JPH09219828A - On-screen composite device for digital broadcasting receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform on-screen compositing suitable to the respective kinds of videos by setting a format suitable to a video decoder, performing parallel/ serial conversion, using on-screen switching signals and performing multiplex to program video signals. SOLUTION: An on-screen information generator 191 generates digital Y, CB and CR signals by setting a palette to the format suitable to the video decoder by the software control of a microcomputer 180. Then, a parallel/serial converter 1503 converts the signals to serial Y, CB and CR signals. A digital multiplexer 1504 multiplexes the serial Y, CB and CR signals to the program video signals from the video decoder 140 by using the on-screen switching signals Ym and Ys from the on-screen information generator 191. Thus, the need of a high-speed matrix transformer is eliminated and the on-screen composite suited to the respective kinds of the videos of different output signal formats is made possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-screen synthesizing device for a digital broadcast receiver for displaying on-screen program information and the like.

[0002]

2. Description of the Related Art In recent years, with regard to digital broadcasting, following the start of digital satellite broadcasting in the United States, digital satellite broadcasting plans are progressing in Europe and Asia including Japan. In digital broadcasting, it is usually possible to compress a plurality of programs by digital signal processing and multiplex them into one physical channel, and broadcast over several tens to 100 channels is realized.

Therefore, in order to facilitate the viewer's program selection, the broadcasting station usually sends program information (hereinafter referred to as an electronic program guide) in a multiplexed manner with the program.

On the other hand, the digital broadcast receiver is required to have a function of appropriately presenting the electronic program guide to the viewer.

Conventionally, a digital broadcast receiver is shown in FIG.
It is configured like. FIG. 5 is a block diagram showing the configuration of a standard digital satellite broadcast receiver which is an example of a digital broadcast receiver.

In FIG. 5, 100 is a tuner section,
A desired physical channel is selected from intermediate frequencies from the LNB such as BS and CS.

Reference numeral 110 is a demodulation device, and 120 is an error correction device, which reproduces a digital signal from the selected physical channel. A program extraction / separation device 130 extracts desired programs and program information from a plurality of multiplexed programs. 14
A video signal decoder 0 reproduces a coded and compressed video signal.

An on-screen synthesizer 150 multiplexes desired on-screen information on the video signal of the program.

A voice signal decoder 170 reproduces a coded and compressed voice signal. Reference numeral 160 denotes a video signal encoding device which converts the video signal into a desired signal format NTSC /
Encode to baseband signal in PAL format,
Allows you to connect to a 0 TV monitor. 180 is
A microcomputer controls the system of all parts. An on-screen information generator 190 outputs on-screen information such as an electronic program guide under the control of the microcomputer 180.

Reference numeral 200 denotes an IC card, which performs a combination of an encryption key for descrambling a program, management of viewing charges, and the like. With the above configuration, the program is displayed on the television monitor 2.
10 will be displayed.

Further, the conventional on-screen synthesizing apparatus 1
50 and the on-screen information generator 190 will be described with reference to FIGS. 6 and 7, respectively.

FIG. 6 is a block diagram showing a configuration of a main part of an on-screen synthesizing device 150 of a conventional digital broadcast receiver. The same components as those in FIG. 5 are designated by the same reference numerals,
The description is omitted here.

In FIG. 6, reference numeral 190 is an on-screen information generator, the operation of which will be described with reference to FIG. FIG. 7 is an image diagram showing an example of the internal memory configuration of the on-screen information generator.

As shown in FIG. 7, in the internal memory, a 4-bit palette number corresponding to the number of horizontal dots × the number of vertical dots in one screen. Has a memory that specifies
By reading out this palette designation memory in synchronization with the horizontal and vertical synchronizing signals, the palette number for each dot is determined.
Are sequentially specified. Furthermore, each designated pallet N
O. Will output 4-bit digital data for each of R, G, and B as pixel data indicating a color represented by 4 bits for each of R, G, and B, depending on the contents of the palette table from 0 to 15.

The on-screen synthesizing apparatus 150 will be described with reference to FIG. 6 again. In FIG. 6, reference numeral 1502 denotes a matrix conversion device that converts digital R, G, B signals into digital Y, RY (CR), BY (CB) signals in a ROM.
1512, ROM 1522, and ROM 1532 are used for conversion.

The arithmetic expression in each ROM is, for example, ROM1.
512 is output Y = 0.30 × input R + 0.59 × input G + 0.1
1 × input B, ROM 1522 output CB = −0.30 × input R−0.59 × input G +
0.89 × input B, ROM 1532 outputs CR = 0.70 × input R−0.59 × input G-0.
11 × input B, and performs NTSC system matrix conversion.

