Patent Publication Number: US-2015082359-A1

Title: Distribution management apparatus and distribution management system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority to and incorporates by reference the entire contents of Japanese Patent Application No. 2013-190689 filed in Japan on Sep. 13, 2013. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a distribution management apparatus and a distribution management system. 
     2. Description of the Related Art 
     A system is known that, when a specific position or part in content being reproduced is designated, can provide information related to the content (refer to Japanese Laid-open Patent Publication No. 2009-65551, for example). In Japanese Laid-open Patent Publication No. 2009-65551, content and related information corresponding to any element in the content are registered in advance in a database in a server. When receiving the content and designation information for a specific element within the content from a terminal that is supplied with the content, the server transmits the corresponding information to the terminal. 
     However, it has been conventionally required to register elements included in content to be distributed and related information in association with each other in advance. Because of this, in the case where a communication terminal serving as a projector, for example, reproduces video and another communication terminal draws operation paths such as characters in a memorandum, lines, and images, conventionally, the operation paths and the video being reproduced cannot be associated with each other. In other words, it has been conventionally difficult to dynamically associate operation paths such as lines and images drawn by a user with one communication terminal and information on video being reproduced by another communication terminal with each other. 
     Therefore, there is a need to provide a distribution management apparatus and a distribution management system that can dynamically associate an operation path drawn by one communication terminal with information on video being reproduced by another communication terminal. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to at least partially solve the problems in the conventional technology. 
     According to an embodiment, there is provided a distribution management apparatus that includes a generating unit configured to render content data to generate video data; a converter configured to convert a data format of the video data into a data format allowing the video data to be distributed to communication terminals including a first communication terminal and a second communication terminal; a transmitter/receiver configured to distribute the converted video data to the communication terminals; a receiver configured to receive path information indicating an operation path drawn by the first communication terminal and a drawing timing of the operation path from the first communication terminal; an acquiring unit configured to acquire identification information that identifies content data corresponding to video data reproduced by the second communication terminal at the drawing timing; and a storage unit configured to store therein the path information and the identification information in association with each other. 
     According to another embodiment, there is provided a distribution management system that includes a distribution management apparatus and communication terminals including a first communication terminal and a second communication terminal connected to the distribution management apparatus through a network. The distribution management apparatus includes a generating unit configured to render content data to generate video data; a converter configured to convert a data format of the video data into a data format allowing the video data to be distributed to the communication terminals including the first communication terminal and the second communication terminal; a transmitter/receiver configured to distribute the converted video data to the communication terminals; a receiver configured to receive path information indicating an operation path drawn by the first communication terminal and a drawing timing of the operation path from the first communication terminal; an acquiring unit configured to acquire identification information that identifies content data corresponding to video data reproduced by the second communication terminal at the drawing timing; and a storage unit configured to store therein the path information and the identification information in association with each other. 
     The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a distribution system according to an embodiment; 
         FIG. 2  is a conceptual view when a dongle is attached to a communication terminal; 
         FIG. 3  is a conceptual diagram illustrating a basic distribution method; 
         FIG. 4  is a conceptual diagram of multicast; 
         FIG. 5  is a conceptual diagram of multidisplay; 
         FIG. 6  is a conceptual diagram of composite distribution; 
         FIG. 7  is a diagram illustrating an example of hardware configuration of a distribution management apparatus; 
         FIG. 8  is a functional block diagram illustrating functions of the distribution management apparatus; 
         FIG. 9  is a conceptual diagram of a drawing table; 
         FIG. 10  is a functional block diagram illustrating mainly the functions of the communication terminal; 
         FIG. 11  is a functional block diagram illustrating the functions of the terminal management apparatus; 
         FIG. 12  is a conceptual view of a distribution destination selection menu screen; 
         FIG. 13  is a conceptual view of a terminal management table; 
         FIG. 14  is a conceptual view of an available terminal management table; 
         FIG. 15  is a detailed diagram of an encoder bridge unit; 
         FIG. 16  is a functional block diagram illustrating the functions of a convertor; 
         FIG. 17  is a sequence diagram illustrating the basic distribution processing of the distribution management apparatus; 
         FIG. 18  is a sequence diagram illustrating the processing of time adjustment performed between the distribution management apparatus and a communication terminal; 
         FIG. 19  is a sequence diagram illustrating the processing of channel adaptive control on data transmitted from the distribution management apparatus to the communication terminal; 
         FIG. 20  is a sequence diagram illustrating the processing of channel adaptive control on data transmitted from the communication terminal to the distribution management apparatus; 
         FIG. 21  is a sequence diagram illustrating the processing of multidisplay; 
         FIG. 22  is a sequence diagram illustrating the processing of multidisplay; 
         FIG. 23  is a sequence diagram illustrating the processing of multidisplay; 
         FIG. 24  is a sequence diagram illustrating remote sharing processing with the distribution management apparatus; and 
         FIG. 25  is a flowchart illustrating drawing processing. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Described below with reference to the accompanying drawings is a distribution system according to an embodiment. The following embodiment is an application example of a distribution system that converts web content into video data, sound data, or video and sound data, and distributes the data to communication terminals such as personal computers and electronic blackboards using cloud computing. In the following, when indicating at least either one of video and sound, it will be represented as “video (sound)”. 
     Outline of System Configuration 
     Described first is an outline of the configuration of the distribution system  1 . 
       FIG. 1  is a schematic diagram of a distribution system  1  according to the present embodiment. As illustrated in  FIG. 1 , the distribution system  1  according to the present embodiment is constructed by a distribution management apparatus  2 , a plurality of communication terminals  5   a  to  5   f , a terminal management apparatus  7 , and a web server  8 . In the following, any communication terminal among the communication terminals  5   a  to  5   f  is represented as a “communication terminal  5 ”. The distribution management apparatus  2 , the terminal management apparatus  7 , and the web server  8  are all constructed by server computers. 
     The communication terminal  5  is a terminal used by a user who receives services of the distribution system  1 . The communication terminal  5   a  is a notebook personal computer (PC). The communication terminal  5   b  is a mobile terminal such as a smartphone and a tablet terminal. The communication terminal  5   c  is a multifunction peripheral/printer/product (MFP) in which the functions of copying, scanning, printing, and faxing are combined. The communication terminal  5   d  is a projector. The communication terminal  5   e  is a TV (video) conference terminal having a camera, a microphone, and a speaker. The communication terminal  5   f  is an electronic blackboard (whiteboard) that can receive operation paths drawn by the user and electronically convert the operation paths. 
     The communication terminal  5  may be not only the terminals illustrated in  FIG. 1 , but also a watch, an automatic vendor, a gas meter, a car navigation device, a game machine, an air conditioner, a lighting fixture, a camera unit, a microphone unit, and a speaker unit. 
     The distribution management apparatus  2 , the communication terminal  5 , the terminal management apparatus  7 , and the web server  8  can communicate with each other through a communication network  9  such as the Internet and a local area network (LAN). The communication network  9  includes wireless communication networks such as 3rd Generation (3G), Worldwide Interoperability for Microwave Access (WiMAX), and Long-Term Evolution (LTE). 
     The communication terminal  5 , like the communication terminal  5   d , may not have a function of communicating with the other terminals and systems through the communication network  9 . However, as illustrated in  FIG. 2 , a user inserts a dongle  99  into an interface of Universal Serial Bus (USB) or High-Definition Multimedia Interface (HDMI) (registered trademark) of the communication terminal  5   d , thereby allowing it to communicate with the other terminals and systems.  FIG. 2  is a conceptual view when the dongle  99  is attached to the communication terminal. 
     The distribution management apparatus  2  includes what is called a cloud browser (hereinafter, referred to as a “browser  20 ”) as a web browser present on a cloud. The distribution management apparatus  2  renders web content on the cloud with the browser  20  to produce video (sound) data conforming to H.264 or MPEG-4, and distributes it to the communication terminal  5 . 
     The distribution management apparatus  7  has a function as a management server and performs, for example, login authentication on the communication terminal  5  and management of the contract information of the communication terminal  5 . The terminal management apparatus  7  has a function of a Simple Mail Transfer Protocol (SMTP) server for transmitting e-mails. The terminal management apparatus  7  can be embodied as, for example, an imaginary machine developed on a cloud service (IaaS: Infrastructure as a Service). It is desirable that the terminal management apparatus  7  be operated in a multiplexed manner in order to address unexpected incidents to perform continuous service provision. 
     The browser  20  of the distribution management apparatus  2  enables real-time communication/collaboration (RTC). In addition, an encoder bridge unit  30  of the distribution management apparatus  2  described below includes an encoding unit  19  (refer to  FIG. 15  described later). Although the details will be described later, the encoding unit  19  can real-time encode the video (sound) data generated by the browser  20 . As a result, the processing of the distribution management apparatus  2  is different from, for example, a case in which non real-time video (sound) data recorded in a DVD is read and distributed by a DVD player. 
     Outline of Various Kinds of Distribution Methods 
     Described next is an outline of various kinds of distribution methods. 
     Basic Distribution 
       FIG. 3  is a conceptual diagram illustrating a basic distribution method of the distribution system  1  according to the present embodiment. In the distribution system  1 , as illustrated in  FIG. 3 , the browser  20  of the distribution management apparatus  2  acquires web content data [A] from the web server  8  and renders it, thereby generating pieces of video (sound) data [A]. The encoder bridge unit  30  encodes the video (sound) data [A] and transmits it to the communication terminal  5 . Hence, even when generated web content in accordance with Hyper Text Markup Language (HTML), Cascading Style Sheets (CSS), or the like is rich, the web content is distributed as the video (sound) data conforming to H.264 or MPEG-4, thereby enabling even a low specification communication terminal  5  to smoothly reproduce video (sound). The distribution system  1  according to the present embodiment updates the browser  20  of the distribution management apparatus  2 , thereby enabling the latest rich web content to be reproduced on the communication terminal  5  without updating a local browser thereof. 
     As illustrated in  FIG. 4  to  FIG. 6 , the distribution system  1  can also distribute web content as video (sound) data to a plurality of communication terminals  5  in the same site or in a plurality of sites by adapting the above distribution method. The following describes the distribution method illustrated in  FIG. 4  to  FIG. 6 . 
     Multicast 
       FIG. 4  is a conceptual diagram of multicast. As illustrated in  FIG. 4 , the single browser  20  of the distribution management apparatus  2  acquires the web content data [A] from the web server  8  and renders it, thereby generating pieces of video (sound) data [A]. The encoder bridge unit  30  encodes the pieces of video (sound) data [A]. The distribution management apparatus  2  then distributes the video (sound) data [A] to a plurality of communication terminals  5   f   1 ,  5   f   2 ,  5   f   3 . Hence, for example, the communication terminals  5   f   1 ,  5   f   2 ,  5   f   3  in the plurality of sites can output the same video (sound). In this case, the communication terminals  5   f   1 ,  5   f   2 ,  5   f   3  do not need to have the same display reproduction capability (e.g., the same resolution). The distribution method like this is called, for example, “multicast”. 
