HK1099451B - Storage medium, reproducing apparatus and method for reproducing from the same - Google Patents

Description

Storage medium, reproducing apparatus and reproducing method thereof

This application is a divisional application of a patent application having an application date of 14/1/2005, an application number of 200510002079.2, entitled "storage medium, and reproducing apparatus and reproducing method therefor".

Technical Field

The present invention relates to reproduction of multimedia images, and more particularly, to a storage medium storing an interactive graphic stream displayed in response to a user command, and a reproducing apparatus and method for reproduction therefrom.

Background

To reproduce a multimedia image, audio-visual (AV) data of the multimedia image, navigation data controlling reproduction of the AV data, and system data including command information related to a title of the AV data, which is initially reproduced when the storage medium is inserted into a reproducing apparatus, are recorded in the storage medium. Other data may also be recorded in the storage medium. In particular, AV data is recorded in a storage medium as a main stream by multiplexing video, audio, subtitles, and menus.

Fig. 1 is a block diagram of general AV data recorded in a storage medium.

Referring to fig. 1, in a storage medium storing multimedia images, a video stream 102, an audio stream 104, a presentation graphic stream 106 for providing subtitles, and an interactive graphic stream 108 for providing a menu screen are multiplexed and recorded as a main stream. Hereinafter, the multiplexed main stream is referred to as AV data 110.

Fig. 2 is a block diagram of a general reproducing apparatus for reproducing AV data from a storage medium 200 in which the AV data 110 is recorded.

Referring to fig. 2, the reproducing apparatus for reproducing multimedia images reads navigation data as described above and obtains control information required to reproduce AV data 110. For example, the control information includes an encoding type of the AV data 110, a bit rate, information indicating an area in which the AV data 110 is recorded, and a type of data included in the AV data 110. The reading unit 210, the demultiplexer 220, the video decoder 230, the display decoder 240, the interactive graphic decoder 250, and the audio decoder 260 are controlled by referring to the control information, respectively.

In detail, referring to fig. 1 and 2 together, the reading unit 210 reads the multiplexed AV data 110 from the storage medium 200 by using information indicating an area in which the AV data 110 is recorded, and transmits the multiplexed AV data 110 to the demultiplexer 220. The demultiplexer 220 divides the received AV data 110 into a video stream 102, an audio stream 104, a presentation graphic stream 106, and an interactive graphic stream 108, and transmits the divided streams 102 to 108 to the decoders 230 to 260, respectively. Each stream transmitted to the respective decoders is decoded according to a corresponding data type and is ready to be displayed on a screen at a specific time. The decoded video stream 102, the display graphics stream 106, and/or the interactive graphics stream 108 are overlaid as a single image using the mixer 270. Finally, an image selected based on the output state set by the user is displayed on the screen. For example, the output state may be controlled based on a user's selection, such as a subtitle on/off state and a mute state.

Specifically, the interactive graphic decoder 250 receives the interactive graphic stream 108 from the storage medium 200, decodes the interactive graphic stream 108, and outputs a menu screen including buttons on a screen at a designated time. The user's selection may be input by the user selecting a particular button on the output menu screen. That is, user interactive functionality may be provided.

However, when reproducing multimedia, such as a movie, the conventional reproducing apparatus unconditionally outputs a menu screen at a designated time even if the user does not want to view the menu. When watching a movie, it may be inconvenient for the user if an undesired menu screen is displayed.

Disclosure of Invention

Embodiments of the present invention provide a storage medium storing an on-demand interactive graphic stream activated in response to a user command by extending an interactive graphic stream function to support a user interactive operation, and a reproducing apparatus and method for reproducing from the storage medium.

According to an aspect of the present invention, there is provided a storage medium including video data and graphic data for displaying a menu screen overlaid on an image displayed on the basis of the video data. The graphic data includes first graphic data displayed on a screen when an activation command is generated by a user.

The graphic data may further include second graphic data displayed on the screen at a designated time.

The first and second graphic data may have the same or similar structure including fields for distinguishing each other.

The first and second graphic data may have a graphics _ segment structure including a segment _ type field defining a first and second graphic data type value, respectively.

The first and second graphic data may have interactive _ graphic _ segment structures including type fields for distinguishing each other.

