Abstract:
A method and device of automatic detection and modification of subtitle position comprises the steps of comparing an active display area parameter of a displaying device to an original subtitle control signal to generate a comparison result, and outputting a targeted subtitle control signal to modify the position of the subtitle depends on the comparison result so that the subtitle is guaranteed to display in the active display area. Accordingly, the subtitle position detection and modification method and device may not only as a solution of improper subtitle display position arrangement, but also excite the viewer&#39;s joy of the sight and eliminate the inconvenience of the complicated adjusting operations.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The invention relates to a subtitle position detection and modification method and device, in particular, to the method and device of subtitle position detection and modification according to an active display area of displaying device. 
     2. Related Art 
     The species, stability, capacity, application and playing device of storage medium evolving into variety since the technology progressing and the higher demand of quality of audio and video. For example, the digital versatile disc (DVD) applies MPEG compression technique to create high quality dynamic image, and provides the sub picture/subtitle mechanism for the purpose of improving interaction between the digital contents and the audience. Moreover, the sub picture/subtitle file includes many subtitles and menus so that the DVD may support at most  32  subtitle streams, and the digital content provider can design various menus, tags, auxiliaries for aurally handicapped person auxiliary, simple animation, and subtitles supporting multi-languages mode. 
     In practice, the source of video, audio, and sub picture/subtitle file encoded by corresponding encoder respectively, and then mixed up to form a DVD image file stored in a DVD disc, whereas the playing system decodes corresponding encoded data stream and then forwards to a displaying device such as a television.  FIG. 1  is a schematic block diagram of the playing procedures of a DVD player according to the prior art, herein a data stream separating unit  110  of the playing system separates MPEG video data stream, audio data stream, and sub picture data stream from the source data stream of the data source  100 , and then decoding them by corresponding decoder respectively. For instance, the MPEG video data stream is decoded by a MPEG decoder  120 , the audio data stream is decoded by an AC-3 decoder  130 , and the sub picture data stream is decoded by a sub picture decoder  140 . Hence the decoded MPEG video data stream and sub picture data stream are mixed up by a mixer  150  and converted by a first D/A converter  160  to generate a video output to the playing unit  180 , whereas the decoded audio data stream is converted by a second D/A converter  170  to generate a audio output to the playing unit  180 . 
     The subtitle file includes the bitmap format subtitle data and subtitle control signal, and the DVD player reading and decoding the subtitle file from the data source  100  to obtain the bitmap format subtitle data, binding it with image duly to display in the preset subtitle displaying position depends on the corresponding parameters, such as time and position, and then generating and transmitting the frames within subtitles to the display device. 
     However, the subtitles or parts of them may not adapt to the active display area of the displaying device which is probably caused by improper arrangement of subtitle during DVD producing process, and it will affect the delights of audience, increase the inconvenience, and so much as decrease the quality of the frame. It is therefore a subjective of the invention to provide the subtitle position detection and modification method and device as a solution of improper subtitle display position arrangement, but also eliminate the inconvenience of the complicated adjusting operations and improve vision qualities and feelings of user. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing, the invention is to provide a device of automatic detection and modification of subtitle position, which comprises a comparison unit and a control signal adjusting unit. In the invention, the comparison unit comparing an active display area parameter of a displaying device to an original subtitle control signal such as to generate a comparison result; and the control signal adjusting unit outputting a targeted subtitle control signal to modify an original subtitle position such as to display in the active display area according to the comparison result. Herein, the device includes an active display area detecting unit for detecting and outputting the active display area parameter to the comparison unit, or an active display area receiving unit for the user to input the active display area parameter. Besides, the device includes a decoding module for decoding a subtitle source such as to generate targeted subtitle data and the original subtitle control signal. Moreover, the device further includes an overlapping unit for overlapping a MPEG-2 or MPEG-4 encoded and decoded video signal, a targeted subtitle data, and the targeted subtitle control signal to output to a displaying device, thus the original subtitle data is guaranteed to display in the active display area. 
