Information storage medium storing graphic data and apparatus and method of processing the graphic data

Abstract

An information storage medium including graphic data and presentation information, and an apparatus and method of processing the graphic data are provided. The information storage medium includes the graphic data, page composition information which defines page composition of the graphic data, and the presentation information indicating when graphic screen data, which is composed with reference to the page composition information of the graphic data, is output to a display screen. Therefore, a graphic object is reusable in graphic data processing, and accordingly, a time taken to process the graphic data is reducible and memory area may be saved.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This ends, finishes, since an ideal decoding time of the graphic data in the decoder 232 is 0. That is, a time when the ODS 122a through 122n is output from the coded data buffer 231 is equal to a time when the ODS 122a through 122n is stored in the first buffer 233. The PTS information of the ODS 122a through 122n indicates not only the time when the ODS 122a through 122n is output from the coded data buffer 231, but also the time when the ODS 122a through 122n is stored in the first buffer 233 after being decoded. However, since it actually takes some time for the decoder 232 to decode the ODS 122a through 122n, the PTS information of two ODSs, for example, ODS 122a and 122b, have a predetermined time interval therebetween in consideration of a time required for the decoder 232 to decode a previous object.

The decoder 232 decodes the input subtitle graphic data and input navigation graphic data. After the input subtitle and input navigation graphic data are decoded, the decoded PCS 121 is output to the page composition buffer 235 and the decoded ODS 122a through 122n is output to the first buffer 233. Theoretically, a time taken to decode the input data in the decoder 232 is 0. Thus, the decoding operation is called an instant decoding operation.

The page composition buffer 235 stores the PCS 121 which is decoded and output from the decoder 232.

The first buffer 233 stores the ODS 122a through 122n, which is decoded in the decoder 232, according to object identifier object_id of the ODS 122a through 122n. Since the decoded object data is stored in the first buffer 233, one object is reusable several times before the first buffer 233 is completely reset.

The second buffer 234 stores data right before graphic screen data of a screen, which is composed of graphic data objects necessary to display the subtitle graphic data and the navigation graphic data on the display device, is output. The data stored in the second buffer 234 is output to the display device according to the PTS information of the PCS 121 having page composition information of a pertinent page.

The image controller 236 controls, with reference to object identifiers (i.e., object_id), objects to be transmitted from the first buffer 233 to the second buffer 234 and to be displayed on one page. That is, the image controller 236 controls the first buffer 233 to select the graphic data object necessary to compose the pertinent page (i.e. screen), based on the page composition information of the PCS data output from the page composition buffer 235, and to transmit selected graphic data object from the first buffer 233 to the second buffer 234. The image controller 236 transmits the page composition information to the second buffer 234 to compose the display screen. Further, when the image controller 236 receives a user command from a user, the image controller 236 controls the above elements to select the subtitle graphic data and the navigation graphic data having a different PID and composes a display screen.

FIG. 3 is a diagram illustrating a third embodiment of the present invention of graphic data.

An operation of processing the graphic data having display sets 120a through 120n in a graphic data processing apparatus 230 and displaying the processed graphic data on a display screen will be explained in detail with reference to FIG. 3.

Referring to FIG. 3, subtitle graphic data and navigation graphic data have four display sets 305 through 320, 325 through 330, 335 through 345, and 350 through 360. As an MPEG-2 TS including a plurality of display sets passes through the decoder 232, the subtitle graphic data and the navigation graphic data included in the ODS 122a through 122n is stored in the first buffer 233 and the page composition information contained in the PCS 121 is stored in the page composition buffer 235. Further, both the graphic data and the page composition information are transmitted to the second buffer 234 based on respective PTS information. The operation will be explained below. A header of each display set is not shown in FIG. 3 for convenience of description.

FIG. 4A is a diagram illustrating a state in which a first display set 305 through 320 having a PCS 305 with a page_id=1 is stored in buffers.

Graphic data of an ODS 310 with an object_id=1 and graphic data of an ODS 315 with the object_id=2 are stored in the first buffer 233 at a time indicated by the PTS information included in the ODSs 310 and 315. At this time, no data is stored in the page composition buffer 235. In general, an instance where all object data stored in the first buffer 233 is no longer used and a new display set is input to the first buffer 233 to process new object data is called mode conversion. A first PCS input during mode conversion has no data or is a dummy PCS. Accordingly, a graphic data processing apparatus 230 decodes only necessary objects of the first display set 305 through 320 until a subsequent mode conversion and stores the necessary objects in the first buffer 233. Therefore, there is no data in the second buffer 234.

