JPH0662049A - Animated picture mail system - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a moving picture mail system capable of favorably transmitting and receiving a moving picture mail composed of a video signal and an audio signal even between clients connected by a low-speed communication line. [Composition] In order to enable transmission / reception of video mail between each client (1, 2) connected by a low-speed communication line (4), video mail created in real time is communicated to each client (1, 2). It was equipped with a buffer memory (200) capable of transferring at the data transfer rate of the line. [Effect] Even when the data transfer rate of the communication line connecting each client is low and the real-time video mail cannot be transmitted and received between the clients, the data transfer rate of the communication line between the clients can be adjusted according to the data transfer rate. You can satisfactorily send and receive video mail.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a client / server system in which a server equipped with a storage device for accumulating mail and a plurality of clients are connected by a communication line. Regarding the video mail system to carry out.

[0002]

2. Description of the Related Art Conventionally, when a mail having a large amount of data such as an image (moving image, still image) file is sent and received between clients via a storage device of a server, a high speed dedicated line is used. And ISDN (In
integrated service digital network) or high-speed LAN
High speed line such as (Local Area Network) was used. Further, when a file having a small amount of data such as a text such as a document is transmitted and received as a mail, a low speed LAN such as Ethernet is used. Regarding the above-mentioned conventional technology, for example, Nikkei PC 19 of Nikkei BP
Featured in the May 11, 1992 issue of "E-mail that makes offices more airy" and Ohm's Computer & Network LAN featured in the May 1992 issue of "Multimedia LAN Introductory Examples." It has been described.

[0003]

In the above-mentioned conventional technique, a mail system using Ethernet, which is widely used as a LAN in an office or a premises, can send and receive a mail having a small amount of data such as text. However, since the transfer capacity of Ethernet is low for mail with a large amount of data such as moving images and still images, when writing or reading image data to or from the storage device (hard disk etc.) of the server, all emails are transferred in real time. Data cannot be transferred. Therefore, there is a problem in that it is not possible to satisfactorily send and receive video mail between clients connected by a low-speed communication line such as Ethernet.

An object of the present invention is to provide a moving picture mail system capable of favorably transmitting and receiving moving picture mail even between clients connected by a low speed LAN such as Ethernet.

[0005]

In order to solve the above problems, each client is provided with a storage device having a capacity capable of accumulating at least one video / audio data for moving image mail. Further, the following means are provided in each client.

(1) Real-time video / audio input processing means for capturing in real time each client a video signal and an audio signal transmitted as a moving picture mail supplied from a video camera, a microphone or the like.

(2) Real-time video / audio compression processing means for compressing in real time the video data and audio data of the moving image mail captured in real time to reduce the data transfer rate and the amount of data.

(3) Real-time storage means for storing the compressed video data and compressed audio data of the moving picture mail obtained by the real-time compression in the storage device of each client in real time.

(4) Communication speed reading means for reading the compressed video data and compressed audio data of the moving picture mail stored in the storage device of each client at a data transfer speed corresponding to the communication line.

(5) The compressed video data and the compressed audio data of the moving picture mail read by the communication speed reading means are transmitted to the server at a data transfer speed corresponding to the communication line, and the data corresponding to the communication line is transmitted from the server. Communication control means for receiving the compressed video data and compressed audio data of the video mail transferred at the transfer speed.

(6) The compressed video data and compressed audio data of the moving image mail transferred from the server at the data transfer rate corresponding to the communication line are stored in the storage device of each client at the data transfer rate corresponding to the communication line. Communication speed storage means.

(7) Real-time reading means for reading the compressed video data and compressed audio data of the moving picture mail stored in the communication speed storage means in real time.

(8) Real-time video / audio decompression for restoring the video data and audio data of the original video mail by expanding the compressed video data and compressed audio data of the video mail read by the real-time reading means in real time. Processing means.

(9) Real-time video / audio output processing means capable of displaying and reproducing the video data and the audio data obtained by expanding in real time on a display monitor and a speaker in real time.

