System and method for performing distributed video conferencing

• US 20050078171A1
• Filed: 11/06/2003
• Published: 04/14/2005
• Est. Priority Date: 10/08/2003
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Wu, Duanpei, Lantz, Keith A., Sarkar, Shantanu, Friedrich, Walter R., Firestone, Scott S., Ismail, Nermin M., Surazski, Luke K.
• Granted Patent: US 6,989,856 B2
• Time in Patent Office: Days
• US Class Current: 348/14.80
• CPC Class Codes: H04L 12/1822 Conducting the conference, e.g. admission, detection, selection or grouping of participants, correlating users to one or more conference sessions, prioritising transmission
• CPC Class Codes: H04L 65/4046 with distributed floor control
• CPC Class Codes: H04L 65/765 intermediate
• CPC Class Codes: H04M 2207/20 hybrid systems
• CPC Class Codes: H04M 3/567 Multimedia conference systems
• CPC Class Codes: H04N 7/14 Systems for two-way working H04N7/12, H04N7/173 take precedence
• CPC Class Codes: H04N 7/15 Conference systems

Abstract

A method for executing a video conference is provided that includes receiving one or more audio streams associated with a video conference from one or more end points and determining an active speaker associated with one of the end points. Audio information associated with the active speaker may be received at one or more media switches. One or more video streams may be suppressed except for a selected video stream associated with the active speaker, the selected video stream propagating to one or more of the media switches during the video conference. The selected video stream may be replicated such that it may be communicated to one or more of the end points associated with a selected one of the media switches.

Claims

1. An apparatus for performing distributed video conferencing, comprising:

an audio bridge operable to receive audio data from a first and a second end point; and

a video bridge operable to receive video data from the first and second end points, wherein the first and second end points are operable to connect to a video conference, the audio bridge being operable to identify a size of a first and a second jitter buffer for the first and second end points respectively and to send audio data from the first and second end points to the first and second jitter buffers, the audio bridge being further operable to sum together outputs of the first and second jitter buffers to create a single mixed audio output stream, the audio bridge determining an input-to-output mapping for each input audio output stream to the mixed audio stream, whereby the audio bridge can communicate the mapping to the video bridge, the video bridge being operable to receive one or more video streams and to delay each of the video streams such that the mapping may be reproduced, the video bridge being operable to identify which of the video streams are arriving at a latest time and to delay all of the other video streams such that an input-to-output matching of each individual video stream is matched to the mapping of a corresponding audio stream, a mixed output video stream may be created by mixing the delayed video streams, whereby the mixed outputs from the audio bridge and the video bridge may be communicated back to each of the first and second end points such that the video conference is facilitated.

2. The apparatus of claim 1, wherein the video bridge is operable to delay each of the video streams such that the mapping may be reproduced while minimizing a total delay by setting one of a plurality of delays to zero.

3. The apparatus of claim 1, further comprising:

a media switch that includes the audio bridge and the video bridge and that is operable to control the first and second end points and to connect the first and second end points to the audio bridge and the video bridge.

4. The apparatus of claim 1, wherein the audio bridge is operable to sum together outputs of the first and second jitter buffers to create the single mixed audio output stream with a network time protocol (NTP) time stamp, the audio bridge being further operable to map the NTP time stamp of each input stream to the mixed audio output stream.

5. The apparatus of claim 1, wherein the audio bridge further comprises an audio mixer operable to facilitate operations of the audio bridge by mixing audio data received from the first and second end points.

6. The apparatus of claim 1, wherein the video bridge further comprises a video mixer operable to facilitate operations of the video bridge by mixing video data received from the first and second end points.

7. The apparatus of claim 1, further comprising:

a gateway operable to provide connectivity to one or more media switches, one or more of the media switches being operable to facilitate participation in the video conference by the first and second end points.

8. The apparatus of claim 1, further comprising:

a call manager operable to provide a communicative platform from which the first and second end points can participate in the video conference.

9. A method for performing distributed video conferencing, comprising:

receiving audio data from a first and a second end point;

receiving video data from the first and second end points, wherein the first and second end points are operable to connect to a video conference;

identifying a size of a first and a second jitter buffer for the first and second end points respectively;

communicating audio data from the first and second end points to the first and second jitter buffers;

summing together outputs of the first and second jitter buffers to create a single mixed audio output stream;

determining an input-to-output mapping for each input audio output stream to the mixed audio stream;

receiving one or more video streams;

delaying one or more of the video streams such that the mapping may be reproduced;

identifying which of the video streams are arriving at a latest time and delaying all of the other video streams such that an input-to-output matching of each individual video stream is matched to the mapping of a corresponding audio stream; and

creating a mixed output video stream by mixing the delayed video streams, whereby the mixed outputs may be communicated back to each of the first and second end points such that the video conference is facilitated.

