Method and apparatus for recording data and recovering recorded data

• US 7,155,448 B2
• Filed: 10/13/2004
• Issued: 12/26/2006
• Est. Priority Date: 10/23/2003
• Status: Active Grant

• Current Assignee: Thomson Licensing (Vantiva SA)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Winter, Marco
• Primary Examiner(s): Pardo, Thuy N.
• Application Number:
  US10/963,897
• Publication Number:
  US 20050091280A1
• Time in Patent Office: 804 Days
• Field of Search: 707/202, 707/3, 707/10, 707/101, 707/102, 707/103.R, 707/104.1, 711/4, 386/46, 386/52, 386/69, 386/125
• US Class Current: 711/4
• CPC Class Codes: G11B 27/36 Monitoring, i.e. supervising the progress of recording or reproducing for digital recording G11B20/00 and s.gr.; for monitoring, testing or measuring of TV recorders of the type covered by H04N5/76 and subgroups, see H04N17/06
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing

Abstract

The file system of a hard disk or optical disc may lose consistency when an unexpected event like a power failure occurs during recording. When recording a data stream, e.g. a video stream, an interruption would lead to a loss of stream data when previously known methods are used, because the file system is not updated. Further, the storage medium may become unusable. Dedicated file system data are put in regular intervals in user data fields of the data stream, providing the possibility to recover an interrupted stream recording. The method can also be used to recover data streams recorded on write-once discs, and it is independent from the used file system.

Claims

1. A method for recording an encoded data stream on a storage medium, said method comprising steps of:

determining a position in said encoded data stream where an additional data field according to an encoding format of said encoded data stream exists or may be inserted, said encoding format providing positions for insertion of additional data fields and said positions being independent from said storage medium;

if an additional data field exists at said determined position, modifying said existing additional data field, and otherwise inserting an additional data field into said encoded data stream at said determined position;

inserting file system information into one of said modified and inserted additional data field; and

recording said encoded data stream including said inserted file system information on said storage medium.

2. The method of claim 1, further comprising a step of determining a storage medium to be used for said recording after said inserting step.

3. The method of claim 1, further comprising a step of formatting said encoded data stream according to said storage medium after said inserting step.

4. The method of claim 1, wherein said file system information is collected in a non-volatile memory during said recording.

5. The method of claim 1, wherein said encoded data stream comprises one or more fragments defined by said encoding format, and said file system information inserted in said additional data field of a particular fragment of said encoded data stream comprises at least one of:

an identifier indicating a data type;

a file name;

a date and time of said recording;

an application type indicator;

a pointer to a beginning of a current fragment of said encoded data stream; and

a pointer to a next fragment of said encoded data stream, if said next fragment exists.

6. The method of claim 1, wherein said encoded data stream comprises one or more fragments defined by said encoding format, and said file system information inserted in said additional data field of a particular portion of said encoded data stream further comprises at least one of:

application information;

a version indication;

a path name and directory separators;

a pointer to a previous fragment of said encoded data stream, if said previous fragment exists;

an identifier for secondary information regarding which fragments belong together;

a fragment counting index; and

an indication for a first or last fragment, or both, of said encoded data stream.

7. The method of claim 1, wherein an amount of data recorded between successive additional data fields is constant, with maximum deviations of a contiguous data block according to said encoding format.

8. The method of claim 1, wherein marker bits are inserted in said file system information recorded in said additional data field to avoid forbidden code words.

9. The method of claim 1, wherein said storage medium is an optical storage medium.

10. The method of claim 1, wherein said encoded data stream complies with at least one of the MPEG-2, MPEG-4, WMV-9 and AVI standards, and said additional data fields are user_fields.

11. A method for reading encoded data from a storage medium, said method comprising steps of:

reading an area of said storage medium that is indicated by a file system as free, said storage medium storing said encoded data having an encoding format that provides positions for insertion of additional data fields and said positions being independent from said storage medium;

detecting that encoded data was read from said storage medium;

detecting a position of one of said additional data fields within said encoded data;

extracting data from said detected additional data field;

determining that said extracted data contains file system information; and

updating said file system according to said file system information.

12. The method of claim 11, wherein said encoded data comprises one or more fragments, and wherein said file system information contained in said detected additional data field of a particular fragment of said encoded data comprises at least one of:

an identifier indicating a data type;

a file name;

a date and time of recording;

an application type indicator;

a pointer to a beginning of a current fragment of said encoded data; and

a pointer to a next fragment of said encoded data, if said next fragment exists.

