Programmable video recorder backing store for non-byte stream formats

• US 20030235391A1
• Filed: 06/19/2002
• Published: 12/25/2003
• Est. Priority Date: 06/19/2002
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Sankaranarayan, Mukund, Srinivasan, Jai, Chakrabarti, Alok, Ferriere, Philippe, Gates, Matthijs Arjan
• Granted Patent: US 7,379,654 B2
• Time in Patent Office: Days
• US Class Current: 386/295
• CPC Class Codes: H04N 5/76 Television signal recording
• CPC Class Codes: H04N 5/775 between a recording apparatus and a television receiver
• CPC Class Codes: H04N 9/8042 involving data reduction

Abstract

The buffer of a programmable video recorder includes a backing store having a plurality of discrete temporary files that are configured to store non-byte streamed data, such as ASF data. The data stream includes a number of data samples that are each assigned a time stamp upon receipt. Each data sample is then assigned and written to a temporary file based on a corresponding duration assigned to each of the temporary files. The backing store operates like a moving window as the oldest temporary files are replaced with the newest temporary files.

Claims

1. In a computing system that receives streamed data comprising data samples from a streamed data source, and wherein the computing system includes a storage medium and a processor for configuring a portion of the storage medium as a PVR store for storing the streamed data as it is received, a method for configuring the PVR store as a moving window so that the streamed data is capable of being stored in a file format independent of any particular file format otherwise dictated by the streamed data as received, comprising the acts of:

prior to receiving the streamed data, specifying a window defined by a number of files permitted to be used in the PVR store, wherein each file utilizes a standard file format that is independent of the file format otherwise dictated by the streamed data as received;

specifying a duration of the streamed data content each file of the PVR store is permitted to hold, rather than specifying the size of each file in terms of byte size;

as the streamed data is received, writing data samples into a first file of the PVR store until the duration of the first file is reached; and

once the duration of each permitted file is reached, moving the window by removing any data samples written to the first file of the PVR store, and then creating a storage location within the window into which additional data samples of the streamed data continue to be written.

2. A method as recited in claim 1, wherein the act of specifying a window includes the act of specifying a window defined by a number of temporary files permitted to be used in a backing store of the PVR store, wherein the backing store of the PVR store is configured to store temporary files.

3. A method as recited in claim 1, wherein the act of specifying a window includes the act of specifying a window defined by a number of permanent files permitted to be used in a recording store of the PVR store, wherein the recording store of the PVR store is configured to store permanent files.

4. A method as recited in claim 1, wherein the streamed data comprises byte stream formatted data.

5. A method as recited in claim 1, wherein the streamed data is ASF formatted.

6. A method as recited in claim 1, wherein the streamed data includes data samples encoded by an MPEG format.

7. A method as recited in claim 1, wherein the files of the PVR store are formatted in a byte stream format.

8. A method as recited in claim 1, wherein the files of the PVR store are formatted in an ASF format.

9. A method as recited in claim 1, wherein the act of specifying a duration of the streamed data to each file includes the act of assigning sequential durations of content each of the files is permitted to hold.

10. A method as recited in claim 1, wherein the number of files is a predetermined default number of files.

11. A method as recited in claim 10, wherein the number of files and the duration assigned to each file is determined prior to the act of receiving streamed data.

12. A method as recited in claim 10, wherein the number of files is changed by at least one of user input and a policy agent.

13. A method as recited in claim 1, wherein the number of files changes dynamically to accommodate newly received streamed data.

14. A method as recited in claim 1, wherein the duration of streamed data content each file is permitted to hold changes according to at least one of user input and a policy agent.

15. A method as recited in claim 1, wherein prior to writing data samples into a first file, the method includes the act of assigning a time stamp to each of the data samples and the act of determining the time stamp assigned to each of the data samples corresponds to the duration specified for the first file.

16. A method as recited in claim 1, wherein the act of removing any data samples written to the first file includes overwriting the first file, and wherein the first file is a temporary file.