The above problem can be solved by providing each client with the above means.

[0016]

In a client / server system in which a plurality of clients and servers are connected by a communication line with a low data transfer rate such as Ethernet, the client on the sending side sends a moving image mail to the receiving side via the server via the communication line. When transmitting to the client, the transmitting client operates as follows by the above means.
That is, the client on the transmitting side captures the video signal and the audio signal of the video mail transmitted by the real-time video / audio input processing means in real time, and the video data and the audio data captured by the real-time video / audio compression processing means in real time. Is compressed in real time to reduce the data transfer rate and the amount of data. Then, the real-time storage means temporarily stores the compressed video data and the compressed audio data in a storage device in real time, and the communication speed reading means stores the compressed video data and the compressed audio data from the storage device at a data transfer rate corresponding to a communication line. And the compressed video data and the compressed audio data read by the communication control means are transmitted to the server at a data transfer rate according to the communication line. Therefore, even if the communication line does not have a sufficient data transfer rate to transmit the video mail consisting of the compressed video data and the compressed audio data in real time, the client on the sending side can send the client on the receiving side to the client. Make sure to send video mail via the server at the data transfer rate according to the communication line.

When the client on the receiving side receives the moving image mail transmitted from the client on the transmitting side via the server via the communication line, the client on the receiving side operates as follows by the above means. That is, the client on the receiving side receives the moving picture mail composed of the compressed video data and the compressed audio data transferred from the server by the communication control means at the data transfer speed corresponding to the communication line, and received by the communication speed storage means. The compressed video data and the compressed audio data are temporarily stored in the storage device at a data transfer speed according to the communication line, and the real-time reading means operates to read the compressed video data and the compressed audio data from the storage device in real time. . Then, the compressed video data and compressed audio data read in real time by the real-time video / audio decompression processing means are expanded in real time to restore the original video data and audio data, and the real-time video / audio output means further displays a display monitor, The speaker operates to display and reproduce video signals and audio signals, respectively. Therefore, even if the communication line does not have a sufficient data transfer rate to transmit the video mail consisting of the compressed video data and the compressed audio data in real time, the client on the sending side can send the client on the receiving side to the client. It is possible to reliably send and receive the video mail via the server at the data transfer rate according to the communication line. That is, according to the present invention, the transmission and reception of the moving image mail is favorably performed between the clients through the low speed communication line such as Ethernet without using the high speed communication line.

[0018]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a system configuration diagram showing an embodiment of a moving image mail system according to the present invention. 2, 3 and 4 are schematic diagrams showing a data transfer state for explaining the operation of the moving picture mail system according to the present invention shown in FIG.

In FIG. 1, 1 is a first client,
2 is a second client, 3 is communication data storage means such as a file server, and 4 is communication for connecting the first client 1 and the second client 2 and the communication data storage means 3 to enable data transfer. A line (for example, Ethernet). The above-mentioned clients (the first client 1 and the second client 2) have exactly the same configuration, and the same reference numerals are given to the same portions. In the moving image mail system according to the present invention, at least a plurality of clients (the first client 1 and the second client 2) and the communication data storage means 3 are connected by the communication line 4, and each of the above-mentioned communication data storage means 3 is connected. The video mail is transmitted and received between the clients (the first client 1 and the second client 2). Hereinafter, as an example, a case will be described in which a moving image mail is transmitted and received from the first client 1 to the second client 2 via the communication data storage means 3. In this case, the moving picture mail system according to the present invention realizes transmission and reception of the moving picture mail by the following two processes. The first step is a step in which a moving picture mail is created by the first client 1 and the moving picture mail is transferred to and stored in the communication data storage means 3 by the communication line 4. The second step is a step of transferring the moving picture mail stored in the communication data storage means 3 to the second client 2 and receiving and reproducing the moving picture mail by the second client 2.

First, referring to FIGS. 1 and 2, the process of creating a moving picture mail by the first client 1 and transferring this moving picture mail to the communication data storage means 3 through the communication line 4 and storing it (the above-mentioned first step). ) Will be described.