13. The method of claim 11, wherein said encoded data comprises one or more fragments, and wherein said file system information contained in said detected additional data field of a particular portion of said encoded data comprises at least one of:

additional application information;

an indication of a descriptor version;

a path name and directory separators;

a pointer to a previous fragment of said encoded data, if said previous fragment exists;

an identifier for secondary information regarding which fragments belong together;

a fragment counting index; and

an indication for a first or last fragment, or both, of said encoded data.

14. The method of claim 11, wherein an amount of said encoded data stored between successive additional data fields is constant, with maximum deviations of a contiguous data block according to said encoding format.

15. The method of claim 11, wherein marker bits are inserted in said file system information to avoid forbidden code words.

16. The method of claim 11, wherein said encoded data complies with at least one of the MPEG-2, MPEG-4, WMV-9 and AVI standards, and said additional data fields are user_fields.

17. An apparatus for recording an encoded data stream on a storage medium, said apparatus comprising:

means for determining a position in said encoded data stream where an additional data field according to an encoding format of said encoded data stream exists or may be inserted, said encoding format providing positions for insertion of additional data fields and said positions being independent from said storage medium;

means for modifying an existing said additional data field if said existing additional data field exists at said determined position;

means for inserting an additional data field into said encoded data stream at said determined position;

means for inserting file system information into one of said modified and inserted additional data fields; and

means for recording said encoded data stream including said inserted file system information on said storage medium.

18. The apparatus of claim 17, further comprising means for determining a storage medium to be used for said recording after inserting said file system information.

19. The apparatus of claim 17, further comprising means for formatting said encoded data stream with said inserted file system information according to said storage medium.

20. The apparatus of claim 17, wherein said file system information is collected in a non-volatile memory during said recording.

21. The apparatus of claim 17, wherein said encoded data stream comprises one or more fragments defined by said encoding format, and said file system information inserted in said additional data field of a particular fragment of said encoded data stream comprises at least one of:

an identifier indicating a data type;

a file name;

a date and time of recording;

an application type indicator;

a pointer to a beginning of a current fragment of said encoded data stream; and

a pointer to a next fragment of said encoded data stream, if said next fragment exists.

22. The apparatus of claim 17, wherein said encoded data stream comprises one or more fragments defined by said encoding format, and said file system information inserted in said additional data field of a particular portion of said encoded data stream further comprises at least one of:

additional application information;

a version indication;

a path name and directory separators;

a pointer to a previous fragment of said encoded data stream, if said previous fragment exists;

an identifier for secondary information regarding which fragments belong together;

a fragment counting index; and

an indication for a first or last fragment, or both, of said encoded data stream.

23. The apparatus of claim 17, wherein an amount of data recorded between successive additional data fields is constant, with maximum deviations of a contiguous data block according to said encoding format.

24. The apparatus of claim 17, wherein marker bits are inserted in said file system information recorded in said additional data field to avoid forbidden code words.

25. The apparatus of claim 17, wherein said encoded data stream complies with at least one of the MPEG-2, MPEG-4, WMV-9 and AVI standards, and said additional data fields are user_fields.

26. An apparatus for reading encoded data from a storage medium, said apparatus comprising:

means for reading an area of said storage medium that is indicated by a file system as free, said storage medium storing said encoded data having an encoding format that provides positions for insertion of additional data fields and said positions being independent from said storage medium;

means for detecting that encoded data was read from said storage medium;

means for detecting a position of one of said additional data fields within said encoded data;

means for extracting data from said detected additional data field;

means for determining that said extracted data contains file system information; and

means for updating said file system according to said file system information.

27. The apparatus of claim 26, wherein said encoded data comprises one or more fragments, and wherein said file system information contained in said detected additional data field comprises at least one of:

an identifier indicating a data type;

a file name;

a date and time of recording;

an application type indicator;

a pointer to a beginning of a current fragment of said encoded data; and

a pointer to a next fragment of said encoded data, if said next fragment exists.

28. The apparatus of claim 26, wherein said encoded data comprises one or more fragments, and wherein said file system information contained in said detected additional data field comprises at least one of:

application information;

a version indication;

a path name and directory separators;

a pointer to a previous fragment of said encoded data, if said previous fragment exists;

an identifier for secondary information regarding which fragments belong together;

a fragment counting index; and

an indication for a first or last fragment, or both, of said encoded data.

29. The apparatus of claim 26, wherein an amount of data stored between successive additional data fields is constant, with maximum deviations of a contiguous data block according to said encoding format.

30. The apparatus of claim 26, wherein marker bits are inserted in said file system information to avoid forbidden code words.

31. The apparatus of claim 26, wherein said encoded data complies with at least one of the MPEG-2, MPEG-4, WMV-9 and AVI standards, and said additional data fields are user_fields.