Reference numeral 1503 is a parallel-serial conversion device,
Digital Y, RY (CR), BY (CB) signals
Convert to serial Y, RY (CR), BY (CB) signals.

The operation of the parallel / serial conversion device 1503 will be described with reference to FIGS. 8 and 9.

FIG. 8 shows a parallel-serial conversion device 150.
3 is a block diagram showing an example of the internal configuration of No. 3, and FIG. 9 is a timing chart showing its operation. In FIG. 8, 3000,
Reference numerals 3010, 3020 and 3030 denote data flip-flops having a three-state function, and as shown in FIG.
Each signal data of B and CR is output at the rising edge of the 13.5 MHz clock.

A timing generator 2300 generates the YOE, CBOE, and CROE signals shown in FIG. Each signal of YOE, CBOE, and CROE is connected to the 3-state control terminal of each data flip-flop as shown in FIG. 8, and each data flip-flop outputs LowActiv.
Select the output signal by using the output control signal of e.
As shown in FIG. 9, each signal is serially output in the order of CB, Y, CR, and Y.

The on-screen synthesizing device 150 will be described with reference to FIG. 6 again. A digital multiplex device 1504 multiplexes an on-screen signal from the parallel-serial conversion device and a program video signal output from the output of the video decoder 140 by using on-screen switching signals Ym and Ys. In this on-screen switching signal, for example, the Ys signal and the program video signal,
The Ym signal is a switching signal for the on-screen video signal, and the Ym signal is a half-brightness control signal. Then, the output signal of the digital multiplex device 1504 is output to the video signal encoder 160.

The input signal format of the video signal encoder 160 will be described with reference to FIG. FIG. 10 is a signal waveform diagram showing an input signal format of the video signal encoder 160.

As shown in FIG. 10, the color difference signals CB and CR are paired for each luminance signal of 2 dots, are input to the video signal encoder, and are encoded into a desired signal format (NTSC signal format or the like). It is output to the monitor 210, and the on-screen information and the program are multiplexed.

[0024]

However, according to the above configuration, (1) the R, R output from the on-screen information generating device,
The high-speed matrix conversion circuit 1502 in FIG. 6 for converting the G and B signals into the signal format Y, RY, and BY signal formats of the video decoder output in real time is required. When the output signal format is different, each dedicated high-speed matrix conversion circuit is required.

(2) Normally, a digital video encoder has two
Since there is only one color expression capability per dot, the function of the on-screen information generation device having one color expression capability per dot cannot be fully utilized. There were problems such as.

[0026]

In order to achieve the above object, an on-screen synthesizing device for a digital broadcast receiver according to the first invention of the present invention is a digital Y, RY, BY.
On-screen information generation that generates on-screen information that matches the signal format similar to that of the video decoder output by a video decoder that outputs a program video signal of a format and a color palette whose expression format can be switched under the control of a microcomputer, etc. A serial-to-serial converter for serially converting the digital Y, RY, BY signals output from the on-screen information generator, and serial digital Y, RY, output from the video decoder.
It has a configuration of a digital multiplex device that multiplexes the serial digital Y, RY, and BY signals output from the parallel-serial conversion device with the BY signal.

Further, in the embodiment of the second invention, the first
The parallel-serial conversion device having the configuration of the above embodiment is characterized in that the color difference signals selected for every two dots can be switched at high speed.

According to the present invention, the on-screen synthesizing device for a digital broadcast receiver is provided with the following advantages: (1) Low cost because a dedicated high-speed matrix conversion circuit is not required even for video decoders having different output signal formats. 2) High-performance on-screen synthesis that fully utilizes the functions of the on-screen information generator capable of expressing one color per dot is realized.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION The on-screen synthesizing apparatus for a digital broadcasting receiver according to the first and second aspects of the present invention restores digital compression coded image data to obtain a digital luminance signal Y and a digital color difference signal R. -Y and BY output video decoding device and color palette such as 3 primary color format, luminance color difference signal format, etc. An on-screen information generator for generating on-screen information according to a signal format, and parallel digital Y, RY, B- output from the on-screen information generator.
A parallel / serial conversion device for converting a signal such as Y into a serial signal format, a digital multiplex device for multiplexing the output of the parallel / serial conversion device on a digital video signal output from the video decoding device, and a digital multiplex device Output digital Y, R
And a digital video encoding device for converting the -Y and BY signals into an analog composite video signal or an analog Y / C signal.

The on-screen information generator changes the output format of the on-screen information signal by changing only the color expression format of the color palette so that the signal format of the on-screen information signal matches the output signal format of the video decoding apparatus. It is characterized by performing on-screen synthesis into a program for different video decoding devices without using a matrix conversion device, etc., and the signal format output from the on-screen information generation device is hardware. It is possible to easily adapt to the output signal format of the video decoding device without changing the above, and it is possible to realize inexpensive on-screen synthesis that does not require a high-speed matrix conversion circuit.

