KR100644719B1 - Method of reproducing subtitle files - Google Patents

Abstract

A method of playing a subtitle is disclosed.

The subtitle reproduction method according to the present invention includes a parsing step of separating and extracting rendering information used for rendering text and control information used for presenting rendered text from text-based subtitle data, and extracted rendering information. And generating a bitmap image for the subtitle text by rendering the subtitle text.

As a result, the output time of each subtitle item included in the text subtitle data can be duplicated, the subtitle file can be easily produced, and the subtitle for the AV stream can be output in more various forms.

Description

How to play subtitles {Method of reproducing subtitle files}

1 is a diagram showing the structure of a text-based subtitle file;

2 is a block diagram of a playback apparatus for playing an information storage medium recording a text-based subtitle;

3 is a detailed block diagram of the text subtitle processing unit 220;

4 is a reference diagram for explaining generating a bitmap image without a presentation engine;

FIG. 5 is a diagram showing an example of correlation between structures in which configuration information, location information, object information, and color information are recorded; FIG.

6A to 6C are diagrams for describing an image generation using one configuration information and one location information for a plurality of subtitles;

7A to 7C are diagrams for describing generating an image using one configuration information and a plurality of location information for a plurality of subtitles;

8A to 8C are diagrams for describing an example in which a plurality of pieces of configuration information are configured for a plurality of subtitles to generate an image so that one image object is included in one piece of configuration information.

The present invention relates to a subtitle, and more particularly, to a subtitle reproducing method for outputting at least one subtitle on a screen at the same time.

Conventional subtitles are created in the form of bitmap images and included in the AV stream. Since it is a bitmap image form, not only is it inconvenient to create a subtitle, but the user has no choice but to manually accept various attributes of the subtitle defined by the subtitle creator. That is, since attributes such as font, font size and font color are already determined and included in the AV stream in the form of a bitmap image, the user cannot arbitrarily change the attributes.

In addition, since the subtitle is compressed and encoded together with the AV stream, the output start time and the output completion time of the subtitle are clearly specified corresponding to the AV stream, and the time for outputting the subtitle bitmap image does not overlap with each other. In other words, one subtitle bitmap image is output at any one time zone.

However, in the recording medium and the playback apparatus recording the text-based subtitles generated separately from the AV stream, the output start time is output since the output start time and output completion time of each subtitle are arbitrarily designated by the producer of the subtitle. And the output completion time may overlap each other between the plurality of subtitles. In other words, two or more subtitles may be output in a certain time interval, and there is a need for a method of processing the same.

Accordingly, an object of the present invention is to provide a method of outputting a subtitle when an output time of a plurality of subtitles is duplicated in an information storage medium on which a text-based subtitle is recorded.

One feature of the present invention for solving the above problems is, in the text subtitle playback method, a control used to present the rendered information and the rendering information used for rendering the text in the text-based subtitle data Parsing step of separating and extracting information, and rendering the sub-title text according to the extracted rendering information to generate a bitmap image for the sub-title text.

The parsing step may further include configuring the control information in accordance with a predetermined information structure format and transmitting the control information to a presentation engine.

The text subtitle reproduction method may further include controlling to output the generated bitmap image directly to the screen using the control information independently of the presentation engine that processes the bitmap subtitle data.

The subtitle data may be a plurality of subtitle data having overlapping output times.

The generating the bitmap image may include generating one bitmap image by generating one piece of configuration information, one piece of location information, and one piece of object information with respect to a plurality of subtitle data having overlapping output times. Can be.

The generating a bitmap image may include generating a bitmap image by generating one configuration information, a plurality of location information, and a plurality of object information with respect to a plurality of sub-title data having an overlapping output time. have.

The bitmap image generating step may generate a bitmap image by generating a plurality of pieces of configuration information, one location information corresponding to each piece of configuration information, and one object information, for a plurality of subtitle data having an overlapping output time. It may include the step.

The bitmap image generating step may include rendering the plurality of sub-title text data by applying the same output style to each other and creating a single page composed of one image.

The step of generating a bitmap image may include applying different output styles to the plurality of sub-title text data to render, and configuring the rendered plurality of images into one page.

The step of generating a bitmap image may include applying different output styles to the plurality of sub-title text data to render and constructing a plurality of pages from the rendered plurality of images.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating the structure of a text-based subtitle file.