FIG. 4B is a diagram illustrating a state in which a second display set 325 through 330 having a PCS 325 with the page_id=2 is stored in the buffers.

Referring to FIG. 3, the second display set 325 through 330 having the PCS 325 with the page_id=2 includes the PCS 325 and an END 330. The second display set 325 through 330 includes the page composition information to display the objects of the first display set 305 through 320 with the page_id=1 stored in the first buffer 233 on the display screen. Accordingly, the PCS 325 with the page_id=2 includes position information indicating which graphic objects are displayed and where the graphic objects are displayed on the display screen. The image controller 236 controls the first buffer 233 using the page composition information of the PCS 325 with the page_id=2 so that the graphic objects corresponding to the ODS 310 with the object_id-1 and the ODS 315 with the object_id=2 are transmitted to the second buffer 234 and the screen may be composed. At a time indicated by the PTS information included in the PCS 325, graphic screen data of a completely composed screen is output from the second buffer 234 to the display device.

FIG. 4C is a diagram illustrating a state in which a third display set 335 through 345 having a PCS 335 with the page_id=3 is stored in the buffers.

Referring to FIG. 3, the third display set 335 through 345 having the PCS 335 with the page_id=3 includes the PCS 335, an ODS 340 with the object_id=2, and an END 345. The ODS 340 included in the third display set 335 through 345 having the PCS 335 with the page_id=3 has a common object_id as that of the ODS 315 of the ODSs 310 and 315 of the first display set 305 through 320 having the PCS 305 with the page_id=1. Since the ODS 340 having the common object_id as that of the ODS 315 overlies the ODS 315, the ODS 340 consequently performs an update operation. That is, although the page composition information of the PCS does not change, an updated object is reflected on the display screen such that at a time indicated by PTS information of the pertinent PCS, graphic data, which is stored in the second buffer 234, of a completely composed screen is output to the display device.

FIG. 4D is a diagram illustrating a state in which a fourth display set 350 through 360 having a PCS 350 with the page_id=4 is stored in the buffers.

Referring to FIG. 3, the fourth display set 350 through 360 having the PCS 350 with the page_id=4 includes the PCS 350 containing new page composition information, an ODS 355 with the object_id=3, and an END 360. After the graphic processing apparatus 230 stores data corresponding to each segment in the first buffer 233, the second buffer 234, and the page composition buffer 235, the graphic processing apparatus 230 outputs data, which is stored in the second buffer 235, of a completely composed screen to the display device at a time indicated by PTS information of the PCS 350 with the page_id=4.

FIGS. 5A-5D are diagrams illustrating a process of inputting and outputting data to and from the buffers in accordance with a passage of time.

Referring to FIGS. 5A-5D, all of the PCS 305, ODS 310 and 315 and END 320 of the first display set 305 through 320 are stored in the coded data buffer 231 at a time 510 indicated by PTS information included in an MPEG-2 TS header of a pertinent packet, and are output from the coded data buffer 231, decoded in the decoder 232, and stored in the first buffer 233 at time 550 and at time 560 indicated by PTS information of the respective ODSs 310 and 315. As previously explained, a time when one object is output from the coded data buffer 231 theoretically is equal to a time when the object is decoded in the decoder 232 and stored in the first buffer 233. However, in actuality, since time is taken to decode the object, the value of the time 560 indicated by the PTS information of the ODS 315 with the object_id=2 is greater than that of the time 550 indicated by the PTS information of the ODS 310 with the object_id=1.

Accordingly, a first graphic object of the ODS 310 with the object_id=1 is output from the coded data buffer 231 and is decoded and stored in the first buffer 233 at the time 550 indicated by the PTS information of the ODS 310 with the object_id=1. A second graphic object of the ODS 315 with the object_id=2 is output from the coded data buffer 231, and then decoded and stored in the first buffer 233 at the time 560 indicated by the PTS information of the ODS 315 with the object_id=2.

All the PCS 325 and END 330 of the second display set 325 through 330 are stored in the coded data buffer 231 at a time 520 indicated by PTS information included in a header of the pertinent packet. The PCS 325 is decoded in the decoder 232 and stored in the page composition buffer 235. The image controller 236 controls the first buffer 233 to transmit the object necessary to compose the pertinent screen from the first buffer 233 to the second buffer 234 based on the page composition information. A time when the object stored in the first buffer 233 is transmitted to the second buffer 234 and the screen composition starts, is the same as a time indicated by the PTS information of the ODS, which is stored last in the first buffer 233.