17. A method as recited in claim 1, wherein the act of removing any data samples written to the first file includes invalidating the first file and creating a new file to take its place in the window.

18. A method as recited in claim 1, including the act of expanding the window of the PVR store to include at least one file in a recording store, and including the act of writing at least some of the streamed data to the file in the recording store.

19. A method as recited in claim 1, further including the act of creating a notice whenever the data samples are either removed or about to be removed and a reader associated with the computing system is reading from a file containing the data samples.

20. A method as recited in claim 19, further including the act of advancing the reader to read from another file whenever the data samples are about to be removed from the file the reader is reading.

21. A method as recited in claim 1, wherein the computing system includes a reader configured to access and read the data samples from the PVR store, and wherein the method further includes the act of accessing at least one data sample from the first file with the reader based on a time stamp assigned to the data sample.

22. A method as recited in claim 1, wherein the number of files includes more than one file.

23. A method as recited in claim 1, wherein each of the number of files is a temporary file.

24. In a computing system that receives streamed data comprising data samples from a streamed data source, and wherein the computing system includes a storage medium and a processor for configuring a portion of the storage medium as a PVR store for storing the streamed data as it is received, a method for configuring the PVR store as a moving window so that the streamed data is capable of being stored in a file format independent of any particular file format otherwise dictated by the streamed data as received, the method comprising:

the act of, prior to receiving the streamed data, specifying a window defined by a number of files permitted to be used in the PVR store, wherein each file utilizes a standard file format that is independent of the file format otherwise dictated by the streamed data as received;

the act of receiving the data samples of the streamed data;

the act of opening at least one file of the total number of files permitted in the PVR store;

the act of specifying a duration of the streamed data content that at least one file is permitted to hold, rather than specifying the size of the at least one file in terms of byte size;

the step for determining into which of the at least one file new data samples should be written, as each new data sample is received, and until the duration of each permitted file is reached;

the act of, once the duration of each permitted file is reached, moving the window by removing any data samples written to a first one of the at least one file of the PVR store, and then creating a new file within the window into which the new data samples of the streamed data continue to be written.

25. A method as recited in claim 24, wherein the step for determining into which of the at least one file new data samples should be written includes iteratively performing the acts of:

assigning a time stamp to a new data sample; and

upon determining the time stamp of the new data sample corresponds to the duration specified for the at least one file in the PVR store, determining the new data sample should be written to said at least one file.

26. A method as recited in claim 24, wherein the step for determining into which of the at least one file new data samples should be written includes iteratively performing the acts of:

assigning a time stamp to a new data sample; and

upon determining that the time stamp of the new data sample does not correspond to the duration of the at least one file, opening a new file of the total number of the files permitted the PVR store;

upon opening the new file, specifying a duration of the streamed data content the new file is permitted to hold, rather than specifying a size of the new file in terms of byte size, wherein the duration specified for the new file corresponds with the time stamp assigned to the new data sample;

upon specifying the duration for the new file, determining the new data sample should be written to said new file.

27. A method as recited in claim 24, wherein the act of creating a new file within the window into which the new data samples of the streamed data continue to be written includes iteratively performing the acts of:

assigning a time stamp to a new data sample;

opening a new file that invalidates an oldest file of the PVR store; and

specifying a duration of the streamed data content the new file is permitted to hold, rather than specifying a size of the new file in terms of byte size, wherein the duration specified for the new file corresponds with at least the time stamp assigned to the new data sample; and

writing the new data sample to the new file.

28. A method as recited in claim 27, wherein the data samples include non-byte stream data samples.

29. A method as recited in claim 24, wherein each file has a non-byte stream file format.

30. A method as recited in claim 24, wherein the PVR store includes a backing store configured to store temporary files.

31. A method as recited in claim 30, wherein the PVR store includes a recording store configured to store permanent files.

