JP2005039515A - Network system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform suitable transmission corresponding to the capacity of each transmitting destination in the case of simultaneously transmitting multimedia data to a plurality of transmitting destinations. <P>SOLUTION: In a server 16, a capacity discrimination part 50 discriminates the capacity of each transmitting destination such as the transmission capacity (maximum transmission rate) of a transmission route up to the transmitting destination and the throughput (processing speed or display resolution in the case of a display) of an apparatus in the transmitting destination in each transmitting destination and a resolution setting part 54 sets resolution in accordance with the discriminated capacity of each transmitting destination, converts multimedia data (hereafter referred to MM data) of a transmitting target into the set resolution and transmits the converted data to each transmitting destination. Since the MM data adjusted to suitable information volume in accordance with the capacity of each transmitting destination can be transmitted, suitable transmission corresponding to the capacity of respective transmitting destinations can be performed in the case of simultaneously transmitting the MM data to a plurality of transmitting destinations. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a network system, and more particularly to a network system that transmits multimedia data between a plurality of devices.

  2. Description of the Related Art Conventionally, there is a technique for transmitting multimedia data such as video, images, sounds, and electronic documents via a network. As a typical example, video and audio data shot by a video camera can be sent simultaneously to multiple destinations, and this data can be received at the destination and played back (display / audio output). There is a so-called video conference system that allows people in a place to hold a conference (see, for example, Patent Documents 1 and 2). A technique for automatically creating minutes in such a video conference system has also been proposed (see Patent Document 3).

  Here, video and audio data needs to be transmitted to the client side at a constant transfer rate according to the reproduction time. However, the communication speed of the conventional network is not sufficient for transmission of a large amount of data (hereinafter referred to as large-capacity data) such as high-resolution video data, and there is a problem that a phenomenon such as frame dropping or sound skipping occurs. there were. For this reason, it has been necessary to reduce the amount of data in advance, such as from 30 frames / second to 5 frames / second for video data.

In recent years, a network capable of high-speed and large-capacity data communication called Gigabit Optical Ethernet (R) has been developed. By using this Gigabit Optical Ethernet (R), the amount of data can be reduced. It becomes possible to transmit without. For example, Patent Document 4 describes that a server has a high-speed network interface, and video data read from a shared disk array is transmitted from the server to a client via a network at a constant rate.
Japanese Patent Laid-Open No. 9-294166 JP 2000-152204 A Japanese Patent Laid-Open No. 5-298340 Japanese Patent Laid-Open No. 10-134485

  In general, since various types of devices are connected to the network, when the same data is simultaneously transmitted to a plurality of transmission destinations as in a video conference system, the transmission destination includes a device with a low processing speed. Sometimes. However, in the prior art, the transmission speed of data to a plurality of transmission destinations is uniform, and even if large-capacity data can be simultaneously transmitted to a plurality of transmission destinations using gigabit optical Ethernet (R), If the processing speed of the apparatus is low, there is a risk that the playback process will not be completed and frame dropping and sound skipping may occur. In addition, when there is a part where the transmission speed is partially low on the data transmission path, there is a problem that frame dropping or sound skipping occurs.

  Also, in the case of video data transmission, if the display resolution of the destination display is low, high resolution video data will be sent to the transmission destination even though low resolution video data is sufficient at the transmission destination. There was a problem that would become uselessly expensive.

  The present invention has been made to solve the above-mentioned problem, and in the case of simultaneously transmitting multimedia data to a plurality of transmission destinations, a network system capable of performing appropriate transmission according to the capability of each transmission destination. The purpose is to provide.

  In order to achieve the above object, the invention described in claim 1 is a network system for transmitting multimedia data between a plurality of devices, wherein the transmission destination device and the multimedia data are transmitted for each transmission destination. A discriminating unit for discriminating a processing capability of a medium including a transmission line transmitted until reaching a destination device; and an amount of multimedia data to be transmitted for each destination based on a discrimination result by the discriminating unit. And a server provided with an adjusting means for adjusting to the above.

  According to the first aspect of the present invention, when multimedia data is transmitted, the server on the network uses a determination unit to determine the transmission destination device and the transmission destination device for each transmission destination. The processing capability of the medium including the transmission line through which the media data is transmitted is determined, and the information amount of the multimedia data to be transmitted is adjusted by the adjusting means based on the determination result. The information amount of the multimedia data can be adjusted by changing the resolution of the multimedia data such as time resolution and spatial resolution.

  As a result, it is possible to transmit multimedia data by adjusting to an appropriate amount of information according to the processing capacity of the medium for each transmission destination, that is, the capability of each transmission destination, so that multimedia data can be simultaneously transmitted to a plurality of transmission destinations. When transmitting, it is possible to perform appropriate transmission according to the capability of each destination.

