Adaptive Video Telephone System

• US 20080158333A1
• Filed: 04/27/2005
• Published: 07/03/2008
• Est. Priority Date: 04/30/2004
• Status: Active Grant

• Current Assignee: Hublink, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: WorldGate Service, Inc.
• Inventors: Augenbraun, Joseph E., Krisbergh, Hal M., Kannan, Navneeth, Wachob, David E., Gort, Randall J., Reavy, Maire D., Blackmon, Whitney D., Jesup, Randell E., Westerfer, Richard E.
• Granted Patent: US 8,089,502 B2
• Time in Patent Office: Days
• US Class Current: 348/14.01
• CPC Class Codes: H04N 19/115 Selection of the code volume for a coding unit prior to coding
• CPC Class Codes: H04N 19/137 Motion inside a coding unit, e.g. average field, frame or block difference
• CPC Class Codes: H04N 19/166 concerning the amount of transmission errors, e.g. bit error rate [BER]
• CPC Class Codes: H04N 19/17 the unit being an image region, e.g. an object
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/65 using error resilience
• CPC Class Codes: H04N 19/89 involving methods or arrangements for detection of transmission errors at the decoder

Abstract

A videophone system providing high resolution video transmission between videophones utilizes compressed video signals and audio signals which may be transmitted through any communications network, with the system providing real time adaptive error recovery and synchronization between the audio and video signals to produce high quality video images and sound. The system is highly resilient, adapting in real time to changing conditions in a network or to network errors due to data corruption or loss that can be produced, for example, by noise or line losses, thereby substantially eliminating fitter, signal packet loss or delay, or other errors which produce signal degradation.

Claims

1. A videotelephone system, comprising:

first and second videophones each having a camera connected to an encoder and a transmitter, and having a decoder connected to a display;

a network interconnecting the encoders and decoders of said videophones for video communication; and

wherein said encoders are adaptively responsive to network-caused errors in said communication to provide real-time error recovery.

2. The system of claim 1, wherein said encoders for said transceivers transmit compressed audio and video signals through said communications network.

3. The system of claim 2, wherein said audio and video signals are synchronized.

4. The system of claim 1, wherein each of said encoders is responsive to image video signals from its corresponding camera to produce data representing the image.

5. The system of claim 4, wherein said data representing a current image is dependent on data representing a prior image.

6. The system of claim 5, wherein the decoder of said first transceiver is in communication with encoder of said second transceiver;

and wherein said encoder includes means responsive to changes in conditions in said communications network to adapt said encoder to such changes.

7. The system of claim 6, wherein said means responsive to changes includes means to change the bandwidth requirement for transmitted data.

8. The system of claim 7, wherein said means to change the bandwidth requirement includes at least one of the group of bandwidth-changing mechanisms comprising:

increasing the compression ratio of transmitted video image signals, modifying the frame resolution of transmitted video images, reducing the pocket rate of transmitted encoded video image data, or changing said communication network.

9. The system of claim 4, wherein each of said encoders includes means to produce a first data packet corresponding to video signals representing a first video image frame, and means to produce additional data packets corresponding to video signals representing subsequent video image frames.

10. The system of claim 4, wherein said additional data packets represent only the differences between said first image frame and said subsequent image frames.

11. The system of claim 10, wherein said first data packet is a reference for each subsequent data packet;

and wherein reference data packets are produced at a predetermined frequency.

12. The system of claim 11, wherein the frequency at which reference packets are produced by an encoder is adaptively varied by the encoder in response to said network-caused errors.

13. The system of claim 1, wherein said first and second transceivers are video telephones.

14. The system of claim 1, wherein said communications network produces errors in video communication due to data corruption or loss.

15. The system of claim 14, wherein said adaptively responsive encoders and decoders respond in real time to said data corruption or loss in said communication network to provide said error recovery.

16. The system of claim 15, wherein said error recovery is based on previously-transmitted reference data.

17. The system of claim 1, further including means for storing or displaying received video in each of said transceivers.

18. A method of high resolution video communication, comprising:

transmitting compressed video data signals representing an image through a communications network;

detecting network-caused errors in said video data signals;

adaptively changing said video data signals in real time to provide error recovery; and

storing or displaying said image.

19. The method of claim 18, wherein transmitting compressed video signals includes:

obtaining a series of video image frames;

encoding a first frame to generate a first packet of video data signals;

encoding subsequent frames to generate corresponding subsequent video data packet signals; and

supplying said data packet signals sequentially to said communications network.

20. The method of claim 19, wherein encoding said first packet of video data signals produces a reference frame packet;

and

wherein encoding each subsequent packet of video data signals produces signed packets representing the difference between a subsequent frame and its immediately preceding frame.

21. The method of claim 20, wherein adaptively changing said video data signals in real time includes encoding a subsequent packet of video data signals to produce a signal packet representing the difference between the subsequent frame and said reference frame upon detection of network-caused errors.

22. The method of claim 21, further including producing multiple frame reference packets for a set of subsequent packets.

23. The method of claim 21, further including repetitively and producing a reference data packet followed a set of subsequent frame data packets, wherein providing error recovery includes varying the frequency at which reference frame data packets are produced.