The first graphic data may have an on _ command _ interactive _ graphic structure different from that of the second graphic data. The on _ command _ interactive _ graphic structure may include information on an initial menu page indicating that the first graphic data is decoded and ready to be displayed and information on at least one menu page displayed when an activation command is generated by a user. Each menu page may include information for displaying at least one button and information about a command executed when a user selects the button.

The first graphic data may be multiplexed with the video data and recorded in a single stream, or the first graphic data and the second graphic data may be multiplexed with the video data and recorded in a single stream.

The first graphic data and the second graphic data may be multiplexed together with the video data and recorded in a single stream, and the object data, which is used by the first graphic data and indicates an image of a menu screen, may be included in separate streams and recorded.

According to another aspect of the present invention, there is provided a reproducing apparatus for reproducing video data and graphic data for displaying a menu overlaid on an image displayed on the basis of the video data from a storage medium, comprising: a video decoder for decoding video data; and a graphic decoder for decoding the graphic data. The graphics decoder decodes first graphics data that is displayed when the graphics data is of a particular type and an activation command is received. When the graphic data is not of the first type, the second graphic data is displayed at the designated time.

The apparatus may further include: a mixer for overlapping the decoded video data and the decoded graphic data; and an interface for transmitting the user command to the graphic decoder.

According to another aspect of the present invention, there is provided a reproducing method for reproducing a storage medium storing video data and graphic data for displaying a menu screen overlaid on an image displayed on the basis of the video data. The method comprises the following steps: decoding the graphic data, outputting the decoded graphic data when an activation command is generated by a user based on the decoded graphic data, or outputting the decoded graphic data at a designated time.

According to another aspect of the present invention, there is provided a method for reproducing an interactive graphic stream from a storage medium, the method including: reading an interactive graphics stream from a storage medium; decoding the read interactive graphics stream; determining the type of the read interactive graphics stream; and mixing the decoded interactive graphics stream with video data and performing one of the following operations: the mixed data is displayed at a designated time when the decoded interactive graphic stream is a normal interactive graphic stream, and the mixed data is displayed when an activation command is received when the decoded interactive graphic stream is an on-demand interactive graphic stream.

According to another aspect of the present invention, there is provided an interactive graphic decoder, including: a stream graphic processor for decoding the received interactive graphic stream and transmitting button image object data and button structure information after decoding; a coded data buffer for temporarily storing the interactive graphics stream and then transmitting the interactive graphics stream to the stream graphics processor; an object buffer for receiving button image object data; a composition buffer for receiving button configuration information; and a graphic controller for creating an image to be displayed by using the data stored in the object buffer and the composition buffer, and transmitting the created image from the object buffer to the graphic plane.

According to another aspect of the present invention, there is provided a reproducing method for reproducing video data and graphic data from a storage medium, the method including: decoding the video data; decoding graphic data to display a menu screen, wherein the graphic data includes: at least one display group including a composition segment, an end segment, and a definition segment including object data, and the composition segment including mode information of the display group.

Additional and/or other aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

These and/or other aspects and advantages of the present invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a diagram of conventional AV data recorded in a storage medium;

fig. 2 is a diagram of a conventional reproducing apparatus for reproducing a storage medium in which AV data is recorded;

FIG. 3 illustrates a structure of an interactive graphics stream according to an embodiment of the present invention;

FIG. 4 illustrates an operation when a general interactive graphic stream is reproduced;

FIGS. 5A and 5B illustrate operations when an on-demand interactive graphic stream is reproduced according to an embodiment of the present invention;

FIGS. 6A through 6C illustrate a method of distinguishing an on-demand interactive graphics stream from a general interactive graphics stream according to an embodiment of the present invention;

FIG. 7 illustrates a method of distinguishing an on-demand interactive graphics stream from a generic interactive graphics stream according to another embodiment of the present invention;

FIG. 8 illustrates a method of distinguishing an on-demand interactive graphics stream from a generic interactive graphics stream according to another embodiment of the present invention;

FIG. 9 is a block diagram of a reproducing apparatus for reproducing an on-demand interactive graphic stream according to an embodiment of the present invention;

FIG. 10 is a block diagram of a reproducing apparatus for reproducing an on-demand interactive graphic stream according to another embodiment of the present invention;

