JP4616211B2 - Video distribution support system - Google Patents

Description

  The present invention relates to a video distribution support system for always ensuring good video quality when video captured by a network camera is distributed to a receiving terminal via a communication network.

  In recent years, a network camera has been installed at a construction site or a disaster occurrence site, and the video captured by this network camera is distributed to a remote receiving terminal via a communication network such as the Internet or LAN. The technology that has been installed in the technical management department to facilitate on-site supervision and situational understanding is being adopted.

  In this case, the type of network camera is a type in which the camera operator manually operates pan, tilt, and zoom (hereinafter referred to as a portable type), and the camera body is fixed to a tripod or a case. Then, there is a type that performs pan, tilt, and zoom operations (hereinafter referred to as a fixed type) by giving a control signal for camera driving operation from the outside.

  By the way, when video captured by such a portable or fixed network camera is distributed to a receiving terminal via a communication network, the image quality depends on the camera operation speed, transmission server performance, and network traffic status. It is greatly influenced by factors such as the processing capability of the receiving terminal.

  Conventionally, in a transmission-side Web server, traffic of a communication network is measured, and a frame rate of a video transmitted from a network camera is controlled according to the traffic situation (for example, see Patent Document 1), or a communication network A technique has been proposed in which the compression rate of video transmitted from a network camera is controlled in accordance with the traffic conditions (see, for example, Patent Documents 2 and 3), and image quality is maintained appropriately.

  As another conventional technology, video signals captured by a fixed network camera are distributed to the receiving terminal via a line communication network such as a telephone line, and the pan, tilt, and zoom operations of the fixed network camera are performed. A technique has also been proposed in which a video signal and a control signal can be efficiently transmitted by transmitting a control signal for controlling the video signal via a packet communication network (see, for example, Patent Document 4).

JP 2003-163914 A JP 7-288806 A JP 2001-36655 A JP 2003-299069 A

  By the way, in order to more accurately perform on-site supervision and grasp of the situation at a construction site or a disaster occurrence site, it is often required to photograph the state of the site from various directions. As described above, in order to properly capture the situation in the field, various camera operations such as panning, tilting, and zooming are necessary. When such camera operations are performed, the operation speed greatly affects the video quality. . For example, when the frame rate during video transmission is low and the camera operation speed is fast, the image quality is greatly degraded. This applies not only to the portable type but also to the fixed type. Especially when the frame rate is low during video transmission, if the pan / tilt / zoom operation is too fast, the image quality is greatly degraded. As a result, there is a problem that the photographing object cannot be sufficiently confirmed and the photographing efficiency is lowered.

  In the prior art described in Patent Documents 1 to 3 above, the video frame rate is controlled or the video compression rate is controlled according to the traffic situation of the communication network. Even when such measures are taken on the transmission server side, if the camera operation speed is not appropriate, the video quality (frame rate and image quality) is good regardless of whether it is portable or fixed. It is inevitable that it will deteriorate greatly.

  In other words, in the past, it was possible to control the video frame rate or the video compression rate according to the traffic situation of the communication network, but in the case of a portable network camera in particular, the camera operation The person cannot immediately recognize the image quality of the video displayed on the receiving terminal side. In other words, it is difficult to determine whether or not the camera operation speed is properly maintained at the time of shooting, and if the operation speed is inappropriate, the video quality at the receiving terminal deteriorates, and on-site supervision and situations There was a problem that it was impossible to grasp enough.

  In the case of the prior art described in Patent Document 4, since the video signal transmitted from the fixed network camera is displayed on the monitor screen of the receiving terminal, the camera operator can monitor the monitor screen of the receiving terminal. If the image quality of the video signal is judged to be good by observing the image, and it is determined that the image quality has deteriorated, the control signal is transmitted from the receiving terminal side to the network camera, and the speed of pan, tilt and zoom operations becomes appropriate It is possible to control as follows.

