JP2007019953A - Video data transmission system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a video data transmission system which can reduce a processing load on a transmission side, and which can shorten a time from a request point to a time when a request video is displayed. <P>SOLUTION: A video data transmission system transmits video data to a terminal on the other end through a network. A system has a transmitting video data preparing means for preliminarily preparing linear transmission form video data of a form upon transmission to the network from the video data; a linear transmission form video data storing means for storing the prepared linear transmission form video data; and a transmission control means for transmitting the linear transmission form video data stored in the linear transmission form video data storing means without preparing the linear transmission form video data from the video data, when the transmission of the video data is required by the terminal on the other end. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a video data transmission system and can be applied to, for example, a system for transmitting general-purpose video data such as educational video data and maintenance video data to a videophone.

  Various systems for transmitting general-purpose video data to terminals capable of receiving both video data and audio data such as IP videophones and videophones have been developed and studied. For example, a maintenance service system that allows a user to obtain video data indicating a part replacement method of a certain apparatus (for example, a toner replacement method of a copier) via a video phone or a predetermined lecture is obtained. An e-learning system that transmits video data to a video phone or the like has been developed and studied.

  Conventionally, in order to output the contents of a general video data file that can be played back on a personal computer or the like in the Windows Media format (software name of Microsoft Corporation) to a partner terminal by communication, as shown in FIG. In the transmission apparatus 1, the video data file 2 is stored in the H.323 format corresponding to the communication partner. It was necessary to perform re-encoding to a compressed data format such as H.263 (S1) and further to store as payload data of a data transfer protocol such as RTP (S2) and then send it to the network (for example, , See Patent Document 1).

FIG. 2 shows an example in which the transfer destination terminal is the video phone 3 or the IP video phone 4. The video phone 3 is connected to the video data transmission device 1 via the video phone network 5 which is an ISDN network, the gateway 6 which performs format conversion between IP and ISDN, and the LAN 7. The IP video phone 4 is connected to the IP network 8, The video data transmitting apparatus 1 is connected via the LAN 7.
JP 2005-039342 A

  However, in the conventional general-purpose video data transmission method, encoding processing of video data files is required for each communication channel. Therefore, in a service for transmitting general-purpose video data, the number of channels for transmitting video data is set. There has been a problem that the load on devices (computers such as personal computers and servers) that provide the service in proportion increases.

  Also, since the video data is encoded after the communication channel is established, it takes time from the establishment of the communication channel until the video is played back on the terminal that receives and displays the video data such as a video phone or an IP video phone. There was a case.

  Therefore, there is a demand for a video data transmission system that can reduce the processing load on the transmission side and shorten the time from the request point in time until the requested video is displayed.

  According to the present invention, in a video data transmission system for transmitting video data to a partner terminal via a network, (1) line transmission format video data in a format for sending to the network is created in advance from the video data. Transmission video data creation means; (2) line transmission format video data storage means for storing the line transmission format video data created by the transmission video data creation means; and (3) video data from the counterpart terminal. Transmission control means for transmitting the line transmission format video data stored in the line transmission format video data storage means without generating the line transmission format video data from the video data when transmission is requested; It is characterized by having.

  According to the video data transmission system of the present invention, the line transmission format video data is created before the transmission of the video data is requested, and the line transmission created when the transmission of the video data is requested. Since the format video data is transmitted, the processing load on the transmission side can be reduced, and the time from the request point in time until the request video is displayed can be shortened.

(A) Embodiment Hereinafter, an embodiment of a video data transmission system according to the present invention will be described with reference to the drawings.

(A-1) Configuration of Embodiment FIG. 1 shows the overall configuration of a video data transmission system of this embodiment, and the same and corresponding parts as those in FIG. .

  In FIG. 1, the video data transmission system 10 of this embodiment functionally includes a video data transmission device 11 and a transmission video data creation device 12. In the example shown in FIG. 11 and the transmission video data creation device 12 are both connected to the LAN 7.

  The transmission video data creation device 12 uses a plurality of types of lines with different rates from the same original video data file OF made up of moving images or still images (the example in FIG. 1 is three types, and will be described as three types hereinafter). Transmission format video data files (transmission video data files) SFH, SFM, and SFL are created. The video data transmission device 11 stores the three types of line transmission format video data files SFH, SFM, SFL created by the transmission video data creation device 12, and according to the device capability of the user who requested the video data, 3 Among the types of line transmission format video data files SFH, SFM, and SFL, what is to be transmitted is determined and transmitted.

  Here, as will be described later, the line transmission format video data files SFH, SFM, SFL hold data on the data transfer protocol to be transmitted on the line using the format.