32. A method as recited in claim 31, wherein each of the total number of files permitted the PVR store includes only temporary files.

33. A computer program product for use in a computing system that receives streamed data comprising data samples from a streamed data source, and wherein the computing system includes a storage medium and a processor for configuring a portion of the storage medium as a PVR store for storing the streamed data as it is received, the computer program product for implementing a method for configuring the PVR store as a moving window so that the streamed data is capable of being stored in a file format independent of any particular file format otherwise dictated by the streamed data as received, the computer program product comprising:

one or more computer-readable media carrying computer-executable instructions, that when executed at the computing system, cause the computing system to perform the method, the method including the acts of;

prior to receiving the streamed data, specifying a window defined by a number of files permitted to be used in the PVR store, wherein each file utilizes a standard file format that is independent of the file format otherwise dictated by the streamed data as received, the number of files permitted including temporary files;

specifying a duration of the streamed data content each file of the PVR store is permitted to hold, rather than specifying the size of each file in terms of byte size;

as the streamed data is received, writing data samples into files of the PVR store until the duration of the files is reached; and

once the duration of each temporary file permitted to be used in the PVR store is reached, moving the window by removing any data samples written to a first temporary file of the PVR store, and then creating a storage location within the window into which additional data samples of the streamed data continue to be written.

34. The computer program product as recited in claim 33, wherein the one or more computer-readable media include system memory.

35. The computer program product as recited in claim 33, wherein the streamed data comprises at least one of ASF streamed data and MPEG data.

36. The computer program product as recited in claim 33, wherein each of the files is formatted in a non-byte stream format.

37. The computer program product as recited in claim 33, wherein the method further includes the act of removing any data samples written to the first temporary file includes the act of overwriting the first temporary file with a new temporary file.

38. In a computing system that receives streamed data comprising data samples from a streamed data source, and wherein the computing system includes a storage medium and a processor for configuring a portion of the storage medium as a PVR for storing the streamed data as it is received, a method for configuring the PVR store as a moving window so that the streamed data is capable of being stored in a file format independent of any particular file format otherwise dictated by the streamed data as received, comprising the acts of:

prior to receiving the streamed data, specifying a window defined by a total number of files to be used in the PVR store, wherein each file utilizes a standard file format that is independent of the file format otherwise dictated by the streamed data as received;

specifying a duration of the streamed data content each file of the PVR store is permitted to hold, rather than specifying the size of each file in terms of byte size;

as the streamed data is received and until the duration of each file the PVR store is permitted to hold is reached, iteratively performing the acts of;

assigning a time stamp to a new data sample of the streamed data;

upon determining the time stamp of the new data sample corresponds to the duration of an existing file, writing the data sample to said existing file; and

upon determining that the time stamp of the new data sample does not correspond to a duration of any existing file, opening a new file and specifying the duration of the streamed data content the new file of the PVR store is permitted to hold and which corresponds with the time stamp assigned to the new data sample, rather than specifying the size of the new file in terms of byte size, and writing the new data sample to the new file; and

wherein the PVR store includes a backing store comprising at least one temporary file, and wherein once the duration of each of the total number of files specified in the PVR store is reached, iteratively performing the acts of;

overwriting an oldest temporary file of the backing store with a new temporary file having a specified duration of the streamed data content the new file of the backing store is permitted to hold and which corresponds with the time stamp assigned to the new data sample, rather than specifying the size of the new temporary file in terms of byte size; and

writing the data sample to the newest temporary file.

39. A method as recited in claim 38, wherein the PVR store farther includes a recording store configured to store permanent files.

40. A method as recited in claim 39, wherein the total number of files is at least two, and wherein at least one file is a temporary file.

