high bit rate, and a second encoding unit. A delay means for delaying each of the encoded video data for a predetermined time; a plurality of video data from the delay means; a switching means for selecting and outputting one of the input video data; Control means for controlling the operation of the switching means, and the video data encoded by the first encoding means and output from the switching means Image data is transmitted to the monitoring device via the interface means,
b) The monitor device
Interface means for communicating with the image pickup apparatus via a network; and first processing for decoding a plurality of video data received via the network and generated by a plurality of image pickup means and encoded at a low bit rate. And a plurality of display means for displaying each of the video data decoded by the first decoding means, and one of the plurality of imaging means received via the network, and Second decoding means for decoding video data encoded at a high bit rate; time code detecting means for detecting a time code attached to video data output from the first decoding means; The time code of the video data when one video data is selected by the user upon receiving the time code information from the time code detection means, With the selected video switching signal indicating the imaging means for generating image data through the network and a operation means for transmitting to said image pickup device,
c) The switching unit of the imaging apparatus inputs a time code together with a switching signal via a network, and the switching signal indicates when a video frame to which a time code that matches the input time code is input is input. Switch to the video data to be used.

A video transmission system according to the present invention is a video transmission system comprising an imaging device capable of transmitting captured video data and a monitor device capable of receiving the video data generated by the imaging device via a network,
a) The imaging device comprises:
Interface means for communicating with the monitor device via a network; imaging means for generating video data to which a time code is assigned for each video frame; and encoding video data captured by the imaging means at a low bit rate. 1 encoding means, second encoding means for encoding the video data captured by the imaging means at a high bit rate, delay means for delaying the video data encoded by the second encoding means for a predetermined time, and on A switch means for sending the video data sent from the delay means to the interface means when stopped, and a switch means for stopping sending the video data sent from the delay means to the interface means when turned off; Controlling the operation of the switch means based on the switching signal received from the interface means from Control means for inputting a time code together with a switching signal from the nita device via the network, and the video data encoded by the first encoding means and the video data output from the switch means are connected via the interface means. Sent to the monitoring device,
b) The monitor device
Interface means for communicating with an imaging device via a network; and first processing for decoding a plurality of video data received via the network and generated by a plurality of imaging means and encoded at a low bit rate. A decoding means; a plurality of display means for displaying each of the video data decoded by the first decoding means; and a time code for detecting a time code given to the video data output from the first decoding means. Detection means; second decoding means for decoding video data generated by one of the plurality of imaging means and encoded at a high bit rate, received via the network; and time The time code information is received from the code detection means, and the time code of the video data when one video data is selected by the user is And a manipulation unit that transmits to the image pickup device along with the switching signal indicating the imaging means for generating image data of the 4-option video via the network,
c) When the switch signal of the imaging device designates the imaging device when the video frame to which the time code that matches the input time code is input is input based on the control of the control unit. Turns on and turns off when the switching signal does not designate the imaging device.

  The delay time in the delay means is the time required for the encoding process in the first encoder means of the imaging device, the time required for the decoding process in the first decoding means of the monitor device, and the transmission of video data from the imaging device to the monitor device. It may be set to be equal to or greater than the total time of the transmission delay time of the network required for transmission and the transmission delay time of the network required to send the video data from the monitor device to the imaging device.

  An imaging apparatus according to the present invention is an imaging apparatus capable of transmitting video data captured via a network to a monitor apparatus, an interface means for communicating with the monitor apparatus via a network, a plurality of imaging means, A first encoding unit that is provided for each imaging unit and encodes video data captured by the imaging unit at a low bit rate; a delay unit that delays each of the video data captured by each imaging unit; and a delay unit Switching means for selecting and outputting one of the inputted video data, and a second encoding for encoding the video data output by the switching means at a high bit rate Means and control means for controlling the operation of the switching means, and the video data encoded by the first and second encoding means is the interface. The control means receives the switching signal from the monitoring apparatus, and the control signal indicates one of the plurality of video data input from the delay means based on the switching signal. The operation of the switching means is controlled so as to select and output video data from the imaging means.

  An image pickup apparatus according to the present invention is an image pickup apparatus capable of transmitting video data picked up via a network to a monitor apparatus, an interface means for communicating with the monitor apparatus via the network, a plurality of image pickup means, A first encoding means provided for each means and encoding video data captured by the imaging means at a low bit rate; and a video data provided for each imaging means and captured by the imaging means for encoding at a high bit rate. A second encoding means; a delay means for delaying each of the video data encoded by the second encoding means for a predetermined time; and a plurality of pieces of video data from the delay means; A switching means for selecting and outputting one of the signals, and a control means for controlling the operation of the switching means, encoded by the first encoding means Image data and video data output from the switching unit are transmitted to the monitor device via the interface unit, and the control unit receives a switching signal from the monitoring device, and receives a plurality of signals input from the delay unit based on the switching signal. The operation of the switching means is controlled so as to select and output the video data from one imaging means indicated by the switching signal.

  The imaging means assigns a time code to each video frame of the captured video data, and the switching means inputs the time code together with the switching signal via the network, and the time code that matches the input time code is assigned. When a video frame is input, switching to video data indicated by the switching signal may be performed.

