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

• US 7,818,772 B2
• Filed: 07/18/2002
• Issued: 10/19/2010
• Est. Priority Date: 07/18/2001
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Polycom Incorporated (HP Inc.)
• Inventors: Elbaz, Moshe, Yona, Ilan
• Primary Examiner(s): Kelley; Christopher
• Assistant Examiner(s): Andramuno; Franklin S
• Application Number:
  US10/199,872
• Publication Number:
  US 20030037337A1
• Time in Patent Office: 3,015 Days
• Field of Search: 725/90, 725/127
• US Class Current: 725/90
• CPC Class Codes: H04N 21/234327 by decomposing into layers, e.g. base layer and one or more enhancement layers
• CPC Class Codes: H04N 21/23439 for generating different versions
• CPC Class Codes: H04N 21/2625 for delaying content or additional data distribution, e.g. because of an extended sport event
• CPC Class Codes: H04N 21/44004 involving video buffer management, e.g. video decoder buffer or video display buffer
• CPC Class Codes: H04N 21/44209 Monitoring of downstream path of the transmission network originating from a server, e.g. bandwidth variations of a wireless network arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896
• CPC Class Codes: H04N 21/64322 IP
• CPC Class Codes: H04N 21/6437 Real-time Transport Protocol [RTP]
• CPC Class Codes: H04N 7/16 Analogue secrecy systems; Analogue subscription systems

Abstract

A system and method for improving quality of video communication includes a packets generator logical unit (PGU) coupled to a video source for receiving a compressed video stream and generating primary and secondary data chunks for transmittal to one or more destination nodes via a network. Each primary data chunk is associated with a secondary data chunk, and each secondary data chunk includes video data that covers a same portion of a video frame as video data included in each associated primary data chunk. The PGU encapsulates the primary and secondary data chunks in associated primary-secondary packet pairs composed of MB data fields, picture header fields, GOB and slice start header fields, and MB header fields, among others. The destination nodes process the secondary packets received via the network if the primary packets are damaged or lost in transmission.

Claims

1. A system for improving quality of video communication over a packet-based network, comprising:

a packets generator logical unit (PGU) coupled to a video source for receiving a compressed video stream and processing the compressed video stream to generate a stream of primary data chunks and a stream of secondary data chunks, each secondary data chunk associated with a primary data chunk, and to generate packets from the stream of primary data chunks and secondary data chunks; and

a network controller coupled to the PGU and coupled to the packet-based network for sending the packets to one or more destination nodes,

wherein the PGU delays sending each secondary data chunk with respect to its associated primary data chunk,

wherein each secondary data chunk contains data corresponding to at least a portion of a video frame covered by the corresponding primary data chunk, and

wherein the secondary data chunk is delayed such that it arrives at the one or more destination nodes after the associated primary data chunk but before a declaration by the one or more destination nodes that the associated primary data chunk is lost.

2. The system of claim 1, wherein video data included in each secondary data chunk and video data included in each associated primary data chunk cover a same portion of a video frame.

3. The system of claim 1, wherein the PGU further comprises a real time protocol logical unit (RTPU) for generating the primary data chunks and the secondary data chunks according to a communication standard.

4. The system of claim 1, wherein the PGU further comprises a packet delivery unit (PDU) for adding identification data to each primary data chunk and secondary data chunk, each associated primary-secondary data chunk pair having identical identification data.

5. The system of claim 4, wherein the identification data comprises at least one type of data from a group consisting of a sequence number and a time stamp.

6. The system of claim 1, wherein the PGU delays each secondary data chunk with respect to its associated primary data chunk by a period T, the period T derived from a jitter period of the one or more destination nodes.

7. The system of claim 1, wherein the PGU delays each secondary data chunk with respect to its associated primary data chunk by an integer number of primary data chunks.

8. The system of claim 1, wherein the PGU delivers each primary data chunk as a primary packet and each delayed secondary data chunk as a secondary packet to the network controller for transmission to the one or more destination nodes.

9. The system of claim 8, wherein the one or more destination nodes process each delayed secondary packet if an associated primary packet is not received.

10. The system of claim 1, wherein the PGU builds a compound packet from a primary data chunk and a non-associated delayed secondary data chunk, and delivers the compound packet to the network controller for transmission to the one or more destination nodes.

11. The system of claim 10, wherein the one or more destination nodes are configured to process a secondary data chunk of a second compound packet if a first compound packet with an associated primary data chunk is not received.

12. The system of claim 1, wherein the PGU and the network controller are comprised within an endpoint.

13. The system of claim 1, wherein the PGU and the network controller are comprised within a multipoint control unit.

14. The system of claim 1, wherein the PGU and the network controller are comprised within a multimedia gateway.

15. The system of claim 1, wherein each secondary data chunk comprises at least one type of data from a group consisting of a frame header, a GOB header, a slice header, a modified macro block header, an Intra MB, and macro blocks having only motion vector data.

16. The system of claim 1, wherein the PGU generates the secondary data chunks if a packet loss rate as measured at the one or more destination nodes exceeds a predefined threshold value.

17. The system of claim 3, wherein the communication standard is H.323.

18. The system of claim 3, wherein the communication standard is SIP.

19. The system of claim 1, wherein the compressed video stream is compressed according to the H.261 compression standard.

20. The system of claim 1, wherein the compressed video stream is compressed according to the H.263 compression standard.

