JP3359356B2 - Video storage and exchange 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 moving image storage and exchange system using a center-to-end communication mode for compressing the amount of information of a moving image, storing it, and then decoding and reproducing it. is there.

[0002]

2. Description of the Related Art A conventional center-to-end type still image based image storage service system configuration is shown in FIG.
FIG. 6 shows a system configuration of a moving picture videophone, and FIG. 7 shows an image transmission method used in the moving picture videophone.

In FIG. 5, a center 103 and a terminal 101 are connected via a communication network 102. In response to a connection request from a terminal or a host 110 in the center, a communication path is established via a communication network. When the communication path is established, the data of the guide screen of the still image is transferred from the center to the terminal, displayed on the monitor 106 of the terminal, and the user on the terminal side performs menu selection along the guide screen. When the image storage is selected, the image from the camera 105 and the sound from the handset 107 are respectively transmitted to the image encoding / decoding unit 10.
8. The host 1 is encoded by the audio encoding / decoding unit 109 and stored in the storage device 104 of the center 103 via the communication path.
It is stored under the control of 10. When the reproduction is selected, the encoded image / audio data stored in the storage device 104 of the center is read out, and the image encoding / decoding unit 108 and the audio encoding / decoding unit 109 of the terminal are read via the communication path. Then, the image data and the audio data are decoded, and the still image is output to the monitor 106 and the audio is output to the handset 107.

Here, the image is based on a still image,
Since encoding is performed in frame units, reading of the stored encoded video and audio data may be interrupted,
Even when the reading is completed and the state in which no image data is transmitted to the terminal 101 continues, there is no problem such as the disturbance of the image on the terminal side and the abandonment of the communication path due to the loss of synchronization.

[0005] On the other hand, the operation of a moving picture videophone is as follows. In FIG. 6, the camera 204 of the local terminal 201
The image input from the image encoding / decoding unit 208a
Performs encoding by inter-frame predictive encoding, and
9a. The audio signal input from handset 206a is encoded by audio encoding / decoding section 210a and input to multiplexing section 209a. Multiplexing unit 209a
Then, under the control of the control unit 207a, the coded image data, the coded audio data, and a control signal (hereinafter, referred to as an image control signal) for an image specified by the control unit 207a are multiplexed together to perform multiplexing. Then, the data is transmitted to the partner terminal 202 via the communication network 203.

[0006] The multiplexed data sent from the local terminal 201 is received by the multiplexing unit 209b and separated into an image control signal, coded image data, and coded audio data. The image control signal is transmitted to the control unit 207b, the encoded image data is transmitted to the image encoding / decoding unit 208b, and the encoded audio data is transmitted to the audio encoding / decoding unit 210b. The encoded image data that has been subjected to the inter-frame prediction encoding in the image encoding / decoding unit 208b is decoded and reproduced and output to the monitor 205b, and the encoded audio data is decoded by the audio encoding / decoding unit 21.
0b and output to handset 206b. The image control signal is processed by the control unit 207b.

Next, a method of transmitting a moving image will be described with reference to FIG. After the line connection is established between the control unit 207a of the local terminal 201 and the control unit 207b of the partner terminal 202, the communication capabilities (audio capability, transfer rate, , Video capability, etc.), and the communication mode is determined. Thereafter, the own terminal 201 issues a request to the other terminal 202 to transmit an updated screen serving as a reference screen for inter-frame prediction. Upon receiving this information, the control unit 207b of the partner terminal issues an update screen transmission instruction to the image encoding / decoding unit 208b, and the image encoding / decoding of the partner terminal 202 is performed.
The decoding unit 208b sends the updated screen to the terminal 201 on the local side. According to such a procedure, a good image can be viewed on the local terminal 201 at the earliest timing after the line connection. When the reproduced image is disturbed due to a scene change of the input image or the like, a screen freeze request is transmitted using the image control signal of the partner terminal 202, and during the disturbance, the local terminal 2
01 is frozen, and the frozen image is released at a timing when the reproduced image becomes clear to some extent.

[0008]

In the case where the moving picture videophone employing the inter-frame predictive coding shown in FIGS. 6 and 7 is applied to the system shown in FIG. Is established and the response time of the initial menu by the stored moving image stored in the center exceeds the specified value, the reproduction interruption time during the reproduction of the stored moving image message, or after the reproduction of the stored moving image message ends. If the duration exceeds the specified value, the terminal side does not send image data from the center side even though the center side has video capability. Then, it shifts to the re-capacity exchange phase by using the image control signal. For this reason, it is expected that the image storage system using the moving picture videophone will not operate stably.

[0009] CCITT Recommendation H. When an image storage service is to be realized by using a video telephone according to H.242, a communication path is established with the center, and when the center attempts to transmit an initial menu based on the stored moving image, Depending on the response time, the terminal may reset the synchronization establishment and enter the re-capability exchange phase, assuming that the specified value has already been exceeded.

[0010] When the reproduction of the stored message is completed and the thinking time of the terminal user until the next selection is made becomes long, the image data transmission from the center during that time is not performed, so that the synchronization establishment is reset. There is a problem that a case occurs.

