JPH10136017A - Data transfer system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data transfer system, where plural reception devices can receive multimedia data which a transmission device transmits at the desired resolution. SOLUTION: This data transmission device 101 inputs multimedia data and separates it at every medium. A data resolution conversion means 106 sequentially generates difference data to a maximum resolution from data of prescribed minimum resolution, difference data with data of second resolution and difference data with data of second and third resolutions, and transmits a multicast address (MA in the following), corresponding to respective data stored in an address corresponding table storage means 109. A data reception device 102 takes out MA, corresponding to reception resolution which a user desires from an address corresponding table storage means 117, designates it in a packet transmission/reception means 110, receives only the data of designated MA and reconstitutes multimedia data of desired resolution so as to output it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multimedia data stream transfer system for transferring a multimedia data stream through a network and outputting a multimedia data stream at a desired resolution at a plurality of terminals.

[0002]

2. Description of the Related Art As a conventional technique for distributing data at different resolutions to a plurality of terminals, an electronic conference system disclosed in Japanese Patent Application Laid-Open No. 7-327219 is known. FIG. 22 shows a configuration diagram of this electronic conference system. This electronic conference system includes a conference server 9001 connected to a network,
It is composed of a plurality of participant computers 9002, and each participant computer is a conference server 900.
The electronic material data is distributed to other participant computers via 1 and the participant computers receiving the electronic material data perform display at the respective display resolutions. First, in the participant computer 9002 serving as the sender, when distributing material data of the application 9009,
At 9010, the material data is converted to a vector format, and 9014
The communication control of 9015 transmits data to the network via the OS. Next, the conference server 9001 receives the communication control of 9008, passes it to the distribution destination management 9006 via the OS of 9007, creates the lowest resolution electronic material data of the distribution destination, and creates At 9003, a process for sequentially creating difference data for returning to digitized material data is performed, and at 9004, attributes such as material data or difference data and attributes such as display resolution are assigned, and data compression is performed at 9005. , 9007, the communication control 900 to the network
8 multicasts the material data and the difference data to all distribution destinations. Next, a participant computer 900 as a recipient
2, the communication control 9015 receives the material data and the difference data, passes it to the attribute determination 9013 via the OS of 9014, and determines that the data can be displayed by comparing it with its own display resolution at 9012. Stretched, 9011
To display.

[0003]

In the above-mentioned conventional data distribution technique, the conference server transfers all the low-resolution material data and difference data to the participant computers of all distribution destinations. Here, the conference server stores the display resolutions of all the participant computers in order to generate the material data and the difference data based on the display resolution of the destination participant computers. However, when the display resolution of the participant computer is changed or a new participant computer is added, there is no way to know these resolutions.

[0004] In addition, the distribution destination participant computer also obtains 9015 difference data having a resolution higher than its own display resolution.
Through the communication control of 9014, the processing is performed until the attribute is determined to be unnecessary in 9013 through the OS of 9014. When the distribution destination participant computer processes such unnecessary data, the CPU performance and the communication performance for other data processing are reduced.

[0005] Further, when a part of the data is lost when the digitized material data is multicast-transferred from the conference server, the receiving participant computer cannot display the digitized material data.

In order to solve these problems, the present invention relates to a data transfer system for transferring a multimedia data stream. First, a data transmission device transmits data in a format corresponding to an arbitrary reception resolution. The data receiving device does not process unnecessary data,
It is an object of the present invention to provide a data transfer system capable of efficiently receiving data of a desired resolution.

Second, the data transmitting apparatus can collect the receiving resolution of the data receiving apparatus, and can reduce the load on the network without sending unnecessary data to the network, thereby transferring data efficiently. It is an object of the present invention to provide a data transfer system that can perform the data transfer.

A third object of the present invention is to provide a data transfer system capable of complementing and outputting data when a part of the data is lost in a network.

Fourth, when a part of data is lost in the network, the missing data is retransmitted,
It is an object of the present invention to provide a data transfer system capable of performing highly reliable data transfer.

Fifth, when a part of data is lost in the network, the data is retransmitted only when the data is basic data having a low resolution, so that efficient, practical and reliable data transfer is possible. It is an object of the present invention to provide a data transfer system capable of performing the data transfer.

Sixth, a data transfer system capable of efficiently performing data transfer at a resolution suitable for the traffic condition of the network by changing the reception resolution in the data receiving apparatus in accordance with the rate of data loss in the network. The purpose is to provide.

[0012]

According to one aspect of the present invention, there is provided a data transfer system in which a data transmitting apparatus and a plurality of data receiving apparatuses are connected to a network. Is a data input unit, a data type identification unit, a data resolution conversion unit,
Transmission control means, wherein the data input means inputs data, the data type identification means identifies data inputted by the data input means for each medium, and the data resolution conversion means comprises: From the data identified by the type identification means for each medium, basic data that is the lowest resolution data among the predetermined resolution stages is generated, and the basic data and the second highest resolution second resolution data are generated. First difference data which is a difference from the data is generated, and a second difference data which is a difference between the second and third resolution data is generated.
Generate difference data, and sequentially generate and output difference data up to the highest resolution among the stages of the predetermined resolution, and the transmission control unit converts the basic data and the difference data output by the data resolution conversion unit into basic data and difference data. In addition to the attribute information, to transmit to the network, the data receiving device includes a reception control unit, a data reconfiguration unit, a data output unit, the reception control unit,
Receiving and outputting, from the network, data having attribute information of basic data and difference data for forming data of a desired resolution for each medium from the network; and the data reconstructing means outputs the basic data for each medium output by the data reception control means. From the data and the difference data, the data of the desired resolution is generated for each medium, and the data output unit outputs the data generated by the data reconstructing unit.
As a result, the data transmission device can transmit data in a format corresponding to any reception resolution, and the data reception device can efficiently receive data of a desired resolution without processing unnecessary data. A data transfer system that can be obtained.

