KR100845833B1 - Caption data processing device of digital TV - Google Patents

Abstract

The present invention is to implement the functions necessary for processing digital caption broadcasting data. That is, to implement a graphic processing system that satisfies the digital caption broadcasting processing regulations set by the FCC, the MPEG-2 video processing unit for extracting and processing the screen control code and text information from the digital broadcast signal, and the MPEG-2 video It comprises a DTVCC decoder that generates graphic data (bitmap font) from the text information extracted by the processing unit, and applies the font border effects to the generated bitmap data to output to the screen in OSD form. have.

Set-top boxes, font post-processing, digital closed caption receivers

Description

Apparatus for processing caption data in digital TV}

1 is a block diagram of an audio processing system of a digital broadcast receiving set top box according to the present invention.

2 shows a font post-processor (FPP) as one of the greatest features of the present invention.

3 is a flowchart illustrating a detailed operation of the frame search / filter unit according to the present invention.

4 is a flowchart illustrating the detailed operation of the boundary filter according to the present invention.

5 is a flowchart illustrating a detailed operation of a shadow filter according to the present invention.

* Explanation of symbols for main parts of the drawings

100: DTVCC decoder 110: DTVCC extractor

120: bitmap font generator 130: font post-processor

131: font buffer 132: first filter selector

133: border search / filter section 134: second filter selector

135: boundary filter 136: shadow filter

140: instruction processing unit 150: caption screen controller

200: MPEG-2 video processor 210: MPEG demux                 

220: video extractor 230: MPEG-2 decoder

240: video synthesizer 250: system information extractor

260: UI processing unit

The present invention relates to a graphic processing technique of text data for digital closed caption data representation in a digital broadcast receiver.

Recently, as digital broadcasting has been implemented in North America and Europe, development of TVs and dedicated receivers (Set-Top Box: STB) capable of receiving them has been actively developed.

Closed caption broadcasting is a broadcast that allows a hearing-impaired person to watch TV on a level equivalent to that of the general public by transmitting a code representing voice and sound in a video signal.

Currently, closed caption processing is an essential requirement for analog and digital broadcast receivers in North America and Europe. (Analog Standard: EIA-608B, Digital Standard: EIA-708B, Digital Standard after July 1, 2002) ).

In general, the caption signal transmitted together with the video signal is separated from the video signal in the receiving apparatus and then superimposed on the video signal using an OSD (On Screen Display).

In the conventional analog broadcasting receiver, the analog caption data in the NTSC video signal VBI section 21 line is processed by the integrated circuit or software module built in the receiver. In the digital broadcasting receiver, the receiver equipped with the digital caption signal processing function Not yet.

According to the US FCC, since July 1, 2002, digital broadcasting receivers manufactured or sold in North America have been mandated to process digital subtitle broadcasting data.

In particular, the digital caption broadcasting standard defines font border effects for realizing caption broadcasting that is compatible with digital broadcasting and for improving the quality of viewing of the broadcast for the hearing impaired.

The character boundary effect refers to giving a character a border color, a three-dimensional effect, a shadow effect, etc., rather than a plain plain character.

Therefore, the necessity of embodying the above effects of characters as well as extraction and control of digital subtitle data has emerged.

Accordingly, the present invention is to implement the functions necessary for processing the digital subtitle broadcast data described above to solve the above problems. That is, the object of the present invention is to implement a graphics processing system that satisfies the digital caption broadcasting processing regulations set by the FCC.

Features of the caption data processing apparatus of the DTV according to the present invention for achieving the above object is an MPEG-2 video processing unit for extracting and processing the screen control code and text information from the digital broadcast signal, and the MPEG-2 video processing unit And a DTVCC decoder which generates graphic data (bitmap font) from the extracted text information and applies font border effects to the generated bitmap data and outputs it on the screen in OSD form. .