  For example, when a device with a low processing speed is included in the transmission destination, multimedia data with a high information amount is transmitted to a device with a high processing speed, and the information amount is transmitted to a device with a low processing speed. Therefore, there is no fear that a phenomenon such as frame dropping or sound skipping may occur without a proper reproduction process on a device with a low processing speed. Even if there is a part where the transmission speed is partially slow on the transmission path, the amount of multimedia data can be reduced according to the transmission speed of the slow part. There is no worry about dropping or skipping. Furthermore, even when the display resolution of the display of the transmission destination device is low, the information amount of multimedia data, specifically, the resolution can be transmitted to the device with a low resolution. It is possible to prevent the height from becoming useless.

  In the above network system, as described in claim 2, at least one of a current transmission rate of the transmission line, a maximum transmission rate of the transmission line, and a processing speed of the destination device is set. The processing capability may be determined. In this case, as described in claim 3, the adjusting means reduces the amount of information when the determining means determines that the processing capability is equal to or less than a predetermined value. It is good to.

  Further, in the above network system, as described in claim 4, when the transmission destination device is a display device that displays an image, the determination unit is configured as the transmission destination processing capability, The display resolution of the display device may be determined.

  Further, in the above network system, as described in claim 5, when the adjusting means transmits multimedia data to two or more transmission destinations, based on a preset priority. The amount of multimedia data to be transmitted to each of two or more destinations may be differentiated.

  Further, in the above network system, as described in claim 6, at least one information terminal device serving as the destination device is connected to one server, and a plurality of servers are connected at high speed. It can also be configured to connect via a network capable of high-capacity communication.

  Further, in the above network system, as described in claim 7, an optical fiber can be used for the transmission line.

  Further, in the above network system, as described in claim 8, a graded index optical fiber can be used for a part of the transmission line.

  As described above, according to the present invention, multimedia data can be transmitted by adjusting to an appropriate amount of information according to the processing capacity of each transmission destination, so that multimedia data can be simultaneously transmitted to a plurality of transmission destinations. In this case, there is an effect that appropriate transmission according to the capability of each transmission destination can be performed.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a network system to which the present invention is applied.

  In the network system 10 shown in FIG. 1, a closed network (so-called intranet) in each place is made into a group 12, and the groups 12 are mutually connected via a multimedia network (hereinafter referred to as MM network) 14 capable of high-speed and large-capacity data communication. It is configured by connecting to. More specifically, each group 12 is configured to be connected to the MM network 14 via connection means (not shown) by a network device such as a hub, a switching hub, or a router having a high-speed communication function with an external network. .

  The group 12 is configured by using an optical transmission line such as a refractive index distribution type optical fiber as a transmission line for transmitting data, thereby enabling a high speed of G (giga) bps (bit per second) order. Large-capacity data communication can be realized. The MM network 14 can also use an optical transmission line such as a gradient index optical fiber as a transmission line for transmitting data.

  Any fiber can be used as the fiber having a refractive index distribution, but it is resistant to vibration and bending, is easy to lay, and has a refractive index distribution from the viewpoints of end face processing suitability and safety of indoor wiring. (GI-POF) is more preferable. Furthermore, when used for a near-infrared light source of 770 nm or more, absorption loss due to low harmonic absorption of the constituent C—H stretching vibration occurs, so that the (light) hydrogen atom of the C—H bond is replaced with a deuterium atom or Polymers substituted with halogen atoms (for example, fluorine atoms) (for example, deuterated polymethyl methacrylate as described in WO93 / 08488, JP-A-58-149003, JP-A-10-293215, etc.) (PMMA-d8 · d5 · d3), poly (tert-butyl methacrylate) d14, polytrifluoroethyl methacrylate (P3FMA), polyhexafluoroisopropyl 2-fluoroacrylate (HFIP 2-FA), etc.) The wavelength region that causes this transmission loss can be lengthened and the loss of transmission signal light can be reduced.

  The above polymer is preferably a deuterated polymer of acrylic acid ester or methacrylic acid ester monomer from the viewpoint of manufacturing equipment investment and cost. Examples of the polymerizable monomer that can be preferably used include (meth) acrylic acid esters (fluorine-free (meth) acrylic acid ester, fluorine-containing (meth) acrylic acid ester), styrene compounds, vinyl esters, and the like. The core part can be formed from these homopolymers, or a copolymer comprising two or more of these monomers, and a mixture of homopolymers and / or copolymers. Among these, a composition containing (meth) acrylic acid esters as a polymerizable monomer can be preferably used.

  The core composition is preferably formed by polymerization from a polymerizable composition containing at least a polymerizable monomer, a polymerization initiator, and a compound having a refractive index different from that of the polymerizable monomer.

  Next, a gradient index plastic fiber having a core part and a clad part that can be used in the present embodiment as a preferred mode will be described. Some types of gradient index plastic fibers are manufactured by the following manufacturing method. In the following, two types of manufacturing methods will be specifically described, but the present invention is not limited to this.