  However, in the case of this prior art, the camera operator controls the camera operation speed by judging the visual appearance of the image displayed on the monitor screen of the receiving terminal installed far away from the fixed network camera. However, it is difficult to always operate the camera at an appropriate speed according to the degree of deterioration of the frame rate. In other words, the camera operator only looks at the video on the monitor screen to determine an appropriate camera operation speed and outputs a drive control signal, so to speak, it relies on the experience and intuition of the camera operator, It does not automatically control an appropriate operation speed based on the degree of deterioration, and for this reason, it is difficult to always obtain an appropriate video quality. Furthermore, on a general remote operation screen, the camera operation speed for performing pan / tilt / zoom is often set to a fixed value in advance, and the camera operation speed cannot be changed in real time.

  The present invention has been made in order to solve the above-described problem, and is capable of observing video having appropriate video quality on the receiving terminal side regardless of whether the network camera is portable or fixed. An object is to provide a distribution support system.

In order to achieve the above object, the present invention adopts the following configuration.
That is, the video distribution support system of the present invention includes a network camera that captures a video and transmits it to a communication network, and a receiving terminal that receives a video signal distributed from the network camera via the communication network. The receiving terminal includes a frame rate detection unit that detects a frame rate of the received video, a camera operation speed instruction unit that instructs an appropriate camera operation speed of the network camera corresponding to the frame rate detected by the frame rate detection unit, And a camera operation speed notifying means for notifying the network camera or the operator of the camera operation speed instructed by the camera operation speed instructing means, and the frame rate detecting means is the receiving terminal. Displayed on the monitor screen of It detects the change in illuminance of the time code included in the video from the network camera, and detects the frame rate from the change in illuminance. The camera operation speed instruction means controls the frame rate and appropriate operation of the network camera. A correspondence table in which speeds are associated in advance, and the operation speed of the network camera corresponding to the frame rate detected by the frame rate detection means is determined with reference to the correspondence table. Yes.

According to the present invention, the frame rate detection means detects the frame rate from the illuminance change of the time code included in the video from the network camera displayed on the monitor screen of the receiving terminal, and based on this, the camera operation speed instruction means A series of feedback systems is constructed in which the operation speed of the network camera corresponding to the frame rate is determined with reference to the correspondence table, and the camera operation speed notification means notifies the network camera side of the information on the camera operation speed . Therefore, when the video frame rate is lowered due to the influence of the traffic of the communication network and the video display performance of the receiving terminal on the receiving side, an appropriate camera operation speed can be instructed according to the frame rate. As a result, regardless of whether the network camera is a portable type or a fixed type, it is possible to always observe an image having an appropriate quality on the receiving terminal side.

Embodiment 1 FIG.
FIG. 1 is an overall configuration diagram of a video distribution support system according to Embodiment 1 of the present invention.

  The video distribution support system 1 according to the first embodiment includes a network camera 2 and a receiving terminal 4 that receives a video signal distributed from the network camera 2 via the Internet 3. In this example, the network camera 2 and the receiving terminal 4 are connected via the Internet 3. However, the present invention is not limited to this, and other communication networks such as LAN and WAN can be used.

  The above-described network camera 2 is a portable type that is carried by the camera operator M1 and manually performs pan / tilt / zoom operations, and includes a photographing unit 21 having a solid-state image sensor (CCD) for photographing a video, 21 includes a liquid crystal monitor 22 that displays the video obtained at 21 and a Web server function unit 23 that compresses the video obtained at the photographing unit 21 and distributes the video to the Internet 3.

  On the other hand, the receiving terminal 4 includes, for example, a personal computer or a workstation. The receiving terminal 4 includes a liquid crystal monitor 41, a frame rate detector 5, a camera operation speed indicator 6, and a camera operation speed. Notification means 7 is provided.

