JP3164728B2 - Automatic caption display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to subtitle processing in video signal processing using the letterbox system.

[0002]

2. Description of the Related Art Television broadcasting and package media use images whose aspect ratio corresponds to the screen of a movie. When a subtitle supermarket such as a movie is displayed outside the video, it is necessary to display the subtitle supermarket during the video period.

The conventional system will be described below with reference to FIG.
FIG. 8 shows the timing of the letterbox period and the subtitle period of one frame. To change the position of the subtitle,
After the user confirms the position of the supermarket, the remote control or the like memorizes the timings T4 and T5 of the subtitle position outside the video, and then stores the timings T7 and T8 in the video screen to move the subtitle.

[0004]

However, in the conventional method as described above, since the position of the subtitle may be different due to the difference in the image media, the user must update the data writing to the memory each time. Had the problem of having to do so.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides an automatic subtitle display device for automatically detecting the position of a subtitle superimposed outside a video and displaying the subtitle superimposed at an arbitrary position within a video screen set in advance. The purpose is to provide.

[0006]

In order to solve the above-mentioned problems, an automatic subtitle display device of the present invention receives a video signal of a letterbox system, and determines whether or not there is a video signal level for each line. The output of the line video determining means and the output of the line video determining means are correlated over N (N is a natural number) frames, and the presence or absence of the correlation of the video signal level within the frame is determined, so that the letterbox period, the subtitle signal multiplexing period and the effective video are determined. a frame image determining means for detecting the signal period, one receives the output of the frame image determining means
After determining the degree , the input of the same data is held for a certain period, and the holding signal of the input same data is output.
A frame image determination holding means for force, the frame in accordance with the output of the video determination holding means takes in the effective video signal and caption signal of the video signal of the letter box system in the memory, the frame image caption signal in the output And memory control means for outputting data in a predetermined period within the period of the effective image with reference to the output timing of the judgment and holding means.

[0007]

[0008]

With the above arrangement, the presence / absence of an image is detected for each line by the line image judging means, and when there is an effective image or a caption super, the amplitude of the luminance signal exceeds a certain level. If it is longer than the set period, it is determined that there is an effective video or a subtitle supermarket. Further, when the output of the line image judging means is correlated over N frames by the frame image judging means, the correlation is obtained in the upper and lower letterbox periods, and the correlation is not obtained in the video signal and the subtitle super period. To detect and output the period timing of video and subtitles. The memory control means writes the video signal and caption data to the memory in accordance with the output timing signal of the frame video determination means, and reads out the address data of the memory in which the caption data is written for a preset period at the time of output. The subtitle can be displayed at an arbitrary position set in advance.

Further, when the processing for correlating the output of the line image judging means is continuously performed over N frames, an image having a very low luminance signal level is continuously generated within the image period at the boundary between the effective image period and the upper and lower letterbox periods. However, there is a difference in the result of the correlation between the case where there is a long period of time and the case where the level is high, and as a result, the position of the subtitle display is shifted every N frames. Is provided after the frame image determination means, the subtitles can be displayed more stably.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an automatic subtitle display device of the present invention will be described with reference to the drawings. FIG. 1 is an automatic caption table of the present invention.
It is an explanatory view of a display device. In FIG. 1, 1 is a video signal 1
1, a line image determining means for detecting presence / absence of an image in a line and outputting a line image determining signal 12, a correlation between N lines of the line image determining signal 12 over N frames, and Frame video determining means for determining presence / absence and outputting a frame video determination signal 22;
Reference numeral denotes a memory control unit that writes a video signal and caption data to a memory in accordance with the timing of the frame video determination signal 22, and outputs a video signal 32 in which caption data is read out during a preset period at the time of output.

The operation of the automatic subtitle display device configured as described above will be described with reference to FIGS. 2, 3, 6, and 7. FIG. FIG. 2 is a block diagram showing a detailed configuration of the line video judging means 1. In FIG. 2, reference numeral 5 compares the brightness signal level of the video signal 11 with the set brightness level 51, and outputs a high-level comparison output 52 if the video signal 11 is larger than the set brightness level 51 and outputs a low-level comparison output 52 if the video signal 11 is smaller than the set brightness level 51. A level comparison circuit 6 is a counter circuit that counts with an in-line sample clock 61 and outputs a count output 62 while the comparison output 52 is at a high level.
Outputs a line video determination signal 12 obtained as a result of comparing the luminance signal level of the input video signal 11 with the set level in one line period, that is, comparing the magnitude of the count output 62 with the period setting data 71. Period comparison circuit 7
It is.

FIG. 3 is a block diagram showing a detailed configuration of the frame video judging means 2. 9 is a line image determination signal 12
The shift register 10 holds data in field units at each line cycle timing and outputs field data 92. The shift register 10 switches the field data 92 for each frame in order to convert the field data 92 to data in frame units. Output selection circuit, 1
Reference numeral 1 denotes a correlation circuit that correlates the frame data 102 over N (N is a natural number) and outputs a frame video determination signal 22.