An image pickup apparatus according to the present invention is an image pickup apparatus capable of transmitting video data picked up via a network to a monitor apparatus, and includes interface means for communicating with the monitor apparatus via the network, and a time code for each video frame. An imaging unit that generates the given video data, a first encoding unit that encodes video data captured by the imaging unit at a low bit rate, and a first encoding unit that encodes video data captured by the imaging unit at a high bit rate. 2 encoding means; delay means for delaying the video data encoded by the second encoding means for a predetermined time;
A switch means for sending the video data sent from the delay means to the interface means when turned on, and a monitor means for stopping sending the video data sent from the delay means to the interface means when turned off; Control means for controlling the operation of the switch means based on the switching signal received from the device via the interface means, the control means inputs the time code together with the switching signal from the monitor device via the network, the switch means, Based on the control of the control means, when a video frame with a time code that matches the input time code is input, the video signal is turned on when the switching signal specifies the imaging device, and the switching signal is Turns off when no device is specified.

  The delay time in the delay means is the time required for the encoding process in the first encoder means of the imaging device, the time required for the decoding process in the first decoding means of the monitor device, and the transmission of video data from the imaging device to the monitor device. The transmission delay time of the network required for the transmission and the transmission delay time of the network required to send the video data from the monitor device to the imaging device may be set to be equal to or greater than the total time.

  A monitor apparatus according to the present invention is a monitor apparatus capable of receiving video data generated by a plurality of image pickup means from at least one image pickup apparatus including at least one image pickup means via a network. First decoding means for decoding a plurality of video data generated by a plurality of imaging means and encoded at a low bit rate, and the video decoded by the first decoding means Video data generated by a plurality of display means for displaying each of the data and one of the plurality of imaging means received through the network and encoded at a high bit rate is decoded. The second decoding means and an operation instruction for selecting one video from videos displayed on the plurality of display means by the user is received, and the video of the selected video A switching signal indicating the imaging means for generating over data, and an operating means for transmitting to the imaging apparatus via a network.

  The apparatus further comprises time code detecting means for detecting a time code given to the video data output from the first decoding means, and the operating means receives the time code information from the time code detecting means and receives one video by the user. The time code of the video data when the data is selected may be sent together with the switching signal.

  According to the present invention, when only one high-quality video can be monitored via the network due to the limitation of the transmission capacity of the network, an arbitrary one can be monitored while simultaneously monitoring a plurality of low-quality videos via the network. It can be acquired even with high image quality, and there is an effect that the timing for switching high-quality video can be switched without delay from the timing intended by the user.

  Hereinafter, the video transmission system of the present embodiment will be described with reference to the accompanying drawings.

Embodiment 1
1. Configuration FIG. 1 is a diagram showing a configuration of a first embodiment of a video transmission system according to the present invention. As shown in FIG. 1, in the video transmission system of the present embodiment, an imaging side unit 100 and a monitor side unit 150 are connected to a network such as a LAN (local area network), a WAN (wide area network), or the Internet. 102 is connected.

  The imaging unit 100 encodes the first imaging unit 110 and the second imaging unit 120, and the imaging data captured by the first imaging unit 110 and the second imaging unit 120 with a high compression rate, thereby generating a network. Low-quality encoders 115 and 125 to be sent to the interface unit 105, a delay unit 140 to delay the video data sent from the first imaging unit 110 and the second imaging unit 120 to the switching unit 143 after a predetermined time delay, A switching unit 143 that selects and outputs one of video data input from the first imaging unit 110 and the second imaging unit 120 input from the delay unit 140, and a control unit 130 that controls the switching unit 143. And a high-quality encoder 145 that encodes video data output from the switching unit 143 with a low compression rate and sends the encoded video data to the network interface unit 105. .

  The control unit 130 receives a switching command from the monitor-side unit 150 and controls the switching unit 143 based on the switching command. The switching command is a command for selecting (switching) an imaging unit that obtains a high-quality video, and includes information for specifying an imaging unit that obtains a high-quality video. The control unit 130 also has a function of controlling the delay time in the delay unit 140 based on the control command received from the monitor side unit 150.

  The monitor-side unit 150 is input via the network interface unit 155 and the network 102, and the images of the first imaging unit 110 and the second imaging unit 120 encoded by the low-quality encoders 115 and 125 of the imaging-side unit 100. The user operates low-quality decoders 160 and 170 that respectively decode data (low-quality video data), monitor units 165 and 175 that display video data decoded by the low-quality decoders 160 and 170, respectively. High image quality that decodes high-quality video data (video data of the first imaging unit 110 or the second imaging unit 120) input from the operation unit 180 and the high-quality encoder 145 of the imaging-side unit 100 via the network 102. And a decoder 190.

  Note that a monitor for displaying the video data of one imaging unit decoded by the high quality decoder 190 may be connected to the subsequent stage of the high quality decoder 190, or a recording device for recording the video data may be connected. Also good.

  The operation unit 180 can accept a switching operation of a high-quality image received from the imaging-side unit 100 by the user, and when this switching operation is accepted, a switching command is sent to the imaging-side unit 100 via the network 102. It is sent to the control unit 130. Further, the operation unit 180 may be provided with a function of setting a delay time in the delay unit 140 of the imaging side unit 100 and sending the setting signal to the control unit of the imaging side unit 100 via the network 102. Detailed functions will be described in detail in an operation description to be described later.

2. Operation The operation of the video transmission system according to the first embodiment configured as described above will be described. In the imaging side unit 100, the video data captured by the first imaging unit 110 and the second imaging unit 120 are encoded by the low image quality encoder units 115 and 125, and the low quality video data with a low bit rate is obtained. It is generated and sent out from the network interface unit 105. The monitor unit 150 receives low-quality video data via the network 102 via the network interface unit 155. The received low-quality video data is decoded by the low-quality decoder units 160 and 170, and the respective videos are displayed on the monitor units 165 and 175. As a result, low-quality video data captured by the first imaging unit 110 and the second imaging unit 120 is displayed on the monitor units 165 and 175.