  First, the first production method includes a first step of polymerizing a polymerizable composition for a cladding part to produce a cylindrical tube that becomes a cladding part, and a polymerizable composition for forming a core part in a hollow part of the cylindrical tube. A second step of forming a region to be a core part by interfacial gel polymerization of the core, and producing a preform having regions corresponding to the core part and the cladding part, respectively, and processing the obtained preform into a desired form A third step of manufacturing the plastic optical member.

  Next, a second production method is a method of polymerizing the outer core polymerizable composition by a rotational polymerization method in a hollow portion of a cylindrical tube made of a fluorine-containing resin such as polyvinylidene fluoride resin, which corresponds to the cladding portion. Then, an outer core layer is formed on the inner wall surface of the cylindrical tube to produce a cylindrical tube having two layers, and the polymerizable composition for forming the inner core portion is interfaced with a further hollow portion of the cylindrical tube. Gel polymerization is performed to form a region to be an inner core portion, and a second step of manufacturing a preform having regions corresponding to the cladding portion, the outer core portion, and the inner core portion, and the obtained preform. And a third step of processing into a desired form.

  In the latter production method, when producing a concentric cylindrical pipe composed of two layers, it is not stepwise as described above, but one step of a method of melt coextrusion of a polymer of a fluororesin and a polymer composition for an outer core. There is also a method of manufacturing by.

  The polymerizable composition for forming the clad part or outer core part includes a polymerizable monomer (for example, polymethyl methacrylate, deuterated polymethyl methacrylate), and a polymerization initiator for initiating polymerization of the polymerizable monomer. A chain transfer agent may be contained. Next, the polymerizable composition for forming the core part or the inner core part includes a polymerizable monomer, a polymerization initiator for initiating polymerization of the polymerizable monomer, a chain transfer agent, and a refractive index different from the refractive index of the monomer as required. A compound having a refractive index (refractive index adjusting component: dopant).

  In the second manufacturing method, by forming the outer core portion between the clad portion and the core portion, it is possible to reduce a decrease in adhesiveness and a decrease in productivity due to a difference in material between the clad portion and the core portion. Yes. The clad part is preferably made of a fluorine-containing resin having high hydrophobicity and capable of increasing the refractive index difference from the core part. Specifically, polyvinylidene fluoride resin or the like is preferred. The cylindrical tube corresponding to the clad portion can be produced by, for example, molding a commercially available fluororesin into a pipe having a desired diameter and thickness by melt extrusion. Furthermore, the above-mentioned polymerizable composition can be rotationally polymerized in the hollow portion of the obtained pipe to form an outer core layer on the inner wall thereof. In addition, a similar structure can be produced by co-extrusion of a polymer comprising the fluororesin and the polymerizable composition.

  Further, when an optical member is produced using a polymerizable composition, a refractive index distribution type optical member can also be produced by using a refractive index adjusting component and giving a gradient to the concentration thereof. Examples of the method of giving a gradient to the concentration of the refractive index adjusting component are described in International Publication WO 93/08488, International Publication WO 03/019252, Pamphlet 2003-75656, JP-A 2003-149463, and the like. There is a method using interfacial gel polymerization.

  The polymerizable composition for forming the clad part, outer core part, and core part is disclosed in International Publication WO 93/08488, International Publication WO 03/019252, Pamphlet 2003-75656, JP-A 2003-149463, and the like. The polymerization initiator, the chain transfer agent, and the polymerizable composition for forming a core part described in 1) are further configured to contain a refractive index adjusting component.

  Next, as for the production method of each step, the methods described in International Publication WO 93/08488 pamphlet, International Publication WO 03/019252 pamphlet, Japanese Patent Laid-Open No. 2003-75656, Japanese Patent Laid-Open No. 2003-149463, etc. In addition, other known techniques and techniques described in Japanese Patent Application Nos. 2002-346250 and 2002-188181 can be used.

  As shown in FIG. 1, each group 12 includes an information processing apparatus 20D to which information input / output devices such as a digital video camera 20A, a digital still camera 20B, and a display 20C are connected, a printer function, a copy function, a facsimile function, and the like. A multifunction device 20F as an information input / output device, an information terminal device 20E for creating / editing various digital data, and a user inputting various instructions, and the like are connected to the server 16 via a connection means (not shown). Connected and configured. The information processing apparatus 20D may be omitted, and information input / output devices such as the digital video camera 20A, the digital still camera 20B, and the display 20C may be connected to the server 14. A scanner device or a printer device can also be used as the information input / output device.

  Within each group 12, various digital video cameras 20A, digital still cameras 20B, displays 20C, multifunction devices 20F, information terminal devices 20E, and various types of multi-media such as video, images, audio, and electronic documents are exchanged between the server 16. Media data (hereinafter referred to as MM data) can be exchanged.

