JPH09214884A - Video communication terminal and multi-spot video display system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily reproduce the past images displayed right before. SOLUTION: A video display terminal is provided with a video buffer 103 for storing images to be displayed, the images displayed on a monitor 107 are successively stored in one video buffer 103 and when the video storage area of the video buffer 103 is full, new images are stored in the video storage area where old images are stored. At the same time, since the images are continuously displayed from old images to new images stored in the storage area of the video buffer 103, the past preceding image is easily displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video communication terminal and a multipoint video display system, and more particularly to a multipoint video display for receiving a video transmitted from a video communication terminal arranged at a remote place and displaying the video. It is suitable for use in a system.

[0002]

2. Description of the Related Art FIG. 8 is a conceptual diagram of a conventional computer-based multipoint video display system. Further, FIG. 9 shows a display example of the monitoring unit.

In FIG. 8, video communication terminals 1202 and 120 are shown.
3, 1204, 1205, 1206 are network 1
The multi-point video display system is configured to be connected to the video communication terminal 120 and capable of mutually communicating video, audio and data between the video communication terminals. In addition, in FIG.
Reference numeral 01 is a communication terminal housing that controls the communication function.

The network 1120 is a bus type network such as Ethernet (trademark). In the following description, the second to fifth video communication terminals 1203 to 1206 transmitting video are referred to as video transmitting terminals, and the first video communication terminal 1202 displaying video is referred to as video receiving terminal. .

In FIG. 9, 1302, 1303, 13
Reference numerals 04 and 1305 are video display windows for displaying the images taken by the video cameras connected to the video transmission terminals 1203 to 1206 that make up the multipoint video display system.

The multipoint video display system shown in FIG.
Since it is assumed that the images transmitted from the four image transmission terminals are displayed, four first to fourth image display windows 1302, 1303, 1304, 1305 are provided.

[0007]

The image contained in the display of the monitoring unit shown in FIG. 9 changes every moment. Therefore,
When there is a part of interest in the image that is being watched, there is a problem that the displayed image changes while trying to look at the above-mentioned part of interest, and it cannot be confirmed.

In order to solve such a problem, there has been a system which records an image displayed on the monitor 1106 in an external storage medium such as a magnetic disk. However, in the case of the conventional system, in order to read and display the image from the external storage medium,
There is a problem that it takes a lot of time and labor to start another video display application.

Further, even after the image is displayed, there is a problem that it takes a lot of time and effort to find the part of the image which is worrisome. The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to easily reproduce a past video displayed immediately before.

[0010]

A video communication terminal of the present invention is a video communication terminal for receiving a video transmitted from a video communication terminal arranged at a remote place and displaying it on a monitor.
It is characterized by comprising a video storage means for storing the video displayed on the monitor and a video writing means for storing the video displayed on the monitor in the display order in the video storage means.

Another feature of the present invention is that
The video storage means has a storage area for a plurality of frames,
The video writing means is characterized by erasing an old video and storing a new video when the storage area of the video storage means is full.

Another feature of the present invention is that it has an instruction means for reading an image from the image storage means, and stores the image stored in the image storage means in response to an instruction to the instruction means. Further, it is characterized by further comprising video reading means for continuously reading from old video to new video and displaying on the monitor.

Further, the multipoint video display system of the present invention comprises a plurality of video transmission terminals for transmitting video and a video display terminal for receiving the video transmitted from the video transmission terminal and displaying it on a monitor. In a point image display system, an image storage unit for storing an image transmitted from the image transmission terminal and displayed on the monitor, and an image writing unit for storing the images displayed on the monitor in the display order in the image storage unit. And means.

Another feature of the present invention is that:
The video storage means has a storage area for a plurality of frames,
The video writing means is characterized by erasing an old video and storing a new video when the storage area of the video storage means is full.

Another feature of the present invention is that it has an instruction means for reading out an image from the image storage means, and stores an image stored in the image storage means in response to an instruction to the instruction means. The present invention is further characterized by further comprising video reading means for continuously reading from old video to new video and displaying on the monitor.