  As shown in FIGS. 2 to 4, the frame rate detector 5 includes a sensor unit 51 and a main body unit 52, both of which are connected by a cable 53. The sensor unit 51 detects a change in illuminance of the time code TC with second accuracy included in the video signal from the network camera 2 displayed on the liquid crystal monitor 41 of the receiving terminal 4. For example, the sensor unit 51 is a CCD or a photodiode. A light receiving element 51a and a condensing lens 51b are housed in a case 51c, and the sensor unit 51 faces a display position of a time code TC in a window displayed on the liquid crystal monitor 41 of the receiving terminal 4. Thus, it is detachably attached to the frame of the liquid crystal monitor 41 via the attachment 13. The main body 52 detects the frame rate from the illuminance change of the time code TC detected by the sensor 51, and adjusts the sensitivity reference value Bb of the output level of the detection signal from the sensor 51. 52a and the like.

  As shown in FIG. 8, the camera operation speed indicator 6 has a correspondence table TB1 in which a frame rate is associated with an appropriate operation speed of the network camera 2 in advance, and frame rate detection is performed with reference to this correspondence table TB1. An appropriate operation speed of the network camera 2 corresponding to the frame rate detected by the device 5 is determined, and this is output as a camera operation speed command signal.

  The camera operation speed notifying means 7 includes a voice synthesizer 71 and a telephone 72 that sends out a voice signal synthesized by the voice synthesizer 71 to a telephone line network 8 as a circuit switching network. Note that the telephone line network 8 may be either one or both of a fixed telephone network and a mobile telephone network. Then, as shown in FIG. 9, the speech synthesizer 71 has a correspondence table TB2 in which camera operation speed command signals are associated with audible sounds having various sound patterns, and the camera is referenced with reference to this correspondence table TB2. The camera operation speed command signal given from the operation speed indicator 6 is converted into an audible sound corresponding to the signal, and the audible sound is synthesized with the voice of the caller M2 on the receiving terminal 4 side talking with the camera operator M1. It has become.

  Next, the operation of the video distribution support system according to the first embodiment will be described with reference to FIGS.

  The video imaged by the imaging unit 21 of the portable network camera 2 is distributed to the receiving terminal 4 through the Internet 3 by the Web server function unit 23. At that time, the Web server function unit 23 adds the time code TC to the video signal and transmits it to the receiving terminal 4 so that the photographing time can be known. In addition, an image obtained by the photographing unit 21 is also displayed on the liquid crystal monitor 22.

  On the receiving terminal 4 side, the video distributed from the network camera 2 is displayed on the liquid crystal monitor 41. At this time, the sensor unit 51 of the frame rate detector 5 receives the receiving terminal 4 as shown in FIG. The average illuminance change of the time code TC with second accuracy included in the video signal from the network camera 2 displayed on the screen of the liquid crystal monitor 41 (specifically, the brightness of characters displayed in seconds of the time code TC) Change) and outputs this as an illuminance change signal.

  In this case, the time change of the illuminance change signal output from the sensor unit 51 is, for example, as shown in FIG. That is, when the frame rate is lower than the unit time (1 second in this example) T0, frames are dropped and the video of the time code TC does not change, so that the detection level change times T1, T2, T3 of the illuminance change signal ,... Become longer than the unit time T0.

  The main body 52 of the frame rate detector 5 regards the level change of the illuminance change signal detected by the sensor unit 51 as a change in the frame of the video and calculates the frame rate from the illuminance change signal (step 1 in FIG. 7). Then, this frame rate detection signal is sent to the camera operation speed indicator 6 at the next stage.

  As described above, in the first embodiment, because the method detects the illuminance change of the time code TC with second accuracy included in the video signal from the network camera 2 displayed on the liquid crystal monitor 41 of the receiving terminal 4, As long as the video has a display of the time code TC in seconds, the frame rate of the actual video displayed on the receiving terminal 4 should be reliably measured regardless of the receiving terminal 4 having any video display capability. Can do. Further, the frame rate is not determined by measuring the traffic of the Internet 3 but is a method of detecting the final frame rate including the influence of the server performance of the network camera 2 and the performance of the receiving terminal 4. Therefore, a more realistic and accurate frame rate can be detected, and it can be realized at a low cost.

