HK1098870B - Apparatus for processing text-based subtitle - Google Patents

Description

Apparatus for processing text-based subtitles

Technical Field

The present invention relates to a subtitle, and more particularly, to a text-based subtitle and an apparatus and method for processing the subtitle.

Background

The conventional subtitles are generated in the form of bitmap images and included in an MPEG stream. Since the subtitle has a bitmap image format, it is inconvenient to generate the subtitle, and a user has to passively accept various attributes of the subtitle defined and provided by a subtitle producer. That is, the user cannot select a style of the subtitle, such as a text color, a text size, or an output direction of the text. Therefore, the user views a monotone style subtitle.

Generally, subtitles of a movie use some typical formats without frequent changes in output style, such as changes in text color, text position, text size, and text shape. In order to render (render) text, each character requires different information about its color, size, position and shape. If the rendering information is added to each sentence of the subtitle, there is provided an advantage that a different style can be specified for each sentence. However, in a movie script using only some typical styles, the disadvantage of an increase in the amount of data required for subtitles and the amount of data to be processed is more than the advantage of being able to provide various styles.

DISCLOSURE OF THE INVENTION

Technical solution

The present invention provides an information storage medium storing text-based subtitles.

The present invention also provides a subtitle processing apparatus and method, by which subtitles can be output in various ways.

Advantageous effects

According to the present invention, an output style of a subtitle is defined by a stylegroup (stylegroup) and a style (style) included in the stylegroup, and each statement of a movie script specifies a predefined stylegroup or style, so that the amount of data for the subtitle and the amount of data to be processed when the subtitle is output can be greatly reduced.

Further, by designating the output format of the subtitle as a stylegroup or a style, the output format cannot be completely changed by the user, and the intention of the producer can be effectively reflected. In addition, the style or style set may be selected by the user so that the user may select a desired output style.

Drawings

Fig. 1 is a diagram illustrating a structure of a text-based subtitle file according to an embodiment of the present invention.

Fig. 2 is a diagram illustrating information required to render script text and text output rendered according to the information, according to an embodiment of the present invention.

Fig. 3A illustrates a markup document defining a stylegroup according to an embodiment of the present invention.

Fig. 3B illustrates another markup document defining a stylegroup according to an embodiment of the present invention.

Fig. 4A illustrates a markup document in which basic style information is defined in a stylegroup according to an embodiment of the present invention.

Fig. 4B illustrates another markup document in which basic style information is defined in a stylegroup according to an embodiment of the present invention.

Fig. 5A illustrates an example of a markup language tag for displaying subtitles according to an embodiment of the present invention.

Fig. 5B illustrates another example of a markup language tag for displaying subtitles according to an embodiment of the present invention.

Fig. 6A illustrates a relationship between dialog information and presentation information according to an embodiment of the present invention.

Fig. 6B illustrates another relationship between dialog information and presentation information according to an embodiment of the present invention.

Fig. 7A is a diagram illustrating how a style is changed by a style change command according to an embodiment of the present invention.

Fig. 7B is a diagram illustrating how a stylegroup is changed by a stylegroup change command according to an embodiment of the present invention.

Fig. 8A is a diagram illustrating how style information required to render each script item is selected for presentation information formed as shown in fig. 4A.

Fig. 8B and 8C are diagrams illustrating how style information required to render each script item is selected for presentation information formed as shown in fig. 4B.

Fig. 9 is a block diagram illustrating a text-based subtitle processing apparatus according to an embodiment of the present invention.

Fig. 10 is a flowchart illustrating a text-based subtitle processing method according to an embodiment of the present invention.

Best mode

According to an aspect of the present invention, there is provided an information storage medium storing multimedia data, the multimedia data including: audio/visual (AV) data; and subtitle data including script text data output in synchronization with the AV data and output style information of a text format for specifying an output type of the script text.

The subtitle data may be recorded in the form of a markup document or in the form of binary data.

According to another aspect of the present invention, there is provided an information storage medium storing text-based subtitle information, the information including: dialog information including script text information of a subtitle and information specifying an output type of the script text; presentation information including style information for rendering and displaying script text.

The dialog information and/or the presentation information may be recorded in the form of a markup document or in the form of binary data.

The dialog information may include: script text data; a start time indicating when the script file begins to be displayed; an end time indicating when display of the script text ends; and style data specifying a display style to be used when the script text is rendered.

