JP3088268B2 - Video server in video-on-demand system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video server in a video-on-demand system for transmitting a video program to a subscriber and enabling interactive control.
About the server .

[0002]

2. Description of the Related Art With the recent development of digital transmission technology and digital compression technology, video-on-demand (VO
A study on an interactive video service system for subscribers called D) has attracted attention and is expected to be widely used in the future. The VOD system, unlike the conventional broadcast-type CATV, is a system that allows a subscriber terminal of a subscriber to correspond to a video program on a one-to-one basis, thereby enabling interactive control.

Conventionally, as such a VOD system,
Proceedings of Iii Global Communications (Hartem Gaffer et al., Multimedia Server Zoo Design and Performance, Hatem Ghafir et al., "Multimedia servers-de
sign and performance ", Proceedings of IEEE GCOM '9
4, pp.886-890, Patent Number, 5,321,740, Nov. and
Dec., 1994).

FIG. 8 is a block diagram for explaining the overall configuration of such a VOD system. In FIG. 8, VO
The D system includes a plurality of subscriber terminals 51 and 52, an exchange 5
5, packet switching network 63, and video servers 69, 70
It is composed of The subscriber terminals 51 and 52 are connected to a switching center 55 via subscriber transmission lines 53 and 54, respectively. The exchange 55 and the video server 69 are connected to the video signal transmission line 19,
The switching center 55 and the video server 70 are also connected by video signal transmission lines 19 and 20. The subscriber terminals 51 and 52 are connected to an exchange 55 via subscriber transmission lines 53 and 54, and the exchange 55 is connected to video servers 69 and 7 via transmission lines 19 and 20 for video signals.
0 is connected to the first network for transmitting a video signal.

The switching center 55 and the packet switching network 63
Are connected by a control signal transmission line 67. further,
The video servers 69 and 70 are connected to the packet switching network 63 via control signal transmission lines 17 and 17, respectively.
The subscriber terminal is connected to the switching center 55 via the subscriber transmission lines 53 and 54, and the switching center 55 is connected to the control transmission line 67.
The packet switching network 63 is connected to the video servers 69 and 70 via the control signal transmission line 17 to form a second network for transmitting control signals.

The switching center 55 is composed of subscriber circuits 56 and 57, a switch 58, a switch control unit 59, a connection control unit 61, and a control signal receiving unit 62. The control signals from the subscriber terminals 51 and 52 are transmitted to the switching center 55 via subscriber transmission lines 53 and 54, respectively.
The control signal is transmitted to the control signal receiving unit 62 via 6, 57.

[0007] The control signal accepting section 62 receives the control signals from the subscriber terminals 51 and 52 and the video servers 69 and 70.
If the connection control signal is a connection control signal relating to the setting / cancellation of the connection for transmitting the video signal and the connection for transmitting the control signal, the control signal is transferred to the connection control unit 61.

[0008] When the connection control unit 61 receives the connection control signal from the control signal receiving unit 62, the video servers 69, 7 are controlled based on the connection control protocol.
0 and a connection control signal are exchanged and processed.

[0009] The subscriber terminals 51 and 52 and the video server 6
The connection for transmitting the video signal between the connection control unit 9 and the connection control unit 70 is realized by the switch control unit 56 changing the parameters of the switch 58 necessary for connection setting / cancellation based on the processing result of the connection control unit 61. .

A connection for transmitting a control signal between the subscriber terminals 51 and 52 and the video servers 69 and 70 is set / released in the packet switching network 63 based on a processing result of the connection control signal.

As described above, the video servers 69, 7
The video signal from 0 is transmitted to the transmission lines 19 and 2 for the video transmission line.
0 and transmitted to the subscriber terminals 51 and 52 via the switch 58. Further, the control signals from the subscriber terminals 51 and 52 are multiplexed by the control signal receiving unit 62 and transmitted to the control signal transmission line 6.
7, packet switching network 63, and control signal transmission line 1
The data is transmitted to the video servers 69 and 70 via the channels 7 and 17.

FIG. 9 shows the video servers 69 and 7 in FIG.
FIG. 3 is a diagram showing a detailed configuration of a 0. However, the blocks in FIG. 9 that are assigned the same numbers as those in FIG. 8 are the same as the blocks in FIG. The video servers 69 and 70 include a switch 1, a switch control unit 2, a connection control unit 3,
It comprises video signal accumulation / reproduction units 4, 5, 6, and a system control unit 71. The system control unit 71 includes interfaces 9, 11, and 18, a control signal processing unit 12, a service provision management unit 13, and a video signal storage / reproduction unit management unit 14. Control signals from the subscriber terminals 51 and 52 input from the control signal transmission line are sent to the control signal processing unit 12 via the interface 18.

When the input control signal relates to the connection control set by the switch 1, the control signal processing unit 12 sends the control signal to the connection control unit 3 via the interface 11. Further, the control signal processing unit 12 manages directory information indicating where the video program is stored in the video signal storage / reproduction units 4, 5, and 6, and the input control signal relates to the reproduction control of the video program. In this case, the control signal input based on the directory information is transferred to the video signal storage / reproduction units 4, 5, and 6 via the interface 9.

The service provision management unit 13 is based on the control signal input from the control signal processing unit 12, and requests the past video program, the video program currently being viewed, the operation status of the playback control command of the subscriber, and the future. Information on service provision such as a desired video program is managed for each subscriber.

Although not shown in the drawing, the video signal storage / reproduction unit management unit 14 includes video signal storage / reproduction units 4, 5,
6 manages, via the interface 9, the status of use of resources such as the disk storage and the disk input / output interface, and the number of video streams being reproduced and transmitted, and the video stream status such as the transmission rate.

As an example, video signal storage / reproduction units 4, 5,
6 stores video programs A, B, and C, respectively, and reproduces the video programs from the video server 69 according to the control signal from the subscriber terminal 51 and transmits the video programs to the subscriber terminal 51. Will be described. First,
A description will be given of how the video program A is transmitted to the subscriber terminal 51 when the subscriber terminal 51 requests the video program A.

When the control signal processing unit 12 receives a control signal notifying that the video program A is selected from the subscriber terminal 51, the video program A is stored in the video signal storage / reproduction unit 4 with reference to the directory information. Make sure that

Next, assuming that the connection between the subscriber terminal 51 and the video signal transmission line 18 has already been established by the switch 58 of the exchange 55 in accordance with the procedure described with reference to FIG. The video signal storage / playback unit 4 is sent to the connection control unit 3 via the interface 11.
And a connection setting between the video signal transmission line 19 and the video signal transmission line 19.

