Recording medium and method and apparatus for decoding text subtitle streams
At least one text subtitle stream is recorded on a recording medium. Each text subtitle stream includes a dialog style segment defining a set of region styles and at least one dialog presentation segment. Each dialog presentation segment contains at least one region of dialog text and being linked to at least one of the set of region styles. The dialog style segment further defines a set of user control styles for each region style. Each user control style is selectable by a user and is configured to change at least one of region presentation properties specified by a corresponding region style.
This is a continuation application of application Ser. No. 11/033,494 filed Jan. 12, 2005, the entire contents of which are hereby incorporated by reference.
This application claims the benefit of U.S. Provisional Application No. 60/542,850, filed on Feb. 10, 2004; U.S. Provisional Application No. 60/542,852, filed on Feb. 10, 2004; and U.S. Provisional Application No. 60/543,328, filed on Feb. 11, 2004, the entire contents of which are hereby incorporated by reference. This application also claims the benefit of Korean Patent Application No. 10-2004-0017935, filed on Mar. 17, 2004, which is hereby incorporated by reference as if fully set forth herein.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention relates to a recording medium and a method and apparatus for decoding a text subtitle stream recorded on a recording medium.
2. Discussion of the Related Art
Optical discs are widely used as an optical recording medium for recording mass data. Presently, among a wide range of optical discs, a new high-density digital video disc (hereinafter referred to as “HD-DVD”), such as a Blu-ray Disc (hereafter referred to as “BD”), is under development for recording high definition video and audio data. Currently, global standard technical specifications of BDs, which are known to be the next generation HD-DVD technology, are under establishment as a next generation optical recording solution that is able to have data significantly surpassing the conventional DVD, along with many other digital apparatuses.
Accordingly, optical reproducing apparatuses having the Blu-ray Disc (BD) standards applied thereto are also being developed. However, since the Blu-ray Disc (BD) standards are yet to be completed, there have been many difficulties in developing a complete optical reproducing apparatus. Particularly, in order to effectively reproduce the data from the Blu-ray Disc (BD), not only should the main AV data as well as various data required for a user's convenience, such as subtitle information as the supplementary data related to the main AV data, be provided, but also managing information for reproducing the main data and the subtitle data recorded in the optical disc should be systemized and provided.
However, in the present Blu-ray Disc (BD) standards, since the standards of the supplementary data, particularly the subtitle information, are not completely consolidated, there are many restrictions in the full-scale development of a Blu-ray Disc (BD) basis optical reproducing apparatus. And, such restrictions cause problems in providing the supplementary data such as subtitles to the user.
SUMMARY OF THE INVENTIONAccordingly, the present invention is directed to a text subtitle decoder and a method for decoding text subtitle streams recorded on a recording medium that substantially obviates one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a recording medium including a dialog style segment defining a set of user control styles, each of which is able to change at least one of region presentation properties specified by a region style.
Another object of the present invention is to provide a method and an apparatus for decoding a text subtitle stream by using a user control style which changes at least one of the region presentation properties specified by a region style.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a recording medium includes a data area storing at least one text subtitle stream, each of which includes a dialog style segment defining a set of region styles to be applied to at least one region of dialog text. Each text subtitle stream may further include at least one dialog presentation segment, each of which contains at least one region of dialog text and is linked to at least one of the set of region styles. The dialog style segment further defines a set of user control styles for each region style, where each user control style is selectable and is configured to change at least one of region presentation properties specified by a corresponding region style. For example, each user control style may specify a direction and a magnitude of a change in at least one of a region horizontal position, a region vertical position, a text horizontal position, a text vertical position, a line space, and a font size, all which are specified in the corresponding region style.
In another aspect of the present invention, a method and an apparatus for decoding a text subtitle stream recorded on a recording medium are provided. A subtitle loading buffer loads the text subtitle stream, which includes a dialog style segment defining a set of region styles and at least on dialog presentation segment. Each dialog presentation contains at least one region of dialog text and is linked to at least one of the set of region styles. The dialog style segment further defines a set of user control styles for each region, where each user control style is selectable and is configured to change at least one of region presentation properties specified by a corresponding region style. A text subtitle decoder is able to decode each dialog presentation segment using the linked region style and one of the set of user control styles defined in the dialog presentation segment.