When the video signal 11 shown in FIG. 6 is input, the level comparison circuit 5 of the line video judging means 1 makes a comparison with a set luminance level 51, and a comparison output 52 is output as shown in the figure. . In the counter circuit 6, while the comparison output 52 is at the high level, it is counted up by the sample clock 61. Based on this output and the period setting data 71, it is determined whether or not the luminance signal has exceeded the set luminance level 51, and a line video determination signal 12, which is information on the presence or absence of an effective video, is output. Here, the period setting data 71 is for preventing a malfunction when the luminance exceeds the set luminance level 51 due to noise.

In the frame image judging means 2, the output of the line image judging means 1 is stored for each field by the shift register 9 for each field, and switched by the selecting circuit 10 for each frame to obtain frame data 102 as shown in FIG. . The correlation circuit 11 correlates the frame data 102 over N frames and outputs a frame video determination signal 22 as shown in the figure. Here, the respective timings of the video period, the subtitle period, and the letter box can be detected.

The memory control means 3 writes the video signal and caption data in the memory by the frame video determination signal 22, and converts the caption data at a preset timing within the video period with reference to the boundary between the video period and the letterbox period. The subtitle can be moved by reading.

As described above, by using the line video determining means and the frame video determining means for determining the presence / absence of video during the line video period and the presence / absence of video over the N-frame period, captions which are automatically displayed outside the video can be displayed. It can be displayed within any video period.

Next, the automatic caption display device of the present invention will be described. Figure 4 shows the structure of an automatic caption display device of the present invention, the difference between FIG. 1 is a point in which a frame image-size Teiho lifting means 4 to the subsequent frame image determining unit 2, others same as FIG. 1 It is.

[0018] FIG. 5 is a detailed block diagram of a frame picture-size Teiho lifting means 4. After holding the frame video determination signal 22 of the frame video determination means 2 from the terminal a through the selection circuit 13 in the shift register 14 for one frame, the selection circuit 13 is switched to the terminal b by the switching signal 131, so that the letter A video having a very low luminance signal level or a video of a normal level at the boundary between the box period and the video period is input, and the frame video determination signal 2
Even if the timing of step 2 is shifted, if the correlation between the N frame periods in the frame video judging means 2 is taken over a sufficient period, the subtitle position can be stably displayed without being shifted accordingly.

[0019]

As described above, according to the present invention, a line video judging means for inputting a letterbox video signal and judging the presence or absence of a video signal level for each line, and an output of the line video judging means. Is correlated over N (N is a natural number) frames, and the video signal level within the frame is
Frame video determination means for detecting a letterbox period, a subtitle signal multiplexing period, and an effective video signal period by determining the presence or absence of a correlation, and the output of the frame video determination means is input, and once the determination is made, the same data is determined. The input is held for a certain period of time, and the same input data is stored.
Frame video determination and holding means for outputting a holding signal, and taking in the effective video signal and the subtitle signal of the letterbox video signal into a memory according to the output of the frame video determination and holding means, and outputting the subtitle signal at the time of output. Automatically detects the video period and the subtitle period of the input video signal by providing a memory control unit that outputs during a preset period of the effective video period based on the output timing of the frame video determination holding unit. However, the subtitle can be set at an arbitrary position within the video period.

Further, by providing the frame image judgment holding means , images having extremely low luminance levels of the image signal at the boundary between the letterbox period and the image period continue, and even if the timing of the boundary is shifted, the frame image judgment is maintained. By holding the data after the length of the frame correlation is sufficiently obtained by the means, the caption can be stably displayed at a position sufficiently coincident with the video period.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an automatic caption display device .

FIG. 2 is a block diagram showing a detailed configuration of a line image determination unit in FIG . 1;

FIG. 3 is a block diagram showing a detailed configuration of a frame video determination unit in FIG . 1 ;

Block diagram showing the whole of the automatic caption display device of the present invention; FIG

Block diagram showing a detailed configuration of a frame image determination holding means in automatic caption display device of the present invention; FIG

FIG. 6 is a waveform chart for explaining a relationship between an input video signal and determination by a line video determination unit.

FIG. 7 is a waveform chart for explaining a determination relationship of a frame video determination unit.

FIG. 8 is a video frame diagram for explaining a conventional subtitle position setting timing relationship.

[Explanation of symbols]

 1 line image judgment means 2 frame image judgment means 3 memory control means 4 frame image judgment holding means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-162751 (JP, A) JP-A-2-305190 (JP, A) JP-A-5-199462 (JP, A) JP-A-5-199462 316444 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H04N 5/278 H04N 5/445

Claims (1)

(57) [Claims] 1. A video signal of a letterbox system is input, and a line video determining means for determining the presence or absence of a video signal level for each line, and an output of the line video determining means is correlated over N (N is a natural number) frames. Frame video determining means for detecting a letterbox period, a subtitle signal multiplexing period, and an effective video signal period by determining whether or not there is a correlation between video signal levels in a frame, and an output of the frame video determining means as an input. Once judge
After dropping, the same data is held for a certain period of time to hold an input, and a frame video judgment holding means for outputting a holding signal of the same input data, and the letterbox method of the letter box method according to the output of the frame video judgment holding means A memory that captures an effective video signal and a subtitle signal of a video signal into a memory, and outputs a subtitle signal during a preset period in a period of an effective video with reference to an output timing of the frame video determination holding unit at the time of output. An automatic caption display device comprising a control unit.