  Each server 16 transmits information on each device acquired from the device in the group 12 to which the server 16 belongs to the other group 12 via the MM network 14 or from the other group 12 via the MM network 14. The received information of each device in the other group 12 is received and held. When MM data is transmitted through the network in the group 12 or the MM network 14, the MM data is processed and transmitted based on the information of each device held in each server 16. .

  In the network system 10 of FIG. 1, each group 12 is also connected to a conventional network 30 (hereinafter referred to as a low-speed network) 30 such as a LAN via a router (not shown). For example, it is possible to communicate with a device not belonging to the MM network 14 or the Internet via the low-speed network 30.

  The server 16 can be a general server having a CPU, RAM, ROM, HDD, communication interface, etc., and a description of the hardware configuration is omitted. The server 16 is preinstalled with a program for transmitting and receiving MM data, and the function shown in FIG. 2 is constructed by executing this program.

  In other words, the server 16 acquires the communication unit 40 that communicates with the outside, the transmission destination recognition unit 42 that recognizes the transmission destination of the MM data in the MM network 14, and information about each group 12 (hereinafter, group information). A group information acquisition unit 44, a memory 46 for storing the acquired group information, a search unit 48 for searching for group information corresponding to the transmission destination from the memory 46, and a capability determination unit 50 for determining the processing capability of the transmission destination A priority determination unit 52 that determines the priority for each transmission destination, a resolution setting unit 54 that sets the resolution of MM data to be transmitted according to the processing capability and priority of the transmission destination, and the group to which the server 16 belongs 12, a change information creation unit 56 that creates change information indicating the content of the change in the content, a change notification unit 58 that notifies the change, and a main control that controls the operation of each unit. 60 and is constructed.

  The group information is acquired for each group 12, and the type of each device included in the group 12, its processing capability (processing speed, display resolution in the case of display, etc.), MM network, etc. Information such as the maximum transmission rate of the transmission path to the group 12 and the maximum transmission rate of the transmission path from the server 16 in the group 12 to each device.

  Further, the resolution indicates time resolution or spatial resolution, and in the case of video data, it means the number of frames per unit time or the number of pixels per unit length. Of course, the higher the resolution, the greater the amount of information in the MM data.

  The communication unit 40 can communicate at high speed with the network to which the server 16 is connected. That is, the server 16 transmits / receives various instruction / designation information and MM data to / from devices in the group 12 to which the server 16 belongs via the communication unit 40 and other groups 12 via the MM network 14. .

  An instruction to transmit MM data and MM data to be transmitted are input to the main control unit 60 from, for example, the information terminal device 20E, which is a device in the group 12 to which the server 16 belongs, via the communication unit 40. This transmission instruction includes information specifying a transmission destination. When transmitting to a plurality of transmission destinations, information specifying a priority for each transmission destination may be included. The transmission destination may be a device in the group 12 to which the server 16 belongs, or a device in another group 12. Of these, information specifying the transmission destination is input to the transmission destination recognition unit 42, information specifying the priority is input to the priority determination unit 52, and MM data is input to the resolution setting unit 54.

  The transmission destination recognition unit 42 recognizes the transmission destination device and the group 12 to which the transmission destination device belongs based on the information specifying the input transmission destination, and notifies the search unit 48 of the result.

  The search unit 48 searches the memory 46 for group information of the group 12 to which the notified transmission destination device belongs. If the group information is not found in the memory 46, the search unit 48 instructs the group information acquisition unit 44 to acquire the group information. If there is group information, the group information is passed to the ability determination unit 50.

  The group information acquisition unit 44 transmits the group information of the designated group 12 to the server 16 of the designated group 12 or the server 16 of the designated group 12 on the MM network 14 via the communication unit 40. Various information constituting group information from an exchange (not shown) provided on the route (the type and processing capacity of each device included in the group 12, the maximum transmission route to the group 12 via the MM network) The transmission rate, the maximum transmission rate of the transmission path from the server 16 in the group 12 to each device) is acquired. The group information acquisition unit 44 stores the acquired information in the memory 46 as group information.

  The capability determination unit 50 functions as a determination unit of the present invention, and includes a transmission destination capability analysis unit 50A and a transmission rate monitoring unit 50B. The transmission destination capability analysis unit 50A analyzes the transmission destination group information passed from the search unit 48, and specifically, the transmission capability (transmission band) to the transmission destination device as the medium processing capability in the present invention. And the processing speed of processing the transmitted MM data (reproduction processing, storage processing, etc.), and if the final transmission destination is a display, the processing capability of the transmission destination device such as the display resolution is determined. It is.