Next, a third invention of the present invention is the parallel digital conversion device of the first invention, wherein the parallel digital Y, RY, B- output from the on-screen information generating device.
Which one of the two-dot luminance signals corresponds to the one-dot color-difference signal that is selectively output with respect to the two-dot luminance signal when a serial digital video signal is generated from signals such as Y Is configured so that it can be arbitrarily switched in units of 2 dots by a control signal. In the parallel-serial conversion device, the color difference signal selected for every 2 dots can be switched at high speed, so This has the effect of enabling on-screen composition by making full use of the function of the on-screen information generating device capable of expressing one color.

(First Embodiment) An example of the first and second embodiments of the present invention will be described below with reference to FIG.

FIG. 1 is a block diagram showing the configuration of the main part of the on-screen synthesizing apparatus for a digital broadcast receiver in this embodiment. The description of the configuration and common parts of the conventional device shown in FIG. 6 is omitted, but FIG. 1 is characterized in that the high-speed matrix conversion device is not necessary as compared with FIG. 6 of the conventional example.

In FIG. 1, reference numeral 191 is an on-screen information generator, and its operation will be described here with reference to FIG. FIG. 2 is an image diagram showing an example of the internal memory configuration of the on-screen information generator. As shown in FIG. 2, the internal memory has a memory for designating a 4-bit palette number corresponding to the number of horizontal dots × the number of vertical dots of one screen, as in the conventional example, and this palette is designated by an internal counter. By reading the memory in synchronization with the horizontal and vertical synchronizing signals, the pallet number for each dot is sequentially specified. However, here pallet number 0
The color designation method of each palette of 15 is characterized in that it can be set to an arbitrary format by microcomputer control by software control by a microcomputer or the like.

In this way, by setting the palette in the format suitable for the video decoder, in this example, each of the four Y, RY (CR) and BY (CB) formats is set. Bit digital data will be output. Although not shown in this example, bit allocation, for example, 6 bits for Y signal, CB, C
It is also possible to arbitrarily set the palette format including bit allocation such as 3 bits for each R signal.

The on-screen synthesizing device will be described again with reference to FIG. Reference numeral 1503 denotes a parallel-serial conversion device, which is digital Y, RY (CR), BY (C).
B) signal to serial Y, RY (CR), BY (C
B) Convert to a signal. Since the operation is similar to the conventional example, the description of the internal operation is omitted here.

Reference numeral 1504 denotes a digital multiplex device which multiplexes serial format digital Y, RY and BY signals into a program video signal using on-screen switching signals Ym and Ys.

In this on-screen switching signal, for example, the Ys signal is a switching signal between the program video signal and the on-screen video signal, as in the conventional example. In the digital multiplexer 1504, the Ys signal causes the program video signal to be switched to the program video signal. , Switch to the on-screen video signal.
On the other hand, the Ym signal is a half-brightness control signal, and in the digital multiplex device 1504, the Ym signal changes the brightness level of the program video signal.

As described above, by constructing the on-screen synthesizing device of the present invention, the high-speed matrix conversion device as in the conventional example is unnecessary, and the inexpensive on-screen suitable for various video decoders having different output signal formats. Synthesis is possible.

(Second Embodiment) An example of a third embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is a block diagram showing the construction of the main part of a parallel-serial conversion apparatus which constitutes the on-screen synthesizing apparatus for the digital broadcast receiver according to the second invention.
FIG. 3 is a timing waveform chart showing the operation. Figure 6 above
The description of the configuration and common parts of the conventional device shown in FIG.

2000, 2010, 2020, 2030
Is a data flip-flop, and as shown in FIG.
Each signal data of B and CR is output at the rising edge of the 13.5 MHz clock. 2300 is a timing generator similar to that of the conventional example, and has the YOE and CBO shown in FIG.
Each of the E and CROE signals is generated.

Reference numerals 2100, 2110, and 2120 are AND devices, which use the YOE, CBOE, and CROE signals to
Gate control of Y, CB, and CR signals is performed. 2200
Is an OR device with three inputs, 2400, 2410
Is a changeover switch controlled by the YEF signal.

This YEF signal is a signal defined for the first time here and is a 1-bit signal controlled by a microcomputer or the like. The operation of the on-screen synthesizing device including the YEF signal will be described below.