  The camera operation speed indicator 6 refers to the correspondence table TB1 shown in FIG. 8, determines an appropriate operation speed of the network camera 2 corresponding to the detected frame rate, and outputs this as a camera operation speed command signal. (Step 2 in FIG. 7). In the example of the correspondence table TB1 shown in FIG. 8, four stages of camera operation speed command signals (signal 1 to signal 4) are output according to the detected frame rate.

  Since the camera operation speed command signal output from the camera operation speed indicator 6 in this way is supplied to the next-stage speech synthesizer 71, the speech synthesizer 71 refers to the correspondence table TB2 shown in FIG. The camera operation speed command signal is converted into an audible sound having a characteristic sound pattern such as a continuous sound, an intermittent sound, and an alarm sound corresponding to the camera operation speed command signal. Then, the audible sound is synthesized with the voice of the caller M2 on the receiving terminal 4 side that makes a call with the camera operator M1.

  In the first embodiment, as shown in the correspondence table TB2 of FIG. 9, the sound pattern of the audible sound generated in response to the camera operation speed command signal from the speech synthesizer 71 takes the following points into consideration. Is set. In other words, if the frame rate is 1 fps or higher, it is not necessary to consider the camera operation speed so much, so that it is generated as a continuous sound of a certain pitch. Conversely, if the frame rate is 0.2 fps or less, the video is not updated for more than 5 seconds, and it is necessary to keep the network camera 2 facing the same subject, so use a tripod or the like. An alarm sound for prompting is generated. Further, in the range of 0.5 fps to 0.2 fps in which the image changes in about 1 second to 5 seconds, the camera operator M1 can prevent the image quality deterioration by adjusting the camera operation speed. In order to make it easy to grasp 3 seconds and 6 seconds during shooting, a 3-beat intermittent sound whose pitch changes every second in the frame rate range of 1 fps to 0.5 fps, When the frame rate is in the range of 0.5 fps to 0.2 fps, an intermittent sound with a period of 3 seconds is generated. Note that the sound pattern of the audible sound is merely an example, and is not limited to this.

  Further, if the sound synthesizer 71 is provided with a volume for adjusting sound when the camera operation speed command signal is converted into an audible sound, the conversation between the camera operator M1 and the caller M2 on the receiving terminal 4 side is hindered. This is convenient because the audible sound can be surely heard by the camera operator M1.

  The voice output synthesized by the voice synthesizer 71 is sent from the telephone 72 installed on the receiving terminal 4 side to the telephone 9 carried by the camera operator M1 via the telephone line network 8. Thereby, when operating the network camera 2, the camera operator M1 can always maintain an appropriate camera operation speed by listening to the telephone 9 for the audible sound transmitted from the receiving terminal 4 side.

  As in the first embodiment, if an audible sound instructing the camera operation speed is transmitted using the telephone network 8, a camera operation speed command signal is returned to the network camera 2 using the Internet 3. Since the feedback delay is smaller and the delay amount is stable, the camera operation speed can always be instructed in real time.

  As described above, in the first embodiment, when the camera operator M1 performs on-site shooting by various camera operations such as pan, tilt, zoom, and focus, the audible sound sent from the receiving terminal 4 side is transmitted. It is possible to always maintain an appropriate camera operation speed while listening with the mobile phone 9. For this reason, it is no longer possible to deliver the flowed video or the video that changes so fast that the viewer is drunk to the receiving terminal 4 side, and the frame rate adapted to the traffic of the Internet 3 and the video display capability of the receiving terminal 4 Since the video can be transmitted, it is possible to always observe a high-quality on-site video at the receiving terminal 4 without causing a problem such as a frame dropping.

With respect to the first embodiment, the following modifications and application examples can be considered.
(1) In the first embodiment, the frame rate detector 5 calculates the frame rate based on the illuminance change of the time code TC included in the video of the network camera 2 displayed on the liquid crystal monitor 41 screen of the receiving terminal 4. However, the present invention is not limited to this, and within the receiving terminal 4, by detecting a frame pulse included in the video signal transmitted from the network camera 2, and counting the pulse interval of the frame pulse, A configuration for detecting the frame rate is also possible. With this configuration, the frame rate can be reliably detected by electrical signal processing in the receiving terminal 4 although the cost is somewhat higher than in the case of the first embodiment. The configuration is simplified.