The text-based subtitle file 100 includes dialog information 110, presentation information 120, and meta data 130a and 130b.

The dialog information 110 includes subtitle text, the start time of output of the text, the end time of output, the stylegroup or style information to be used for text rendering, and the fade-in / fade-out. Text change effect information such as Out), and a formatting code for the text. Formatting code includes code for bold text, code for italics, code for underscores, code for line breaks, and the like.

The presentation information 120 includes style information to be used for rendering caption text, and is composed of a plurality of style groups. A style group is a collection of styles in which style information is recorded. The style contains information that will be used to render the subtitle text and output the screen. Examples of information include the name of the style, font, text color, background color, text size, line spacing, text output area, start position of text output, output direction, and alignment.

The meta data 130a and 130b are additional information about a moving picture and include information necessary for performing an additional function other than outputting of a subtitle.

2 is a block diagram of a reproduction apparatus for reproducing an information storage medium recording a text-based subtitle.

The text subtitle processing unit 220 renders text in order to process the text-based subtitle. The text subtitle processing unit 220 generates an image to be output by rendering text based on a text subtitle parser 221 for extracting presentation information and dialog information from the subtitle and the extracted presentation information. And a text image generation unit (Text layout / Font Renderer) 222.

The text-based subtitle may be recorded in an information storage medium or in a memory provided in the reproduction device. In FIG. 2, the information storage medium or memory in which the text-based subtitle is recorded is referred to as the subtitle information storage unit 200.

The text-based subtitle file produced corresponding to the video being played and the font data to be used for rendering the subtitle are read from the subtitle information storage unit 200 and stored in the buffer 210. The subtitle file stored in the buffer is transferred to the text subtitle parser 221 to parse information necessary for rendering the subtitle. Subtitle text, font information, and rendering style information necessary for text rendering are transmitted to the text image generation unit 222, and control information of the text subtitle is transmitted to the configuration buffer 233 of the presentation engine 230. The control information is information for constructing a screen with subtitles, and includes information such as an output area and an output start position.

The text image generator 222 renders a text subtitle using text rendering information transmitted from the text subtitle parser 221 and font data transmitted from the buffer 210 to generate a bitmap image, and each item of the subtitle. A subtitle page is configured by specifying an output start time and an output completion time, and then transmitted to the object buffer 234 of the presentation engine 230.

Meanwhile, a subtitle in the form of a bitmap image read from the subtitle information storage unit 200 is input to a coded data buffer 231 and processed by the graphic processor 232 to generate a bitmap image. . The generated bitmap image is transmitted to the object buffer 234, and the control information of the bitmap image is transmitted to the configuration buffer 233. The control information specifies a time and a position at which the bitmap image stored in the object buffer 234 is output to the graphic plane 240, and the CLUT (Color) in which the color information to be applied to the bitmap image output to the graphic plane 240 is recorded. Lookup Table (250).

The configuration buffer 233 receives the object configuration information transmitted from the text subtitle parser 221 and the bitmap subtitle data processed by the graphic processor 232 and transmits the screen output control information to the graphic controller 235. . The object buffer 234 combines the bitmap subtitle data processed by the graphic processor 232 and the rendered text subtitle object received from the text image generator 222 into a graphic plane 240 to form the CLUT 250. Reference to the output to the display device.

3 is a detailed block diagram of the text subtitle processing unit 220.

The subtitle, which is text-based subtitle file information, is input to the text subtitle parser 221, the text subtitle parser 221 parses the input subtitle, and the subtitle control information is transmitted to the presentation engine 230. The text rendering related information is transmitted to the text image generator 222. The text image generator 222 receives information related to text rendering from the text subtitle parser 221, and control information of the caption item is provided in an element control buffer 290, and caption data is a text data buffer. In the Text Data Buffer 291, the style information to be used for rendering is stored in the Style Data Buffer 292, and the font data to be used for rendering the text is stored in the Font Data Buffer 293. .

The control information stored in the element control buffer 290 may be a formatting code, etc. The formatting code includes a code for bold text, an italic code, an underline code, a line break code, and the like. Doing. The text data stored in the text data buffer 291 is text data to be output as subtitles. The style data stored in the style data buffer 292 may be data about a font, a text color, a background color, a text size, a line spacing, a text output area, a start position of a text output, an output direction, an alignment method, and the like. The text renderer 294 generates a subtitle image by referring to the information recorded in each buffer and transmits the subtitle image to the presentation engine 230.

