System and method for performing distributed multipoint video conferencing

• US 20070064901A1
• Filed: 08/24/2005
• Published: 03/22/2007
• Est. Priority Date: 08/24/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Wu, Duanpei, Baird, Randall, Firestone, Scott, Surazski, Luke
• Granted Patent: US 8,614,732 B2
• Time in Patent Office: Days
• US Class Current: 379/202.10
• CPC Class Codes: H04N 7/15 Conference systems
• CPC Class Codes: H04N 7/152 Multipoint control units therefor

Abstract

According to an embodiment of the present invention, an apparatus for performing video conferencing is provided that includes an I-frame injector element operable to intercept I-frame requests from one or more end points and to attempt to service the I-frame requests such that at least a portion of the requests are prevented from propagating back to an originating sender. In more specific embodiments, when a receiver endpoint sends a fast video update (FVU) request upstream, it is intercepted by the I-frame injector element and rather than passing the FVU request to the sender the I-frame injector element replaces a next P-frame from the sender with an I-frame, whereby the I-frame is constructed so that when decoded, it matches the P-frame that it replaced. In still more detailed embodiments, the I-frame injector element operates in one of three modes that are associated with bandwidth parameters.

Claims

1. An apparatus for performing video conferencing, comprising:

an I-frame injector element operable to intercept I-frame requests from one or more end points and to attempt to service the I-frame requests such that a least a portion of the requests are prevented from propagating back to an originating sender.

2. The apparatus of claim 1, wherein the I-frame injector element normally passes a video stream untouched from input to output, and wherein while passing the video stream, the I-frame injector element internally decodes the video stream and keeps a recently decoded frame in memory.

3. The apparatus of claim 1, wherein when a receiver endpoint sends a fast video update (FVU) request upstream, it is intercepted by the I-frame injector element and rather than passing the FVU request to the sender the I-frame injector element replaces a next P-frame from the sender with an I-frame, whereby the I-frame is constructed so that when decoded, it matches the P-frame that it replaced.

4. The apparatus of claim 1, further comprising:

a media switch that includes the I-frame injector element, an audio bridge, and a video bridge and that is operable to connect end points to the audio bridge and the video bridge.

5. The apparatus of claim 1, wherein the I-frame injector element resides in a network path between a video sender and a video receiver.

6. The apparatus of claim 1, wherein the I-frame injector element is implemented in a satellite broadcast configuration, whereby a one-way network is provided and straddles at least two media switches, whereby at least one of the media switches includes the I-frame injector element.

7. The apparatus of claim 1, wherein the I-frame injector element operates in one of three modes that are associated with bandwidth parameters.

8. The apparatus of claim 7, wherein in a first mode the I-frame injector element is in a smart mode, high bandwidth arrangement, whereby the I-frame injector element intercepts an I-frame request and does not pass it upstream, the I-frame injector element encoding an I-frame that matches a recently decoded video frame from the sender, and wherein the I-frame injector element may then switch over to the sender'"'"'s stream starting with a next frame such that synchronization is achieved.

9. The apparatus of claim 7, wherein in a second mode the I-frame injector element is in a smart mode, low bandwidth arrangement, whereby the I-frame injector element intercepts an I-frame request and does not pass it upstream, the I-frame injector element encoding a new stream and spreading bandwidth over a series of frames, and wherein the I-frame injector element then sends a series of P-frames until the injected stream is synchronized with the sender'"'"'s stream at which time the I-frame injector element switches over to an original stream.

10. The apparatus of claim 7, wherein in a third mode the I-frame injector element is in a dumb mode, the I-frame injector element allowing an I-frame request pass to a sender, whereby until the I-frame arrives, the I-frame injector element re-encodes a sender'"'"'s stream thereby creating an immediate I-frame, and wherein when an I-frame comes from the sender, the I-frame injector element switches over to the sender'"'"'s stream.

11. A method for performing video conferencing, comprising:

intercepting I-frame requests at an I-frame injector element, the requests originating from one or more end points; and

attempting to service the I-frame requests such that a least a portion of the requests are prevented from propagating back to an originating sender.