At this time, the DTVCC decoder unit and the DTVCC extractor for decomposing the digital subtitle packet data in the user-data area of the received MPEG-2 video, separated into a caption command and caption text; A command processing unit that performs a necessary function or procedure according to the caption command separated by the DTVCC extractor, a bitmap font generator that generates font data in bitmap form according to input of the caption text separated by the DTVCC extractor, and the bit A post-processing font for giving special effects such as borders, three-dimensional effects, and shadows to the edges of the bitmap font data generated by the map font generator, and a bitmap font post-processed according to the caption command processed by the command processor And a caption screen controller that controls the display of data on the screen. There are other features.

In this case, the font post-processor may select a necessary filter by referring to a font buffer temporarily storing the bitmap format font data generated by the bitmap font generator and a caption command for the font output from the command processor. A filter selector, a border search / filter unit selected from the filter selector, searching for bitmap fonts to find a border, and giving a color for a caption command, and selected from the filter selector, the border search A border filter which processes a border to have a three-dimensional effect on a border provided by the filter unit, or gives a stereo effect to a bitmap font stored in the font buffer, and is selected from the filter selector, wherein the border search / Searches in the filter section to add a shadow effect to the colored border or to save the font buffer. Is composed, including a bitmap shadow filter (shadow filter) to give a shadow effect in the font has a further feature.

In this case, the MPEG-2 video processor is an MPEG demux for extracting video and system information from the received MPEG-2 transport stream, a video extractor for extracting MPEG-2 video data from the MPEG demux, the video extractor MPEG-2 decoder that extracts a picture from MPEG-2 video data extracted from and decodes it for display on a TV screen, and a system information extractor that extracts program information from system information extracted from the MPEG demux. a system information parser), a UI processing unit for converting the program information extracted by the system information extractor 250 into a GUI form through user selection, a GUI signal output from the UI processing unit, and the MPEG-2 decoder 230 Synthesizes the video decoded by the caption OSD and the bitmap font data post-processed by the DTVCC decoder. It is configured to include a video combiner (video combiner) for outputting a video signal by combining the picture is another feature.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

A preferred embodiment of the caption data processing apparatus of the DTV according to the present invention will be described with reference to the accompanying drawings.

1 shows a block diagram of an audio processing system of a digital broadcast reception set-top box according to the present invention.

Referring to FIG. 1, the DTVCC decoder 100 and the MPEG-2 video processor 200 including a graphic processing system (GRPS) may be divided into two parts.

In this case, the DTVCC decoder 100 includes a DTVCC extractor 110, a command processor 140, a bitmap font generator 120, and a font post-processor. Font Post Processor (FPP) 130 and a caption screen controller 150.

The MPEG-2 video processor 200 includes an MPEG-2 demux 210, an MPEG-2 decoder 230, a system information parser 250, and a video combiner. It consists of 240.

Referring to Figure 1 in more detail as follows.

First, the DTVCC decoder 100 decomposes the digital subtitle packet data in the user-data area of the received MPEG-2 video to separate the caption command and the caption text. A bit according to the input of the caption text separated from the DTVCC extractor 110, the command processor 140 performing a necessary function or procedure according to the caption command separated from the DTVCC extractor 110, and the DTVCC extractor 110. The bitmap font generator 120 for generating font data in a map format, and post-processing to give special effects such as a border, a three-dimensional effect, and a shadow to the edges of the bitmap font data generated by the bitmap font generator 120 A caption screen for controlling to display a post-processed bitmap font data according to a caption command processed by the command processor 140 and the font post-processor 130 on the screen. It consists of a controller 150.

In this case, the bitmap font generator 120 used an outline font generation engine to satisfy the regulations of the Federal Communications Commission (FCC) for freely adjusting the font size.

Next, the MPEG-2 video processor 200 extracts MPEG-2 video data from the received MPEG-2 transport stream and MPEG-2 video data from the MPEG demux 210. A video extractor 220 for extracting, an MPEG-2 decoder 230 for extracting a picture from the MPEG-2 video data extracted by the video extractor 220, and decoding the picture for display on a TV screen; A system information parser 250 for extracting program information from the system information extracted by the MPEG demux 210, the video decoded by the MPEG-2 decoder 230, and the system information extractor 250. A video combiner for synthesizing the extracted GUI and the caption OSD, which is the bitmap font data post-processed by the DTVCC decoder 100, to synthesize a single picture and to output a video signal. It consists of 240.