     Multidisplay 
       FIG. 5  is a conceptual diagram of multidisplay. As illustrated in  FIG. 5 , the single browser  20  of the distribution management apparatus  2  acquires web content data [XYZ] from the web server  8  and renders it, thereby generating one piece of video (sound) data [XYZ]. The encoder bridge unit  30  divides one piece of video (sound) data [XYZ] into a plurality of pieces of video (sound) data [X], [Y], [Z] and then encodes them. Subsequently, the distribution management apparatus  2  distributes the divided video (sound) data [X] to the communication terminal  5   f   1 . Similarly, the distribution management apparatus  2  distributes the divided video (sound) data [Y] to the communication terminal  5   f   2  and distributes the divided video (sound) data [Z] to the communication terminal  5   f   3 . Thus, for example, even for landscape web content data [XYZ], video is displayed by the communication terminals  5   f   1 ,  5   f   2 ,  5   f   3  in a divided manner. As a result, when the communication terminals  5   f   1 ,  5   f   2 ,  5   f   3  are installed in a line, the same effect as the display of one piece of large video can be obtained. In this case, the communication terminals  5   f   1 ,  5   f   2 ,  5   f   3  need to have the same display reproduction capability (e.g., the same resolution). The distribution method like this is called, for example, “multidisplay”. 
     Composite Distribution 
       FIG. 6  is a conceptual diagram of composite distribution using a plurality of communication terminals  5  through a distribution management apparatus  2 .  FIG. 6  is also a conceptual diagram of remote sharing processing. As illustrated in  FIG. 6 , at a first site (the right side in  FIG. 6 ), the communication terminal  5   f   1  as an electronic blackboard and a communication terminal  5   e   1  as a TV conference terminal are used, and at a second site (the left side in  FIG. 6 ), the communication terminal  5   f   2  as an electronic blackboard and a communication terminal  5   e   2  as a TV conference terminal are used similarly. At the first site, an electronic pen P 1  is used for displaying operation information such as characters with operation paths on the communication terminal  5   f   1 . At the second site, an electronic pen P 2  is used for displaying operation information such as characters with operation paths on the communication terminal  5   f   2 . In the example illustrated in  FIG. 6 , at the first site, the communication terminal  5   e   1  as the TV conference terminal is connected to the communication terminal  5   f   1  as the electronic blackboard, and a camera/microphone/speaker of the communication terminal  5   e   1  is used as an external camera/microphone/speaker of the communication terminal  5   f   1 . Similarly, at the second site, the communication terminal  5   e   2  as the TV conference terminal is connected to the communication terminal  5   f   2  as the electronic blackboard, and a camera/microphone/speaker of the communication terminal  5   e   2  is used as an external camera/microphone/speaker of the communication terminal  5   f   2 . 
     At the first site, video (sound) data [E1] acquired by the communication terminal  5   e   1  is encoded by an encoding unit  60  and is then transmitted to the distribution management apparatus  2 . After that, it is decoded by a decoding unit  40  of the distribution management apparatus  2  and is then input to the browser  20 . Operation information [p1] indicating the operation paths drawn by the communication terminal  5   f   1  with the electronic pen P 1  or the like is transmitted to the distribution management apparatus  2  to be input to the browser  20 . Also at the second site, video (sound) data [E2] acquired by the communication terminal  5   e   2  is encoded by the encoding unit  60  and is then transmitted to the distribution management apparatus  2 . After that, it is decoded by the decoding unit  40  of the distribution management apparatus  2  and is then input to the browser  20 . Operation information [p2] such as the operation paths drawn by the communication terminal  5   f   2  with the electronic pen P 2  is transmitted to the distribution management apparatus  2  to be input to the browser  20 . 
     The browser  20 , for example, acquires web content data [A] representing a background image to be displayed on the respective displays of the communication terminals  5   f   1 ,  5   f   2  from the web server  8 . The browser  20  combines and renders the web content data [A], the operation information [p1], [p2], and the video (sound) data [E1], [E2], thereby generating video (sound) data installed with a desired layout. The encoder bridge unit  30  encodes the video (sound) data, and the distribution management apparatus  2  distributes the same video (sound) data to the respective sites. At the first site, thereby, video ([A], [p1], [p2], [E1 (video part)] and [E2] (video part) are displayed on the display of the communication terminal  5   f   1 , and a sound [E2 (sound part)] is output from the speaker of the communication terminal  5   e   1 . Also at the second site, video ([A], [p1], [p2], [E1 (video part)] and [E2] (video part) are displayed on the display of the communication terminal  5   f   2 , and a sound [E1 (sound part)] is output from the speaker of the communication terminal  5   e   2 . At the first site, the sound of the site itself [E1 (sound part)] is not output owing to an echo cancelling function of the communication terminal  5   f   1 . At the second site, the sound of the site itself [E2 (sound part)] is not output owing to an echo cancelling function of the communication terminal  5   f   2 . 
     Thus, at the first site and the second site, remote shared processing can be performed that shares the same information in real time at remote sites, thus making the distribution system  1  according to the present embodiment effective in a teleconference or the like. 
     Detailed Description of the Embodiment 
     Described next with reference to  FIG. 7  to  FIG. 25  is Detailed Description of the Embodiment. 
     Hardware Configuration of the Embodiment 
     Described first with reference to  FIG. 7  is the hardware configuration of the present embodiment.  FIG. 7  is a diagram illustrating an example of the hardware configuration of the distribution management apparatus  2 . Because the hardware configuration of the communication terminal  5 , the terminal management apparatus  7 , and the web server  8  is the same as the hardware configuration of the distribution management system  2  illustrated in  FIG. 7 , the description thereof will be omitted. 
     As illustrated in  FIG. 7 , the distribution management apparatus  2  includes: a CPU  201  that controls the entire operation of the distribution management system  2 ; a ROM  202  such as an initial program loader (IPL) that stores therein a program used for driving the CPU  201 ; a RAM  203  used as a work area of the CPU  201 ; an HDD  204  that stores therein various kinds of data such as programs; a hard disk controller (HDC)  205  that controls the reading and writing the various kinds of data from and into the HDD  204  under the control of the CPU  201 ; a media drive  207  that controls the reading and writing data from and into a storage medium  206  such as a flash memory; a display  208  that displays various kinds of information; an I/F  209  for transmitting data through the communication network  9  and connecting the dongle  99 ; a keyboard  211 ; a mouse  212 ; a microphone  213 , a speaker  214 , a graphics processing unit (GPU)  215 ; and a bus line  220  such as an address bus and a data bus for electrically connecting the above components. 
     The programs for the respective communication terminals, the respective systems, and the respective servers may be stored in computer-readable media such as the storage medium  206  and distributed as installable or executable files. 
     Functional Configuration of the Embodiment 
     Described next with reference to  FIG. 8  to  FIG. 16  is the functional configuration of the embodiment.  FIG. 8  is a functional block diagram illustrating the functions of the distribution management apparatus  2 .  FIG. 8  illustrates a functional configuration when the distribution management apparatus  2  distributes video (sound) data to the communication terminal  5   f   1  (corresponding to the first communication terminal) and the communication terminal  5   f   3  (corresponding to the second communication terminal). However, the functional configuration is similar for the distribution destination is other than the communication terminal  5   f   1  or the communication terminal  5   f   3 . Although the distribution management apparatus  2  includes a plurality of distribution engine servers, described below is a case when a 1 distribution engine server is included in order to simplify the description. 
     Functional Configuration of Distribution Management Apparatus 
     The distribution management apparatus  2  achieves the functional components illustrated in  FIG. 8  by the hardware configuration and the program exemplified in  FIG. 7 . Specifically, the distribution management apparatus  2  includes the browser  20 , a transmitter/receiver  21 , a browser management unit  22 , a transmission first-in first-out (FIFO)  24 , a time management unit  25 , a time acquisition unit  26 , a channel adaptive controller  27 , the encoder bridge unit  30 , a transmitter/receiver  31 , a reception FIFO  34 , a recognizing unit  35 , a delay information acquisition unit  37   a , a channel adaptive controller  37   b , and the decoding unit  40 . 
     The distribution management apparatus  2  further includes a storage unit  23  constructed by the HDD  204  illustrated in  FIG. 7 . This storage unit  23  stores therein recognition information  23 A described below output from the recognizing unit  35 . The content data acquired by the browser  20  can be temporarily stored in the storage unit  23  as a cache. The storage unit  23  stores therein path attribute information  23 B and a drawing table  23 C (which will be detailed below). 
     Among the above functional components, the browser  20  is a browser that operates within the distribution management apparatus  2 . The browser  20  renders content data such as web content data, thereby generating video (sound) data as RGB data (or pulse code modulation (PCM) data). The browser  20  is updated corresponding to the enrichment of web content at all times. 
     The distribution system  1  according to the present embodiment provides the browsers  20  within the distribution management apparatus  2 , and a cloud browser for use in a user session is selected from the browsers  20 . 
     The present embodiment describes a case when the distribution management apparatus  2  includes the browser  20   a  and the browser  20   b  as the browser  20 . The browser  20   a  is a browser  20  corresponding to the communication terminal  5   f   1 . The browser  20   b  is a browser  20  corresponding to the communication terminal  5   f   3 . When these browsers  20   a  and the browser  20   b  are collectively referred to, they are referred to as the browser  20 . 
     The browser  20  includes, for example, Media Player, Flash Player, JavaScript (registered trademark), CSS, and HTML Renderers. JavaScript (registered trademark) includes the standardized product and one unique to the distribution system  1 . Media Player is a browser plug-in for reproducing multimedia files such as video (sound) files within the browser  20 . Flash Player is a browser plug-in for reproducing flash content within the browser  20 . The unique JavaScript (registered trademark) is a JavaScript set that provides the application programming interface (API) of services unique to the distribution system  1 . CSS is a technique for efficiently defining the appearance and style of web pages described in HTML. HTML Renderer is an HTML rendering engine. 
     The transmitter/receiver  21  transmits and receives various kinds of data, various kinds of requests, various kinds of instructions, and the like to and from the terminal management apparatus  7  and the web server  8 . For example, the transmitter/receiver  21  acquires web content data from a content site of the web server  8 . 
     The browser management unit  22  manages the browser  20  and the encoder bridge unit  30 . For example, the browser management unit  22  instructs the browser  20  and the encoder bridge unit  30  to start up and exit and numbers an encoder ID at startup or exit. The encoder ID is identification information the browser management unit  22  numbers in order to manage the process of the encoder bridge unit  30 . The browser management unit  22  numbers and manages a browser ID every time the browser  20  is started up. The browser ID is identification information the browser management unit  22  numbers in order to manage the process of the browser  20  to identify the browser  20 . 
     The browser management unit  22  acquires various kinds of operation information [p] from the communication terminal  5  through the transmitter/receiver  31  and outputs them to the browser  20   a . The browser  20   a  includes an acquiring unit  201 . The acquiring unit  201  acquires the operation information [p] from the communication terminal  5   f   1  through the browser management unit  22  and the transmitter/receiver  31 . 
     The operation information [p] is operation events (instruction information through the keyboard  211 , the mouse  212 , or other devices, and operation paths through the electronic pen P, the mouse  212 , or other devices) on the communication terminal  5 . 
     In the present embodiment, the operation information [p] includes a terminal ID indicating the communication terminal  5  as a transmission source, path information, drawing timing, and instruction information. 