According to a second aspect of the present invention, in the first aspect, the data transmitting apparatus further comprises transmission resolution determining means provided with a receiving resolution storage means, wherein the transmission resolution determining means uses a plurality of packet transmitting / receiving means to transmit a plurality of packets. A notification of the reception resolution for each medium is collected from the data reception device and stored in the reception resolution storage unit, and the highest resolution is determined as the transmission resolution for each medium, and the data reception device determines the reception resolution for each medium. A receiving resolution notifying unit for notifying the data transmitting device using a packet transmitting / receiving unit, whereby the data transmitting device can collect the receiving resolution of the data receiving device, and a network of unnecessary data can be collected. A data transfer system that can reduce the load on the network without sending data to It is.

According to a third aspect of the present invention, in the first aspect, the data reception control means of the data receiving apparatus further comprises a packet loss detecting means for detecting loss of a packet constituting the data stream, and the data reconstructing means comprises: Further comprising supplementary data generating means for generating complementary data of the lost packet detected by the packet loss detecting means, whereby the data is complemented and output when a part of the data is lost in the network. A data transfer system that can

Fourthly, the present invention is based on the first aspect, wherein the data transmission control means of the data transmission apparatus retransmits the packet when receiving the packet retransmission request, and stores the packet for retransmission. A packet loss detecting means for detecting a loss of a packet constituting the data stream; and a retransmission request for the lost packet detected by the packet loss detecting means. And a packet retransmission requesting means for performing a reliable data transfer by retransmitting the missing data when a part of the data is lost in the network. A transfer system is obtained.

According to a fifth and a fourth aspect of the present invention, in the fourth aspect, the packet retransmission requesting means of the data receiving apparatus includes a specific packet retransmission request for requesting a retransmission of a packet of a specific data stream that has been lost detected by the packet loss detecting means. Means that when data is partially lost in the network, data is retransmitted only if it is basic data with low resolution, resulting in efficient and practical reliability. A data transfer system capable of performing certain data transfer is obtained.

According to a sixth aspect of the present invention, in the first aspect, the data receiving apparatus further includes a packet loss detecting means in the data reception control means for detecting a loss of a packet constituting the data stream. A receiving resolution changing means for changing a receiving resolution in accordance with a state of packet loss detected by the detecting means, whereby the receiving resolution in the data receiving apparatus is changed in accordance with a rate of data loss in the network. Accordingly, a data transfer system capable of efficiently performing data transfer with a resolution suitable for a network traffic state is obtained.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.

(Embodiment 1) First, a first embodiment corresponding to claims 1 to 3 will be described. FIG.
FIG. 1 is a configuration diagram of a first embodiment of the present system. As shown in FIG. 1, in the present system, a data transmitting apparatus 101 and a plurality of data receiving apparatuses 102 are connected to a network 103.

The data transmitting apparatus 101 comprises a data input means 104, a data separating means 105, a data resolution converting means 106, a data transmission controlling means 107, a packet transmitting / receiving means 108, and an address correspondence table storage means 109. You.

The data receiving apparatus 102 includes a packet transmitting / receiving unit 110, a data reception control unit 111, a data reconstructing unit 112, a data combining unit 113, a data output unit 114, a reception resolution instruction unit 116, a reception address Storage means 115 and address correspondence table storage means 11
7 is comprised.

Here, the network is Ethernet, ATM
An exchange network or the like is used. As the packet transmitting / receiving means, means capable of performing multicast transfer such as IP multicast is used.

FIG. 2 shows an example of the types of resolutions handled by the present system. The video has three levels and the audio has two levels.

FIG. 3 is a diagram showing the transfer of a multimedia data stream by the present system. 1001 is a network, 1002 is a data transmitting device for transmitting a multimedia data stream, and 1003 and 1004 are data receiving devices for receiving a multimedia data stream. Reference numeral 1005 denotes an original multimedia data stream input to the data transmitting apparatus 1002, which is composed of two media of video and audio, and the video is composed of data blocks V1, V2, V3,.
And the audio data blocks A1, A2,.
・ ・ Is composed. 1006 is the data receiving device 100
3 is a multimedia data stream output;
The video has the same frame configuration as the original multimedia data stream 1005 and the resolution is
Regarding the resolution and the sound, each data block is obtained by converting the data block of the original sound into data having a double sampling period, and the resolution is the half sound first resolution. 1007 is the data receiving device 100
4 is a multimedia data stream output,
For the video, a second video having a frame rate that is half the original multimedia data stream 1005
Regarding the resolution and audio, the original multimedia data stream 1005 is composed of the same data blocks and has the same audio second resolution.

FIG. 4 is a diagram showing an example of data separation in the present system. The video is separated into a video basic data stream 1101, a video first difference data stream 1102, and a video second difference data stream 1103 to correspond to the three resolutions in FIG. Data stream 1101,
1101 and 1103 using the first video resolution, 110
1 and 1102, a video data stream having a video second resolution and a video third resolution using 1101 can be obtained. The audio is separated into an audio basic data stream 1104 and an audio first difference data stream 1105 to support the two resolutions in FIG. 1104, 1
Each data block 105 is obtained by converting the audio data block of the original 1005 into data having a double sampling period, and the sampling timing is shifted by a half period. Using the data streams 1104 and 1105, an audio data stream having the first audio resolution and the second audio resolution using the 1104 can be obtained.

The data transmitting apparatus of the present system packetizes a basic data stream and a differential data stream generated from an original multimedia data stream, and transmits the packets to a network using a different multicast address for each data stream.

FIG. 5 is an example of a multicast address correspondence table. Five multicast addresses corresponding to five types of data streams are defined.

In FIG. 3, data receiving apparatus 1003
Receives the packets addressed to the four multicast addresses indicated by 1008, generates the video basic, video first difference, video second difference, and audio basic data streams,
A multimedia data stream having a resolution and a first audio resolution is output. The data receiving device 1004 receives the packets addressed to the four multicast addresses indicated by 1009, generates a video basic, video first difference, audio basic, and audio first difference data streams, and outputs the video second resolution and the audio second resolution. Output a data stream.