     In addition, the invention provides an method of automatic detection and modification of subtitle position, which comprises the steps of comparing an active display area parameter of a displaying device to an original subtitle control signal and then generating a comparison result, and then outputting a targeted subtitle control signal according to the comparison result such as to modify an original subtitle position to a preset subtitle displaying position of the active display area. In addition, the method includes a step of detecting the displaying device to obtain the active display area parameter, or receiving the active display area parameter inputted by the user from an active display area receiving unit. Moreover, the method includes steps of decoding a subtitle source such as to generate a targeted subtitle data and the original subtitle control signal, and overlapping the video signal, a targeted subtitle data, and the targeted subtitle control signal such as to output to the displaying device. In such a case, the original subtitle data can be displayed in the active display area of the display device so that the viewer can enjoy better sight of the medium contents according to the assistance of the subtitle. 
     Furthermore, the invention provides a device of automatic detection and modification of subtitle position applying for a digital playing system, which comprises a medium receiving unit for receiving a digital medium and file such as a DVD disc with MPEG-2 or MPEG-4 encoded format file, a stream separating unit for separating data streams of the digital medium; a decoding module for decoding the data streams of the digital medium such as to generate a targeted subtitle data and an original subtitle control signal; a comparison unit for comparing an active display area parameter of a displaying device to an original subtitle control signal to generate a comparison result; and a control signal adjusting unit for outputting a targeted subtitle control signal to modify an original subtitle position to display in the active display area according to the comparison result. 
     As mentioned above, the subtitle position detection and modification method and device may not only as a solution of improper subtitle display position arrangement, but also excite the viewer&#39;s joy of the sight and eliminate the inconvenience of the complicated adjusting operations. Hence, the invention has extra auxiliary effects on aurally handicapped person since the subtitle can be displayed in the active display area of the displaying device, such as a monitor or a television. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In view of the subtitles or parts of them may not adapt to the active display area of the displaying device which is probably caused by improper arrangement of subtitle during DVD producing process, the present invention provides a method and device of automatic detection and modification of subtitle position, and the invention will become more fully understood from the detailed description given herein below illustration only, and thus is not limitative of the present invention, and wherein: 
         FIG. 1  is a schematic block diagram showing the playing procedures of a DVD player according to the prior art. 
         FIG. 2  is a schematic block diagram of the device for automatic detection and modification of subtitle position according to a preferred embodiment of the invention. 
         FIG. 3  is a flow chart showing the steps of the method for automatic detection and modification of subtitle position according to a preferred embodiment of the invention. 
         FIG. 4  is a schematic view showing the subtitle position according to the original subtitle control signal. 
         FIG. 5  is a schematic block diagram of the device for automatic detection and modification of subtitle position according to another preferred embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings. 
       FIG. 2  is a schematic block diagram of the device for automatic detection and modification of subtitle position according to a preferred embodiment of the invention. In the embodiment, the device for automatic detection and modification of subtitle position comprises a comparison unit  240  for comparing an active display area parameter of a displaying device  280  to an original subtitle control signal to generate a comparison result, and a control signal adjusting unit  260  for outputting a targeted subtitle control signal, such as a coordinate of a preset subtitle displaying position of the active display area, to modify an original subtitle position to display in the active display area according to the comparison result. Furthermore, the device includes an overlapping unit  270  for overlapping a video signal source  210  having a video signal encoded and decoded in MPEG-2 or MPEG-4 format, a targeted subtitle data, and the targeted subtitle control signal, and then the output of overlapping unit  270  may be transmitted to a displaying device  280 . 
     Again, with reference to  FIG. 2 , the device of the embodiment further includes a decoding module  250  for decoding a subtitle source  200  such as to generate a targeted subtitle data and an original subtitle control signal, wherein the targeted subtitle data is sent to the overlapping unit  270 , and the original subtitle control signal is sent to the comparison unit  240 . Furthermore, the device of the embodiment further includes an active display area detecting unit  230  for detecting and outputting the active display area parameter of the displaying device  280  to the comparison unit  240 . 