In response to an instruction from the control signal processing unit 12, the connection control unit 3 switches between the input and output of the switch 1 managed by itself, that is, the video signal storage / reproduction units 4, 5, 6 and the video signal transmission lines 19, 20. It is determined whether or not a connection between the video signal storage / reproduction unit 4 and the video signal transmission line 18 can be set by referring to the state of the connection between them, and the switch control unit 2 is driven according to the result, and this connection is established. Set.

When a connection is established between the video signal storage / reproduction unit 4 and the video signal transmission line 18, the connection control unit 3 reports to the control signal processing unit 12 via the interface 11 that the connection has been established. I do.

Further, the control signal processing unit 12 instructs the video signal storage / reproduction unit 4 via the interface 9 to secure resources of the video signal storage / reproduction unit 4 necessary for reproducing the video program A.

If the video program A can be reproduced, the video signal storage / reproduction unit 4 transmits the video program A to the control signal processing unit 12.
Report to

When the control signal processing unit 12 receives a report of connection establishment and reproducibility from each of the connection control unit 3 and the video signal storage / reproduction unit 4, the video signal A is transmitted to the subscriber terminal 51 via the interface 18.
Notify that playback is possible.

When the subscriber terminal 51 receives the notification from the control signal processing unit 12 as a control signal, the subscriber terminal 51 transmits a reproduction control command corresponding to “PLAY” of the video cassette recorder via the control signal transmission line 17 and the interface 18. The signal is sent to the control signal processing unit 12 via the interface 18.

When receiving the reproduction control command from the subscriber terminal 51, the control signal processing unit 12 transfers the command to the video signal storage / reproduction unit 4, and the video signal storage / reproduction unit 4 starts the video program A ("" PLAY ").

According to the above procedure, the video program A requested by the subscriber terminal 51 is transmitted to the subscriber terminal 51.

Next, a description will be given of a procedure in which the subscriber terminal 51 performs playback control other than "PLAY" while receiving the video program A.

While receiving the video program A, the subscriber terminal 51 transmits the control signal transmission line 17 and the interface 1
A playback control command such as “fast forward”, “rewind”, and “pause” is sent to the control signal processing unit 12 via the control unit 8.

When the control signal processing section 12 receives these reproduction control commands from the subscriber terminal 51, the control signal processing section 12 transfers them to the video signal accumulation / reproduction section 4, and the video signal accumulation / reproduction section 4
Executes the reproduction of the video program A according to the reproduction control command.

With the above procedure, the subscriber terminal 51 realizes the reproduction control of the video program A.

Further, a description will be given of a procedure for switching the video program for the subscriber terminal 51 to change the viewing from the video program A to the video program C.

When the control signal processing unit 12 receives a control signal from the subscriber terminal 51 to notify the change of the viewing to the video program C, the control signal processing unit 12 accumulates the video program A which has been viewed up to that time via the interface 9. The video signal storage / reproduction unit 4 instructs the reproduction of the video program A to stop. Then, the control signal processing unit 12 confirms that the video program C is stored in the video signal storage / reproduction unit 6 by referring to the directory information.

Next, the control signal processing unit 12 releases the connection between the video signal storage / reproduction unit 4 and the video signal transmission line 19 to the connection control unit 3 via the interface 11, and the video signal storage / reproduction unit 6 A change is instructed to set a connection between the transmission line 19 and the video signal transmission line 19. In response to a change instruction from the control signal processing unit 12, the connection control unit 3 switches between the input and output of the switch 1 managed by itself, that is, between the video signal storage and playback units 4, 5, and 6 and the video signal transmission lines 19 and 20. It is determined whether or not a connection between the video signal storage / reproduction unit 6 and the video signal transmission line 19 can be set up with reference to the state of the connection, and the switch control unit 2 is driven according to the result to set this connection. I do. Here, when a connection is established between the video signal storage / reproduction unit 6 and the video signal transmission line 19, the connection control unit 3 reports via the interface 11 to the control signal processing unit 12 that the connection has been established. I do.

Further, the control signal processing unit 12 instructs the video signal storage / reproduction unit 6 via the interface 9 to secure resources of the video signal storage / reproduction unit 6 necessary for reproducing the video program C.

When the video program C can be reproduced via the interface 9, the video signal storage / reproduction unit 6 reports this to the control signal processing unit 12.

When the control signal processing unit 12 receives the report of connection establishment and reproduction possible from each of the connection control unit 3 and the video signal storage / reproduction unit 6, the control signal processing unit 12 sends the video program C to the subscriber terminal 51 via the interface 18.
Notify that changes to have been completed.

When the subscriber terminal 51 receives the notification from the control signal processing unit 12 as a control signal, the subscriber terminal 51 transmits a reproduction control command corresponding to “PLAY” of the video cassette recorder via the control signal transmission line 17 and the interface 18. The signal is sent to the control signal processing unit 12 via the interface 18.

When receiving the reproduction control command from the subscriber terminal 51, the control signal processing section 11 transfers this to the video signal storage / reproduction section 6, and the video signal storage / reproduction section 6 starts the video program C ("" PLAY ").

According to the above procedure, switching from the video program A to the video program C is realized by the control signal from the subscriber terminal 51.

With the above configuration, the subscriber terminals 51, 5
In response to the control signal from the terminal 2, the video server 69, 70 sends a video program requested by the subscriber to the subscriber terminal 5.
1, 52, and the subscriber terminal 5
The video server 69,
70 can be controlled to realize the reproduction control of the video program and the switching of the video program.

[0041]

In the conventional VOD system, the playback of video programs in the video servers 69 and 70 can be controlled by the control signals from the subscriber terminals 51 and 52, and the video programs can be switched. Fulfills the purpose of providing basic interactive services to the video server using the video server, but has the disadvantage that it is difficult to provide a flexible VOD service because the function of the system control unit of the video server is insufficient. is there. Specifically, the following three points are cited as disadvantages.

First, the time from when the subscriber terminal requests a video program to when the video program A is transmitted to the subscriber terminal 51 is mainly that the video storage / reproduction unit can reproduce the video program. It depends on the time it takes to get into the state. This corresponds to, for example, the time required for a video tape cueing operation when viewing with a video cassette recorder. The response time of such a video storage / playback unit varies in length from less than one second to several tens of seconds, depending on the degree of concentration of requests, but it always occurs in video servers of any architecture. In this case, no service (video program) is provided in the response time of the video storage / playback unit, and both the service provider and the subscriber are wasted time.