Next, the detailed operation of the present system will be described using an example. First, the operation of the data transmission device 101 will be described. The data input unit 104 receives an input of a multimedia data stream. The multimedia data stream is continuous data such as 1005 in FIG.

Next, the data separating means 105 receives the multimedia data stream from the data input means 104 and outputs a data stream for each medium.

FIG. 6 shows an example of separation of a data stream for each medium. 1301 is the same as the multimedia data stream 1005 in FIG. 4 and separates 1301 into two data streams 1302 and 1303. 130
2 is a video media data stream, 1303 is
It is a data stream of audio media.

Next, the data resolution conversion means 106 receives the data stream for each medium from the data separation means 105 and separates the data stream into a basic data stream and a difference data stream. For example, the video media data stream 1302 of FIG.
1, the video first difference data stream 1102, and the video second difference data stream 1103, and the audio media data stream 1303 in FIG. 6 is converted into the audio basic data stream 1104 and the audio first difference data stream 1105 in FIG. To separate. Further, each separated data stream is output for each data block.

FIG. 8 shows an example of a data block message, which is composed of the following four parts. 1601: Data type. Coded data stream type. 1602: Serial number of the data block for each data stream 1603: Data length of the data body 1604: Data body (one data block) In this example, the type of the data stream is “video first differential data stream” and the data block Is the second data block of the data stream, the data length is 4096, and the data is the content of the data block V7.

Next, the data transmission control means 107 receives the data block message from the data resolution conversion means 106 and divides it into a plurality of packets.

FIG. 9 shows an example of a packet generated by the data transmission control means 107, which is composed of the following six parts. 1701: Source address (own address) 1702: Data type. Coded type of data stream 1703: Serial number of data block for each data stream 1704: Packet number / total number of packets in data block 1705: Data length of data body 1706: Data body (divided data block) The packet of this example has a source address of ss. ss. s
s. 01 and the data stream type is “video first
Differential data stream ", wherein the data blocks are:
The second data block of the data stream,
This is the first packet of the data block divided into four, the data length is 1024, and the data body is the first content of the data block V7 divided into four. Next, the multicast address for transmitting the data stream is stored in the address correspondence table storage means 109.
It instructs the packet transmitting means 108 to output the generated packet as a message and transmit it to the multicast address. Here, the address correspondence table storage means 109 stores a multicast address correspondence table as shown in FIG. 5, and can extract a basic address for each medium and a multicast address corresponding to each differential data stream. According to the example of FIG.
Since the packet in FIG. 9 is the video first difference data stream, xx. xx. xx. Send to 11.

Next, the packet transmission / reception means 108 generates a packet from the message received from the data transmission control means 107, and sends the packet to the network 103 to the designated address. FIG.
08 is an example of a packet generated, and is composed of the following four parts. 1801: destination address 1802: source address 1803: data length 1804: data body In the packet for transmitting the packet in FIG. 9, the destination address 1801 is xx. xx. xx. 11, the source address 1802 is ss. ss. ss. 01, data length 1803
Is the length of the data body 1804, and the data body 1804 includes the entire message of FIG.

The operations of the data input unit 104, the data separation unit 105, the data resolution conversion unit 106, the data transmission control unit 107, and the packet transmission / reception unit 108 are performed in parallel, and the multimedia data stream is input continuously. , So that packets can be transmitted to the network 103.

Next, the operation of the data receiving apparatus 102 will be described. First, the receiving resolution instructing means 116 receives a receiving resolution which is a resolution that the receiving user wants to receive. As shown in FIG. 7, it is assumed that the user has input the resolution of the video at the second resolution and the audio has the resolution of the first audio. Next, a multicast address corresponding to the data stream constituting the multimedia data stream of the reception resolution is obtained from the address correspondence table storage means 117, and a reception address list is created. The address correspondence table storage means 117 stores the same address correspondence table as the address correspondence table storage means 109 of the data transmitting apparatus 101. FIG. 11 shows an example of the created reception address list, which corresponds to the example of the user resolution in FIG. That is, the data stream having the resolution (the second video resolution and the first audio resolution) shown in FIG.
01, a video first differential data stream 1102, and an audio basic data stream 1104. According to FIG.
It becomes three addresses of 1. The reception address list created in this way is passed to the packet transmission / reception means 110.
Further, the data reception control unit 111, the data reconfiguration unit 1
12. The receiving resolution is passed to the data combining means 113.

Next, the packet transmission / reception means 110 receives the reception address list from the reception resolution instructing means 116, stores it in the reception address storage means 115, and selects a packet having the address described therein as the transmission destination address from the network 103. To receive. Figure 1 shows the received packet.
0 format. From such a packet, the data body 1
804 is extracted, and a message in the format of FIG. 9 is generated.

Next, the data reception control means 111 receives the message in the format of FIG. 9 from the packet transmission / reception means 110, and receives a data type 170 indicating the type of the data stream.
2, data block number 1703, packet number 170
4 to form a data block in the data stream and output it as a message in the format of FIG.

Next, the data reconstructing means 112 receives the data block from the data reception control means 111 by a message in the format of FIG. 8, reconstructs the data block according to the data type 1601 and the data block number 1602, A data stream for each medium such as 1302 or an audio media data stream 1303 is generated at a specified resolution.

Next, the data combining means 113 receives the data streams for each medium from the data reconstructing means 112 and combines them to generate a multimedia stream having a designated resolution.

Next, the data output means 114 outputs the multimedia data stream generated by the data combining means 113 to a decoder or a storage device. As a decoder,
Some are realized only by software, and some are hardware and driver software.

The operations of the packet transmitting / receiving means 110, the data reception control means 111, the data reconstructing means 112, the data combining means 113, and the data output means 114 are performed in parallel. The data stream is configured to be continuously output.

The multimedia data stream may be composed of a plurality of videos and audios, and may be composed of texts, images, display positions / display timings of respective media, etc. in addition to the audios and videos. Is also good. Also, in the present embodiment, the resolution of the video is set in three levels,
Although the audio resolution is set to two levels, it may be set to any level.

