Abstract:
Conventional video conference porting sytems access the analog video conference output streams, reconverting these streams back into digital data streams for transmission over the Internet. This significantly degrades these streams. Other conventional video conference porting sytems access the digital data streams, but can only output these streams as a multicast. A pseudo-end point can be connected to a multi-point control unit managing a video conference just as the end point of a participant to the video conference is connected. The pseudo-end point device receives the digital data just as the participating end points receive the digital data. The pseudo-end point is connected to a video conference standard module, which is connectable to manyt pseudo-end points, each acting as a pseudo-participant in a different video conference. The video conference standard module transmits the received digital data as a multicast to one or more unicast servers, and zero, one or more multicast clients.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of Invention  
           [0002]    This invention relates to systems and methods that allow data to be transmitted between a video conference system and a distributed network.  
           [0003]    2. Description of Related Art  
           [0004]    Conventional video conferencing equipment is generally divided into a number of categories. These categories include data stream display and capture equipment, such as cameras, microphones, televisions and speakers, end point equipment that connects a particular video conference participant to another end point device or to a multi-point control unit, and the multi-point control unit, which allows three or more end point devices to participate in a single video conference session.  
           [0005]    The end point equipment is used by participants in a video conference to convert the audio and video signals from the camera and microphone into data transmittable to another other end point device or the multi-point control unit. The end point equipment is also used to convert the transmitted audio and video signals, received at one end point from another end point or from the multi-point control unit, into signals usable by audio and video display devices connected to that end point to play the video and audio signals to the participants.  
           [0006]    The multi-point control unit is a conference bridge that connects the various end points of a single video conference session together when more than two end point devices are to be involved in the video conference. In general, two end point devices can be connected directly to each other. In practice, most video conference sessions, even when only two participants are involved, are routed through a multi-point control device. In general, one multi-point control unit can be used for a number of video conference sessions, where each session has two or more participants. In operation, each of the end points contact the multi-point control unit.  
           [0007]    After data sufficient for the multi-point control unit to authenticate the participants&#39; authorization to participate in a video conference is provided to that multi-point control unit, the multi-point control unit connects that end point device to the one or more other end point devices, so that the user of that end point device can participate in that video conference session. The multi-point control unit, or a video conference administrator or coordinator, confirms a video conference participants&#39; authorization to participate in the video conference based on the video conference participant supplying a predefined password, or the like.  
           [0008]    The H.320 standard is the standard for ISDN video conferencing. The H.323 standard extends the H.320 ISDN video conferencing standards to a standard usable for Internet protocol (IP)-based distributed networks. The Session Initiation Protocol (SIP) is a third video conferencing protocol. Video conference equipment, which uses the H.323 standard, uses standard Internet protocol (IP) handshake and messaging protocols and data and packet formats that would be used on a standard Internet protocol (IP)-based distributed network, such as the Internet, many wide area networks and local area networks, intranets, extranets, and other distributed networks.  
           [0009]    Porting the audio and video data streams of a video conference to a distributed network, such as the Internet, for distribution as a multimedia data stream is known. Conventional video conference broadcasters re-encode the audio and video portions of the video conference through one of two techniques. One technique includes capturing the video portion of the video conference separately, by accessing the analog auxiliary audio and video outputs on one of the video conference end point devices that are being used to participate in a particular video conference session. This first technique is illustrated in FIG. 1.  
           [0010]    A second technique uses an entirely different type of video conference equipment, which allows three or more participants to participate in a video conference without needing a multi-point control unit. This system connects the end point equipment of the various participants in a peer-to-peer style network, where each end point receives the video and audio data streams directly from each of the other end points. This is described as multi-tasking the video conference across the network. In this case, an IPTV client, which is a software application available from Cisco Systems, can be connected to the network to view the data packets of a video conference session as the data packets are passed back and forth between the actual end points participating in the video conference. The IPTV client sits in the background and monitors all of the packets that are transmitted between the end points of the video conference session.  