The presentation information may include: at least one stylegroup recorded with presentation style information, the stylegroup including at least one style in which information to be used for rendering and a presentation style of script text are recorded.

The stylegroup may include style information that is not changeable by a user, and the at least one style includes style information that is changeable by a user.

Style information included in a style selected by a user may be applied to style information included in a stylegroup, thereby changing an output type of script text.

The style information included in the selected style may replace the style information included in the stylegroup including the selected style, or may be added to the style information, or may be subtracted from the style information.

Script text included in the dialog information may specify one of the stylegroups, and a user may select one of the at least one style included in the specified stylegroup, and the script text may be displayed by using information recorded in the specified stylegroup and information recorded in the selected style.

The script text included in the dialog information may specify one of a plurality of styles included in the stylegroup, and the user may select one of the at least one stylegroup, and the script text may be displayed by using information recorded in the specified style and information recorded in the selected stylegroup.

According to another aspect of the present invention, there is provided a text subtitle processing apparatus including: a text subtitle parser for extracting presentation information and dialog information from text-based subtitle data; and a text layout/font renderer for rendering the extracted dialog information by referring to the presentation information and generating a script text image.

The apparatus may further include: a buffer for reading text-based subtitle data and font data from a disc and storing the data; and a presentation engine for reading the rendered script text image and the bitmap-type script text data read from the disc, and generating a graphic image by combining the rendered script text image and the bitmap-type script text data.

According to another aspect of the present invention, there is provided a text subtitle processing method including: reading and storing text-based subtitle data and font data; extracting presentation information and dialog information from the subtitle data; rendering script text and generating a text image using the extracted presentation information and dialog information; reading subtitle data in the form of bitmap images; combining the subtitle data with the rendered text image; and outputting the combined image.

According to another aspect of the present invention, there is provided a computer-readable recording medium having stored thereon a computer program of the method.

Detailed Description

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.

Referring to fig. 1, a text-based subtitle file 100 includes dialog information 110, presentation information 120, and metadata 130a and 130 b.

The dialog information 110 includes script text, an output start time of the text, an output end time, a stylegroup (stylegroup) or style information to be used to render the text, text change effect information such as fade-in/fade-out, and a format code for the text.

The format code includes a code representing text in bold, a code representing text in italics, an underlined code, a code indicating a line feed, and the like.

The presentation information 120 includes style information to be used for rendering script text, and is formed with a plurality of style sets. A stylegroup is a set of styles in which style information is recorded.

The style (style) includes information to be used for rendering script text and outputting it to a screen. Examples of such information are the name of the style, font, text color, background color, text size, text output region, start position of text output, output direction, alignment method, and the like.

The range of the property changeable by the user varies depending on which information is defined as a style and a stylegroup, and a method of specifying style information will be explained below.

The metadata 130a and 130b are additional information about the moving picture, including information required to perform additional functions other than outputting subtitles.

Fig. 2 is a diagram illustrating information required to render script text and a screen rendered and output according to the information.

The output region information (1, t, w, h)210 indicates a region in which text is to be output, and indicates that the region starts at the coordinates (1, t), has a width w, and has a height h. The output start position information (x, y)221 indicates a reference point when text is output on the screen, and indicates that the reference point should be located within the area (1, t, w, h). The text alignment information 222 specifies an alignment method of the text. The text may be left justified, center justified or right justified. When the text is left-justified, the text extends rightward from the output start position (x, y). When the text is in middle alignment, the text is centered on the output start position (x, y). When the text is right justified, the text extends to the left from the output start position (x, y). In fig. 2, an example of outputting text in a left-justified manner is shown.

The font size information 230 indicates the size of text to be output. Line height information 240 indicates the line spacing of the text. The background color information 250 defines the background color of the output region (1, t, w, h). Text color information 260 defines the color of text to be output. The font name 270 specifies the font to be used for text rendering.

The format code 280 and the character data 290 are included in the dialog information 110. Format code 280 may include code for line feed and bold, italic and underline processing of text. The character data 290 is script text information to be displayed as a subtitle. The output direction of text can be defined as (left- > right, up- > down) or (up- > down, right- > left). In FIG. 2, the output direction is (left- > right, up- > down). The above-described various information other than the format code 280 and the character data 290 is included in the presentation information 120.