41. A method as recited in claim 40, wherein the streamed data is formatted in a non-byte steam format.

42. A method as recited in claim 41, wherein the streamed data includes ASF formatted data.

43. A method as recited in claim 39, wherein each file is formatted in a non-byte stream format.

44. A method as recited in claim 39, wherein the duration of each file is at least 5 minutes.

45. A method as recited in claim 39, wherein the duration of each file is 10 minutes.

46. In a computing system that receives streamed data comprising data samples from a streamed data source, and wherein the computing system includes a storage medium, a processor for configuring a portion of the storage medium as a PVR store for storing the streamed data as it is received and a reader configured to read the streamed data from the storage medium, a method for configuring the PVR store as a moving window so that the streamed data is capable of being stored in a file format independent of any particular file format otherwise dictated by the streamed data as received, the method comprising the acts of:

prior to receiving the streamed data, specifying a window defined by a total number of files to be used in the PVR store, wherein each file utilizes a standard file format that is independent of the file format otherwise dictated by the streamed data as received;

specifying a duration of the streamed data content each file of the PVR store is permitted to hold, rather than specifying the size of each file in terms of byte size;

as the streamed data is received and until the duration of each file the PVR store is permitted to hold is reached, iteratively performing the acts of;

assigning a time stamp to a new data sample of the streamed data;

upon determining the time stamp of the new data sample corresponds to the duration of an existing file that is not being read by the reader, writing the data sample to said existing file; and

upon determining that the time stamp of the new data sample does not correspond to a duration of any existing file, opening a file and specifying the duration of the streamed data content the file is permitted to hold and which corresponds with the time stamp assigned to the new data sample, rather than specifying the size of the file in terms of byte size, and writing the new data sample to the file;

wherein the PVR store includes a backing store comprising at least one temporary file, and

wherein once the duration of each of the total number of files specified in the PVR store is reached, iteratively performing the acts of;

upon determining the reader is not reading from an oldest temporary file in the backing store, overwriting an oldest temporary file with a new temporary file having a specified duration of the streamed data content the new temporary file is permitted to hold and which corresponds with the time stamp assigned to the new data sample, rather than specifying the size of the new temporary file in terms of byte size; and

writing the data sample to the new temporary file.

47. A method as recited in claim 46, wherein upon determining the reader is reading from the oldest temporary file in the PVR store, the method further includes the acts

determining that additional memory from the storage medium can be allocated to the backing store;

opening a new temporary file in the backing store;

specifying the duration of the streamed data content the new temporary file is permitted to hold an d which corresponds with the time stamp assigned to the new data sample, rather than specifying the size of the new temporary file in terms of byte size; and

writing the new data sample to the new temporary file.

48. A method as recited in claim 47, wherein the determination that additional memory from the storage medium can be allocated to the PVR store is derived from at least one of a predetermined size of the PVR store and an external policy agent.

49. A method as recited in claim 47, wherein upon determining the reader is reading from the oldest temporary file in the backing store, and wherein the streamed data is encoded in a non-byte stream format, the method further includes the acts of:

determining that additional memory from the storage medium cannot be allocated to the PVR store;

advancing the reader to read from another file in the PVR store; and

overwriting the oldest temporary file with a new temporary file having a specified duration of the streamed data content the new temporary file is permitted to hold and which corresponds with the time stamp assigned to the new data sample, rather than specifying the size of the new temporary file in terms of byte size; and

writing the new data sample to the new temporary file.

50. A method as recited in claim 46, wherein the streamed data includes non-byte streamed data samples.

51. A method as recited in claim 46, wherein each file in the PVR store is formatted in a non-byte stream format.

52. A method as recited in claim 46, wherein upon determining the reader is reading from the oldest temporary file in the PVR store, and wherein the file format of each file in the PVR store is encoded in a byte stream format, the method further includes the acts of:

determining that additional memory from the storage medium cannot be allocated to the PVR store; and

upon determining that the reader is not reading from an oldest data sample in the oldest temporary file, overwriting the oldest data sample in the oldest temporary file with the new data sample.

53. A method as recited in claim 52, wherein the streamed data includes data samples encoded by an MPEG format.