         SUMMARY OF THE INVENTION  
         [0011]    One advantage of this second system over the first technique is that the audio and video data streams stay in digital form. However, the IPTV client merely listens to the multi-task IP addresses. Thus, there is no centralized streaming server that is able to output a unicast multimedia data stream to a client. Rather, the IPTV client creates a multicast. However, multicasts generally cannot be received by most conventional local area or wide area networks that the video conference has not originated on. Thus, this peer-to-peer system can only be used within a multi-cast capable network, such as a single local or wide area network. As a result, the IPTV client can only make the video conference data available to another IPTV client that is also on a multi-cast capable network.  
           [0012]    The system shown in FIG. 1 accesses the digital video and audio streams of the video conference output by a video conference end point device  60  through the analog output streams output by a video conference standard client  70 . These analog output streams are also used to drive the audio and visual display devices used by the actual video conference participants. The system shown in FIG. 1 reconverts the audio streams back into digital data streams. As a result, the system shown in FIG. 1 can significantly degrade or otherwise distort the video and audio data.  
           [0013]    Additionally, the video and audio data, which is originally in digital format, must be converted to analog format and then reconverted to digital format. As a result, there is a significant delay between receiving the digital video and audio streams at the video conference end point device  60  and transmitting the re-encoded digital video and audio streams. This latency can be as long as 40 seconds. Finally, the system shown in FIG. 1 requires a physical connection between the video conference standard client  70  and a video capture encoding device  80  to transmit analog signals  72  and  74 . As a result, each video capture encoding device  80  can be connected to at most one client  70 .  
           [0014]    This invention provides systems and methods that allow video conference data streams to be transmitted between the video conference participants and clients on a distributed network.  
           [0015]    This invention separately provides systems and methods that allow the transmitted data streams to remain in digital form as the data streams are transmitted between the video conference participants and the clients on the distributed network.  
           [0016]    This invention separately provides systems and methods that allow the transmitted data streams to be transmitted as a unicast on the distributed network.  
           [0017]    This invention separately provides systems and methods that use a pseudo-end point to receive audio and video data streams transmitted between the end point devices actually participating in the video conference session.  
           [0018]    This invention further provides systems and methods that transmit the audio and video data streams from the pseudo-end point device to clients on a distributed network.  
           [0019]    This invention further provides systems and methods that transmit the audio and video data streams from the pseudo-end point device to clients on a distributed network entirely as digital data.  
           [0020]    This invention further provides systems and methods that recode the digital audio and video data streams received by the pseudo-end point device, while the audio and video data streams remain in digital format.  
           [0021]    This invention separately provides systems and methods that use a pseudo-end point such that the access to the video conference data is controlled in the same way that access is controlled for an actual video conference participant.  
           [0022]    This invention separately provides systems and methods that use a pseudo-end point device to inject audio and video data streams stored on the distributed network into the video conference session.  
           [0023]    In various exemplary embodiments of the systems and methods according to this invention, a pseudo-end point device can be connected to a multi-point control unit managing a particular video conference session in the same way as the end point device of an actual participant to the video conference session is connected to that multi-point control unit. The pseudo-end point device receives the digital video conference data packets in the same way that the end point devices of the actual participants receive the digital video conference data packets.  
           [0024]    In various exemplary embodiments, that pseudo-end point device is connected to a video conference standard module. The video conference standard module can be connected to a plurality of different pseudo-end point devices, each acting as a pseudo-participant in a different video conference session. In various exemplary embodiments, the video conference standard module transmits the received audio and video data packets as a multicast to one or more unicast servers, and zero, one or more multicast clients.  
           [0025]    In various exemplary embodiments, the unicast servers include servers able to output unicast multimedia data streams using any known or later-developed protocol or software package, such as, for example, the Microsoft® Windows® Media protocol (Windows® MMS), the Apple® QuickTime® protocol, the Real Networks® Real® protocol, the Internet Engineering Task Force (IETF) Real Time Streaming Protocol (RTSP), or the like.  
