Text subtitle decoder and method for decoding text subtitle streams

• US 7,561,780 B2
• Filed: 12/17/2004
• Issued: 07/14/2009
• Est. Priority Date: 02/10/2004
• Status: Expired due to Fees

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Yoo, Jea Yong, Kim, Byung Jin, Seo, Kang Soo
• Primary Examiner(s): Harvey; David E
• Application Number:
  US11/013,379
• Publication Number:
  US 20050196147A1
• Time in Patent Office: 1,670 Days
• Field of Search: 386/105, 386/95, 386/96, 386/98, 348/556, 348/468, 348/564, 348/467, 348/461
• US Class Current: 386/244
• CPC Class Codes: G11B 2020/10759 content data
• CPC Class Codes: G11B 2220/2541 Blu-ray discs; Blue laser DVR discs
• CPC Class Codes: G11B 27/105 of operating discs
• CPC Class Codes: G11B 27/34 Indicating arrangements indicating means incorporated in magazine or cassette G11B23/046 and G11B23/0875; indicating measured values in general G01D
• CPC Class Codes: H04N 21/4884 for displaying subtitles
• CPC Class Codes: H04N 5/85 on discs or drums
• CPC Class Codes: H04N 9/8042 involving data reduction
• CPC Class Codes: H04N 9/8063 using time division multiplex of the PCM audio and PCM video signals
• CPC Class Codes: H04N 9/8205 involving the multiplexing of an additional signal and the colour video signal
• CPC Class Codes: H04N 9/8227 the additional signal being at least another television signal
• CPC Class Codes: H04N 9/8233 the additional signal being a character code signal
• CPC Class Codes: H04N 9/8244 involving the use of subcodes
• CPC Class Codes: H04N 9/8715 involving the mixing of the reproduced video signal with a non-recorded signal, e.g. a text signal

Abstract

A method and a text subtitle decoder for decoding a text subtitle stream recorded on a recording medium are disclosed. A subtitle loading buffer initially loads a text subtitle stream including a dialog style segment defining a group of region styles and a dialog presentation segment having dialog presentation information and dialog text data for a dialog having at least one region. A text subtitle processor parses the dialog presentation segment into composition information, rendering information, and the dialog text data for each region. Next, a text renderer renders the text strings into a bitmap object for each region according to the rendering information, and the rendered bitmap object is composed in a graphics plane.

Claims

1. A method for decoding a text subtitle stream recorded on a recording medium, the method comprising:

loading the text subtitle stream into a subtitle loading buffer, the text subtitle stream including a style segment defining region styles and one or more presentation segment, each presentation segment including presentation information and text data for at least one region;

parsing the text subtitle stream into composition information, rendering information, and the text data for each region;

storing the parsed composition and the rendering information in a first buffer, and further storing the parsed text data in a second buffer, the text data including one or more text strings for each region;

rendering the text strings stored in the second buffer into a bitmap object for each region according to the rendering information, and storing the rendered bitmap object into a third buffer; and

composing the stored bitmap object in a graphics plane for each region according to the composition information.

2. The method of claim 1, further comprising storing the style segment in the first buffer immediately after the text subtitle stream is loaded.

3. The method of claim 1, wherein the rendering information includes at least one of a region size, font color, background color, text flow, text alignment, line space, font name, font style, and font size for each region.

4. The method of claim 1, wherein the rendering information includes at least a portion of region style information specifying one of the region styles defined by the style segment.

5. The method of claim 1, wherein the text data further includes a region style identifier which identifies one of the region styles defined by the style segment.

6. The method of claim 1, further comprising loading font data into a font loading buffer before the presentation segment is parsed, the font data being used when rendering the text strings stored in the second buffer.

7. The method of claim 1, wherein the composition information includes at least one of presentation time information, palette update information, and a region position for each region.

8. The method of claim 1, wherein the composition information includes the presentation information included in the presentation segment.

9. The method of claim 1, wherein the composition information includes at least a portion of region style information specifying one of the region styles defined by the style segment.