  On the other hand, in the imaging unit 100, the video data of the first imaging unit 110 and the second imaging unit 120 are further input to the delay unit 240. The two pieces of video data input to the delay unit 240 are sent to the switching unit 143 after a predetermined time delay. When the control unit 130 receives a switching command indicating the video data to be displayed from the video data of the first imaging unit 110 or the video data of the second imaging unit 120 via the network 102, the control unit 130 switches based on the switching command. 143 is controlled. The switching unit 143 selects one of the video data of the first imaging unit 110 or the second imaging unit 120 according to the switching command, and the video data from the selected one imaging unit is input to the high-quality encoder 145. Is done. The high image quality encoder 145 encodes the video data from the selected one imaging unit. The encoded video data is sent to the monitor unit 150 via the network interface unit 105 at a high bit rate.

  In the monitor unit 150, high-quality video data from the high-quality encoder 145 is received via the network 102 via the network interface unit 155, and is decoded by the high-quality decoder 290. In addition, a monitor that displays the video data of one image pickup unit decoded by the high-quality decoder 190 at the subsequent stage of the high-quality decoder 190, a high-quality video data that is monitored by connecting a recording device, Can be recorded.

  With reference to FIG. 2, the operation when switching high-quality video will be described. FIG. 2 is a timing chart showing an operation example of the video transmission system according to the present embodiment. Here, in the video transmission system, an imaging unit that obtains high-quality video at a certain timing while constantly monitoring low-quality video captured by the first imaging unit 110 and the second imaging unit 120 via the network 102. An example of operation when the switching operation is performed will be described. In FIG. 2, the horizontal axis is a time axis, and time elapses from the left to the right toward the page.

  2A and 2B show video signals 510 and 520 of the first and second imaging units 110 and 120, respectively, which are in frame units (A1, A2... An) (B1, B2... Bn). It is shown in

  The video signal 510 of the first imaging unit 110 is encoded by the low image quality encoder 115 connected to the subsequent stage. Similarly, the video signal 520 of the second imaging unit 120 is also connected to the subsequent stage. Encoding is performed by the low image quality encoder 125. As shown in FIGS. 2C and 2D, the encoded video signals 510 and 520 are sent with a delay of a time t1 required for the encoding process in the low image quality encoders 115 and 125, respectively.

  The video signals 515 and 525 encoded by the low image quality encoders 115 and 125 are transmitted from the imaging side unit 100 to the monitor side unit 150 via the network 102 (hereinafter, this direction is referred to as “upward direction”). Is done. Since the video signals 515 and 525 sent from the imaging side unit 100 are transmitted via the network 102, they are input to the monitor side unit 150 after being delayed by the transmission delay t2 in the upstream direction of the network 102 (FIG. 2). (See (d)). The video signals 560 (515) and 570 (525) input to the monitor side unit 150 are input to the low image quality decoders 160 and 170.

  The video signals 560 and 570 are decoded by the low image quality decoders 160 and 170, and the decoded video signals 565 and 575 are displayed as low quality images on the monitor units 165 and 175. At that time, the video signals 565 and 575 transmitted from the low image quality decoders 160 and 170 to the monitor units 165 and 175 are transmitted with a delay of the time t3 required for decoding processing in the low image quality decoders 160 and 170 (FIG. 2). (See (e)).

  Now, when the video (video frame A1) from the first imaging unit 110 is displayed on the monitor unit 165 and the video (video frame B1) from the second imaging unit 120 is displayed on the monitor unit 175, the user can It is assumed that a switching operation is performed in order to obtain a high-quality video from the imaging unit 120. It is assumed that the video from the first imaging unit 110 has been selected and displayed as a high-quality video before the switching operation. In this case, the video switching result expected by the user is that the video from the first imaging unit 110 that has been displayed until now ends at the video frame A1, and then the video frame B2 of the second imaging unit 120 is displayed. After that, the video frame of the second imaging unit 120 is continuously displayed. That is, the video frames become A1, B2,..., Bn,.

  The switching command 580 output from the operation unit 180 by the user's switching operation is controlled via the network 102 in the direction from the monitor unit 150 to the imaging unit 100 (hereinafter, this direction is referred to as “downward direction”). Sent to the unit 130. Then, the switching command 580 reaches the control unit 130 after being delayed by a transmission delay t4 in the downstream direction of the network 102 (see FIG. 2F).

  From the above, after the low-quality images captured by the first imaging unit 110 and the second imaging unit 120 are output from the first imaging unit 110 and the second imaging unit 120, the monitor-side unit 150 It can be seen that there is a delay before the output switching command reaches the control unit 130 of the imaging side unit 100. From FIG. 2, the delay time tn is determined from the encoding processing time t1 of the low image quality encoders 115 and 125, the transmission delay t2 in the upstream direction of the network 102, the decoding processing time t3 of the low image quality decoders 160 and 170, and the network 102. It is the total time of transmission delay t4 in the downlink direction. That is, when the user performs an operation of switching the high-quality video while watching the low-quality video, when the switching command reaches the control unit 130, the video frame imaging unit 110 that the video user has performed the switching operation, Delayed from the delivery from 120 by a delay time tn. For this reason, the video frame sent out from the imaging unit 120 is ahead of the frame B1, and even if switching is performed at that timing, switching at the timing desired by the user is not performed.

  Therefore, in the video transmission system according to the present embodiment, the high-quality video is switched from the video frame A1 to the video frame B2 based on the switching command 580 that has arrived after the delay time tn described above, and the high-quality encoder 145. The delay unit 140 is provided in the imaging side unit 100 so as to be input to the imaging side unit 100. As shown in FIG. 2G, the delay time tα in the delay unit 140 includes at least the encoding processing time t1 of the low image quality encoders 115 and 125, the transmission delay t2 in the upstream direction of the network 102, the low image quality decoder 160, It is set to a total time tn of 170 decoding processing time t3 and downstream transmission delay t4 of the network 102. In FIG. 2G, the delay time tα is set to the delay time tn.