     The path information is information indicating operation paths such as characters, lines, and images drawn by the operation of the electronic pen P or the like by the user on the communication terminal  5 . The path information includes a set of position coordinates on a page (display screen) indicating paths and path attribute information. 
     The path attribute information indicates display forms of operation paths such as the line type (a dotted line, a dashed line, or the like) of an operation path, the thickness of the path, and the color of the path. 
     The drawing timing indicates timing when an operation path has been drawn by the user. The drawing timing is represented by, but not limited to, a time, an elapsed time from the start of reproduction in video being reproduced, a reproduction position (such as a frame), or other indexes. 
     The instruction information is information indicating processing contents instructed by the user who operates the communication terminal  5 . In the present embodiment, the instruction information includes a drawing processing instruction indicating drawing processing, a drawing mode indicating new drawing, an erasing mode indicating the erasing of drawn drawing, or a menu processing instruction. 
     When the instruction information includes the erasing mode, the operation information [p] includes the position information of the operation path of an object to be erased on the screen in place of the path information and the drawing timing. 
     The browser  20   a  performs the drawing processing described below based on the operation information acquired by the acquiring unit  201 . This drawing processing updates the drawing table  23 C in the storage unit  23 . The drawing processing will be described in detail below. 
       FIG. 9  is a conceptual diagram of the drawing table  23 C. The drawing table  23 C is a table that associates a terminal ID, setting information indicating a home uniform resource locator (URL), path information, and identification information. 
     The terminal ID is identification information uniquely identifying the communication terminals  5 . The setting information indicates the home URL of the communication terminal  5  identified by the corresponding terminal ID. The setting information is an URL indicating an access destination to the browser  20  corresponding to each communication terminal  5 . 
     In the present embodiment, the drawing table  23 C stores therein coordinates on a page and path images generated from the path information included in the operation information [p] acquired from the communication terminal  5 . The path image is a command indicating a drawing instruction of an image indicating an operation path generated by the browser  20   a  from the path information included in the operation information [p]. When the path attribute information included in the path information indicates that the operation path is a thick, red wavy line, for example, a drawing instruction of an image that indicates this thick, red wavy line and continues a set of position coordinates indicating the path is the path image. The coordinates on a page stored in the drawing table  23 C indicate the drawing starting position of the operation path. 
     The identification information is information for identifying content data corresponding to video data that is reproduced by another communication terminal  5  (the communication terminal  5   f   3 , for example) as an object of remote sharing processing at the drawing timing included in the operation information [p] received from one communication terminal (the communication terminal  5   f   1 , for example). In the present embodiment, the identification information includes a destination URL and a destination URL terminal ID. The destination URL indicates the setting information (home URL) of the communication terminal  5  as the object of remote sharing processing to which video (sound) data based on the content data is being distributed. The destination URL terminal ID is the terminal ID of the communication terminal  5 . 
     Returning back to  FIG. 8 , when the communication terminal  5  provides various sensors such as a temperature sensor, a humidity sensor, or an acceleration sensor, the browser management unit  22  acquires sensor information that is an output signal of the sensors from the communication terminal  5  and outputs it to the browser  20 . 
     The transmission FIFO  24  is a buffer that stores therein the pieces of video (sound) data generated by the browser  20 . In the present embodiment, the distribution management apparatus  2  includes a transmission FIFO  24   a  and a transmission FIFO  24   b . The transmission FIFO  24   a  is a buffer that stores therein video (sound) data generated by the browser  20   a . The transmission FIFO  24   b  is a buffer that stores therein video (sound) data generated by the browser  20   b.    
     The time management unit  25  manages time T unique to the distribution management apparatus  2 . The time acquisition unit  26  performs time adjustment processing in conjunction with a time controller  56  in the communication terminal  5  described below. Specifically, the time acquisition unit  26  acquires time information (T) indicating time T in the distribution management apparatus  2  from the time management unit  25 , receives time information (t) indicating time t in the communication terminal  5  from the time controller  56  described below through the transmitter/receiver  31  and a transmitter/receiver  51 , and transmits the time information (t) and the time information (T) to the time controller  56 . 
     The channel adaptive controller  27  calculates reproduction delay time U based on transmission delay time information (D) described below and calculates operation conditions such as the frame rate and the data resolution of a convertor  10  in the encoder bridge unit  30 . This reproduction delay time U is time for delaying reproduction through the buffering of data until being reproduced. 
     The encoder bridge unit  30  performs processing such as data format conversion on the video (sound) data generated by the browser  20  and stored in the transmission FIFO  24 . The encoder bridge unit  30  distributes the video (sound) data the data format of which has been converted to the communication terminals (the communication terminal  5   f   1  and the communication terminal  5   f   3 ) as objects of distribution. The encoder bridge unit  30  will be described in more detail with reference to  FIG. 15  and  FIG. 16 .  FIG. 15  is a detailed diagram of the encoder bridge unit  30 .  FIG. 16  is a functional block diagram illustrating the functions of the convertor  10 . 
     As illustrated in  FIG. 15 , the encoder bridge unit  30  includes a generating/selecting unit  310 , a selecting unit  320 , and a plurality of converters  10   a ,  10   b  provided therebetween. Although the two converters  10   a ,  10   b  are illustrated here, any number of them may be provided. In the following, any convertor is represented as a “convertor  10 ”. 
     Further, as illustrated in  FIG. 16 , the convertor  10  includes a trimming unit  11 , a resizing unit  12 , a dividing unit  13 , and the encoding unit  19 . The trimming unit  11 , the resizing unit  12 , and the dividing unit  13  do not perform any processing on sound data. 
     The trimming unit  11  performs processing to cut out only part of a video (image). The resizing unit  12  changes the reduced scale of a video (image). The dividing unit  13 , as illustrated in  FIG. 5 , divides the web content acquired from the web server  8 . 
     The encoding unit  19  in  FIG. 16  described below encodes the pieces of video (sound) data generated by the browser  20 , thereby converting them so that video (sound) data can be distributed to the communication terminal  5  through the communication network  9 . When the video is not in motion (when there is no inter-frame update (change)), a skip frame (may be sometimes referred to as frame skip) is thereafter inserted until the video moves to save a band. When only sound data is generated, only encoding is performed. 
     The generating/selecting unit  310  generates a new convertor  10  and selects pieces of video (sound) data to be input to a convertor  10  that is already generated. Examples of the case when the generating/selecting unit  310  newly generates a converter  10  may include selecting the converter  10  that is already generated and generating a converter  10  capable of conversion responsive to the reproduction capability of video (sound) data in the communication terminal  5 . Examples of the case when the generating/selecting unit  310  selects video (sound) data to be input to the converter  10  may include, in stating the distribution to the communication terminal  5   f   3  in addition to the distribution to the communication terminal  5   f   1 , distributing the same video (sound) data as the video (sound) data being distributed to the communication terminal  5   f   1  to the communication terminal  5   f   3 . In such a case, furthermore, when the communication terminal  5   f   3  has the same reproduction capability as the reproduction capability of video (sound) data of the communication terminal  5   f   1 , the generating/selecting unit  310 , without generating a new convertor  10   b  for the communication terminal  5   f   3 , utilizes the convertor  10   a  that is already generated for the communication terminal  5   f   1 . 
     The selecting unit  320  selects a desired one from the converters  10  that are already generated. The selection by the generating/selecting unit  310  and the selecting unit  320  can perform distribution of various patterns as illustrated in  FIG. 6 . 
     Returning back to  FIG. 8 , the transmitter/receiver  31  transmits and receives various data, requests, and the like to and from the communication terminal  5 . For example, in the login processing of the communication terminal  5 , the transmitter/receiver  31  transmits, to the transmitter/receiver  51  described below of the communication terminal  5 , authentication screen data for prompting a user a login request. The transmitter/receiver  31  also performs data transmission and data reception to and from application programs (user applications or device applications) installed in the communication terminal  5  in order to receive the services of the distribution system  1  in accordance with a protocol unique to the distribution system  1  through a Hypertext Transfer Protocol over Secure Socket Layer (HTTPS) server. This unique protocol is an HTTPS-based application layer protocol for transmitting and receiving data in real time and without being interrupted between the distribution management apparatus  2  and the communication terminal  5 . The transmitter/receiver  31  also performs processing of transmission response control, real-time data generation, command transmission, reception response control, reception data analysis, and gesture conversion. 
     The transmission response control is processing to manage an HTTPS session for downloading requested from the communication terminal  5  in order to transmit data from the distribution management apparatus  2  to the communication terminal  5 . The response of the HTTPS session for downloading does not end immediately and holds for a certain period of time (one to a few minutes). The transmitter/receiver  31  dynamically writes data to be sent to the communication terminal  5  in the Body part of the response. In order to eliminate costs for reconnection, another request is allowed to reach from the communication terminal  5  before the previous session ends. By putting the transmitter/receiver  31  on standby until the previous request is completed, overhead can be eliminated even when reconnection is performed. 
     The real-time data generation is processing to add a unique header to the data (RTP data) of compressed video (and a compressed sound) generated by the encoding unit  19  in  FIG. 16  described later and write it in the Body part of a downstream HTTPS to the communication terminal  5 . 
     Client command transmission is processing to generate command data to be transmitted to the communication terminal  5  and write it in the Body part of HTTPS for distribution (downstream) to the communication terminal  5 . 
     The reception response control is processing to manage an HTTPS session requested from the communication terminal  5  in order for the distribution management apparatus  2  to receive data from the communication terminal  5 . The response of this HTTPS session does not end immediately and is held for a certain period of time (one to a few minutes). The communication terminal  5  dynamically writes data to be sent to the transmitter/receiver  31  of the distribution management apparatus  2  in the Body part of the request. 
     The reception data analysis is processing to analyze the data transmitted from the communication terminal  5  by type and deliver the data to a necessary process. 
     The gesture conversion is processing to convert a gesture event input to the communication terminal  5   f  as the electronic blackboard by a user with an electronic pen P or in handwriting into a format capable of being received by the browser  20 . 
     The reception FIFO  34  is a buffer that stores therein video (sound) data decoded by the decoding unit  40 . 
     The recognizing unit  35  performs processing on video (sound) data [E] received from the communication terminal  5 . Specifically, for example, the recognizing unit  35  recognizes the face, age, sex, and the like of men or animals based on videos taken by a camera  62  described below for signage. For offices, the recognizing unit  35  performs name tagging by face recognition and processing of replacing a background video based on videos taken by the camera  62  described below. The recognizing unit  35  stores recognition information  23 A indicating the recognized details in the storage unit  23 . The recognizing unit  35  achieves speeding up by performing processing with a recognition expansion board. 
     The delay information acquisition unit  37   a  corresponds to a delay information acquisition unit  57  used for the processing of upstream channel adaptive control (for the communication from the communication terminal  5  to the distribution management apparatus  2 ), and is used for the processing of downstream channel adaptive control (for the communication from the distribution management apparatus  2  to the communication terminal  5 ). Specifically, the delay information acquisition unit  37   a  acquires transmission delay time information (d1) indicating transmission delay time d1 from the decoding unit  40  and holds it for a certain period of time, and when a plurality of pieces of transmission delay time information (d1) are acquired, outputs to the channel adaptive controller  37   b  transmission delay time information (d) indicating frequency distribution information by a plurality of pieces of transmission delay time d1. 