Each user control style may specify a direction and a magnitude of a change in the region presentation properties specified by the corresponding region style. The region presentation properties include at least one of a region horizontal position, a region vertical position, a text horizontal position, a text vertical position, a line space, and a font size, which are specified in the corresponding region style.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGSThe accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings;
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
In this detailed description, main data represent audio/video (AV) data that belong to a title (e.g., a movie title) recorded in an optical disc by an author. In general, the AV data are recorded in MPEG2 format and are often referred to as AV streams or main AV streams. In addition, supplementary data represent all other data required for reproducing the main data, examples of which are text subtitle streams, interactive graphic streams, presentation graphic streams, and supplementary audio streams (e.g., for a browsable slideshow). Theses supplementary data streams may be recorded in MPEG2 format or in any other data format. They could be multiplexed with the AV streams or could exist as independent data files within the optical disc.
A subtitle represents caption information corresponding to video (image) data being reproduced, and it may be represented in a predetermined language. For example, when a user selects an option for viewing one of a plurality of subtitles represented in various languages while viewing images on a display screen, the caption information corresponding to the selected subtitle is displayed on a predetermined portion of the display screen. If the displayed caption information is text data (e.g., characters), the selected subtitle is often called a text subtitle. According to one aspect of the present invention, a plurality of text subtitle streams in MPEG2 format may be recorded in an optical disc, and they may exist as a plurality of independent stream files. Each text subtitle stream file includes text data for a text subtitle and reproduction control data required for reproduction of the text data. According to another aspect of the present invention, only a single text subtitle stream in MPEG2 format may be recorded in an optical disc.
The file directories included in each BD directory are a stream directory (STREAM), a clip information directory (CLIPINF), a playlist directory (PLAYLIST), and an auxiliary data directory (AUX DATA). First of all, the stream directory (STREAM) includes audio/video (AV) stream files having a particular data format. For example, the AV stream files may be in the form of MPEG2 transport packets and be named as “*.m2ts”, as shown in
Next, the clip information directory (CLPINF) includes clip information files that correspond to the stream files (AV or text subtitle) included in the stream directory, respectively. Each clip information file contains property and reproduction timing information of a corresponding stream file. For example, A clip information file may includes mapping information, in which presentation time stamps (PTS) and source packet numbers (SPN) are one-to-one mapped by an entry point map (EPM). Using the mapping information, a particular location of a stream file may be determined from timing information (In-Time and Out-Time) provided by a PlayItem or SubPlayItem, which will be discussed later in more details. In the industry standard, each pair of a stream file and its corresponding clip information file is designated as a clip. For example, 01000.clpi included in CLIPINF includes property and reproduction timing information of 01000.m2ts included in STREAM, and 01000.clpi and 01000.m2ts form a clip.
Referring back to
Lastly, the auxiliary data directory (AUX DATA) may include supplementary data stream files, examples of which are font files (e.g., *.font or *.otf), pop-up menu files (not illustrated), and sound files (e.g., Sound.bdmv) for generating click sound. The text subtitle stream files mentioned earlier may be included in the auxiliary data directory instead of the stream directory.
In addition,
Region style information defines a region style (global style) which is applied to an entire region of a dialog. For example, the region style information may contain at least one of a region position, region size, font color, background color, text flow, text alignment, line space, font name, font style, and font size of the region. For example, two different region styles are applied to region 1 and region 2, as shown in
On the other hand, inline style information defines an inline style (local style) which is applied to a particular portion of text strings included in a region. For example, the inline style information may contain at least one of a font type, font size, font style, and font color. The particular portion of text strings may be an entire text line within a region or a particular portion of the text line. Referring to
All the data included in a text subtitle stream may be classified into three types of data based on their basic functions. For example, the data could be classified into dialog text data, composition information, and rendering information, as shown in
A DSU includes a set of region style information (dialog style set) defining a limited number of author-defined region styles, respectively. For example, the maximum number of the region styles defined in a DSU may be limited to 60, and the region styles may be identified by their region style identifications (region_style_id). Therefore, an author stores a DSU defining only a limited number of region styles in an optical disc. The region styles are used by a disc player when reproducing text subtitle streams recorded on the optical disc. Alternatively, the disc player may use other region styles defined by an additional set of style information, which may be provided from other source. An example of the source is a local data storage included in the disc player. As a result, the subtitle regions reproduced from the text subtitle streams recorded on the optical disc can have a variety of region styles.