There are various methods of representing information required for text rendering in text-based subtitles. By defining a structure in which pieces of information are recorded, a structure in a binary format may be formed, or a mark format corresponding to the information structure may be used. Unlike a markup document in which information is recorded as text, information stored in a binary format is represented by a string of binary data in units of predetermined bytes. That is, for example, a predetermined number of bytes of the header may be used for the name of the style, the next bytes for the font, and the next bytes for the text color. In this way, information required for rendering is recorded in a binary format. Next, the information structure will be explained as an example.

There are various methods of forming styles and stylegroups indicating style information to be used for rendering and displaying each script statement included in the dialog information 110.

In one method, each script statement included in the dialog information 110 specifies a stylegroup, and a user selects one of the styles included in the specified stylegroup. In another method, a stylegroup is selected by a user, and each script statement included in dialog information 110 specifies one of a plurality of styles included in the stylegroup. Accordingly, all information required for rendering a script statement is included in a style, and any piece of style information to be used for rendering an output script may be changed according to a user's selection. That is, if the user changes the output style of the script, all pieces of information may be changed according to style information provided by the producer.

Now, the above-described various situations will be explained in more detail with reference to fig. 3A to 6B. Fig. 3A illustrates a markup document defining a stylegroup according to an embodiment of the present invention. The presentation information is recorded in the form of a styleset (styleset). The stylegroups include a plurality of stylegroups defined by a producer. Each stylegroup has a name attribute indicating a name of each group, and each group is identified by the stylegroup name indicated by the name attribute. A stylegroup is a set of attribute information for outputting a subtitle according to a style desired by a producer.

For example, if a producer desires that a subtitle of a title of a movie is output in the center of a screen in a large font, that the subtitle is output in a font size that does not affect the viewing of the movie at the bottom of the screen, and that the subtitles of actors at the end of the movie are aligned in the middle across the entire screen, the producer divides a style set into three style sets: "Title", "Script", and "Casting", each style group is defined, and one of the three style groups defined in the presentation information is assigned to each Script recorded in the dialog information of the subtitle file. These stylegroups cannot be changed by a user watching a movie.

Each style group includes styles in which information required to render text is recorded. The style includes a name for identifying the style and various information items required for rendering text. In the stylegroups, a plurality of styles may be defined, and it is preferable that the number of styles and the style names defined in each stylegroup be the same for all stylegroups. Since the first style among a plurality of styles defined in a stylegroup may be selected as a default or a default style may be selected by a producer, the style selected as the default is applied to text rendering when an initial subtitle is output on a screen, and if the style is arbitrarily changed by a user when a movie is reproduced, then a style specified by the user is applied to text rendering thereafter.

Fig. 3B is a markup document defining a stylegroup according to an embodiment of the present invention. Referring to fig. 3B, Title, Script, and Casting are three categories of subtitles and are defined as styles. According to the output style of script text, a stylegroup including these three styles is classified into Small, Normal, and Large. In each script statement of dialog information, a style defined in presentation information is specified. In this case, since the first stylegroup may be selected as a default or a default stylegroup may be selected by a producer, a style indicated by each script statement of dialog information among styles included in the stylegroup selected as the default is applied to text rendering when an initial subtitle is output on a screen, and if a user changes the stylegroup when a movie is reproduced, a style included in a stylegroup designated by the user is then applied to text rendering.

When the presentation information is defined as shown in fig. 3A and 3B, if the user changes the style, all style information items are changed. However, depending on the situation, it may be more effective to change only a part of the style information, and for this reason, the presentation information may be defined as shown in fig. 4A and 4B.

Fig. 4A is a markup document in which basic style information is defined in a stylegroup according to an embodiment of the present invention. Unlike the presentation information shown in fig. 3A and 3B, in fig. 4A, a stylegroup includes information that does not change when a script output style is changed by a user. Further, the stylegroup includes one or more styles, which include style information that can be changed by a user's selection, and each style is identified by a name attribute.

Referring to fig. 4A, a style set includes three types of style groups identified by "Title", "Script", and "Casting", each including font (front), color (color), background (background), alignment (align), region (region), and line height (lineheight) information, which maintain a fixed value even when a user changes a style. Each stylegroup also includes three styles: "normal font", "small font", and "large font", which have size (size), position (position), and direction (direction) information whose values change when a user changes a style. The style may have a default attribute for indicating a default style selected by the producer, or the first style may be selected as the default.