In this case, a UI processor 260 is configured to process the program information extracted by the system information extractor 250 as a GUI signal through an external input of a user and output the GUI information to the video synthesizer 240.

2 shows a font post-processor (FPP), one of the greatest features of the present invention.

Referring to FIG. 2, first, a font buffer 131 for temporarily storing bitmap-type font data generated by the bitmap font generator 120 and a caption command for a font output from the command processor 140 are referred to. A first filter selector 132 for selecting a required filter and a first filter selector 132, first searching for a bitmap font to find a border, and then assigning a color to the caption command. The border search / filter unit 133 and the second filter selector 134 and the border search / filter unit 133 searched by the border search / filter unit 133 to give a three-dimensional effect are processed, or A border filter 135 for giving a stereoscopic effect to the bitmap fonts stored in the font buffer 131 through the first filter selector 132, and the second filter selector 134. To 133 A shadow filter 136 that adds a shadow effect to the searched and colored border or a shadow effect is applied to a bitmap font selected by the first filter selector 132 and stored in the font buffer 131. It is composed of

Accordingly, the font output from the font post-processor 130 outputs at least one of a border color font, a border or border + boundary font, and a shadow or border + shadow font.

The font post-processor (FPP) 130 configured as described above selects the filter selector based on the caption command from the edge search / filter unit, the boundary filter, and the shadow filters described above, thereby making the font border, three-dimensional and shadow effects. Will produce a complex font of.

3, 4, and 5 show an implementation algorithm of each filter described above in a flowchart.

3 is a flowchart illustrating the detailed operation of the frame search / filter unit according to the present invention.

Referring to FIG. 3, first, a bitmap font generator 120 stores a bitmap font in a font buffer 131 to which a border color is to be assigned among font data of a bitmap format (S1).

Subsequently, the filter selector 132 selects the edge search / filter unit 133 with reference to the caption command for the font output from the command processor 140 (S2).

The frame search / filter unit 133 selects an arbitrary pixel from the bitmap fonts stored in the font buffer 131 and sets it as a reference pixel (S3).

Subsequently, it is determined whether the set reference pixel has meaningful data other than null (S4).

As a result of the determination, when there is meaningful data that is not null, eight pixels are displayed around the reference pixel with a defined border color (S5).

Subsequently, the process is repeated by setting all pixels of the bitmap font as reference pixels (S6).

When the border color is set in the corresponding pixels of all the bitmap fonts as described above, the original bitmap font is displayed again on the bitmap font filled with the border color (S7).

This is a relatively simple algorithm that is excellent in terms of speed and simplicity.

4 is a flowchart showing the detailed operation of the boundary filter according to the present invention.

Referring to FIG. 4, first, the bitmap font generator 120 stores a bitmap font in the font buffer 131 to give a stereoscopic effect among font data in a bitmap format (S8).

Subsequently, the filter selector 132 selects the boundary filter 135 with reference to the caption command for the font output from the command processor 140 (S9).

The boundary filter 135 selects an arbitrary pixel from the bitmap fonts stored in the font buffer 131 and sets it as a reference pixel (S10).

Subsequently, it is determined whether the set reference pixel provides a three-dimensional effect of a raised edge or a three-dimensional effect of a depressed edge (S11).

As a result of the determination, when the reference pixel provides the concave stereoscopic effect, the pixel is moved to 1 pixel to the left and 1 pixel to the left to display the pixel slightly lighter than the original font color (S12).

As a result of the determination, when the reference pixel imparts a convex stereoscopic effect, the reference pixel is moved one pixel to the right and one pixel downward to display the pixel slightly darker than the original font color (S13).

Subsequently, the process is repeated by setting all pixels of the bitmap font as reference pixels (S14).                     

When the stereoscopic effect is set on the corresponding pixels of all the bitmap fonts as described above, the original bitmap font is displayed again on the bitmap font to which the stereoscopic effect is applied (S15).