12. The method of claim 11, wherein while passing a video stream, the I-frame injector element internally decodes the video stream and keeps a recently decoded frame in memory.

13. The method of claim 11, wherein when a receiver endpoint sends a fast video update (FVU) request upstream, it is intercepted by the I-frame injector element and rather than passing the FVU request to the sender the I-frame injector element replaces a next P-frame from the sender with an I-frame, whereby the I-frame is constructed so that when decoded, it matches the P-frame that it replaced.

14. The method of claim 11, wherein the I-frame injector element is implemented in a satellite broadcast configuration, whereby a one-way network is provided and straddles at least two media switches, whereby at least one of the media switches includes the I-frame injector element.

15. The method of claim 11, wherein the I-frame injector element operates in one of three modes that are associated with bandwidth parameters.

16. The method of claim 15, wherein in a first mode the I-frame injector element is in a smart mode, high bandwidth arrangement, whereby the I-frame injector element intercepts an I-frame request and does not pass it upstream, the I-frame injector element encoding an I-frame that matches a recently decoded video frame from the sender, and wherein the I-frame injector element may then switch over to the sender'"'"'s stream starting with a next frame such that synchronization is achieved.

17. The method of claim 15, wherein in a second mode the I-frame injector element is in a smart mode, low bandwidth arrangement, whereby the I-frame injector element intercepts an I-frame request and does not pass it upstream, the I-frame injector element encoding a new stream and spreading bandwidth over a series of frames, and wherein the I-frame injector element then sends a series of P-frames until the injected stream is synchronized with the sender'"'"'s stream at which time the I-frame injector element switches over to an original stream.

18. The method of claim 15, wherein in a third mode the I-frame injector element is in a dumb mode, the I-frame injector element allowing an I-frame request pass to a sender, whereby until the I-frame arrives, the I-frame injector element re-encodes a sender'"'"'s stream thereby creating an immediate I-frame, and wherein when an I-frame comes from the sender, the I-frame injector element switches over to the sender'"'"'s stream.

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

intercept I-frame requests at an I-frame injector element, the requests originating from one or more end points; and

attempt to service the I-frame requests such that a least a portion of the requests are prevented from propagating back to an originating sender.

20. The medium of claim 19, wherein the code is further operable to:

internally decode a video stream and keeps a recently decoded frame in memory.

21. The medium of claim 19, wherein when a receiver endpoint sends a fast video update (FVU) request upstream, it is intercepted and rather than passing the FVU request to the sender, the code replaces a next P-frame from the sender with an I-frame, whereby the I-frame is constructed so that when decoded, it matches the P-frame that it replaced.

22. The medium of claim 19, wherein the I-frame injector element is implemented in a satellite broadcast configuration, whereby a one-way network is provided and straddles at least two media switches, whereby at least one of the media switches includes the I-frame injector element.

23. The medium of claim 19, wherein the I-frame injector element operates in one of three modes that are associated with bandwidth parameters.

24. The medium of claim 23, wherein in a first mode the I-frame injector element is in a smart mode, high bandwidth arrangement, whereby the I-frame injector element intercepts an I-frame request and does not pass it upstream, the I-frame injector element encoding an I-frame that matches a recently decoded video frame from the sender, and wherein the I-frame injector element may then switch over to the sender'"'"'s stream starting with a next frame such that synchronization is achieved.

25. The medium of claim 23, wherein in a second mode the I-frame injector element is in a smart mode, low bandwidth arrangement, whereby the I-frame injector element intercepts an I-frame request and does not pass it upstream, the I-frame injector element encoding a new stream and spreading bandwidth over a series of frames, and wherein the I-frame injector element then sends a series of P-frames until the injected stream is synchronized with the sender'"'"'s stream at which time the I-frame injector element switches over to an original stream.

26. The medium of claim 23, wherein in a third mode the I-frame injector element is in a dumb mode, the I-frame injector element allowing an I-frame request pass to a sender, whereby until the I-frame arrives, the I-frame injector element re-encodes a sender'"'"'s stream thereby creating an immediate I-frame, and wherein when an I-frame comes from the sender, the I-frame injector element switches over to the sender'"'"'s stream.