First, when the YEF signal is inactive, the switches 2400 and 2410 are in the positions shown by the solid lines in the figure, and the data flip-flops 2000, 2010 and 20 are shown.
The 30 outputs are output as shown in FIG. At this time,
In the logical product devices 2100, 2110, 2120, YO
The respective control signals of E, CBOE, and CROE are gate-controlled in the Low period as shown in FIG.
Is output via. Up to this point, the operation is the same as that of the parallel-serial conversion device of the conventional example.
For the two dots of Y2, the color difference signals CB1 and CR1 corresponding to the leading Y1 are output as shown in the figure.

Next, when the YEF signal becomes active,
The switches 2400 and 2410 are switched to the positions shown by the dotted lines in the figure. At this time, the D input signal of the data flip-flop 2110 is input to the changeover switch 2400, and the data flip-flop 202 is input to the changeover switch 2410.
0 output is input. As a result, the CBOE and CROE signals output from the timing generator select the color difference signals CB4 and CR4, respectively, as shown in FIG.
Color difference signals CB4 and CR4 corresponding to 4 are output as shown in the figure.

Next, when the YEF signal becomes inactive again, the switches 2400 and 2410 are in the positions shown by the solid lines in the figure, and like the conventional example, the two dots of the luminance signals Y5 and Y6 correspond to the leading Y5. Color difference signal, CB5, CR5
Is output as shown in the figure. By switching the YEF signal, for example, at a cycle of several frames, it is possible to switch colors colored in units of 2 dots periodically.
A new expression effect such as marking of the cursor by changing the color becomes possible.

With the above configuration, the color difference signals selected for every 2 dots by the 1-bit signal YEF can be switched at high speed, and therefore, the on-screen information having the expression ability of 1 color per dot can be obtained. On-screen synthesis that makes use of the function of the generator as a new expression effect is possible.

[0049]

As described above, according to the present invention, the conventional high-speed matrix conversion device is not required, and inexpensive on-screen synthesis suitable for various video decoders having different output signal formats is possible. Further, the function of the on-screen information generation device having the ability to express one color per dot in the related art can be utilized as a new expression effect even in a digital broadcast receiver to enable on-screen composition.

As described above, a low-cost, high-quality digital broadcast receiver can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a main part of an on-screen synthesis device for a digital broadcast receiver according to a first embodiment of the present invention.

FIG. 2 is a memory image diagram showing an example of the internal memory configuration of the on-screen information generator according to the first and second embodiments of the present invention.

FIG. 3 is a block diagram showing a configuration of a parallel-serial conversion device according to a second embodiment of the present invention.

FIG. 4 is a timing chart showing the operation of the parallel-serial conversion device according to the second embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a conventional digital broadcast receiver.

FIG. 6 is a block diagram showing a configuration of a conventional on-screen synthesis device.

FIG. 7 is a memory image diagram showing an example of a memory configuration inside a conventional on-screen information generator.

FIG. 8 is a block diagram showing a configuration of a conventional parallel-serial conversion device.

FIG. 9 is a timing chart showing the operation of a conventional parallel-serial conversion device.

FIG. 10 is a signal waveform diagram showing an input signal format of a digital video encoding device in a digital broadcast receiver.

[Explanation of symbols]

 140 video decoding device 151 on-screen synthesizing device 160 digital video encoder 191 on-screen information generating device 1503 parallel-to-serial converting device 1504 digital multiplexing device

Claims (3)

[Claims] 1. An on-screen information generating device for outputting a signal format suitable for an output signal format of a video decoding device for restoring digital compression-encoded image data can arbitrarily select a color expression format suitable for the output signal format. An on-screen synthesizing device for a digital broadcast receiver, comprising a switchable color palette and performing on-screen synthesizing the output signal of the on-screen information generating device with the output signal of the video decoding device. 2. A digital signal format comprising a video decoding apparatus for restoring digital compression-coded image data to output a digital luminance signal and a digital color difference signal, and a color palette capable of arbitrarily switching color expression formats. An on-screen information generating device for generating on-screen information by means of the above, a parallel-serial conversion device for converting a parallel digital signal output from the on-screen information generating device into a serial signal format, and a digital image output from the video decoding device. A digital multiplex device that multiplexes the output of the parallel-serial conversion device with a signal, and a digital video encoding device that converts a digital signal output from the digital multiplex device into an analog composite video signal or an analog Y / C signal are provided. That An on-screen synthesizer for digital broadcast receivers. 3. When the parallel-serial conversion device generates a serial digital video signal from the parallel digital signal output from the on-screen information generating device, 2
A configuration in which a color difference signal corresponding to one of the two dot luminance signals that is selectively output as a color difference signal for the dot luminance signal can be arbitrarily switched in 2-dot units by a control signal. The on-screen synthesizing device for a digital broadcast receiver according to claim 1.