4 is a reference diagram for describing generating a bitmap image without a presentation engine.

That is, another exemplary embodiment of the operation of the text subtitle processing unit is described, and the text subtitle control unit 410 is provided instead of the presentation engine. Here, the text image generating unit 222 generates configuration information, location information, object information, and color information, and creates a bitmap image based on this. The text subtitle control unit 410 receives the object configuration information from the text subtitle processing unit 220 and directly transfers the bitmap image generated by the text image generation unit 222 to the graphic plane 240 and the CLUT 250. The text image generation unit 222 is controlled to output.

5 is a diagram illustrating an example of correlation between structures in which configuration information, location information, object information, and color information are recorded.

The subtitles output on the screen are organized in page units. This page may contain data used for other purposes besides the subtitle. Information that records information used to compose one page is called configuration information. The configuration information includes output time information indicating an output time of a page, an object information reference value indicating an image object to be output, and an output position of an object. Location information reference value indicating a color information reference value indicating color information on the object.

Correlation of each of the information shown in FIG. 5 is an embodiment of the information configuration, and it is also possible to configure the correlation between the position information, the object information, and the color information in a format different from that of FIG. 5.

Referring to FIG. 5, one page may include one or more regions in which an image is output on the screen. These areas are divided by location information reference values. The positional information is a structure that records information necessary to form these areas. The position information includes information about horizontal and vertical coordinates, widths, and heights of each region. The object information records object data on the screen. The object information includes data type information and object data of the object.

The operation of the text subtitle processing unit will be described by way of example. The text subtitle processing unit may include the above-described configuration information, location information, and object information for each rendered subtitle image to be output on the screen to provide a text-based subtitle. And color information. The generated configuration information, location information, object information, and color information are transmitted to the presentation engine.

As described above, in reproducing an information storage medium on which subtitles made in text form are recorded, there are various methods of outputting one or more subtitles at the same time.

In the first method, a text subtitle processor generates a new image for a plurality of subtitles whose output times of subtitle text overlap, and presents a subtitle composed of objects which are made to be output in one position information in one composition information. How to send to the presentation engine.

The second method is a method in which each subtitle whose output time of the caption text overlaps has different position information. That is, the text subtitle processing unit is a method of creating an image using different positional information in one piece of configuration information and transmitting the same to the presentation engine for a plurality of subtitles whose output times of the subtitle text overlap.

The third method is to create subtitles with overlapping output time of subtitle text using different composition information. That is, the text subtitle processing unit is configured to generate different configuration information for each subtitle for a plurality of subtitles in which the output time of the subtitles overlaps, so that only one object is included in one configuration information. Hereinafter, each method will be described in more detail with reference to the accompanying drawings.

6A to 6C are diagrams for describing an image generation using one configuration information and one location information for a plurality of subtitles.

6A defines a style "Script" as style information to be used for rendering subtitle text. Referring to FIG. 6A, the style "Script" uses a font called "Arial.ttf", the font color is "black", the background color is "white", the font size is "16pt", and the reference position of the text is coordinate (x , y), the alignment is "center", the output direction is "left-to-right-top-to-bottom", the output area is "left, top, width, height", and the line spacing is "40px". have.

6B defines the subtitle text 610, 620, 630 rendered using the style "Script". Referring to FIG. 6B, the subtitle text Hello 610 is output from time "00:10:00" to "00:15:00", and the subtitle text Subtitle 620 is time "00:12:00". From "00:17:00", the subtitle text World 630 is output from "00:14:00" to "00:19:00". Therefore, two or three subtitle texts are output from the time "00:12:00" to "00:17:00". Where "<br>" is information indicating a line break. By using the <br> tag, you can prevent multiple subtitles from being overlaid on one area even if you use a single style.

6C is a diagram illustrating a result of outputting a subtitle defined by FIGS. 6A and 6B. Accordingly, the data stored in each buffer of the text subtitle processing unit for each time zone will be described in detail as follows.