  The transmission video data creation device 12 is configured by, for example, the same server as the server configuring the video data transmission device 11 or a different server. Note that the transmission video data creation device 12 may be configured as a client of the video data transmission device 11. The transmission video data creation apparatus 12 includes a control unit, a communication unit, a storage medium access unit, an input unit, a display unit, and the like, which are functionally configured in terms of hardware. Has a configuration as shown in FIG.

  In FIG. 3, the transmission video data creation device 12 includes an original video data file storage unit 20, three types of encoding units 21H, 21M, and 21L, three types of transfer protocol header addition units 22H, 22M, and 22L, and three types of data. The header adding units 23H, 23M, and 23L have three types of line transmission format video data file storage units 24H, 24M, and 24L, and a file transfer unit 25.

  The original video data file storage unit 20 stores an original video data file OF in a general format such as a Windows Media format or a bitmap format. The original video data file OF may be input via a storage medium, may be input by transfer from an external device, and is on a server constituting the transmission video data creation device 12. It may be created in

  The encoding units 21H, 21M, and 21L are for high rate, medium rate, and low rate, respectively. It encodes each frame into compressed data of the H.263 format or other formats, and adds a payload header. The encoding units 21H, 21M, and 21L divide the frame if the size of one frame is larger than the limit of the network protocol to be used. The data for each frame (data for each divided frame in the case of division) is video data of one unit of the line transmission format video data file SF (SFH, SFM, SFL) shown in FIG. 4 and its payload header portion R3. It has become.

  The transfer protocol header addition units 22H, 22M, and 22L add the RTP header or other data transfer protocol header to the frame unit encoded by the corresponding encoding unit 21H, 21M, or 21L (or the divided frame unit when divided). To do. This is the data transfer protocol header portion of data 1 unit of the line transmission format video data file SF shown in FIG.

  The data header adding units 23H, 23M, and 23L add data headers in units of data transfer protocol headers added by the corresponding transfer protocol header adding units 22H, 22M, and 22L. The additional contents of the data header are the data delimiter, the size of each data unit, the data transmission interval, and the control data necessary for the video data transmitting apparatus 11. The data header addition units 23H, 23M, and 23L write the data to the corresponding line transmission format video data file storage units 24H, 24M, and 24L so that the data is in order for each unit.

  The line transmission format video data file storage units 24H, 24M, and 24L store the created line transmission format video data files SFH, SFM, and SFL. Note that the three types of line transmission format video data file storage units 24H, 24M, and 24L do not need to be separated in terms of hardware, but may be separated in terms of functions.

  The line transmission format video data files SFH, SFM, and SFL stored in the line transmission format video data file storage units 24H, 24M, and 24L in this way are, as shown in FIG. 4, data header portion R1, data transfer protocol, respectively. One unit of data composed of the header part R2, the video data, and the payload header part R3 has a number corresponding to the capacity of the original video data file OF.

  The file transfer unit 25 transfers the line transmission format video data files SFH, SFM, and SFL stored in the line transmission format video data file storage units 24H, 24M, and 24L to the video data transmission apparatus 11 via the LAN 7. . Here, the file transfer unit 25 may be transferred by a request from the video data transmitting apparatus 11, and is automatically transferred when the creation of the line transmission format video data files SFH, SFM, SFL is completed. Alternatively, it may be transferred in accordance with an operator's operation on the transmission video data creation device 12. The video data transmitting apparatus 11 may be provided with line transmission format video data files SFH, SFM, and SFL using a storage medium.

  The video data transmitting apparatus 11 is configured by a server, for example, and includes a control unit including a CPU, a ROM, a RAM, a communication unit, a storage medium access unit, an input unit, a display unit, and the like in hardware. However, from the viewpoint of the relationship with the features of the embodiment, functionally, the configuration shown in FIG.

  5, the video data transmitting apparatus 11 includes a communication unit 30, a transfer control unit 31, a line transmission format video data file storage unit 32H, 32M, and 32L, and a user information storage unit 33. An appropriate number of these components are provided so that parallel transmission to a plurality of users is possible.

  The communication unit 30 corresponds to, for example, a LAN interface unit, and exchanges communication data (IP packets) with the LAN 7.

  The transfer control unit 31 has three types of line transmission format video data files SFH stored in the line transmission format video data file storage units 32H, 32M, and 32L in response to a request from the video phone 3 or the IP video phone 4 side. Either SFM or SFL is transmitted to the video phone 3 or IP video phone 4 side. For example, at the time of transfer, the transfer control unit 31 reads a line transmission format video data file, and transmits the read contents to the line (LAN 7) as network protocol data such as UDP or TCP in order for each data unit. . The transfer control unit 31 includes a determination unit 31A that determines which of the three types of line transmission format video data files SFH, SFM, and SFL is to be transmitted.

