Video Processing in a Multi-Participant Video Conference

• US 20100321469A1
• Filed: 08/27/2010
• Published: 12/23/2010
• Est. Priority Date: 04/28/2005
• Status: Active Grant

• Current Assignee: Hyeonkuk Jeong, Jim Normile, Joe Abuan
• Original Assignee: Hyeonkuk Jeong, Jim Normile, Joe Abuan
• Inventors: Normile, Jim, Jeong, Hyeonkuk, Abuan, Joe
• Granted Patent: US 8,638,353 B2
• Time in Patent Office: Days
• US Class Current: 348/14.09
• CPC Class Codes: H04N 7/147 Communication arrangements, e.g. identifying the communication as a video-communication, intermediate storage of the signals selecting H04Q
• CPC Class Codes: H04N 7/152 Multipoint control units therefor

Abstract

Some embodiments provide an architecture for establishing multi-participant video conferences. This architecture has a central distributor that receives video images from two or more participants. From the received images, the central distributor generates composite images that the central distributor transmits back to the participants. Each composite image includes a set of sub images, where each sub image belongs to one participant. In some embodiments, the central distributor saves network bandwidth by removing each particular participant'"'"'s image from the composite image that the central distributor sends to the particular participant. In some embodiments, images received from each participant are arranged in the composite in a non-interleaved manner. For instance, in some embodiments, the composite image includes at most one sub-image for each participant, and no two sub-images are interleaved.

Claims

1-18. -18. (canceled)

19. A method of providing a participant module for a video conference having a plurality of participants, wherein one participant is a central distributor of video content, said method comprising:

providing a local capture component for receiving a plurality of local video images;

providing a difference comparator module for comparing a first local video image and a subsequent second local video image, wherein the first video image has been transmitted to the central distributor; and

providing an encoder module for transmitting the second video image to the central distributor when the difference comparator module determines that the first and second video images are different.

20. The method of claim 19, wherein the encoder module does not transmit the second video image when the difference comparator module determines that the first and second video images are similar to a certain threshold.

21. The method of claim 19, wherein the difference comparator module compares the first and second video images by computing at least one metric that expresses the difference between the first and second video images.

22. The method of claim 21, wherein the difference comparator module determines that the first and second video images are similar when the metric meets a threshold, and determines that the first and second images are different when the metric does not meet the threshold.

23. The method of claim 19, wherein the second video image is not transmitted to the central distributor when the difference comparator module determines that the first and second video images are similar or identical.

24. The method of claim 19, wherein the difference comparator module is further for maintaining a copy of the second video image to perform a comparison with a subsequent third local video image when the second video image is transmitted to the central distributor.

25. The method of claim 19, wherein the first video image is a last local video image in a series of local video images transmitted to the central distributor during the video conference.

26. The method of claim 19 further comprising providing a decoding module for receiving video images from the central distributor and decoding the video images for display.

27. The method of claim 19 further comprising providing a perspective adjuster for receiving the decoded video images and adjusting the perspective of the decoded video images.

28. A method of eliminating duplicate transmissions in a video conference having a plurality of participants, the method comprising:

providing a set of decoders for receiving and decoding a plurality of encoded video images from the plurality of participants;

providing a frame rate controller module for evaluating the received decoded video images in order to determine whether a particular video image of the received decoded video images is newer than a video image that was previously transmitted to a particular participant; and

providing an encoder for encoding and transmitting the particular image to the particular participant when the particular image is newer than the previously transmitted image.

29. The method of claim 28, wherein the particular image and the previously transmitted image are each associated with a timestamp, wherein the timestamp of the particular image is compared to the timestamp of the previously transmitted image in order to determine which image is newer.

30. The method of claim 28, wherein the frame rate controller evaluates the received decoded image by analyzing a timestamp of an intermediate buffer to determine whether the particular video image is newer than the video image that was previously transmitted.

31. The method of claim 30, wherein the analyzing the timestamp comprises comparing the timestamp against a time corresponding to a last instance when the buffer'"'"'s content was retrieved.

32. The method of claim 30, wherein the received decoded video images is determined to be newer than the video image that was previously transmitted when the timestamp is later than the time corresponding to the last instance.

33. The method of claim 30, wherein the received decoded video images is determined to be not newer than the video image that was previously transmitted when the timestamp is the same as the time corresponding to the last instance.

34. The method of claim 28 further comprising providing a difference comparator for comparing a first local video image transmitted to the particular participant and a subsequent second local video image.

35. A computer readable medium storing a computer program for execution by at least one processor, the computer program comprising:

a set of instructions for sending a first video image captured locally on a computing device to a participant of a video conference;

a set of instructions for determining whether the first local video image and a subsequent second video image captured locally on the computing device are different; and

a set of instructions for sending the second video image to the participant of the video conference when the determination is made that the first and second video images are different.

36. The computer readable medium of claim 35, wherein the set of instructions for determining whether the first and second video images are different comprises a set of instructions for comparing the first local video image to the second local video image by computing at least one metric that expresses the difference between the first and second video images.

37. The computer readable medium of claim 35 further comprising a set of instructions not sending the video image to the participant of the video conference when the determination is made that the first and second video images are similar or identical.

38. The computer readable medium of claim 35 further comprising a set of instructions for maintaining a copy of the second video image to determines whether a third subsequent video image captured locally on the computing device is different from the second video.