In the first client 1 of FIG. 1, video signals and audio signals to be transmitted as moving picture mails are input from terminals 10 and 20, respectively. The video signal and the audio signal are continuously supplied in real time from, for example, a video camera or a microphone. Terminals 10, 2
The video signal and audio signal input from 0 are supplied to the real-time video / audio input processing means 30 and are converted from an analog signal to a digital signal in real time to be digital video data VD and digital audio data AD, which are real-time. Video / audio compression processing means 4
It is output to 0. For example, digital video data VD output from the real-time video / audio input processing means 30.
And the digital audio data AD together have a data transfer rate of x bytes / second and one moving image mail to be transmitted is T1 seconds, the digital video data VD and the digital audio data output from the real-time video / audio input processing means 30. The data transfer state including AD is shown in FIG. In FIG. 2 (a), the vertical axis represents the data transfer rate of the digital video data VD and the digital audio data AD, the horizontal axis represents the data transfer time, and the area of the shaded area is the total data of the video mail of T1 seconds to be transmitted. The amount is shown. Generally, the digital video data VD and the digital audio data AD are several tens of Mbytes / total.
With a data transfer rate of as long as a second, a video mail consisting of video and audio has a huge amount of data. For this reason,
As will be described later, in order to satisfactorily send and receive the moving picture mail via the communication line 4, it is necessary to reduce the data transfer rate of the moving picture mail and the data amount as much as possible.

Real-time video / audio compression processing means 40
Are digital video data VD and digital audio data A from the real-time video / audio input processing means 30.
In order to reduce the data transfer rate of D and the amount of data, a predetermined data compression process is performed in real time. At this time, the compressed digital video data retains the frame rate of the video signal input from the terminal 10 (for example, 30 frames / second when the video signal input from the terminal 10 is an NTSC signal). Compressed. The compressed digital audio data is also compressed so as to maintain continuity with the audio signal input from the terminal 20. Therefore, the real-time video / audio compression processing means 40 outputs the compressed digital video / audio data CD including the compressed digital video data in which the frame rate is maintained and the compressed digital audio data in which the continuity is maintained. Figure 2
(B) Compressed digital video for one video mail output from the real-time video / audio compression processing means 40.
The data transfer state of the audio data CD is schematically shown. The compressed digital video / audio data CD output from the real-time video / audio compression processing means 40 is the digital video data VD and digital audio data AD (FIG. 2) output from the real-time video / audio input processing means 30.
Compared with (a)), the data transfer time (T1 second) is not changed by the real-time compression process, but the data transfer rate is reduced to y bytes / second, and the total data amount shown by the shaded area is The data will be reduced. Generally, by the real-time compression processing of the real-time video / audio compression processing means 40, the data transfer rate after compression (y bytes / second) can be increased to about 150 kbytes / second.

The compressed digital video / audio data CD for one moving image mail output from the real-time video / audio compression processing means 40 is stored in the real-time storage means 50.
Is supplied to. The real-time storage means 50 is capable of storing at least one compressed digital video / audio data for moving picture mail in real time. Therefore,
The compressed digital video / audio data CD output from the real-time video / audio compression processing means 40 is transferred to the real-time storage means 50 in a data transfer state (data transfer rate y bytes / second, data It is accumulated in real time at a transfer time T1 second).

