1. Field of the Invention
The present invention relates to a recording medium, and more particularly, to method and apparatus for reproducing text subtitle stream files. Although the present invention is suitable for a wide scope of applications, it is particularly suitable for efficiently reproducing the text subtitle streams.
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 recording medium, such as a Blu-ray Disc (hereafter referred to as “BD”), is under development for writing and storing high definition video and audio data. Currently, global standard technical specifications of the Blu-ray Disc (BD), which is known to be the next generation technology, are under establishment as a next generation optical recording solution that is able to have a 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), since preferred reproducing methods for reproducing the supplementary data and, most particularly, text subtitle stream files are not completely developed, there are many restrictions in the full-scale development of a Blu-ray Disc (BD) basis optical reproducing apparatus.
Accordingly, the present invention is directed to a method and apparatus for reproducing text subtitle stream files that substantially-obviate one or more problems due to limitations and disadvantages of the related art.
Additional advantages, objects, and features of the invention will be set forth 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 method for reproducing text subtitle streams for a player includes reading a SubPlayItem included in a PlayList recorded on a recording medium, the SubPlayItem designating at least one text subtitle stream, storing a first register value in a first player status register included in the player, the first register value specifying one of the at least one text subtitle stream, reading a second register value contained in a second player status register included in the player, the second register value indicating whether the player is capable of decoding text subtitle streams, and decoding the text subtitle stream specified by the first register value if the second register value indicates the player's decoding capability.
In another aspect of the present invention, an apparatus for reproducing text subtitle streams includes a playback system, which includes a first player status register containing a first register value specifying one of at least one text subtitle stream designated by a SubPlayItem, the SubPlayItem being included in a PlayList recorded on a recording medium, a second player status register containing a second register value indicating whether the playback system is capable of decoding text subtitle streams, and a decoder configured to decode the text subtitle stream specified by the first register if the second register value indicates the decoding capability, and a controller configured to receive one or more operation commands from a user, and to control operation of the playback system according to the operation commands.
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.
The 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 embodiments 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 addition, although the terms used in the present invention are selected from generally known and used terms, some of the terms mentioned in the description of the present invention have been selected by the applicant at his or her discretion, the detailed meanings of which are described in relevant parts of the description herein. Furthermore, it is required that the present invention is understood, not simply by the actual terms used but by the meaning of each term lying within.
In this detailed description, “recording medium” refers to all types of medium that can record data and broadly includes all types of medium regardless of the recording method, such as an optical disc, a magnetic tape, and so on. Hereinafter, for simplicity of the description of the present invention, the optical disc and, more specifically, the “Blu-ray disc (BD)” will be given as an example of the recording medium proposed herein. However, it will be apparent that the spirit or scope of the present invention may be equally applied to other types of recording medium.
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 called 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). These 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” is created and recorded within an optical disc. And, the purpose of the present invention is to provide a method and apparatus for reproducing the recorded text subtitle stream file.
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 (CLIPINF) 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 include mapping information, in which presentation time stamps (PTS) and source packet numbers (SPN) are in a one-to-one correspondence and are mapped by an entry point map (EPM), depending upon the clip type. Using the mapping information, a particular location of a stream file may be determined from a set of 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
Accordingly, a path reproducing the main data by using at least one PlayItem within a PlayList file is called a main path. And, the path reproducing the text subtitle stream file as the supplementary data is called a sub path. More specifically, a main path must be included in a PlayList file, and, when corresponding supplementary data exist, at least one sub path is provided for each supplementary data property. The reproduction of the text subtitle stream file using the main path and the sub path will be described in more, detail in a later process with reference to
The optical recording and/or reproducing apparatus 10 basically includes a pick-up unit 11 for reading control information including data and reproduction control file information recorded within an optical disc, a servo 14 controlling the operations of the pick-up unit 11, a signal processor 13 either recovering the playback signal received from the pick-up unit 11 to a desired signal value, or modulating a signal to be recorded to an optical disc recordable signal and transmitting the modulated signal, and a microcomputer 16 controlling the pickup unit 11, the servo 14, and the signal processor 13. Herein, the pickup unit 11, the servo 14, the signal processor 13, and the microcomputer 16 are collectively referred to as a recording and/or reproducing unit or a drive. Also, the optical recording and/or reproducing apparatus 10 further includes a local storage 15. The local storage 15 downloads data from an external source and stores the downloaded data, thereby enabling the downloaded and stored data to be reproduced with the optical disc.
In addition, as described above, a playback system 17 is a playback (or reproduction) unit for playing-back (or reproducing) the disc along with the data within the local storage. However, the playback system 17 is not necessarily required to be included in the optical recording and/or reproducing apparatus 10 according to the present invention, and so the present invention will not be limited to the above-described structure. The playback system 17 downloads the data existing in an external source and stores the downloaded data into the local storage 15. At the same time, the playback system 17 configures a virtual file system (VFS) for reproducing (or playing-back) the data within the optical disc (hereinafter referred to as an “original data” for simplicity) and the data within the local storage (hereinafter referred to as an “additional data” for simplicity). Then, the playback system 17 creates a virtual package having all of the original data and the corresponding additional data included therein through the virtual file system. Thereafter, the playback system 17 uses the virtual package to reproduce the original data and/or the additional data in accordance with the user's request.
Most particularly, it is apparent that when a text subtitle stream is included as the additional data, the method and apparatus for reproducing the text subtitle stream files according to the present invention may also be applied identically as when reproducing the text subtitle stream file included in the local storage. Accordingly, the playback system 17 includes a plurality of player status registers (PSRs) 171, which will be used when reproducing a loaded disc, and which will be described in detail with reference to
Hereinafter, the method for reproducing the text subtitle stream file according to the present invention will now be described in detail with reference with the accompanying drawings.
