Method of displaying sub-picture in DVD player

1. A method of reproducing a sub-picture in a reproducing apparatus for display thereof, comprising:

decoding video data within a recording medium according to a play speed of a trick play mode of the reproducing apparatus via the reproducing apparatus and displaying the decoded video data; and

selectively decoding at least one of a plurality of sub-picture data within the video data that is being decoded via the reproducing apparatus and displaying the decoded sub-picture data during a time displayed in a normal play mode,

wherein a display-off time point of the decoded sub-picture data depends on a value found by adding a start time of a corresponding sub-picture display control sequence to a first PTS (presentation time stamp) of the video data that is being decoded,

wherein, when next video data is displayed, sub-picture data within the next video data is skipped while the displayed sub-picture data is displayed, and a next sub-picture data to be decoded is selected based on the display-off time point and the play speed of the trick play mode,

wherein the selected next sub-picture data is decoded and displayed based on the first PTS of video data that is being decoded after the display-off time point, when a STC (system time clock) is greater than a PTS of the decoded next sub-picture, and

wherein the STC is not greater than the first PTS of video data that is being decoded after the display-off time point.

2. The method of claim 1 , wherein the video data within the recording medium is VOBU (video object unit).

3. The method of claim 1 , wherein the decoded sub-picture data is a first sub-picture data of a plurality of the sub-picture data within the video data that is being decoded.

4. The method of claim 1 , wherein other sub-picture data are not decoded but skipped while the decoded sub-picture data is displayed.

5. The method of claim 1 , wherein another sub-picture data is decoded after the time of displaying the decoded sub-picture data passes.

6. The method of claim 5 , wherein the another sub-picture data is arranged next to the displayed sub-picture data.

7. The method of claim 1 , wherein the start time of the corresponding sub-picture display control sequence is a value decoded in a next sub-picture display control sequence.

8. A method of reproducing a sub-picture in a reproducing apparatus for display thereof, the method comprising:

decoding a video pack within a VOBU (video object unit) of a recording medium according to a play speed of a trick play mode of the reproducing apparatus via the reproducing apparatus and displaying the decoded video pack;

selecting a sub-picture pack to be decoded from a plurality of sub-picture packs within the VOBU via reproducing apparatus; and

decoding the selected sub-picture pack via the reproducing apparatus and displaying the decoded sub-picture pack during a time displayed in a normal play mode,

wherein a display-off time point of the decoded sub-picture pack depends on a value found by adding a start time of a corresponding sub-picture display control sequence to a first PTS (presentation time stamp) of the video pack that is being decoded,

wherein, when a video pack within a next VOBU is displayed, a sub-picture pack within the next VOBU is skipped while the displayed sub-picture pack is displayed, and a next sub-picture pack to be decoded is selected based on the display-off time point and the play speed of the trick play mode,

wherein the selected next sub-picture data is decoded and displayed based on the first PTS of video data that is being decoded after the display-off time point, when a STC (system time clock) is greater than a PTS of the decoded next sub-picture, and

wherein the STC is not greater than the first PTS of video data that is being decoded after the display-off time point.

9. The method of claim 8 , wherein the selected sub-picture pack to be decoded is a first sub-picture pack showing up right next to the decoded video pack.

10. The method of claim 8 , wherein a subsequently inputted sub-picture pack is not decoded but skipped while the selected sub-picture pack is displayed.

11. The method of claim 8 , wherein if the time of displaying the selected sub-picture pack passes, a next sub-picture pack subsequently inputted is decoded.

12. The method of claim 8 , wherein the start time of the corresponding sub-picture display control sequence is a value decoded in a next sub-picture display control sequence.

13. The method of claim 8 , wherein the sub-picture pack includes caption information therein.

14. A data reproducing device, comprising:

a stream demultiplexer configured to separate a video stream, sub-picture stream, and navigation stream from data read out of a disc;

a video decoder configured to decode the separated video stream according to a play speed of a trick play mode;

a size transforming unit configured to transform a size of the video-decoded data to fit a display device;

a sub-picture decoder configured to selectively decode at least one of a plurality of sub-picture data within video data of the video stream;

a navigation data processor configured to process the separated navigation data; and

a mixer configured mix and output the decoded/size-transformed video data and the sub-picture data,

wherein a display-off time point of the decoded sub-picture data depends on a value found by adding a start time of a corresponding sub-picture display control sequence to a first PTS (presentation time stamp) of the video data that is being decoded,

wherein, when next video data is displayed, sub-picture data within the next video data is skipped while the displayed sub-picture data is displayed, and a next sub-picture data to be decoded is selected based on the display-off time point and the play speed of the trick play mode,

wherein the selected next sub-picture data is decoded and displayed based on the first PTS of video data that is being decoded after the display-off time point, when a STC (system time clock) is greater than a PTS of the decoded next sub-picture, and

wherein the STC is not greater than the first PTS of video data that is being decoded after the display-off time point.