In this case, font, color, background, alignment, region, and line height style information included in the stylegroup, and size, position, and direction style information included in a style selected by the user or in a default style are used to form a complete set of style information to be used for rendering script text.

Fig. 4B is another markup document in which basic style information is defined in a stylegroup according to an embodiment of the present invention. As in fig. 4A, the stylegroup with presentation information shown in fig. 4B includes all style information required to render script text. Further, the stylegroup includes one or more styles, which include style information that can be changed by a user's selection, and each style is identified by a name attribute.

Referring to fig. 4B, the stylegroup includes three types of stylegroups identified by "Title", "Script", and "Casting", each stylegroup including font (front), color (color), background (background), alignment (align), region (region), line height (lineheight), size (size), position (position), and direction (direction) information to be used for rendering a Script, and also includes two styles: "smallfount" and "large font", which include size, position, and direction information whose values change when a user changes a style.

When there is no change input by the user, only font, color, background, alignment, region, line height, size, position, and orientation information items included in the stylegroup are used in order to form a complete set of style information for rendering script text. If the user changes the style, size, position, and direction information included in the selected style is applied to the size, position, and direction information, and an output style of the script is changed.

At this time, the values included in the stylegroup may be replaced by the values included in the selected style, or the values included in the selected style may be added to the values included in the stylegroup. When the latter method is used, the values of the size, position, and direction attributes included in the stylegroup may be represented as positive or negative numbers, and the numbers may be added to or subtracted from the values included in the stylegroup.

Fig. 5A illustrates an example of a markup tag for displaying subtitles according to an embodiment of the present invention. The < text > tag serves as a unit for classifying a script to be output on a screen. The attribute information included in the < text > tag includes: "start" indicating the time when text output starts; "end" indicating the time when the output ended; "effect" indicating a changing effect to be applied to the text, such as fade in/out; and "stylegroup," indicating style information to be used for rendering text. Wherein, the "start" and "end" information are time information of the screen output. Further, a script to be output on the screen is recorded in a < text > tag.

Referring to FIG. 5A, the Script text "John!is rendered using a default style among a plurality of styles included in the stylegroup" Script "or style information designated by a user! And by applying a "fade-in" effect, the text is displayed and gradually becomes clear at the start time "00: 10: 00" until the end time "00: 10: 15".

Fig. 5B illustrates another example of a markup language tag for displaying subtitles according to an embodiment of the present invention. Referring to fig. 5B, a < text > tag specifies a style, rather than a stylegroup, to render script text. In this case, the Script text included in the < text > tag is rendered using a style "Script" among a plurality of styles included in the default stylegroup or a stylegroup specified by the user.

Fig. 6A illustrates a relationship between dialog information and presentation information according to the present invention. As described above with reference to fig. 5A, each < text > tag including dialog information has a stylegroup field indicating style information to be used for rendering text. The stylegroup field indicates one of a plurality of stylegroups stored in a stylegroup representing information, and a default style or a style specified by a user provides information required to render text, among styles included in a specified stylegroup.

Referring to fig. 6A, two < text > tags indicate stylegroups "Title" and "Script", respectively. Each of the two < text > tags corresponds to one of the styles included in the corresponding style group "Title" or "Script" recorded in the presentation information.

Fig. 6B illustrates another relationship between dialog information and presentation information according to an embodiment of the present invention. Each < text > tag indicates a style other than a stylegroup as text rendering information, and corresponding style information is recorded as one of a plurality of styles included in a plurality of stylegroups stored in presentation information. Referring to fig. 6B, two < text > tags including dialog information indicating styles "Title" and "Script", respectively, correspond to one of stylegroups "Small" and "Normal" recorded in presentation information.

Now, a user operation and an Application Program Interface (API) by which a user changes a style will be explained with reference to fig. 7A and 7B. Fig. 7A is a diagram showing how a style is changed by a style change command. Referring to fig. 7A, stylegroups "Title", "Script", and "Casting" are defined such that each stylegroup includes styles "Small", "Normal", and "Large". The stylegroup "Title" uses middle alignment and outputs blue text, the stylegroup "Script" uses left alignment from the bottom left side and outputs black text, and the stylegroup "Casting" uses right alignment from the top right side and outputs red text. The styles "Small", "Normal", and "Large" have style information indicating that they are output in Small-size text, Normal-size text, and Large-size text, respectively.