(2) In the above-described first embodiment, as the camera operation speed notification means 7, the telephone 72 is provided with the voice synthesizer 71 to superimpose the audible sound for instructing the camera operation speed on the call signal. The invention is not limited to this. For example, a synthesized speech utterer that automatically generates a synthesized speech signal corresponding to the camera operation speed calculated by the camera operation speed indicator 6 is provided. By transmitting to the telephone 9 carried by the camera operator M1 through the telephone line network 8, it is possible to make the camera operator M1 recognize an appropriate camera speed. With this configuration, it is possible to automatically instruct the camera operator M1 to an appropriate camera operation speed even if the caller M2 who performs technical guidance or the like does not reside on the installation side of the receiving terminal 4. Therefore, the burden on the administrator side is reduced.

(3) In the first embodiment described above, the camera operation speed notification means 7 instructs the telephone 9 carried by the camera operator M1 through the telephone network 8 to specify an appropriate camera operation speed. Instead, a camera operation speed command signal based on the camera operation speed calculated by the camera operation speed indicator 7 is transmitted directly to the network camera 2 via the Internet 3, and the camera from the receiving terminal 4 is transmitted on the network camera 2 side. The operation speed command signal can be displayed on the liquid crystal monitor 22 as an image. This is convenient because the camera operator M1 does not have to carry the telephone 9 in addition to the network camera 2.

(4) Also, instead of instructing the camera operator M1 with the camera operation speed by voice, the blinking pattern of the LED provided on the network camera 2 is changed according to the type of the camera operation speed command signal, or the vibration pattern of the vibrator It is also possible to notify the camera operator M1 of an appropriate camera operation speed by changing the value according to the type of the camera operation speed command signal.

(5) Further, instead of instructing the camera operator M1 with the camera operation speed by voice, a camera operation speed command signal is transmitted to the network camera 2 via the Internet 3, and from the receiving terminal 4 on the network camera 2 side. It is also possible to control the frame rate of the video signal transmitted to the receiving terminal 4 based on the camera operation speed command signal. According to this configuration, the camera operator M1 is always sent to the receiving terminal 4 side automatically with an image having an appropriate frame rate without being particularly aware of the operation speed of the network camera 2. Increase.

Embodiment 2. FIG.
FIG. 10 is an overall configuration diagram of the video distribution support system according to the second embodiment of the present invention. Components that correspond to or correspond to those of the first embodiment shown in FIG.

  The network camera 2 in the first embodiment is a portable type that is carried by the camera operator M1 and manually performs the pan / tilt / zoom operation. However, the network camera 2 in the second embodiment has a camera body. It is a fixed type that is used in a state where it is fixed to a tripod or a case. For this reason, the fixed network camera 2 includes a photographing unit 21 equipped with a solid-state image pickup device (CCD) for photographing a video, compresses a video obtained by the photographing unit 21 and distributes the video to the Internet 3 or receives a receiving terminal. A web server function unit 23 that receives and processes signals sent from the 4 side, and a drive operation unit 24 that performs pan, tilt, and zoom operations based on camera drive operation commands sent from the receiving terminal 4 side. I have.

  On the other hand, as shown in FIG. 11, the camera operation speed indicator 6 has a correspondence table TB3 in which a frame rate and an appropriate operation speed of the network camera 2 are associated in advance. An appropriate operation speed of the network camera 2 corresponding to the frame rate detected by the rate detector 5 is determined, and this is output as a camera operation speed command signal. Note that the correspondence table TB3 shown in FIG. 11 is also created based on the same idea as the correspondence table TB1 (FIG. 8) in the first embodiment in order to maintain an appropriate camera operation speed.