The compressed digital video / audio data CD for one moving image mail stored in real time in the real time storage means 50 is read by the communication speed reading means 60 according to the data transfer speed of the communication line 4. The data transfer rate is lower than the data transfer rate of z bytes / sec. If the data transfer speed of the communication line 4 is lower than the transfer speed y bytes / second required for real-time transfer of the compressed digital video / audio data CD for one moving image mail, the communication line 4 is used. The compressed digital video / audio data CD for one moving picture mail cannot be transferred to the communication data storage means 3 in real time. For example, when a plurality of clients are connected to the communication line 4 by using Ethernet which is generally popular, the effective data transfer rate of Ethernet is 100K.
It is about bytes / second. For this reason, in a low-speed communication line such as Ethernet, transmission / reception of a video mail between each client (the first client 1 and the second client 2) is performed at a frame rate of a video signal (when the video signal is an NTSC signal, 30 (Frame / second) and audio signal continuity cannot be maintained in real time. However, by providing each client (the first client 1 and the second client 2) with the real-time storage means 50 and the communication speed reading means 60 as described above, one moving image output from the communication speed reading means 60 is obtained. Compressed digital video / audio data TD for mail
Can be read at a data transfer rate z bytes / second (for example, about 100 Kbytes / second) lower than the data transfer rate of the communication line 4 according to the data transfer rate of the communication line 4. FIG. 2C schematically shows a data transfer state of the compressed digital video / audio data TD for one moving image mail output from the communication speed reading means 60. Compressed digital video output from the communication speed reading means 60
The audio data TD is the compressed digital video / audio data TD (see FIG. 2) supplied to the real-time storage means 50.
Compared with (b)), the total data amount indicated by the hatched area is not changed by the communication speed reading means 60 (y × T1 byte = z × T byte), but the data transfer rate is z byte / The data transfer time is reduced to T (=
y × T1 / z) seconds.

As shown in FIG. 2C, the data transfer rate lower than the data transfer rate of the communication line 4 is z bytes / second,
The compressed digital video / audio data TD for one moving image mail read from the communication speed reading means 60 in the data transfer time T (= y × T1 / z) seconds is the communication control means 7.
Supplied to zero. The communication control means 70 converts the compressed digital video / audio data TD for one moving image mail into a predetermined format so that it can be transferred through the communication line 4, and transfers the data according to the data transfer speed of the communication line 4. Speed z bytes / second, data transfer time T (= y × T1 /
In z) seconds, it is sent to the communication line 4 and transferred to the communication data storage means 3. Then, the communication data storage means 3 stores the transferred compressed digital video / audio data TD for one moving image mail in the storage device in the communication data storage means 3.

As is clear from the above description, the data transfer speed of the communication line 4 is low, and the compressed digital video / audio data CD for one moving picture mail cannot be transferred to the communication data storage means 3 in real time. Even if
In the video mail system of the present invention, each client (first
Since the client 1 and the second client 2) are provided with the real-time storage means 50 and the communication speed reading means 60, the data transfer speed (z bytes / second, for example, 100 Kbytes / second) according to the data transfer speed of the communication line 4
Second), the data transfer time (T seconds), and the compressed digital image for one video mail from the first client 1
The audio data TD can be reliably transferred and stored in the communication data storage means 3 while maintaining the frame rate of the video signal and the continuity of the audio signal. That is, according to the present invention, even if the communication line 4 is a low-speed communication line such as Ethernet, the moving image mail created by the first client 1 is continuously stored in the communication data storage means 3 in the frame rate of the video signal and the audio signal. It can be transferred and stored while retaining its sex.

In the above description, assuming that the data transfer rate of the communication line 4 is constant, as shown in FIG. 3C, the compressed digital video / audio data TD for one moving image mail from the first client 1 is obtained. A constant data transfer rate (z bytes /
Second), data transfer time (T seconds), communication data storage means 3
Transferred to. However, in general, the data transfer status of the communication line 4 changes depending on the traffic amount. For example, in FIG.
When the data transfer rate changes every moment as shown in FIG. 3A, when data can be transferred only intermittently as shown in FIG. 3B, and every moment data is transferred as shown in FIG. There are cases where the transfer rate changes and data can be transferred only intermittently. In the video mail system according to the present invention shown in FIG. 1, each client (first client 1 and second client 2) has a real-time storage means 5.
0 and the communication speed reading means 60 are provided, so that even if the communication line 4 is in any data transfer state as shown in FIG. The video / audio data TD can be read from the communication speed reading means 60 according to the data transfer state of the communication line 4, and can be reliably transferred and stored in the communication data storage means 3.