Second, the reproduction control of the video program is performed by the control signal from the subscriber terminal. However, considering the operation of the service provider, it is not always preferable to permit the reproduction control for all the video programs. Not always. For example, the service provider's income may include an advertising fee from an advertising agency in addition to the viewing fee from the subscriber. That is, the program provider can obtain the advertisement fee by providing the advertisement information to the subscriber. Such advertisement is important for the service provider to smoothly operate the VOD service. Conventionally, however, the subscriber is provided with a playback control function such as "fast forward" or "rewind" regardless of the content of the video program. During the reception, the subscriber may skip the advertisement information and not view the advertisement information, and the advertisement efficiency is deteriorated.

Third, it is difficult to realize an operation in consideration of a reproduction control command from a subscriber terminal. For example, when "pause", "fast forward", and "rewind" in the playback control commands are transmitted from the subscriber terminal, the video server executes the playback control according to these commands. During the execution of the playback control, the subscriber terminal is informed that these commands are being executed and only displayed. The execution of these commands is considered to occur stochastically during the video program playback time, although the length of execution time varies depending on the behavior of the subscriber. However, the conventional system cannot cope with an operation mode using such a command execution time.

Therefore, the technical problem of the present invention is to solve the above-mentioned drawbacks and to flexibly cope with the operation mode, and therefore, a video-on-demand system with high added value.
Video server .

[0046]

[Means for Solving the Problems]

According to the present invention, a plurality of subscriber terminals and
The number of video servers and the plurality of video servers
A first method for transmitting a video program to a plurality of subscriber terminals
A network, the plurality of subscriber terminals and the plurality of
A second network for transmitting control signals transmitted and received between the video servers.
Video-on-demand configured with a network
In a video server in a video system,
Each of the video servers stores the video program.
In response to a control signal from each of the plurality of subscriber terminals,
A plurality of storage / playback means for playing back video,
High-speed reading of the program
The plurality of storage / playback units are used by the video program.
A plurality of high-speed storage / reproducing means whose reproduction is started quickly;
Video playback from storage and playback means and high-speed storage and playback means
Switching means for switching the program to a predetermined output port
And a control signal from each of the plurality of subscriber terminals
In response to the control signal, the plurality of storage / reproduction means and
And controlling the high-speed storage / reproduction means and the switching means
Control means, the control means comprising:
It is necessary to play the video program stored in the storage and playback means.
Response time from playback to playback start
Response time calculation means for calculating
In the video program stored in the reproducing means,
The response time calculated by the response time calculation means
Select a video program to play
Means for selecting the plurality of subscribers.
Control signal indicating a viewing request is received from each user terminal
And the plurality of high-speed storage / reproduction means and the switching means.
Controlled by the response time calculation means.
Response time, the video program selecting means
And sends the selected video program to the subscriber terminal.
And the control means determines that each of the plurality of subscriber terminals is
Service provision information indicating the video program you are watching
Service providing means for managing the plurality of subscribers
Control the playback state of the video program from each terminal
When a control signal indicating a command to
Said control over the video program transmitted at
A playback control frame that suspends execution of the command indicated by the signal.
And a control unit, wherein the control unit controls the plurality of subscriptions.
Command to control the playback state from each user terminal
When the control signal is received, the service provision management means is controlled.
Sends the command with reference to the service provision information
The video program currently viewed by the subscriber terminal
The video pros stored in multiple high-speed storage and playback means
Gram or not, and said plurality of high-speed storage and reproduction
When it is determined that the video program is stored in the means
The execution of the command is stopped and the plurality of high
It is a video program stored in the
If it is determined that the command is executed
Notification to the plurality of storage and reproduction control means as described above.
Video-on-demand systems
Observer is obtained.

Further, according to the present invention, any of the foregoing bi
In a video server in a video-on-demand system , the control means receives a control signal indicating a command for controlling a reproduction state of the video program from each of the plurality of subscriber terminals, and Playback control command detection means for identifying a plurality of commands indicated in the signal and detecting a command determined to be detected in advance, wherein the video program selection means is configured to allow the playback control command detection means to execute the determined command. A video-on-demand system which, when detected, selects a video program to be transmitted during the execution of this command.
The video server in the system is obtained.

Further, according to the present invention, any of the foregoing bi
In a video server in a video-on-demand system , the control unit further includes a service providing management unit that manages service providing information indicating a video program currently being viewed by each of the plurality of subscriber terminals. Video-on-demand system characterized by having means
Video server can be obtained.

According to the present invention, a plurality of subscriber terminals, a plurality of video servers, a first network for transmitting a video program from the plurality of video servers to the plurality of subscriber terminals, the subscriber terminal to the video-on-configured and a second network for transmitting control signals to be transmitted and received between the plurality of video servers
In a video server in a demand system , each of the plurality of video servers stores the video program, and stores a plurality of storage / reproducing means for reproducing the video program in response to a control signal from each of the plurality of subscriber terminals. A plurality of high-speed storage / reproduction means capable of reading the video program at a high speed and starting reproduction of the video program faster than at least the plurality of storage / reproduction means; and a video from the plurality of storage / reproduction means and the high-speed storage / reproduction means. Switching means for switching a program to a predetermined output port; input of control signals from each of the plurality of subscriber terminals; and a plurality of storage / reproduction means, high-speed storage / reproduction means, and the switching means corresponding to the control signals. Control means for controlling each of the plurality of subscriber terminals. A service providing management unit for managing service providing information indicating a currently viewed video program; and a control signal indicating a command for controlling a reproduction state of the video program received from each of the plurality of subscriber terminals. Playback control command determination means for suspending execution of the command indicated by the control signal with respect to the video program transmitted to the plurality of subscriber terminals, wherein the control means transmits a command for controlling the playback state from each of the plurality of subscriber terminals. Upon receiving the control signal shown in the figure, the video program currently viewed by the subscriber terminal which transmitted the command with reference to the service provision information managed by the service provision management means is stored in the plurality of high-speed storage and reproduction means. It is determined whether the program is a video program or not and stored in the plurality of high-speed storage / reproduction means. If it is determined that the video program is not the video program stored in the plurality of high-speed storage / reproduction means, the command execution is stopped. Video-on- data notifying the storage / playback control means of the
A video server in a command system is obtained.