The camera operation speed notification means 7 includes a telephone 72 and a camera drive operation command generator 73. The camera drive operation command generator 73 generates camera drive operation commands for the pan, tilt and zoom drive operations of the network camera 2 based on the camera operation command signal input by the camera operator M3. A camera operation speed command signal given from the camera operation speed indicator 6 is added to the drive operation command. The telephone 72 transmits a camera drive operation command to which the camera operation speed command signal output from the camera drive operation command generator 73 is added to the network camera 2 from the telephone line network 8 as a circuit switching network. It is.
Since the other configuration is the same as that of the first embodiment shown in FIG. 1, detailed description is omitted here.

  Next, the operation of the video distribution support system 1 according to the second embodiment will be described with reference to FIGS.

  The operation until the frame rate of the video transmitted from the fixed network camera 2 via the Internet 3 is detected by the frame rate detector 5 and the frame rate detection signal is given to the camera operation speed indicator 6 is as follows. This is the same as in the first embodiment.

  The camera operation speed indicator 6 determines an appropriate operation speed of the network camera 2 corresponding to the detected frame rate with reference to the correspondence table TB3 shown in FIG. 11, and outputs this as a camera operation speed command signal. . In the example of the correspondence table TB3 shown in FIG. 11, four stages of camera operation speed command signals (signal 1 to signal 4) are output according to the detected frame rate.

  The camera operation speed command signal output from the camera operation speed indicator 6 in this way is provided to the camera drive operation command generator 73 at the next stage. The camera drive operation command generator 73 generates camera drive operation commands for the pan, tilt, and zoom drive operations of the network camera 2 based on the camera operation command signal input to the receiving terminal 4 by the camera operator M3. . At this time, the camera operation speed command signal instructed by the camera operation speed indicator 6 is added to the camera drive operation command in response to the pan, tilt and zoom operations instructed by the camera drive operation command. That is, as shown in FIG. 12A, a camera operation speed command signal (indicated by an asterisk in the figure) suitable for each operation is provided immediately before the camera drive operation command for instructing each operation of pan, tilt, and zoom. Insert and send in bulk. Since this method is the same as the existing operation command system of the camera, it can be easily realized without modifying the camera side.

  The camera drive operation command output from the camera drive operation command generator 73 and the camera operation speed command signal added thereto are both transmitted from the telephone 72 installed on the receiving terminal 4 side via the telephone line network 8 to the network. Sent to the camera 2.

When the web server function unit 23 of the network camera 2 receives these signals, it processes them and supplies them to the drive operation unit 24. Therefore, the drive operation unit 24 drives each camera as shown in FIG. Pan, tilt and zoom operations are performed according to the operation command. In addition, during the operation, the camera is operated at the camera operation speed according to the camera operation speed command signal added to each command. Thereby, the network camera 2 can always maintain an appropriate camera operation speed according to each operation when performing pan, tilt, and zoom operations.
Since other control operations and operational effects are the same as those in the first embodiment, detailed description thereof is omitted here.

  As described above, in the second embodiment, when the fixed network camera 2 is used, the camera operator M3 who remotely operates the network camera 2 on the receiving terminal side, as in the prior art, receives the receiving terminal 4 Even if the camera operation speed is not instructed while viewing the image displayed on the liquid crystal monitor 41, the frame rate detector 5 and the camera operation speed indicator 6 can be used to select an appropriate camera operation speed according to the degree of deterioration of the frame rate. Is automatically set, so that it is possible to always obtain the optimum video quality.

Regarding the second embodiment, the following modifications and application examples can be considered.
(1) In the above-described second embodiment, as shown in FIG. 12, camera operation speed command signals corresponding to pan, tilt, and zoom operations specified by the camera drive operation command are sent to the camera drive operation command. However, instead of this, the camera operation speed is changed only when the frame rate detected by the frame rate detector 5 has changed from the current state, as shown in FIG. The command signal may be transmitted independently of the camera drive operation command.