     The channel adaptive controller  37   b  is used for the processing of the upstream channel adaptive control correspondingly to the channel adaptive controller  27  described above for use in the processing of the downstream channel adaptive control. Specifically, the channel adaptive controller  37   b  calculates the operation conditions of the encoding unit  60  based on the transmission delay time information (d). The channel adaptive controller  37   b  transmits a channel adaptive control signal indicating operation conditions such as a frame rate and data resolution to the encoding unit  60  of the communication terminal  5  through the transmitter/receiver  31  and the transmitter/receiver  51  described below. 
     The decoding unit  40  decodes the video (sound) data [E] transmitted from the communication terminal  5 . 
     Functional Configuration of Communication Terminal 
     Described next with reference to  FIG. 10  is the functional configuration of the communication terminal  5 .  FIG. 10  is a functional block diagram illustrating mainly the functions of the communication terminal  5 . Although  FIG. 10  illustrates the communication terminal  5   f   1  as an example of the communication terminal  5 , any communication terminal  5  other than the communication terminal  5   f   1  has similar functional components. Among the communication terminals  5 , any communication terminal  5  in which a user application is installed serves as an interface for allowing the user to perform a login to the distribution system  1 , start or stop the distribution of video (sound) data, and other operations. Any communication terminal  5  in which a device application is installed only transmits and receives video (sound) data and transmits operation information, without having the interface. The following describes the communication terminal  5  in which the user application is installed, for convenience. 
     The communication terminal  5  is provided with the functional components illustrated in  FIG. 10  by the same hardware configuration and program (user application) as those in  FIG. 7 . Specifically, the communication terminal  5  includes a decoding unit  50 , the transmitter/receiver  51 , an operating unit  52 , the reproduction controller  53 , a rendering unit  55 , a time controller  56 , the delay information acquisition unit  57 , a display unit  58 , and the encoding unit  60 . The communication terminal  5  further includes a storage unit  5000  constructed by the RAM  203  illustrated in  FIG. 7 . This storage unit  5000  stores therein time difference information (Δ) indicating a time difference Δ described below and time information (t) indicating time t in the communication terminal  5 . 
     The decoding unit  50  decodes video (sound) data [AEp] distributed from the distribution management apparatus  2  and output from the reproduction controller  53 . 
     The transmitter/receiver  51  transmits and receives various data, requests, and the like to and from the transmitter/receiver  31  of the distribution management apparatus  2  and a transmitter/receiver  71   a  of the terminal management apparatus  7  described below. For example, in the login processing of the communication terminal  5 , the transmitter/receiver  51  performs a login request to the transmitter/receiver  71  of the terminal management apparatus  7  based on the startup of the communication terminal  5  by the operating unit  52 . 
     The operating unit  52  performs processing to receive operation input by a user. For example, the operating unit  52  receives input, selection, or the like with a power switch, a keyboard, a mouse, the electronic pen P, or the like, and transmits it as operation information [p] to the browser management unit  22  of the distribution management apparatus  2 . 
     The reproduction controller  53  buffers the video (sound) data [AEp] (a packet of real-time data) received from the transmitter/receiver  51  and outputs it to the decoding unit  50  considering reproduction delay time U. 
     The rendering unit  55  renders the data decoded by the decoding unit  50 . 
     The time controller  56  performs time adjustment processing in conjunction with the time acquisition unit  26  of the distribution management apparatus  2 . Specifically, the time controller  56  acquires time information (t) indicating time t in the communication terminal  5  from the storage unit  5000 . The time controller  56  issues a request for time information (T) indicating time T in the distribution management apparatus  2  to the time acquisition unit  26  of the distribution management apparatus  2  through the transmitter/receiver  51  and the transmitter/receiver  31 . In this case, the time information (t) is transmitted concurrently with the request for the time information (T). 
     The delay information acquisition unit  57  acquires from the reproduction controller  53  transmission delay time information (D1) indicating transmission delay time D1 and holds it for a certain period of time, and when a plurality of pieces of transmission delay time information (D1) are acquired, outputs transmission delay time information (D) indicating frequency distribution information by a plurality of pieces of transmission delay time D1 to the channel adaptive controller  27  through the transmitter/receiver  51  and the transmitter/receiver  31 . The transmission delay time information (D) is transmitted, for example, once in a hundred frames. 
     The display unit  58  reproduces the data rendered by the rendering unit  55 . 
     The encoding unit  60  transmits video (sound) data [E] that is acquired from a built-in microphone  213  (refer to  FIG. 7 ) or the camera  62  and a microphone  63 , which are externally attached, and is encoded, time information (t 0 ) indicating the current time t 0  in the communication terminal  5  acquired from the storage unit  5000 , and the time difference information (Δ) indicating the time difference Δ acquired from the storage unit  5000  to the decoding unit  40  of the distribution management apparatus  2  through the transmitter/receiver  51  and the transmitter/receiver  31 . The operation conditions of the encoding unit  60  are changed based on the channel adaptive control signal received from the channel adaptive controller  37   b . When the operation conditions are changed, the encoding unit  60 , in accordance with the new operation conditions, transmits the video (sound) data [E] that is acquired from the camera  62  and the microphone  63  and is encoded, the time information (t 0 ) indicating the current time t 0  in the communication terminal  5  acquired from the storage unit  5000 , and the time difference information (Δ) indicating the time difference Δ acquired from the storage unit  5000  to the decoding unit  40  of the distribution management apparatus  2  through the transmitter/receiver  51  and the transmitter/receiver  31 . 
     The built-in microphone  213 , and the externally attached camera  62  and the microphone  63  are examples of an inputting unit and are devices that need encoding and decoding. The inputting unit may output touch data and smell data in addition to video (sound) data. The inputting unit includes various sensors such as a temperature sensor, a direction sensor, an acceleration sensor, and the like. 
       FIG. 10  illustrates an example in which a communication terminal  5   e  as a TV conference terminal is connected to the communication terminal  5   f   1  as the electronic blackboard. Specifically, illustrated is a case of the blackboard capable of receiving an operation path drawn by the user, and electronically converting the operation path. In the illustration, a camera and a microphone of the communication terminal  5   e  are used as the external camera  62  and microphone  63  of the communication terminal  5   f   1 .  FIG. 10  assumes a case in which the communication terminal  5   f   1  and the communication terminal  5   f   3  as the object of remote sharing processing are projectors that reproduce video (sound). 
     Functional Configuration of the Terminal Management Apparatus 
     Described next with reference to  FIG. 11  is the functional configuration of the terminal management apparatus  7 .  FIG. 11  is a functional block diagram illustrating the functions of the terminal management apparatus  7 . 
     The terminal management apparatus  7  achieves functional components illustrated in  FIG. 11  by similar hardware configuration and the programs to those in  FIG. 7 . Specifically, the terminal management apparatus  7  includes the transmitter/receiver  71   a , a transmitter/receiver  71   b , and an authentication unit  75 . The terminal management apparatus  7  further includes a storage unit  7000  constructed by the HDD  204  illustrated in  FIG. 7 . The storage unit  7000  stores therein distribution destination selection menu data, a terminal management table  7010 , and an available terminal management table  7020 . 
     The distribution destination selection menu is data indicating such a destination selection menu screen as illustrated in  FIG. 12 .  FIG. 12  is a conceptual diagram of a distribution destination selection menu screen. The distribution destination selection menu screen illustrated in  FIG. 12  displays shared IDs and display names (described below) in a list form for the communication terminal  5  that can be selected as a distribution destination of video (sound) data. The user checks the item representing the communication terminal  5  desired as a distribution destination of video (sound) data on this distribution destination selection menu screen and presses the “OK” button, whereby the video (sound) data is distributed to the desired communication terminal  5 . 
       FIG. 13  is a conceptual diagram of a terminal management table  7010 . As illustrated in  FIG. 13 , the terminal management table  7010  manages the terminal ID of the registered communication terminal  5 , a user certificate, contract information when a user uses the services of the distribution system  1 , the terminal type of the communication terminal  5 , setting information indicating the home uniform resource locators (URLs) of the respective communication terminals  5 , the execution environment information of the respective communication terminals  5 , a shared ID, an arrangement position, a linked URL, and display name information in association with each other. The information indicating arrangement position may be referred to as arrangement position information below. 
     The user certificate is a certificate that certifies that the communication terminal  5  is permitted to connect to the distribution system  1 . The user certificate is issued in advance to the communication terminal permitted to connect to the distribution system  1 . The contract information indicates the contents of a contract when a user who uses the communication terminal  5  identified by the terminal ID uses a service of the distribution system  1 . The terminal type indicates the type of the communication terminal  5 . The terminal ID, the setting information (home URL), and the destination URL are the same as those in the drawing table  23 C (refer to  FIG. 9 ). 
     The execution environment information includes “favorites”, “previous Cookie information”, and “cache file” of the respective communication terminals  5 , which are sent to the distribution management apparatus  2  together with the setting information after the login of each communication terminal  5  and are used for performing an individual service on each communication terminal  5 . 
     The shared ID is an ID that is used when each user distributes the same video (sound) data as video (sound) data being distributed to his/her own communication terminal  5  to the other communication terminals  5 , thereby performing remote sharing processing and is identification information that identifies the other communication terminals and the other communication terminal group. In the example illustrated in  FIG. 13 , the shared ID of the terminal ID “t006” is “v006”, and the shared ID of the terminal ID “t007” is “v006”. In this case, when a request for remote sharing processing with the communication terminals  5   f   1 ,  5   f   3  with the shared ID “v006” is issued from the communication terminal  5   a  with the terminal ID “t001”, the distribution management apparatus  2  distributes the same video (sound) data as video (sound) data being distributed to the communication terminals  5   a  to the communication terminals  5   f   1 ,  5   f   3 . However, when the communication terminals  5  and the communication terminals  5   f   1 ,  5   f   2  are different in the resolution of the display unit  58 , the distribution management apparatus  2  distributes the video (sound) data accordingly. 
     As illustrated in  FIG. 5 , for example, the arrangement position indicates an installation position when the communication terminals  5   f   1 ,  5   f   2 ,  5   f   3  are arranged side by side. The display name is information indicating the details of the display name in the distribution destination selection menu illustrated in  FIG. 12 . 
       FIG. 14  is a conceptual diagram of an available terminal management table  7020 . The available terminal management table  7020  manages, in association with each terminal ID, a shared ID indicating another communication terminal or another communication terminal group with which the communication terminal  5  indicated by the terminal ID can perform remote sharing processing. 
     Returning back to  FIG. 11 , the storage unit  7000  stores therein user information required for the services of the distribution system  1  and permanent data such as device information. The storage unit  7000  stores therein various kinds of information used for the management of the distribution system  1  such as distribution information indicating the state (disconnected state/standby state/busy) of the communication terminal  5  and load information indicating the load state of the distribution management apparatus  2 . 
     The storage unit  7000  may be stored in an external storage device and may be configured to be separated from the distribution management apparatus  7 . In this case, the storage unit  7000  may be connected to the distribution management apparatus  7  with Transmission Control Protocol/Internet Protocol (TCP/IP), for example. 