     Besides, the device of another embodiment further includes an active display area receiving unit  220  for receiving the active display area parameter inputted in a inputting device (not shown in  FIG. 2 ) such as a remote controller, a button, or a panel by the user, and outputting the active display area parameter to the comparison unit  240 . 
       FIG. 3  is a flow chart showing the steps of the method for automatic detection and modification of subtitle position according to a preferred embodiment of the invention. Firstly, comparing an active display area parameter of a displaying device to an original subtitle control signal, and then generating a comparison result in step  320 . Secondly, outputting a targeted subtitle control signal to modify the original subtitle position to a preset subtitle displaying position of the active display area according to the comparison result which indicates whether the original subtitle position needs to be adjusted or not in step  330 . Lastly, overlapping a video signal, a targeted subtitle data, and the targeted subtitle control signal and outputting to the displaying device in step  340 . In the embodiment, the method further includes that detecting the displaying device to obtain the active display area parameter in step  310 . Besides, In another embodiment, the method includes that receiving the active display area parameter from an active display area receiving unit by the user&#39;s demand. 
       FIG. 4  is a schematic view showing the subtitle position according to the original subtitle control signal. In the embodiment, displaying system  400  having an active display area  405 , and the active display area parameter of the active display area  405  includes a first top left coordinate (0, 0), a first top right coordinate (A, 0), a first bottom left coordinate (0, B) and a first bottom right coordinate (A, B), and the original subtitle control signal, such as one of  421  to  430 , comprises a second top left coordinate (W, X), a second top right coordinate (Y, X), a second bottom left coordinate (W, Z) and a second bottom right coordinate (Y, Z). It&#39;s noted that the active display area parameter, the position, coordinate value and number of the original subtitle position, and the position, coordinate value and number of the preset subtitle displaying position are not limited to that shown in  FIG. 4 . In order to guarantee that the subtitle is displayed in the active display area  405 , Once X is less than zero, W is less than zero, Z is greater than B, or Y is greater than A so that the original subtitle position is totally or partially out of the active display area  405 , the comparison result is outputted to modify the original subtitle position. Therefore if the comparison result indicates that the original subtitle position needs to be adjusted, the process of outputting the targeted subtitle control signal to modify the original subtitle position to a preset subtitle displaying position of the active display area, such as  410  or  420 , in step  330  of  FIG. 3 . It&#39;s noted that if there exist many preset subtitle displaying position, the selection of the preset subtitle displaying position depends on the shortest distance between the original subtitle position modified by the targeted subtitle control signal and the preset subtitle displaying position. And then the video signal, the targeted subtitle data, and the targeted subtitle control signal could be overlap and output to the displaying device in step  340 , and the subtitle data will be display in the active display area  405 . Besides, if the comparison result indicates that the original subtitle position needs not to be adjusted in step  330 , overlapping the video signal, the targeted subtitle data and the original subtitle control signal in step  340 , and then outputting to the display device  400  as ordinary operation. 
       FIG. 5  is a schematic block diagram of the device for automatic detection and modification of subtitle position according to another preferred embodiment of the invention, and the device applying for a digital playing system  500 , such as a DVD player. In the embodiment, the device comprises a medium receiving unit  510  for receiving a digital medium or file such as a DVD disc with the MPEG-2 encoded format file, and a DivX file supporting subtitle format and encoded in MPEG-4 format; a stream separating unit  520  for separating data streams of digital medium or file; a decoding module  530  for decoding the data streams of the digital medium such as to generate a targeted subtitle data and an original subtitle control signal; a comparison unit  540  for comparing an active display area parameter of a displaying device to an original subtitle control signal to generate a comparison result; and a control signal adjusting unit  550  for outputting a targeted subtitle control signal to modify an original subtitle position to display in the active display area according to the comparison result. Besides, if the comparison result indicates that the original subtitle position needs not to be adjusted, overlapping the video signal, the targeted subtitle data and the original subtitle control signal, and then outputting to the display device as ordinary operation. 
     The method and device of automatic detection and modification of subtitle position can be accomplished by the firmware and the logic circuits. 
     Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the invention.