           [0026]    These and other features and advantages of this invention are described in, or are apparent from, the following detailed description of various exemplary embodiments of the systems and methods according to this invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0027]    Various exemplary embodiments of this invention will be described in detail, with reference to the following figures, wherein:  
         [0028]    [0028]FIG. 1 is a block diagram illustrating one exemplary embodiment of a conventional system for porting video conference audio and video data streams to a distributed network;  
         [0029]    [0029]FIG. 2 is a block diagram of a first exemplary embodiment of a system for connecting a video conference end point to a distributed network;  
         [0030]    [0030]FIG. 3 is a second exemplary embodiment of a system for connecting an end point of a video conference to a distributed network according to this invention;  
         [0031]    [0031]FIG. 4 is a third exemplary embodiment of a system for connecting a video conference end point to a distributed network according to this invention;  
         [0032]    [0032]FIG. 5 is a fourth exemplary embodiment of a system for connecting a video conference end point to a distributed network according to this invention;  
         [0033]    [0033]FIG. 6 is a flowchart outlining a first exemplary embodiment of a method for distributing the video and audio content of a video conference over a distributed network according to this invention; and  
         [0034]    [0034]FIG. 7 is a flowchart outlining a second exemplary embodiment of the method for distributing the video and audio content of a video conference over a distributed network according to this invention.  
     
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS  
       [0035]    The video conferencing systems and methods according to this invention allow video conferencing systems and Internet-based media streaming systems to converge. In various exemplary embodiments, the systems and methods according to this invention allow the audio and video content of a video conference to be distributed as a multimedia data stream over a distributed network, such as the Internet. In general, the various exemplary embodiments of the systems and methods according to this invention allow a network administrator or video conference coordinator to broadcast a live video conference using standard video streaming techniques and protocols for distributing video streams over distributed networks. This makes use of existing distributed network infrastructures while reducing initial purchase costs, maintenance requirements and installation costs.  
         [0036]    As used herein, the term “video conference standard” encompasses the H.323 standard, the SIP standard, the H.320 standard, and any other known or later-developed standard that provides for the concept of a video conference call. Such standards will usually provide for one or more of some form of call routing, some form of call signaling and alerting, some form of negotiation regarding the capabilities of the video conference end points and the parameters to be used during the video conference, and some form of resource releasing of the resources allocated to the video conference.  
         [0037]    As mentioned above, conventional video conference broadcasters reencode the audio and video portions of the video conference through one of two techniques. As shown in FIG. 1, a video conference end point device  60  implementing a video conference standard outputs three data streams  62 - 66  to a video conference standard client  70  of the conventional video conference broadcasting system. The three streams of data  62 - 66  include a video conference standard messaging stream  62 , a digital video stream  64  and a digital audio stream  66 . It should be appreciated that each of the video streams  62 - 66  are bi-directional between the video conference end point device  60  and the client  70 . Each of the digital video conference standard messaging stream  62 , the digital video stream  64  and the digital audio stream  66  are transmitted between the video conference end point device  60  and the client  70  using an Internet protocol (IP) packet transport method. It should also be appreciated that the digital video stream  64  and the digital audio stream  66  are transmitted between the video conference end point device  60  and the client  70  using the Internet Engineering Task Force (IETF) Real Time Protocol (RTP).  
         [0038]    The video conference standard client  70  converts the digital video stream  64  into an analog composite video signal  72 . The video conference standard client  70  also converts the digital audio signal  66  into a analog line-level audio signal  74 , which are output to a video capture and encoding device  80 . It should be appreciated that the analog composite video signal  72  and the analog line-level audio signal  74  are unidirectional signals from the video conference standard client  70  to the video capture and encoding device  80 .  
         [0039]    The video capture and encoding device  80  captures the analog video frames within the analog video signal  72  and digitizes the analog audio signal  74 . The video capture and encoding device  80  then generates, from the captured analog video frames and the digitized audio signal, digital video signals and audio signals and encodes the digital video and audio signals as video and audio streams, or a combined audio/video data stream, for transmission over a distributed network, such as the Internet. In particular, the video capture and encoding device  80 , depending on the particular streaming software to be used, encodes and packetizes the digitized audio ended video data using different formats based on the selected streaming software to be used. For example, Microsoft and Real Networks use proprietary, closed-system encoding and transmission protocols.  
         [0040]    In contrast, Apple has developed the open system named “QuickTime”, while the Internet engineering task force (IETF) has developed the Real Time Streaming Protocol (RTSP). Any of these open-system or closed-system encoding and packetizing methods can be used by the video capture and encoding device  80  to convert the analog data received from the video conference standard client  70  into digital data suitable for transmission over a distributed network. The video capture and encoding device  80  then outputs the digitized and packetized video and audio data streams  82  to a streaming media server  84 .  