The present invention has been made in view of the above points, and has as its object to provide a moving image storage and switching system which does not limit the initial menu response time after connecting to the center and the thinking time of the terminal user. I have.

[0012]

According to the present invention, encoding means for encoding an input image, and first transmitting means for multiplexing the encoded image with encoded voice or control data and transmitting the multiplexed image and control data. First receiving means for receiving the multiplexed data and separating it into coded images, coded audio, and control data; means for decoding the received coded images; A second receiving means for receiving an image transmitted from the first transmitting means, comprising a terminal having a decoding means, a first transmitting means, and a first controlling means for controlling the first receiving means; Means for storing the encoded image and sound received by the means and the second receiving means, reading means for reading the stored encoded image and sound,
A center provided with second transmitting means for transmitting the read coded image and voice, and second control means for controlling the storing means and the reading means; In the center-to-end type moving image storage and switching system connected via a communication network, the first control means of the terminal and the second control means of the center follow the establishment of a communication path via the communication network. CCITT Recommendation H. 24
In the capability exchange procedure according to 2, the field from the second control means
Video indicating that image data should not be sent
After the capability exchange is performed under the state where the off command is transmitted, and the communication between the terminal and the center becomes possible,
If there is image data to be sent to the center,
The image data is transmitted after transmitting the video-on command instructing that the image data is also transmitted, and when the transmission of the image data is completed, the procedure for transmitting the video-off command again is performed to the second control means. I am preparing for it.

[0013]

According to the present invention, following the establishment of a communication path between a terminal and a center, the CCITT Recommendation H.264 is used. In the capability exchange procedure according to H.242, the capability exchange is performed from the center side with video off (no video signal is transmitted), and when image data can be transmitted from the center side, a video on command is transmitted to the terminal side. The image data is transmitted, and when the transmission of the image data is completed, a video off command is transmitted. This prevents reset of synchronization establishment on the terminal side.

[0014]

Embodiments of the present invention will be described below in detail. FIG. 1 shows the configuration of a moving image storage and switching system according to the present invention.
CITT Recommendation H. FIG. 2 shows the frame configuration of H.221, and FIGS. 3 and 4 show an image transmission method between the center and the terminal.
3 and 4 together show one figure, and FIG. 4 shows the processing subsequent to FIG.

In FIG. 1, reference numeral 401 denotes a moving picture videophone;
402 is a center and 403 is a communication network. The video videophone 401 includes a camera 404, a monitor 405, a handset 406, a control unit 407, and an image encoding / decoding unit 40.
8, a voice encoding / decoding unit 410 and a multiplexing unit 409. The center 402 includes a control unit 411 and a multiplexing unit 41.
2, a storage device 413.

In FIG. 2, reference numeral 501 denotes a multiplexing unit 409,
CCITT recommendation H.412 assembled at H.412. 221, a frame synchronization signal (FA)
S) and 503 are bit rate assignment signals (BAS) used for negotiation of terminal capabilities and communication conditions. Reference numeral 504 denotes sub-channels (encoded image data, encoded audio data, and data obtained by multiplexing general data);
Reference numeral 05 denotes a frame configuration when two ISDN basic interfaces are used.

Referring to FIG. 1 and FIG. 2, an outline of the operation of a moving image storage and switching system using a moving picture videophone will be described.
Communication network 403 from video telephone 401 to center 402
After the communication path is established, the control unit 407 in the moving picture videophone and the control unit 411 in the center use the BAS shown in FIG. Image communication to the center 402 is performed according to an instruction from the control unit 407. That is, a moving image from the camera 404 on the video videophone 401 side is subjected to inter-frame prediction coding by the image coding / decoding unit 408. The encoded image data is input from the handset 406, and is encoded by the audio encoding / decoding unit 41.
Multiplexed together with the coded audio data coded with 0 and the image control signal from the control unit 407 in the multiplexing unit 409,
The data is transmitted to the multiplexing unit 412 in the center 402 via the communication network 403. On the center side, the data obtained by multiplexing the image, sound, image control signal, and the like received by the multiplexing unit 412 is shown in FIG. Frame configuration 5 shown
01 or 505 is stored in the storage device 413 as an appropriate file as it is. Video Telephone 40
If there is no storage instruction from one user, the received data is discarded by the multiplexing unit 412.

The stored data is read from the storage device 413 in accordance with an instruction from the control unit 411 which has received a request from the user of the videophone, and the multiplexing unit 41 in the center.
2 If necessary, the control unit 411 rewrites the image control signal stored as it is from the moving picture videophone 401 to new information and transmits it to the moving picture videophone 401 via the communication network 403 when necessary. In the moving picture videophone 401, data obtained by multiplexing images, sounds, image control signals, and the like transmitted from the center are separated by a multiplexing unit 409 into coded image data, coded audio data, and image control signals. The encoded image data is sent to an image encoding / decoding unit 4
08, the encoded audio data is encoded by the audio encoding / decoding unit 41.
0, the image control signal is transferred to the control unit 407. The encoded image data is transmitted to the control unit 40 by the image encoding / decoding unit 408.
In accordance with the instruction from 7, the moving image is decoded and reproduced, and displayed on the monitor 405. The encoded audio data is decoded and reproduced by the audio encoding / decoding unit 410, and is output from the handset 406. In this way, messages from the videophone can be stored in the center, or the stored messages can be searched and read.