11A-11D illustrate interactive graphic streams included in AV data according to an embodiment of the present invention;

fig. 12 illustrates a structure of a player status register recording information on an interactive graphics stream according to an embodiment of the present invention;

fig. 13 illustrates a structure of a player status register recording information on an interactive graphics stream according to another embodiment of the present invention;

FIG. 14 illustrates a process for processing commands for activating an on-demand interactive graphics stream generated by a user;

fig. 15A and 15B show display states of values of a disp-flag according to the structures of the player status registers shown in fig. 12 and 13, respectively;

FIG. 16 illustrates a system menu of a reproducing apparatus in which menu items for turning on/off an output of an on-demand interactive graphic stream are defined;

FIG. 17 is a schematic diagram of a remote control device including buttons for turning on/off the output of an on-demand interactive graphics stream;

fig. 18 is a flowchart illustrating a method of reproducing a storage medium on which an interactive graphic stream is recorded according to an embodiment of the present invention; and

fig. 19 is a detailed flowchart illustrating a method of reproducing a storage medium on which the on-demand interactive graphics stream shown in fig. 18 is recorded.

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.

A general interactive graphic stream as used in this specification refers to a data stream that provides a menu screen at a specified time. In addition, an on-demand (on-demand) interactive graphic stream used in the present specification refers to a data stream providing a menu screen that is displayed only when a user desires.

Fig. 3 illustrates a structure of an interactive graphics stream according to an embodiment of the present invention.

Referring to fig. 3, the interactive graphics stream is divided into periodic (epoch) units according to how the decoder operates. Information for reproducing a button on a menu screen including a plurality of buttons is called an interactive graphic object. All the interactive graphic objects included in a cycle are decoded and stored in an object buffer of an interactive graphic decoder, which will be described later, and the stored objects are maintained unless data of a subsequent cycle is input. Therefore, in one cycle, the interactive graphic object does not have to be decoded every time it is used, and the interactive graphic object that has been decoded and stored can be reused. However, when a subsequent cycle starts after completion of one cycle, all buffers of the decoder are reset and all stored data disappears. In addition, the amount of time after which the buffer of the decoder is reset is defined as a specific time.

As shown in fig. 3, a display group is defined as an output unit of an interactive graphic object. The display group represents a group of interactive graphic objects displayed on a single screen, and one cycle may include at least one display group. There are three types of display groups. The first type is an Epoch Start (ES) display group indicating the start of an epoch, and includes all data for outputting interactive graphics, such as interactive graphic structure information required to construct interactive graphics and object data for button images. The second type is an Acquisition Point (AP) display group that can exist after the ES display group, and includes all information for constructing an interactive graphic to prepare for a situation such as a random search by a user. The third type is a normal state (NC) display set of data that must be changed among interactive graphics included in a previous display set, i.e., data to be updated only. As shown in fig. 3, one cycle may include a plurality of display sets. The ES display group exists at the beginning of the cycle, and the AP and NC display groups are located at subsequent positions. The ES display set is necessary for each cycle, but the AP and NC display sets are optional.

Each display group includes a composition segment storing structure information of the interactive graphics stream, a plurality of definition segments each recording object data of a real image such as a button displayed on a screen, and an end segment representing an end of the display group. The composition section includes output completion time information, button structure information, and operation information indicating how the reproducing apparatus responds to a user operation. The composition segment may be implemented with an Interactive Composition Segment (ICS) data structure. The definition segment includes an Object Definition Segment (ODS) containing object data having image information of a button and a Palette Definition Segment (PDS) containing color information applicable to the ODS.

Each clip in a single presentation group is recorded in a Packetized Elementary Stream (PES), which is a packet unit of an MPEG-2 Transport Stream (TS). The pertinent display group is decoded at a decoding time indicated by a Decoding Time Stamp (DTS) included in the PES, and is displayed on the screen at a display time indicated by a Presentation Time Stamp (PTS). In addition, the output completion time when the output of the relevant display group is completed is determined by the composition _ time _ out _ pts field value recorded in the ICS indicating the data structure of the composition clip.