In this embodiment, the means (hardware / software) for decoding, that is, reproducing data is a multimedia data stream such as W
An example has been described in which the data combining means is required on the assumption that only the data format including moving images and audio is accepted, such as the standard AVI data format of Windows, In the case where the data is separately provided by voice, it is not necessary to combine the data into a multimedia data stream irrespective of the input data on the data transmitting apparatus side, and thus the data combining means is not necessarily required.

As described above, in this embodiment, the data transmitting apparatus divides the multimedia data stream, performs resolution conversion, and generates difference data, sends the data to individual multicast addresses, and specifies the data receiving apparatus. Receiving the packet of the multicast address corresponding to the received resolution, and reconstructing and outputting the multimedia data stream, the data transmitting apparatus can transmit data in a format corresponding to an arbitrary receiving resolution. The data receiving apparatus can efficiently output data of a desired resolution without processing unnecessary data, and the practical effect is large.

(Embodiment 2) Next, a second embodiment of the present invention will be described. FIG. 12 is a configuration diagram of Embodiment 2 of the present system. As shown in FIG. 12, in the present system, a data transmitting apparatus 101 and a plurality of data receiving apparatuses 102 are connected to a network 103.

The data transmission device 101 includes a data input unit 104, a data separation unit 105, a data resolution conversion unit 106, a data transmission control unit 107, a packet transmission / reception unit 108, and an address correspondence table storage unit 109.
, Transmission resolution determination means 2001 and reception resolution storage means 2002.

The data receiving apparatus 102 includes a packet transmitting / receiving means 110, a data receiving control means 111, a data reconstructing means 112, a data combining means 113, a data output means 114, a receiving resolution instructing means 116, a receiving address Storage means 115 and address correspondence table storage means 11
7 and a receiving resolution notifying means 2003.

Next, the operation of the present system will be described.
First, the data transmission device 101 will be described. The packet transmission / reception means 108 is connected to the network 103 as shown in FIG.
Is received, and if the data body 1804 is a reception resolution notification message, it is output to the transmission resolution determination unit 2001.

FIG. 13 shows an example of the reception resolution notification message, which is composed of the following three parts. 2101: Source address 2102: Type code ("Reception resolution notification message"
2103: Reception resolution In this example, the source address is ss. ss. ss. 0
2. The type code is a code indicating the “reception resolution notification message”, and the content is “video transmission resolution = video second resolution, audio transmission resolution = audio first resolution”.

Upon receiving the reception resolution notification message from the packet transmission / reception means 108, the transmission resolution determination means 2001 stores it in the reception resolution storage means 2002.

FIG. 14 shows an example of the reception resolution table stored in the reception resolution storage means 2002. For each data receiving apparatus 102, the address and the latest reception resolution are set to 1
As one record. Here, ss. s
s. ss. 08 indicates that no audio media data has been received. Also, ss. ss. ss. 16 indicates that reception of all data has been stopped, and this record may be deleted. Transmission resolution determining means 2001
Selects the highest resolution for each medium from the reception resolutions stored in the reception resolution storage unit 2002 and determines the highest resolution as the transmission resolution. In the example of FIG. 14, the video second resolution and the audio second resolution are the transmission resolutions.

The data separation means 105, the data resolution conversion means 106, and the data transmission means 107 are provided for the transmission resolution determination means 2 based on the input multimedia data stream.
001 generates a data stream packet corresponding to the determined transmission resolution. At the transmission resolutions (video second resolution, audio second resolution) determined based on the example of FIG. 14, four data streams of video basic, video first difference, audio basic, and audio first difference are generated.

In addition, the operation of the data transmitting apparatus 101 is as follows.
The operation is the same as that of the first embodiment. Next, the operation of the data receiving apparatus 102 will be described.

The receiving resolution instruction means 116 is used in the first embodiment.
In addition to the above operation, the receiving resolution notified from the user is passed to the receiving resolution notifying means 2003. The receiving resolution notifying means 2003 notifies the data transmitting apparatus 101 of the receiving resolution received from the receiving resolution instructing means 116 as a receiving resolution notifying message using the packet transmitting / receiving means 110. Further, when data reception is stopped due to an instruction of the receiving side user or an abnormality in the data receiving apparatus 102, the data transmission apparatus 101 is notified of the reception stop by a reception resolution notification message.

In addition, the operation of the data transmitting apparatus 102 is as follows.
The operation is the same as that of the first embodiment. Note that the receiving resolution notifying unit 2003 periodically sends out the receiving resolution notifying message, and the transmitting resolution determining unit 2001 checks that the data receiving device 10 has no periodic notification of the receiving resolution notifying message.
2 may determine that data has not been received.

As described above, in the present embodiment, the data transmitting apparatus includes the transmission resolution determining means including the receiving resolution storing means, and the data receiving apparatus determines the receiving resolution for each medium by using the packet transmitting / receiving means. By providing the receiving resolution notifying means for notifying the data transmitting apparatus, the data transmitting apparatus can collect the receiving resolution of the data receiving apparatus, and can reduce the load on the network without sending unnecessary data to the network. The data can be efficiently transferred, and the practical effect is great.

(Embodiment 3) Next, a third embodiment corresponding to claims 5 and 6 will be described. FIG.
Is a configuration diagram of a third embodiment of the present system. FIG.
As shown in the figure, in this system, a data transmitting apparatus 101 and a plurality of data receiving apparatuses 102 are connected to a network 103.

The data transmitting apparatus 101 comprises a data input unit 104, a data separating unit 105, a data resolution converting unit 106, a data transmission controlling unit 107, a packet transmitting / receiving unit 108, and an address correspondence table storing unit 109. You.

The data receiving device 102 includes a packet transmitting / receiving means 110, a data reception control means 111, a data reconstructing means 112, a data combining means 113, a data output means 114, a reception resolution instructing means 116, a reception address Storage means 115 and address correspondence table storage means 11
7; a packet loss detection unit 3001; and a supplementary data generation unit 3002.

Next, the operation of the present system will be described.
The operation of data transmitting apparatus 101 is the same as in the first embodiment.

