Apparatus and method for improving the quality of video communication over a packet-based network

• US 20020152440A1
• Filed: 10/26/2001
• Published: 10/17/2002
• Est. Priority Date: 10/27/2000
• Status: Abandoned Application

• Current Assignee: Polycom Israel Limited (Plantronics, Inc.)
• Original Assignee: Polycom Israel Limited (Plantronics, Inc.)
• Inventors: Elbaz, Moshe, Yona, Ilan
• Application Number:
  US10/045,125
• Publication Number:
  US 20020152440A1
• Time in Patent Office: Days
• US Class Current: 714/746
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/89 involving methods or arrangements for detection of transmission errors at the decoder
• CPC Class Codes: H04N 19/895 in combination with error concealment
• CPC Class Codes: H04N 21/4346 involving stuffing data, e.g. packets or bytes synchronisation arrangements in time-division multiplex systems with different or fluctuating information rates H04J3/073
• CPC Class Codes: H04N 21/4788 communicating with other users, e.g. chatting arrangements for providing for computer conferences, e.g. chat rooms, to substation in data switching networks H04L12/1813; distributed application using peer-to-peer [P2P] networks H04L67/104
• CPC Class Codes: H04N 21/6437 Real-time Transport Protocol [RTP]
• CPC Class Codes: H04N 21/64776 for requesting retransmission, e.g. of data packets lost or corrupted during transmission from server ARQ protocols H04L1/18; implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP] H04L69/16

Abstract

A network interface unit is provided with a missing packets repair logical unit, which repairs real time video transmissions by replacing the missing packets. The missing packets repair unit detects and replaces missing packets in a received video stream. The missing packets can be detected by finding packets that are out of sequence.

Claims

1. An apparatus for facilitating multimedia communication between a plurality of endpoints over a packet based network, each respective endpoint sending a compressed video output signal and receiving a compressed video input signal, having at least one network interface to a packet-based network, the network interface comprising:

a missing packets repair logical unit, said missing packets repair logical unit handling missing packets and thereby maintaining continuity of a video stream and reducing traffic over said network.

2. The network interface of claim 1, wherein the missing packets repair logical unit further comprises:

a first analyzer that analyzes if a packet is missing;

a second analyzer that analyzes which Group Of Blocks (GOBs) are in the missing packet; and

a repair unit that replaces the missing packets.

3. The apparatus of claim 1 wherein the network is a local area network.

4. The apparatus of claim 1 wherein the network is a wide area network.

5. The apparatus of claim 1 wherein the video stream is repaired during a video stream receiving.

23. The network interface of claim 1, wherein the missing packets repair logical unit further comprises:

a first analyzer that analyzes if a packet is missing;

a second analyzer that analyzes which Slices are in the missing packet; and

a repair unit that replaces the missing packets.

6. A system comprising:

a network interface unit having

a video stream repair unit that receives a video stream from a real time protocol unit, having

a detector unit that detects missing packets,

an analyzer unit that analyzes which video parts are missing,

a replacement unit that receives an indication from the detector unit that packets are missing, and

information from the analyzer unit, the information including which video parts are missing, and in response to receiving the indication and the information replaces a missing packets in a video stream during transmission of the video stream over a network as part of a receive process.

7. A method for repairing missing packets in video communication over a packet-based network, the method comprising:

analyzing if at least one packet is missing;

determining which Group of Blocks (GOBs) are missing;

preparing new packets which will replace the GOBs; and

sending the new packets to a destination.

8. The method of claim 7 wherein the destination is a point remote from where the analyzing occurs.

9. A method comprising:

transmitting a video session over a network; and

replacing a missing part from the video session while the video session is being transmitted.

10. The method of claim 9 wherein the missing part is replaced in an intermediate node during a receiving process that receives the video session.

11. The method of claim 10 further comprising detecting the missing part during the receiving process.

12. The method of claim 11 wherein detecting the missing part includes detecting if a part of the video session received is out of sequence

13. The method of claim 9 wherein replacing the missing part is dependent on the frame type.

14. The method of claim 12 wherein:

each part of a video session has an ID number; and

analyzing which part is missing comprises

finding the ID number of the last received video session part, and

finding the ID number of a first video session part of a stream currently being analyzed.

15. The method of claim 9 wherein the missing part is at least one GOB.

17. The computer usable storage medium of claim 16 wherein the missing part is replaced in an intermediate node during a receiving process that receives the video session.

18. The computer usable storage medium of claim 17, the method further comprising detecting the missing part during the receiving process.

19. The computer usable storage medium of claim 18 wherein detecting the missing part includes detecting if a part of the video session received is out of sequence

20. The computer usable storage medium of claim 16 wherein replacing the missing part is dependant on a frame type.

21. The computer usable storage medium of claim 19 wherein:

each part of a video session has an ID number; and

analyzing which part is missing comprises;

finding the ID number of the last received video session part, and

finding the ID number of a first video session part of a stream currently being analyzed.

22. The computer usable medium of claim 16 wherein the missing part is a packet.

25. The method of claim 9 wherein the missing part is at least one Slice.

16. A computer usable storage medium having stored thereon a method comprising:

transmitting a video session over a network; and

replacing a missing part from the video session while the video session is being transmitted.

24. A method for repairing missing packets in video communication over a packet-based network, the method comprising:

analyzing if at least one packet is missing;

determining which Slices are missing;

preparing new packets which will replace the Slices; and

sending the new packets to a destination.