Active stream format for holding multiple media streams

• US 20050058133A1
• Filed: 10/28/2004
• Published: 03/17/2005
• Est. Priority Date: 03/08/1996
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Knowlton, Chadd B., VanAntwerp, Mark D., Levi, Steven P., Dowell, Craig M.
• Granted Patent: US 7,466,721 B2
• Time in Patent Office: Days
• US Class Current: 370/389
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04L 69/326 in the transport layer [OSI layer 4] H04L69/16 takes precedence
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04N 7/52 Systems for transmission of a pulse code modulated video signal with one or more other pulse code modulated signals, e.g. an audio signal or a synchronizing signal assembling of a multiplex stream by combining a video stream with other content or additional data, remultiplexing of multiplex streams, insertion of stuffing bits into the multiplex stream, assembling of a packetised elementary stream at server side H04N21/236; disassembling of a multiplex stream, remultiplexing of multiplex streams, extraction or processing of Service Information, disassembling of packetised elementary stream at client side H04N21/434

Abstract

An active stream format is defined and adopted for a logical structure that encapsulates multiple data streams. The data streams may be of different media. The data of the data streams is partitioned into packets that are suitable for transmission over a transport medium. The packets may include error correcting information. The packets may also include clock licenses for dictating the advancement of a clock when the data streams are rendered. The format of ASF facilitates flexibility and choice of packet size and in specifying maximum bit rate at which data may be rendered. Error concealment strategies may be employed in the packetization of data to distribute portions of samples to multiple packets. Property information may be replicated and stored in separate packets to enhance its error tolerance. The format facilitates dynamic definition of media types and the packetization of data in such dynamically defined data types within the format.

Claims

1. One or more computer readable media comprising computer executable instructions that, when executed on a computer, cause the computer to perform the steps of:

providing a logical structure for encapsulating multiple streams of data;

wherein;

said streams of data are stored in packets; and

the logical structure holds a field for a maximum packet size and a field for a minimum packet size;

storing clock licenses that dictate advancement of a clock in multiple ones of the packets;

transmitting the logical structure from the source computer to the destination computer; and

for each packet that holds a clock license, advancing the clock at the destination computer as dictated by the clock license in response to receiving the packet at the destination computer.

2. One or more computer readable media of claim 1, wherein each clock license includes a time value to which the clock at the destination computer is to be advanced.

3. One or more computer readable media of claim 1, wherein each clock license includes an expiration time after which the clock license is invalid.

4. One or more computer readable media of claim 1, wherein the multiple streams of data in the logical structure are Active Stream Format (ASF) data streams.

5. One or more computer readable media of claim 1, wherein the logical structure holds a field for a maximum bit rate at which the multiple streams of data may be rendered at the destination.

6. One or more computer readable media of claim 1, wherein:

the logical structure holds a field for a new media type; and

the steps include accessing the field that identifies the new media type, upon receipt of the logical structure by the destination computer to determine a renderer to use to render data of the media type.

7. A system comprising a logical structure that encapsulates:

multiple streams of data wherein the streams of data are stored in packets;

clock licenses that each dictate advancement of a clock that regulates rendering of the data in the packets; and

a field in the logical structure for holding a value that specifies a maximum bit rate at which the multiple streams of data may be rendered.

8. The system of claim 7 wherein each clock license includes a time value to which the clock at the destination computer is to be advanced.

9. The system of claim 7 wherein each clock license includes an expiration time after which the clock license is invalid.

10. The system of claim 7, wherein the logical structure that encapsulates components further comprises a maximum packet size and a minimum packet size

11. The system of claim 7, wherein the multiple streams of data in the logical structure are Active Stream Format (ASF) data streams.

12. The system of claim 7, wherein:

the streams of data stored in packets are of a new media type; and

the new media type can be used to determine a renderer to use to render data of the new media type.

13. A computer comprising:

storage; and

a logical structure stored in the storage for encapsulating multiple data streams, data from said data streams being incorporated in packets, wherein;

the data stored in the packets are of a new media type;

the logical structure stores an identifier for the new media type; and

the identifier can be used to determine a renderer to use to render data of the new media type; and

a clock license being encapsulated into at least one packet for advancing a clock at a destination when processed at the destination.

14. The computer of claim 13, wherein the logical structure holds a field for a maximum packet size and a field for a minimum packet size.

15. The computer of claim 13, wherein the multiple streams of data in the logical structure are Active Stream Format (ASF) data streams.

16. The computer of claim 13, wherein the logical structure holds a value that specifies a maximum bit rate at which the multiple streams of data may be rendered.

17. A system comprising:

means for providing a logical structure for encapsulating multiple streams of data, said streams of data being stored in packets, by;

storing samples of data from multiple data streams in the packets;

storing replicas of information in at least some of the packets;

storing error correcting data in the at least some of the packets, wherein the error correcting data identifies an error correcting method for the at least some of the packets;

setting a flag in the packets that hold the replicas;

storing in the logical structure a field for a maximum packet size and a field for a minimum packet size; and

encapsulating the packets into the logical structure, wherein at least some of the packets hold the replicas;

storing clock licenses that dictate advancement of a clock in multiple ones of the packets;

transmitting the packets of the logical structure on a packet-by-packet basis over a packet switched network from the source computer to the destination computer; and

for each packet that holds a clock license, advancing the clock at the destination computer as dictated by the clock license in response to receiving the packet at the destination computer.

18. The system as defined in claim 17, wherein the replicas of information hold property information regarding the samples of data.

19. The system of claim 17 wherein portions of a sample are stored in selected packets and a replica of property information regarding the sample is stored in each packet in which a portion of the sample is stored.