  The transmission capability up to the destination device is the maximum transmission rate of the transmission path connecting the server 16 and the device if the destination is a device in the group 12 to which the server 16 belongs. When the transmission destination is a device in another group 12, the maximum transmission rate to the transmission destination device is the transmission destination from the server 16 to the MM network 14 and the server 16 in the other group 12. As shown in FIG. 3, a low-speed communication network is transmitted on the transmission path such that the MM data is transmitted from the server 16A to the equipment in the group 12 to which the server 16B belongs, as shown in FIG. When 70 is included, the maximum transmission rate that can be transmitted by the low-speed communication network 70 is obtained. That is, the transmission capability to the destination device is not necessarily the maximum transmission rate of the MM network, but is determined by the environment of the transmission path to the destination.

  The transmission rate monitoring unit 50B constantly monitors the current transmission rate as the processing capability of the medium in the present invention via the communication unit 40, and determines the actual capability.

  That is, in the capability determination unit 50, the transmission destination capability analysis unit 50A determines the theoretical capability of the transmission destination, and the transmission rate monitoring unit 50B determines the actual capability. The determination result by the capability determination unit 50 is notified to the resolution setting unit 54.

  The resolution setting unit 54 functions as the adjusting means of the present invention. Specifically, the resolution setting unit 54 determines the resolution of the MM data for each transmission destination based on the determination result notified from the capability determination unit 50, converts the resolution of the MM data to the resolution, and then sets the communication unit 40. To each destination.

  The priority determination unit 52 determines the priority of each transmission destination based on the input priority designation information, and notifies the resolution setting unit 54 of the determination result. The resolution setting unit 54 adjusts the set resolution for each transmission destination according to the determination result notified from the priority determination unit 52. Thereby, when transmitting MM data to a plurality of transmission destinations, the information amount of MM data to be transmitted to each of the plurality of transmission destinations can be differentiated based on the priority set in advance by the user. .

  Further, the main control unit 60 is changed to a device in the group 12 to which the server 16 belongs (additional connection of new device, change of connected device, device) via the communication unit 40 (more specifically, the intra-group communication unit 40A). Is detected), the change information creating unit 56 is notified. In response to this notification, the change information creation unit 56 generates change information indicating the notified change contents and passes the change information to the change notification unit 58. The change notification unit 58 notifies all the groups 12 that the devices in the group 12 have been changed by transmitting the change information to the servers 16 of all the groups 12 via the MM network 14.

  This change information is received by the communication unit 40 of each server 16 and passed to the group information acquisition unit 44. The group information acquisition unit 44 analyzes the received change information, changes the contents of the group information of the group 12 that has received the change notification stored in the memory 46, and updates and stores the contents.

  Next, with reference to FIG. 4, the operation of the server 16 will be described as an operation of the present embodiment. FIG. 4 shows a control processing routine performed by the server 16. Note that the server 16 repeatedly executes the control processing routine of FIG. 4 during startup.

  As shown in FIG. 4, in the server 16, an instruction to transmit MM data is input (step 100), or a device connected to the server 16, that is, a device in the group 12 to which the server 16 belongs is changed. It waits until it detects (step 130) or receives change information (step 140).

  When the MM data transmission instruction is input, the server 16 proceeds from step 100 to step 102, and from the information specifying the transmission destination included in the transmission instruction, the MM data transmission destination device and the group 12 to which the device belongs. Recognize Then, the presence / absence of group information of the group 12 to which the transmission destination device belongs is confirmed, and if there is group information of the group 12 in the memory 46, the process proceeds from the next step 104 to step 108, but there is no group information. In step 104, the group information of the group 12 is acquired and stored, and then the process proceeds to step 108.

  In step 108, the group information of the group 12 to which the transmission destination device belongs is analyzed, and the capability of each transmission destination, specifically, the server 16 to the MM network 14, the server to which the group 12 to which the transmission destination device belongs belongs. 16 is used to determine the data transmission capability to the destination device and the processing capability of the destination device. In the next step 110, the resolution of the MM data is set for each transmission destination based on the determined capability of each transmission destination. Specifically, a destination with high transmission capability and processing capability is set to a relatively high resolution, and a destination with low transmission capability and processing capability is set to a low resolution so as to match the low capability. .

  If the information specifying the priority is included in the transmission instruction of the MM data input in the above-described step 100, the process proceeds from the next step 112 to step 114, and according to the specified priority. The resolution set in step 110 is adjusted. Specifically, the set resolution is adjusted so that the resolution of the transmission destination having a high priority is relatively increased with respect to the resolution of the transmission destination having a low priority.

  After adjusting the resolution, the process proceeds to step 116. If the information for specifying the priority is not included in the MM data transmission instruction input in step 100 described above, the process proceeds from step 112 to step 116 as it is.

  In step 116, the MM data is converted into the set resolution or the adjusted resolution to each designated transmission destination, and transmission is started.

  At this time, if there are many MM data transmission destinations, or the MM data is transmitted by other group 12 servers, the transmission capability determined in step 108 may not be obtained. Therefore, along with the start of transmission of MM data, monitoring of the transmission rate is started in the next step 118. Until the transmission of the MM data is completed, the process returns from step 120 to step 118 through step 124, and the transmission rate is continuously monitored. During the transmission of the MM data, the transmission rate is determined in advance. If it is below the predetermined value, the process proceeds from step 120 to step 122, the resolution of the MM data is reduced, and then the process returns from step 124 to step 118.