10. A method for decoding a text subtitle stream recorded on a recording medium, the method comprising:

preloading the text subtitle stream into a subtitle preloading buffer at once, the text subtitle stream including a style segment defining region styles and a presentation segment including presentation information and text data for at least one region, the text data including a region style identifier and one or more text strings for each region;

preloading related font data into a font preloading buffer at once;

storing the style segment in a composition buffer after the text subtitle stream is preloaded, the style segment including rendering information and composition information;

parsing the presentation segment into the composition information and the text data for each region;

storing the parsed composition information in the composition buffer for each region;

storing the parsed text data in a dialog buffer for each region;

rendering the text strings into a bitmap object for each region based on the rendering information and the preloaded font data;

storing the rendered bitmap object into a bitmap object buffer for each region; and

composing the stored bitmap object within a graphics plane for each region according to the composition information.

11. The method of claim 10, further comprising storing the style segment in the composition buffer immediately after the text subtitle stream is loaded.

12. The method of claim 10, wherein the rendering information includes at least one of a region size, font color, background color, text flow, text alignment, line space, font name, font style, and font size for each region.

13. The method of claim 10, wherein the rendering information includes at least a portion of region style information specifying one of the region styles defined by the style segment.

14. The method of claim 10, further comprising loading font data into a font loading buffer before the presentation segment is parsed, the font data being used when rendering the text strings stored in the dialog buffer.

15. The method of claim 10, wherein the composition information includes at least one of presentation time information, palette update information, and a region position for each region.

16. The method of claim 10, wherein the composition information includes the presentation information included in the presentation segment.

17. The method of claim 10, wherein the composition information includes at least a portion of region style information specifying one of the region styles defined by the style segment.

18. A text subtitle decoder for decoding a text subtitle stream recorded on a recording medium, the text subtitle decoder comprising:

a text subtitle processor configured to parse the text subtitle stream into composition information, rendering information, and text data for each region;

a composition buffer configured to store the composition arid the rendering information parsed from the text subtitle processor;

a dialog buffer configured to store the parsed text data, the text data including one or more text strings for each region;

a text renderer configured to render the text strings stored in the dialog buffer into a bitmap object for each region according to the rendering information;

a bitmap object buffer configured to store the rendered bitmap object; and

a presentation controller configured to compose the bitmap object stored in the bitmap object buffer according to the composition information.

19. The text subtitle decoder of claim 18, wherein the composition buffer is configure to store the style segment immediately after the text subtitle stream is loaded.

20. The text subtitle decoder of claim 18, wherein the text subtitle processor is configured to parse the text subtitle stream into rendering information including at least one of a region size, font color, background color, text flow, text alignment, line space, font name, font style, and font size for each region.

21. The text subtitle decoder of claim 18, wherein the text subtitle processor is configured to parse the text subtitle stream into rendering information including at least a portion of region style information specifying one of the region styles defined by the style segment.

22. The text subtitle decoder of claim 18, wherein the text subtitle processor is configured to parse the text subtitle stream into text data further including a region style identifier which identifies one of the region styles defined by the style segment.

23. The text subtitle decoder of claim 18, further comprising a font loading buffer configured to load font data before the presentation segment is parsed, wherein the text renderer uses the font data when rendering the text strings stored in the buffer.

24. The text subtitle decoder of claim 18, wherein the text subtitle processor is configured to parse the text subtitle stream into the composition information including at least one of presentation time information, palette update information, and a region position for each region.

25. The text subtitle decoder of claim 18, wherein the text subtitle processor is configured to parse the text subtitle stream into the composition information including the presentation information included in the presentation segment.

26. The text subtitle decoder of claim 18, wherein the text subtitle processor is configured to parse the text subtitle stream into the composition information including at least a portion of region style information specifying one of the region styles defined by the style segment.

27. The text subtitle decoder of claim 18, wherein the presentation controller is configured to control the dialog buffer, the text render and the bitmap object buffer.

28. The text subtitle decoder of claim 18, wherein the presentation controller is configured to provide the rendering information and the composition information.