The operation of data receiving apparatus 102 is different from that of the first embodiment in the operations of data reception control means 111 and data reconstruction means 112.

Data reception control means 111 detects packet loss using packet loss detection means 3001 in addition to the operation of the first embodiment. The detection of packet loss is described as "If a packet of the latter number arrives earlier than the arrival of a certain packet, and if the packet does not arrive after a certain period of time, it is assumed that the packet has been lost." Perform according to conditions. When the packet is lost, the data reconfiguration unit 112 is notified that the data block message could not be generated.

The data reconstructing means 112 is used in the first embodiment.
In addition to the above operation, when a notification of packet loss is received from the data reception control unit 111, the supplementary data generation unit 3
002, the complementary data is created, and a data stream for each medium is generated using the complementary data.

The supplementary data generation means 3002 creates supplementary data capable of filling in missing portions of the data stream. The complementary data can be any data as long as it is in the correct format of the data stream.
Data such as blank paper for video and silence for audio may be used. However, it is desirable to generate complementary data that will result in a data stream with less discomfort when reproduced. For example, with respect to video data, the supplementary data generation means 3002 further includes a means for storing the immediately preceding data block, so that the immediately preceding frame can be output as supplementary data. Further, if the format of the video data or the means for expanding and displaying the output video data allows the use of a special block meaning "no change from the immediately preceding frame", it can be used as supplementary data.

As described above, in the present embodiment, the data reception control means of the data receiving apparatus has the packet loss detecting means, and the data restructuring means has the complementary data generating means. In this case, data can be complemented and output, and the practical effect is great.

(Embodiment 4) Next, a fourth embodiment of the present invention will be described. FIG. 16 is a configuration diagram of Embodiment 4 of the present system. As shown in FIG. 16, in the present system, a data transmitting apparatus 101 and a plurality of data receiving apparatuses 102 are connected to a network 103.

The data transmission device 101 includes a data input unit 104, a data separation unit 105, a data resolution conversion unit 106, a data transmission control unit 107, a packet transmission / reception unit 108, and an address correspondence table storage unit 109
, A packet retransmission unit 4001 and a retransmission packet storage unit 4002.

The data receiving apparatus 102 includes a packet transmitting / receiving means 110, a data receiving control means 111, a data reconstructing means 112, a data combining means 113, a data output means 114, a receiving resolution instructing means 116, a receiving address Storage means 115 and address correspondence table storage means 11
7, packet loss detection means 3001, and packet retransmission request means 4003.

Next, the operation of the present system will be described.
First, the operation of the data transmission device 101 will be described.
The data transmission control unit 107 operates as described in the first embodiment, and further includes the operations of the packet retransmission unit 4001 and the retransmission packet storage unit 4002. When receiving a packet retransmission request from the data receiving apparatus 102, the packet retransmission unit 4001 retrieves and retransmits the packet specified by the packet retransmission request from the retransmission packet storage unit 4002. At this time, the transmission destination is the address of the data receiving apparatus 102 that has transmitted the packet retransmission request, or
When a packet retransmission request is received from a plurality of data receiving devices 102, a multicast address corresponding to the data stream of the packet is received. In particular, the latter method using the multicast address is preferable because it reduces network traffic. Retransmission packet storage means 400
Reference numeral 2 stores the packets generated by the data transmission control means 107 in preparation for retransmission of the packets, within a range such as a period or a limit.

FIG. 17 shows an example of a packet retransmission request message, which is composed of the following five parts. 4101: Source address (address of data receiving device) 4102: Data type. Indicates a packet retransmission request 4103: Retransmission data type. Type of data stream to be retransmitted 4104: Serial number of data block for each data stream 4105: Serial number of packet number in data block In this example, a request for retransmission of the packet in FIG. 9 is made.

The packet transmitting / receiving means 108 receives a packet in the format of FIG. 10 from the network 103, and outputs the data to the data transmission control means 107 if the data body 1804 is in the format of the packet retransmission request message in FIG.

In addition, the operation of the data transmitting apparatus 101 is as follows.
The operation is the same as that of the first embodiment. Next, the operation of the data receiving apparatus 102 will be described. The data reception control means 111 operates in the same manner as in the first embodiment, and the packet loss detection means 3001 operates in the same manner as in the third embodiment. I do. The packet retransmission request is transmitted by transmitting a packet retransmission request message as shown in FIG.
01. Note that if a packet is not retransmitted after a certain period of time has passed since the packet retransmission request was made, a packet retransmission request may be further made. Also,
The number of times of making a packet retransmission request may be limited. As described above, the packet which has not arrived even when the packet retransmission request is issued is notified to the data reconfiguration unit 112 as having been lost.

The data reconstructing means 112 is used in the first embodiment.
In addition to the same operation as described above, when a notification of packet loss is received from the data reception control unit 111, for example, the entire frame data including the lost packet is deleted in the video media, or the supplementary data as in the third embodiment is used. If it has a generating means, it generates complementary data and generates a usable data stream.

The operation of the data receiving apparatus 102 is as follows.
The operation is the same as that of the first embodiment. As described above, in the present embodiment, the data transmission control unit of the data transmission device includes the packet retransmission unit and the retransmission packet storage unit, and the data reception control unit of the data reception device includes the packet loss detection unit and the packet retransmission request unit. Is provided, when the packet is lost in the network, the lost data is retransmitted, so that highly reliable data transfer can be performed, and the practical effect is large.

(Embodiment 5) Next, a fifth embodiment of the present invention will be described. FIG. 18 is a configuration diagram of a fifth embodiment of the present system. As shown in FIG. 18, in the present system, a data transmitting apparatus 101 and a plurality of data receiving apparatuses 102 are connected to a network 103.

The data transmission device 101 includes a data input unit 104, a data separation unit 105, a data resolution conversion unit 106, a data transmission control unit 107, a packet transmission / reception unit 108, and an address correspondence table storage unit 109
, A packet retransmission unit 4001 and a retransmission packet storage unit 4002.