  That is, as shown in FIG. 13A, the camera drive operation command generator 73 generates a camera operation speed command signal (indicated by asterisks in the figure) when performing pan, tilt, and zoom operations. The pan, tilt and zoom camera drive operation commands are transmitted to the network camera 2 before being transmitted. When the network camera 2 receives the camera operation speed command signal, the network camera 2 presets the pan, tilt, and zoom operation speeds to the designated operation speeds. Thereafter, when the pan, tilt, and zoom drive operation commands are sent from the receiving terminal 4 side, the drive operation unit 24, as shown in FIG. Pan, tilt and zoom operations are performed according to the operation speed. When the frame rate detected by the frame rate detector 5 changes from the current state, a camera operation speed command signal suitable for the change in the frame rate is output from the camera operation speed indicator 6, so that the camera drive The operation command generator 73 transmits this camera operation speed command signal to the network camera 2 separately from the camera drive operation command.

  In this way, each time the camera drive operation command generator 73 transmits a camera drive operation command, the camera drive operation command generator 73 does not need to add a camera operation speed command signal to these commands and transmit them all at once. The burden of signal transmission processing in the generator 73 is reduced, and the signal transmission time for the network camera 2 is shortened, so that the responsiveness of the camera operation can be improved.

(2) In order to quickly grasp the situation at the site, it may be necessary to perform panning, tilting, and zooming operations of the network camera 2 at the highest speed so that the field of view is directed to the target object. In that case, the pan, tilt, and zoom operation speeds are faster than the frame rate of the video transmitted over the Internet 3, so that the video is naturally distorted and the image quality deteriorates. Therefore, there is no point in transmitting such a video with degraded image quality to the receiving terminal 4 side.

  Accordingly, as shown in FIG. 14A, a camera high-speed operation command signal (indicated by a mark ● in the figure) is added to the camera drive operation command from the camera drive operation command generator 73 on the receiving terminal side and transmitted. In this case, as shown in FIG. 14B, the web server function unit 23 on the network camera side stops the frame update of the video when the received signal includes the camera high-speed operation command signal. The drive unit 24 executes pan, tilt, and zoom operations at a high speed based on the camera drive operation command and the camera high-speed operation command signal. Then, the Web server function unit 23 resumes the video frame update immediately after the drive operation unit 24 stops the high-speed pan, tilt, and zoom operations.

  This eliminates the need for the network camera 2 to transmit meaningless video to the receiving terminal 4 side, thereby reducing the burden of video transmission processing of the network camera 2 and the Internet 3 being crowded with unnecessary information. Such troubles can be avoided.

(3) In the second embodiment, the camera operation speed notification means 7 transmits a camera operation speed command signal and a camera drive operation command to the network camera via the telephone line network 8. In this way, as in the case of the first embodiment, since the feedback delay is reduced and the delay amount is stable, the camera operation speed can be always instructed in real time, which is convenient. Instead of using such a telephone line network 8, it is also possible to transmit to the network camera 2 via the Internet 3. In this case, the communication cost when transmitting the camera operation speed command signal and the camera operation command can be reduced as compared with the case where the telephone line network 8 is used.

  The present invention is not limited to the configurations of the first and second embodiments, and various modifications can be made without departing from the spirit of the present invention.