Another feature of the present invention is a video communication terminal for receiving a video image transmitted from a plurality of video communication terminals arranged at a remote place and displaying the received video image on a monitor as a multi-image. It is characterized by comprising a video storage means for storing the video displayed on the monitor and a video writing means for storing the video displayed on the monitor in the display order in the video storage means.

Another feature of the present invention is that the number of the image storage means is equal to the number of the multi-images.

Another feature of the present invention is that the video storage means has a storage area for independently storing video transmitted from the plurality of video communication terminals, and the video writing means includes a plurality of storage areas. With respect to each video transmitted from the video communication terminal, the old video is erased and a new video is written when the storage area is full.

Another feature of the present invention is that it has an instruction means for reading out an image from the image storage means for each of the image communication terminals, and image communication instructed according to an instruction to the instruction means. It is characterized by comprising a video reading means for continuously reading the video stored in the storage area for storing the video transmitted from the terminal from the old video to the new video and displaying the video on the monitor.

Another feature of the present invention is that the instructing means is present in the monitor corresponding to each of the multiple images.

[0021]

Since the present invention comprises the above technical means, when the video transmitted from the video communication terminal located at a remote place is received and displayed on the monitor, the video displayed on the monitor is always stored in the video storage means. If the user wants to view the video displayed on the monitor again by storing the video, the past video displayed immediately before can be easily displayed on the monitor by reading the video from the video storage means. It will be possible.

Further, according to another feature of the present invention, since a plurality of videos are sequentially stored in the video storage means, the past video displayed immediately before can be sequentially displayed on the monitor. .

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a video communication terminal of the present invention will be described below with reference to the drawings. In the video communication terminal of the present embodiment, the video receiving terminal is provided with a buffer for storing a plurality of frame videos and a reproducing means for reproducing the video stored in the buffer, so that the past displayed on the monitor is displayed. The video of can be played easily.

FIG. 1 is a block diagram showing the configuration of the video communication terminal of this embodiment. In FIG. 1, 101 is a CPU that controls the whole, 102 is a RAM, and 103 is the RA.
This is a part of the area of M102, and is an area used as a video buffer for storing the past image displayed immediately before.

Reference numeral 104 is a ROM in which a program for loading an OS (operating system) into the RAM 102, other programs and fixed data are recorded, 105 is an image compression / expansion circuit for compressing / expanding image data, and 106 is a display monitor. A video memory for storing image data to be displayed on 107. These are connected to the memory bus 108 so that data can be transferred to each other.

The memory bus 108 has an I / O bus 1
09 is connected to the I / O bus 109. A keyboard 110, a mouse 111, an external storage device (such as a hard disk) 112, a video input unit 114 for connecting a video camera 113, and a voice input unit for connecting a microphone 115. 116, an audio output unit 117 that supplies an audio signal to the speaker 118, a video camera control unit 119 that controls pan, tilt, and zoom of the video camera 113, and a network transmission / reception unit 120 that connects to the network 121.
Is connected.

The image input section 114 is a video camera 113.
The analog video signal output from the device is converted into a digital video signal and stored in the internal RAM. Voice input unit 116
Converts an analog voice signal from the microphone 115 into a digital voice signal and stores it in an internal RAM.

The CPU 101 has a memory bus 108 and I
The video data stored in the RAM of the video input unit 114 and the audio data stored in the RAM of the audio input unit 116 can be accessed via the / O bus 109.

The audio output unit 117 is provided with a RAM for temporarily storing audio data from the I / O bus 109.
The audio data stored in the AM is sequentially converted into an analog signal and output to the speaker 118.

In such a configuration, the CPU 10
A computer including the RAM 1, the RAM 102, and the ROM 103 configures various functions in the video communication terminal of the present embodiment.