Accordingly, the interactive graphics stream is displayed on the screen at the specified time indicated by the PTS, a user command is received, in response to which an operation is performed, and the interactive graphics stream disappears from the screen at the specified output completion time indicated by the composition _ time _ out _ PTS. However, if the interactive graphic stream is output only by using the designated time, the menu screen is unconditionally output at the designated time even if the user does not want the output thereof. That is, the menu screen can be activated not only when the user wants its activation, but also at a time other than when the user wants its activation.

Therefore, according to an embodiment of the present invention, an on-demand interactive graphic stream activated by a user command is defined to perform a user interactive operation by extending the function of the interactive graphic stream. In order to distinguish from the on-demand interactive graphics stream defined in the present invention, the interactive graphics stream output at a given time is referred to as a normal interactive graphics stream.

The normal interactive graphic stream is displayed on the screen at a designated time and disappears at a designated time thereafter. On the other hand, only when an activation command is generated by the user after all data is decoded and ready to be output, the on-demand interactive graphic stream is displayed on the screen and a specified operation is performed in response to an input from the user. That is, as in the general interactive graphic stream, in the on-demand interactive graphic stream, an interactive graphic object, e.g., a button, may be first displayed at a time specified by the PTS. However, in an on-demand interactive graphics stream, buttons are not displayed on the screen unless the user enters a command to do so.

In the normal interactive graphics stream, the composition _ time _ out _ pts represents the time when the button is no longer displayed on the screen. However, in the on-demand interactive graphics stream, the composition _ time _ out _ pts represents a time when data related to a button is deleted from a buffer of a decoder. That is, even though the button activation command is generated by the user after the output completion time, the activation command from the user is ignored since the on-demand interactive graphic stream to be activated no longer exists.

Fig. 4, 5A and 5B are diagrams illustrating an operational difference between a general interactive graphic stream (fig. 4) and an on-demand interactive graphic stream (fig. 5A and 5B) according to an embodiment of the present invention.

Fig. 4 illustrates an operation when a general interactive graphic stream is reproduced. Referring to fig. 4, a general interactive graphic stream is multiplexed in AV data. Each decoded general interactive graphic stream is displayed on a screen according to the PTS included in the ICS of the ES display group. Here, the user can navigate or select buttons displayed on the screen. According to the user command, the operation assigned to the button is performed.

For example, when navigating a button, the state of the button is changed from a selected state to an unselected state, an output image of the button is changed to be suitable for the unselected state, and when a user selects a specific button, an operation according to a navigation command assigned to the specific button is performed. In addition, when the command assigned to the specific button is a command to move to another location of the AV data, the specific button disappears from the screen even if the output completion time (composition _ time _ out _ pts) of the general interactive graphics stream has not yet arrived, and the AV data indicated by the move command is displayed on the screen. On the other hand, when the command assigned to the specific button is not a command to move to another position of the AV data, the command defined to the specific button is executed, the output state of each button is maintained until the output completion time (composition _ time _ out _ pts) is reached, and the specific button disappears from the screen when the output completion time (composition _ time _ out _ pts) is reached. That is, the normal interactive graphic stream is displayed on the screen at a designated time, and disappears from the screen when a designated output completion time is reached.

Fig. 5A and 5B illustrate operations when an on-demand interactive graphic stream is reproduced according to an embodiment of the present invention.

Referring to fig. 5A, an on-demand interactive graphic stream is multiplexed in AV data. When the on-demand interactive graphics stream is decoded, the on-demand interactive graphics stream is ready to be activated. Even if the on-demand interactive graphics stream is ready to be activated, the relevant buttons are displayed on the screen only when a user command is generated and in this case can be received. When the composition _ time _ out _ pts reaches the output completion time, the relevant button displayed on the screen disappears from the screen. In addition, when the output completion time is reached by setting the period as the output completion time, all decoded data in the buffer of the decoder disappears. Therefore, the activation command of the user received after the output completion time is ignored.

Referring to FIG. 5B, like the general interactive graphics stream shown in FIG. 4, a period may be defined as an end before it reaches the ICS of a subsequent ES display group. In this case, since all the pertinent data in the buffer of the decoder is deleted when the ICS of the subsequent ES display group is reached, the pertinent data does not have to be deleted from the decoder even if the composition _ time _ out _ pts has been reached. However, even if the activation command of the menu is generated by the user after the output completion time is reached, the selected button is not reproduced by recognizing that the effective interactive display duration has ended. That is, the activation command of the user received after the output completion time is ignored.