Referring to
Reference will now be made in detail to specific region presentation properties defined in each region style (region_style ( )). A region horizontal position (region_horizontal_position) specifies the horizontal address of the top left pixel of a region in a graphics plane, and a region vertical position (region_vertical_position) specifies the vertical address of the top left pixel of the region in the graphics plane. In addition, a region width (region_width) specifies the horizontal length of the region rectangle from the region horizontal position, and a region height (region_height) specifies the vertical length of the region rectangle from the region vertical position. A region background color index (region_bg_color_index) specifies an index value indicating the background color of the region.
In addition, a text horizontal position (text_horizontal_position) specifies the horizontal address of an origin of text in the region, and a text vertical position (text_vertical_position) specifies the vertical address of the text origin in the region. A text flow (text_flow) specifies at least one of character progression (left-to-right or right-to-left) and line progression (top-to-bottom or bottom-to-top) in the region. A text alignment (text_alignment) specifies alignment (left, center, or right) of rendered text in the region. When a dialog has more than one regions, the same text flow must be applied to all the regions in order to prevent the viewers' confusion. Referring back to
The player style flag (player_style_flag) shown in
According to
Referring to
Some of the characteristic features of the user changeable style set according to the present invention are as follows. First, a set of user control styles are defined for each of a set of region styles defined in a dialog style unit, and the number of the set of control styles are fixed. Therefore, the numbers of the user control styles defined for two different region styles, respectively, are identical. The number of the set of user control styles to be used when reproducing each region of dialog text is fixed. Next, the set of user control. styles are identified by different user style IDs, respectively. Third, all the changes in the region presentation properties are defined in combination by a single user control style. For example, the region horizontal position and font size are not changed separately by two distinct user control styles. They are changed in combination by a single user control style. Fourth, a change of a certain property is represented with its direction and magnitude rather than with an actual property value. The actual property value may be obtained by applying the magnitude (delta) and direction of the change to the original property value defined in a region style.
In conclusion, when an author records main AV streams in an optical disc, the author also records at least one text subtitle stream. Each text subtitle stream includes a DSU defining a set of dialog styles and a plurality of DPUs. The set of region styles have different region style IDs. The DSU further defines a set of user control styles for each region style, where the user control styles have different user style IDs. Each user control style is configured to change at least one of the author-defined region presentation properties which are specified by a corresponding region style. In addition, the dialog style set includes a player style flag indicating whether the author permitted a player to generate and/or use its own set of player styles for a text subtitle in additional to the author-defined style set.
Reference will now be made in detail to an apparatus for decoding man AV streams and text subtitle streams according to the present invention, an example of which is illustrated in
The text subtitle streams may be extracted from an optical disc or from an additional external source, as shown in
Referring back to
When the text subtitle decoding part 40 receives a text subtitle stream supporting a single language from the switch 6, an entire portion of the text subtitle stream may be preloaded into a subtitle preloading buffer (SPB) 41 at once. Alternatively, when there are more than one text subtitle streams for supporting multi-languages, all the text subtitle streams may be preloaded into the SPB 41 at once. Therefore, the size of the SPB 41 should be determined based on a total number of text subtitle stream files received from the switch 6. For example, the size of the SPB 41 should be greater than or equal to 0.5 megabytes for preloading a 0.5 megabyte text subtitle stream file. In addition, in order to ensure seamless presentation of a text subtitle when a user switches among two 0.5 megabyte text subtitle stream files, the size of the SPB 41 should be greater than or equal to 1 megabytes. The size of the SPB 41 should be large enough to preload all the required text subtitle stream files at once.