         [0041]    The streaming media server  84 , which for example, can output the digitized and packetized audio and video data as a unicast audio/video data stream  86  using the Microsoft® Windows® Media Protocol (Windows® MMS) or the Real Time Streaming Protocol (RTSP). The output video/audio stream  86  can then be received by any number of clients  300  connected to the distributed network over which the audio/video stream  86  is distributed.  
         [0042]    [0042]FIG. 2 is a block diagram illustrating a first exemplary embodiment of a video conference access system  100  usable to connect a video conference session to a distributed network according to this invention. As shown in FIG. 2, the video conference access system  100  includes a video conference standard module  110  connected to a plurality of video-conference-standard video conference end point devices  190  and one or more of an MMS (or other proprietary system) server  120 , an RTSP server  130  and a web server  140 . If provided, the MMS (or other proprietary system) server  120  is connected over a messaging channel  122  and outputs audio/video streams  124  to one or more MMS (or other proprietary system) clients  210 . The RTSP server  130  is connected over an RTSP messaging channel  132 , and outputs video streams  134  and audio streams  136  to one or more RTSP clients  220 .  
         [0043]    A web server  140  is connected over a link  141  to an administrator client  230 , which is also connected over a link  143  to a serial console  142 . In particular, it should be appreciated that the administrator client  230  and the other clients  210  and  220  are not necessarily part of the video conference access system  100 , while the web server  140  and the serial console  142  are generally part of the video conference access system  100 . However, one or both of the web server  140  and the serial console  142  can be omitted from the video conference access system  100 .  
         [0044]    Each of the video-conference-standard video conference end point devices  190  outputs three data streams to the video conference standard module  110 . These data streams include a bi-directional digital video conference standard messaging stream  192 , a unidirectional digital video stream  194  and a unidirectional digital audio stream  196 . In particular, each of the video and audio streams are encoded using the real time protocol (RTP). Each of the streams  192 - 196  are transmitted between the video conference standard video conference end point device  190  and the video conference standard module  110  using an Internet protocol (IP) packet transport technique.  
         [0045]    Each of the provided servers  120  and  130  receive unidirectional digital video streams  112  and unidirectional audio streams  114  from the video conference standard module  110 . Each of these data streams  112  and  114  is transmitted using an internal digital transport technique. The video conference standard module  110  communicates with the web server  140  using a bidirectional digital messaging stream  116 . This digital messaging stream  116  is also transmitted using the internal digital transport method discussed above with respect to the data streams  112  and  114 . In various exemplary embodiments, the bi-directional digital messaging stream  116  uses a proprietary protocol.  
         [0046]    It should be appreciated that, while various ones of the channels and streams are variously described herein as bi-directional or unidirectional, in various exemplary embodiments, each of the channels and streams disclosed herein as unidirectional can be replaced with one or more bi-directional channels or streams. Similarly, each of the channels disclosed herein as bidirectional can be replaced with one or more unidirectional channels or streams. Likewise, each unidirectional channel or stream can be implemented as two or more unidirectional channels or streams, and each bi-direction channel or stream can be implemented as two or more bidirectional channels or streams.  
         [0047]    [0047]FIG. 3 is a block diagram illustrating a second exemplary embodiment of the video conference access system  100  usable to connect a video conference session to a distributed network according to this invention. The second exemplary embodiment shown in FIG. 3 is generally the same as the first exemplary embodiment shown in FIG. 2. However, in the second exemplary embodiment, a transcoder  150  has been inserted between the video conference standard module  110  and the MMS server  120  and the RTSP server  130 . The transcoder  150  converts the audio and video data streams  112  and  114  received from the video conference standard module  110  from the form output by the video conference standard module  110  to one or more different video and audio streams  152  and  154  usable by various ones of the clients  210  and/or  220 .  
         [0048]    In general, there are a number of different encoding techniques that can be used to compress or encode the video and audio streams  112  and  114  for transmission as digital data over a distributed network. For example, there are at least two common video compression or encoding techniques, while there are at least 4 or 5 common audio compression or encoding techniques. For this reason, some clients may be set up to use a different compression or encoding technique than those used to compress or encode one or both of the video and audio streams  112  and  114 .  