29. A text subtitle decoder for decoding a text subtitle stream recorded on a recording medium, the text subtitle decoder comprising:

a subtitle preloading buffer configured to preload the text subtitle stream at once, the text subtitle stream including a style segment defining region styles and a presentation segment including presentation information and text data for at least one region, the text data including a region style identifier and one or more text strings for each region;

a font preloading buffer configured to preload related font data at once;

a composition buffer configured to store the style segment after the text subtitle stream is preloaded, the style segment including rendering information and composition information;

a text subtitle processor configured to parse the presentation information into the composition information and the text data for each region, the parsed composition information being stored in the composition buffer for each region;

a buffer configured to store the parsed text data for each region;

a text renderer configured to render the text strings into a bitmap object for each region based on the rendering information and the preloaded font data;

a bitmap object buffer configured to store the rendered bitmap object for each region;

a graphics plane in which the bitmap object stored in the bitmap object buffer for each region is composed according to the composition information; and

a presentation controller configured to provide the rendering information and the composition information to the text renderer and the graphics plane, respectively.

30. The text subtitle decoder of claim 29, wherein the composition buffer is configured to store the style segment immediately after the text subtitle stream is loaded.

31. The text subtitle decoder of claim 29, wherein the text subtitle processor is configured to parse the text subtitle stream into the rendering information including at least one of a region size, font color, background color, text flow, text alignment, line space, font name, font style, and font size for each region.

32. The text subtitle decoder of claim 29, wherein the text subtitle processor is configured to parse the text subtitle stream into the rendering information including at least a portion of region style information specifying one of the region styles defined by the style segment.

33. The text subtitle decoder of claim 29, configured to further comprise a font loading buffer configured to load font data before the presentation segment is parsed, wherein the text renderer uses the font data when rendering the text strings stored in the buffer.

34. The text subtitle decoder of claim 29, wherein the text subtitle processor is configured to parse the text subtitle stream into the composition information including at least one of presentation time information, palette update information, and a region position for each region.

35. The text subtitle decoder of claim 29, wherein the text subtitle processor is configured to parse the text subtitle stream into the composition information including the presentation information included in the presentation segment.

36. The text subtitle decoder of claim 29, wherein the text subtitle processor is configured to parse the text subtitle stream into the composition information including at least a portion of region style information specifying one of the region styles defined by the style segment.

37. An optical disc player for reproducing text subtitle streams recorded on an optical disc, the optical disc player comprising:

an audio decoder configured to decode audio streams recorded on the optical disc into audio data;

a video decoder configured to decode video streams recorded on the optical disc into video image data;

a text subtitle decoder configured to decode a text subtitle stream recorded on the optical disc into text subtitle image data; and

an image superimposition unit configured to superimpose the decoded text subtitle image data with the decoded video image data, wherein the text subtitle decoder comprises;

a text subtitle processor configured to parse the text subtitle stream into composition information, rendering information, and text data for at least one region, the text data including one or more text strings for each region;

a text renderer configured to render the text strings into graphic data for each region according to the rendering information; and

a presentation controller configured to compose the rendered graphic data according to the composition information.

38. The optical disc player of claim 37, wherein the text subtitle processor is configured to parse the text subtitle stream into the rendering information including at least one of a region size, font color, background color, text flow, text alignment, line space, font name, font style, and font size for each region.

39. The optical disc player of claim 37, wherein the text subtitle processor is configured to parse the text subtitle stream into the rendering information including at least a portion of region style information specifying one of the region styles defined by the style segment.

40. The optical disc player of claim 37, wherein the text subtitle processor is configured to parse the text subtitle stream into the text data further including a region style identifier which identifies one of the region styles defined by the style segment.

41. The optical disc player of claim 37, further comprising a font loading buffer configured to load font data before the presentation segment is parsed, wherein the text renderer uses the font data when rendering the text strings stored in the buffer.

42. The optical disc player of claim 37, wherein the text subtitle processor is configured to parse the text subtitle stream into the composition information including at least one of presentation time information, palette update information, and a region position for each region.

43. The optical disc player of claim 37, wherein the text subtitle processor is configured to parse the text subtitle stream into the composition information including the presentation information included in the presentation segment.

44. The optical disc player of claim 37, wherein the text subtitle processor is configured to parse the text subtitle stream into the composition information including at least a portion of region style information specifying one of the region styles defined by the style segment.

45. The optical disc player of claim 37, wherein the optical disc player is configured to further comprise a subtitle loading buffer loading the text subtitle stream, the text subtitle stream including a style segment defining region styles and a presentation segment including presentation information and text data having at least one region.