  When the line transmission format video data files SFH, SFM, SFL are given by file transfer from the transmission video data creation device 12, the transfer control unit 31 receives the line transmission format video data files SFH, SFM, The SFL is also stored in the line transmission format video data file storage units 32H, 32M, and 32L.

  The line transmission format video data file storage units 32H, 32M, and 32L store the transferred line transmission format video data files SFH, SFM, and SFL. Again, the three types of line transmission format video data file storage units 32H, 32M, and 32L do not need to be separated in terms of hardware, but may be functionally separated.

  The user information storage unit 33 stores user information that can request transfer of a video data file. The user information storage unit 33 stores, for example, information that the transfer control unit 31 applies to user authentication.

(A-2) Operation | movement of embodiment Next, operation | movement of the video data transmission system 10 of embodiment which has the above structures is demonstrated.

  In the video data transmission system 10 of the embodiment, first, the transmission video data creation device 12 creates three types of line transmission format video data files SFH, SFM, SFL from the original video data file OF, and then the video data. One of the line transmission format video data files SFH, SFM or SFL is sent to the line by the transmission device 11.

  The transmission video data creation device 12 takes in an original video data file OF in a general format, encodes the original video data file OF into compressed data for each frame, and adds a payload header. Next, a data transfer protocol header is added to each encoded frame. Next, a data header is added to each data transfer protocol header. Then, the data is written in the line transmission format video data file so as to be in order for each unit, thereby completing the line transmission format video data file.

  As such a line transmission format video data file, a plurality of types (three types in this embodiment) having different rates are created. That is, a high rate line transmission format video data file SFH, a medium rate line transmission format video data file SFM, and a low rate line transmission format video data file SFL are created.

  The created three types of line transmission format video data files SFH, SFM, and SFL are transferred from the transmission video data creation device 12 to the video data transmission device 11.

  When there is a transfer request for the video data file from the video phone 3 or the IP video phone 4 side, the video data transmitting device 11 performs user authentication and then performs three types of line transmission format video data files SFH, SFM, SFL. Is determined to be transmitted to the video telephone 3 or IP video telephone 4 side, and the determined line transmission format video data file is transmitted to the line.

  The transmission operation is as follows. First, the video data transmitting apparatus 11 reads the corresponding line transmission format video data file SF (SFH, SFM or SFL). Next, for each data unit shown in FIG. 4, the data transfer protocol header part R2, the video data and its payload header part R3 are extracted. Next, the extracted data is set as a data portion of UDP, TCP, or other network protocol and transmitted to the line. At this time, data is transmitted according to a time stamp (data transmission interval or time from the top data) set in the data header portion R1.

  FIG. 6 is an explanatory diagram showing an example of a method for determining a line transmission format video data file to be transmitted to the video phone 3. The line transmission format video data file to be transmitted to the IP video phone 4 may be fixed (for example, a high-rate line transmission format video data file SFH), and is almost the same as in the case of FIG. Similarly, the line transmission format video data file to be transmitted may be determined.

  When the video channel with the video phone 3 is established (S100), the video data transmitting apparatus 11 periodically (for example, every 30 seconds) periodically sends a unique rate check packet (for example, a packet to be looped back) to the partner terminal side. ) Is transmitted (S101, S104, S107, S110). For such a rate check packet, the gateway 6 that terminates the IP packet (terminates the LAN 7) responds and returns a response packet. When the video data transmitting apparatus 11 receives the response packet (S102, S105, S108, S111), based on the response time interval of the packet (time from the transmission time to the reception time), the video data transmission device 11 And the data of the line transmission format video data file SFH, SFM or SFL corresponding to the determination rate is transmitted (S103, S106, S109, S112). For example, the range of response time intervals for determining high rate, medium rate, and low rate is determined in advance, and rate determination is performed.

  FIG. 6 shows a case where the four determination results are a high rate, a medium rate, a low rate, and a high rate. Here, when the line transmission format video data file for transmission is switched halfway, the switching is executed while compensating for the continuity of the video based on the information of various header parts in the data.

  Instead of the method using the response time interval as described above, a packet for returning the line rate is sent to the gateway 6 as a rate check packet transmitted by the video data transmitting device 11 (in the case of the IP videophone 7 (IP network 8), RTCP may be used), and a line transmission format video data file for transmission may be determined based on the line rate returned in the reply packet. .

  Instead of sending rate check packets periodically as described above, rate determination may be performed only once immediately after the establishment of the video channel.

(A-3) Effects of Embodiment According to the video data transmission system of the embodiment, the following effects can be obtained.

  The video data transmission apparatus eliminates the need for encoding processing, can reduce the load on the apparatus, and shortens the time from establishment of a communication channel with a partner terminal (IP videophone or videophone) to video output. I can expect that.