At time "00: 00: 10", the stylegroup "Title" is used as information for rendering text, and the default style "Small" included in the stylegroup "Title" is used as style information. When the user changes the text style to the style "Normal" during reproduction of the movie, the style "Normal" of the stylegroup "Title" is used as the style information. Further, when the style set is changed at time "00: 10: 20" as the movie progresses, the style "Normal" of the style set "Script" is used, and when the style set is changed to "Casting" at time "01: 10: 25", the style "Normal" selected by the user continues to be applied using the style set "Casting".

Fig. 7B is a diagram illustrating how a stylegroup is changed by a stylegroup change command. Referring to fig. 7B, stylegroups "Small", "Normal", and "Large" are defined, and each stylegroup includes styles "Title", "Script", and "Casting". At time "00: 00: 10", style information of the style "Title" included in the default style group "Small" is used as information for rendering text. When the user changes the stylegroup from "Small" to "Normal" during reproduction of the movie, the style "Title" of the stylegroup "Normal" is used as the style information. Further, when the style is changed from "Title" to "Script" at the time of changing to "00: 10: 20" as the movie proceeds, the style "Script" of the style set "Normal" is used, and when the style is changed to "Casting" at the time of "01: 10: 25", the style "Casting" included in the style set "Normal" designated by the user is applied.

Fig. 8A is a diagram illustrating how style information required to render each script item is selected for presentation information formed as shown in fig. 4A. Each script of dialog information indicates one of one or more stylegroups included in a stylegroup. Further, one of one or more styles included in each stylegroup is selected, and if there is no user selection, the style "Normal" is selected as a default, and when there is a user selection, the corresponding style is selected.

Now, a process of forming style information to be used for rendering the script "Text 1" will be explained. Since the script "Text 1" indicates the stylegroup "Title", non-selectable information included in the stylegroup "Title" that cannot be selectively changed by the user is selected. If the user selects the style "Large", the option information included in the style is selected. Then, the non-selectable information of the stylegroup "Title" and the selectable information of the style "Large" of the stylegroup "Title" are combined to form a complete set of style information.

Now, a process of forming style information to be used for rendering the script "Text 2" will be explained. First, since the Script "Text 2" indicates the stylegroup "Script", non-selectable information included in the stylegroup "Script" that cannot be selectively changed by a user is selected. If the style "Large" is selected by the user, the optional information included in the style "Large" is selected. Then, the non-selectable information of the style set "Script" and the selectable information of the style "Large" of the style set "Script" are combined to form a complete set of style information.

Now, a process of forming style information required to render each script item in the presentation information formed as shown in fig. 4B will be explained with reference to fig. 8B and 8C. Fig. 8B and 8C are diagrams illustrating how style information required to render each script item is selected for presentation information formed as shown in fig. 4B.

Fig. 8B will be used to illustrate a process of forming a complete set of style information required to render script text when the style is not changed by the user. Each script of dialog information indicates one of one or more stylegroups included in a stylegroup. When the user does not change the style, all style information items (information for text rendering) required for script text included in the stylegroup indicated by the script are used to form a complete set of style information. When the user changes styles, one of one or more styles included in each stylegroup is selected, and information included in the user-selected style is applied to information included in the stylegroup for rendering text to form a complete set of style information.

Referring to fig. 8B, since the script "Text 1" indicates the stylegroup "Title", information for rendering Text included in the stylegroup "Title" is selected and used to form a complete set of style information to be used for rendering script Text.

Further, since the Script "Text 2" indicates the stylegroup "Script", information for rendering Text included in the stylegroup "Script" is selected and used to form a complete set of style information to be used for rendering Script Text.

Fig. 8C will be used to explain a process of forming a complete set of style information required to render script text when a user changes a style. Since the script "Text 1" indicates the stylegroup "Title", information for rendering Text included in the stylegroup "Title" is selected. If the style "Large" is selected by the user, the optional information included in the style "Large" is selected. The optional information of the style "Large" of the stylegroup "Title" is applied to the information of the stylegroup "Title" for rendering text to form a complete set of style information.

In forming style information to be used for rendering the Script "Text 2", since the Script "Text 2" indicates the stylegroup "Script", information for rendering Text included in the stylegroup "Script" is selected. If the style "Large" is selected by the user, the optional information included in the style "Large" is selected. Then, the selectable information of the style "Large" of the style set "Script" is applied to the information of the style set "Script" for rendering text to form a complete set of style information.