         [0049]    In this case, if that client received the compressed or encoded video and audio streams  112  and  114  directly from the video conference standard module  110 , that client would not be able to decompress or decode one or both of the video or audio streams  112  and  114 . Similarly, the bit rate of one or both of the video and audio streams  112  and  114  as output by the video conference standard module  110  may not match the bit rate required or desired by various clients  210  and/or  220 .  
         [0050]    The transcoder  150  decompresses or decodes the video and audio streams  112  and  114  output from the video conference standard module  110  and recompresses or re-encodes the video and audio streams  114  into one or more different forms as the separate video and audio streams  152  and  154 , and  156  and  158 . Each of these different streams  152 - 158  can use a different video or audio compression or encoding technique and/or use a different bit rate. Additionally, one or more of these different streams  152 - 158  can use the same video and audio compression or encoding techniques and bit rate as the corresponding video and/or audio streams  112  and  114 . Each of these different forms of the transcoded video and audio streams  152 - 158  are output to one or both of the MMS server  120  and/or the RTSP server  130 .  
         [0051]    Each of the different forms of the audio and video streams  152 - 158  provided to the MMS server  120  and the RTSP server  130  can be accessed by the clients by transmitting a unique identifier, such as a specific uniform resource locator (URL), to one of the servers  120  or  130 . Thus, for example, to access a particular set of the video and audio streams  152 - 158 , a user would transmit a specific identifier associated with that particular set to one of the MMS server  120  or the RTSP server  130 . In response, the MMS server  120  or the RTSP server would unicast that particular set of video and audio streams  152 - 158  to that user. In various exemplary embodiments, the specific identifier and the particular set of video and audio streams  152 - 58  that identifier is associated with are displayed to the user on a web page that is associated with the particular video conference the user wishes to view. In this case, the user transmits the specific identifier to the MMS server  120  or the RTSP server  130  by selecting and activating an associated hyperlink.  
         [0052]    [0052]FIG. 4 is a block diagram illustrating a third exemplary embodiment of the video conference access system  100  usable to connect a video conference session to a distributed network according to this invention. The third exemplary embodiment shown in FIG. 4 is generally the same as the first exemplary embodiment shown in FIG. 2. However, in the second exemplary embodiment, a record module  160  ar d one or more storage devices  170  have been connected to the video conference standard module  110 . The record module  160  allows the video and audio streams  112  and  114  to be recorded. Thus, the video and audio streams  112  and  114  can be played back to a client after the video conference has begun, and even after the video conference has ended.  
         [0053]    Alternately, a portion of the video and audio streams  112  and  114  stored in one or more of the one or more storage devices  170  can be read and played back by the record module  160  to the video conference standard module  110  and through the video conference standard module  110  to the video-conference-standard video conference devices  190 . In this way, a previous portion of the video conference can be played back to the participants in the video conference. This could be useful if there was a dispute over what had previously occurred during the video conference, or if a participant was absent during a particular portion of the video conference.  
         [0054]    Finally, the record module  160  and the one or more storage devices  170  can received and store other electronic data uploaded by one of the clients  210  or  220  through the MMS server  120  or the RTSP server  130 , respectively, to the video conference standard module  1   10 . Then, like a recorded portion of the video conference, this uploaded electronic data can be transmitted by the record module  160  to the video conference standard module  110  and through the video conference standard module  110  to the video conference standard video conference devices  190 . In this way, the uploaded electronic data can be displayed to the participants in the video conference.  
         [0055]    The one or more storage devices  170  can include one or more locally located physical storage devices, such as a hard disk, RAM, flash memory, a writeable or re-writeable optical disk, or any other known or later-developed locally located storage device, that is locally implemented, for example, as part of the video conference standard module  110  and/or the record module  160 . Similarly, the one or more storage devices  170  can include one or more remotely located storage devices, such as a storage server, or any other known or later-developed remotely located storage device that is accessed by the record module  160  over a distributed network. Furthermore, the one or more storage devices  170  can include both one or more locally-located storage devices, and one or more remotely-located storage devices.  