21. A method for improving quality of video communication, comprising the steps of:

receiving a compressed video stream, the compressed video stream having a plurality of fields;

parsing the plurality of fields from the compressed video stream and determining field types;

generating secondary data chunks and primary data chunks based on the field types, each secondary data chunk associated with a primary data chunk;

delaying each secondary data chunk with respect to its associated primary data chunk;

generating packets from the delayed secondary data chunks and primary data chunks; and

sending the packets to one or more destination nodes,

wherein each secondary data chunk contains data corresponding to at least a portion of a video frame covered by the corresponding primary data chunk, and

wherein the secondary data chunk is delayed such that it arrives at the one or more destination nodes after the associated primary data chunk but before a declaration by the one or more destination nodes that the associated primary data chunk is lost.

22. The method of claim 21, wherein video data included in each secondary data chunk and video data included in each associated primary data chunk cover a same portion of a video frame.

23. The method of claim 21, further comprising the step of adding identification data to each primary data chunk and secondary data chunk, each associated primary-secondary data chunk pair having identical identification data.

24. The method of claim 21, wherein the step of generating packets from the delayed secondary data chunks and primary data chunks further comprises the step of generating a secondary packet from each delayed secondary data chunk and a primary packet from each primary data chunk, each secondary packet associated with a primary packet.

25. The method of claim 24, further comprising the step of processing the secondary packet for use in video communication if the associated primary packet is not received by the one or more destination nodes.

26. The method of claim 21, wherein the step of generating packets from the delayed secondary data chunks and primary data chunks further comprises the step of building a compound packet from a primary data chunk and a delayed secondary data chunk, the delayed secondary data chunk not associated with the primary data chunk.

27. The method of claim 26, wherein the one or more destination nodes are configured to process a delayed secondary data chunk of a second compound packet if a first compound packet with an associated primary data chunk is not received.

28. The method of claim 21, wherein the step of parsing the plurality of fields further comprises the steps of:

synchronizing on a Picture Start Code (PSC) field from the compressed video stream; and

parsing fields subsequent to the PSC field for field type.

29. The method of claim 21, wherein the step of generating secondary data chunks and primary data chunks based on the field type further comprises executing an MB module for generating the secondary and primary data chunks, if the field type is a MB field.

30. The method of claim 21, wherein the step of generating secondary data chunks and primary data chunks based on the field type further comprises executing a frame header module for generating the secondary and primary data chunks, if the field type is a picture header field.

31. The method of claim 21, wherein the step of generating secondary data chunks and primary data chunks based on the field type further comprises executing a GOB/slice header module for generating the secondary and primary data chunks, if the field type is a GOB or slice header field.

32. The method of claim 21, wherein the step of generating secondary data chunks and primary data chunks based on the field type further comprises generating secondary data chunks only if a packet loss rate as measured at the one or more destination nodes exceeds a predefined threshold value.

33. An electronic-readable medium having embodied thereon a program, the program being executable by a machine to perform method steps for improving quality of video communication, the method steps comprising:

receiving a compressed video stream, the compressed video stream having a plurality of fields;

parsing the plurality of fields from the compressed video stream and determining field types;

generating secondary data chunks and primary data chunks based on the field types, each secondary data chunk associated with a primary data chunk;

delaying each secondary data chunk with respect to its associated primary data chunk;

generating packets from the delayed secondary data chunks and primary data chunks; and

sending the packets to one or more destination nodes,

wherein each secondary data chunk contains data corresponding to at least a portion of a video frame covered by the corresponding primary data chunk, and

wherein the secondary data chunk is delayed such that the packet generated from a secondary data chunk arrives at the one or more destination nodes after the packet generated from the associated primary data chunk but before a declaration by the one or more destination nodes that the packet generated from the associated primary data chunk is lost.

34. The electronic-readable medium of claim 33, further comprising the step of adding identification data to each primary data chunk and secondary data chunk, each associated primary-secondary data chunk pair having identical identification data.

35. The electronic-readable medium of claim 33, wherein the step of generating packets from the delayed secondary data chunks and primary data chunks further comprises the step of generating a secondary packet from each delayed secondary data chunk and a primary packet from each primary data chunk, each secondary packet associated with a primary packet.

36. The electronic-readable medium of claim 35, further comprising the step of processing the secondary packet for use in video communication if the associated primary packet is not received by the one or more destination nodes.

37. The electronic-readable medium of claim 33, wherein the step of generating packets from the delayed secondary data chunks and primary data chunks further comprises the step of building a compound packet from a primary data chunk and a delayed secondary data chunk, the delayed secondary data chunk not associated with the primary data chunk.

38. The electronic-readable medium of claim 37, wherein the one or more destination nodes are configured to process a delayed secondary data chunk of a second compound packet if a first compound packet with an associated primary data chunk is not received.

39. The electronic-readable medium of claim 33, wherein the step of generating secondary data chunks and primary data chunks based on the field type further comprises generating secondary data chunks only if a packet loss rate as measured at the one or more destination nodes exceeds a predefined threshold value.

40. A system for improving quality of video communication, comprising:

means for receiving a compressed video stream, the compressed video stream having a plurality of fields;

means for parsing the plurality of fields from the compressed video stream and determining field types;

means for generating secondary data chunks and primary data chunks based on the field types, each secondary data chunk associated with a primary data chunk;

means for delaying each secondary data chunk with respect to its associated primary data chunk;

means for generating packets from the delayed secondary data chunks and primary data chunks; and

means for sending the packets to one or more destination nodes,

wherein each secondary data chunk contains data corresponding to at least a portion of a video frame covered by the corresponding primary data chunk, and

wherein the secondary data chunk is delayed such that it arrives at the one or more destination nodes after the associated primary data chunk but before a declaration by the one or more destination nodes that the associated primary data chunk is lost.