Further, according to the present invention, a plurality of subscriber terminals, a plurality of video servers, a first network for transmitting a video program from the plurality of video servers to the plurality of subscriber terminals, video on configured and a second network for transmitting control signals to be received between the subscriber terminal, wherein the plurality of video servers
A video server in a demand system , wherein each of the plurality of video servers stores the video program and reproduces the video program in response to a control signal from each of the plurality of subscriber terminals; A plurality of high-speed storage / reproduction means capable of reading the video program at a high speed and starting reproduction of the video program faster than at least the plurality of storage / reproduction means; and a plurality of high-speed storage / reproduction means. Switching means for switching a video program to a predetermined output port; a control signal from each of the plurality of subscriber terminals; and a plurality of storage / reproduction means, high-speed storage / reproduction means, and the switching means corresponding to the control signal And control means for controlling Playback control command detecting means for identifying a number of commands and detecting a command determined in advance, and when the playback control command detecting means detects the determined command, the command is transmitted during execution of the command. A plurality of video program selection means for selecting a video program stored in the high-speed storage / reproduction means, wherein the control means receives a control signal indicating a command for controlling the reproduction state from each of the subscriber terminals. the controlling plural high-speed storage and reproduction means and the switching means, bi in a video-on-demand system characterized by sending a selected video program by the video program selected to said plurality of subscriber terminals
A video server is obtained.

[0052]

The video server of the present invention calculates another response time until the transmission of the video program requested by the subscriber terminal, and reproduces and transmits the video program at the response time, by enhancing the function of the system control unit of the video server. The playback control command is selected, and the playback is transmitted. After completion of the playback control, the video program can be switched to the requested video program. Since the validity / invalidity of the playback control command is determined after inquiring the service provision management unit, the playback control from the subscriber terminal can be restricted for each video program. When the playback control command is detected, the subscriber terminal transmitting the playback control command receives the playback control command. It is possible to switch the video program that signal.

[0053]

Embodiments of the present invention will be described below with reference to the drawings. However, in the drawings used in the following description, the components denoted by the same reference numerals as those in FIGS. 8 and 9 are the same as those acting as the components in FIGS. 8 and 9.

FIG. 1 is a block diagram showing the configuration of a video server according to the first embodiment of the present invention. As shown in FIG. 1, the video server 10A includes a switch 1, a switch control unit 2, a connection control unit 3, video signal storage and playback devices 4, 5, 6, a system control unit 7A, and a high-speed storage and playback device.
It is composed of a high-speed memory unit 8 as a stage .

The system control section 7A includes an interface 11, a control signal processing section 12, a service provision management section 13,
It comprises a video signal accumulation / reproduction unit management unit 14, a response time calculation unit 15, and a video program selection unit 16.

The control signals from the subscriber terminals 51 and 52 (FIG. 8) input from the control signal transmission line 17 are sent to the control signal processing unit 12 via the interface 18.

The high-speed memory section 8 stores the video program and reproduces the video program with a very short response time as compared with the video signal storage / reproduction sections 4, 5, and 6.

The control signal processing section 12 includes a subscriber terminal 51,
When the control signal relating to the request of the video program by the 52 is input, the response time calculation unit 15 starts the calculation of the response time until the requested video program is reproduced.

Upon receiving an instruction from the control signal processing unit 12, the response time calculation unit 15 controls the disk storage and disk input of each of the video signal storage and playback units 4, 5, and 6 managed by the video signal storage and playback unit management unit 14. The response time is calculated with reference to the use status of resources such as the output interface, the number of video streams being reproduced and transmitted, and the video stream status such as the transmission rate, and the response time is notified to the video program selection unit 16.

When the response time is notified from the response time calculation unit 15, the video program selection unit 16
From among the video programs stored in the high-speed memory unit 8, a video program that can be transmitted to the subscriber terminals 51 and 52 during this response time is selected.

When the video program selecting section 16 determines that the response time is extremely short and it is impossible to transmit within that time, the selection of the video program is stopped.

When there are a plurality of video programs that can be transmitted within the response time, the video program selection section 16 selects a video program according to, for example, a priority set in advance by a service provider. In this case, the service provider makes the video program selection unit 16 refer to the service provision information for each of the subscriber terminals 51 and 52 managed by the service provision management unit 13 and, based on this, the candidate of the video program to be transmitted at the response time. Is prepared for each of the subscriber terminals 51 and 52 in advance, so that the video program selecting unit 16 can select from video program candidates for each subscriber.

As described above, when the video program selecting section 16 determines the video program to be transmitted during the response time, it notifies the control signal processing section 12 of this.

When the control signal processing unit 12 is notified of the video program to be transmitted at the response time from the video program selection unit 16, the control signal processing unit 12 connects the high-speed memory unit 8 to the video signal transmission lines 19 and 20 via the interface 11. The connection control unit 3 is notified of the connection setting request. When a predetermined connection is set according to the procedure described in the conventional example, the control signal processing unit 12 instructs the high-speed memory unit 8 via the interface 9 to start reproduction.

When the transmission of the video program in the response time is completed, the high-speed memory unit 8 notifies the control signal processing unit 12 via the interface 9 of the end.

Then, the control signal processing unit 12 notifies the connection control unit 3 of a connection setting request related to the transmission of the video program previously requested by the subscriber terminals 51 and 52 via the interface 11 to the connection control unit 3, which will be described below with reference to the conventional example. A predetermined connection is set according to a procedure similar to the procedure.

Further, as described in the conventional example, the control signal processing section 12 notifies the subscriber terminals 51 and 52 (FIG. 8) that the requested video program can be reproduced.

As an example, a procedure for switching to the video program D stored in the high-speed memory unit 8 during the response time until the transmission of the video program A requested by the subscriber terminal 51 will be described. It is also assumed that the connection between the subscriber terminal 51 and the video signal transmission line 19 has already been established by the switch 58 of the exchange 55 according to the procedure described with reference to FIG.

When the control signal processing unit 12 notifies the response time calculation unit 15 that the subscriber terminal 51 has requested the video program A, the response time calculation unit 15 checks the usage status of the resources managed by the video signal storage and playback unit management unit 14. With reference to the status of the video stream and the video stream, the response time until the video program A is reproduced and transmitted to the subscriber terminal 51 is calculated, and the result is notified to the video program selection unit 16.

When notified of the response time from the response time calculation unit 15, the video program selection unit 16
It is determined whether or not the video program transmitted to the subscriber terminal 51 during this response time can be reproduced.

When the video program selecting section 16 determines that the reproduction is not possible during the response time, the video program selection is stopped, this is notified to the control signal processing section 12, and the above-described procedure is continued. After the response time, it is reproduced and transmitted by the subscriber terminal 51.

When the response time calculation section 15 decides to send the video program D at the response time, it notifies the control signal processing section 12 that the video program D is sent at the response time.