① Until time "00:10:00": Configuration information output including blank subtitle image

Element Control Data Buffer: Empty

Text data buffer: empty

Style data buffer: style "script" information

Font data buffer: Font information of "Arial.ttf"

② From "00:10:00" to "00:12:00": Outputs the configuration information including the rendered image of the subtitle text Hello (610)

Element control data buffer: control information for the subtitle text Hello 610

Text data buffer: "Hello"

Style data buffer: style "script" information

Font data buffer: Font information of "Arial.ttf"

③ From time "00:12:00" to "00:14:00": Configuration information output including rendered images of subtitle text Hello (610) and subtitle text Subtitle (620)

Element control data buffer: control information for subtitle text Hello (610) and subtitle text Subtitle (620)

Text Data Buffers: "Hello" and "<br> Subtitle"

Style data buffer: style "script" information

Font data buffer: Font information of "Arial.ttf"

④ From time "00:14:00" to "00:15:00": configuration including rendered images of subtitle text Hello (610), subtitle text Subtitle (620), subtitle text World (630) Information output

Element control data buffer: control information for subtitle text Hello 610, subtitle text Subtitle 620, and subtitle text World 630

Text Data Buffers: "Hello" and "<br> Subtitle" and "<br> <br> World"

Style data buffer: style "script" information

Font data buffer: Font information of "Arial.ttf"

⑤ From time "00:15:00" to "00:17:00": Configuration information including the rendered image of the subtitle text Subtitle (620) and the sub title text World (630)

Element control data buffer: control information for the subtitle text Subtitle 620 and the sub title text World 630

Text Data Buffers: "<br> Subtitle" and "<br> <br> World"

Style data buffer: style "script" information

Font data buffer: Font information of "Arial.ttf"

⑥ From time "00:17:00" to "00:19:00": Output of configuration information including the rendered image of the subtitle text World 630

Element control data buffer: control information for the subtitle text world 630

Text data buffer: "<br> <br> World"

Style data buffer: style "script" information

Font data buffer: Font information of "Arial.ttf"

⑦ Until time "00:19:00": Configuration information output including blank subtitle image

Element Control Data Buffer: Empty

Text data buffer: empty

Style data buffer: style "script" information

Font data buffer: Font information of "Arial.ttf"

As can be seen in the output process of the subtitle, the first method generates one subtitle image by applying the same style to a plurality of subtitle items having duplicate output times, and generates one configuration information to include the same. To the presentation engine. At this time, page_time_out, which is a time when the transmitted configuration information disappears from the screen, is a time when a subtitle for which output is completed last disappears or a time when a new sub title is added among a plurality of sub titles having duplicate output times.

The output subtitle is a text subtitle in consideration of the time (T _decoding ) of _{decoding the} subtitle in the text subtitle processing unit and the time (T _composition ) required for the rendered subtitle to be output from the object buffer to the graphics plane. Title processing must be performed quickly. If the time when the subtitle is output from the playback apparatus in the text subtitle processing unit is called T _start , and the time when the sub title arrives in the text subtitle processing unit is called T _arrival , the correlation between these times is as shown in Equation 1 below. .

Referring to Equation 1, it can be seen how quickly the text subtitle should be processed. T _decoding is a time required to render a subtitle to be output, generate configuration information including the rendered object, and transmit the configuration information to the object buffer. Sub having the output time of T _start title should be at least T _decoding and T _composition plus the previous time by starting the process. T _decoding is a time _obtained by adding T _rendering information, which is a time for rendering caption text to be transmitted to an object buffer, and T _{construction information generation} , which is a time for generating configuration information including a rendered object and transmitting the same to the graphics plane. And T _char is the time it takes to render a character, so T _rendering is the sum of the time it takes to render each character.

And, the size of the object buffer must be greater than or equal to the size of the object. Where the size of the object is the sum of the sizes of each character data. Therefore, the number of characters constituting one subtitle is limited to the number of characters that can be stored in the object buffer. In addition, since the object buffer can store a plurality of subtitles, in this case, the number of characters constituting the plurality of subtitles is also limited to the number of characters that can be stored in the object buffer.

7A to 7C are diagrams for describing an image generation using one piece of configuration information and a plurality of location information for a plurality of subtitles.

7A defines styles "Script1", "Script2", and "Script3" as style information to be used for rendering subtitle text. Referring to FIG. 7A, the three styles use the font "Arial.ttf" and the font color is "black", the background color is "white", the font size is "16pt", the alignment method is "center", and the output direction is " left-to-right-top-to-bottom ", line spacing" 40px ". As a reference position of the subtitle text, "Script1" has coordinates (x1, y1), "Script2" has coordinates (x2, y2), and "Script3" has coordinates (x3, y3). As the output area, it can be seen that Script1 is "left1, top1, width1, height1", Script2 is "left2, top2, width2, height2", and Script3 is "left3, top3, width3, height3".