     The transmitter/receiver  71   a  transmits and receives various data, requests, and the like to and from the communication terminal  5 . For example, the transmitter/receiver  71   a  receives a login request from the transmitter/receiver  51  of the communication terminal  5  and transmits an authentication result of the login request to the transmitter/receiver  51 . The login request is an authentication request for the communication terminal  5  to the distribution system  1 . The login request includes a terminal ID that uniquely identifies the communication terminal  5  and the user certificate. 
     The transmitter/receiver  71   b  transmits and receives various data, requests, and the like to and from the distribution management apparatus  2 . For example, the transmitter/receiver  71   b  receives a request for the data of the distribution destination selection menu from the transmitter/receiver  21  of the distribution management apparatus  2  and transmits the data of the distribution destination selection menu to the transmitter/receiver  21 . 
     The authentication unit  75  searches the terminal management table  7010  based on the terminal ID and the user certificate in the login request received from the communication terminal  5 , thereby determining whether there are any terminal ID and user certificate of the same combination, thereby authenticating the communication terminal  5   a.    
     Operations or Processing of the Embodiment 
     Described next with reference to  FIG. 17  to  FIG. 25  are operations or pieces of processing of the present embodiment. 
     Basic Distribution Processing 
     Described first with reference to  FIG. 17  is specific distribution processing in a basic distribution method of the distribution management apparatus  2 .  FIG. 17  is a sequence diagram illustrating the basic distribution processing of the distribution management apparatus  2 . Although a case is described in which a login is requested through the communication terminal  5   a , the login may be performed through the communication terminal  5  other than the communication terminal  5   a.    
     As illustrated in  FIG. 17 , when a user turns on the power of the communication terminal  5   a , the transmitter/receiver  51  of the communication terminal  5   a  issues a login request to the authentication unit  75  through the transmitter/receiver  71   a  of the terminal management apparatus  7  (Step S 21 ). This login request includes the terminal ID and the user certificate of the communication terminal  5   a.    
     The authentication unit  75  of the terminal management apparatus  7  searches the terminal management table  7010  based on the terminal ID and the user certificate received from the communication terminal  5   a , thereby determining whether there are any terminal ID and user certificate of the same combination, thereby authenticating the communication terminal  5   a  (Step S 22 ). Described below continuously is a case when the terminal ID and the user certificate of the same combination are present in the terminal management table  7010 , that is, when the communication terminal  5   a  is determined as a proper terminal in the distribution system  1 . 
     The authentication unit  75  of the terminal management apparatus  7  transmits the IP address of the distribution management apparatus  2  to the transmitter/receiver  51  of the communication terminal  5   a  through the transmitter/receiver  71   a  (Step S 23 ). The IP address of the distribution management apparatus  2  is acquired by the terminal management apparatus  7  and is stored in the storage unit  7000  in advance. 
     The transmitter/receiver  71   b  of the terminal management apparatus  7  issues a browser  20  startup request to the browser management unit  22  through the transmitter/receiver  21  of the distribution management apparatus  2  (Step S 24 ). In response to this startup request, the browser management unit  22  of the distribution management apparatus  2  starts up the browser  20  (Step S 25 ). The generating/selecting unit  310  of the encoder bridge unit  30  generates the convertor  10  in accordance with the reproduction capability of the communication terminal  5   a  (the resolution of the display and the like) and the type of content (Step S 26 ). 
     Next, the browser  20  issues a request for content data [A] to the web server  8  (Step S 27 ). In response thereto, the web server  8  reads the requested content data [A] from its own storage unit (not illustrated) (Step S 28 ). The web server  8  transmits the content data [A] to the browser  20  that is a request source through the transmitter/receiver  21  of the distribution management apparatus  2  (Step S 29 ). 
     The browser  20  renders the content data [A] to generate video (sound) data [A] and transmits it to the transmission FIFO  24  (Step S 30 ). The convertor  10  encodes the pieces of image (sound) data [A] stored in the transmission FIFO  24 , thereby converting them into video (sound) data [A] to be output to the communication terminal  5   a  (Step S 31 ). 
     The encoder bridge unit  30  transmits the video (sound) data [A] to the reproduction controller  53  through the transmitter/receiver  31  and the transmitter/receiver  51  (Step S 32 ). In response to this, the communication terminal  5   a  outputs the video (sound) data [A] from the reproduction controller  53  to the decoding unit  50 , thereby reproducing sound from a speaker  61  and reproducing video on the display unit  58  through the rendering unit  55  (Step S 33 ). 
     Processing of Time Adjustment 
     Described next with reference to  FIG. 18  is the processing of time adjustment.  FIG. 18  is a sequence diagram illustrating the processing of time adjustment performed between the distribution management apparatus  2  and the communication terminal  5 . 
     In order to acquire time indicating a point in time when the transmitter/receiver  51  issues a request for the time information (T) to the distribution management apparatus  2 , the time controller  56  of the communication terminal  5  acquires time information (t s ) in the communication terminal  5  from the storage unit  5000  (Step S 81 ). The transmitter/receiver  51  issues a request for the time information (T) in the distribution management apparatus  2  to the transmitter/receiver  31  (Step S 82 ). In this case, the time information (t s ) is transmitted concurrently with the request for the time information (T). 
     In order to acquire time indicating a point in time when the transmitter/receiver  31  received the request at Step S 82 , the time acquisition unit  26  acquires time information (T r ) in the distribution management apparatus  2  from the time management unit  25  (Step S 83 ). In order to acquire time indicating a point in time when the transmitter/receiver  31  responds to the request at Step S 82 , the time acquisition unit  26  further acquires time information (T s ) in the distribution management apparatus  2  from the time management unit  25  (Step S 84 ). The transmitter/receiver  31  then transmits the time information (t s , T r , T s ) to the transmitter/receiver  51  (Step S 85 ). 
     In order to acquire time indicating a point in time when the transmitter/receiver  51  received the response at Step S 85 , the time controller  56  of the communication terminal  5  acquires time information (t r ) in the communication terminal  5  from the storage unit  5000  (Step S 86 ). The time controller  56  of the communication terminal  5  calculates the time difference Δ between the distribution management apparatus  2  and the communication terminal  5  (Step S 87 ). This time difference Δ is represented by Equation (1) below. 
       Δ=(( T   r   +T   s )/2)−(( t   r   +t   s )/2)  (1)
 
     The time controller  56  stores the time difference information (Δ) indicating the time difference Δ in the storage unit  5000  (Step S 88 ). The series of processing of time adjustment is performed, for example, regularly every minute. 
     Processing of Downstream Channel Adaptive Control 
     Described next with reference to  FIG. 19  is the processing of channel adaptive control on data transmitted from the distribution management apparatus  2  to the communication terminal  5  (downstream).  FIG. 19  is a sequence diagram illustrating the processing of channel adaptive control on data transmitted from the distribution management apparatus  2  to the communication terminal  5 . 
     First, the encoder bridge unit  30  of the distribution management apparatus  2  transmits reproduction delay time information (U) for buffering to delay the reproduction to the reproduction controller  53  of the communication terminal  5  through the transmitter/receiver  31  and the transmitter/receiver  51  (Step S 101 ). The encoder bridge unit  30  adds the current time T 0  as a time stamp acquired from the time management unit  25  to the video (sound) data acquired from the transmission FIFO  24  and subjected to encoding or other operations, and transmits them to the reproduction controller  53  of the communication terminal  5  through the transmitter/receiver  31  and the transmitter/receiver  51  (Step S 102 ). 
     In the communication terminal  5 , the reproduction controller  53  waits until the time (T 0 +U−Δ) in the communication terminal  5  and then outputs the video (sound) data to the decoding unit  50 , thereby causing the speaker  61  to reproduce sound and the display unit  58  to reproduce video through the rendering unit  55  (Step S 103 ). This causes only video (sound) data the communication terminal  5  received within the range of the reproduction delay time U represented by Equation (2) below to be reproduced, while video (sound) data out of the range is deleted without being reproduced. 
         U ≧( t   0 +Δ)− T   0   (2)
 
     The reproduction controller  53  reads the current time t 0  in the communication terminal  5  from the storage unit  5000  (Step S 104 ). This time t 0  indicates time in the communication terminal  5  at a point in time when the communication terminal  5  received video (sound) data from the distribution management apparatus  2 . The reproduction controller  53  further reads the time difference information (Δ) indicating the time difference Δ stored at Step S 86  from the storage unit  5000  (Step S 105 ). The reproduction controller  53  then calculates transmission delay time D1 indicating time from when the video (sound) data is transmitted from the distribution management apparatus  2  to when the communication terminal  5  receives the video (sound) data using the time T 0 , the time t 0 , and the time difference Δ (Step S 106 ). This calculation is performed by Equation (3) below; when the communication network  9  becomes congested, the transmission delay time D1 becomes longer. 
         D 1=( t   0 +Δ)− T   0   (3)
 
     The delay information acquisition unit  57  acquires transmission delay time information (D1) indicating the transmission delay time D1 from the reproduction controller  53  and holds it for a certain time, and when a plurality of pieces of transmission delay time information (D1) are acquired, transmits transmission delay time information (D) indicating frequency distribution information on a plurality of pieces of transmission delay time D1 to the channel adaptive controller  27  of the distribution management apparatus  2  through the through the transmitter/receiver  31  and the transmitter/receiver  51  (Step S 107 ). 
     The channel adaptive controller  27  of the distribution management apparatus  2  newly calculates reproduction delay information U′ based on the transmission delay time information (D) and calculates the operation conditions such as the frame rate and the data resolution of the convertor  10  (Step S 108 ). 
     The encoder bridge unit  30  of the distribution management apparatus  2  transmits reproduction delay time information (U′) indicating the new reproduction delay time U′ calculated at Step S 108  to the reproduction controller  53  of the communication terminal  5  through the transmitter/receiver  31  and the transmitter/receiver  51  (Step S 109 ). 
     The convertor  10  of the encoder bridge unit  30  further changes the operation conditions based on the channel adaptive control signal (Step S 110 ). For example, when the transmission delay time D1 is too long, when the reproduction delay time U is made longer in accordance with the transmission delay time D1, reproduction time at the speaker  61  and the display unit  58  becomes too delayed. As a result, there is a limit to making the reproduction delay time U longer. In view of this, the channel adaptive controller  27  not only causes the encoder bridge unit  30  to change the reproduction delay time U to be the reproduction delay time U′ but also causes the convertor  10  to decrease the frame rate of video (sound) data and to decrease the resolution of video (sound) data, thereby addressing the congestion of the communication network  9 . In response to this, the encoder bridge unit  30  transmits the video (sound) data with the current time T 0  added as a time stamp to the reproduction controller  53  of the communication terminal  5  in accordance with the changed operation conditions as Step S 102  (Step S 111 ). 
     In the communication terminal  5 , reproduction delay time information (U′) the reproduction controller  53  waits until the time (T 0 +U′−Δ) in the communication terminal  5  and then outputs the video (sound) data received within the reproduction delay time (U′) to the decoding unit  50 , thereby, as with Step S 103 , causing the speaker  61  to output a sound and the display unit  58  to reproduce video through the rendering unit  55  (Step S 112 ). After that, the processing at and after Step S 104  is performed continuously. Thus, the processing of the downstream channel adaptive control is performed continuously. 