Fig. 9 is a block diagram of a text-based subtitle processing apparatus according to an embodiment of the present invention. The text-based subtitle processing apparatus includes a text subtitle processing unit 920 required to render text. The text subtitle processing unit 920 includes: a text subtitle parser 921 for extracting presentation information and dialog information from subtitles; and a text layout/font renderer 922 for generating an output image by rendering text according to the extracted representation information.

After text-based subtitle information and font information are read from the disc 900 and stored in the buffer 910, subtitles are transmitted to the text subtitle parser 921 of the subtitle processing unit 920, and presentation information and dialog information are extracted. The extracted information is sent to the text layout/font renderer 922 and the composition buffer 933 of the presentation engine 930. The text layout/font renderer 922 generates an image to be displayed on a display device by rendering text using the transmitted style information and font information, and transmits the image to an object buffer 934 included in the presentation engine 930.

Subtitles in the form of bitmap images are read from the disc 900, input to an encoded data buffer 931, processed by a graphic processing unit 932, and sent to a composition buffer 933 and an object buffer 934. The composition buffer 933 receives the object composition information transmitted by the text subtitle parser 921 and the bitmap subtitle data processed by the graphic processing unit 932, and transmits control information for screen output to the graphic control unit 935. The object buffer 934 combines the bitmap subtitle data processed by the graphics processing unit 932 and the rendered text subtitle objects received from the text layout/font renderer 922, generates a graphics plane 940, and outputs the graphics plane 940 to a display device by referring to a color lookup table (CLUT) 950.

Fig. 10 is a flowchart illustrating a method of processing text-based subtitles according to an embodiment of the present invention. Text-based subtitle data and font data are read from the disc and stored in a buffer in operation S1010. The subtitle data in the form of a bitmap image is sent to a presentation engine. In operation S1020, presentation information and dialog information are extracted from the stored subtitle data. The presentation information and the dialog information are as described above. In operation S1030, text is rendered and an image is generated by using the extracted presentation information and dialog information. In operation S1040, subtitle data in the form of a bitmap image transmitted to the presentation engine and the rendered and generated image are combined and output. The combination of bitmap data and rendered image is as described above with reference to fig. 9.

Described above is forming a style for rendering text having a text subtitle in the form of text and outputting the text on a screen, thereby displaying a script for a moving picture. In the present invention, a plurality of styles that can be selected by a user are provided by a producer, and when a script is output, the user selects one of the plurality of styles to change an output style of the script. Accordingly, the style set, and the style of the present invention may further include a field for recording information required for a script providing a moving picture. That is, the stylegroups described in the present invention include only stylegroups, but fields recording additional data (e.g., information indicating style information) may be added in addition to stylegroups, and stylegroups and styles described in the present invention may also have additional fields. In addition, the position of each field included in the stylegroup and the style may vary according to implementation of the text subtitle.

The present invention can also be embodied as computer readable codes on a computer readable recording medium. The computer readable recording medium may be any data storage device that can store data which can be thereafter read by a computer system. Examples of the computer readable recording medium include read-only memory (ROM), random-access memory (RAM), CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, and carrier waves (such as data transmission through the internet). The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Claims (1)

1. A text subtitle processing apparatus, comprising:

a text subtitle parser for extracting a style set and dialog information from subtitle data; and

a text layout/font renderer for rendering the extracted dialog information by referring to the style set and generating a script text image;

an object buffer receiving the generated script text image from the text layout/font renderer;

wherein the script text image received from the object buffer is output to a display device through a graphics plane,

the dialog information includes script text information of subtitle data,

the stylegroup comprises a plurality of stylegroups, each stylegroup comprising first style information for rendering and displaying script text information and second style information for rendering and displaying script text information,

the dialog information further includes an identifier corresponding to a stylegroup of the plurality of stylegroups,

rendering script text information using first style information contained in a stylegroup indicated by an identifier corresponding to the stylegroup,

when the user selects the second style information included in the indicated stylegroup to change the output style of the script text information, changed style information is formed by adding at least one of values regarding size, position, and direction included in the selected second style information to a corresponding value included in the first style information of the indicated stylegroup, and the script text information is rendered using the changed style information.