46. The optical disc player of claim 37, wherein the presentation controller is configured to control the text render.

47. The optical disc player of claim 37, wherein the presentation controller is configured to provide the rendering information and the composition information.

48. A method for decoding a text subtitle stream downloaded from an external source, the method comprising:

loading the text subtitle stream into a subtitle loading buffer, the text subtitle stream including a style segment defining region styles and one or more presentation segments, each presentation segment including presentation information and text data for at least one region;

parsing the text subtitle stream into composition information, rendering information, and the text data for each region;

storing the parsed composition and rendering information in a first buffer, and further storing the text data in a second buffer, the text data including one or more text strings for each region;

rendering the text strings stored in the second buffer into a bitmap object for each region according to the rendering information, and storing the rendered bitmap object into a third buffer; and

composing the stored bitmap object in a graphics plane for each region according to the composition information.

49. The method of claim 48, further comprising storing the style segment in the first buffer immediately after the text subtitle stream is loaded.

50. The method of claim 48, wherein the rendering information includes at least one of a region size, font color, background color, text flow, text alignment, line space, font name, font style, and font size for each region.

51. The method of claim 48, wherein the rendering information includes at least a portion of region style information specifying one of the region styles defined by the style segment.

52. The method of claim 48, wherein the text data further includes a region style identifier which identifies one of the region styles defined by the style segment.

53. The method of claim 48, further comprising loading font data into a font loading buffer before the presentation segment is parsed, the font data being used when rendering the text strings stored in the second buffer.

54. The method of claim 48, wherein the composition information includes at least one of presentation time information, palette update information, and a region position for each region.

55. The method of claim 48, wherein the composition information includes the presentation information included in the presentation segment.

56. The method of claim 48, wherein the composition information includes at least a portion of region style information specifying one of the region styles defined by the style segment.

57. A method for decoding a text subtitle stream downloaded from an external source, the method comprising:

preloading the text subtitle stream into a subtitle preloading buffer at once, the text subtitle stream including a style segment defining region styles and a presentation segment including presentation information and text data for at least one region, the text data including a region style identifier and one or more text strings for each region;

preloading related font data into a font preloading buffer at once;

storing the style segment in a composition buffer after the text subtitle stream is preloaded, the style segment including rendering information and composition information;

parsing the presentation segment into the composition information and the text data for each region;

storing the parsed composition information in the composition buffer for each region;

storing the parsed text data in a dialog buffer for each region;

rendering the text strings into a bitmap object for each region based on the rendering information and the preloaded font data;

storing the rendered bitmap object into a bitmap object buffer for each region; and

composing the stored bitmap object within a graphics plane for each region according to the composition information.

58. The method of claim 57, further comprising storing the style segment in the composition buffer immediately after the text subtitle stream is loaded.

59. The method of claim 57, wherein the rendering information includes at least one of a region size, font color, background color, text flow, text alignment, line space, font name, font style, and font size for each region.

60. The method of claim 57, wherein the rendering information includes at least a portion of region style information specifying one of the region styles defined by the style segment.

61. The method of claim 57, wherein the text data further includes a region style identifier which identifies one of the region styles defined by the style segment.

62. The method of claim 57, further comprising loading font data into a font loading buffer before the presentation segment is parsed, the font data being used when rendering the text strings stored in the dialog buffer.

63. The method of claim 57, wherein the composition information includes at least one of presentation time information, palette update information, and a region position for each region.

64. The method of claim 57, wherein the composition information includes the presentation information included in the presentation segment.

65. The method of claim 57, wherein the composition information includes at least a portion of region style information specifying one of the region styles defined by the style segment.

66. A text subtitle decoder for decoding a text subtitle stream downloaded from the external source, the text subtitle decoder comprising:

a subtitle preloading buffer configured to preload the text subtitle stream at once, the text subtitle stream including a style segment defining region styles and a presentation segment including presentation information and text data for at least one region, the text data including a region style identifier and one or more text strings for each region;

a font preloading buffer configured to preload related font data at once;

a composition buffer configured to store the style segment after the text subtitle stream is preloaded, the style segment including rendering information and composition information;

a text subtitle processor configured to parse the presentation information into the composition information and the text data for each region, the parsed composition information being stored in the composition buffer for each region;

a buffer configured to store the parsed text data for each region;

a text renderer configured to render the text strings into a bitmap object for each region based on the rendering information and the preloaded font data;

a bitmap object buffer configured to store the rendered bitmap object for each region;

a graphics plane in which the bitmap object stored in the bitmap object buffer for each region is composed according to the composition information; and

a presentation controller configured to provide the rendering information and the composition information to the text renderer and the graphics plane, respectively.