FIG. 7B defines the subtitle text 710, 720, 730 rendered using the styles "Script1", "Script2", "Script3". Referring to FIG. 7B, the subtitle text Hello 710 uses style "Script1" and outputs from "00:10:00" to "00:15:00", and the subtitle text Subtitle 720 is styled. Using "Script2" and outputting from "00:12:00" to "00:17:00", subtitle text World (730) uses style "Script3" and starts from "00:14:00" It can be seen that "00:19:00" is output. Therefore, two or three subtitle texts are output from the time "00:12:00" to "00:17:00". In this case, the newline tag <br> is unnecessary because you used different scripts.

7C is a diagram illustrating a result of outputting a caption defined by FIGS. 7A and 7B. Accordingly, the data stored in each buffer of the text subtitle processing unit for each time zone will be described in detail as follows.

① Until time "00:10:00": Configuration information output including blank subtitle image

Element Control Data Buffer: Empty

Text data buffer: empty

Style data buffer: empty

Font data buffer: Font information of "Arial.ttf"

② Time "00:10:00" to "00:12:00": Configuration information output including the rendered image of the subtitle text Hello 710

Element control data buffer: control information for the subtitle text Hello 710

Text data buffer: "Hello"

Style data buffer: style "Script1" information

Font data buffer: Font information of "Arial.ttf"

③ From time "00:12:00" to "00:14:00": Configuration information output including subtitle text Hello (710) and subtitle text Subtitle (720)

Element control data buffer: control information for the subtitle text Hello (710) and the subtitle text Subtitle (720)

Text Data Buffers: "Hello" and "Subtitle"

Style data buffer: style "Script1" and style "Script2" information

Font data buffer: Font information of "Arial.ttf"

④ Time "00:14:00" to "00:15:00": Configuration information output including subtitle text Hello (710), subtitle text Subtitle (720) and subtitle text World (730)

Element control data buffer: control information for subtitle text Hello 710, subtitle text Subtitle 720, and subtitle text World 730

Text data buffer: "Hello" and "Subtitle" and "World"

Style data buffer: style "Script1" and style "Script2" and style "Script3" information

Font data buffer: Font information of "Arial.ttf"

⑤ From "00:15:00" to "00:17:00": Configuration information output including subtitle text Subtitle 720 and sub title text World 730

Element control data buffer: control information for the subtitle text Subtitle 720 and the sub title text World 730

Text Data Buffers: "Subtitle" and "World"

Style data buffer: style "Script2" and style "Script3" information

Font data buffer: Font information of "Arial.ttf"

⑥ From time "00:17:00" to "00:19:00": Configuration information output including subtitle text World 730

Element control data buffer: control information for the subtitle text world 730

Text data buffer: "World"

Style data buffer: style "Script3" information

Font data buffer: Font information of "Arial.ttf"

⑦ Until time "00:19:00": Configuration information output including blank subtitle image

Element Control Data Buffer: Empty

Text data buffer: empty

Style data buffer: empty

Font data buffer: Font information of "Arial.ttf"

In the second method described above, subtitle images are generated for each subtitle item by applying different styles to a plurality of subtitle items having duplicate output times, and one piece of configuration information including them is generated and transmitted to the presentation engine. . The processing time of the text subtitle is the same as in the first method. That is, the output subtitle is the text subtitle in consideration of the time (T _decoding ) for decoding the subtitle in the text subtitle processing unit and the time (T _composition ) required for the rendered subtitle to be output from the object buffer to the graphics plane. Title processing must be performed quickly. In this case, however, since there are a plurality of objects, the rendering time is the sum of the time taken for each of these objects to be rendered, and is calculated by the following equation (2).

The limit on the number of characters of the subtitle text that can be stored in the object buffer is the same as in the first method.

8A to 8C are diagrams for describing an example in which a plurality of pieces of configuration information are configured for a plurality of subtitles to generate an image so that one image object is included in one piece of configuration information.