1 is an overall configuration diagram of a video distribution support system according to Embodiment 1 of the present invention. It is a side view which shows the state which attached the frame rate detector to the liquid crystal monitor of the receiving terminal which comprises the system. It is a side view which expands and shows the sensor part of the frame rate detector. It is a top view which shows the state which attached the sensor part of the frame rate detector to the liquid crystal monitor of the receiving terminal. It is explanatory drawing in the case of detecting the illumination intensity change of the time code contained in the video signal from a network camera by the sensor part of a frame rate detector. It is a time chart which shows the temporal illumination intensity change of the time code detected by the sensor part of the frame rate detector. It is a flowchart which shows the procedure until it produces | generates a camera operation speed command signal based on the illumination intensity change signal of the time code detected by the frame rate detector. It is explanatory drawing which shows an example of the corresponding | compatible table which matched previously the detected frame rate and the appropriate operation speed of a network camera. It is explanatory drawing which shows an example of the corresponding | compatible table which matched the camera operation speed command signal and the audible sound which has various sound patterns. It is a whole block diagram of the video delivery assistance system in Embodiment 2 of this invention. It is explanatory drawing which shows an example of the corresponding | compatible table which matched previously the detected frame rate and the appropriate operation speed of a network camera. In Embodiment 2 of the present invention, an example of a signal pattern in which a camera operation speed command signal is added to a camera drive operation command and transmitted from the receiving terminal side and an operation procedure on the network camera side based on this signal are schematically shown. It is explanatory drawing shown. In Embodiment 2 of the present invention, a signal pattern in which a camera operation speed command signal is added to a camera drive operation command and transmitted from the receiving terminal side, and another example of the operation procedure on the network camera side based on this signal are schematically shown. FIG. In Embodiment 2 of the present invention, a signal pattern in which a camera operation speed command signal is added to a camera drive operation command and transmitted from the receiving terminal side, and yet another example of the operation procedure on the network camera side based on this signal It is explanatory drawing shown typically.

Explanation of symbols

1 video distribution support system, 2 network camera,
3 Internet (communication network), 4 receiving terminals,
5 Frame rate detector (frame rate detection means),
6 Camera operation speed indicator (camera operation speed instruction means),
7 Camera operation speed notification means, 71 Voice synthesizer, 72 Telephone,
73 Camera drive operation command generator, 8 telephone network, 9 telephone,
M1 camera operator, M2 receiving terminal side caller, M3 camera operator,
TB1 correspondence table, TB2 correspondence table, TB3 correspondence table.

Claims (7)

A network camera that captures video and transmits it to a communication network, and a receiving terminal that receives a video signal distributed from the network camera via the communication network,
The receiving terminal includes a frame rate detecting means for detecting a frame rate of the received video, and a camera operation speed indicating means for instructing an appropriate camera operating speed of the network camera corresponding to the frame rate detected by the frame rate detecting means. And a camera operation speed notification means for notifying the network camera or the operator of the camera operation speed instructed by the camera operation speed instruction means, and the frame rate detection means It detects the change in illuminance of the time code included in the video from the network camera displayed on the monitor screen of the terminal, and detects the frame rate from the change in illuminance. Appropriate rate and network camera Has previously correlated correspondence table and work speed, is what determines the operating speed of the network cameras corresponding to a frame rate that is detected by the frame rate detecting means by referring to this correspondence table, characterized Video distribution support system. The network camera is portable, and the camera operation speed notification means converts the camera operation speed information instructed by the camera operation speed instruction means into an audio signal and operates the camera via a circuit switching network. The video distribution support system according to claim 1, wherein notification is sent to a telephone carried by a person. The network camera is of a portable type, and the camera operation speed notification means directly transmits information about the camera operation speed instructed by the camera operation speed instruction means to the network camera via the communication network. The video delivery support system according to claim 1, wherein: The network camera is of a fixed type, and the camera operation speed notification means includes information on the camera operation speed instructed by the camera operation speed instruction means together with a camera drive operation command for driving the network camera. The video distribution support system according to claim 1, wherein the video distribution support system transmits the image data to the network camera via a circuit switching network. The camera operation speed notification means transmits camera operation speed information corresponding to pan, tilt, and zoom operations specified by the camera drive operation command in addition to the camera drive operation command. The video distribution support system according to claim 4, wherein: The camera operation speed notification means is configured to obtain information on camera operation speeds corresponding to pan, tilt, and zoom operations specified by the camera drive operation command from the current state of the frame rate detected by the frame rate detection means. 5. The video delivery support system according to claim 4, wherein the video delivery support system transmits the command independently of the camera drive operation command only when the change occurs. When the network camera includes camera high-speed operation command information included in the camera operation speed information transmitted together with the camera drive operation command from the camera operation speed notification means, the network camera until the camera drive operation command is executed. The video delivery support system according to any one of claims 4 to 6, wherein the delivery of the video signal to the receiving terminal side is stopped during this period.

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