The data receiving apparatus 102 includes a packet transmission / reception unit 110, a data reception control unit 111, a data reconfiguration unit 112, a data combination unit 113, a data output unit 114, a reception resolution instruction unit 116, a reception address Storage means 115 and address correspondence table storage means 11
7, a packet loss detection unit 3001 and a specific packet retransmission request unit 5001.

Next, the operation of the present system will be described.
First, the operation of the data transmitting apparatus 101 is the same as that of the fourth embodiment. Next, the operation of the data receiving apparatus 102 will be described.

Data reception control means 111 is used in the fourth embodiment.
The packet retransmission request unit 4003 is replaced with a specific packet retransmission request unit 5001. When the packet loss detection unit 3001 detects the packet loss, the packet retransmission request unit Requesting means 5001 makes a packet retransmission request. For example, when the video media is received up to the third video resolution, the specific data stream is the video basic data stream 1101 in FIG. Alternatively, there are two video basic data streams 1101 and a video first difference data stream 1102. In this way, correct frame data can be obtained at regular intervals, and data of practical quality can be obtained. Furthermore, in addition to the present embodiment, when data complementation is performed as in the third embodiment, there is a correct data frame at regular intervals, compared to a case where retransmission is not performed at all. Data completion can be performed. Also, compared to the case where packet retransmission is performed for all data streams, the number of packet retransmission request messages and retransmitted packets is smaller, and an increase in network traffic can be reduced.

FIG. 19 shows an example of a reception resolution and a specific data stream to be retransmitted. As in this example, a specific data stream for which a retransmission request is made is determined according to the reception resolution for each medium. In addition, the data receiving device 102
Is similar to that of the fourth embodiment.

As described above, according to the present embodiment, the data transmission control means of the data transmission apparatus includes the packet retransmission means,
When the packet is lost in the network, the data is basic data having a low resolution by providing a retransmission packet storage unit and the data reception control unit of the data receiving apparatus including a packet loss detection unit and a specific packet retransmission request unit. By retransmitting the data only to the data, efficient and practical reliable data transfer can be performed, and the practical effect is large.

(Embodiment 6) Next, a sixth embodiment of the present invention will be described. FIG. 20 is a configuration diagram of Embodiment 6 of the present system. As shown in FIG. 20, in this system, a data transmitting apparatus 101 and a plurality of data receiving apparatuses 102 are connected to a network 103.

The data transmitting apparatus 101 comprises a data inputting unit 104, a data separating unit 105, a data resolution converting unit 106, a data transmitting control unit 107, a packet transmitting / receiving unit 108, and an address correspondence table storing unit 109. You.

The data receiving apparatus 102 includes a packet transmitting / receiving means 110, a data reception control means 111, a data reconstructing means 112, a data combining means 113, a data output means 114, a reception resolution instructing means 116, a receiving address Storage means 115 and address correspondence table storage means 11
7, a packet loss detecting unit 3001, and a receiving resolution changing unit 6001.

Next, the operation of the present system will be described.
First, the operation of the data transmitting apparatus 101 is the same as in the first embodiment. Next, the operation of the data receiving apparatus 102 will be described.

Receiving resolution changing means 6001 calculates the packet loss rate based on the detection of packet loss by packet loss detecting means 3001, and newly determines the receiving resolution based on the calculation result.

FIG. 21 shows an example of changing the reception resolution of a video medium. For example, if the condition 6105 that the packet loss rate exceeds 3% is satisfied in the state 6103 in which the video third resolution is received, the state shifts to the state 6102 in which the video second resolution is received. Here, the packet loss rate is 1%
If the condition 6107 of less than is satisfied, the above state 6103 is satisfied.
Condition 610 that it can return to
If 4 is satisfied, the flow shifts to a state 6101 for receiving the first video resolution. However, the state does not shift to a state in which the receiving user receives a resolution higher than the receiving resolution input to the receiving resolution instructing means 116.

The receiving resolution instructing means 116 performs the same operation as in the first embodiment according to the receiving resolution determined by the receiving resolution changing means 6001.

In addition, the operation of the data receiving apparatus 102 is as follows.
This is the same as in the first embodiment. In the data receiving apparatus 102, by lowering the reception resolution by the reception resolution changing unit 6001, the load of the multimedia stream data reception processing is reduced, and more processing performance can be allocated to other processing. Further, when notifying the data transmitting apparatus 101 of the changed reception resolution as in the second embodiment, the amount of data transmitted to the network is reduced.

Note that the receiving resolution that can be changed by the receiving resolution changing means 6001 may be limited by the receiving user or the like, or the changed receiving resolution may be notified to the receiving user.

As described above, according to the present embodiment, the data receiving apparatus includes the packet loss detecting means in the data receiving control means and the reception resolution changing means, so that the rate of packet loss in the network is reduced. , The data transfer can be efficiently performed at a resolution suitable for the traffic condition of the network, and the practical effect is large.

In the first to sixth embodiments, when the configurations of a plurality of receiving apparatuses are all the same, for example, the transmitting side has no retransmitting means and the receiving side has no retransmitting request means. The transmitting side has retransmitting means. , The receiving side is provided with retransmission request means, etc., but as in the invention according to claim 10,
A configuration in which a plurality of receiving apparatuses have different configurations, for example, a transmitting apparatus having retransmission means, at least one receiving apparatus having no retransmission request means, and at least one receiving apparatus having retransmission request means, It goes without saying that it can be considered as various combinations.

[0096]

As described above, according to the first aspect, the data transmitting apparatus can transmit data in a format corresponding to an arbitrary receiving resolution, and the data receiving apparatus processes unnecessary data. Thus, it is possible to provide a data transfer system capable of efficiently outputting data having a desired resolution.

According to the second aspect of the present invention, the data transmission device can collect the reception resolution of the data reception device, and unnecessary data is not sent to the network, so that the load on the network can be reduced. A data transfer system capable of transferring data can be provided.

According to the third aspect of the invention, it is possible to provide a data transfer system capable of complementing and outputting data when part of the data is lost in the network.