That is, a video storage means for storing the video transmitted from the video communication terminal arranged at a remote place, a video writing means for storing the video to be displayed on the monitor in the display order in the video storage means, and the above. A video reading means for sequentially reading the video stored in the video storage means from the old video to the new video and displaying the video on the monitor is configured.

The video storage means has a plurality of storage areas. Further, the video writing means stores the new video in order in the area storing the old video when the storage area of the video storage means is full.

The video terminals 202 and 2 thus configured
As shown in FIG. 2, 03, 204, 205, and 206 are connected to a network 121 to form a multipoint video display system capable of communicating video, voice, and data with each other.

In FIG. 2, 201 is the CPU 1 of FIG.
01, RAM 102, ROM 104, image compression / expansion circuit 105, VRAM 106, memory bus 108, I / O bus 109, external storage device 112, video input unit 114, audio input unit 116, audio output unit 117, video camera control unit 119, It is a communication terminal housing including a network transmitting / receiving unit 120 and the like.

The network 121 is a bus type network such as Ethernet (trademark) in this embodiment, but the present invention is not limited to such a specific network. In this embodiment, the video communication terminal 20
3, 204, 205, and 206 are video transmission terminals.

Each of the video transmitting terminals 203 to 206 transmits a video to the video receiving terminal 202, and the video receiving terminal 2
By displaying the video transmitted from No. 02, it can be used as a multipoint video display system.

FIG. 3 shows an example of the screen of the monitor 107. In FIG. 3, reference numeral 313 denotes a camera operation interface, which includes operation buttons for shooting direction and magnification, and a camera name display field for displaying a control target. 302, 303,
Reference numerals 304 and 305 are video display windows that normally display images captured by the video camera 113 connected to each of the video transmission terminals 203 to 206 that make up the multipoint video display system.

In the present embodiment, as shown in FIG. 2, it is assumed that the images transmitted from the four image transmission terminals 203 to 206 are displayed. Therefore, the first to fourth four image displays are displayed. Windows 302, 303, 304, 305 are provided.

These video display windows 302, 30
3, 304, and 305 can also be used when reproducing and displaying a recorded video stored in the corresponding video transmission terminal device. Therefore, each video display window 30
Below 2, 303, 304, and 305, buttons for controlling playback (rewind button 306, playback start button 30)
7, fast forward button 308, playback stop button 309),
Switching button 310 for switching between recorded video and current video
Is arranged.

Further, in this embodiment, an immediately preceding reproduction button 311 for confirming the immediately preceding image is provided. Needless to say, as long as the screen of the monitor 107 has room, four or more video display windows can be set and arbitrary current video and recorded video can be displayed.

As is well known, by moving the mouse cursor 312 freely with the mouse 111 and performing a predetermined operation on the camera operation interface 313 and various buttons 306 to 310, the user gives a desired instruction. CP
It can be input to U101.

Next, the basic operation of the video transmitting terminals 203 to 206 for transmitting video and audio data via the network 121 will be described. Video input unit 114
Converts an analog signal output from the video camera 113 into a digital signal and expands it in a built-in RAM.

The CPU 101 uses the R in the video input unit 114.
The video data is read from the AM, expanded in the RAM 102, and the video data is packetized and output from the network transmission / reception unit 120 to the network 121. The packet is transmitted via the network 121, for example, to the first
Is transmitted from the video transmitting terminal 203 to the video receiving terminal 202.

When the network transmission / reception unit 120 of the video receiving terminal 202 detects that a packet has arrived from the network 121, it expands the packet in the internal RAM and notifies the CPU 101 of the reception of the packet. CP
The U 101 reads data from the RAM in the network transmission / reception unit 120 and expands it in the RAM 102. Then, the CPU 101 takes out the video data included in the packet and writes it in a predetermined position of the VRAM 106.

For example, when the video data is to be displayed in the first video display window 302, it is written in the address of the VRAM 106 corresponding to the first video display window 302. As a result, the video transmitted from the first video transmission terminal 203 is displayed in the first video display window 302 assigned to it.