This method is also a relatively simple algorithm, which is excellent in terms of speed and simplicity.

5 is a flowchart showing the detailed operation of the shadow filter according to the present invention.

Referring to FIG. 5, first, the bitmap font generator 120 stores a bitmap font in a font buffer 131 to which a shadow effect is to be applied among font data of a bitmap format (S16).

Subsequently, the filter selector 132 selects the shadow filter 136 with reference to the caption command for the font output from the command processor 140 (S17).

The shadow filter 135 selects an arbitrary pixel from the bitmap fonts stored in the font buffer 131 and sets it as a reference pixel (S18).

Subsequently, it is determined whether the set reference pixel is to give a right shadowed-border or a left shadowed-border (S19).

As a result of the determination, when the reference pixel gives the rightward shadow effect, the pixel is displayed in black by moving 2 pixels to the right and 2 pixels downward from the reference pixel (S20).

As a result of the determination, when the reference pixel gives the leftward shadow effect, the pixel is displayed in black by moving 2 pixels to the left and 2 pixels downward from the reference pixel (S21).

Subsequently, the process is repeated by setting all pixels of the bitmap font as reference pixels (S22).

When the shadow effect is set on the corresponding pixels of all the bitmap fonts as described above, the original bitmap font is displayed again on the bitmap font to which the three-dimensional effect is applied (S23).

This method is also a relatively simple algorithm, which is excellent in terms of speed and simplicity.

As described above, the present invention is a graphic processing technology required for displaying digital subtitle data in a digital TV stream in the form of an OSD, and all digital TV awards produced or sold after the time limit set by the US FCC (July 1, 2002) are required. It can be applied to devices or set-top boxes.

The caption data processing apparatus of the DTV according to the present invention as described above can not only extract and control digital caption data, but also enhance the viewing efficiency of characters, and display digital caption data in a digital TV stream on the screen in OSD form. This graphics processing technology can be applied to any digital TV set or set-top box produced or sold after the US FCC deadline (July 1, 2002).

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

Claims (4)

An MPEG-2 video processor for extracting screen control codes and text information from digital broadcast signals and processing the same; A bitmap font is generated from the text information extracted by the MPEG-2 video processor, and all pixels of the bitmap font are sequentially set as reference pixels to apply at least one of a border color, a stereoscopic effect, and a shadow effect to the pixels. After that, the caption data processing apparatus of the DTV, characterized in that it comprises a DTVCC decoder unit for outputting in the form of OSD on the screen. The method of claim 1, wherein the DTVCC decoder unit A DTVCC extractor that decomposes the digital subtitle packet data in the user-data region of the received MPEG-2 video into a caption command and caption text; A command processor for performing a necessary function or procedure according to the caption command separated by the DTVCC extractor; A bitmap font generator configured to generate bitmap-type font data according to input of the caption text separated by the DTVCC extractor; A font post-processor for post-processing the edge of the bitmap font data generated by the bitmap font generator to give a special effect such as a border, a three-dimensional effect, and a shadow; And a caption screen controller configured to control to display the post-processed bitmap font data on the screen according to the caption command processed by the command processing unit. The method of claim 2, wherein the bitmap font generator is A caption data processing apparatus of a DTV, characterized by using an outline font generation engine to satisfy the regulations of the Federal Communications Commission (FCC) for freely adjusting the font size. The method of claim 1, wherein the MPEG-2 video processing unit MPEG demux that extracts video and system information from the received MPEG-2 transport stream, A video extractor for extracting MPEG-2 video data from the MPEG demux; An MPEG-2 decoder for extracting a picture from the MPEG-2 video data extracted by the video extractor and decoding the picture for display on a TV screen; A system information parser for extracting program information from the system information extracted from the MPEG demux, A UI processing unit for converting the program information extracted by the system information extractor 250 into a GUI form through a user's selection; A GUI signal output from the UI processor, a video decoded by the MPEG-2 decoder 230, and a caption OSD, which is bitmap font data post-processed by the DTVCC decoder, are synthesized into one picture to output a video signal. Caption data processing apparatus for a DTV comprising a video combiner.

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