As described above, the on-demand interactive graphic stream and the general interactive graphic stream have the same or similar data structure. However, the difference between the two streams is that the display of the on-screen button is determined in the on-demand interactive graphic stream according to the user's activation command and in the general interactive graphic stream according to the designated time. That is, if only information for distinguishing between two types of interactive graphic streams is added, the same data structure may be used to implement the two types of interactive graphic streams.

Another method of distinguishing an on-demand interactive graphic stream from a general interactive graphic stream is as follows:

the first method comprises the following steps: method for distinguishing two streams by using segment _ type field of ICS

The second method comprises the following steps: method for distinguishing two streams by adding ICS _ type field of ICS

The third method comprises the following steps: a method for distinguishing two streams by defining an On _ demand _ ICS structure as a new structure of an On-demand interactive graphics stream.

Fig. 6A to 6C illustrate a method (first method) of distinguishing an on-demand interactive graphic stream from a general interactive graphic stream according to an embodiment of the present invention.

Referring to fig. 6A and 6B, the graphics segment structure includes a segment _ descriptor602 including a segment _ type field 604 representing a segment type. In fig. 6C, a segment type that the segment _ type field 604 can represent is defined. In the first method, the segment _ type field 604 can be defined such that the Normal interactive graphics stream type (Normal _ ICS)606 has a value of 0x18 and the On-demand interactive graphics stream type (On _ demand _ ICS)607 has a value of 0x 19. That is, when two types of interactive graphic streams have the same structure, the first method distinguishes the two types of interactive graphic streams using the segment _ type field 604.

Fig. 7 illustrates a method (second method) of distinguishing an on-demand interactive graphic stream from a general interactive graphic stream according to another embodiment of the present invention.

Referring to fig. 7, the on-demand interactive graphic stream and the general interactive graphic stream have the same structure (interactive _ composition _ segment), and in the second method, two types of interactive graphic streams are distinguished by using an ICS _ type field 702. That is, the ICS _ type field is defined such that if the value of ICS _ type is 0, ICS _ type represents a general interactive graphics stream, and if the value of ICS _ type is 1, ICS _ type represents an on-demand interactive graphics stream.

Fig. 8 illustrates a method (third method) of distinguishing an on-demand interactive graphic stream from a general interactive graphic stream according to another embodiment of the present invention.

Referring to FIG. 8, a newly defined On _ demand _ ICS structure is shown. Unlike the first and second methods in which the same structure is used, in the third method, a new structure of the on-demand interactive graphics stream is defined.

Unlike the structure of a general interactive graphics stream, the On _ demand _ ICS structure, a new structure of an On-demand interactive graphics stream defines pages constructed by operations, such as an initial menu page including an initial button informing a user that the On-demand interactive graphics stream is decoded and ready to be activated by the user and pages including buttons to be displayed after the On-demand interactive graphics stream is activated by the user, i.e., first to nth menu pages. Each menu page to be displayed may include reproduction information of at least one button to be displayed and command information indicating what operation is to be performed if the button is selected.

The structure of a reproducing apparatus supporting an on-demand interactive graphics stream according to an embodiment of the present invention will be described on the basis of the on-demand interactive graphics stream according to an embodiment of the present invention described above.

Fig. 9 and 10 are block diagrams of a reproducing apparatus for reproducing an on-demand interactive graphic stream according to an embodiment of the present invention.

Referring to fig. 9, an interactive graphic decoder 910 of a reproducing apparatus according to an embodiment of the present invention is shown. AV data read from a storage medium is input to a Packet Identifier (PID) filter 902, and only an interactive graphic stream is selectively transmitted to a transport buffer 904 and decoded by an interactive graphic decoder 910.

In the interactive graphics decoder 910, an interactive graphics stream is temporarily stored in the encoded data buffer 912 and then transmitted to the stream graphics processor 914. After the interactive graphics stream is decoded by the stream graphics processor 914, the button image object data is sent to an object buffer 916 and the button structure information is sent to a composition buffer 918. The graphic controller 920 creates an output image with respect to the received object data with reference to the related configuration information and transmits the created image to the graphic plane 930. That is, at a time identified by the PTS, the output start time of the interactive graphics stream, the graphics controller 920 determines an image to be displayed on the screen, and transmits the determined image from the object buffer 916 to the graphics plane 930. The transmitted image is output with reference to a color lookup table (CLUT)932 according to color information included in the related configuration information. In addition, in response to a user command according to the movement or selection of the button, the graphic controller 920 may change the state of the button and adapt the result to the screen output.