Next, referring to FIGS. 1 and 4, the process of transferring the moving picture mail stored in the communication data storage means 3 to the second client 2 and receiving the moving picture mail at the second client 2 ( The second process) will be described.

The compressed digital video / audio data TD for the one moving picture mail stored in the communication data storage means 3 is transferred from the first client 1 to the communication data storage means 3 by the communication line 4. As in the case of the transfer, the communication line 4 has a predetermined format and the format shown in FIG.
As shown in (a), data is transferred to the second client 2 at a data transfer rate (z bytes / second) and a data transfer time (T seconds) according to the data transfer rate of the communication line 4. The second client 2 in a predetermined format by the communication line 4
The compressed digital video / audio data TD for one moving image mail transferred to the original compressed digital video / audio data TD ′ for one moving mail by the communication control means 70 of the second client 2. (FIG. 4A) is converted back.

Communication control means 70 of the second client 2
The compressed digital video / audio data TD ′ for one moving image mail output from is supplied to the communication speed storage means 80. The communication speed storage means 80 has a capacity to store the compressed digital video / audio data TD for at least one video mail, and the compressed digital video / audio for one video mail output from the communication control means 70. The data TD 'is stored at a data transfer rate (z bytes / second) and a data transfer time (T seconds) according to the data transfer rate of the communication line 4, as shown in FIG.

Compressed digital video / audio data TD 'for one moving image mail stored in the communication speed storage means 80.
4 by the real-time reading means 90.
As shown in (b), the data transfer rate y bytes / second, which is faster than the data transfer rate of the communication line 4, the data transfer time T1
Read in real time in seconds. That is, the real-time reading means 90 outputs the compressed digital video / audio data CD ′ corresponding to the compressed digital video / audio data CD output from the real-time video / audio compression processing means 40 in the first client 1. It will be.

The compressed digital video / audio data CD 'output from the real-time reading means 90 is supplied to the real-time video / audio expansion processing means 100. The real-time video / audio decompression processing means 100 separates the compressed digital video data and the compressed digital audio data from the compressed digital video / audio data CD ′, and performs a predetermined decompression process on each in real time. ), The original digital video data VD 'and digital audio data AD' having a data transfer rate of x bytes / second and a data transfer time of T1 seconds are restored. Therefore, the digital video data VD output from the real-time video / audio input processing means 30 in the first client 1 and the digital video data VD ′ corresponding to the digital audio data AD are output from the real-time video / audio expansion processing means 100. The digital audio data AD 'will be output.

Real-time video / audio decompression processing means 10
Digital video data VD ′ and digital audio data AD ′ corresponding to one moving image mail from the client 1 output from 0 are supplied to the real-time video / audio output processing means 110. The real-time video / audio output processing means 110 can convert each of the supplied digital video data VD ′ and digital audio data AD ′ for one moving image mail from a digital signal to an analog signal in real time and display them on the display monitor 120. And a sound signal that can be reproduced by the speaker 130 is output in real time. Then, the video signal and the audio signal, which are output from the real-time video / audio output means 110 and constitute one moving image mail from the first client 1, are respectively displayed on the display monitor 120 and the speaker 1.
By supplying it to 30, one moving image mail from the first client 1 can be displayed and reproduced in real time.

As is clear from the above description, in the moving image mail system of the present invention, each client (first client 1 and second client 2) is provided with the communication speed accumulating means 80 and the real time reading means 90. , The compressed digital video / audio data TD ′ for one moving image mail from the first client 1 stored in the communication data storage means 3 is transferred at a data transfer rate (z Bytes / second) and data transfer time (T seconds) can be reliably transferred to and accumulated in the second client 2. Then, the second client 2 can decompress the compressed digital video / audio data TD ′ for one moving image mail from the first client 1 in real time, and one compressed mail image / audio data TD ′ from the first client 1 can be expanded. Video mail is restored and displayed in real time,
Can be played. That is, according to the present invention, even if the communication line 4 is a low speed communication line such as Ethernet, the moving image mail created by the first client 1 is communicated while maintaining the frame rate of the video signal and the continuity of the audio signal. The data can be transferred to the second client 2 via the data storage means 3, and the second client 2 can restore the moving picture mail from the first client 1 in real time for display and reproduction.

