Abstract:
A scrolling subtitle detecting device and method, which the device includes a receiving unit receiving a subtitle size data, a first subtitle data and a second subtitle data; and a detecting module detecting the first subtitle data and the second subtitle data to obtain a difference according to the subtitle size data for judging a scrolling information of the second subtitle data. Accordingly, the scrolling subtitle detecting device and method may eliminate serration at the edge of the subtitle while the subtitle having scrolling and scaling effects simultaneously, but also excite the viewer&#39;s joy of the sight and improve the quality of the playing subtitle.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of Invention  
         [0002]     The present invention relates to a scrolling subtitle detecting device and method, and in particular, to the detecting device and method which detects a first subtitle data and a second subtitle data for obtaining a scrolling information of the second subtitle data.  
         [0003]     2. Related Art  
         [0004]     The quality becomes an essential factor in purchasing since the technology progressing and the living standard goes higher. The most popular information technical product is the audio/video player of the multimedia player-related. Accordingly, the corresponding image effects turn into a focus on researches of audio/video playing.  
         [0005]     The common image effect is the subtitle processing, especially the subtitle scrolling up/down and the subtitle scaling up/down. In the conventional subtitle scrolling, the subtitle decoder decodes the subtitle data stream of a disc and then generates the subtitle data with a plurality blocks and start address for a audio/video player to achieve the subtitle scrolling effect by adjusting the start address. In addition, the conventional subtitle scaling up/down replicating and appending to the blocks and extracting the blocks of the fixed position respectively.  
         [0006]     However, while the subtitle having scrolling and scaling effects simultaneously, the serration occurs in the edge of the subtitle since the audio/video player accesses the start address drawn out in the scaling process, and the subtitle and image quality in conflict with the user&#39;s demand.  
         [0007]     Accordingly, the avoidance of the audio/video player accessing the start address drawn out in the scaling process and the elimination of serration is the requirement of the subtitle effect. Hence, a scrolling subtitle detecting device and method is proposed as one solution of the subtitle serration and the scaling and scrolling effect co-operating problem.  
       SUMMARY OF THE INVENTION  
       [0008]     In view of the foregoing, the invention provides a scrolling subtitle detecting device, which includes a receiving unit for receiving a subtitle size data, a first subtitle data and a second subtitle data; and a detecting module for detecting the first subtitle data and the second subtitle data to obtain a difference according to the subtitle size data for judging a scrolling information of the second subtitle data.  
         [0009]     In addition, the invention provides a scrolling subtitle detecting method including the steps of receiving a subtitle size data, a first subtitle data and a second one; and obtaining a difference from detecting the first subtitle data and the second one according to the subtitle size data for judging a scrolling information of the second subtitle data.  
         [0010]     Moreover, the invention provides a scrolling subtitle detecting device and method having a receiving unit and a detecting module for obtaining a scrolling information including the scrolling up, scrolling down and scrolling quantity of the subtitle of the second subtitle data through detecting the first subtitle data and the second one for the eliminating the serration of the scrolling subtitle.  
         [0011]     As mentioned above, the scrolling subtitle detecting device and method detecting blocks of the first subtitle data and the second one of the receiving unit; recording times of the second one equaling to the first one in a counter; comparing the counter with a threshold for judging whether the second one is a scrolling subtitle or not; comparing a start address of blocks of the first subtitle data with the one of the second subtitle data for obtaining the difference while the second subtitle data is the scrolling subtitle; and judging a scrolling information of the second subtitle data according to the difference for eliminating the serration of subtitle and improving the playing quality of the subtitle. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     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:  
         [0013]      FIG. 1  is a block diagram showing a scrolling subtitle detecting device according to a preferred embodiment of the invention.  
         [0014]      FIG. 2  is a block diagram showing a scrolling subtitle detecting device according to another preferred embodiment of the invention.  
         [0015]      FIG. 3  is a flow chart showing the steps of a scrolling subtitle detecting method according to another preferred embodiment of the invention.  
         [0016]      FIG. 4  is a schematic view showing the detecting module of the invention.  
         [0017]      FIG. 5  is a block diagram showing a scrolling subtitle detecting device applying to a digital medium player according to another preferred embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0018]     The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.  
         [0019]     With reference to  FIG. 1 , a block diagram showing a scrolling subtitle detecting device according to a preferred embodiment of the invention includes a receiving unit  16  for receiving a subtitle size data, a first subtitle data and the second one, and a detecting module  18  for detecting the first subtitle data and the second one of the receiving unit  16  to obtain a difference according to the subtitle size data for judging a scrolling information of the second subtitle data.  
         [0020]     Besides, the scrolling subtitle detecting device of the invention further includes a storage unit  10  which provides the subtitle data stream, and a subtitle decoding unit  12  which decodes the subtitle data stream to generate the subtitle size data, the first subtitle data and the second one to the receiving unit  16  and a subtitle frame buffer  14  respectively, and then the first subtitle data and the second one stored in the subtitle frame buffer  14  are forwarded to the receiving unit  16  for detecting by the detecting module  18 .  