In particular, fig. 9 shows a block diagram of the thus-configured reproducing apparatus in which the general interactive graphic stream and the on-demand interactive graphic stream use the same buffer memory. Since the two types of interactive graphics streams use the same buffer of the decoder 910 as shown in fig. 9, only one of the normal interactive graphics stream and the on-demand interactive graphics stream may exist in the buffer of the decoder 910 at a given time. That is, only one type of interactive graphics stream may be processed at a time.

Fig. 10 is a block diagram of a reproducing apparatus for reproducing an on-demand interactive graphic stream according to another embodiment of the present invention.

Referring to fig. 10, the thus configured reproducing apparatus is shown in which a general interactive graphic stream and an on-demand interactive graphic stream are stored in separate buffer memories. That is, the normal interactive graphics stream is stored in the normal ICS memory area 1010, and the on-demand interactive graphics stream is stored in the on-demand ICS memory area 1020. Thus, both types of interactive graphics streams may exist in the buffer at the same time. In this case, when the general interactive graphics stream is input in a case where the on-demand interactive graphics stream exists in the buffer, or when the on-demand interactive graphics stream is input in a case where the general interactive graphics stream exists in the buffer, the buffer memory of the decoder does not have to be reset. However, when the two types of interactive graphics streams are simultaneously displayed on the screen, which object the user operation relates to may not be clear, and there may be a problem in adapting the color information to the screen structure. Accordingly, although not shown in fig. 10, the reproducing apparatus may further include a control unit selecting a general interactive graphic stream or an on-demand interactive graphic stream to be output, and respective cut blocks for the interactive graphic streams.

Fig. 11 illustrates an interactive graphic stream included in AV data according to an embodiment of the present invention.

Referring to fig. 11, fig. 11A shows a case where only an on-demand interactive graphic stream is recorded in a single AV data. Fig. 11B shows a case where only a general interactive graphic stream is recorded in a single AV data. Fig. 11C shows a case where two types of interactive graphic streams are mixed and recorded in a single AV data. Fig. 11D shows a case where two types of interactive graphic streams are mixed and recorded in a single AV data, and an on-demand interactive graphic stream is separated from other AV data and recorded. Specifically, referring to fig. 11D, when AV data is read from the beginning, on-demand ICS data recorded in the beginning of the AV data is referred to. However, when AV data is read from an intermediate position, since only structure information is recorded in the AV data and object data of an actual button image is separately recorded, a button is output by using the separately recorded object data with reference to the structure information recorded in the AV data. In this case, unnecessary data redundancy can be prevented by separately recording the object data.

A process of outputting an on-demand interactive graphic stream onto a screen according to a user's activation command will be described based on the data structure of the on-demand interactive graphic stream and the structure of the reproducing apparatus described above.

Fig. 12 and 13 illustrate the structure of a player status register for recording information on an interactive graphics stream according to an embodiment of the present invention.

Referring to fig. 12, in a Player Status Register (PSR), the number of an interactive graphics stream currently being reproduced or an interactive graphics stream to be reproduced later is recorded. In fig. 12, the number is recorded in bits 0 to 7 of the PSR 0. Therefore, even when the reproduction of the multimedia image is temporarily stopped and restarted, the interactive graphics stream that was being reproduced previously can be reproduced again by referring to PSR 0.

In a reproducing apparatus supporting both a general interactive graphic stream and an on-demand interactive graphic stream, it must be determined whether a stream number recorded in PSR0 represents a number of the general interactive graphic stream or a number of the on-demand interactive graphic stream. Therefore, the reproducing apparatus according to an embodiment of the present invention includes an ICS _ use flag for determining whether the interactive graphics stream number recorded in PSR0 represents a number of a general interactive graphics stream or a number of an on-demand interactive graphics stream. In FIG. 12, the ICS _ usage flag is recorded in bit 30 of PSR 0. That is, if the currently reproduced stream is an on-demand interactive graphics stream, the ICS _ usage flag is set to 1, and if the currently reproduced stream is a normal interactive graphics stream, the ICS _ usage flag is set to 0.

