Recording medium, method, and apparatus for reproducing text subtitle streams

• US 7,512,322 B2
• Filed: 03/03/2005
• Issued: 03/31/2009
• Est. Priority Date: 03/17/2004
• Status: Expired due to Fees

• Current Assignee: Intellectual Discovery Co., Ltd.
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Yoo, Jea Yong, Kim, Byung Jin, Seo, Kang Soo
• Primary Examiner(s): Tran; Thai
• Assistant Examiner(s): Hasan; Syed Y
• Application Number:
  US11/069,959
• Publication Number:
  US 20050207737A1
• Time in Patent Office: 1,489 Days
• Field of Search: 386/95, 386/125, 386/E9.013, 386/E5.1, 386/E9.037, 386/E11.021, 715/723
• US Class Current: 386/248
• CPC Class Codes: G11B 20/12 Formatting, e.g. arrangement of data block or words on the record carriers within interface between computers and data recorders G06F3/06
• CPC Class Codes: G11B 2220/2541 Blu-ray discs; Blue laser DVR discs
• CPC Class Codes: G11B 27/10 Indexing; Addressing; Timing or synchronising; Measuring tape travel

Abstract

A recording medium, method, and apparatus for reproducing text subtitle streams are disclosed. A microcomputer initially reads a set of PlayItems and a SubPlayItem included in a PlayList which is recorded on a recording medium, and it further reads synchronization information included in the SubPlayItem. Each PlayItem is configured to reproduce at least one main AV stream, and the SubPlayItem is configured to reproduce a text subtitle stream. The synchronization information indicates a presentation start time of the SubPlayItem on a global time axis of the PlayList. When the PlayList is randomly accessed at a random access time on the global time axis, the microcomputer calculates a corresponding access time on a time axis of the SubPlayItem. Then a text subtitle decoder decodes for presentation a dialog presentation segment with the closest dialog start time after the corresponding access time on the axis of the SubPlayItem.

Claims

1. A recording medium, comprising:

a PlayList containing one or more PlayItems and at least one SubPlayItem, each PlayItem being configured to reproduce at least one main AV stream, the SubPlayItem being configured to reproduce a text subtitle stream, the SubPlayItem containing synchronization information which indicates a presentation start time of the SubPlayItem on a global time axis of the PlayList, the at least one main AV stream and the text subtitle stream including one or more presentation segments configured such that if the PlayList is randomly accessed at a random access time on the global time axis of the PlayList, one of the presentation segments with a start time directly after a corresponding random access time on a time axis of the text subtitle stream is presented.

2. The recording medium of claim 1, wherein the corresponding random access time on the time axis of the SubPlayItem is calculated by subtracting the presentation start time indicated in the synchronization information from the random access time on the global time axis.

3. The recording medium of claim 1, wherein the SubPlayItem starts its presentation at the presentation start time within a playing time interval of a selected one of the PlayItems.

4. The recording medium of claim 3, wherein the synchronization information includes a first data field indicating a PlayItem identification value of the selected PlayItem, and a second data field indicating the presentation start time of the SubPlayItem on the global time axis.

5. The recording medium of claim 1, wherein the SubPlayItem starts its presentation when presentation of the selected PlayItem has reached to the presentation start time of the SubPlayItem.

6. The recording medium of claim 5, wherein the synchronization information includes a first data field indicating a PlayItem identification value of the selected PlayItem, and a second data field indicating the presentation start time of the SubPlayItem on the global time axis.

7. The recording medium of claim 1, wherein each of the presentation segments includes at least one region of dialog text.

8. The recording medium of claim 7, wherein each of the presentation segments specifies presentation start and end times of the at least one region of dialog text on the time axis of the SubPlayItem.

9. The recording medium of claim 1, wherein the SubPlayItem includes a data field specifying a name of a Clip information file which corresponds to the text subtitle stream.

10. A method for reproducing data recorded on a recording medium, the method comprising:

reading a PlayList recorded on the recording medium, the PlayList containing one or more PlayItems and at least one SubplayItem, each PlayItem being configured to reproduce at least one main AV stream, and the SubPlayItem being configured to reproduce a text subtitle stream and including synchronization information which indicates a presentation start time of the SubPlayItem on a global time axis of the PlayList; and

if the PlayList is randomly accessed at a random access time on the global time axis, presenting a presentation segment with a start time directly after a corresponding random access time on a time axis of the text subtitle stream.

11. The method of claim 10, wherein the corresponding random access time on the time axis of the SubPlayItem is calculated by subtracting the presentation start time indicated in the synchronization information from the random access time on the global time axis.

12. The method of claim 10, wherein the SubPlayItem starts its presentation at the presentation start time within a playing time interval of a selected one of the PlayItems.

13. The method of claim 12, wherein the synchronization information includes a first data field indicating a PlayItem identification value of the selected PlayItem, and a second data field indicating the presentation start time of the SubPlayItem on the global time axis.