The text subtitle decoding part 40 shown in
The text subtitle decoding part 40 further includes a local data storage 45 which stores a player style set defining a set of player styles to be selectively used when reproducing a text subtitle stream preloaded in the SPB 41. In addition, the local data storage 45 may further store a user changeable set specifying a set of user control styles to be selectively used when reproducing the text subtitle stream. This user changeable set may be similar to the user changeable set included in a DSU, an example of which is shown in
In first aspect of the present invention, each player style represents a region style specifying a complete set of region presentation properties for a region of dialog text, examples of which are a region horizontal position, region vertical position, region width, region height, region background color index, text horizontal position, text vertical position, text flow, text alignment, line space, font identification, font style, font size, and font color index. In this case, the set of player styles stored in the local data storage 45 is used independent of a set of region styles defined in a DSU.
In second aspect of the present invention, each player style is configured to redefine at least one of region presentation properties which are initially defined by a region style defined in a DSU. For example, if a region style defined in the DSU defines a complete set of region presentation properties including font identification and a player style redefines the font identification, then the redefined font identification and all other properties specified by the region style are used in combination.
In third aspect of the present invention, each player style may be configured to change at least one of region presentation properties which are initially defined by a region style defined in a DSU. For example, a player style may specify a direction and a magnitude of a change in a region horizontal position defined in the region style. In this case, the player style set is similar to the user changeable set, an example of which is illustrated in
In addition, when the text subtitle decoder 42 decodes a DPU, it may use a region style identified by a region style identifier included in the DPU. If a user wises to change this region style, he or she may input a command for changing the region style. By selecting one of a set of user control styles, which are defined by a user-changeable style set defined in a DSU, at least one of the region horizontal position, region vertical position, and font size may be changed.
The apparatus shown in
Lastly, the apparatus shown in
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
According to the present invention, a plurality of user control styles are defined for each region style defined in a dialog style segment. Each user control style is selectable by a user and is configured to change the region presentation properties specified by a corresponding region style. Therefore, a user can have options of selecting one of a variety of user control styles.
Claims
1. A method for reproducing at least one text subtitle stream, the method comprising:
- receiving the text subtitle stream from external source, each text subtitle stream including a style segment defining region style to be applied to at least one region, the style segment further defining at least one set of user control style for each region style, each set of user control style being selectable and configured to change at least one of region presentation properties specified by a corresponding region style; and
- decoding the text subtitle stream using the style segment defining the region style and the at least one set of user control style.
2. The method of claim 1, wherein the style segment includes a data field indicating a number of the region styles.
3. The method of claim 2, wherein the number of region styles is less than or equal to 60.
4. The method of claim 1, wherein the style segment includes a data field indicating a number of the set of user control styles defined in the style segment for each region style.
5. The method of claim 4, wherein the number of the set of user control styles defined for each region style is less than or equal to 25.
6. The method of claim 1, wherein each user control style specifies a direction and a magnitude of a change in the at least one of region presentation properties specified by the corresponding region style.
7. The method of claim 1, wherein the region presentation properties include at least one of a region horizontal position, a region vertical position, a text horizontal position, a text vertical position, a line space, and a font size.
8. The method of claim 1, wherein each user control style specifies a direction and a magnitude of a change in at least one of a region horizontal position, a region vertical position, a text horizontal position, a text vertical position, a line space, and a font size, which are specified in the corresponding region style.
9. A method for reproducing at least one text subtitle stream, the method comprising:
- receiving the text subtitle stream from external source, the text subtitle stream including a style segment defining region styles and at least one presentation segment, each presentation segment containing at least one region and being linked to at least one of the region styles, the style segment further defining at least one set of user control styles for each region style, each user control style configured to change at least one of region presentation properties specified by a corresponding region style; and
- decoding the presentation segment using the linked region style and the user control styles.