         [0056]    [0056]FIG. 5 is a block diagram illustrating a fourth exemplary embodiment of the video conference access system  100  usable to connect a video conference session to a distributed network according to this invention. The fourth exemplary embodiment shown in FIG. 5 is generally the same as the first exemplary embodiment show in FIG. 2. However, in the fourth exemplary embodiment, both the transcoder  150 , described above with respect to FIG. 3, has been inserted between the video conference standard module  110  and the MMS server  120  and the RTSP server and the record module  160  and the one or more storage devices  170 , described above with respect to FIG. 4, have been connected to the video conference standard module  110 .  
         [0057]    As outlined above with respect to FIG. 1, the conventional system shown in FIG. 1 piggy backs on the video conference end point device  60  used by one of the video conference participants. That is, the video conference end point device  60  is the end point of one of the video conference participants. The video conference standard client  70  is thus used both by the video conference participants to convert the digital audio and video streams into analog format so that the video conference video and audio streams can be presented to the video conference participants. The video capture and encoding device  80  piggy backs on these analog signals and reconverts them back into digital format.  
         [0058]    In contrast, in the various exemplary embodiments of the systems and methods according to this invention, such as those outlined above with respect to FIGS.  2 - 5 , the video-conference-standard video conference end point device  190  of the video conference access system  100  is not the video conference device used by one of the actual participants to the video conference. Rather, the video-conference-standard video conference end point device  190  of the video conference access system  100  according to this invention separately interacts with the particular multi-point control unit or a particular video conference in the same way that the video conference end point devices  60  of the actual participants interact with the multi-point control unit. Thus, in general, although not necessarily, the video-conference-standard video conference end point device  190  is not an active participant in that particular video conference session, and does not actively transmit video and audio data to the multi-point control unit as is done by the video conference end point devices  60  of the active participants. Thus, the video-conference-standard video conference end point device  190  acts as a “pseudo-participant” within that particular video conference session.  
         [0059]    This provides several distinct advantages over the conventional system illustrated in FIG. 1. Initially, like any video conference participant, the video-conference-standard video conference device  190  can be located anywhere relative to the other video conference participants. Thus, the video conference standard module  110 , unlike the video capture and encoding device  80 , is not limited to being located in the same room, or even the same physical structure, as the video conference equipment of one of the participants to the video conference.  
         [0060]    Additionally, because the video-conference-standard video conference end point device  190  does not have to have any specific relationship to the other video conference participants, multiple video-conference-standard video conference end point devices  190  can be connected to the video conference standard module  110  and act as “pseudo -participants” to a variety of different video conference sessions at the same time. Thus, the video conference access system  100  acts as a video-conference-standard video conferencing network appliance. The video conference access system  100  can work with any Internet protocol (IP)-based video conference standard network, or even, via an ISDN to video conference standard gateway, with H.320 video conferencing systems. The video conference access system  100  connects with other video-conference-standard video conferencing equipment like any other end point device. This allows an end point device  60  to connect to one of the video-conference-standard video conference end point devices  190  directly, or for one of the video-conference-standard video conference end point devices  190  to connect to a multi-point conference through the multi-point control unit  70 .  
         [0061]    The video conference standard module  110  of the video conference access system  100  takes advantage of existing encoded video and audio data that is already being transmitted between the participants of the particular video conference session. The video-conference-standard video conference end point device  190  acts as a “pseudo-participant” to repackage the existing encoded video data for playback by conventional streaming media players, such as  
         [0062]    In various exemplary embodiments, the unicast servers include servers able to output unicast multimedia data streams using the Microsoft®Windows® Media Player®, the Apple® QuickTime® player, the Real Networks® Real® player. or the like. The video conference standard module  110  takes advantage of the high-quality video compression hardware present in the video-conference-standard video conference end point device  190 . In general, due to the video and audio data remaining in digital format from the time the video and audio streams are received by the video-conference-standard conference end point device  190  until the video and audio streams are transmitted to the clients  210  and  220 , there is little to no latency caused by the video conference access system  100 , such as that caused by the software digitizing and encoding used in the conventional system shown in FIG. 1.  