Next, the operation of the basic part of the present invention will be described in detail. 3 and 4 show an image transmission method using a moving image between the center and the terminal. In the figure, after a line connection is established between the moving picture videophone 401 and the center 402 via the communication network 403, the above-described BA is transmitted between the control section 407 on the moving picture videophone side and the control section 411 on the center side.
Both communication capabilities are exchanged using S503. At this time, the video capability is turned off from the center 402 and negotiation is executed. As a result, it is possible to notify the moving picture videophone 401 that there is no image capability to transmit from the center 402 to the moving picture videophone 401 immediately after the communication path is established. As a result, the line connection between the moving picture videophone 401 and the center 402 is completed, the capacity exchange is completed, and the synchronization for the image communication between the moving picture videophone 401 and the center 402 is established. Loss of synchronization due to a delay time until the menu screen is transmitted can be prevented. On the other hand, if the video is turned on, the synchronization is lost due to the transmission delay time of the above-mentioned initial menu screen, and communication becomes impossible.

Next, on the center 402 side, the control unit 411
The initial menu data is called from the storage device 413 according to the instruction. Before transmitting the initial menu data, the control section 411 transmits the multiplexing section 41 so as to transmit to the moving picture videophone side that the video capability of the center is to be turned on.
2 to the moving image videophone 401 using the BAS 503. On the moving picture videophone 401 side, the multiplexing unit 409 turns on the above-mentioned video on by the BAS
, An image encoding / decoding unit 408, a control unit 407
Then, the H.264 transmitted from the center 401 thereafter. 2
It operates to decode 21 frames of image data.
Thus, the initial menu data is transmitted. Eventually, when transmitting the last block of the initial menu, the control unit 411 transmits a screen freeze request to the moving picture videophone 401 by using the BAS 503 to prevent image disorder in the moving picture videophone 401. Further, since there is no more image data to be transmitted from the center 402 to the moving picture videophone 401, the moving picture videophone 401 is notified of the change of the image transmission capability to video off using the BAS 503. This prevents out-of-synchronization detection in the moving picture videophone 401.

Also, when the image data stored in the storage device 413 of the center 402 is read out, the same control as that of the transmission of the initial menu image data described above is performed, so that the center data is not lost. Two-end stored images can be transmitted.

[0022]

As described above, according to the present invention,
Since the video transmission capability is changed from the center side to the terminal depending on the presence or absence of image data to be transmitted, a storage and switching service using a moving picture videophone can be realized without causing the terminal side to lose synchronization.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a moving image storage and exchange system according to the present invention.

FIG. 2 shows a configuration of a stored image frame according to the present invention.

FIG. 3 shows an image transmission method between a center and a terminal according to the present invention.

FIG. 4 shows an image transmission method between a center and a terminal according to the present invention.

FIG. 5 shows a system configuration of a conventional image storage service based on still images.

FIG. 6 shows a system configuration of a moving picture videophone.

FIG. 7 shows an image transmission method used in a moving picture videophone.

[Explanation of symbols]

 101 terminal 102, 203, 403 communication network 103, 402 center 104, 413 storage device 105, 204, 404 camera 106, 205, 405 monitor 107, 206, 406 handset 108, 208, 408 image encoding / decoding unit 109, 210, 410 Voice encoding / decoding unit 110 Host 201 Local terminal 202 Destination terminal 207, 407, 411 Control unit 209, 409, 412 Multiplexing unit 501 Frame configuration 502 Frame synchronization signal (FAS) 503 Bit rate assignment signal (BAS) 504 Sub-channel 505 Frame configuration

Claims (1)

(57) [Claims] 1. An encoding means for encoding an input image, a first transmission means for multiplexing the encoded image with encoded voice or control data and transmitting the same, and a receiving means for receiving the multiplexed data. First receiving means for separating the encoded image, encoded sound and control data into a plurality of encoded data, decoding means for decoding the received encoded image, encoding means, decoding means and first transmitting means. A terminal having first control means for controlling the first receiving means; and a second receiving means for receiving an image transmitted from the first transmitting means and a second receiving means for receiving an image transmitted from the first transmitting means. Storage means for storing the encoded image and sound; reading means for reading the stored encoded image and sound; and second transmission means for transmitting the read encoded image and sound. And a second means for controlling the storage means and the reading means. And a center and a control unit, in the terminal and the center and is a center-to-end video image storage exchange system connected through a communication network, followed by the opening of the communication path through the communication network , CCITT Recommendation H.2 between a first control means of the terminal and a second control means of the center. 242, the image data is sent from the second control means.
No video off command has been sent
After the capability exchange is performed under the condition that the communication between the terminal and the center is enabled, if there is image data to be transmitted to the center side, the image data is also transmitted.
The image data is transmitted after transmitting the video on command instructing that the video data is transmitted. When the transmission of the image data is completed, the video off command is transmitted again in the second procedure.
A moving image storage and exchange system provided in the control means.