67. The text subtitle decoder of claim 66, wherein the composition buffer is configured to store the style segment immediately after the text subtitle stream is loaded.

68. The text subtitle decoder of claim 66, wherein the text subtitle processor is configured to parse the text subtitle stream into the rendering information including at least one of a region size, font color, background color, text flow, text alignment, line space, font name, font style, and font size for each region.

69. The text subtitle decoder of claim 66, wherein the text subtitle processor is configured to parse the text subtitle stream into the rendering information including at least a portion of region style information specifying one of the region styles defined by the style segment.

70. The text subtitle decoder of claim 66, further comprising a font loading buffer configured to load font data before the presentation segment is parsed, wherein the text renderer uses the font data when rendering the text strings stored in the buffer.

71. The text subtitle decoder of claim 66, wherein the text subtitle processor is configured to parse the text subtitle stream into the composition information including at least one of presentation time information, palette update information, and a region position for each region.

72. The text subtitle decoder of claim 66, wherein the text subtitle processor is configured to parse the text subtitle stream into the composition information including the presentation information included in the presentation segment.

73. The text subtitle decoder of claim 66, wherein the text subtitle processor is configured to parse the text subtitle stream into the composition information including at least a portion of region style information specifying one of the region styles defined by the style segment.

74. An optical disc player for reproducing text subtitle streams downloaded from an external source, the optical disc player comprising:

an audio decoder configured to decode audio streams recorded on the optical disc into audio data;

a video decoder configured to decode video streams recorded on the optical disc into video image data;

a text subtitle decoder configured to decode a text subtitle stream recorded on the optical disc into text subtitle image data; and

an image superimposition unit configured to superimpose the decoded text subtitle image data with the decoded video image data, wherein the text subtitle decoder comprises;

a text subtitle processor configured to parse the text subtitle stream into composition information, rendering information, and text data for at least one region, the text data including one or more text strings for each region;

a text renderer configured to render the text strings into graphic data for each region according to the rendering information; and

a presentation controller configured to compose the rendered graphic data according to the composition information.

75. The optical disc player of claim 74, wherein the text subtitle processor is configured to parse the text subtitle stream into the rendering information including at least one of a region size, font color, background color, text flow, text alignment, line space, font name, font style, and font size for each region.

76. The optical disc player of claim 74, wherein the text subtitle processor is configured to parse the text subtitle stream into the rendering information including at least a portion of region style information specifying one style defined by a style segment.

77. The optical disc player of claim 74, wherein the text subtitle processor is configured to parse the text subtitle stream into the text data further including a region style identifier which identifies one region style defined by a style segment.

78. The optical disc player of claim 74, further comprising a font loading buffer configured to load font data before the presentation segment is parsed, wherein the text renderer uses the font data when rendering the text strings stored in the buffer.

79. The optical disc player of claim 74, wherein the text subtitle processor is configured to parse the text subtitle stream into the composition information including at least one of presentation time information, palette update information, and a region position for each region.

80. The optical disc player of claim 74, wherein the text subtitle processor is configured to parse the text subtitle stream into the composition information including the presentation information included in the presentation segment.

81. The optical disc player of claim 74, wherein the text subtitle processor is configured to parse the text subtitle stream into the composition information including at least a portion of region style information specifying one region style defined by a style segment.

82. The optical disc player of claim 74, wherein the optical disc player is configured to further comprise a subtitle loading buffer loading the text subtitle stream, the text subtitle stream including a style segment defining region styles and a presentation segment including presentation information and text data having at least one region.

83. The optical disc player of claim 74, wherein the presentation controller is configured to control the text render.

84. The optical disc player of claim 74, wherein the presentation controller is configured to provide the rendering information and the composition information.