         [0021]     With reference to  FIG. 2 , a scrolling subtitle detecting device according to another preferred embodiment of the invention includes the detecting module  18  having a first comparator  180 , which compares blocks of the first subtitle data classified according to the subtitle size data with a subtitle a length parameter and a width parameter with blocks of the second one; a counting unit  182 , which includes a counter and records times of the blocks of the second one equaling to the first one; a second comparator  184 , which compares the counter with a threshold for judging whether the second subtitle data is a scrolling subtitle or not; and a third comparator  186 , which compares a start address of blocks of the first subtitle data with the one of the second subtitle data for obtaining the difference while the second subtitle data is the scrolling subtitle. It&#39;s noted that the start address is the location of blocks of the subtitle data. Moreover, the detecting module  18  judges a scrolling information including the scrolling up, scrolling down, and start address offset of scrolling subtitle according to the difference.  
         [0022]     With reference to  FIG. 3 , a flow chart showing the steps of a scrolling subtitle detecting method according to another preferred embodiment of the invention includes of receiving a subtitle size data, a first subtitle data and the second one in the step S 14 , and obtaining a difference from detecting the first subtitle data and the second one according to the subtitle size data for judging a scrolling information of the second subtitle data in the step S 16 .  
         [0023]     Moreover, the scrolling subtitle detecting method of the invention further includes of decoding a subtitle data stream to generate the subtitle size data, the first subtitle data and the second one in the step S 10 , and then storing the first one and the second one to a subtitle frame buffer in the step S 12  before performing the step S 14 .  
         [0024]     Furthermore, the step S 16  further includes the steps of comparing blocks of the first subtitle data with the second one; providing a counter and accumulating the counter while the blocks of the second one equaling to the first one; comparing the counter with a threshold, and judging the second subtitle data is scrolling while the counter equaling to the threshold; comparing a start address of blocks of the first subtitle data with the one of the second subtitle data for obtaining the difference while the second one is scrolling; and judging a scrolling information of the second subtitle data according to the difference.  
         [0025]     With reference to  FIG. 4 , the detecting module  18  includes a first subtitle data  20  and a second subtitle data  22 , where the length and width of the first subtitle data  20  and the second subtitle data  22  is determined according to a subtitle length parameter and a subtitle width of the subtitle size data. In the embodiment, the first subtitle data  20  includes a first block  200 , a second block  202 , a third block  204 , a fourth block  206  and a fifth block  208 , whereas the second subtitle data  22  includes a first block  220 , a second block  222 , a third block  224  and a fourth block  226 .  
         [0026]     Moreover, since a threshold is equal to four and the counter zero initially in the embodiment, the first comparator  180  of the detecting module  18  compares the first block  200  of the first subtitle data  20  with the first block  220  of the second subtitle data  22 , and then compares the first block  200  with the second block  222 , third block  224  and the fourth block  226  since the first block  200  is not equal to the first block  220  third block  224  and the fourth block  226 . Because of the inequality, the detecting module  18  compares the second block  202  of the first subtitle data  20  with the first block  220  of the second subtitle data  22 . Because of the equality, the counting unit  182  of the detecting module  18  accumulates the counter and the second comparator  184  of the detecting module  18  compares the counter with a threshold, and the comparison result can&#39;t be taken as a judging basis since the counter is less than the threshold at present. The detecting module  18  compares the third block  204  of the first subtitle data  20  with the first block  222  of the second subtitle data  22 , and the rest may be deduced by analogy to conclude that the second subtitle data is a scrolling subtitle. In other words, the counter is equal to the threshold when the third block  204 , the fourth block  206  and the fifth block  208  of the first subtitle data  20  are equal to the second block  222 , the third block  224  and the fourth block  226  of the second subtitle data  22  respectively, and the second subtitle data may be viewed as a scrolling subtitle. Consequently, the third comparator  186  of the detecting module  18  compares a start address of the blocks of the first subtitle data with the one of the second subtitle data for obtaining the difference while the second subtitle data is the scrolling subtitle. The difference is − 1  since the start address of the second block  202  is 2 and the one of the first block  220  is 1, the second subtitle data is scrolling up and the start address offset of scrolling subtitle is 1. By contrast, the second subtitle data is scrolling down while the difference is a positive number.  
         [0027]     With reference to  FIG. 5 , a scrolling subtitle detecting device applying to a digital medium player according to another preferred embodiment of the invention includes a storage unit  24 , which provides an audio and video data stream comprising the subtitle data stream; a data stream separating unit  26 , which separates the subtitle data stream from the audio and video data stream; a subtitle decoding unit  30 , which decodes the subtitle data stream to generate a subtitle size data, a first subtitle data and a second one; a subtitle frame buffer  34 , which stores the first subtitle data and the second one of the subtitle decoding unit  30 ; a receiving unit  36 , which receives the subtitle size data of the subtitle decoding unit  30  and the first subtitle data and the second one of the subtitle frame buffer  34 ; and a detecting module  38 , which detects the first subtitle data and the second one and obtaining a difference for judging a scrolling information of the second one.  
         [0028]     Moreover, the scrolling subtitle detecting device applying to a digital medium player according to another preferred embodiment of the invention further includes an overlapping unit  40 , which overlaps a first video signal, the first subtitle data, a second video signal, the second subtitle data and the scrolling information stored in the detecting module  38  to a display wherein a video decoding unit  28  decodes the video stream to produce the first video signal and the second one and stores them in a video frame buffer  32 .  
         [0029]     Furthermore, the detecting module  38  further includes a first comparator, a counting unit, a second comparator, and a third comparator for performing the functions as described above.  
         [0030]     In addition, the scrolling subtitle detecting device and method of the invention can be embodied through firmware and hardware.  
         [0031]     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.