The data transfer state of the communication line 4 is shown in FIG.
In any case, the clients (first client 1 and second client 2) in the moving image mail system according to the present invention have the communication speed storage means 80 as shown in FIG.
And the real-time reading means 90, the compressed digital video / audio data TD 'for one video mail from the first client 1 stored in the communication data storage means 3 is stored in the communication line 4 as data. According to the transfer status, the data can be transferred to the second client 2 without fail, and can be stored in the communication speed storage means 80. Then, the compressed digital video / audio data CD ′ is output in real time from the real-time reading means 90 and decompressed to restore one video mail from the first client 1 in real time for display and reproduction. be able to.

The embodiment of the moving picture mail system according to the present invention shown in FIG. 1 has been described above. Next, a specific example of the real-time storage means 50, the communication speed reading means 60, the communication speed storage means 80, and the real-time reading means 90 in each client (first client 1 and second client 2) in FIG. Will be described.
FIG. 5 is a block diagram showing an embodiment of the real-time storage means 50, communication speed reading means 60, communication speed storage means 80, and real-time reading means 90. In FIG. 5, the real-time storage means 50 comprises a real-time write control unit 210 and a storage device 200. The communication speed reading means 60 is a communication speed reading control unit 220.
And a storage device 200. The communication speed storage unit 80 includes a communication speed writing control unit 230 and the storage device 200. The real-time reading means 90 includes a real-time reading control unit 240 and a storage device 200. further,
The storage device 230 is composed of a buffer memory such as a semiconductor memory or a hard disk, and is a compressed digital video / audio data CD for at least one moving image mail.
Has the capacity to store.

First, the real-time write controller 210
Real-time storage means 5 including the storage device 200
An example of No. 0 will be described with reference to FIG.

In FIG. 5, the compressed digital video / audio data CD for one moving image mail output from the real-time video / audio compression processing means 40 in each client of FIG. It is supplied to the device 200. At this time, the CPU 500 of each client outputs a write command signal for instructing the real-time write control unit 210 to write the compressed digital video / audio data CD for one moving image mail. Real-time write control unit 210
Is based on the write command signal from the CPU 500,
A write control signal RW for writing the compressed digital video / audio data CD for one moving image mail in real time is output to the storage device 200. Storage device 200
On the basis of the write control signal RW, the compressed digital video / audio data CD for one moving image mail is written in real time. As is clear from the above description, the real-time write control unit 210 and the storage device 200 can realize the real-time storage unit 50 shown in FIG.

Next, an embodiment of the communication speed reading means 60 composed of the communication speed reading control section 220 and the storage device 200 will be described with reference to FIG.

In FIG. 5, the compressed digital video / audio data CD for one moving image mail is written in real time in the real time storage means 50 composed of the real time write control unit 210 and the storage device 200, and then the CPU is operated. Outputs a read command signal for instructing the communication speed read control unit 220 to read the compressed digital video / audio data CD for one moving image mail. Based on the read command signal from the CPU 500, the communication speed read control unit 220 reads the compressed digital video / audio data CD for one moving image mail according to the data transfer speed of the communication line 4, and the read control signal TR. Is output to the storage device 200. Storage device 2
00 operates to read the compressed digital video / audio data CD for one moving image mail stored in the storage device 200 according to the data transfer speed of the communication line 4 based on the read control signal TR. Therefore, the compressed digital video / audio data TD for one moving image mail is output from the storage device 200 to the terminal 202 at a transfer rate according to the data transfer rate of the communication line 4, and communication is performed as shown in FIG. It is transferred to the communication data storage means 3 via the control means 70 and the communication line 4. As is clear from the above description, the communication speed read control unit 220 and the storage device 20.
By 0, the communication speed reading means 60 shown in FIG. 1 can be realized.