As described above,
Accordingly, the playback status registers (i.e., PSR0 to PSR12) are configured with information representing the status of an optical disc currently being reproduced. For example, an Interactive graphics Stream Number- currently being reproduced is, recorded in PSR0, and an Audio Stream number being reproduced is recorded in PSR1. A Presentation graphics and Text subtitle stream Number being reproduced is recorded in PSR2, and an Angle Number being reproduced is recorded in PSR3. A Title Number being reproduced is recorded in PSR4, a Chapter Number being reproduced is recorded in PSR5, a PlayList id being reproduced is recorded in PSR6, and a PlayItem id being reproduced is recorded in PSR7. Presentation time information (e.g., presentation time and Navigation Timer) are recorded in PSR8 and PSR9. And, a button id is selected state is recorded in PSR10, a Menu page id being reproduced is recorded in PSR11, and a User Style id of the text subtitle stream file being reproduced is recorded in PSR12. More specifically, when the optical disc is loaded, the Playback Status Registers (PSR0 to PSR12) are respectively assigned with initial values, which have been pre-decided during an initialization step. The initial values assigned to each PSR may vary in accordance with a selection of presentation stream (or reproduction stream) or presentation method (or reproduction method) made by the user.
Further, the playback setting registers (i.e., PSR13 to PSR31) are configured with information representing the presentation status of an optical recording and/or reproducing apparatus. For example, a Parental level information is recorded in PSR13 for children under the age of 18, and a Player configuration for video representing a display aspect ratio of a video data being reproduced is recorded in PSR14. A Player configuration for audio of a presentable audio format (e.g., whether LPCM, AC-3, and DTS decoding can be performed) us recorded in PSR15, and a Language code of an audio data, a text subtitle stream, and a menu information is each recorded in PSR16 to PSR18, respectively. A Player capability for Text Subtitle is recorded in PSR30, and information indicating a Player Version of the optical recording and/or reproducing apparatus is recorded in PSR31. More specifically, the present invention is related to the presentation (or reproduction) of a text subtitle stream. Hereinafter, among the above-mentioned PSRS, PSR2, PSR17, and PSR30, which are directly related with the presentation of the text subtitle stream, will now be described in detail.
Among the 32 bits of PSR30, 16 bits (e.g. “b15” to “b0”) are used as information indicating the capability of reproducing the text subtitle stream. For example, when all of “b15” to “b0” are equal to ‘0’, the text subtitle stream is incapable of being reproduced. Conversely, when only “b15” is equal to ‘1’, among the 16 bits “b15” to “b0”, and the rest of the bits is equal to ‘0’, the text subtitle stream is capable of being reproduced. The bit column indicating PSR30 is only an example of the present invention. It is apparent that other bit columns may be selected for indicating the “capability” and the “incapability” of reproducing the text subtitle stream according to the present invention.
In the general states, the valid state 82 refers to when the text subtitle stream is reproduced normally, and the invalid state 83 refers to when a PlayList reproduction command is not given or when a valid text subtitle stream does not exist. More specifically, in order to perform a transition between the valid state 82 and the invalid state 81, a status transition is required. The status transition occurs when playback (or reproduction) is requested, or when a playback (or reproduction) condition is changed in accordance to a user command. Moreover, in the temporal states, after determining or verifying a status of a player that is suitable for the corresponding temporal state, a transition to one of the valid state 82 and the invalid state 81 is immediately performed.
For example, in the temporal state, the initialization status 83 refers to when an entire system within the optical recording and/or reproducing apparatus 10 is initialized for the recording/reproducing of the optical disc, once the optical disc is loaded. More specifically, in reproducing the text subtitle stream, the above-described PSR2 is set to be “0x0FFF”, thereby indicating that the text subtitle stream has not yet been selected and is on stand-by as an invalid state 81 in a later process. Additionally, in the temporal state, the procedure when the playback condition is changed 84 refers to a status when a transition of the valid state 82 and the invalid state 81 may occur. For example, in case of the text subtitle stream, when a specific start PlayList playback command is given in the invalid state 81, the playback capability of the text subtitle stream defined in the PlayList is verified in accordance with the value assigned to the above-described PSR30 (i.e., the Player capability for Text subtitle stream). When playback is capable, the status is transited to the valid state 82. Conversely, when playback is incapable, the status is remained as the invalid state 81.
More specifically, when PSR30 is capable of being reproduced (or played-back), the text subtitle stream number designated within PSR2 (i.e., the Presentation graphics and Text subtitle stream Number) is determined, in a later process, to designate any one of the text subtitle streams existing in the optical disc. Thereafter, in order to reproduce the text subtitle stream corresponding to the text subtitle stream number designated to the corresponding PSR2 is transited to be in the valid state 82. Furthermore, in the temporal state, the procedure when a stream change is requested 85 refers to a status when s change occurs from the valid state 82 to a new stream. In other words, as shown in
As described-above, the method and apparatus for reproducing the text subtitle stream files according to the present invention is advantageous in that the text subtitle stream can be reproduced with more efficiency.
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.
Number | Date | Country | Kind |
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10-2005-0016860 | Feb 2005 | KR | national |
This application claims the benefit of the Korean Patent Application No. 10-2005-0016860, filed on Feb. 28, 2005, which is hereby incorporated by reference as if fully set forth herein. This application claims the benefit of the U.S. Provisional Application No. unkown, in the name of inventors Kang Soo SEO, Byung Jin JIM, Jea Yong YOO, and Seung Hoon LEE, entitled “PLAYBACK PROCEDURE BASED ON PLAYER STATUS REGISTER (PSRs)”, which is hereby incorporated by reference as if fully set forth herein.
Number | Date | Country | |
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60550331 | Mar 2004 | US |