  When the transmission of the MM data is completed, an affirmative determination is made at step 124, and the control processing routine of FIG. 4 is ended.

  If the server 16 detects a change in the device connected to the server 16, the server 16 proceeds from step 100 to step 132 through step 130 to create change information indicating the change contents and create all groups. 12 to the server 16 (including the server 16), and the control processing routine of FIG.

  Further, when the change information is received, the server 16 proceeds from step 100 to step 142 through step 130 and step 140, and updates the group information stored in the memory 46 based on the received change information. Thus, the control processing routine of FIG.

  As described above, in this embodiment, for each transmission destination, the resolution is set according to the capability of the transmission destination such as transmission capability and processing capability up to the transmission destination, and MM data is transmitted with the set resolution. It has become. As a result, the MM data can be transmitted by adjusting to an appropriate amount of information according to the capability of each transmission destination. Therefore, when transmitting MM data simultaneously to a plurality of transmission destinations, Appropriate transmission can be performed.

  Thereby, for example, when a device with a low processing speed is included in the transmission destination, MM data with high resolution is transmitted to a device with a high processing speed, and MM data is transmitted to a device with a low processing speed. Since the data can be transmitted at a low resolution, there is no worry that a playback process may not be performed on a device with a low processing speed and a phenomenon such as frame dropping or sound skipping will occur. In addition, even if there is a part where the transmission speed is partially slow on the transmission path, it is possible to transmit by reducing the resolution of the MM data in accordance with the transmission speed of the slow part. There is no worry about skipping or other phenomena. Furthermore, even when the display resolution of the display of the destination device is low, the MM data can be transmitted to the device at a low resolution, so that it is possible to prevent the reproduction processing load from becoming unnecessarily high. Can do.

  Also, the transmission rate during the transmission of MM data is monitored, and when the transmission rate becomes lower than a predetermined value, the resolution of the MM data is adjusted (lowered), so that it corresponds to the actual capability during the transmission of MM data. , More appropriate transmission can be performed.

  In addition, since the resolution of the MM data can be adjusted according to the priority set in advance for a plurality of transmission destinations, the MM data can be transmitted according to the user's wishes. For example, when it is desired to hide details of MM data from a plurality of transmission destination users, the priority of the transmission destination is lowered and MM data with a low resolution is transmitted. Can be.

  Hereinafter, as an embodiment of the present invention, an example will be described in which MM data is transmitted to a plurality of transmission destinations, that is, the transmission source and the transmission destination have a relationship of 1: N (N: an integer of 2 or more).

  First, referring to FIG. 5, an embodiment in which the present invention is applied to reproduce and display a video of a lecture held in a lecture room in each of the lecture room and a remote classroom located away from the lecture room. explain.

  In the example shown in FIG. 5, each of the lecture room 12A and the remote classroom 12B corresponds to the group 12, and the servers 16A and 16B are installed in the lecture room 12A and the remote classroom 12B, respectively. The servers 16A and 16B are connected to a Gigabit optical Ethernet (R) as the MM network 14 via optical hubs 200A and 200B, respectively.

  A digital video camera 20A is installed in the lecture room 12A, and the contents of the lecture by the lecturer are photographed. The digital video camera 20A is connected to the server 16A via the information processing apparatus 20D installed in the lecture room 12A and the optical hub 200A, and the video and audio data acquired by photographing with the digital video camera 20A is MM data. To the server 16A. An optical fiber, which is an optical transmission line, is used for connection between the information processing apparatus 20D, the optical hub 200A, and the server 16A in the lecture room 12A.

  Further, in the lecture room 12A, a large screen projector screen 202, a projector 20G for projecting an image on the projector screen 202, a plurality of displays 20C such as a plasma display (PDP), and a speaker (not shown) for outputting sound. Omitted (for example, built in the PDP) is installed. The information processing apparatus 20D installed in the lecture room 12A is connected to devices such as the projector 20G, the display 20C, and the speaker via an optical fiber that is an optical transmission path. The digital video camera 20A is connected to these devices. The acquired video and audio data is transmitted as MM data, and the video captured by the digital video camera can be displayed on the projector screen 202 and the display 20C. Needless to say, voice output is also performed at the same time as the display.

  A display 20C and speakers (not shown, for example, built in the PDP) are also installed in the remote classroom 12B. The display 20C is connected to the information processing apparatus 20D and the optical hub 200B installed in the remote classroom 12B. And connected to the server 16B on the remote classroom 12B side. An optical fiber that is an optical transmission path is used for connection between the information processing apparatus 20D, the optical hub 200B, and the server 16B in the remote classroom 12B.