         [0063]    Moreover, because the clients  210  and  220  receive the exact video and audio signals that the participants to the video conference experience, the experience of the users of the clients  210  and  220  is enhanced relative to the experience of the users of the clients  200  that access the system shown in FIG. 1.  
         [0064]    [0064]FIG. 6 is a flowchart outlining a first exemplary embodiment of a method for distributing the audio and video content of a video conference as a multimedia data stream over a distributed network according to this invention. Beginning in step S 100 , operation continues to step S 200 , where a video conference to be distributed as a multimedia data stream over distributed network is established between two or more video conference end point devices, if a peer-to-peer system is used, or between two or more video conference end point devices and a multipoint control unit. Next, in step S 300 , a video conference pseudo-participant end point unit according to this invention is connected to the established video conference. Then, in step S 400 , the digital video and audio streams of the video conference are supplied from the pseudo-participant end point unit to a streaming module. Operation then continues to step S 500 .  
         [0065]    In step S 500 , the digital video and audio streams supplied to the streaming module are resupplied to one or more streaming servers that have one or more different protocols. These servers include, but are not limited to, servers able to output unicast multimedia data streams using the Microsoft® Windows® Media protocol (Windows® MMS), the Apple® QuickTime® protocol, the Real Networks® Real® protocol, the Internet Engineering Task Force (IETF) Real Time Streaming Protocol (RTSP), or any other known or related developed protocol. Then, in step S 600 , each of the streaming servers converts the supplied digital video and audio streams provided to that particular streaming server into the corresponding protocol implemented by that streaming server. Next, in step S 700 , each different streaming server supplies the converted digital audio and video streams, now in the protocol corresponding to that particular streaming server, to one or more corresponding clients. Operation then continues to step S 800 .  
         [0066]    In step S 800 , a determination is made whether the digital video and audio streams should continue to be captured from the video conference and supplied through the pseudo-participant end point and the streaming module to the streaming servers. If so, operation jumps back to step S 400 . Otherwise, operation continues to step S 900 , where the method ends.  
         [0067]    It should be appreciated that, as outlined above with respect to FIGS. 3 and 5, in step S 500 , supplying the digital video and audio streams from the streaming module to the one or more streaming servers can comprise supplying the particular digita video and audio streams to a particular streaming server at different audio and/or compression rates and/or using different audio and/or video compression and/or encoding techniques.  
         [0068]    [0068]FIG. 7 is a flowchart outlining a second exemplary embodiment of a method for distributing the audio and video content of a video conference as a multimedia data stream over a distributed network according to this invention. As shown in FIG. 7, beginning in step S 1000 , operation continue to step S 1100 , where a video conference is established. Then, in step S 1200 , a pseudo-participant end point is connected to the established video conference. Next, in step S 1300 , the digital video and audio streams from the pseudo-participant end point are supplied to the streaming module. Operation then continues to step S 1400 .  
         [0069]    In step S 1400 , the digital video and audio streams from the streaming module are supplied to one or more streaming servers having one or more different protocols, as well as to a storage device that stores the digital video and audio streams. Next, in step SI  500 , the received digital video and audio streams received at each different streaming server are converted to the protocol corresponding to that stream server. Then, in step S 1600 , the converted digital audio and video streams are supplied, from each different streaming server, in the various protocols corresponding to the different streaming servers, to one or more corresponding clients. Operation then continues to step S 1700 .  
         [0070]    In step S 1700 , a determination is made whether the video conference continues to supply the video and audio data streams to the streaming module, and thence to the different streaming servers. If so, operation continues to step S 1800 . Otherwise, operation jumps to step S 2000 .  
         [0071]    In step S 1800 , a determination is made whether or not to play back any of the portions of the video and audio streams of this video conference that have been stored in the storage device in step S 1400 , or to play back any other data that may have been uploaded and/or stored in the storage device. If so, operation continues to step S 1900 . Otherwise operation jumps back to step S 1300 . In step S 190 C, the stored digital video and/or audio streams and/or the supplied video and/or audio data stored in the storage device is played back into the current video conference. Operation then again jumps back to step S 1300 . In contrast, in step S 2000 , the operation of the method ends.  