10. The method of claim 9, wherein the delaying of one or more of the video streams is performed while minimizing a total delay and is executed by setting one of a plurality of delays to zero.

11. The method of claim 9, further comprising:

controlling data flows from the first and second end points; and

connecting the first and second end points to the video conference.

12. The method of claim 9, wherein summing together the outputs of the first and second jitter buffers includes summing the outputs to create the single mixed audio output stream with a network time protocol (NTP) time stamp, whereby the NTP time stamp of each input stream may be matched to the mixed audio output stream.

13. The method of claim 9, further comprising:

providing connectivity to one or more media switches, one or more of the media switches being operable to facilitate participating in the video conference by the first and second end points.

14. The method of claim 9, further comprising:

providing a communicative platform from which the first and second end points can participate in the video conference, the communicative platform providing a managerial function in order to facilitate initiation of the video conference.

15. A system for performing distributed video conferencing, comprising:

means for receiving audio data from a first and a second end point;

means for receiving video data from the first and second end points, wherein the first and second end points are operable to connect to a video conference;

means for identifying a size of a first and a second jitter buffer for the first and second end points respectively;

means for communicating audio data from the first and second end points to the first and second jitter buffers;

means for summing together outputs of the first and second jitter buffers to create a single mixed audio output stream;

means for determining an input-to-output mapping for each input audio output stream to the mixed audio stream;

means for receiving one or more video streams;

means for delaying one or more of the video streams such that the mapping may be reproduced;

means for identifying which of the video streams are arriving at a latest time and delaying all of the other video streams such that an input-to-output matching of each individual video stream is matched to the mapping of a corresponding audio stream; and

means for creating a mixed output video stream by mixing the delayed video streams, whereby the mixed outputs may be communicated back to each of the first and second end points such that the video conference is facilitated.

16. The system of claim 15, wherein the delaying of one or more of the video streams is performed while minimizing a total delay and is executed by setting one of a plurality of delays to zero.

17. The system of claim 15, further comprising:

means for controlling data flows from the first and second end points; and

means for connecting the first and second end points to the video conference.

18. The system of claim 15, wherein summing together the outputs of the first and second jitter buffers includes summing the outputs to create the single mixed audio output stream with a network time protocol (NTP) time stamp, whereby the NTP time stamp of each input stream may be matched to the mixed audio output stream.

19. The system of claim 15, further comprising:

means for providing connectivity to one or more media switches, one or more of the media switches being operable to facilitate participating in the video conference by the first and second end points.

20. The system of claim 15, further comprising:

means for providing a communicative platform from which the first and second end points can participate in the video conference, the communicative platform providing a managerial function in order to facilitate initiation of the video conference.

21. Software for performing distributed video conferencing, the software being embodied in a computer readable medium and comprising computer code such that when executed is operable to:

receive audio data from a first and a second end point;

receive video data from the first and second end points, wherein the first and second end points are operable to connect to a video conference;

identify a size of a first and a second jitter buffer for the first and second end points respectively;

communicate audio data from the first and second end points to the first and second jitter buffers;

sum together outputs of the first and second jitter buffers to create a single mixed audio output stream;

determine an input-to-output mapping for each input audio output stream to the mixed audio stream;

receive one or more video streams;

delay one or more of the video streams such that the mapping may be reproduced;

identify which of the video streams are arriving at a latest time and delaying all of the other video streams such that an input-to-output matching of each individual video stream is matched to the mapping of a corresponding audio stream; and

create a mixed output video stream by mixing the delayed video streams, whereby the mixed outputs may be communicated back to each of the first and second end points such that the video conference is facilitated.

22. The medium of claim 21, wherein the delaying of one or more of the video streams is performed while minimizing a total delay and is executed by setting one of a plurality of delays to zero.

23. The medium of claim 21, wherein the code is further operable to:

control data flows from the first and second end points; and

connect the first and second end points to the video conference.

24. The medium of claim 21, wherein summing together the outputs of the first and second jitter buffers includes summing the outputs to create the single mixed audio output stream with a network time protocol (NTP) time stamp, whereby the NTP time stamp of each input stream may be matched to the mixed audio output stream.

25. The medium of claim 21, wherein the code is further operable to:

provide connectivity to one or more media switches, one or more of the media switches being operable to facilitate participating in the video conference by the first and second end points.

26. The medium of claim 21, wherein the code is further operable to:

provide a communicative platform from which the first and second end points can participate in the video conference, the communicative platform providing a managerial function in order to facilitate initiation of the video conference.