     Processing of Upstream Channel Adaptive Control 
     Described next with reference to  FIG. 20  is the processing of channel adaptive control on data transmitted from the communication terminal  5  to the distribution management apparatus  2  (upstream).  FIG. 20  is a sequence diagram illustrating the processing of channel adaptive control on data transmitted from the communication terminal  5  to the distribution management apparatus  2 . 
     First the encoding unit  60  of the communication terminal  5  encodes video and sound acquired from the camera  62  and the microphone  63  in video (sound) data [E], thereafter, transmits the video (sound) data [E], the time information (t 0 ) indicating the current time t 0  in the communication terminal  5  acquired from the storage unit  5000 , and the time difference information (Δ) indicating the time difference Δ acquired from the storage unit  5000  to the decoding unit  40  of the distribution management apparatus  2  through the transmitter/receiver  31  and the transmitter/receiver  51  (Step S 121 ). 
     In the distribution management apparatus  2 , the decoding unit  40  reads time T 0  indicating a point in time when the video (sound) data [E] and the like were received at Step S 121  from the time management unit  25  (Step S 122 ). The decoding unit  40  then calculates transmission delay time d1 indicating time from when the video (sound) data is transmitted from the communication terminal  5  to when it is received by the distribution management apparatus  2  (Step S 123 ). This calculation is performed by Equation (4) below; when the communication network  9  becomes congested, the transmission delay time D1 becomes longer. 
         d 1 =T   0 −( t   0 +Δ)  (4)
 
     As is the case with the delay information acquisition unit  57  of the communication terminal  5 , the delay information acquisition unit  37   a  of the distribution management apparatus  2  acquires transmission delay time information (d1) indicating transmission delay time d1 from the decoding unit  40  and holds it for a certain period of time, and when a plurality of pieces of transmission delay time information (d1) are acquired, outputs to the channel adaptive controller  37   b  transmission delay time information (d) indicating frequency distribution information by a plurality of pieces of transmission delay time d1 (Step S 124 ). 
     The channel adaptive controller  37   b  calculates the operation conditions of the encoding unit  60  of the communication terminal  5  based on the transmission delay time information (d) (Step S 125 ). The channel adaptive controller  37   b  transmits the channel adaptive control signal indicating operation conditions such as a frame rate and data resolution to the encoding unit  60  of the communication terminal  5  through the transmitter/receiver  31  and the transmitter/receiver  51  (Step S 126 ). In other words, the channel adaptive controller  27  for the downstream case outputs the channel adaptive control signal to the encoder bridge unit  30  within the same distribution management apparatus  2 , whereas the channel adaptive controller  37   b  for the upstream case outputs the channel adaptive control signal from the distribution management apparatus  2  to the communication terminal  5  through the communication network  9 . 
     The encoding unit  60  of the communication terminal  5  changes the operation conditions based on the received channel adaptive control signal (Step S 127 ). The encoding unit  60 , based on the new operation conditions, encodes video and sound acquired from the camera  62  and the microphone  63  in the video (sound) data [E], thereafter, transmits the video (sound) data [E], the time information (t 0 ) indicating the current time t 0  in the communication terminal  5  acquired from the storage unit  5000 , and the time difference information (Δ) indicating the time difference Δ similarly acquired from the storage unit  5000  to the decoding unit  40  of the distribution management apparatus  2  through the transmitter/receiver  31  and the transmitter/receiver  51 , as Step S 121  (Step S 128 ). After that, the processing at and after Step S 122  is performed continuously. Thus, the processing of the upstream channel adaptive control is performed continuously. 
     Processing of Multidisplay 
     Described next with reference to  FIG. 21  to  FIG. 23  is the processing of multidisplay.  FIG. 21  to  FIG. 23  are sequence diagrams illustrating the processing of multidisplay illustrated in  FIG. 5 . Described here is an example of reproducing video (sound) [XYZ] being reproduced on the communication terminal  5   a  also on the communication terminals ( 5   f   1 ,  5   f   2 ,  5   f   3 ) in a divided manner. 
     The browser  20  for displaying web content is represented as a “browser  20   a ”, and the browser  20  for displaying a setting screen for a user is represented as a “browser  20   b ”. Described first is processing corresponding to Step S 30  in  FIG. 17 . 
     First, as illustrated in  FIG. 21 , the browser  20   a  of the distribution management apparatus  2  renders web content data [XYZ] acquired from the web server  8  to generate image (sound) data and outputs it to the transmission FIFO  24  (Step S 201 ). The converter  10  of the encoder bridge unit  30  encodes the image (sound) data stored in the transmission FIFO  24 , thereby converting it into video (sound) data [XYZ] to be distributed to the communication terminal  5   a  (Step S 202 ). 
     The encoder bridge unit  30  transmits the video (sound) data [XYZ] to the reproduction controller  53  of the communication terminal  5   a  through the transmitter/receiver  31  and the transmitter/receiver  51  (Step S 203 ). In response to this, the communication terminal  5   a  outputs the video (sound) data [XYZ] from the reproduction controller  53  to the decoding unit  50 , thereby reproducing video (sound) on the display unit  58  through the rendering unit  55  (Step S 204 ). 
     A screen displayed on the display unit  58  is switched to a menu request screen (not illustrated) by the user of the communication terminal  5   a , and the operating unit  52  receives the pressing of a “distribution destination selection menu” (not illustrated) on the menu request screen (Step S 205 ). This causes the transmitter/receiver  51  to request for switching to the distribution destination selection menu to the transmitter/receiver  71   a  of the terminal management apparatus  7  (Step S 206 ). In this situation, the terminal ID of the communication terminal  5   a  is also transmitted. In response thereto, the transmitter/receiver  71   b  issues a browser  20   b  startup request to the browser management unit  22  of the distribution management apparatus  2  through the transmitter/receiver  21  (Step S 207 ). 
     The generating/selecting unit  310  of the encoder bridge unit  30  starts up the browser  20   b  (Step S 208 ) and switches the output from the browser  20   a  to the convertor  10  (e.g., the convertor  10   a ) to the output from the browser  20   b  to the convertor  10  (e.g., the convertor  10   b ) (Step S 209 ). When the communication terminal  5   a  and another communication terminal  5  (e.g., the communication terminal  5   b ) are receiving the video (sound) data at Step S 203  with the convertor  10  (e.g., the convertor  10   a ) shared, the generating/selecting unit  310  of the encoder bridge unit  30  newly generates the convertor  10  (e.g., the convertor  10   b ), because the other communication terminal  5  (e.g., the communication terminal  5   b ) is using the convertor  10  (e.g., the convertor  10   a ) for the browser  20   a.    
     The browser  20   b  requests a distribution destination selection menu from the storage unit  7000  of the distribution management apparatus  7  through the transmitter/receiver  21  and the transmitter/receiver  71   b  (Step S 210 ). In response thereto, the storage unit  7000  of the distribution management apparatus  7  searches the available terminal management table  7020  stored in the storage unit  7000  based on the terminal ID received from the communication terminal  5   a , thereby extracting a shared ID (Step S 211 ). This shared ID indicates a communication terminal  5  available by the communication terminal  5   a  to perform the remote sharing processing. When the terminal ID of the communication terminal  5   a  is “t001”, for example, the available terminal management table  7020  illustrated in  FIG. 14  is searched, thereby extracting shared IDs “v003” and “v006”. 
     The storage unit  7000  further searches the terminal management table  7010  based on the extracted shared ID, thereby extracting display name information indicating the corresponding display name (Step S 212 ). As illustrated in  FIG. 13 , display names corresponding to the extracted shared IDs “v003” and “v006” are “Tokyo head office 10F MFP” and “Osaka exhibition hall 1F multiprojector”, respectively. 
     The storage unit  7000  transmits the data of the distribution destination selection menu as content data to the browser  20   b  of the distribution management apparatus  2  through the transmitter/receiver  71   b  and the transmitter/receiver  21  (Step S 213 ). This distribution destination selection menu includes the check boxes, shared IDs, and display names as illustrated in  FIG. 12 . 
     As illustrated in  FIG. 22 , the browser  20   b  of the distribution management apparatus  2  renders content data indicating a distribution destination selection menu [M] acquired from the distribution management apparatus  7  to generate image (sound) data and outputs it to the transmission FIFO  24  (Step S 221 ). The converter  10  of the encoder bridge unit  30  encodes the image (sound) data [M] stored in the transmission FIFO  24 , thereby converting into video (sound) data [M] to be distributed to the communication terminal  5   a  (Step S 222 ). 
     The encoder bridge unit  30  then transmits the video (sound) data [M] to the reproduction controller  53  of the communication terminal  5   a  through the transmitter/receiver  31  and the transmitter/receiver  51  (Step S 223 ). In response to this, the communication terminal  5   a  outputs the video (sound) data [M] from the reproduction controller  53  to the decoding unit  50 , thereby reproducing the video (sound) of the distribution destination selection menu as illustrated in  FIG. 12  on the display unit  58  through the rendering unit  55  (Step S 224 ). 
     When an operation to designate the communication terminal  5  to be used for multidisplay, for example, the check box of the shared ID “v006” of the distribution destination selection menu screen illustrated in  FIG. 12  is checked and the “OK” button is pressed (Step S 225 ) by the user, the operating unit  52  transmits the result of the check operation to the browser management unit  22  of the distribution management apparatus  2  through the transmitter/receiver  51  and the transmitter/receiver  31  (Step S 226 ). 
     The browser  20   b  of the distribution management apparatus  2  selects a shared ID from the result of the check operation (Step S 227 ). The browser  20   b  issues a request for adding a distribution destination to the storage unit  7000  of the distribution management apparatus  7  through the transmitter/receiver  21  and the transmitter/receiver  71   b  (Step S 228 ). This request for adding a distribution destination includes the shared ID selected at Step S 227 . The browser  20   b  then ends its role to end (Step S 229 ). After that, the generating/selecting unit  310  of the encoder bridge unit  30  switches the output from the browser  20   b  to the converter  10  to the output from the browser  20   a  to the converter  10  (Step S 230 ). 
     As illustrated in  FIG. 23 , in the storage unit  7000  of the terminal management apparatus  7 , the terminal management table  7010  is searched based on the shared ID sent through Step S 228 , thereby extracting the corresponding terminal ID and arrangement position information (Step S 241 ). The storage unit  7000  performs issues an instruction to add a distribution destination to the browser management unit  22  of the distribution management apparatus  2  through the transmitter/receiver  71   b  and the transmitter/receiver  21  (Step S 242 ). This instruction to add a distribution destination includes the terminal ID and the arrangement position information extracted at Step S 241 . Included here are three sets of the terminal ID and the arrangement position information, that is, the terminal ID and the arrangement position information are “t006” and “left”, respectively, the terminal ID and the arrangement position information are “t007” and “middle”, respectively, and the terminal ID and the arrangement position information are “t008” and “right”, respectively. The communication terminals  5  identified by the terminal IDs “t006”, “t007”, and “t008” are the communication terminal  5   f   1 , the communication terminal  5   f   2 , and the communication terminal  5   f   3 , respectively. 