  Here, in the transmission video data creation device, when the line transmission format video data file SF is created, a plurality of different quality video data is created according to the specified encoding parameters (bit rate, frame rate and image quality). Thus, the video data transmitting apparatus can select and transmit a video data file of a line transmission format that matches the performance of the connected line to the line.

  Further, even when the compression method of video compressed data and the data transfer protocol are changed, it is not necessary to change the video data transmitting apparatus, and the system version can be easily changed.

  Furthermore, video data at an appropriate rate can be transmitted by periodically checking the capability of the connection partner after establishing the communication channel and selecting an optimal data file.

(B) Other Embodiments In the description of the above-described embodiment, various modified embodiments have been referred to. However, modified embodiments as exemplified below can be cited.

  In the above embodiment, the case where three types of line transmission format video data files are created from the same original video data file is shown, but the number of types is not limited to three, and any number of types of one or more can be created. May be.

  Further, in the above embodiment, the type of determining which type of line transmission format video data file is to be transmitted by transmitting the rate check packet and receiving the response packet has been described. However, other determination methods may be applied. May be. For example, the designated rate may be taken from the partner terminal when the call control packet is exchanged with the partner terminal when establishing the video channel. For example, the specified rate information may be included in the user information for authentication so that the specified rate is recognized during the authentication process.

  Furthermore, although the number of types of original video data files is shown in the above embodiment, there may be a plurality of types of original video data files. In this case, when the video channel is established, first, the type of the original video data file is designated on the counterpart terminal side. Here, a still image and a moving image may be mixed as the original video data file. In any case, the original video data file is converted into a line transmission format video data file having the data structure shown in FIG.

  Furthermore, in the above embodiment, the case where the counterpart terminal is a video phone and an IP video phone has been shown. However, since it is a video data communication, a terminal having no voice processing function (for example, a telephone function or the like is installed). Not a computer).

  In the above embodiment, the original data file used for transmission is a video data file. However, it may be a video / audio composite data file. In this case, the composite data file is separated into a video data file and an audio data file, and the creation process described in the above embodiment is performed on the video data file. For audio data, the following two types of methods are used. First, audio data corresponding to the video portion is added to the end of one unit of the data of the line transmission format video data file, and the audio data is also transmitted through the video channel. Second, an audio channel separate from the video channel is established, and video and audio data are transmitted in parallel.

  Further, in the above embodiment, the transmission of one type of a plurality of types of line transmission format video data files that have been created in advance has been shown, but the capability, specifications, etc. of the counterpart terminal have been created in advance. In special cases, such as when the consistency with the line transmission format video data file is poor, a new type of line transmission format video data file may be created and sent after the video data file is requested. good. A new type of line transmission format video data file transmitted in this way may also be stored, and thereafter used as a selection candidate.

1 is a block diagram illustrating an overall configuration of a video data transmission system according to an embodiment. It is explanatory drawing of the process of the conventional video data transmission apparatus. It is a block diagram which shows the functional structure of the video data production apparatus for transmission of embodiment. It is explanatory drawing which shows the structure of the line transmission format video data file of embodiment. It is a block diagram which shows the functional structure of the video data transmission apparatus of embodiment. It is explanatory drawing which shows an example of the determination method of the line transmission format video data file transmitted to the video telephone of embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Video data transmission system, 11 ... Video data transmission apparatus, 12 ... Transmission video data creation apparatus, 20 ... Original video data file storage part, 21H, 21M, 21L ... Encoding part, 22H, 22M, 22L ... Transfer protocol header Addition unit, 23H, 23M, 23L ... Data header addition unit, 24H, 24M, 24L, 32H, 32M, 32L ... Line transmission format video data file storage unit, 25 ... File transfer unit, 30 ... Communication unit, 31 ... Transfer control Unit 33... User information storage unit.

Claims (3)

In a video data transmission system that transmits video data to a partner terminal via a network,
From the video data, transmission video data creation means for creating line transmission format video data in a format for sending to the network in advance,
Line transmission format video data storage means for storing the line transmission format video data created by the transmission video data creation means;
The line transmission format video stored in the line transmission format video data storage means without creating the line transmission format video data from the video data when transmission of video data from the partner terminal is requested. A video data transmission system comprising: a transmission control means for transmitting data. The transmission video data creation means creates a plurality of types of line transmission format video data from the same video data,
The transmission format video data storage means stores the plurality of types of line transmission format video data,
The transmission control means selects one type from a plurality of types of the line transmission format video data stored in the line transmission format video data storage means when transmission of video data from the partner terminal is requested. The video data transmission system according to claim 1, wherein the video data transmission system is selected and transmitted to the partner terminal. 3. The video data transmission system according to claim 2, wherein the transmission control means measures the state of the communication channel and dynamically reviews the type of the selected line transmission format video data.

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