  The video signals of the first imaging unit 110 and the second imaging unit 120 input to the delay unit 140 are delayed by a delay time tα and transmitted from the delay unit 140 (see FIG. 2H).

  When the switching unit 143 receives the switching command from the control unit 130, the switching unit 143 switches the video from the next of the video frame A1 to the video frame B2,... Bn based on the switching command (see FIG. 2 (i)).

  As a result, the high-quality video is switched from the video frame A1 to B2 as expected by the user. Hereinafter, as shown in FIGS. 2 (i) to 2 (l), the high-quality video signal 645 sent from the high-quality encoder 145 passes through the transmission delay of the upstream network 102, and the high-quality decoder 190 of the monitor side unit 150. To enter. The high-quality video signal 695 sent from the high-quality decoder 190 passes through the decoding processing time in the high-quality decoder 190, and a high-quality video is obtained by a monitor connected at the subsequent stage.

  As described above, the delay time tα in the delay unit 140 includes the encoding processing time t1 of the low image quality encoders 115 and 125, the transmission delay t2 in the upstream direction of the network 102, and the decoding processing time t3 of the low image quality decoders 160 and 170. As described above, it is the total time of the transmission delay t4 in the downstream direction of the network 102. Among these, the encoding processing time t1 of the low image quality encoders 115 and 125 and the decoding processing time t3 of the low image quality decoders 160 and 170 can be grasped in advance as system design values. However, the transmission delay of the network differs depending on what network the imaging unit 100 and the monitor unit 150 are connected to.

  Therefore, the delay time tα input from the first imaging unit 110 and the second imaging unit 120 in the delay unit 140 of the imaging side unit 100 is changed to the operation unit 180 of the monitor side unit 150 and the setting signal is captured. Means (not shown) for sending out via the network 102 may be included in the control unit of the side unit 100.

  Specifically, the increase / decrease command for the delay time tα is sent to the control unit 130 via the network 102 as in the above-described video switching command. The control unit 130 sends an increase / decrease command signal for the delay time tα to the delay unit 140. The delay unit 140 increases or decreases the delay time tα until the input video is output in accordance with an increase / decrease command signal for the delay time tα.

  By configuring the operation unit 180 in such a configuration, when the low-quality monitor units 165 and 175 monitor the low-quality video while switching to the high-quality video in a certain scene (screen), the user intends The switching timing is adjusted by instructing whether to increase or decrease the delay time tα in the delay unit 140 using the operation unit 180 when the switching timing is shifted. It becomes possible to do. As a result, it is possible to adjust the switching timing according to the transmission delay of the connected network 102, and it is possible to switch high-quality video at the timing expected by the user.

  On the other hand, when the network 102 is a dedicated line, the transmission delay of the network 102 does not change dynamically during use. However, when the network 102 is a public network such as the Internet, since an unspecified number of users use the network, the transmission delay of the network changes every moment. In such a network form, the user frequently adjusts the delay time tα in the delay unit 140 by the operation unit 180, which is not preferable in practice.

  Therefore, a means for measuring the transmission delay may be provided in the control unit 130. Specifically, the control unit 130 periodically transmits a packet to the monitor unit 150 so that the monitor unit 150 returns a response. The control unit 130 measures the time from the packet transmission until the response is received, and dynamically changes the delay time of the delay unit 140 based on the measurement result.

  The time from the packet transmission to the response reception is the total value of the upstream transmission delay and the downstream transmission delay of the network 102, and the upstream network transmission delay t2 shown in FIG. The transmission delay t4 is measured. By adding the encoding processing time t1 of the low image quality encoders 115 and 125 and the decoding processing time t3 of the low image quality decoders 160 and 170 to this measurement result, the optimum delay time tn can be obtained and the transmission delay of the network is dynamically increased. Even if it changes, it can be automatically adjusted to the expected switching timing.

  Note that the monitor side unit 150 of the present embodiment processes video data sent from the imaging side unit 100 by hardware. However, the present invention is not limited to this, and the same function may be realized by software. That is, the above video data processing may be realized by a CPU or the like executing a predetermined program (the same applies to the following embodiments).

Embodiment 2
FIG. 3 is a diagram showing the configuration of the second embodiment of the video transmission system according to the present invention. In the present embodiment, a description will be given of a configuration that can improve the accuracy of video switching timing even via a network by using a time code given to each video frame. In FIG. 3, the same elements as those in the above embodiment are denoted by the same reference numerals and description thereof is omitted.

  In FIG. 3, the first imaging unit 110 and the second imaging unit 120 of the imaging-side unit 100 </ b> A include a unit (not shown) that outputs the captured video signal with the same time code. The time code is assigned a different value for each frame of the video. For example, if the assigned time code is 12: 34: 56: 10, the video frame is the 10th frame at 12:34:56. Can be uniquely identified. The value of the time code given to the video frame is held even if the video frame is subjected to the encoding process of the encoder or the decoding process of the decoder.

  On the other hand, the monitor unit 151 is provided with a time code detection unit 185 that detects the value of the time code from the video frames transmitted from the low image quality decoders 160 and 170. The time code detection unit 185 detects the time code assigned to the video frames transmitted from the low image quality decoders 160 and 170 (the time code assigned to each video frame is the same) for each frame. The detected time code is sent to the operation unit 180 every frame.