10. A method for reproducing at least one text subtitle stream, the method comprising:
- selecting the text subtitle stream from external source or a recording medium, each text subtitle stream including a style segment defining region style to be applied to at least one region, the style segment further defining at least one set of user control style for each region style, each set of user control style being selectable and configured to change at least one of region presentation properties specified by a corresponding region style; and
- decoding the text subtitle stream using the style segment defining the region style and the at least one set of user control style.
11. A method for reproducing at least one text subtitle stream, the method comprising:
- selecting the text subtitle stream from an external source or a recording medium, the text subtitle stream including a style segment defining region styles and at least one presentation segment, each presentation segment containing at least one region and being linked to at least one of the region styles, the style segment further defining at least one set of user control styles for each region style, each user control style configured to change at least one region presentation property specified by a corresponding region style; and
- decoding the presentation segment using the linked region style and the user control styles.
12. An apparatus for reproducing at least one text subtitle stream, the method comprising:
- decoder configured to decode the text subtitle stream received from an external source, wherein the text subtitle stream including a style segment defining region style to be applied to at least one region, the style segment further defining at least one set of user control style for each region style, each set of user control style being selectable and configured to change at least one of region presentation properties specified by a corresponding region style; and
- controller configured to control operation of the decoder to receive the text subtitle stream from the receiver and decode the text subtitle stream using the style segment defining the region style and the at least one set of user control style.
13. The apparatus of claim 12, wherein each user control style specifies a direction and a magnitude of a change in the at least one of region presentation properties specified by the corresponding region style.
14. The apparatus of claim 12, wherein the region presentation properties include at least one of a region horizontal position, a region vertical position, a text horizontal position, a text vertical position, a line space, and a font size.
15. The apparatus of claim 12, wherein each user control style specifies a direction and a magnitude of a change in at least one of a region horizontal position, a region vertical position, a text horizontal position, a text vertical position, a line space, and a font size, which are specified in the corresponding region style.
16. An apparatus for reproducing at least one text subtitle stream, the method comprising:
- decoder configured to decode the text subtitle stream received from an external source, wherein the text subtitle stream including a style segment defining region styles and at least one presentation segment, each presentation segment containing at least one region and being linked to at least one of the region styles, the style segment further defining user control styles for each region style, each user control style being selectable and configured to change at least one of region presentation properties specified by a corresponding region style; and
- controller configured to control operation of the decoder to receive the text subtitle stream from the receiver and decode each dialog presentation segment using the linked region style and one of user control styles in the text subtitle.
17. An apparatus for reproducing at least one text subtitle stream, the method comprising:
- decoder configured to decode the text subtitle stream selected from an external source, wherein the text subtitle stream including a style segment defining region style to be applied to at least one region, the style segment further defining at least one set of user control style for each region style, each set of user control style being selectable and configured to change at least one of region presentation properties specified by a corresponding region style; and
- controller configured to control operation of the decoder to decode the text subtitle stream using the style segment defining the region style and the at least one set of user control style.
18. The apparatus of claim 17, wherein each user control style specifies a direction and a magnitude of a change in the at least one of region presentation properties specified by the corresponding region style.
19. The apparatus of claim 17, wherein the region presentation properties include at least one of a region horizontal position, a region vertical position, a text horizontal position, a text vertical position, a line space, and a font size.
20. The apparatus of claim 17, wherein each user control style specifies a direction and a magnitude of a change in at least one of a region horizontal position, a region vertical position, a text horizontal position, a text vertical position, a line space, and a font size, which are specified in the corresponding region style.
21. An apparatus for decoding at least one text subtitle stream recorded on a recording medium or received from an external source, the apparatus comprising:
- decoder configured to decode the text subtitle stream selected from an external source, wherein the text subtitle stream including a style segment defining region styles and at least one presentation segment, each presentation segment containing at least one region and being linked to at least one of the region styles, the style segment further defining at least one set of user control styles for each region style, each a set o user control style configured to change at least one of region presentation properties specified by a corresponding region style; and
- controller configured to control operation of the decoder to decode each presentation segment using the linked region style and one of the set of user control styles.
International Classification: H04N 7/00 (20060101);