In each of the video transmitting terminals 203 to 206, the voice input from the microphone 115 is converted into a digital voice signal by the voice input unit 116 and the internal R signal is transmitted.
Deployed to AM.

The CPU 101 uses the R in the voice input unit 116.
The voice data is read from the AM and expanded in the RAM 102. Then, the voice data is packetized and output to the network transmission / reception unit 120. The voice packet is
It is transmitted to the video receiving terminal 202 via the network 121. For example, it is transmitted from the first video transmission terminal 203 to the video reception terminal 202.

In the video receiving terminal 202, when the network transmission / reception unit 120 detects that a packet has arrived from the network 121, the network transmission / reception unit 120 sends the packet to the internal R
It is expanded to AM and the CPU 101 is notified of packet reception. The CPU 101 reads data from the RAM in the network transmission / reception unit 120 and writes it in the built-in RAM of the audio output unit 117.

The audio output unit 117 converts the audio data stored in the internal RAM into an analog signal, and the speaker 1
Output to 18. As a result, the sound from the video transmitting terminal is output to the video receiving terminal. Similarly, sound from another one video communication terminal or a plurality of video communication terminals is output.

The CPU 101 generates a camera control command according to the operation content in response to the operation of the button on the camera operation interface 313 by the mouse 111, and transmits the camera to be operated and the image to which this camera is connected. By designating a terminal, the camera control command is packetized and output from the network transmission / reception unit 120 to the network 121.

The designated video transmission terminal takes in a packet containing the camera control command from the network 121, and when it confirms that the packet contains the camera control command, it sends the camera control command to the video camera control unit. 119.

The video camera control section 119 pans the video camera 113 according to the input camera control command.
Control tilt and zoom. In this way, the video camera 113 connected to another terminal device can be operated via the network 121.

As described above, the video transmitting terminals 203 ...
While remotely controlling the video camera 113 connected to 206, the image transmitted from another point can be viewed at the point where the image receiving terminal 202 is installed.

Next, the operation of the video transmission terminal will be described with reference to FIGS. Video camera 113
From the video input section 114
Stored in AM.

The CPU 101 controls the RA of the video input unit 114.
Read data from M (Step 401). Then, the read image data is compressed using the image compression / expansion unit 105 and divided into a size that can be sent through the network 121 (Step 402). Next, add a header such as an address to packetize (Step 40
3) Then, the packetized image data is transmitted (Step 404).

Next, the flow chart of the video receiving terminal will be described.
As shown in FIG. The packet sent from the video sending terminal is
It flows through the network 121, and the network transmitting / receiving unit 12
RAM received in the network transceiver unit 120
Is expanded to (Step 501).

The network transmission / reception unit 120 is the CPU 1
Receive interrupt to 01. The CPU 101 reads the packet from the RAM in the network transmission / reception unit 120. Then, the header of the packet is extracted and converted into data, which is copied to the RAM 102 (Step 502). C
The PU 101 repeats this operation until data for one screen is collected.

When the data for one screen is collected, the data is collected into one, and the image compression / expansion unit 105 is used to expand the image signal compressed on the transmission side (Step 503).
It is displayed on 07 (Step 504).

Then, the displayed image data is copied to the video buffer 103 (Step 505) and the buffer point is changed (Step 506). The change of the buffer point in Step 506 of FIG. 5 will be described with reference to FIG. In this example, description will be made assuming that the video buffer has three frames.

In FIG. 6, reference numerals 605 to 607 indicate that the storage area of the video buffer 103 is divided into three parts, each of which is a video buffer for one frame.
Reference numerals 602 to 604 are video buffer structures for managing the video buffers 605 to 607 for one frame.

These video buffer structures 602-6
The last entry of 04 is a pointer indicating the beginning of the next video buffer structure. The middle entry of the video buffer structures 602 to 604 is a pointer indicating the head of the video buffers 605 to 607 for one frame. The first entry in the video buffer structures 602-604 is for storing side information.