In addition, in the on-demand interactive graphics stream, a disp _ flag is defined to indicate whether the stream is to be displayed on a screen. In fig. 12, a disp _ flag is recorded in bit 31 of PSR 0. If the disp _ flag is set to 1, when the on-demand interactive graphics stream is ready to be activated, the reproducing apparatus displays an initial menu page on the screen to inform the user that the on-demand interactive graphics stream is ready to be activated. If the disp _ flag is set to 0, the reproducing apparatus does not display the interactive graphics on the screen.

On the other hand, when the disp _ flag is set to 0 and the on-demand interactive graphics stream is ready to be activated, that is, when the on-demand interactive graphics stream is ready to be activated and the on-demand interactive graphics stream will not be displayed on the screen, there are two methods of processing the on-demand interactive graphics stream. In the first method, the reproduction apparatus is configured such that: the on-demand interactive graphics stream is activated when an activation command is generated by a user. In the second method, the reproduction apparatus is configured such that: the on-demand interactive graphics stream is not activated and the user's commands are ignored when generated by the user.

Fig. 13 illustrates a structure of a player status register recording information on an interactive graphics stream according to another embodiment of the present invention. Referring to fig. 13, a reproducing apparatus configured to record two types of interactive graphic streams in separate PSRs is shown. That is, a case where information on a general interactive graphics stream is recorded in the PSR0 and information on an on-demand interactive graphics stream is recorded in the PSR11 is shown.

If the ICS _ type field represents a normal interactive graphics stream, information on the normal interactive graphics stream is recorded in the PSR0, and if the ICS _ type field represents an on-demand interactive graphics stream, information on the on-demand interactive graphics stream is separately recorded in the PSR 11. Therefore, unlike the structure shown in fig. 12, an ICS _ usage flag for determining the ICS type of the interactive graphics stream is not required. However, in the PSR11, a disp _ flag indicating whether an initial menu page for notifying a user that the on-demand interactive graphics stream is ready to be activated is displayed on the screen is required, and the operation of the disp _ flag is the same as that of fig. 12. In fig. 13, a disp _ flag is recorded in bit 31 of the PSR 11.

FIG. 14 illustrates a process for processing a command generated by a user to activate an on-demand interactive graphics stream.

Referring to fig. 14, when an activation command is generated by a user, a reproducing apparatus determines whether an on-demand interactive graphic stream is ready to be activated in an interactive graphic decoder, and if the on-demand interactive graphic stream is ready to be activated, the on-demand interactive graphic stream is displayed on a screen, a focus is set to receive a user command, and a button selection from the user is ready to be received. If the on-demand interactive graphic stream is not ready to be activated, an activation command from the user is ignored, or a message informing the user that the on-demand interactive graphic stream to be output does not exist is displayed on the screen.

Fig. 15A and 15B show display states of values of a disp _ flag according to the structures of the player status registers shown in fig. 12 and 13, respectively.

Referring to fig. 15A, when the disp _ flag is set to 1, if the on-demand interactive graphics stream is decoded and is ready to be activated, an initial menu page is displayed on the screen to inform the user that the on-demand interactive graphics stream is ready to be activated. If an activation command for the on-demand interactive graphics stream is generated by a user, a first menu page is displayed on the screen.

Referring to fig. 15B, when the disp _ flag is set to 0, the initial menu page is not displayed on the screen even though the on-demand interactive graphics stream is decoded and is ready to be activated. However, when the activation command for the on-demand interactive graphics stream is generated by the user, the reproducing apparatus may be configured such that the activation command is ignored or the first menu page is displayed on the screen.

Fig. 16 illustrates a system menu of a reproducing apparatus in which menu items for turning on/off an output of an on-demand interactive graphic stream are defined. If the user sets the on-demand ICS display item to ON, a status register storing information on the on-demand interactive graphics stream, for example, the disp _ flag of the PSR0 or the PSR11 described above, is set to 1. On the other hand, if the user sets the on-demand ICS display item to OFF, the reproducing apparatus sets the disp _ flag of the status register to 0. That is, the disp _ flag may be changed by using a user interface called a system menu.