However, since the PCS 305 of the first display set 305 through 320 is a dummy PCS with no page composition information, the ODS 315 with the object_id=2, which is stored last, is not transmitted to the second buffer 234 at the time indicated by the PTS information thereof, and not used in the screen composition. When the image controller 236 uses the PCS information of the second display set 325 through 330 which is decoded and stored in the page composition buffer 235, the first graphic object with the object_id=1 and the second graphic object with the object_id=2, which are necessary for the screen composition, are transmitted from the first buffer 233 to the second buffer 234 such that the screen composition starts. At a time 590 indicated by PTS information of the PCS 325 with the page_id=2, the graphic screen data of a completely composed screen is output to the display screen.

All of the PCS 335, ODS 340, and END 345 of the third display set 335 through 345 are stored in the coded data buffer 231 at a time 530 indicated by PTS information included in a header of the pertinent packet and are output from the coded data buffer 231, decoded, and immediately stored in the first buffer 233 at a time 570 indicated by the PTS information of the ODS 340 of the third display set 335 through 345. At this time, since the ODS 340 included in the third display set 335 through 345 uses a common object_id as that of the ODS 315, which has already been stored in the first buffer 233, the ODS 340 overlies the previously stored second object of the ODS 315. As a result, an updated second object is obtainable.

However, since the PCS 335 with the page_id=3 performs the screen composition using the ODSs 310 and 340 with the object_id=1 and the object_id=2, the ODS 340 with the object_id=2 is stored last in the first buffer 233 at the time indicated by the PTS information of the ODS 340, and is simultaneously transmitted to the second buffer 234 to be used in the screen composition. At a time 591 indicated by the PTS information of the PCS 335 with the page_id=3, a page of a completely composed screen is output to the display device. At this time, the second buffer 234 maintains a display screen output which is composed based on the page composition information of the PCS 325 with the page_id-2 until the time indicated by the PTS information of the PCS 335 with the page_id=3.

Furthermore, all of the PCS 350, ODS 355, and END 360 of the fourth display set 350 through 360 are stored in the coded data buffer 231 at a time 540 indicated by the PTS information included in a header of the pertinent packet and are output from the coded data buffer 231, decoded, and immediately stored in the first buffer 233 at a time 580 indicated by the PTS information of the ODS 355 of the fourth display set 350 through 360. At a time 592 indicated by the PTS information of the PCS 350 with the page_id=4, a page of a completely composed screen is output to the display device. At this time, the second buffer 234 maintains a display screen output which is composed based on the page composition information of the PCS 335 with the page_id-3 until the time indicated by the PTS information of the PCS 350 with the page_id=4. Accordingly, the second buffer 234 includes a preparing buffer 610 and a display buffer 620 as shown in FIG. 6.

FIG. 6 is a detailed block diagram of the second buffer 234.

Referring to FIG. 6, the second buffer 234 includes the preparing buffer 610 and the display buffer 620. The preparing buffer 610 is a memory used in placing, with reference to the page composition information, objects input from the first buffer 233 at predetermined positions of the display screen. The display buffer 620 is a memory used in displaying data of the prepared display screen. At a time indicated by the PTS information of the PCS 305, 325, 335 and 350, operations of the preparing buffer 610 and the display buffer 620 are exchanged and data of the completely composed screen is finally output to a display device 630.

In further detail with reference to FIGS. 4B and 4C, when the screen composition is completed with reference to the information of the PCS 325 with the page_id=2, contents of the second buffer 234 of FIG. 4B are stored in the display buffer 620, and output to the display device 630. Screen composition proceeds in the preparing buffer 610 with reference to the information of the PCS 325 with the page_id=3. At the time indicated by the PTS information of the PCS 335 with the page_id=3, the operations of the preparing buffer 610 and the display buffer 620 are exchanged such that the contents of the second buffer 234 shown in FIG. 4C are output to the display device 630 and the data of the fourth display set 350 through 360 is input to the preparing buffer 610 in a common manner as described above so as to be used in the screen composition.

FIG. 7 is a flow chart illustrating an operation of outputting graphic display data of a completely composed page to the display device.