Reference numeral 601 denotes a structure point variable which stores the start pointer of the video buffer structure to be written at present. These variables are provided for each image to be displayed. For example, in the example shown in FIG. 3, since four videos are displayed, four sets of these variables are provided.

When copying the buffer in Step 505 of FIG. 5, the pointer of the video buffer structure pointed to by the structure point variable 601 is checked, and the beginning of the video buffer is checked from the middle contents of the video buffer structure. , Write data from that location.

When changing the pointer of the buffer in Step 506 of FIG. 5, the pointer of the video buffer structure pointed to by the structure point variable 601 is checked, and the next entry of the video buffer structure from the last entry of the video buffer structure is examined. The pointer at the head of the structure is checked, and the pointer is stored in the structure point variable 601.

FIG. 6A shows a structure point variable 60.
1 indicates a pointer to the video buffer structure 602. By moving the pointer as described above,
As shown in FIG. 6B, the structure point variable 601 becomes as shown in the video buffer structure 603.

Next, reproduction of the immediately preceding image will be described with reference to FIGS. 3 and 7. In FIG. 3, for example, the immediately preceding reproduction start button 3 of the third video display window 305 is displayed.
When 11 is pressed, as shown in FIG. 7, the reproduction operation of the immediately preceding image is started (Step 701). Next, the video buffer structure is checked from the structure point variable 601 (Step 7
02).

Next, the head of the video buffer is checked from the video buffer structure (step 703). Then, the image data therein is displayed on the display portion of the fourth video display window 305 (Step 704). Next, the next linked video buffer structure is checked from the video buffer structure (Step 705). Then, it is determined whether or not the video buffer structure has the same contents as the structure point variable 601 (Step 706).

If the result of this determination is that they are the same, it means that the display of the immediately preceding video has ended, so the reproduction of the immediately preceding video is terminated (Step 707). Also,
As a result of the above judgment, if not, the next video buffer structure is set as the current video buffer structure, the process returns to Step 703 and the above-described operation is repeated.

As described above, in the present embodiment, the video display terminal 202 is provided with the video buffer 103 for storing a plurality of images for each video to be displayed, and the displayed video is one of the plurality of video buffers 103. When the video buffer 103 is full, the old video is stored in the video buffer 103.
It is configured to be stored in.

Further, by providing a display means for continuously displaying the contents of these video buffers 103 from old to new, it is possible to easily display the immediately preceding past video.

Although the multi-point video display system has been described as an example in the above embodiment, the present invention is not limited to the multi-point video display system as described above, and may be, for example, a TV conference system or a surveillance system. Can also be applied well.

In the above embodiment, the video buffer 103 having a storage area for 3 frames is prepared.
By adjusting the number of frames, the reproducible past video can be adjusted.

Further, in the present embodiment, the latest display image is always stored in the video buffer 103.
It may be configured to be stored in the video buffer 103 every other frame, every two frames, or at regular time intervals, and may be displayed at a timing matched thereto. In this way, the time of the reproducible past video can be adjusted without changing the size of the video buffer 103.

[0074]

As described above, according to the present invention, when a video transmitted from a video communication terminal located at a remote place is received and displayed on a monitor, the video displayed on the monitor is always stored in the video storage means. Since it is stored, if the video displayed on the monitor is desired to be viewed again, the past video displayed immediately before can be easily displayed on the monitor by reading it from the video storage means. it can.

According to another feature of the present invention, since a plurality of videos are sequentially stored in the video storage means, the past video displayed immediately before can be displayed sequentially on the monitor. It is possible to continuously re-display the past image displayed on the monitor on the monitor.

Further, according to another feature of the present invention, it is possible to independently read the immediately preceding display image and display a multi-image for the images respectively transmitted from the plurality of video communication terminals.

[Brief description of drawings]

FIG. 1 is a block diagram of a video receiving terminal and a video transmitting terminal that can realize the present invention, showing an embodiment of the present invention.

FIG. 2 is a diagram illustrating an overview of a multipoint image display system of the present invention.