         [0072]    In various exemplary embodiments of the video conference access system  100  shown in FIGS.  2 - 5 , the various software and hardware elements are supported by a Linux kernel that provides the network resources. The small operating system footprint and versatile network stack provided by the Linux kernel work exceptionally well with the video conference standard stack. Thus, the video conference standard module  110  is able to seamlessly connect the video conference audio and video digital streams to Internet protocol (IP)-based networks.  
         [0073]    Linux has been proven, in a significant number of embedded devices, to be an extremely functional real time operating system, while still providing necessary system resources. The high performance of Linux in a small specialized device provides the ability to ensure that the video conference access system  100  will be able to meet both present and future streaming media requirements in a fully scalable fashion.  
         [0074]    In various exemplary embodiments, the administrator client  230  allows an administrator to grant or deny permission to a user to view a broadcast. This allows the IT manager or a video conference coordinator to maintain full control over the distribution of proprietary and/or confidential information, while still allowing the transition from conventional media distribution to modern Internet-based content delivery technologies.  
         [0075]    The video conference standard module  110 , the transcoder  150 , the record module  160  and/or the clients  142 ,  210  and/or  220  of the various exemplary embodiments of the video conference access system  100  are, in various exemplary embodiments, implemented on one or more programmed general purpose computers. However, the video conference standard module  110 , the transcoder  150 , the record module  160  and/or the clients  142 ,  210  and/or  220  of the various exemplary embodiments of the video conference access system  100  can also be implemented on one or more special purpose computers, one or more programmed microprocessors or microcontrollers and peripheral integrated circuit elements, one or more ASICs or other integrated circuits, one or more digital signal processors, one or more hardwired electronic or logic circuits such as a discrete element circuit, a programmable logic device such as a PLD, PLA, FPGA or PAL, or the like. In general, any device, capable of implementing a finite state machine that is in turn capable of implementing the flowcharts shown in FIGS. 6 and 7, can be used to implement the video conference standard module  110 , the transcoder  150 , the record module  160  and/or the clients  142 ,  210  and/or  220  of the various exemplary embodiments of the video conference access system  100 .  
         [0076]    It should be understood that each of the video conference standard module  110 , the transcoder  150 , the record module  160  and/or the clients  142 ,  210  and/or  220  shown in FIGS.  2 - 5  can be implemented as portions of a suitably programmed general purpose computer. Alternatively, each of the video conference standard module  110 , the transcoder  150 , the record module  160  and/or the clients  142 ,  210  and/or  220  shown in FIGS.  2 - 5  can be implemented as physically distinct hardware circuits within an ASIC, or using a FPGA, a PDL, a PLA or a PAL, or using discrete logic elements or discrete circuit elements. The particular form each of the video conference standard module  110 , the transcoder  150 , the record module  160  and/or the clients  142 ,  210  and/or  220  shown in FIGS.  2 - 5  will take is a design choice and will be obvious and predicable to those skilled in the art.  
         [0077]    Moreover, the video conference standard module  110 , the transcoder  150 , the record module  160  and/or the clients  142 ,  210  and/or  220  can be implemented as software executing on a programmed general purpose computer, a special purpose computer, a microprocessor or the like. In this case, the video conference standard module  110 , the transcoder  150 , the record module  160  and/or the clients  142 ,  210  and/or  220  can be implemented as a resource residing on a server or the like. The video conference standard module  110 , the transcoder  150 , the record module  160  and/or the clients  142 ,  210  and/or  220  can also be implemented by physically incorporating them into a software and/or hardware system.  
         [0078]    The storage devices  170  can be implemented using any appropriate combination of alterable, volatile or non-volatile memory or non-alterable, or fixed, memory. The alterable memory, whether volatile or non-volatile, can be implemented using any one or more of static or dynamic RAM, a floppy disk and disk drive, a writable or re-rewriteable optical disk and disk drive, a hard drive, flash memory or the like. similarly, the non-alterable or fixed memory can be implemented using any one or more of ROM, PROM, EPROM, EEPROM, an optical ROM disk, such as a CD-ROM or DVD-ROM disk, and disk drive or the like.  
         [0079]    While this invention has been described in conjunction with the exemplary embodiments outlined above, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the exemplary embodiments of the invention, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention.