Programmable video recorder backing store for non-byte stream formats

• US 7,379,654 B2
• Filed: 06/19/2002
• Issued: 05/27/2008
• Est. Priority Date: 06/19/2002
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Gates, Matthijs Arjan, Sankaranarayan, Mukund, Srinivasan, Jai, Chakrabarti, Alok, Ferriere, Philippe
• Primary Examiner(s): Tran; Thai Q.
• Assistant Examiner(s): Hasan; Syed Y.
• Application Number:
  US10/175,208
• Publication Number:
  US 20030235391A1
• Time in Patent Office: 2,169 Days
• Field of Search: 386/4, 386/33, 386/40, 386/45, 386/46, 386/48, 386/52, 386/68, 386/83, 386/92, 386/105, 386/106, 386/109, 386/112, 386/125, 386/126, 369/60.01, 348/512, 348/513, 348/571, 348/714, 725/48, 725/39, 725/55, 725/56, 725/92, 725/89, 725/134, 725/142, 525/115
• US Class Current: 386/326
• 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. A method implemented in a computing system that receives streamed data comprising data samples from a streamed data source, and wherein the computing system includes a buffering store for temporarily storing the streamed data as it is received, and which is independent of a recording store configured to persistently store the streamed data upon receiving a record command from a user, the method, configuring and using the temporary buffering store to store the streamed data as it is received, wherein the method comprises:

prior to receiving the streamed data, specifying a total duration of content the buffering store is configured to temporarily store;

configuring the buffering store to include a plurality of separately identifiable files for storing the content;

prior to receiving the streamed data, specifying, for each of the plurality of files, a duration of the content each of the plurality of files in the buffering store is permitted to hold, rather than specifying the size of each file in terms of byte size, wherein the duration of content that each of the plurality of files is configured to hold is substantially the same for each of the plurality of files;

as streamed data is received, writing data samples of the streamed data into a first file of the buffering store until the duration of the first file is reached and then writing additional data samples to each subsequent file in the buffering store, one file at a time, until the duration of each subsequent file is reached; and

once the duration of each file in the buffering store is reached, removing data samples written to the first file of the buffering store and replacing the removed data samples with newly received data samples of the streamed data.

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

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

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

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

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

7. 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.

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

9. A method as recited in claim 8, wherein the number of files is changed by at least one of user input and a policy agent.

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

11. 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.

12. 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.

13. 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.

14. 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.

15. A method as recited in claim 1, including the act of expanding the buffering 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.

16. 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.

17. A method as recited in claim 16, 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.

18. A method as recited in claim 1, wherein the computing system includes a reader configured to access and read the data samples from the buffering 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.

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

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

21. A method as recited in claim 1, wherein the buffering store includes a backing store configured to store temporary files.

22. A method as recited in claim 21, wherein the buffering store includes a recording store configured to store permanent files.

28. A method as recited in claim 1, wherein the buffering store further includes a recording store configured to store permanent files.

29. A method as recited in claim 28, wherein the total number of files is at least two, and wherein at least one file is a temporary file.

30. A method as recited in claim 29, wherein the streamed data is formatted in a non-byte steam format.

31. A method as recited in claim 30, wherein the streamed data includes ASF formatted data.

32. A method as recited in claim 28, wherein each file is formatted in a non-byte stream format.

33. A method as recited in claim 28, wherein the duration of each file is at least 5 minutes.

34. A method as recited in claim 28, wherein the duration of each file is 10 minutes.

35. A method as recited in claim 1, wherein replacing the removed data samples includes replacing the first file with a new file in the buffering store and wherein removing data samples written to the first file includes removing all data samples written to the first file.

36. A method as recited in claim 1, wherein replacing the removed data samples includes replacing only some of the data samples written to the first file with the newly received data samples.

37. A method as recited in claim 1, wherein replacing the removed data samples occurs only after first adding a new temporary file to the buffering store that causes the buffering store to exceed the total duration of content specified for the buffering store, and only after first writing new data samples to the new temporary file.

38. A method as recited in claim 37, wherein the new temporary file is only created upon determining that a reader is reading the first file at a time when the duration of each file in the buffering store is reached.

39. A method as recited in claim 1, wherein the method further includes, upon receiving a record command from a user, recording at least some of the received data samples to a separate recording store.

23. A computer-readable storage media storing computer-executable instructions for implementing a method in a computing system that receives streamed data comprising data samples from a streamed data source, and wherein the computing system includes a buffering store for temporarily storing the streamed data as it is received, and which is independent of a recording store configured to persistently store the streamed data upon receiving a record command from a user, the method configuring and using the temporary buffering store to store the streamed data as it is received, the method further comprising:

prior to receiving the streamed data, specifying a total duration of content the buffering store is configured to temporarily store;

configuring the buffering store to include a plurality of separately identifiable files for storing the content;

prior to receiving the streamed data, specifying, for each of the plurality of files, a duration of the content each of the plurality of files in the buffering store is permitted to hold, rather than specifying the size of each file in terms of byte size, wherein the duration of content that each of the plurality of files is configured to hold is substantially the same for each of the plurality of files;

as streamed data is received, writing data samples of the streamed data into a first file of the buffering store until the duration of the first file is reached and then writing additional data samples to each subsequent file in the buffering store, one file at a time, until the duration of each subsequent file is reached; and

once the duration of each file in the buffering store is reached, removing data samples written to the first file of the buffering store and replacing the removed data samples with newly received data samples of the streamed data.

24. The computer-readable storage media as recited in claim 23, wherein the one or more computer-readable media include system memory.

25. The computer-readable storage media as recited in claim 23, wherein the streamed data comprises at least one of ASF streamed data and MPEG data.

26. The computer-readable storage media as recited in claim 23, wherein each of the files is formatted in a non-byte stream format.

27. The computer-readable storage media as recited in claim 23, 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.

40. A method implemented in a computing system that receives streamed data comprising data samples from a streamed data source, and wherein the computing system includes a buffering store for temporarily storing the streamed data as it is received, and which is independent of a recording store configured to persistently store the streamed data upon receiving a record command from a user, the method, configuring and using the temporary buffering store to store the streamed data as it is received, wherein the method comprises:

prior to receiving the streamed data, specifying a total number of files to be used in the buffering store, the total number of files comprising a plurality of files;

specifying, for each of the plurality of files, a duration of the streamed data content each file of the plurality of files in the buffering store is permitted to hold, rather than specifying the size of each file in terms of byte size, the duration of the streamed data content that each file of the plurality of files is configured to hold being substantially the same and being received prior to the receipt of the streamed data;

as the streamed data is received and until the duration of each file the buffering 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 and corresponding file; and

upon determining that the time stamp of the new data sample does not correspond to a duration of any existing file in the buffering store, and upon determining the total number of files existing in the buffering store is less than the specified total number of files, opening a new file in the buffering store and specifying a 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; and

wherein once the specified duration of each of the total number of files specified in the buffering 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; and

writing the data sample to the new temporary file.

41. A method as recited in claim 40, wherein upon determining the reader is reading from the oldest temporary file in the buffering store and that the specified duration of each of the total number of files specified in the buffering store is reached, the method further includes the acts of:

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 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.

42. A method as recited in claim 41, wherein the determination that additional memory from the storage medium can be allocated to the buffering store is derived from at least one of a predetermined size of the buffering store and an external policy agent.

43. A method as recited in claim 41, wherein upon determining the reader is reading from the oldest temporary file in the buffering store and that the specified duration of each of the total number of files specified in the buffering store is reached, 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 buffering store;

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

overwriting the oldest temporary file with a new temporary file; and

writing the new data sample to the new temporary file.

44. A method as recited in claim 40, wherein the streamed data includes non-byte streamed data samples.

45. A method as recited in claim 40, wherein each file in the buffering store is formatted in a non-byte stream format.

46. A method as recited in claim 40, wherein upon determining the reader is reading from the oldest temporary file in the buffering store and that the specified duration of each of the total number of files specified in the buffering store is reached, and wherein the file format of each file in the buffering 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 buffering 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.

47. A method as recited in claim 46, wherein the streamed data includes data samples encoded by an MPEG format.