20. The system of claim 17, further comprising the step of examining one of the replicas of information at the destination computer when one of the packets is lost during the transmitting.

21. The system of claim 17, further comprising using the error correcting data in the at least some of the packets to correct an error when the transmitted logical structure is received at the destination.

22. The system as defined in claim 17, wherein the multiple streams of data in the logical structure are Active Stream Format (ASF) data streams.

23. The system of claim 17, wherein:

the logical structure includes a header section and a data section; and

the error correcting data is stored in multiple packets in the data section.

24. The system of claim 23, wherein information in the header section of the logical structure indicates what error correcting methodology is used with the error correcting data stored in the multiple packets in the data section.

25. The system of claim 23, wherein the header section holds information regarding multiple error correcting methods.

26. The system of claim 23, wherein the error correcting data identifies one of a plurality of error correcting methods.

27. The system of claim 23, wherein the error correcting data holds parity bits.

28. A computer-readable storage medium comprising a logical structure that encapsulates components that include:

multiple streams of data wherein the streams of data are stored in packets;

a field in the logical structure that holds a value that specifies a maximum bit rate at which the multiple streams of data may be rendered; and

clock licenses that each dictate advancement of a clock that regulates rendering of the data in the packets, wherein;

the streams of data stored in the packets are samples of data from multiple data streams in packets for transmission on a packet-by-packet basis over a packet switched network;

replicas of information are stored in at least some of the packets;

error correcting data is stored in the at least some of the packets;

the error correcting data identifies an error correcting method for the at least some of the packets; and

a flag is stored in each said packet that holds the replicas.

29. The computer-readable storage medium of claim 28 wherein portions of a sample are stored in selected packets and a replica of property information regarding the sample is stored in each packet in which a portion of the sample is stored.

30. The computer-readable storage medium as defined in claim 28, wherein:

the logical structure includes a header section and a data section, and the error correcting data is stored in multiple packets in the data section.

31. The computer-readable storage medium as defined in claim 30, wherein the information in the header section of the logical structure indicates what error correcting methodology is used with the error correcting data stored in the multiple packets in the data section.

32. The computer-readable storage medium as defined in claim 30, wherein the header section holds information regarding multiple error correcting methods.

33. The computer-readable storage medium as defined in claim 30, wherein the error correcting data identifies a plurality of error correcting methods.

34. The computer-readable storage medium as defined in claim 30, wherein the error correcting data holds parity bits.

35. The computer-readable storage medium as defined in claim 30, wherein the logical structure that encapsulates components further comprises a field for a maximum packet size and a field for a minimum packet size.

36. The computer-readable storage medium as defined in claim 30, wherein the multiple streams of data in the logical structure are Active Stream Format (ASF) data streams.

37. The computer-readable storage medium as defined in claim 30, wherein:

the logical structure that encapsulates components further comprises a field for a new media type for the streams of data stored in the packets; and

the new media type identifies a renderer to use to render data of the new media type.

38. The computer-readable storage medium as defined in claim 30, wherein:

the logical structure that encapsulates components further comprises;

a field for a maximum packet size and a field for a minimum packet size; and

a field for a new media type for the streams of data stored in the packets the multiple streams of data in the logical structure are Active Stream Format (ASF) data streams; and

the new media type identifies a renderer to use to render data of the new media type.

39. A computer comprising:

storage; and

a logical structure stored in the storage for encapsulating multiple data streams, data from said data streams being of a new media type and incorporated in packets, wherein the logical structure includes an identifier of the new media type from which a renderer can be determined to render the data of the new media type; and

a clock license being encapsulated into at least one packet for advancing a clock at a destination when processed at the destination, wherein;

the streams of data stored in the packets are samples of data from multiple data streams in the packets for transmission on a packet-by-packet basis over a packet switched network;

replicas of information are stored in at least some of the packets;

error correcting data is stored in the at least some of the packets;

the error correcting data identifies an error correcting method for the at least some of the packets; and

a flag is stored in each said packet that holds the replicas.

40. A computer comprising:

storage;

a logical structure stored in the storage for encapsulating multiple data streams, wherein;

the data from said data streams is incorporated in packets; and

the multiple streams of data in the logical structure are Active Stream Format (ASF) data streams; and

a clock license being encapsulated into at least one packet for advancing a clock at a destination when processed at the destination, wherein portions of a sample are stored in selected packets and a replica of property information regarding the sample is stored in each packet in which a portion of the sample is stored.

41. The computer of claim 40, wherein:

the logical structure includes a header section and a data section, and

the error correcting data is stored in multiple packets in the data section.

42. The computer of claim 41, wherein information in the header section of the logical structure indicates what error correcting methodology is used with the error correcting data stored in the multiple packets in the data section.

43. The data processing system as defined in claim 41, wherein the header section holds information regarding multiple error correcting methods.

44. The computer of claim 41, wherein the error correcting data identifies a plurality of error correcting methods.

45. The computer of claim 41, wherein the error correcting data holds parity bits.

46. The computer of claim 41, wherein the logical structure includes a field for a maximum packet size and a field for a minimum packet size.

47. The computer of claim 41, wherein the multiple streams of data in the logical structure are Active Stream Format (ASF) data streams.

48. The computer of claim 41, wherein the logical structure includes a field for holding a value that specifies a maximum bit rate at which the multiple streams of data may be rendered.

49. The data processing system as defined in claim 41, wherein the logical structure includes a field for an identifier of a new media type for the data from said data streams incorporated in the packets and from which a renderer can be determined to render the data of the new media type.