8A defines styles "Script1", "Script2", and "Script3" as style information used for rendering caption text. Referring to FIG. 8A, three styles use the font "Arial.ttf", the font color is "black", the background color is "white", the font size is "16pt", the alignment method is "center", and the output direction is " left-to-right-top-to-bottom "," 40px "in line spacing. As a reference position of the text image, "Script1" has coordinates (x1, y1), "Script2" has coordinates (x2, y2), and "Script3" has coordinates (x3, y3). "" Has left1, top1, width1, height1 "," Script2 "has" left2, top2, width2, height2 ", and" Script3 "has" left3, top3, width3, height3 ".

8B defines subtitle text 810, 820, 830 rendered using styles "Script1", "Script2", "Script3". Referring to FIG. 8B, the subtitle text Hello 810 uses style "Script1" and outputs from "00:10:00" to "00:15:00", and the subtitle text Subtitle 820 is styled. Using "Script2" and outputting from "00:12:00" to "00:17:00", subtitle text World (830) uses style "Script3" and starts from "00:14:00" It can be seen that "00:19:00" is output. Therefore, two or three subtitle texts overlap from "00:12:00" to "00:17:00".

8C is a diagram illustrating a result of outputting a caption defined by FIGS. 8A and 8B. Accordingly, the data stored in each buffer of the text subtitle processing unit for each time zone will be described in detail as follows.

① At time "00:00:00": Configuration information output including blank subtitle image

Element Control Data Buffer: Empty

Text data buffer: empty

Style data buffer: empty

Font data buffer: Font information of "Arial.ttf"

② At time "00:10:00": Outputs the configuration information including the rendered image of the subtitle text Hello 810

Element control data buffer: control information for the subtitle text Hello 810

Text data buffer: "Hello"

Style data buffer: style "Script1" information

Font data buffer: Font information of "Arial.ttf"

③ At time "00:12:00": Outputs the configuration information including the subtitle text Hello 810 and the configuration information including the subtitle text Subtitle 820, respectively.

Element control data buffer: load control information for subtitle text Subtitle (820)

Text data buffer: "Subtitle"

Style data buffer: style "Script2" information

Font data buffer: Font information of "Arial.ttf"

④ at time "00:14:00": configuration information including subtitle text Hello 810 and configuration information including subtitle text Subtitle 820 and configuration information including subtitle text World 830. Each output

Element Control Data Buffer: Load Control Information for Subtitle Text World 830

Text data buffer: "World"

Style data buffer: style "Script3" information

Font data buffer: Font information of "Arial.ttf"

⑤ After time “00:15:00”: The text subtitle processing unit does not operate until it prepares to output the next subtitle item to be output after the time “00:19:00”. Therefore, the change of the subtitle output between the time "00:15:00" and the time "00:19:00" presents the configuration information for each of the subtitles Hello, Subtitle, and World received from the text subtitle processing unit. This is done by the engine controlling.

That is, at time “00:15:00”, the presentation engine removes the configuration information for the subtitle Hello and the bitmap image object from the configuration buffer and the object buffer, and outputs only the configuration information for the subtitle Subtitle, World on the screen. . At time "00:17:00", the presentation engine removes the configuration information for the subtitle Subtitle and the bitmap image object from the configuration buffer and the object buffer, and outputs only the configuration information for the subtitle World on the screen. In addition, at time "00:19:00", the presentation engine removes the configuration information and the bitmap image object for the subtitle world from the configuration buffer and the object buffer and no longer outputs the subtitle on the screen.

In the third method, one subtitle image is generated for each subtitle item by applying different styles to a plurality of subtitle items having overlapping output times, and one configuration information is generated for one subtitle image. The information is sent to the presentation engine. The output time of the text subtitle is the same as in the first method. In the first and second methods, since one configuration information is composed and output for a plurality of subtitle items having overlapping output times, only a processing time for one configuration information is considered at a time, whereas in the third method, each subtitle item is considered. Since one piece of configuration information is configured, a plurality of pieces of configuration information are generated and output. Therefore, in the third method, the processing start time of the subtitle item should be assumed that a plurality of pieces of configuration information are simultaneously generated and output for a plurality of subtitles having the same output start time, which is the worst case. It is explained by 3.