14. An apparatus for reproducing data recorded on a recording medium, comprising:

a microcomputer configured to read a PlayList recorded on the recording medium, the PlayList containing one or more PlayItems and at least one SubPlayItem, each PlayItem being configured to reproduce at least one main AV stream, the SubPlayItem being configured to reproduce a text subtitle stream and including synchronization information which indicates a presentation start time of the SubPlayItem on a global time axis of the PlayList; and

a text subtitle decoder configured to decode the text subtitle stream, wherein if the PlayList is randomly accessed at a random access time on the global time axis, the microcomputer is configured to control the text subtitle decoder to decode a dialog presentation segment with a start time directly after a corresponding random access time on a time axis of the SubPlayItem.

15. The apparatus of claim 14, wherein the microcomputer is configured to calculate the corresponding random access time on the time axis of the SubPlayItem by subtracting the presentation start time of the SubPlayItem from the random access time on the global time axis.

16. The apparatus of claim 14, wherein the microcomputer is configured to control a presentation of the SubPlayItem to be started at the presentation start time within a playing time interval of a selected one of the set of PlayItems.

17. The apparatus of claim 16, wherein the microcomputer is configured to read the SubPlayItem including the synchronization information including a first data field indicating a PlayItem identification value of the selected PlayItem, and a second data field indicating the presentation start time of the SubPlayItem on the global time axis.

18. A method for reproducing data recorded on a recording medium, the method comprising:

reading a set of PlayItems and a SubPlayItem included in a PlayList recorded on the recording medium, each PlayItem being configured to reproduce at least one main AV stream, the SubPlayItem being configured to reproduce a text subtitle stream loaded to a buffer and including synchronization information indicating a presentation start time of the SubPlayItem on a global time axis of the PlayList;

if the PlayList is randomly accessed at a random access time on the global time axis, calculating its corresponding random access time on a time axis of the SubPlayItem;

selecting a data location from an entry point (EP) map, the selected data location corresponding to a presentation time stamp directly after the calculated random access time on the time axis of the SubPlayItem; and

presenting a presentation segment stored in the selected data location within the buffer.

19. The method of claim 18, wherein the corresponding random access time on the time axis of the SubPlayItem is calculated by subtracting the presentation start time indicated in the synchronization information from the random access time on the global time axis.

20. The method of claim 18, wherein the SubPlayItem starts its presentation at the presentation start time within a playing time interval of a selected one of the PlayItems.

21. The method of claim 20, wherein the synchronization information includes a first data field indicating a PlayItem identification value of the selected PlayItem, and a second data field indicating the presentation start time of the SubPlayItem on the global time axis.

22. A recording medium, comprising:

a text subtitle stream configured to be reproduced synchronously with a main data stream, the text subtitle stream including one or more presentation segments; and

a PlayList including at least one PlayItem managing reproduction of the main data stream and at least one SubPlayItem managing reproduction of the text subtitle stream,

one of the presentation segments with a presentation start time directly after a random access time, corresponding to a random access time at which the PlayList is randomly accessed, on a time axis of the text subtitle stream being configured to be presented if the PlayList is randomly accessed.

23. The recording medium of claim 22, wherein the SubPlayItem starts its presentation at the presentation start time within a playing time interval of a selected one of the PlayItems.

24. The recording medium of claim 22, wherein the SubPlayItem starts its presentation when presentation of the selected PlayItem has reached the presentation start time of the SubPlayItem.

25. The recording medium of claim 22, wherein each of the presentation segments specifies presentation start and end times of the at least one region of dialog text on the time axis of the SubPlayItem.

26. A method of reproducing data recorded on a recording medium, the method comprising:

reading a PlayList including at least one PlayItem managing reproduction of at least one main data stream and at least one SubPlayItem managing reproduction of at least one text subtitle stream, the text subtitle stream including one or more presentation segments and reproduced synchronously with the main data stream; and

if the PlayList is randomly accessed, searching a random access point from the text subtitle stream and presenting the random access point,

the random access point being one of the presentation segments with a presentation start time directly after a random access time at which the PlayList is randomly accessed.

27. The method of claim 26, wherein the SubPlayItem starts its presentation at the presentation start time within a playing time interval of a selected one of the PlayItems.

28. The method of claim 26, wherein the SubPlayItem starts its presentation when presentation of the selected PlayItem has reached the presentation start time of the SubPlayItem.

29. The method of claim 26, wherein each of the presentation segments specifies presentation start and end times of the at least one region of dialog text on the time axis of the SubPlayItem.

30. An apparatus for reproducing data recorded on a recording medium, comprising:

a controller configured to control a text subtitle stream including one or more presentation segments to be reproduced synchronously with a main data stream, the text subtitle stream and the main data stream managed by a PlayList including a PlayItem and a SubPlayItem, and if the PlayList is randomly accessed, the controller being configured to search a random access point from the text subtitle stream and control the random access point to be presented,

wherein the controller is configured to control one of the presentation segments with a presentation start time directly after a random access time at which the PlayList is randomly accessed to be presented as the random access point.

31. The apparatus of claim 30, wherein the controller is configured to control the SubPlayItem starting its presentation at the presentation start time within a playing time interval of a selected one of the PlayItems.

32. The apparatus of claim 30, wherein the controller is configured to control the SubPlayItem starting its presentation when presentation of the selected PlayItem has reached to the presentation start time of the SubPlayItem.

33. The apparatus of claim 30, wherein the controller is configured to control each of the presentation segments specifying presentation start and end times of the at least one region of dialog text on the time axis of the SubPlayItem.