FIG. 3 is a diagram showing a video display example of the video receiving terminal of the present invention.

FIG. 4 is a flowchart showing an operation of the video transmission terminal according to the embodiment.

FIG. 5 is a flowchart showing an operation of the video receiving terminal according to the embodiment.

FIG. 6 is a diagram for explaining an operation of switching a video buffer to be stored.

FIG. 7 is a flowchart showing an operation of reproducing the immediately preceding past video.

FIG. 8 is a diagram illustrating an overview of a conventional multipoint video display system.

FIG. 9 is a diagram showing a video display example of a conventional video receiving terminal.

[Explanation of symbols]

 101 CPU 102 RAM 103 Video Buffer 104 ROM 105 Image Compression / Expansion Circuit 106 Video Memory (VRAM) 107 Display Monitor 108 Memory Bus 109 I / O Bus 110 Keyboard 111 Mouse 112 External Storage Device 113 Video Camera 114 Video Input Device 115 Microphone 116 Voice Input device 117 Audio output unit 118 Speaker 119 Camera control circuit 120 Network transmission / reception unit 121 Network 302 First video display window 303 Second video display window 304 Third video display window 305 Fourth video display window 306 Rewind button 307 Playback start button 308 Fast-forward button 309 Playback stop button 310 Change button 311 Previous playback button

Claims (11)

[Claims] 1. A video communication terminal for receiving a video transmitted from a video communication terminal arranged at a remote place and displaying the video on a monitor, and video storage means for storing the video displayed on the monitor, and the monitor. A video communication terminal, comprising: a video writing means for storing the video to be displayed on the video storage means in the order of display. 2. The video storage means has a storage area for a plurality of frames, and the video writing means erases an old video and stores a new video when the storage area of the video storage means is full. The video communication terminal according to claim 1. 3. An image reading means for reading an image from the image storing means, wherein the image stored in the image storing means is continuously changed from an old image to a new image in response to an instruction to the instruction means. The image reading means for reading and displaying on the monitor is further provided.
Or the video communication terminal according to any one of 2. 4. A multipoint video display system comprising: a plurality of video transmission terminals for transmitting video and a video display terminal for receiving the video transmitted from the video transmission terminal and displaying the video on a monitor. Image storage means for storing the video transmitted from the computer and displayed on the monitor, and video writing means for storing the video to be displayed on the monitor in the display order in the video storage means. Multipoint video display system. 5. The video storage means has a storage area for a plurality of frames, and the video writing means erases an old video and stores a new video when the storage area of the video storage means is full. The multipoint video display system according to claim 4, wherein 6. An image reading means for reading an image from the image storing means, wherein the image stored in the image storing means is continuously changed from an old image to a new image according to an instruction to the instruction means. The image reading means for reading and displaying on the monitor is further provided.
Alternatively, the multi-point video display system according to any one of 5). 7. A video communication terminal for receiving a video transmitted from a plurality of video communication terminals arranged at a remote place and displaying the received video on a monitor as a multi-image, for storing the video displayed on the monitor. A video communication terminal comprising: a video storage means; and a video writing means for storing the video displayed on the monitor in the display order in the video storage means. 8. The video communication terminal according to claim 7, wherein the video storage means is provided in a number corresponding to the number of the multi-image videos. 9. The video storage means has a storage area for independently storing the video images transmitted from the plurality of video communication terminals, and the video writing means stores each video image transmitted from the plurality of video communication terminals. On the other hand, when the storage area is full, old video is erased and new video is written, and the video communication terminal according to claim 7. 10. A storage area, which has an instruction unit for reading out an image from the image storage unit for each of the image communication terminals, and stores a transmission image from the image communication terminal instructed according to an instruction to the instruction unit. The video communication terminal according to any one of claims 7 to 9, further comprising video read means for continuously reading the stored video from the old video to the new video and displaying the video on the monitor. . 11. The video communication terminal according to claim 10, wherein the instruction means is present on the monitor corresponding to each of the multiple images.