The control signal processing section 12 includes a high-speed memory section 8 for storing a video program D and a video signal transmission line 19.
The connection control request is notified to the connection control unit 3, and when this connection is set, the high-speed memory unit 8 is instructed via the interface 9 to start reproduction.

When the transmission of the video program D in the response time ends, the high-speed memory unit 8 notifies the control signal processing unit 12 via the interface 9 of the end.

Then, the control signal processing section 12 notifies the connection control section 3 of a connection setting request between the video signal storage / reproduction section 4 for storing the video program A and the video signal transmission line 18 via the interface 11, and
Hereinafter, this connection is set according to a procedure similar to the procedure described in the conventional example.

Further, as described in the conventional example, the control signal processing section 12 notifies the subscriber terminal 51 that the video program A can be reproduced, and the video program A subscribes according to the procedure described in the conventional example. Transmitted to the user terminal 51.

As described above, the subscriber terminals 51, 52
Calculates the response time until the requested video program is transmitted, selects another video program to be reproduced and transmitted during the response time, reproduces and transmits the selected video program, and switches to the requested video program after this is completed.

Further, in the above example, the reproduction of only one video program D during the response time has been described. However, the number of video programs reproduced during the response time may be plural as long as it is within the response time. I don't care.

FIG. 2 is a block diagram showing the configuration of the video server according to the second embodiment of the present invention. However, in the drawings used in the following description, the components denoted by the same reference numerals as those in FIGS. 8, 9, and 1 are the same as the components in these drawings.

The video server 10B includes a switch 1, a switch control unit 2, a connection control unit 3, video signal storage / reproduction devices 4, 5, 6, a system control unit 7B, and a high-speed storage
It comprises a high-speed memory unit 8 as a product reproducing means .

The system control section 7B comprises interfaces 9, 11, and 18, a control signal processing section 12, a service provision management section 13, a video signal storage / reproduction section management section 14, and a reproduction control command determination section 21.

The control signals from the subscriber terminals 51 and 52 input from the control signal transmission line 17 are sent to the control signal processing unit 12 via the interface 18.

When the input control signal is related to the connection control set by the switch 1, the control signal processing unit 12 sends the control signal to the connection control unit 3 via the interface 11.

When the video signal playback control command is input, the control signal processing section 12 stores which video program is stored in the video signal storage / playback sections 4, 5, 6 and the high-speed memory section 8 managed by itself. Playback control command determination unit 21 based on directory information
To the video signal storage / reproduction units 4, 5, 6 and the high-speed memory unit 8 via

The playback control command judging section 21 stores the video program currently viewed by the subscriber terminals 51 and 52 (here, targeting the terminal 51) which has sent the input playback control command to the service provision management section 13. Contact Here, the playback control command determination unit 21 makes an inquiry to the service provision management unit 13 and as a result,
If you have not received a particular video program,
The playback control command determining section 21 determines that the input playback control command is valid, and sends the command to the predetermined video signal storage / playback sections 4, 5, 6, and high-speed memory 8 designated by the control signal processing section 12 via the interface 9. Forward.

When the subscriber terminals 51 and 52 receive a specific video program as a result of the inquiry to the service provision management unit 13, the playback control command determining unit 21 invalidates the input playback control command. And the transfer to the predetermined video signal storage / reproduction units 4, 5, and 6 is not performed. On the other hand, the reproduction command judging section 21 operates similarly for the subscriber terminal 52.

The specific video program serving as a criterion for the reproduction control command deciding section 21 is, for example, advertisement information or movie preview information, and may be selected in advance by a service provider.

As an example, a procedure in a case where the service provider has set the subscriber terminals 51 and 52 receiving the video program stored in the high-speed memory unit 8 to determine that the reproduction control command is invalid. Will be described. Here, it is assumed that the subscriber terminals 51 and 52 (FIG. 8) are receiving the video program A of the video signal storage / reproduction unit 4 or the video program D of the high-speed memory unit 8, respectively.

When the playback control command of the video program A is input from the subscriber terminal 51, the control signal processing section 12 sends the playback control command from the subscriber terminal A to the playback control command determination section 21 based on the directory information. Send.

When the playback control command judging section 21 receives the playback control command from the subscriber terminal 51, it inquires the service provision management section 13 about the video program currently being viewed by the subscriber terminal 51. When the subscriber terminal 51 recognizes that the video program A is being received as a result of the inquiry to the service provision management unit 13, the playback control command determination unit 21 determines that the input playback control command is valid, and Is transferred to the video signal storage / playback device 4 designated by the control signal processing unit 12 via the control signal processing unit 12, and the playback control of the video program A is realized.

When the playback control command judging section 21 receives the playback control command from the subscriber terminal 52, the playback control command determining section 21 inquires the service provision management section 13 about the video program currently being viewed by the subscriber terminal 52.

Then, the reproduction control command judging section 21
When the subscriber terminal 52 recognizes that the video program D in the high-speed memory unit is being received as a result of the inquiry to the service provision management unit 13, it determines that the input reproduction control command is invalid, and sends it to the control signal processing unit 12. Notice. Upon receiving this notification, the control signal processing unit 12 notifies the subscriber terminal 52 that the reproduction control command cannot be currently executed.

As described above, the reproduction control command judging section 21
Since the subscriber terminal that has transmitted the playback control command input determines the validity / invalidity of the playback control command after inquiring the service providing management unit 13 of the video program currently being viewed. Reproduction control from the terminal can be restricted.

If the service provider determines in advance the number of transmissions of the playback control command from the subscriber terminals 51 and 52 for each video program, the playback control command determination unit 2
The number of reproduction control command transmissions permitted to the subscriber terminal for each video program can be limited by 1 to increase the added value of the service.

FIG. 3 is a block diagram showing the configuration of the video server according to the third embodiment of the present invention. However, in the drawings used in the following description, the components denoted by the same reference numerals as those in FIGS. 8, 9, 1, and 2 are the same as the components in these drawings. As shown in FIG. 3, the video server 10C includes a switch 1, a switch control unit 2, a connection control unit 3,
Video signal storage / reproduction devices 4, 5, 6, System control unit 7
C, and a high- speed memory section 8 as high- speed storage / reproduction means .

The system control unit 7C receives the signals from the interfaces 9, 11, and 18, the control signal processing unit 12, the service provision management unit 13, the video signal storage and reproduction unit management unit 14, the video program selection unit 16, and the reproduction control command detection unit 22. Be composed.

The control signals from the subscriber terminals 51 and 52 input via the control signal transmission line 17 are sent to the control signal processing unit 12 via the interface 18.