Next, an embodiment of the communication speed storage means 80 composed of the communication speed writing control unit 230 and the storage device 200 will be described with reference to FIG.

In FIG. 5, from the terminal 201, the communication data storage means 3 to the communication line 4 and the communication control means 70 of FIG.
The compressed digital video / audio data TD ′ corresponding to the one moving image mail transferred at a data transfer rate corresponding to the data transfer rate of the communication line 4 is input via the, and is supplied to the storage device 200. At this time, the CPU 500 in each client outputs a write command signal for instructing the communication speed write control unit 230 to write the compressed digital video / audio data TD ′ for the one moving image mail. The communication speed writing control unit 230 writes the compressed digital video / audio data TD ′ for one moving image mail at a data transfer speed corresponding to the data transfer speed of the communication line 4 based on the write command signal from the CPU 500. The write control signal TW is output to the storage device 200. Based on the write control signal TW, the storage device 200 operates so as to write the compressed digital video / audio data TD ′ for one moving image mail at a data transfer rate according to the data transfer rate of the communication line 4. As is clear from the above description, the communication speed writing control section 230 and the storage device 200 can realize the communication speed storage means 80 shown in FIG.

Next, the real-time read control unit 240
An embodiment of the real-time reading means 90 composed of the memory device 200 will be described with reference to FIG.

In FIG. 5, the compressed digital video / audio data TD 'for one moving picture mail is transferred to the communication speed storage means 80 composed of the communication speed writing control unit 230 and the storage device 200 on the communication line 4. After the data is written at the data transfer speed according to the speed, the CPU outputs a read command signal for instructing the real-time read control unit 240 to read the compressed digital video / audio data TD ′ for the one moving mail. . Based on the read command signal from the CPU 500, the real-time read control unit 240 outputs to the storage device 200 a read command signal RR for reading in real time the compressed digital video / audio data TD ′ for one moving image mail. The memory device 200 uses the read control signal RR.
Based on the above, the compressed digital video / audio data TD ′ for one moving image mail stored in the storage device 200 is read out in real time. Therefore, from the storage device 200, the compressed digital video / audio data CD ′ for one moving image mail is transmitted from the terminal 20 in real time.
2 and the real-time video as shown in Fig. 1
It is supplied to the voice expansion processing means 100. As is clear from the above description, the real-time read control unit 240 and the storage device 200 allow the real-time read means 90 to be used.
Can be realized.

[0046]

According to the present invention, when the data transfer rate of the communication line connecting each client is low and the moving picture mail cannot be transferred in real time between the clients, the moving picture mail cannot be transmitted or received. Also, the moving picture mail can be transferred between the clients according to the data transfer speed of the communication line, and the moving picture mail can be transmitted and received while maintaining the frame rate of the video signal and the continuity of the audio signal.

[0047]

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing an embodiment of a moving image mail system of the present invention.

FIG. 2 is a schematic diagram showing a data transfer state for explaining the operation of the moving picture mail system of FIG.

FIG. 3 is a schematic diagram showing a data transfer state for explaining the operation of the moving picture mail system of FIG.

FIG. 4 is a schematic diagram showing a data transfer state for explaining the operation of the moving image mail system of FIG.

FIG. 5 is a block diagram showing a specific example of a real-time storage means, a communication speed reading means, a communication speed storage means, and a real-time reading means.

[Explanation of symbols]