  The server 16B on the remote classroom 12B side receives the video and audio data acquired by the digital video camera 20A in the lecture room 12A as MM data from the server 16A on the lecture room 12A side via the MM network 14, and receives it. The transmitted MM data is transmitted to the display 20C via the information processing apparatus 20D in the remote classroom 12B, and the video imaged by the digital video camera can be displayed on the display 20C. Needless to say, voice output is also performed at the same time as the display.

  That is, as described above, the servers 16A and 16B are provided in the lecture room 12A and the remote classroom 12B, respectively, and the servers 16A and 16B are connected via the MM network 14 and various devices in the lecture room 12A and the remote classroom 12B. By connecting (digital video camera, projector, PDP) to the corresponding servers 16A and 16B, the projector screen 202 and the display 20C on the lecture room 12A side and the display 20C on the remote classroom 12B side are connected in the lecture room 12A. You can display the video of the lecture by the lecturer. Thereby, the student who cannot go to the lecture room 12A can receive the same lecture as the student in the lecture room 12A at the same time. At this time, since MM data (video and audio data acquired by a digital video camera) is transmitted with a resolution according to the capabilities of each destination, the lecture can be given without any discomfort due to dropped frames in the lecture room 12A or the remote classroom 12B. Can be attended.

  In the above example, the servers 16A and 16B in the lecture room 12A and the remote classroom 12B are also connected to each device via the optical transmission path, and the MM data is optically communicated. MM data can be transmitted at a high speed and a large capacity in the 12A and the remote classroom 12B. Thus, by enabling high-speed and large-capacity transmission of MM data, video data captured by a digital video camera can be transmitted to each device in an uncompressed state, and the playback processing time in each device Can also be shortened.

  In addition, what is necessary is just to connect each said server 16 and each apparatus, such as the digital video camera 20A, the projector 20G, and the display 20C, suitably via a connection means or a relay means (illustration omitted) as needed. In particular, when transmitting MM data to a plurality of devices in the group 12, such as the projector 20G and the display 20C, such as the server 16A in the lecture room 12A, an optical distributor 204 is provided at various places as a relay unit. The optical signal may be taken into a desired device via 204.

  FIG. 6 shows an example of the optical device 204. In the optical distributor 204 shown in FIG. 6, the light beam transmitted through the optical fiber 300 as the optical transmission path is input from the optical signal input port 302. The light beam input from the optical signal input port 302 is received by the light receiving element 304 and converted into an electrical signal. The electrical signal is amplified by an amplifier 306 such as a preamplifier or a postamplifier, and the waveform shaping device 308 performs waveform shaping. Then, the light emitting element 312 is driven by inputting to the light source driving element 310. As a result, an optical signal is output from the light emitting element 312, and the optical signal is branched by the optical branching device 314 and then output to the plurality of optical fibers 318 via the output port 316. FIG. 6 shows a case where the number of output ports is four and an input signal (MM data) is branched into four and output.

  By using such an optical distributor 204, MM data can be distributed to a plurality of devices in the group 12. Note that the configuration of the optical distributor 204 is not limited to this, as long as the input optical signal can be branched into a plurality of outputs.

(Other examples)
In the above, an embodiment in which the present invention is applied to a form in which lecture videos are reproduced and displayed in a lecture room and a remote classroom, assuming that the transmission source and the transmission destination have a relationship of 1: N (N: an integer of 2 or more). Although described, the present invention can be applied to various other forms.

  For example, in the present invention, an operating room of a university hospital is connected to a lecture room or a medical office of a university hospital via a network, and images of operations currently being performed in the operating room are transmitted, so that many young doctors (interns and students) Medical video information can also be applied to distribution, such as showing the status of surgery. In this case, for example, the digital video camera may be remotely operated (digital zoom, volume operation) on the transmission destination side.

  The present invention can also be applied to a remote monitoring system. Specifically, for example, a hospital room and a nurse center or medical office are connected to a network, and monitor images of hospitalized patients are transmitted to the nurse center or medical office. One example is monitoring the patient's condition while staying there. In this case, an apparatus on the network (for example, the server 16) detects a change in the condition of the patient from the monitor video, and based on the detection result, an alarm signal is sent to a predetermined point on the network such as a nurse center or a medical office of the doctor in charge. It can also be made to send to. In addition, a device that measures the patient's pulse, blood pressure, etc. is provided on the network, and a change in state is detected from the patient's pulse and blood pressure information acquired by this device, and an alarm signal is sent to a predetermined point on the network. Can also be made to send. In addition, for example, the security company may monitor the state of the customer's house by connecting the security company and the customer's house via a network and transmitting a monitor image in the residence to the security company. In this case, if a moving object is detected from the monitor video when the resident is absent, a report may be made that a suspicious person has entered the security company.

