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.
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. 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.