     The generating/selecting unit  310  of the encoder bridge unit  30  generates a convertor  10  for multidisplay (Step S 243 ). In this case, the generating/selecting unit  310  of the encoder bridge unit  30  acquires the terminal ID and the arrangement position information from the browser management unit  22 . The dividing unit  13  of the convertor  10  generated at Step S 243  divides the pieces of video (sound) data [XYZ] stored in the transmission FIFO  24 , and the encoding unit  19  encodes the divided pieces of data (Step S 244 ). 
     The encoder bridge unit  30  transmits the video (sound) data [X] to the reproduction controller  53  of the communication terminal  5   f   1  through the transmitter/receiver  31  and the transmitter/receiver  51  of the communication terminal  5   f   1  based on the terminal ID (“t006”) and the arrangement position information (“left”) (Step S 245 - 1 ). In response to this, the communication terminal  5   f   1  outputs the video (sound) data [X] from the reproduction controller  53  to the decoding unit  50 , thereby reproducing sound from the speaker  61 , and reproducing video on the display unit  58  through the rendering unit  55  (Step S 246 - 1 ). 
     Similarly, the encoder bridge unit  30  transmits the video (sound) data [Y] to the reproduction controller  53  of the communication terminal  5   f   2  through the transmitter/receiver  31  and the transmitter/receiver  51  of the communication terminal  5   f   2  based on the terminal ID (“t007”) and the arrangement position information (“middle”) (Step S 245 - 2 ). In response to this, the communication terminal  5   f   2  outputs the video (sound) data [Y] from the reproduction controller  53  to the decoding unit  50 , thereby reproducing sound from the speaker  61 , and reproducing video on the display unit  58  through the rendering unit  55  (Step S 246 - 2 ). 
     Similarly, the encoder bridge unit  30  transmits the video (sound) data [Z] to the reproduction controller  53  of the communication terminal  5   f   3  through the transmitter/receiver  31  and the transmitter/receiver  51  of the communication terminal  5   f   3  based on the terminal ID (“t008”) and the arrangement position information (“right”) (Step S 245 - 3 ). In response to this, the communication terminal  5   f   3  outputs the video (sound) data [Z] from the reproduction controller  53  to the decoding unit  50 , thereby reproducing sound from the speaker  61 , and reproducing video on the display unit  58  through the rendering unit  55  (Step S 246 - 3 ). 
     Processing of Communication with a Plurality of Communication Terminals 
     Described next with reference to  FIG. 24  is remote sharing processing with the distribution management apparatus  2 .  FIG. 24  is a sequence diagram illustrating the remote sharing processing with the distribution management apparatus  2 . Described here is specific processing for the pattern illustrated in  FIG. 8  assuming the communication terminals  5   f   1 ,  5   f   3  as the communication terminals. 
       FIG. 8  and  FIG. 24  assume that the communication terminal  5   f   1  (a first communication terminal) is an electronic blackboard that can receive operation paths drawn by a user and electronically convert the operation paths. It is also assumed that the other communication terminal as an object of the remote sharing processing with the communication terminals  5   f   1  is the communication terminals  5   f   3  (a second communication terminal) and that the communication terminal  5   f   3  is a projector that reproduces video (sound). 
     Although login processing, browser startup, and other operations similar to Step S 21  to Step S 29  in  FIG. 17  are performed also here, the description of the processing corresponding to Step S 21  to Step S 28  in  FIG. 17  are omitted, and described first is processing at Step S 41  corresponding to Step S 29 . 
     As illustrated in  FIG. 24 , the browser  20   b  of the distribution management apparatus  2  receives content data [B] from the web server  8   b  through the transmitter/receiver  21  (Step S 41 ). The browser  20   b  renders the content data [B], thereby generating video (sound) data, and outputs it to the transmission FIFO  24   b  (Step S 42 ). 
     The converter  10  of the encoder bridge unit  30  converts the data format of the video (sound) data [B] stored in the transmission FIFO  24   b  into a data format allowing the video (sound) data [B] to be distributed to the communication terminal  5   f   3  (Step S 43 ). The distribution management apparatus  2  transmits the converted video (sound) data [B] to the communication terminal  5   f   3  (Step S 44 ). 
     The converted video (sound) data ([B]) is decoded by the decoding unit  50  of the communication terminal  5   f   3  to be output as sound from the speaker  61 , or is rendered by the rendering unit  55  to be output as video to the display unit  58  (Step S 45 ). 
     The browser  20   a  of the distribution management apparatus  2  receives content data [A] from the web server  8   a  through the transmitter/receiver  21  (Step S 46 ). The browser  20   a  renders the content data [A], thereby generating video (sound) data, and outputs it to the transmission FIFO  24   a  (Step S 47 ). 
     It is assumed that the encoding unit  60  of the communication terminal  5   f   1  has received the inputting of content data [E] from the camera  62  and the microphone  63 . In this case, the encoding unit  60  of the communication terminal  5   f   1  encodes the content data [E] and then transmits it to the decoding unit  40  of the distribution management apparatus  2  through the transmitter/receiver  51  and the transmitter/receiver  31  (Step S 48 ). 
     The content data [E] received by the distribution management apparatus  2  is decoded by the decoding unit  40  and is then output to the browser  20   a  through the reception FIFO  34 . The browser  20   a  renders the content data [E], thereby generating image (sound) data [E], and outputs it to the transmission FIFO  24   a  (Step S 49 ). In this case, the browser  20   a  outputs the content data [E] combined with the content data [A] having been acquired. 
     The operating unit  52  of the communication terminal  5   f   1  receives operation by the user with the electronic pen P 1  or the like (Step S 50 ). The operating unit  52  transmits operation information [p] to the browser management unit  22  through the transmitter/receiver  51  and the transmitter/receiver  31  (Step S 51 ). In this manner, the operation information [p] is input to browser  20   a  of the browser management unit  22  of the distribution management apparatus  2 . In the browser  20   a , the acquiring unit  201  acquires the operation information [p]. 
     Next, the browser  20   a  performs drawing processing (Step S 53 ). 
       FIG. 25  is a flowchart illustrating the drawing processing. The browser  20   a  determines whether to perform the drawing processing (Step S 60 ). The browser  20   a  makes determination whether the processing contents instructed by the instruction information included in the operation information [p] acquired at Step S 51  (refer to  FIG. 24 ) is a drawing processing instruction, as the determination at Step S 60 . 
     When performing the drawing processing (Yes at Step S 60 ), the browser  20   a  performs mode determination (Step S 61 ). The browser  20   a  makes determination whether the mode indicated by the instruction information included in the operation information [p] acquired at Step S 51  (refer to  FIG. 24 ) is a drawing mode, as the determination at Step S 61 . 
     If the mode is the drawing mode (Yes at Step S 61 ), the browser  20   a  reads the path information included in the operation information [p] acquired at Step S 51  (refer to  FIG. 24 ) (Step S 62 ). By the processing at Step S 62 , the browser  20   a  reads the path attribute information such as the line type of an operation path, the thickness of the path, and the color of the path and a set of position coordinates indicating the path. When the operation path indicates a “point”, the set of position coordinates indicating paths may be one pair of position coordinates. 
     The browser  20   a  generates a path image (Step S 63 ). Specifically, the browser  20   a  renders the set of position coordinates indicating the path indicated by the path information included in the operation information [p] and the path attribute information, thereby generating a path image p as a command indicating a drawing instruction of an image indicating the operation path. The browser  20   a  generates the coordinates of the drawing starting position of the operation path from the set of position coordinates indicating the path included in the operation information [p] as coordinates on a page. In this manner, the browser  20   a  generates the path information (refer to  FIG. 9 ) including the path image p and the coordinates on the page. 
     The browser  20   a  stores the generated path information in the drawing table  23 C (Step S 64 ). In this situation, the browser  20   a  stores the terminal ID included in the operation information [p] received at Step S 51  (refer to  FIG. 24 ) and the home URL (setting information) of the communication terminal  5   f   1  identified by the terminal ID in association with the path information in the drawing table  23 C. 
     The browser  20   a  adds the generated path image p to a drawing layer (Step S 65 ). 
     In the present embodiment, video data generated by the browser  20  employs a layered structure. The present embodiment assumes a layered structure in which a background image layer, output image layer, a drawing layer, and a button layer are stacked in order. The order of stacking is not limited to this order. The background image layer is a layer that arranges thereon a background image such as grid lines. The output image layer is a layer that arranges thereon video data generated by the browser  20  from content data acquired from the web server  8  or other facilities. The drawing layer is a layer that arranges thereon the path image. The button layer is a layer that arranges thereon a button image for the user to input various kinds of instructions. 
     The browser  20   a  generates differential drawing (Step S 66 ). At the processing at Step S 65 , when the path image is already drawn on the drawing layer, the browser  20   a  adds the generated path image p to the drawing layer. The browser  20   a  then stores the differential drawing generated at Step S 66  in the storage unit  23  (Step S 67 ). 
     The browser  20   a  calls up identification information for identifying video (sound) data being reproduced in another communication terminal (the communication terminal  5   f   3  in the present embodiment) as an object of the remote sharing processing at the drawing timing included in the operation information [p] acquired from the communication terminal  5   f   1  at Step S 51  (refer to  FIG. 24 ) (Step S 68 ). This Step S 68  corresponds to Step S 52  in  FIG. 24 . 
     The browser  20   a  transmits an acquisition request for the identification information to the browser  20   b . The acquisition request includes the drawing timing. Upon receiving the acquisition request, the browser  20   b  identifies content data corresponding to the video (sound) data being distributed to the communication terminal  5   f   3  from the transmission FIFO  24   b  at the drawing timing included in the acquisition request. The browser  20   b  transmits identification information for identifying the identified content data to the browser  20   a  (refer to Step S 52  in  FIG. 24 ). 
     As described above, this identification information includes the destination URL indicating the URL of the browser  20  to which the content data is distributed and the destination URL terminal ID. 
     By receiving the identification information from the browser  20   b , the browser  20   a  acquires the identification information (Step S 69 ). The browser  20   a  then stores the acquired identification information and the path information generated at Step S 63  in association with each other in the drawing table  23 C (Step S 70 ). 
     By the processing at Step S 70 , for example, the terminal ID (“t006”), the setting information (“www.ricoh.co.jp”), the path information (the coordinates on the page “x1, y2” and the “wavy, blue, thick path image”), the identification information (the destination URL “http:www.skydrive.com”, and the destination URL terminal ID “t007”) in association with each other are stored in the drawing table  23 C, as illustrated in  FIG. 9 . 
     Although a case in which the path information stored in the drawing table  23 C includes the coordinates on the page and the path image is described in the present embodiment, all pieces of path information (the set of position coordinates indicating the path and the path attribute information) included in the operation information [p] received from the communication terminal  5  (the communication terminal  5   f   1  in the present embodiment) may be stored. 
     Returning back to  FIG. 25 , the browser  20   a  stacks the background image layer, the output image layer to which the content data ([A], [E]) having been acquired is added, the drawing layer to which the path image p is added, and the button layer separately prepared, thereby combining these video (sound) data and the path image p (Step S 71 ). The present routine then ends. 