According to the fourth invention, there is provided a data transfer system capable of performing highly reliable data transfer by retransmitting the missing data when a part of the data is lost in the network. Can be.

According to the fifth aspect, when a part of the data is lost in the network, the data is retransmitted only when the data is basic data having a low resolution. A data transfer system capable of performing certain data transfer can be provided.

According to the sixth aspect, by changing the receiving resolution in the data receiving apparatus in accordance with the rate of data loss in the network, data can be efficiently transferred at a resolution suitable for the traffic state of the network. And a data transfer system capable of providing the same.

[Brief description of the drawings]

FIG. 1 is a configuration diagram according to a first embodiment of the present invention.

FIG. 2 is an example diagram of types of resolution.

FIG. 3 is an example diagram of transfer of a multimedia data stream.

FIG. 4 is an example diagram of data separation.

FIG. 5 is an example diagram of a multicast address correspondence table;

FIG. 6 is an example diagram of a data stream for each medium.

FIG. 7 shows an example of a user reception resolution.

FIG. 8 is an example diagram of a data block message.

FIG. 9 is an example of a packet generated by the data transmission control means.

FIG. 10 is an example diagram of a packet transmitted to a network.

FIG. 11 is an example of a reception address list.

FIG. 12 is a configuration diagram according to a second embodiment of the present invention.

FIG. 13 is an example diagram of a reception resolution notification message.

FIG. 14 is an example diagram of a required resolution list.

FIG. 15 is a configuration diagram according to a third embodiment of the present invention.

FIG. 16 is a configuration diagram according to a fourth embodiment of the present invention.

FIG. 17 shows an example of a packet generated by the data transmission control means.

FIG. 18 is a configuration diagram according to a fifth embodiment of the present invention.

FIG. 19 is an example diagram of a reception resolution and a specific data stream to be retransmitted;

FIG. 20 is a configuration diagram according to a sixth embodiment of the present invention.

FIG. 21 is a diagram illustrating an example of changing the reception resolution of a video medium.

FIG. 22 is a configuration diagram of a conventional electronic conference system.

[Explanation of symbols]

 Reference Signs List 101 data transmission device 102 data reception device 103 network 104 data input means 105 data separation means 106 data resolution conversion means 107 data transmission control means 108 packet transmission / reception means 109 address correspondence table storage means 110 packet transmission / reception means 111 data reception control means 112 data retransmission Configuration means 113 Data combining means 114 Data output means 115 Receive address storage means 1001 Network 1002 Data transmitter 1003 Data receiver 1004 Data receiver 1005 Multimedia data stream 1006 Multimedia data stream 1007 Multimedia data stream 1008 Receive address 1009 Receive address 1101 Video basic data stream 1102 Video first difference data Stream 1103 Video second differential data stream 1104 Audio basic data stream 1105 Audio first differential data stream 1301 Multimedia data stream 1302 Video media data stream 1303 Audio media data stream 1601 Data type 1602 Data block number 1603 Data length 1604 Data body 1701 Transmission Original address 1702 Data type 1703 Data block number 1704 Packet number 1705 Data length 1706 Data body 1801 Destination address 1802 Source address 1803 Data length 1804 Data body 2001 Transmission resolution determination means 2002 Reception resolution storage means 2003 Reception resolution notification means 2101 Transmission source Address 2102 Data type 2103 Reception Visibility 3001 Packet loss detection means 3002 Complementary data generation means 4001 Packet retransmission means 4002 Retransmission packet storage means 4003 Packet retransmission request means 4101 Source address 4102 Data type 4103 Retransmission data type 4104 Data block number 4105 Packet number 5001 Specific packet retransmission request means 6001 reception resolution changing means 9001 conference server 9002 participant computer 9003 image development / difference data generation 9004 attribute addition 9005 compression 9006 distribution destination management 9007 OS 9008 communication control 9009 application 9010 vector format 9011 display 9012 expansion 9013 attribute judgment 9014 OS 9015 communication control

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yutetsu Kansuke 1006 Kadoma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Kato et al. (72) Inventor Shugo Horigami 1006 Kadoma, Kazuma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Tsutomu Uenoyama 1006, Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (10)