When the input control signal relates to the connection control set by the switch 1, the control signal processing unit 12 sends this to the connection control unit 3 via the interface 11.

The control signal processing section 12 manages directory information indicating where the video program is stored in the video signal storage / reproduction sections 4, 5, and 6. The input control signal is used to control the reproduction of the video program. If so, the control signal input based on the directory information is sent to the reproduction control command detection unit 22.

When the playback control command detecting section 22 detects that the input playback control command is a specific playback control command determined in advance by the service provider, the playback control command is designated by the control signal processing section 12. The received video program stored in the subscriber terminals 51 and 52 which sent the specified video signal storage / reproducing units 4, 5, 6 or the high-speed memory unit 8 and transmitted the reproduction control command to another video program. Is notified to the control signal processing unit 12 to switch to.

When the control signal processing unit 12 receives the notification from the reproduction control command detecting unit 22, the video signal selecting unit 16 sets the subscriber in the video program stored in the high-speed memory unit 8 while executing the reproduction control command from the video programs stored in the high-speed memory unit 8. Terminal 51,
52 to determine the video program to be sent.

When the video program selecting section 16 determines the video program to be transmitted during execution of the reproduction control command, it notifies the control signal processing section 12 of this.

When the video signal to be transmitted during the execution of the reproduction control command is notified from the video program selection unit 16 to the control signal processing unit 12, the high-speed memory unit 8 and the video signal transmission lines 19 and 20 are transmitted through the interface 11.
To the connection control unit 3. When a predetermined connection is set according to a procedure similar to the procedure described in the conventional example, the control signal processing unit 12 instructs the high-speed memory unit 8 via the interface 9 to start reproduction.

As an example, a procedure for transmitting a playback control command while the subscriber terminal 51 is receiving the video program A and switching to the video program D during execution of the command will be described. The connection between the subscriber terminal 51 and the video signal transmission line 19 has already been established by the switch 58 of the exchange 55, and the video signal storage / reproduction unit 4 for storing and reproducing the video program A by the switch 4 and the video signal transmission line 1
It is assumed that the connection between 9 has been established.

Assuming that the commands detected by the playback control command detecting section 22 are “fast forward” and “rewind”, when a “fast forward” command is sent from the subscriber terminal 51, the playback control command detecting section 22 Is detected and notified to the control signal processing unit 12. Therefore, the control signal processing unit 12 issues an instruction to the video program selection unit 16. When the video program selection unit 16 selects the video program D in the high-speed memory unit 8, the video program D is transmitted to the control signal processing unit 12
Notify to

When the video signal to be transmitted during the execution of the reproduction control command is notified from the video program selection unit 16 to the control signal processing unit 12, the control signal processing unit 12 connects the high-speed memory unit 8 and the video signal transmission line 19 via the interface 11. To the connection control unit 3. When a predetermined connection is set according to a procedure similar to the procedure described in the conventional example, the control signal processing unit 12 transmits the high-speed memory unit 8 via the interface 9.
To start the reproduction of the video program D.

The return from the video program D to the video program A is performed by the following method.

When the playback control command detecting section 22 detects a command (eg, a "PLAY" command) other than "fast forward" and "rewind" from the subscriber terminal 51 to the video program A while receiving the video program D, the playback control is performed. The command detection unit 22 notifies the control signal processing unit 12 to return the video program D received by the subscriber terminal 51 to the video program A. Then, the control signal processing unit 12 notifies the connection control unit 3 of a connection setting request between the video signal storage / reproduction unit 4 for storing the video program A and the video signal transmission line 19 via the interface 11.

When the connection is set in accordance with the same procedure as that described in the conventional example, the reproduction control command detecting section 22 causes the high-speed memory section 8 to stop reproducing the video program D, and stores and reproduces the video signal. A "PLAY" command of the video program A is sent to the unit 4, and the command is executed.

As another method for returning from the video program D to the video program A, the video program D
When the playback control command detection unit 22 detects a command (for example, a “PLAY” command) other than “fast forward” and “rewind” from the subscriber terminal 51 while receiving the Notifies the control signal processing unit 12 to return the received video program D to the video program A.

Next, when the control signal processing unit 12 is notified of the end of reproduction of the video program D from the high-speed memory unit 8 via the interface 9, the control signal processing unit 12
1, a connection setting request between the video signal storage / reproduction unit 4 for storing the video program A and the video signal transmission line 18 is notified to the connection control unit 3.

When the connection is set in accordance with the procedure described in the conventional example, the reproduction control command detecting section 22 causes the high-speed memory section 8 to stop reproducing the video program D, and causes the video signal accumulating / reproducing section 4 to transmit the video signal. The "PLAY" command of the program A is sent, and this is executed.

As described above, the reproduction control command detector 22
When a specific playback control command is detected, the video programs received by the subscriber terminals 51 and 52 that have sent the playback control command can be switched. Further, the first to third embodiments of the present invention described so far can be used in combination with each other.

FIG. 4 is a block diagram showing the configuration of a video server according to a fourth embodiment of the present invention. The system control unit 7A according to the first embodiment of the present invention and the system control unit according to the second embodiment of the present invention are described. 7B is provided with a system control unit 7D in combination with 7B.
However, in the drawings used in the following description, FIGS.
Components numbered the same as in FIGS. 2 and 3 are the same as those in these figures. Referring to FIG.
The video server 10D includes a switch 1, a switch control unit 2, a connection control unit 3, video signal storage and playback devices 4, 5, 6, a high- speed memory unit 8, which is a high- speed storage and playback unit ,
And a system control unit 7D.

The system control section 7D includes interfaces 9, 11, 18, a control signal processing section 12, a service provision management section 13, a video signal storage / reproduction section management section 14, a response time calculation section 15, a video program selection section 16, It is composed of a playback control command determination unit 21.

With this configuration, the subscriber terminal 5
Calculates the response time until the requested video program is transmitted by the first and second video programs, selects another video program to be reproduced and transmitted during the response time, reproduces and transmits the video program, and switches to the requested video program after the completion. In addition, the playback control command determination unit 21 inquires of the service providing management unit 13 about the video program currently being viewed by the subscriber terminal that has sent the input playback control command, and then determines whether the playback control command is valid / invalid. Therefore, the reproduction control from the subscriber terminal can be restricted for each video program, and the two effects of the first embodiment and the second embodiment of the present invention can be obtained.

