Method and apparatus for recording data and recovering recorded data

• US 20050091280A1
• Filed: 10/13/2004
• Published: 04/28/2005
• Est. Priority Date: 10/23/2003
• Status: Active Grant

• Current Assignee: Thomson Licensing (Vantiva SA)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Winter, Marco
• Granted Patent: US 7,155,448 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 a data stream on a storage medium, the data stream providing positions for insertion of additional, user definable data fields, and the data stream consisting of one or more fragments, wherein

one or more additional, user definable data fields are inserted into each fragment of the data stream;

and

file system information is inserted into at least one of said additional, user definable data fields.

2. Method according to claim 1, wherein file system information is collected in a non-volatile memory during the recording process.

3. Method according to claim 1, wherein the file system information contained in the additional, user definable data fields of a particular fragment of the data stream comprises at least

an identifier indicating the type of additional data;

the file name;

date and time of recording;

application type indicator;

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

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

4. Method according to claim 1, wherein the file system information contained in the additional, user definable data fields of a particular partition of the first data further comprises one or more of

additional application information;

an indication of the descriptor version;

path name and directory separators;

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

identifier to get secondary information regarding which fragments belong together;

a fragment counting index; and

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

5. Method according to claim 1, wherein the amount of stored data between successive additional, user definable data fields is constant, with maximum deviations of a contiguous data block.

6. Method according to claim 1, wherein additional marker bits are inserted in the file system information stored in the additional, user definable data field in order to avoid forbidden code words.

7. Method according to claim 1, wherein the storage medium is an optical storage medium.

8. Method according to claim 1, wherein the data stream complies with the MPEG standard, and the additional, user definable data fields are user_fields.

9. A method for reading a data stream from a storage medium, the storage medium being structured into partitions, the data stream containing additional, user definable data fields, and the data stream consisting of one or more fragments, wherein

one or more partitions of the storage medium are read that are indicated by the file system as free;

additional, user definable data fields that contain a recovery descriptor are detected, wherein a recovery descriptor is a data set containing an identifier and file system data;

first file system data from a first detected file recovery descriptor and second file system data from a second detected file recovery descriptor are compared; and

based on the result of said comparison, the file system of the storage medium may be updated to indicate the read partition as not being free, or the data stream may be retrieved.

10. Method according to claim 9, wherein the file system information contained in the additional, user definable data fields of a particular fragment of the data stream comprises at least

an identifier indicating the type of additional, user definable data;

the file name;

date and time of recording;

application type indicator;

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

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

11. Method according to claim 9, wherein the file system information contained in the additional, user definable data fields of a particular partition of the first data further comprises one or more of

additional application information;

an indication of the descriptor version;

path name and directory separators;

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

identifier to get secondary information regarding which fragments belong together;

a fragment counting index; and

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

12. Method according to claim 9, wherein the amount of stored data between successive additional, user definable data fields is constant, with maximum deviations of a contiguous data block.

13. Method according to claim 9, wherein additional marker bits are inserted in the file system information stored in the additional, user definable data field in order to avoid forbidden code words.

14. Method according to claim 9, wherein the data stream complies with the MPEG standard, and the additional, user definable data fields are user_fields.

15. An apparatus for recording a data stream on a storage medium, the data stream containing additional, user definable data fields, and the data stream comprising one or more fragments, wherein the apparatus has

means for inserting at least one additional, user definable data field into each fragment of the data stream;

and

means for inserting file system information in the additional, user definable data fields.

16. Apparatus according to claim 15, wherein file system information is collected in a non-volatile memory during the recording process.

17. Apparatus according to claim 15, wherein the file system information contained in the additional, user definable data fields of a particular fragment of the data stream comprises at least

an identifier indicating the type of additional data;

the file name;

date and time of recording;

application type indicator;

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

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

18. Apparatus according to claim 15, wherein the file system information contained in the additional, user definable data fields of a particular partition of the first data further comprises one or more of

additional application information;

an indication of the descriptor version;

path name and directory separators;

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

identifier to get secondary information regarding which fragments belong together;

a fragment counting index; and

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

19. Apparatus according to claim 15, wherein the amount of stored data between successive additional, user definable data fields is constant, with maximum deviations of a contiguous data block.

20. Apparatus according to claim 15, wherein additional marker bits are inserted in the file system information stored in the additional, user definable data field in order to avoid forbidden code words.

21. Apparatus according to claim 15, wherein the data stream complies with the MPEG standard, and the additional, user definable data fields are user_fields.

22. An apparatus for reading a data stream from a storage medium, the data stream containing additional, user definable data fields, and the data stream comprising one or more fragments, wherein the apparatus has

means for reading one or more data partitions of the storage medium that are indicated by the file system as free;

means for detecting within said partitions additional, user definable data fields that contain a recovery descriptor, wherein a recovery descriptor is a data set containing an identifier and file system data;

means for comparing first file system data from a first detected file recovery descriptor and second file system data from a second detected file recovery descriptor; and

means for retrieving the data stream or updating the file system of the storage medium, based on the result of said comparison.

23. Apparatus according to claim 22, wherein the file system information contained in the additional, user definable data fields of a particular fragment of the data stream comprises at least

an identifier indicating the type of additional, user definable data;

the file name;

date and time of recording;

application type indicator;

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

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

24. Apparatus according to claim 22, wherein the file system information contained in the additional, user definable data fields of a particular partition of the first data further comprises one or more of

additional application information;

an indication of the descriptor version;

path name and directory separators;

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

identifier to get secondary information regarding which fragments belong together;

a fragment counting index; and

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

25. Apparatus according to claim 22, wherein the amount of stored data between successive additional, user definable data fields is constant, with maximum deviations of a contiguous data block.

26. Apparatus according to claim 22, wherein additional marker bits are inserted in the file system information stored in the additional, user definable data field in order to avoid forbidden code words.

27. Apparatus according to claim 22, wherein the data stream complies with the MPEG standard, and the additional, user definable data fields are user_fields.