  When the operation unit 180 performs the switching operation of the high-quality video, the operation unit 180 sends the time code of the video frame for which the switching operation has been performed to the control unit 130 of the imaging-side unit 100A via the network 102 together with the video switching command. To do.

  In the imaging side unit 100A, the control unit 130 selects the video data from either the first imaging unit 110 or the second imaging unit 120 based on the switching command and the time code value. To control. Specifically, the switching unit 143 detects the time code given to the video signal transmitted from the delay unit 140, and the detected time code and the value of the time code transmitted from the operation unit 180 together with the switching command. When the two match, the control unit 130 controls the switching unit 143 to switch the selected video data.

  As described above, in the present embodiment, a high-quality video is recorded at a timing when the time code given to the video signal sent from the delay unit 140 matches the value of the time code sent from the operation unit 180 together with the switching command. Since the switching unit 143 is controlled so as to switch to, the video switching timing can be performed with accuracy in units of frames.

  Regarding the delay time provided in the delay unit 140, the delay time larger than the fluctuation amount of the transmission delay of the network 102 between the encoding processing time t1 of the low image quality encoders 115 and 125 and the decoding processing time t3 of the low image quality decoders 160 and 170. It is preferable to provide a delay time in consideration of the above. As a result, even when the transmission delay of the network 102 changes dynamically, the user can adjust the video switching timing with accuracy in units of frames without adjusting the delay time tα in the delay unit 140.

Embodiment 3
FIG. 4 is a diagram showing the configuration of the third embodiment of the video transmission system according to the present invention. In the present embodiment, a configuration is described in which video data captured by the first imaging unit 110 and the second imaging unit 120 is encoded by a high-quality encoder, and then each encoded video data is delayed by the delay unit 140. To do. In FIG. 4, the same elements as those in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the first and second embodiments, video data captured by the first imaging unit 110 and the second imaging unit 120 is delayed by a delay unit 140 for a predetermined time, and the first imaging unit 110 or the second imaging unit 143 is delayed in the switching unit 143. The example in which any one of the video data of the imaging unit 120 is selected and the video data from the selected imaging unit 120 is input to the high-quality encoder 145 has been described. However, if the video data before being encoded by the delay unit 140 is to be delayed, a large capacity memory is required for the delay unit 140.

  Therefore, in the present embodiment, as shown in FIG. 4, the video data captured by the first imaging unit 110 and the second imaging unit 120 are sent to the high-quality encoders 145A and 145B, and the high-quality encoders 145A and 145B are transmitted. In this configuration, the video data encoded in step 1 is input to the delay unit 140.

  As in the second embodiment, the first imaging unit 110 and the second imaging unit 120 of the imaging-side unit 100A include means (not shown) that outputs the captured video signal with the same time code. ing. In addition, the time code given to the video frame by the first imaging unit 110 and the second imaging unit 120 is retained even when the video frame undergoes the encoding process of the high image quality encoders 145A and 145B. It has become. Other configurations are the same as those in the second embodiment.

  As described above, in the video transmission system according to the present embodiment, the high-quality encoders 145A and 145B are arranged before the delay unit 140, and the high-quality encoders 145A and 145B are provided for the imaging units 110 and 120, respectively. With this configuration, high-quality video can be switched at a timing intended by the user, and the memory capacity required for the delay unit 140 can be reduced.

Embodiment 4
FIG. 5 is a diagram showing the configuration of the fourth embodiment of the video transmission system according to the present invention. In the present embodiment, the imaging side unit described in Embodiments 1 to 3 includes a plurality of imaging units. However, in the present embodiment, the imaging side unit includes only one imaging unit. Further, the communication between the imaging side unit and the monitor side unit is configured by a wireless network instead of a wired network. By configuring with a wireless network, the portability and mobility of equipment will increase. In FIG. 5, the same elements as those in the above embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In FIG. 5, the first imaging unit 101A includes a first imaging unit 110, a low image quality encoder 115, an interface unit 105A, a control unit 130A, a switch unit 135A, a delay unit 140A, and a high image quality encoder. 145A and antenna portion 106A.

  The first imaging unit 110 outputs a captured video signal with a time code, and sends the video signal with the time code to the low image quality encoder 115 and the high image quality encoder 145A. The low image quality encoder 115 encodes the video signal input from the first imaging unit 110 and sends it to the interface unit 105A.

  The high image quality encoder 145A encodes the video data from the first imaging unit 110 and sends the encoded video data to the delay unit 140A. The delay unit 140A delays the video data from the first imaging unit 110 input from the high image quality encoder 145A for a predetermined time, and sends this to the switch unit 135A.

  The control unit 130A receives a switching command including a time code sent from the operation unit 180 of the monitor-side unit 151 via the network 102. When the switching command indicates the first imaging unit 110, the control unit 130A has high image quality. The switch unit 135A is controlled to turn on the video output command. If the switching command does not indicate the first imaging unit 110, the switch unit 135A is controlled to turn off the high-quality video output command.

  When the switching command indicates the first imaging unit 110, the switch unit 135A is based on the control of the control unit 130A and the time code of the video data input from the delay unit 140A matches the time code specified from the control unit 130A. The switch unit 135A is turned on, and the video input from the delay unit 140A is sent to the interface unit 105A. In addition, when the switching command does not indicate the first imaging unit 110, the switch unit 135A has the time code of the video data input from the delay unit 140A specified by the control unit 130A based on the control of the control unit 130A. When the time code matches, the output switch unit 135A is turned off, and the output of the video data input from the delay unit 140A to the interface unit 105A is stopped.

  The configuration and operation of the second imaging side unit 101B are the same as those of the first imaging side unit 101A. The monitor unit 151 is the same as that in the second and third embodiments.