FIG. 5 is a block diagram showing the configuration of a video server according to the fifth embodiment of the present invention. The system control unit 7A of the first embodiment of the present invention and the system control unit of the third embodiment of the present invention. It has a system control unit 7E obtained by combining the unit 7C. However, in the drawings used in the following description, components denoted by the same reference numerals as those in FIGS. 8, 9, 1, and 3 are the same as the components in these drawings. Referring to FIG. 5, the video server 10E includes a switch 1, a switch control unit 2, a connection control unit 3, a video signal storage and reproduction unit 4, 5,
6, a system control section 7E, and a high- speed memory section 8, which is a high-speed storage / reproduction means .

The system control unit 7E includes the interfaces 9, 11, and 18, the control signal processing unit 12, the service provision management unit 13, the video signal storage and reproduction unit management unit 14, the response time calculation unit 15, the video program selection unit 16, It is composed of a reproduction control command detector 22.

With this configuration, the subscriber terminal 5
The response time until the transmission of the video program requested by each of the video programs 1 and 52 is calculated using the response time calculation unit 15, and another video program to be reproduced and transmitted at the response time is selected using the video program 16 and reproduced. It can be switched to the requested video program after it has been sent, and when the playback control command detection unit 22 detects the input specific playback control command, the subscriber terminal 51 that has sent this playback control command, It is possible to switch the video program being received by 52, and the two effects of the first embodiment and the third embodiment of the present invention can be obtained.

FIG. 6 is a block diagram showing the configuration of a video server according to the sixth embodiment of the present invention. The system control unit 7B according to the second embodiment of the present invention and the system control unit according to the third embodiment of the present invention. There is a system control unit 7F obtained by combining the unit 7D. However, in the drawings used in the following description, components denoted by the same reference numerals as those in FIGS. 8, 9, 1, 2, and 3 are the same as the components in these drawings. Referring to FIG. 6, the video server 10F includes a switch 1, a switch control unit 2, a connection control unit 3, video signal storage / reproduction devices 4, 5, 6, a system control unit 7F, and a high-speed storage / reproduction unit.
It is composed of a high-speed memory unit 8 which is a raw means .

The system control unit 7F includes the interfaces 9, 11, and 18, the control signal processing unit 12, the service provision management unit 13, the video signal storage and reproduction unit management unit 14, the video program selection unit 16, the reproduction control command determination unit 21, The control signal processing unit 12 is connected to a playback control command determination unit 21, and the playback control command determination unit 21 is connected to the playback control command detection unit 22. The control command detector 22 is connected to the interface 18.

With such a configuration, the playback control command judging section 21 inquires of the service provision management section 13 about the video program currently being viewed by the subscriber terminal which has sent the input playback control command, and then outputs the playback control command. Since the validity / invalidity is determined, the reproduction control from the subscriber terminal can be restricted for each video program. Further, when the reproduction control command detection unit 22 detects the specific reproduction control command inputted, the reproduction control command is transmitted. The video programs received by the subscriber terminals 51 and 52 can be switched.
The two effects of the embodiment are obtained.

FIG. 7 is a block diagram showing the configuration of a video server according to the seventh embodiment of the present invention. The system controller 7A according to the first embodiment of the present invention and the video server according to the second embodiment of the present invention are shown in FIG. There is provided a system control unit 7G obtained by combining the system control unit 7B and the system control unit 7C according to the third embodiment of the present invention. However, in the drawings used in the following description, components denoted by the same reference numerals as those in FIGS. 8, 9, 1, 2, and 3 are the same as the components in these drawings. Referring to FIG. 7, the video server 10G includes a switch 1, a switch control unit 2, a connection control unit 3, video signal storage / reproduction devices 4, 5, 6, a high- speed memory unit 8 serving as high- speed storage / reproduction means , and a system control unit. 10G.

The system control unit 7G includes the interfaces 9, 11, and 18, the control signal processing unit 12, the service provision management unit 13, the video signal storage and reproduction unit management unit 14, the response time calculation unit 15, the video program selection unit 16, It comprises a control command determination unit 21 and a reproduction control command detection unit 22.

With this configuration, the subscriber terminal 5
The response time until transmission of the video program requested by each of the video programs 1, 52 is calculated by using the response time calculation unit 15, and another video program to be reproduced and transmitted at the response time is selected by using the video program selection unit 16, and this is selected. After the playback and transmission are completed, the video program can be switched to the requested video program. Moreover,
Since the playback control command determination unit 21 inquires the service provision management unit 13 of the video program currently being viewed by the subscriber terminal that has transmitted the input playback control command, and determines whether the playback control command is valid / invalid. Reproduction control from the subscriber terminal can be restricted for each program. Further, when the reproduction control command detecting section 22 detects the input specific reproduction control command, it is possible to switch the video program received by the subscriber terminals 51 and 52 which have transmitted the reproduction control command. The combined effect of the three effects of the first embodiment, the second embodiment, and the third embodiment can be obtained.

[0126]

As described above, according to the present invention, the response time until the transmission of the video program requested by the subscriber terminal is calculated, and another video program to be reproduced and transmitted during the response time is selected and reproduced. After sending the video program, the video program can be switched to the requested video program.

Further, according to the present invention, the playback control command judging unit inquires of the service providing management unit 115 about the video program currently being viewed by the subscriber terminal which has transmitted the input playback control command, and then checks the playback control command. Since the validity / invalidity is determined, the reproduction control from the subscriber terminal can be restricted for each video program.

Further, according to the present invention, when the reproduction control command detecting section detects the input specific reproduction control command, it is possible to switch the video program received by the subscriber terminal which has transmitted the reproduction control command. .

As described above, the video server of the present invention improves the function of the system control unit and enables flexible provision of a VOD service.

[Brief description of the drawings]

FIG. 1 is a configuration diagram for explaining a video server according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram for explaining a video server according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram for explaining a video server according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram for explaining a video server according to a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram for explaining a video server according to a fifth embodiment of the present invention.

FIG. 6 is a configuration diagram for explaining a video server according to a sixth embodiment of the present invention.

FIG. 7 is a configuration diagram for explaining a video server according to a seventh embodiment of the present invention.

FIG. 8 is a diagram for explaining an example of a conventional VOD system and a VOD system to which the video server of the present invention is applied.

FIG. 9 is a configuration diagram for explaining a conventional video server.