The T _{configuration information generation, which} is a time for generating a plurality of configuration information, is represented as the sum of the T _{configuration informations} , which is the time for generating the configuration information for one subtitle. T _rendering is a time for generating a plurality of objects by rendering a plurality of subtitles, and is expressed as a sum of T _{OBJs which} are rendering times for one subtitle. T _OBJ is the time taken to render one subtitle, which is the sum of the T _chars that are the rendering times of each character included in the subtitle. Referring to Equation 3, in order for a plurality of subtitles including a plurality of characters to be output at the same time, at least the sum of the time required to render all the characters included in each subtitle and to configure and output the plurality of configuration information. It can be seen that the difference between the output time of this subtitle and the time at which the subtitle starts to be processed in the text subtitle processing unit.

The limit of the number of characters of the subtitle text that can be stored in the object buffer is the same as that of the first method and the second method.

As in the third method described above, the information storage medium and the playback device configured to simultaneously support the output of a plurality of pieces of configuration information simultaneously output text-based subtitles and bitmap images other than subtitles on a screen. You may.

The data encoded with the AV stream includes video data, audio data, sub-titles in bitmap format, and bitmap images that are not subtitles. For example, a bitmap image that is not a subtitle, an image such as ⑮ can be displayed at the top of the screen to indicate that the program can be watched over 15 years in a TV broadcast. In the past, only one piece of configuration information is output to the screen at any one time. Therefore, in order to simultaneously output a bitmap subtitle and other bitmap images, an area for outputting a subtitle and an area for outputting other bitmap images are provided. The configuration information is defined separately and output in each area.

Thus, if the user turns off the output because the user does not want the output of the subtitle, the decoder stops decoding the subtitle only. Therefore, the subtitle data is not transferred to the object buffer, so the subtitle disappears and only the bitmap image, not the subtitle, is continuously output.

If the text subtitle processing unit generates an image for the subtitle with one piece of configuration information and outputs it to the presentation engine to output the subtitle, when the output of the subtitle is turned off, the bits other than the subtitle recorded in the AV stream are turned off. No map image is printed. Therefore, as described in the third method of the present invention, when a plurality of pieces of configuration information can be output on the screen at the same time, when the text subtitle is selected instead of the bitmap subtitle, It is possible to continue to output the remaining images except for the bitmap subtitle, and to output the subtitle using the configuration information generated by the text subtitle processing unit. That is, the text subtitle can be output and at the same time, other bitmap images other than the subtitle can also be output on the screen.

The subtitle output method described above can be created by a computer program. Codes and code segments constituting the program can be easily inferred by a computer programmer in the art. In addition, the program is stored in a computer readable media, and read and executed by a computer to implement the reference picture determination method and the motion compensation method. The information storage medium includes a magnetic recording medium, an optical recording medium, and a carrier wave medium.

As described above, according to the present invention, the subtitle file can be easily produced, and the subtitle for the AV stream can be output in more various forms.

Claims (10)

A parsing step of separately extracting rendering information used for rendering the text from the text-based subtitle data and control information used for presenting the rendered text; And rendering a subtitle text according to the extracted rendering information to generate a bitmap image for the subtitle text. The method of claim 1, wherein the parsing step And constructing the control information in accordance with a predetermined information structure format and transmitting the control information to a presentation engine. The method of claim 1, And controlling to output the generated bitmap image directly to the screen by using the control information independently of the presentation engine that processes the bitmap subtitle data. The method of claim 1, And the sub title data is a plurality of sub title data having an overlapping output time. The method of claim 1, wherein the bitmap image generating step And generating and outputting a bitmap image by generating one configuration information, one location information, and one object information for a plurality of sub title data having overlapping output times. Way. The method of claim 1, wherein the bitmap image generating step And generating a bitmap image by generating one configuration information, a plurality of location information, and a plurality of object information for a plurality of subtitle data having an overlapping output time. . The method of claim 1, wherein the bitmap image generating step And generating a bitmap image by generating a plurality of configuration information, one location information corresponding to each configuration information, and one object information, for a plurality of subtitle data having overlapping output times. How to play a text subtitle. The method of claim 1, wherein the bitmap image generating step And applying the same output style to the plurality of subtitle text data and rendering the same, and forming one page composed of one image. The method of claim 1, wherein the bitmap image generating step And applying a different output style to the plurality of sub-title text data and rendering the plurality of sub-title text data, and configuring the rendered plurality of images into one page. The method of claim 1, wherein the bitmap image generating step And applying a different output style to a plurality of the sub-title text data and rendering a plurality of pages with the rendered plurality of images.

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