[Claims] 1. A data transfer system in which a data transmission device and a plurality of data reception devices are connected to a network, the data transmission device comprising: a data input unit; a data type identification unit; a data resolution conversion unit; Control means, wherein the data input means inputs data, the data type identification means identifies data input by the data input means for each medium, and the data resolution conversion means comprises: From the data identified for each medium by the identification means, the lowest one of the predetermined resolution stages is selected.
Generating first difference data which is a difference between the basic data and the next higher resolution second resolution data, and generating second and third resolution data; , And sequentially generates and outputs difference data up to the highest resolution among the predetermined resolution stages, and the transmission control means outputs the data resolution conversion means. The basic data and the differential data are added to attribute information that indicates that they are the basic data and the respective differential data, and are transmitted to the network. The data receiving device includes: a reception control unit; And a data output unit, wherein the reception control unit is configured to provide basic and differential data for configuring data of a desired resolution for each medium from the network. Receiving and outputting data having attribute information of
The data having the desired resolution is generated for each medium from the basic data and difference data for each medium output by the data reception control means, and the data output means outputs the data generated by the data reconstructing means. A data transfer system, wherein data is input to the data transmission device, transferred through the network, and each of the data reception devices outputs data having a desired resolution. 2. A data transfer system in which a data transmission device and a plurality of data reception devices are connected to a network, the data transmission device comprising: a data input unit; an address correspondence table storage unit; a data separation unit; Resolution conversion means, data transmission control means, and packet transmission / reception means, wherein the data input means receives a multimedia data stream, and the data separation means receives the multimedia data stream inputted by the data input means Into a data stream for each medium, and the data resolution conversion means converts the data stream separated for each medium by the data separation means into a data stream having the lowest resolution among the predetermined resolution stages. Generate a basic data stream, and A first difference data stream which is a difference between the second resolution data stream having a high resolution and a second difference data stream which is a difference between the second and third resolution data streams is generated. Generating and outputting a differential data stream up to the highest resolution among the predetermined resolution stages, wherein the address correspondence table storage means stores a basic data stream for each medium and a transmission multicast address corresponding to each differential data stream. The data transmission control unit divides the data stream output by the data resolution conversion unit, obtains a corresponding destination multicast address from the address correspondence table storage unit and packetizes the data stream. Packet transmission and network address Wherein the data receiving apparatus includes an address correspondence table storage unit, a packet transmission / reception unit having a reception address storage unit, a reception resolution instruction unit, a data reception control unit, and a data reconfiguration unit. And a data output unit. The address correspondence table storage unit stores a basic address for each medium and a multicast address corresponding to each differential data stream. Inputting a desired reception resolution to the packet, obtaining a plurality of multicast addresses corresponding to basic and differential data streams constituting the data of the desired reception resolution from the address correspondence table storage means, and providing the multicast addresses to the packet transmission / reception means, The transmission / reception means includes a plurality of multi-channels designated by the reception resolution designating means. Storing a cast address in the reception address storage means, transmitting a packet to a network, and receiving a packet from the network to the own address and to a plurality of multicast addresses stored in the reception address storage means; Means for generating and outputting, from the packet received by the packet transmitting / receiving means, basic and differential data streams constituting the data of the desired reception resolution for each medium, the data reconstructing means comprising: the data reception control means Generates a data stream of the desired resolution for each medium from the basic data stream and the difference data stream for each medium output by the device, and the data output unit outputs the multimedia data stream generated by the data reconstructing unit The said A data transfer system, wherein a multimedia data stream is input to a data transmitting device and transferred through the network, and each of the data receiving devices outputs a multimedia data stream having a desired resolution. 3. A data transfer system in which a data transmission device and a plurality of data reception devices are connected to a network, wherein the data transmission device includes a data input unit, an address correspondence table storage unit, a data resolution conversion unit, Data transmission control means, comprising a packet transmission and reception means, wherein the data input means inputs a plurality of data streams, the data resolution conversion means, from each of the plurality of data streams input by the data input means, A basic data stream which is a data stream having the lowest resolution among the predetermined resolution steps is generated, and a first data stream which is a difference between the basic data stream and a data stream having the second highest resolution is generated. A difference data stream is generated, and a difference data stream having a difference between the second and third resolution data streams is generated. Generating a differential data stream, and sequentially generating and outputting a differential data stream up to the highest resolution among the predetermined resolution stages. The address correspondence table storage means stores a basic data stream for each medium and each differential data stream. Storing a transmission multicast address corresponding to the stream;
The data stream output by the data resolution conversion unit is divided, a corresponding destination multicast address is obtained from the address correspondence table storage unit and packetized, and the packet transmission / reception unit transmits a packet to the network and sends the packet to the network automatically. The data reception device receives a packet addressed to an address. The data reception device includes: an address correspondence table storage unit; a packet transmission / reception unit having a reception address storage unit; a reception resolution instruction unit; a data reception control unit; Comprising a configuration unit and a data output unit, wherein the address correspondence table storage unit stores a basic address for each medium and a multicast address corresponding to each differential data stream. Enter the desired receiving resolution for each medium and enter the desired receiving resolution. A plurality of multicast addresses corresponding to the basic and differential data streams constituting the data of the transmission resolution are obtained from the address correspondence table storage means and given to the packet transmission / reception means, and the packet transmission / reception means is instructed by the reception resolution instruction means. Storing the plurality of multicast addresses in the reception address storage means, transmitting a packet to the network, and receiving packets addressed to the own address from the network and to the plurality of multicast addresses stored in the reception address storage means, The data reception control means generates and outputs, from the packet received by the packet transmission / reception means, a basic data and a differential data stream constituting data of the desired reception resolution for each medium, and outputs the data. Reception control means Generating a data stream of the desired resolution for each medium from a basic data stream and a differential data stream for each medium to be output, and the data output means for outputting the multimedia data stream generated by the data reconstructing means A data transfer system, comprising: inputting a plurality of data streams to the data transmitting device, transferring the plurality of data streams through the network, and each of the data receiving devices outputting a multimedia data stream having a desired resolution. 4. The data transmitting apparatus further comprises a transmission resolution determining means having a receiving resolution storing means, wherein the transmitting resolution determining means uses a packet transmitting / receiving means to determine a receiving resolution of each medium from a plurality of data receiving apparatuses. The notification is collected and stored in the reception resolution storage means, and the highest resolution for each medium is determined as the transmission resolution. The data reception apparatus determines the reception resolution for each medium by using the packet transmission / reception means. 3. The apparatus according to claim 2, further comprising: a receiving resolution notifying unit for notifying the receiving device.
Or the data transfer system according to claim 3. 5. The data transfer system according to claim 2, wherein the data reception control means of the data reception device has a packet loss detection means for detecting loss of a packet constituting the data stream. . 6. The data reconstructing means of the data receiving device,
6. The data transfer system according to claim 5, further comprising complementary data generation means for generating complementary data of the lost packet detected by the packet loss detection means. 7. The data transmission control means of the data transmission device includes packet retransmission means for retransmitting a packet when a packet retransmission request is received, and retransmission packet storage means for storing a packet for retransmission. 7. The data transfer according to claim 5, wherein the data reception control means of the data receiving apparatus further comprises packet retransmission request means for requesting retransmission of the lost packet detected by the packet loss detection means. system. 8. A specific packet retransmission request unit for requesting a retransmission of a packet of a specific data stream that has been lost detected by the packet loss detection unit, instead of the packet retransmission request unit of the data receiving device. Data transfer system. 9. The data receiving apparatus according to claim 5, further comprising a receiving resolution changing unit for changing a receiving resolution in accordance with a packet loss state detected by the packet loss detecting unit. Data transfer system. 10. An arbitrary combination of the data transmission device according to any one of claims 1, 2, 3, 4, and 7, and the data reception device according to any one of claims 1, 2, and 4 to 9, A data transfer system consisting of a network that connects computers.