[Explanation of symbols]

Reference Signs List 1 switch 2 switch control unit 3 connection control unit 4, 5, 6 video signal storage / reproduction unit 7A, 7B, 7C, 7D, 7E, 7F, 7G, 71
System control unit 8 High-speed memory unit 9, 11, 18 Interface 10A, 10B, 10C, 10D, 10E, 10F, 1
0G, 69, 70 Video server 12 Control signal processing unit 13 Service provision management unit 14 Video signal storage / reproduction unit management unit 15 Response time calculation unit 16 Video program selection unit 17 Control signal transmission path 19, 20 Video signal transmission path 21 Reproduction control command determination unit 22 Reproduction control command detection unit 51, 52 Subscriber terminal 53, 54 Subscriber transmission line 55 Exchange 56, 57 Subscriber circuit 58 Switch 59 Switch control unit 61 Connection control unit 62 Control signal reception unit 63 Packet Switching network

Claims (5)

(57) [Claims] 1. A plurality of subscriber terminals and a plurality of video servers
And the plurality of subscriber terminals from the plurality of video servers.
A first network for transmitting video programs to
Transmission between the plurality of subscriber terminals and the plurality of video servers.
A second network for transmitting the received control signal.
ComposedVideo on demand systems
Video server  Each of the plurality of video servers is provided with the video program.
Control of each of the plurality of subscriber terminals.
A plurality of storage / playback means for playing back in accordance with a signal;
High-speed reading of the video program
At least the plurality of storage / reproducing means provide the video
A plurality of high-speed storage / playback means for quickly starting program playback;
The plurality of storage / reproduction means and the high-speed storage / reproduction means
Switch to switch the video program to the specified output port
Switching means and control signals from each of the plurality of subscriber terminals
And the plurality of storage / reproduction corresponding to the control signal.
Means and high-speed storage / reproduction means and the switching means.
And control means for controlling, wherein the control means is stored in the plurality of storage and reproduction means.
Requests playback of the video program and then starts playback.
Response time calculation to calculate the response time until
Means, and stored in the plurality of high-speed storage and reproduction means.
The response time calculation means in the video program
Video program to be played at the calculated response time
And a video program selecting means for selecting a program, wherein the control means requires a viewing / listening request from each of the plurality of subscriber terminals.
When the control signal indicating the request is received, the plurality of high-speed storage
By controlling the reproducing means and the switching means,
The response time calculated by the
The video program selected by the video program selection means
And transmitting the program to each of the plurality of subscriber terminals.
A command for controlling the playback state of the video program
When the control signal shown
Shown in the control signal for the video program to be
Control command judging means for canceling the execution of a set command
WithThe control means controls the re-connection from each of the plurality of subscriber terminals.
Receive control signals indicating commands to control the raw state
And the subscriber terminal that sent the command
Video program to the plurality of high-speed storage and playback means
If the video program is stored,
Command execution, and the plurality of high-speed storage / reproduction means
If the video program is not stored,
Commands to the plurality of storage and reproduction control means so as to execute the command.
Video on demand system characterized by notification
Video server in the system. 2. The control means further receives a control signal indicating a command for controlling a reproduction state of the video program from each of the plurality of subscriber terminals, and identifies the plurality of commands indicated by the control signal. And a playback control command detecting means for detecting a command determined to be detected in advance. The video program selecting means executes the command when the playback control command detecting means detects the predetermined command. bidet of claim 1, wherein the selecting the video program to be delivered between
Video server in an on-demand system. 3. The control means further comprises service provision management means for managing service provision information indicating a video program currently being viewed by each of the plurality of subscriber terminals. Video according to 1 or 2
A video server in an on-demand system. 4. A plurality of subscriber terminals and a plurality of video servers.
And the plurality of subscriber terminals from the plurality of video servers.
A first network for transmitting video programs to
Transmission between the plurality of subscriber terminals and the plurality of video servers.
A second network for transmitting the received control signal.
ComposedVideo on demand systems
Video server  Each of the plurality of video servers is provided with the video program.
Control of each of the plurality of subscriber terminals.
A plurality of storage / playback means for playing back in accordance with a signal;
High-speed reading of the video program
At least the plurality of storage / reproducing means provide the video
A plurality of high-speed storage / playback means for quickly starting program playback;
The plurality of storage / reproduction means and the high-speed storage / reproduction means
Switch to switch the video program to the specified output port
Switching means and control signals from each of the plurality of subscriber terminals
And the plurality of storage / reproduction corresponding to the control signal.
Means and high-speed storage / reproduction means and the switching means.
Control means for controlling each of the plurality of subscriber terminals.
Service provision information indicating the video program
Service providing and managing means, and the plurality of subscriber terminals
A command for controlling the playback state of the video program from each
When a control signal indicating a command is received,
The control signal for the video program transmitted during
Playback control command to stop the execution of the command indicated in
Determining means, wherein the control means controls the re-transmission from each of the plurality of subscriber terminals.
Receive control signals indicating commands to control the raw state
And service provision managed by the service provision management means.
The subscriber terminal that sent the command with reference to the information
The video program that is being watched has the plurality of high-speed storage
Whether it is a video program stored in the raw means
Is determined, and stored in the plurality of high-speed storage / reproduction means.
If the video program is determined to be
Command execution is stopped, and stored in the plurality of high-speed storage / reproduction means.
If it is determined that the video program is not loaded
The plurality of storages so as to execute the command.
Notifying the product reproduction control meansVideo O
Video server in an on-demand system. 5. A plurality of subscriber terminals and a plurality of video servers.
And the plurality of subscriber terminals from the plurality of video servers.
A first network for transmitting video programs to
Transmission between the plurality of subscriber terminals and the plurality of video servers.
A second network for transmitting the received control signal.
ComposedVideo on demand systems
Video server  Each of the plurality of video servers is provided with the video program.
Control of each of the plurality of subscriber terminals.
A plurality of storage / playback means for playing back in accordance with a signal;
High-speed reading of the video program
At least the plurality of storage / reproducing means provide the video
A plurality of high-speed storage / playback means for quickly starting program playback;
The plurality of storage / reproduction means and the high-speed storage / reproduction means
Switch to switch the video program to the specified output port
Switching means and control signals from each of the plurality of subscriber terminals
And the plurality of storage / reproduction corresponding to the control signal.
Means and high-speed storage / reproduction means and the switching means.
Control means for controlling a plurality of commands indicated by the control signal.
Command to identify the command and detect it in advance.
Reproduction control command detecting means, and the reproduction control command
When the detecting means detects the determined command,
A high-speed storage playback device that sends out while executing a command
Multiple videos to select video programs stored in columns
Program selection means, wherein the control means comprises:
A command for controlling the playback state is issued from each of the subscriber terminals.
Receiving the control signal shown in FIG.
Controlling the step and the switching means to
The video program selected by the
Characterized by sending to subscriber terminalsVideo on
Video server in demand system.