  The operation of the video transmission system of the present embodiment configured as described above will be described. In the first imaging unit 101A, the video data (with time code) captured by the first imaging unit 110 is encoded by the low image quality encoder 115 and transmitted from the antenna unit 106A via the interface unit 105A. The The video data is received by the network interface unit 155 of the monitor unit 151 via the network 102, decoded by the low image quality decoder unit 160, and displayed on the monitor unit 165.

  Similarly, in the second imaging side unit 101B, the video data (with time code) captured by the second imaging unit 120 is encoded by the low image quality encoder 125, and the antenna unit 106B via the interface unit 105B. Sent from The video data is received by the network interface unit 155 of the monitor side unit 151 via the network 102, decoded by the low image quality decoder unit 170, and displayed on the monitor unit 175.

  The time code detector 185 detects the time code from the video frame output from the low image quality decoder 160. The detection of the time code by the time code detection unit 185 is executed every frame, and the detected time code is sent to the operation unit 780 every frame.

  In the first imaging unit 101A, the video data (with time code) captured by the first imaging unit 110 is encoded by the high image quality encoder unit 145A and predetermined by the delay unit 140A. After being delayed by the delay time, it is sent to the switch unit 135A.

  Similarly, in the second imaging side unit 101B, the video data captured by the second imaging unit 120 (added with a time code) is encoded by the high image quality encoder unit 145B and predetermined by the delay unit 140B. After being delayed by the delay time, the data is sent to the switch unit 135B.

  When the user performs a switching operation for switching a high-quality video to a video from the first imaging unit 110 of the first imaging-side unit 101A, the operation unit 180 displays the time code when the switching operation is performed as a video. The network interface unit 155 transmits, for example, broadcast methods such as broadcast and multicast. The switching command including the time code is simultaneously transmitted to the first imaging side unit 101A and the second imaging side unit 101B via the network 102.

  In the first imaging unit 101A, the switch unit 135A is controlled by the control unit 130A, and is turned on when the time code of the video data input from the delay unit 140A matches the time code specified from the control unit 130A. The high-quality video input from the delay unit 140A is sent to the interface unit 105A.

  In contrast, in the second imaging side unit 101B, the switch unit 135B is controlled by the control unit 130B, and the time code of the video data input from the delay unit 140B matches the time code specified by the control unit 130B. At this time, it is turned off, and the output of the video data input from the delay unit 140B to the interface unit 105B is stopped.

  Further, when the user performs a switching operation for switching the high-quality video to the video from the second imaging unit 120 of the second imaging side unit 101B, the output switch unit in the second imaging side unit 101A 135A is turned off when the time code of the video data input from the delay unit 140A matches the time code specified by the control unit 130A, and outputs the video data input from the delay unit 140A to the interface unit 105A. Stop.

  On the other hand, in the second imaging side unit 101B, the switch unit 135B is turned on when the time code of the video data input from the delay unit 140B matches the time code specified from the control unit 130B, and the delay unit The high-quality video input from 140B is sent to the interface unit 105A.

  As a result, the video sent to the monitor unit via the network 102 as a high-quality video is changed from the video of the first imaging unit 110 to the video of the second imaging unit 120, or the video of the second imaging unit 120. To the video of the first imaging unit 110. Even with the configuration of the present embodiment, it is possible to switch to high-quality video at the timing intended by the user. Further, the accuracy of video switching can be matched in units of frames by using time codes.

  In the present embodiment, the same time code is assigned to the video data by the first imaging unit 110 and the second imaging unit 120, so the time by the time code detection unit 185 in the monitor unit 151 is the same. The code detection is detected on the output side of the low image quality decoder 160. However, the present invention is not limited to this, and a separate time code is assigned to each video data from the first imaging unit 110 and the second imaging unit 120, and these are detected. May be detected from the output side of the low image quality decoders 160 and 170.

  In the present embodiment, an example in which two imaging side units of the first imaging side unit 101A and the second imaging side unit 101B are arranged has been described. However, the present invention is not limited thereto, and, for example, three or more. The imaging side unit may be arranged.

  In the present embodiment, in the first imaging side unit 101A and the second imaging side unit 101B, the high image quality encoders 145A and 145B encode the video data from the imaging units 110 and 120 and perform the encoding process. Although an example in which video data is sent to the delay units 140A and 140B has been described, the present invention is not limited to this, and the video data may be executed as in the first embodiment. Moreover, although the example which detects the time code in the monitor side unit 151 and sends this to the operation part 180 was demonstrated, this can also be performed like Embodiment 1. FIG.

  The embodiments disclosed herein are illustrative and not limiting. The present invention is defined by the terms of the claims, rather than the scope described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The video transmission system of the present invention is useful for an application (for example, a video transmission system from a recording site to a broadcasting station) that switches high-quality video while monitoring low-quality video from a plurality of cameras at a remote location.

1 is a configuration diagram illustrating a first embodiment of a video transmission system according to the present invention. FIG. It is a timing chart which shows the operation example of the video transmission system of 1st Embodiment. It is the block diagram which showed 2nd Embodiment of the video transmission system which concerns on this invention. It is the block diagram which showed 3rd Embodiment of the video transmission system which concerns on this invention. It is the block diagram which showed 4th Embodiment of the video transmission system which concerns on this invention.