     At Step S 61 , if the mode indicated by the instruction information included in the operation information [p] acquired at Step S 51  (refer to  FIG. 24 ) is an erase mode, negative determination is performed (No at Step S 61 ). The browser  20   a  selects a path image matching the position information on the screen of the operation path to be erased included in the operation information [p] from the drawing table  23 C (Step S 72 ). 
     The browser  20   a  erases the selected path image from the drawing layer (Step S 73 ). The browser  20   a  deletes the row including the selected path image from the drawing table  23 C (Step S 74 ). In other words, the selected path image, the terminal ID, the setting information, the coordinates on the page, and the identification information corresponding to the path image are deleted from the drawing table  23 C. The process proceeds to Step S 71 . 
     If the browser  20   a  determines not to perform the drawing processing at Step S 60  (No at Step S 60 ), the process proceeds to Step S 75 . The browser  20   a  performs negative determination at Step S 60  when determining that the processing contents indicated by the instruction information included in the operation information [p] acquired at Step S 51  (refer to  FIG. 24 ) include a menu processing instruction. 
     The browser  20   a  performs processing instructed by menu processing included in the operation information [p] (Step S 75 ). The menu processing instruction includes instructions such as a change of display contents, a change of a display color, a change of the path attribute information (display color, line type, thickness, and the like), enlargement, reduction, and capture. 
     The browser  20   a  reflects the setting change by the menu processing performed at Step S 75  (Step S 76 ). The browser  20   a  then stores the setting after being changed by the menu processing at Step S 75  in the storage unit  23  (Step S 77 ). The process proceeds to Step S 71 . By the processing from Step S 75  to S 77 , when a change instruction for the display color of the path image is received as the menu processing, for example, the browser  20   a  changes the path attribute information  23 B stored in the storage unit  23  to the contents depending on the change instruction. 
     It is assumed that the path attribute information included in the operation information [p] acquired by the browser  20   a  is “the same as previous”. In this case, the browser  20   a  generates the path image from the path attribute information  23 B stored in the storage unit  23  and the set of position coordinates indicating the path included in the operation information [p] at the processing at Step S 63 . 
     Returning back to  FIG. 24 , the browser  20   a  renders the content data [A], the content data [E], and the operation image p combined at Step S 71  (refer to  FIG. 25 ) and outputs video (sound) data ([A], [E], [p]) to the transmission FIFO  24   a  (Step S 54 ). 
     The converter  10  encodes the video (sound) data ([A], [E], [p]) stored in the transmission FIFO  24   a , thereby converting it into video (sound) data ([A], [E], [p]) to be distributed to the communication terminal  5   f   1  (Step S 55 ). The encoder bridge unit  30  transmits the video (sound) data ([A], [E], [p]) to the reproduction controller  53  of the communication terminal  5   f   1  through the transmitter/receiver  31  and the transmitter/receiver  51  (Step S 56 ). After that, the video (sound) data ([A], [E], [p]) is decoded by the decoding unit  50  of the communication terminal  5   f   1  to be output as sound to the speaker  61 , or is rendered by the rendering unit  55  to be output as video to the display unit  58  (Step S 57 ). 
     Once the processing from Step S 46  to Step S 57  described with reference to  FIG. 24  and  FIG. 25  is performed, the communication terminal  5   f   1  reproduces the video (sound) data ([A], [E], [p]) in which the path image p of the operation path is combined with video (sound) data depending on the content data [A], [E]. The identification information corresponding to the path information indicating the operation path drawn by the communication terminal  5   f   1  is successively stored in the drawing table  23 C of the distribution management apparatus  2 . This identification information is, as described above, information that identifies the content data corresponding to the video (sound) data being reproduced by the communication terminal  5   f   3  at the drawing timing of the operation path. 
     Thus, the distribution management apparatus  2  according to the present embodiment can dynamically associate the operation path drawn by one communication terminal with the information on the video being reproduced by another communication terminal. 
     Described next is a processing procedure when the communication terminal  5  acquires the identification information. 
     The communication terminal  5   f   1  transmits an acquisition request for the identification information to the distribution management apparatus  2 . Upon receiving the acquisition request from the communication terminal  5   f   1 , the distribution management apparatus  2  causes the browser  20   a  to read the path information corresponding to the terminal ID of the communication terminal  5   f   1  included in the acquisition request and the identification information from the drawing table  23 C. The browser  20   a  adds the path image [p] included in the read path information to the drawing layer in the same manner as Step S 65  (refer to  FIG. 25 ). The browser  20   a  then combines and renders the content data (the content data [B], for example) identified by the identification information and the path image, thereby generating video (sound) data ([B], [p]), and outputs it to the transmission FIFO  24   a  in the same manner as Step S 71 . 
     The browser  20   a  encodes the video (sound) data ([B], [p]), thereby converting it into video (sound) data ([B], [p]) to be distributed to the communication terminal  5   f   1 . The encoder bridge unit  30  transmits the video (sound) data ([B], [p]) to the reproduction controller  53  of the communication terminal  5   f   1  through the transmitter/receiver  31  and the transmitter/receiver  51 . After that, the video (sound) data ([B], [p]) is decoded by the decoding unit  50  of the communication terminal  5   f   1  to be output as sound to the speaker  61 , or is rendered by the rendering unit  55  to be output as video to the display unit  58 . 
     The communication terminal  5   f   1  on which the operation path is drawn is provided with the path image of the drawn operation path and the video (sound) data being reproduced by the other communication terminal at the drawing timing in which the operation path is drawn in response to the request of the user who operates the communication terminal  5   f   1 . This enables the user who operates the communication terminal  5   f   1  to easily check the details of the operation path and the video (sound) displayed on the other communication terminal  5  when the operation path is drawn. 
     Main Effect of the Embodiment 
     As described above, the distribution management apparatus  2  according to the present embodiment performs the processing from Step S 46  to Step S 57  described with reference to  FIG. 24  and  FIG. 25 , thereby performing the following processing: associating the path information indicating the operation path drawn by the communication terminal  5   f   1  with the identification information that identifies the content data corresponding to the video (sound) data being reproduced by the communication terminal  5   f   3  at the drawing timing of the operation path; and storing them in the drawing table  23 C, sequentially. 
     The present embodiment can thereby dynamically associate the operation path drawn by one communication terminal with the information on the video being reproduced by another communication terminal. 
     When the acquisition request for the identification information is received from the communication terminal  5   f   1 , the video (sound) data in which the path image and the video (sound) data being reproduced by the communication terminal  5   f   3  at the drawing timing of the path image are combined is distributed to the communication terminal  5   f   1 . 
     A case is assumed in which an electronic blackboard is used as the communication terminal  5   f   1  and a projector is used as the communication terminal  5   f   3 , for example. In this case, the user draws an operation path with the electronic pen P while watching the video (sound) data reproduced by the communication terminal  5   f   3 , thereby causing operation information to be input to the communication terminal  5   f   1 . In this case, the path information indicating the operation path input by the communication terminal  5   f   1  that is the electronic blackboard and the identification information of the content data corresponding to the video (sound) data being reproduced by the communication terminal  5   f   3  that is the projector at the drawing timing of the operation path are dynamically associated with each other. In response to the acquisition request for the identification information by the operation instruction by the user, the path image of the operation path and the video (sound) data being reproduced by the other communication terminal  5  at the drawing timing of the operation path are distributed from the distribution management apparatus  2  to the communication terminal  5 . 
     This enables the present embodiment, in addition to the above effect, to easily provide the video (sound) data being reproduced by the other communication terminal  5  at the drawing timing of the operation path to the user in a reusable manner and easily. 
     In the distribution system  1  according to the present embodiment, the distribution management apparatus  2  includes the browser  20  and the encoder bridge unit  30  that performs encoding and other operations on the cloud. With this configuration, the browser  20  generates video data or sound data from the content data expressed with a certain description language, and the encoder bridge unit  30  converts the format of the generated data so as to be distributed through the communication network  9  and distributes the converted data to the communication terminal  5 . This reduces a load to receive the content expressed with the certain description language and a load to convert the received content into video data or sound data in the communication terminal  5 . This can in particular resolve the problem in that the load of the communication terminal  5  when utilizing enriched content is high. 
     In particular, the browser  20  enables real-time communication, and the convertor  10  performs real-time encoding on the video (sound) data generated by the browser  20 . Consequently, unlike a case in which a DVD player selects and distributes non real-time (that is, pre-encoded) video (sound) data as seen in, for example, on-demand distribution of video (sound) data, the distribution management apparatus  2  renders content acquired immediately before being distributed, thereby generating pieces of video (sound) data and then encoding it, thus allowing distribution of real-time video (sound) data. 
     Supplementary Description 
     Although the distribution management apparatus  2  according to the present embodiment assumes two communication terminals  5  including the communication terminal  5   f   1  as the electronic blackboard that inputs the operation path and the other communication terminal  5   f   3  as the projector or the like, the other communication terminal  5   f   3  may be a plurality of communication terminals. 
     In this case, the distribution management apparatus  2  may associate pieces of identification information for identifying respective pieces of content data corresponding to respective pieces of video (sound) data that were reproduced by the respective communication terminals  5   f   3  at the drawing timing in the communication terminal  5   f   1  and path information each other and store them in the drawing table  23 C. When a browsing request for the identification information is received from the communication terminal  5   f   1 , the browser  20   a  reads the path information corresponding to the terminal ID of the communication terminal  5   f   1  included in the browsing request and the pieces of identification information from the drawing table  23 C. The browser  20   a  adds the path image [p] included in the read path information to the drawing layer in the same manner as Step S 65  (refer to  FIG. 25 ). The browser  20   a  may then combine a plurality of pieces of content data identified by the pieces of identification information and the path image and output it to the transmission FIFO  24   a  in the same manner as Step S 71 . 
     The browser  20   a  encodes the combined image of the pieces of video (sound) data corresponding to the pieces of content data and the path image stored in the transmission FIFO  24   a , thereby converting it into video (sound) data to be distributed to the communication terminal  5   f   1 . The encoder bridge unit  30  transmits the video (sound) data to the reproduction controller  53  of the communication terminal  5   f   1  through the transmitter/receiver  31  and the transmitter/receiver  51 . After that, the video (sound) data is decoded by the decoding unit  50  of the communication terminal  5   f   1  to be output as sound to the speaker  61 , or is rendered by the rendering unit  55  to be output as video to the display unit  58 . 
     The distribution system  1  according to the present embodiment includes the terminal management apparatus  7  and the distribution management apparatus  2  as separate systems. For example, the terminal management apparatus  7  and the distribution management apparatus  2  may be constructed as an integral system by, for example, causing the distribution management apparatus  2  to have the functions of the terminal management apparatus  7 . 
     The distribution management apparatus  2  and the terminal management apparatus  7  according to the above embodiment may be constructed by a single computer or may be constructed by a plurality of computers in which respective parts (functions, means, or storage units) are divided and assigned arbitrarily. 
     A storage medium such as a CD-ROM storing the programs of the above embodiment and an HDD storing these programs can be provided domestically or abroad. 
     The present invention can exert the effect of dynamically associating an operation path drawn by one communication terminal and information on video being reproduced by another communication terminal. 
     Although the invention has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.