1 ... first client, 2 ... second client, 3
... communication data storage means, 4 ... communication line, 30 ... real-time video / audio input processing means, 40 ... real-time video / audio compression processing means, 50 ... real-time storage means, 6
0 ... Communication speed reading means, 70 ... Communication control means, 80
... communication speed writing means, 90 ... real-time reading means, 100 ... real-time video / audio expansion processing means,
110 ... Real-time video / audio output means.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical indication location H04N 7/14 8943-5C (72) Inventor Tomohisa Obiyama 292 Yoshida-cho, Totsuka-ku, Yokohama, Hitachi Factory Microelectronics Equipment Development Laboratory (72) Inventor Hiroyuki Sakai 292 Yoshida-cho, Totsuka-ku, Yokohama Hitachi Co., Ltd.Microelectronics Equipment Development Laboratory (72) Inventor Nakata 292 Yoshida-cho, Totsuka-ku, Yokohama Hitachi Factory Microelectronics Device Development Laboratory (72) Inventor Tetsuya Kawahara 292 Yoshida-cho, Totsuka-ku, Yokohama Hitachi Co., Ltd.Microelectronics Device Development Laboratory (72) Inventor Yuji Kimura 292 Yoshida-cho, Totsuka-ku, Yokohama Hitachi Ltd. Production (72) Inventor Norihiro Nakano 890 Kashimada, Sachiku-ku, Kawasaki Hitachi, Ltd. Information Systems Development Division, Hitachi Ltd.

Claims (4)

[Claims] 1. A moving image mail system for transmitting a moving image mail in a client / server system in which a plurality of clients and communication data storage means such as a file server are connected by a communication line, and the moving image mail to be transmitted to each client. Input processing means for capturing the video signal and audio signal in real time, compression processing means for compressing the captured video data and audio data in real time, and storing the compressed video data and compressed audio data compressed in real time. Storage means, storage means for storing the compressed video data and compressed audio data compressed in real time in the storage means in real time, and the compressed video data and compressed audio data stored in real time according to the transfer speed of the communication line. The memory hand And a communication control means for transmitting the compressed video data and the compressed audio data read from the storage means to the communication data storage means according to the transfer speed of the communication line. Mail system. 2. A moving picture mail system for receiving a moving picture mail in a client / server system in which a plurality of clients and communication data storage means such as a file server are connected by a communication line. In each of the clients, the communication data storage means is provided. Communication control means for receiving compressed video data and compressed audio data of the moving picture mail transferred according to the transfer speed of the communication line, storage means for accumulating the received compressed video data and compressed audio data, A storage unit that stores the received compressed video data and compressed audio data in the storage unit according to the transfer speed of the communication line, and the compressed video data and the compressed audio data that are stored according to the transfer speed of the communication line in real time. Reading means for reading from the storage means, and reading means for reading from the storage means And a decompression processing unit for decompressing the compressed video data and the compressed audio data in real time, and an output processing unit for outputting the decompressed video data and audio data in real time to the video display device and the audio reproduction device. Characteristic video mail system. 3. A moving picture mail system for transmitting and receiving moving picture mail in a client / server system in which a plurality of clients and communication data storage means such as a file server are connected by a communication line, and the moving picture mail to be transmitted to each client. Input processing means for capturing the video signal and audio signal in real time, compression processing means for compressing the captured video data and audio data in real time, and storing the compressed video data and compressed audio data compressed in real time. Storage means, storage means for storing the compressed video data and compressed audio data compressed in real time in the storage means in real time, and the compressed video data and compressed audio data stored in real time according to the transfer speed of the communication line. The memory Reading means for reading from the storage unit, transmitting compressed video data and compressed audio data read from the storage means to the communication data storage means according to the transfer speed of the communication line, and transferring from the communication data storage means to the communication line. A communication control unit that receives the compressed video data and the compressed audio data transferred according to the speed, a storage unit that stores the received compressed video data and the compressed audio data, and a communication control unit that stores the received compressed video data and the compressed audio data. Storage means for storing the storage means in the storage means in accordance with the transfer rate of the communication line; reading means for reading the compressed video data and compressed audio data stored in accordance with the transfer rate of the communication line in real time from the storage means; Decompression processing means for decompressing the compressed video data and compressed audio data read from the storage means in real time, Video mail system, characterized in that the video data and audio data extends the real-time video display device in real time, and an output processing means for outputting to the audio playback device. 4. The moving picture mail system according to claim 1, wherein the storage means has a capacity capable of storing the compressed video data and compressed audio data for at least one moving picture mail.