Computer graphics processing and selective visual display system – Display peripheral interface input device – Light pen for fluid matrix display panel
Reexamination Certificate
1998-10-21
2001-10-02
Luu, Matthew (Department: 2672)
Computer graphics processing and selective visual display system
Display peripheral interface input device
Light pen for fluid matrix display panel
C345S182000, C345S111000, C348S468000, C348S461000, C348S569000
Reexamination Certificate
active
06297797
ABSTRACT:
BACKGROUND OF THE INVENTION
The entire contents of Japanese Patent Application No. 9-298748 filed on Oct. 30, 1997 and Japanese Patent Application No. 10-88787 filed on Apr. 1, 1998 are incorporated herein by reference.
The present invention relates to a computer system having a function of displaying closed caption data included in a data stream that has been digitally compressed and encoded on a display monitor, and a closed caption display method used in that system.
In recent years, along with the development of computers and multimedia techniques, various kinds of so-called multimedia compatible personal computers have been developed. A personal computer of this type has a function of reproducing motion pictures and audio data in addition to text and graphics data.
With the advent of such multimedia computers, a DVD has gained a lot of attention as an alternative storage medium to a CD-ROM. A single DVD-ROM medium can record data of about 4.7 Gbytes about seven times the capacity of the existing CD-ROM on one side, and can record data of about 9.4 Gbytes in case of two-sided recording. Using such DVD-ROM media, titles such as movies including a large volume of video information can be reproduced with high quality on the computer.
Video information recorded on a DVD-ROM medium consists of two kinds of data, i.e., presentation data and navigation data. The presentation data is a set of video objects to be reproduced, and consists of video, subpicture, and audio data. The video data is compressed and encoded by MPEG2. As the coding schemes of subpicture and audio data, runlength coding, AC-3, and the like are supported. The subpicture data is bitmap data, and is used for displaying superimposed dialogues of a movie, selection items on a menu window, and the like. One video object can contain video data for one channel, audio data for a maximum of eight channels, and subpicture data for a maximum of 32 channels.
The navigation data is reproduction control data for controlling the reproduction sequence of the presentation data, and navigation commands can be embedded in this data. The navigation commands are used for changing the reproduction contents or order of video data. Using the navigation commands, a title creator can define various branch structures in his or her title, and can create an interactive title.
When a title stored in a DVD is to be reproduced on a computer, data read out from a DVD-ROM drive is loaded onto a main memory of the computer, and is then transferred to an MPEG2 decoder. The MPEG2 decoder descrambles an encoded video data stream, which has been scrambled to prevent the title from being illicitly copied, and then decodes to expand the encoded video data stream. The decoded video data is displayed on a display monitor or an external TV under the control of a display controller.
A title stored in a DVD is normally created for the purpose of reproduction on a home TV using a home-use player. For this reason, the contents of the title often include closed caption data which is popularly used in a TV video signal, in addition to subpicture data.
The closed caption data is character data superposed on line
21
during the vertical blanking period of the TV video signal, and in the United States, most of home TVs have a function of displaying the closed caption data. Upon displaying the closed caption data, the viewer can confirm the contents of the TV video not only by audio information but also character information. In an MPEG2 stream that forms a DVD title, closed caption character data is called “line
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data”.
As described above, as a method of reproducing a DVD title using a computer, there are two methods, i.e., a method of connecting a home TV to the NTSC output of the computer, and watching the title on that TV, and a method of directly watching the title on a display monitor of the computer.
A case will be examined below wherein a DVD title that contains closed caption character data as line
21
data is reproduced.
When the contents of the DVD title are watched using a home TV, the closed caption character data can be displayed on the TV screen as character information that helps viewing the video, as long as the TV is closed caption compatible. However, when the contents of the DVD title are directly watched on the display monitor of the computer, its display screen is controlled by a display controller which is incompatible with closed caption, and the viewer cannot watch closed caption information.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide a computer system that can display closed caption data contained in a video data stream such as a DVD title, that has been digitally compressed and encoded, on a display monitor of a computer, and a closed caption display method used in the system.
In order to achieve the above object, according to the present invention, there is provided a computer system having a decoder for decoding digitally compressed and encoded data, and a display controller which has a video input port for receiving data decoded by the decoder, and displays data input from the video input port on a display monitor, the decoder including means for detecting closed caption character data from the digitally compressed and encoded data or decoded result data thereof, and means for issuing an interrupt signal to pass the detected closed caption character data to the display controller, the system comprising output means for acquiring the closed caption character data from the decoder and outputting the character data to the display controller in response to the interrupt signal, character information corresponding to the acquired closed caption character data being displayed on the display monitor.
In this computer system, when digitally compressed and encoded video data includes closed caption character data as line
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data, the presence of the closed caption character data is detected by the decoder, and that data is passed on to the output means using an interrupt signal. The output means converts the closed caption character data received from the decoder into character information, and writes it in an image memory, or displays the character information corresponding to the closed caption character data on a display monitor using an On Screen Display (OSD) function of the display controller. Using a mechanism for passing the closedt caption data detected by the decoder to the display controller via the output means, closed caption display can be controlled by software such as a DVD reproduction control program or driver. Hence, even in a system that uses an existing display controller incompatible with closed caption, character information can be displayed on the screen as in a closed caption compatible TV.
Since the closed caption display can be controlled by software, closed caption character data contained in digitally compressed and encoded data can be translated into another language by the intervention of a language translation program, and the translation result can be displayed as character information.
Also, according to the present invention, there is provided a computer system having a decoder for decoding digitally compressed and encoded data, and a display controller which has a video input port for receiving data decoded by the decoder, and displays data input from the video input port on a display monitor, the decoder including means for detecting closed caption character data from the digitally compressed and encoded data or decoded result data thereof, means for issuing an interrupt signal to pass the detected closed caption character data to the display controller, and on-screen display means for synthesizing various kinds of information designated by an external on-screen display command on frame data formed by the decoded data, and outputting the synthesizing result to the video input port of the display controller, the system comprising means for acquiring the closed caption character data from the decoder, and issuing an on-screen display command for designating di
Ishibashi Yasuhiro
Takeuchi Yoshihiko
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Kabushiki Kaisha Toshiba
Luu Matthew
Sajous Wesner
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