FIG. 17 is a schematic diagram of a remote control device including buttons for turning on/off the output of an on-demand interactive graphics stream. The user can set the disp _ flag of the status register to 0 or 1 by pushing the relevant button.

Based on the above-described data structure of the on-demand interactive graphics stream and the structure of the reproducing apparatus, a reproducing method according to an embodiment of the present invention will now be described.

Fig. 18 and 19 are flowcharts illustrating a method of reproducing a storage medium on which an interactive graphic stream is recorded according to an embodiment of the present invention.

Referring to fig. 18, in operation 1802, an interactive graphic stream is read from a storage medium storing a general interactive graphic stream and/or an on-demand interactive graphic stream. In operation 1804, the read interactive graphics stream is decoded. In operation 1806, the type of the decoded interactive graphic stream is checked. If the decoded interactive graphic stream is a general interactive graphic stream, the decoded interactive graphic stream is mixed with video data and displayed on a screen at a designated time in operation 1808. If the decoded interactive graphic stream is an on-demand interactive graphic stream, the decoded interactive graphic stream is mixed with video data and is displayed on a screen only when an activation command is generated by a user in operation 1810.

Fig. 19 is a detailed flowchart illustrating a process of reproducing the on-demand interactive graphic stream illustrated in fig. 18.

Referring to fig. 19, if the decoded interactive graphics stream is an on-demand interactive graphics stream, a disp _ flag indicating whether the on-demand interactive graphics stream is to be displayed on a screen is read from a player status register in operation 1902. If the value of the disp _ flag is 1 in operation 1904, the user is informed that an initial menu page, in which the on-demand interactive graphics stream is ready to be activated, is displayed on the screen in operation 1906. If the user inputs an activation command while the output initial menu page is displayed in operation 1908, a menu page according to the user command is displayed on the screen in operation 1910.

On the other hand, if the value of the disp _ flag is 0 in operation 1904, nothing is displayed on the screen, and even if an activation command is generated by the user in operation 1920, the activation command is ignored in operation 1922. Although not shown in fig. 19, if the value of the disp _ flag is 0, nothing is displayed on the screen, and if an activation command is generated by a user by using a user interface, such as a remote control device, an initial menu page is displayed on the screen.

By using the on-demand interactive graphic stream according to the described embodiments of the present invention, the on-demand interactive graphic stream may be controlled such that it is displayed on the screen at a designated time and disappears from the screen at the designated time, or is displayed on the screen only when a user generates a command.

According to the described embodiments of the present invention, interactive graphics, such as buttons, may be controlled by using an on-demand interactive graphics stream, such that the buttons are displayed on a screen when a user generates a command.

In addition, an interactive graphic stream dedicated to a relevant area may be constructed by constructing different on-demand interactive graphic streams for certain areas or chapters (chapters) of AV data. For example, instead of the buttons for performing the fixed function, information about actors/actresses existing in some areas included in the multimedia image, attributes, and a photographing position may be provided to the user.

In addition, the number of buttons on the remote control device may be reduced by configuring the functions of the buttons corresponding to the remote control device using a menu-driven method using an on-demand interactive graphics stream.

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 (6)

1. A reproducing method for reproducing video data and graphic data from a storage medium, the method comprising:

decoding the video data;

the graphic data is decoded to display a menu screen,

wherein the graphic data includes: at least one display group including a composition segment, an end segment, and a definition segment including object data, and the composition segment including mode information of the display group.

2. The reproducing method of claim 1, wherein the mode information indicates whether a mode of the display group is a first mode or a second mode, wherein the first mode is activated by a user's command and the second mode is activated at a designated time.

3. The reproducing method of claim 2, wherein the first graphic data and the second graphic data have the same or similar structure including a field for distinguishing the first graphic data and the second graphic data.

4. The reproducing method of claim 3, wherein the first graphic data and the second graphic data have a graphics _ segment structure including a segment _ type field defining a type of the first graphic data and a type of the second graphic data, respectively.

5. The reproducing method of claim 3, wherein the first graphic data and the second graphic data have an interactive _ graphic _ segment structure including a type field for distinguishing the first graphic data and the second graphic data.

6. The reproducing method of claim 5, wherein the type field is defined such that: when the value of the type field is 0, the second graphic data is indicated, and when the value of the type field is 1, the first graphic data is indicated.