  The present invention can also be applied to a video conference system that performs a conference between multiple points. In this case, it is possible to send not only the video of the conference but also the video of the PC screen used for taking notes during the conference. If the correction can be made as appropriate, the result of the correction can be notified to the conference attendee. Similarly, an image of a document used in a meeting may be transmitted. Furthermore, the image of the face of the absent person may be combined with the meeting video to create and transmit an image as if the absent person is attending the meeting. Also, if there are people who have different native languages, such as Japanese and English, the texts included in the audio and video data will be automatically changed from Japanese to English, and from English to Japanese. In addition, a device for automatically translating multilingual languages may be provided on the network so that it can be translated into a language suitable for each attendee. In this case, a device having a function for synthesizing the translation result with voice or text into MM data is provided on the network so that the translation result is reproduced as voice or character telop, and the MM data obtained by synthesizing the translation result is transmitted. It is good to.

  Further, the present invention can be applied to the following forms which are application examples of such a video conference system. That is, as an application example of the video conference system, a person in an environment isolated from the outside such as a clean room or an isolation ward in a factory or laboratory may have a conversation with outside people. In some cases, an English conversation school is connected to a student's home via a network, and the user can communicate with a plurality of native speakers and other students while at home. In addition, debates may be held between debaters at remote locations.

  In addition, by using a video conference system, it is possible to connect convenience stores in various places via a network, and at the convenience store, communicate with people at other convenience stores such as conversations. In this case, in order to protect the privacy, for example, a dedicated space where a display and a video camera are installed is prepared in a convenience store, and a conversation with a person in another convenience store is performed in the dedicated space. Good. In addition, as a place where people can go in and out without hesitation, a convenience store has been taken as an example, but other places such as station premises are also conceivable.

  In addition, by applying the video conference system, legal consultations and management consultations with specialists such as lawyers and management consultants can be conducted while in a remote place. At this time, for example, in the case of legal counseling, there may be information that is not desired to be known between hostile parties (consultants). In such a case, the data sent from the consultant only to specialists such as lawyers and management consultants is sent in high resolution, and the low-resolution data is sent to the opposing party as necessary. Data transmission may be canceled. In addition, a device for encrypting data may be provided on the network so that information that is not desired to be disclosed to the outside can be encrypted and transmitted.

  There is also a concierge service as a consultation service with experts. Specifically, a hotel (concierge) and a plurality of stores are connected to a network, and stores that match the customer's wishes are introduced from the plurality of stores.

  Further, the present invention can be applied to so-called digital cinema distribution for distributing movie video data. Since movies have a long time, the amount of information in the video data is very large, and the transmission of such data to multiple users (viewers) increases the network load. In such a case, the present invention is suitable.

It is a network connection block diagram which shows the structure of the network system which concerns on embodiment of this invention. It is a functional block diagram which shows the function constructed | assembled by the server which concerns on embodiment of this invention. It is a network connection figure which shows an example in case a low-speed network is included on a transmission path. It is a flowchart which shows the control processing routine performed with the server which concerns on embodiment of this invention. It is a figure for demonstrating the Example of this invention made to reproduce | regenerate and display the image | video of the lecture currently performed in the lecture room in each of the remote classroom in the place away from the lecture room and the lecture room. It is a figure which shows an example of an optical distributor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Network system 12 Group 14 Multimedia network 16 Server 40 Communication part 50 Capability discrimination | determination part 52 Priority discrimination | determination part 54 Resolution setting part 60 Main control part

Claims (8)

A network system for transmitting multimedia data between a plurality of devices,
Discriminating means for discriminating a processing capability of a medium including a transmission destination device and a transmission line transmitted until the multimedia data reaches the transmission destination device for each transmission destination;
Adjusting means for adjusting the information amount of multimedia data to be transmitted for each transmission destination based on the determination result by the determining means;
Having a server with
A network system characterized by this. The determination means determines at least one of a current transmission rate of the transmission line, a maximum transmission rate of the transmission line, and a processing speed of the destination device as the processing capability;
The network system according to claim 1. The adjusting means reduces the amount of information when the determining means determines that the processing capacity is equal to or less than a predetermined value.
The network system according to claim 2. The destination device is a display device that displays an image,
The determining means determines the display resolution of the display device as the processing capability,
The adjusting means changes the resolution of the multimedia data according to the display resolution;
The network system according to claim 1. When the adjusting means transmits multimedia data to two or more transmission destinations, the information amount of the multimedia data to be transmitted to each of the two or more transmission destinations is determined based on a preset priority. Discriminate,
The network system according to any one of claims 1 to 4, characterized in that: At least one information terminal device serving as the transmission destination device is connected to one server, and a plurality of servers are connected via a network capable of high-speed and large-capacity communication.
The network system according to any one of claims 1 to 5, wherein: The transmission line is composed of an optical fiber;
The network system according to any one of claims 1 to 6, wherein: A part of the transmission line is composed of a graded index optical fiber,
The network system according to any one of claims 1 to 6, wherein:

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