In operation S710, graphic data is received. In operation S720, page composition information which describes a page composition of the graphic data is received. In operation S730, graphic screen data which is composed with reference to the page composition information of the graphic data is output to the display screen according to presentation information which indicates when the graphic screen data is output to the display screen. The presentation information is recorded in a page composition segment including the page composition information. Further, if a plurality of graphic data values exists, a graphic display screen composition starts with reference to the presentation information of a respective one of the graphic data values, among the plurality of graphic data values, that was last input.

FIG. 8A is a flow chart illustrating an operation of outputting a decoded graphic object.

In operation S810, a graphic object of which a graphic data screen is composed is received. In operation S820a, a decoded graphic object is output according to presentation information indicating when the graphic object is decoded and output.

FIG. 8B is a flow chart illustrating an operation of inputting a graphic object to the decoder.

In operation S810, a graphic object of which a graphic screen is composed is received. In operation S820b, the graphic object is input to the decoder 232 to be decoded according to presentation information indicating when the graphic object is input to the decoder 232.

In theory, assuming that a decoding time in the decoder 232 is 0, FIGS. 8A and 8B show that a time when the graphic object is input to the decoder 232 is the same as a time when the graphic object is output from the decoder 232. The presentation information is recorded in an object display segment having the graphic object. Thus, according to the invention, if a plurality of graphic objects exist, respective time values indicated by presentation information of the graphic objects have a predetermined time interval therebetween.

This invention may be embodied in a general purpose digital computer by running a program from a computer-readable medium, including but not limited to, storage media such as magnetic storage media (e.g., ROMs, floppy discs, hard discs, etc.), optically readable media (e.g., CD-ROMs, DVDs, etc.), and carrier waves (e.g., transmissions over the Internet). The computer-readable medium may be dispersively installed in a computer system connected to a network, and stored and executed as computer-readable code by a distributed computing environment.

As described above, if graphic data composition information and presentation information are used, a graphic object is reusable during graphic data processing. Accordingly, a time taken to process graphic data is reducible and memory area may be saved.

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 this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Claims

1. An apparatus for processing graphic data, the apparatus comprising:

a reader to read data from an information storage medium, the data comprising a display set comprising an object segment and a composition segment, segment and a plurality of object segments corresponding to the composition segment, each of the plurality of object segment segments comprising a plurality of graphic object data respectively defining a plurality of graphic objects graphic object data defining a graphic object, the graphic object data to be used by the apparatus in composing a graphic screen to be displayed on a display device, and the plurality of object segments thereby comprising a plurality of graphic object data defining a plurality of graphic objects, the composition segment comprising composition information for at least some one of the plurality of graphic objects defined by the plurality of graphic object data, the composition information to be used by the apparatus in composing the graphic screen, the composition information specifying how the at least some one of the plurality of graphic objects are is to be displayed on the graphic screen;

a first buffer to store the plurality of graphic object data for a predetermined time so that the plurality of graphic object data remain available for use for the predetermined time;

a second buffer to store the composition information; and

a third buffer to store composed graphic data defining the graphic screen to be output to the display device, the composed graphic data being composed from at least some one of the plurality of graphic object data stored in the first buffer;

wherein the composition information comprises position information indicating where the at least some one of the plurality of graphic objects are is to be displayed on the graphic screen.

2. The apparatus of claim 1, wherein each of the plurality of graphic object data is identified by a respective object identifier.

3. The apparatus of claim 1, wherein the first buffer stores the plurality of graphic object data until the first buffer is reset.

4. A non-transitory information storage medium for use by a computer, the non-transitory information storage medium comprising:

a display set comprising an object segment and a composition segment, segment and a plurality of object segments corresponding to the composition segment, each of the plurality of object segment segments comprising a plurality of graphic object data respectively defining a plurality of graphic objects graphic object data defining a graphic object, the graphic object data to be used by the computer in composing a graphic screen to be displayed on a display device, and the plurality of object segments thereby comprising a plurality of graphic object data defining a plurality of graphic objects, the composition segment comprising composition information for at least some one of the plurality of graphic objects defined by the plurality of graphic object data, the composition information to be used by the computer in composing the graphic screen, the composition information specifying how the at least some one of the plurality of graphic objects are is to be displayed on the graphic screen;

wherein the composition information comprises position information indicating where the at least some one of the plurality of graphic objects are is to be displayed on the graphic screen.

5. The non-transitory information storage medium of claim 4, wherein each of the plurality of graphic object data is identified by a respective object identifier.