  100 imaging side unit, 102 network, 105, 155 network interface unit, 110 first imaging unit, 115, 125 low image quality encoder, 120 second imaging unit, 130 control unit, 140 delay unit, 143 switching unit, 145 high Image quality encoder, 150 Monitor unit, 160, 170 Low image quality decoder, 165, 175 Monitor unit, 180 operation unit, 185 Time code detection unit, 190 High image quality decoder

Claims (12)

A video transmission system comprising an imaging device capable of transmitting captured video data, and a monitor device capable of receiving video data generated by the imaging device via a network,
a) The imaging device comprises:
Interface means for communicating with the monitor device via the network;
A plurality of imaging means;
A first encoding unit that is provided for each imaging unit and encodes video data captured by the imaging unit at a low bit rate;
Delay means for delaying each video data imaged by each imaging means for a predetermined time;
Switching means for inputting a plurality of video data from the delay means, selecting one of the inputted plurality of video data, and outputting;
Second encoding means for encoding the video data output by the switching means at a high bit rate;
Control means for controlling the operation of the switching means,
The video data encoded by the first and second encoding means is transmitted to the monitor device via the interface means,
b) The monitor device
Interface means for communicating with the imaging device via the network;
First decoding means for decoding a plurality of video data encoded by the first encoding means, received from the imaging device via the interface means;
A plurality of display means for displaying each of the video data decoded by the first decoding means;
Second decoding means for decoding video data encoded by the second encoding means, received from the imaging device via the interface means;
A switching signal indicating an imaging means for receiving an operation instruction for selecting one video from the videos displayed on the plurality of display means by the user and generating video data of the selected video is sent to the interface means. Operating means for transmitting to the imaging device via,
c) The control unit of the imaging device selects video data from one imaging unit indicated by the switching signal from a plurality of video data input from the delay unit based on the switching signal received from the monitor device. And controlling the operation of the switching means to output
A video transmission system characterized by that. A video transmission system comprising an imaging device capable of transmitting captured video data, and a monitor device capable of receiving video data generated by the imaging device via a network,
a) The imaging device comprises:
Interface means for communicating with the monitor device via the network;
A plurality of imaging means for generating video data to which a time code is assigned for each video frame;
A first encoding unit that is provided for each imaging unit and encodes video data captured by the imaging unit at a low bit rate;
Delay means for delaying each video data imaged by each imaging means for a predetermined time;
When a time code is input together with a switching signal via the network, and a video frame provided with a time code that matches the input time code is input from the delay means, the video data indicated by the switching signal Switching means for switching; and
Second encoding means for encoding the video data output by the switching means at a high bit rate;
Control means for controlling the operation of the switching means,
The video data encoded by the first and second encoding means is transmitted to the monitor device via the interface means,
b) The monitor device
Interface means for communicating with the imaging device via the network;
First decoding means for decoding a plurality of video data received through the network and generated by a plurality of imaging means and encoded at a low bit rate;
A plurality of display means for displaying each of the video data decoded by the first decoding means;
Time code detecting means for detecting a time code attached to the video data output from the first decoding means;
Second decoding means for decoding the video data generated by one of the plurality of imaging means and encoded at a high bit rate, received via the network;
The time code information is received from the time code detection means, and the time code of the video data when one video data is selected by the user, together with the switching signal indicating the imaging means for generating the video data of the selected video. Operation means for transmitting to the imaging device via the network,
c) The switching means of the imaging device inputs a time code together with a switching signal via the network, and when the video frame to which a time code that matches the input time code is input is input, the switching signal is Switch to the specified video data,
A video transmission system characterized by that. A video transmission system comprising an imaging device capable of transmitting captured video data, and a monitor device capable of receiving video data generated by the imaging device via a network,
a) The imaging device comprises:
Interface means for communicating with the monitor device via the network;
A plurality of imaging means for generating video data to which a time code is assigned for each video frame;
A first encoding unit that is provided for each imaging unit and encodes video data captured by the imaging unit at a low bit rate;
A second encoding unit provided for each of the imaging units and encoding video data captured by the imaging unit at a high bit rate;
Delay means for delaying each of the video data encoded by the second encoding means for a predetermined time;
Switching means for inputting a plurality of video data from the delay means, selecting one of the inputted plurality of video data, and outputting;
Control means for controlling the operation of the switching means,
The video data encoded by the first encoding means and the video data output from the switching means are transmitted to the monitor device via the interface means,
b) The monitor device
Interface means for communicating with the imaging device via the network;
First decoding means for decoding a plurality of video data generated by a plurality of imaging means and encoded at a low bit rate, received via the network;
A plurality of display means for displaying each of the video data decoded by the first decoding means;
Second decoding means for decoding video data generated by one of the plurality of imaging means and encoded at a high bit rate, received via the network;
Time code detecting means for detecting a time code attached to the video data output from the first decoding means;
The time code information is received from the time code detection means, and the time code of the video data when one video data is selected by the user, together with the switching signal indicating the imaging means for generating the video data of the selected video. Operation means for transmitting to the imaging device via the network,
c) The switching means of the imaging device inputs a time code together with a switching signal via the network, and when the video frame to which a time code that matches the input time code is input is input, the switching signal is Switch to the specified video data,
A video transmission system characterized by that. A video transmission system comprising an imaging device capable of transmitting captured video data, and a monitor device capable of receiving video data generated by the imaging device via a network,
a) The imaging device comprises:
Interface means for communicating with the monitor device via the network;
Imaging means for generating video data to which a time code is assigned for each video frame;
First encoding means for encoding video data imaged by the imaging means at a low bit rate;
Second encoding means for encoding video data imaged by the imaging means at a high bit rate;
Delay means for delaying the video data encoded by the second encoding means for a predetermined time;
Switch means for sending the video data sent from the delay means to the interface means when turned on, and to stop sending the video data sent from the delay means to the interface means when turned off;
