LOSSLESS DATA CODING FOR BIDIRECTIONAL COMMUNICATION IN A COLLABORATIVE SESSION OF MULTIMEDIA CONTENT EXCHANGE

• US 20140219295A1
• Filed: 03/01/2012
• Published: 08/07/2014
• Est. Priority Date: 03/03/2011
• Status: Active Grant

• Current Assignee: Institut Mines-Télécom, Prologue Co.
• Original Assignee: Institut Mines-Télécom, Prologue Co.
• Inventors: Joveski, Bojan, Gardenghi, Ludovico, Marshall, James Iain, Mitrea, Petru Mihai, Preteux, Jacqueline Franoise
• Granted Patent: US 9,584,576 B2
• Time in Patent Office: Days
• US Class Current: 370/477
• CPC Class Codes: H03M 7/3088 employing the use of a dictionary, e.g. LZ78
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/4038 with floor control
• CPC Class Codes: H04L 65/65 Network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP]
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04N 21/643 Communication protocols network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP], H04L65/65

Abstract

The disclosed method for coding data includes the exchange between the transmitter and the receiver, in the course of the session, of attributes of collaboration messages that are able to be used in said session and of indices associated with these attributes. In various implementations, the attributes and their indices may be used by these pieces of equipment for updating a shared dictionary of indexed attributes. Upon coding, the attributes of the collaboration messages may be substituted with their indices; and upon decoding, the inverse operation may be carried out. The shared dictionaries may be destroyed at the end of the session.

Claims

1. A method for lossless data coding applied by a piece of transmitter equipment, in bidirectional communication with at least one piece of receiver equipment in a collaborative session of exchange of multimedia contents, this method including:

during said session, at least;

one step for exchanging, with said at least one piece of receiver equipment, at least one attribute of a collaboration message which may be used in said session and an index associated with this attribute, said attribute and its index being used by said equipment for updating a shared dictionary of indexed attributes, this dictionary being stored in memory by each of said pieces of equipment during the whole duration of the session;

one step for substituting, in a collaboration message intended to be sent to said at least one piece of receiver equipment, at least one attribute with its index in said shared dictionary;

one step for sending said collaboration message to said at least one piece of receiver equipment; and

one step for destroying said shared dictionary at the end of said session.

2. The data coding method according to claim 1, wherein the size of said attribute is greater than the size of its index in said shared dictionary.

11. A computer program including instructions for executing the steps of a coding method according to claim 1 when said program is executed by a computer.

12. A non-transitory computer-legible recording medium on which a computer program is recorded, comprising instructions for executing the steps of a coding method according to claim 1.

20. The method according to claim 1, wherein said collaboration message is of four possible natures selected from:

a listing message for said updating of the shared dictionary of indexed attributes during the session;

a message specifying a state of presence of said piece of transmitter equipment;

a message including pieces of information intended for the piece of receiver equipment; and

a message, including metadata for administration or control of a collaboration system, in which said system is applied.

21. The method according to claim 20, wherein said collaboration message includes:

a field representative of said nature, and for the collaboration messages other than said listing messages;

an attribute representative of the semantics of said nature; and

a binary element representative of the presence or not of said attribute in said message, followed, when said attribute is present, by a body including the index associated with said attribute in said shared dictionary.

22. The method according to claim 1, wherein said collaborative session is compliant with the XMPP standard.

23. The method according to claim 1, wherein said multimedia contents are compliant with a standard of the MPEG family, said session applying the RTP protocol for the exchange of said multimedia contents and the RTSP protocol for the initialization and control of this exchange.

3. A method for decoding data applied by a piece of receiver equipment, in bidirectional communication with at least one piece of transmitter equipment in a collaborative session of exchange of multimedia contents, this method including:

during said session, at least;

one step for exchanging, with said at least one piece of transmitter equipment, at least one attribute of a collaboration message which may be used in said session and an index associated with this attribute, said attribute and its index being used by said equipment for updating a shared dictionary of index attributes, this dictionary being stored in memory by each of said pieces of equipment during the whole duration of the session; and

one step for receiving a collaboration message transmitted by a so-called piece of transmitter equipment including at least one index;

one step for substituting, in said collaboration message said at least one index with the attribute with which it is associated in said shared dictionary; and

one step for destroying said shared dictionary at the end of said session.

4. The method according to claim 3, wherein said collaboration message is of four possible natures selected from;

a listing message for said updating of the shared dictionary of indexed attributes during the session;

a message specifying a state of presence of said piece of transmitter equipment;

a message including pieces of information intended for the piece of receiver equipment; and

a message, including metadata for administration or control of a collaboration system, in which said system is applied.

5. The method according to claim 4, wherein said collaboration message includes:

a field representative of said nature, and for the collaboration messages other than said listing messages;

an attribute representative of the semantics of said nature; and

a binary element representative of the presence or not of said attribute in said message, followed, when said attribute is present, by a body including the index associated with said attribute in said shared dictionary.

6. The method according to claim 3, wherein said collaborative session is compliant with the XMPP standard.

7. The method according to claim 3, wherein said multimedia contents are compliant with a standard of the MPEG family, said session applying the RTP protocol for the exchange of said multimedia contents and the RTSP protocol for the initialization and control of this exchange.

16. A computer program including instructions for executing the steps of a decoding method according to claim 3 when said program is executed by a computer.

17. A non-transitory computer-legible recording medium on which a computer program is recorded, comprising instructions for executing the steps of a decoding method according to claim 3.

8. A lossless data coding device which may be incorporated into a piece of transmitter equipment capable of establishing a bidirectional communication with at least one piece of receiver equipment in a collaborative session of exchange of multimedia contents, this device including:

means for exchanging with said at least one piece of receiver equipment, during said session, at least one attribute of a collaboration message which may be used in said session and an index associated with this attribute, said attribute and its index being used by said pieces of equipment for updating a shared dictionary of indexed attributes;

means for storing in memory said shared dictionary for the whole duration of the session;

means for substituting, in a collaboration message intended to be sent to said at least one piece of receiver equipment, at least one attribute with its index in said shared dictionary;

means for sending said collaboration message to said at least one piece of receiver equipment; and

means for destroying said shared dictionary at the end of said session,

10. A communication device including a coding device according to claim 8.

13. Communication equipment including a device according to claim 10.

14. A collaboration system including at least one piece of equipment according to claim 13.

19. The collaboration system of claim 14, further including at least one piece of equipment according to claim 18.

9. A data decoding device which may be incorporated in a piece of receiver equipment capable of establishing a bidirectional communication with at least one piece of transmitter equipment in a collaborative session of exchange of multimedia contents, this device including:

means for exchanging with said at least one piece of transmitter equipment, during said session, at least one attribute of a collaboration message which may be used in said session and an index associated with this attribute, said attribute and its index being used by said pieces of equipment for updating a shared dictionary of indexed attributes;

means for receiving a collaboration message transmitted by a so-called piece of transmitter equipment including at least one index;

means for substituting, in said collaboration message, said at least one index with the attribute with which it is associated in said shared dictionary; and

means for destroying said shared dictionary at the, end of said session.

15. A communication device including a decoding device according to claim 9.

18. Communication equipment including a device according to claim 15.