Control means for controlling the operation of the switch means based on a switching signal received from the monitor device via the interface means, and a control means for inputting a time code together with the switching signal from the monitor device via the network,
The video data encoded by the first encoding means and the video data output from the switch means are transmitted to the monitor device via the interface means,
b) The monitor device
Interface means for communicating with the imaging device via the network;
First decoding means for decoding a plurality of video data generated by a plurality of imaging means and encoded at a low bit rate, received via the network;
A plurality of display means for displaying each of the video data decoded by the first decoding means;
Time code detecting means for detecting a time code attached to the video data output from the first decoding means;
Second decoding means for decoding the video data generated by one of the plurality of imaging means and encoded at a high bit rate, received via the network;
A switching signal indicating the time code of the video data when one video data is selected by the user, receiving the time code information from the time code detection means, and indicating the imaging means for generating the video data of the selected video And an operation means for transmitting to the imaging device via the network,
c) Based on the control of the control unit, the switch unit of the imaging device specifies the imaging device when the video signal to which the time code that matches the input time code is input is input. Turn on when the switch signal does not specify the imaging device,
A video transmission system characterized by that. The delay time in the delay means is
The time required for the encoding process in the first encoder means of the imaging device;
The time required for the decoding process in the first decoding means of the monitor device;
Network transmission delay time required to send video data from the imaging device to the monitor device;
It is set to be equal to or greater than the total time of the network transmission delay time required to send video data from the monitor device to the imaging device.
The video transmission system according to claim 1, wherein the video transmission system is a video transmission system. An imaging device capable of transmitting video data captured via a network to a monitor device,
Interface means for communicating with the monitor device via the network;
A plurality of imaging means;
A first encoding unit that is provided for each imaging unit and encodes video data captured by the imaging unit at a low bit rate;
Delay means for delaying each video data imaged by each imaging means for a predetermined time;
Switching means for inputting a plurality of video data from the delay means, selecting one of the inputted plurality of video data, and outputting;
Second encoding means for encoding the video data output by the switching means at a high bit rate;
Control means for controlling the operation of the switching means,
Video data encoded by the first and second encoding means is transmitted to the monitor device via the interface means,
The control means receives a switching signal from the monitor device, and selects video data from one imaging means indicated by the switching signal from a plurality of video data input from the delay means based on the switching signal. And controlling the operation of the switching means to output
An imaging apparatus characterized by that. An imaging device capable of transmitting video data captured via a network to a monitor device,
Interface means for communicating with the monitor device via the network;
A plurality of imaging means;
A first encoding unit that is provided for each imaging unit and encodes video data captured by the imaging unit at a low bit rate;
A second encoding unit provided for each of the imaging units and encoding video data captured by the imaging unit at a high bit rate;
Delay means for delaying each of the video data encoded by the second encoding means for a predetermined time;
Switching means for inputting a plurality of video data from the delay means, selecting one of the inputted plurality of video data, and outputting;
Control means for controlling the operation of the switching means,
The video data encoded by the first encoding means and the video data output from the switching means are transmitted to the monitor device via the interface means,
The control means receives a switching signal from the monitor device, and selects video data from one imaging means indicated by the switching signal from a plurality of video data input from the delay means based on the switching signal. And controlling the operation of the switching means to output
An imaging apparatus characterized by that. The imaging means gives a time code for each video frame of the captured video data,
The switching means inputs a time code together with a switching signal via the network, and when the video frame to which the time code that matches the input time code is input is input to the video data indicated by the switching signal The imaging apparatus according to claim 6, wherein switching is performed. An imaging device capable of transmitting video data captured via a network to a monitor device,
Interface means for communicating with the monitor device via the network;
Imaging means for generating video data to which a time code is assigned for each video frame;
First encoding means for encoding video data imaged by the imaging means at a low bit rate;
Second encoding means for encoding video data imaged by the imaging means at a high bit rate;
Delay means for delaying the video data encoded by the second encoding means for a predetermined time;
Switch means for sending the video data sent from the delay means to the interface means when turned on, and to stop sending the video data sent from the delay means to the interface means when turned off;
Control means for controlling the operation of the switch means based on a switching signal received from the monitor device via the interface means,
The control means inputs a time code together with a switching signal from the monitor device via the network,
The switch means is turned on when the switching signal designates the imaging device when a video frame provided with a time code that matches the input time code is input based on the control of the control means, An image pickup apparatus that is turned off when the switching signal does not designate the image pickup apparatus. The delay time in the delay means is
The time required for the encoding process in the first encoder means of the imaging device;
The time required for the decoding process in the first decoding means of the monitor device;
Network transmission delay time required to send video data from the imaging device to the monitor device;
It is set to be equal to or greater than the total time of the network transmission delay time required to send video data from the monitor device to the imaging device.
The imaging apparatus according to any one of claims 6 to 9, wherein A monitor device capable of receiving video data generated by a plurality of image pickup means from at least one image pickup apparatus including at least one image pickup means via a network,
First decoding means for decoding a plurality of video data generated by a plurality of imaging means and encoded at a low bit rate, received via the network;
A plurality of display means for displaying each of the video data decoded by the first decoding means;
Second decoding means for decoding video data generated by one of the plurality of imaging means and encoded at a high bit rate, received via the network;
A switching signal indicating an imaging unit that receives an operation instruction for selecting one video from the videos displayed on the plurality of display units and generates video data of the selected video is transmitted via the network. And an operating means for transmitting to the imaging device. A time code detecting means for detecting a time code attached to the video data output from the first decoding means;
The operation means receives time code information from the time code detection means, and sends out the time code of the video data when one video data is selected by the user together with the switching signal. Item 12. The monitoring device according to Item 11.

Images