KR100189541B1 - Digital image signal processing apparatus and method - Google Patents

Abstract

1. FIELD OF THE INVENTION The invention described in the claims belongs to a digital video signal processing apparatus and method thereof.

2. The technical problem to be solved by the invention: Provide a digital video signal processing apparatus suitable for digital logic.

3. Summary of the Invention A digital video signal processing apparatus according to the present invention comprises: first means for inserting a composite synchronous signal into a luminance signal; Second means for providing a mixed and limited final composite video signal to a luminance signal output stage; Third means for receiving an input signal and various control signals to perform color modulation; And fourth means for selectively converting the color difference signals into a binary complement signal.

4. Significant use of the invention: for use in digital video signal processing devices.

Description

Digital video signal processing device and method

1 is a circuit block diagram of a conventional digital image signal processing apparatus.

2 is a circuit diagram of a digital image signal processing apparatus according to an embodiment of the present invention.

3 and 4 are concrete circuit diagrams of the mixer 200 and the color modulator 300 of FIG. 2, respectively.

5 is an operation timing diagram of signals used and output in FIG.

6 is an operation table diagram related to a modulation operation of the color modulator 300 of FIG.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal processing apparatus, and more particularly, to a digital video signal processing apparatus and a method thereof capable of properly processing and outputting a received digital composite video signal according to a desired function selection.

The conventional video signal processing apparatus receives analog inputs Y, R-Y, and B-Y, as shown in FIG. The received signal is applied to the digital signal processor 20 after passing through the A / D converter 10. The processing unit 20 processes each image signal suitable for various functions and outputs three signals, which are converted into analog signals by the D / A converter 30 and then provided to the encoder and the Y / C mixer 40. The encoder and the Y / C mixer 40 perform encoding and mixing operations according to the synchronization signal and the subcarrier frequency. Herein, the encoder and the Y / C mixer 40 are configured to selectively output the composite video signal or the Y and modulated color signal according to the use of the signal of the rear end to be connected to its output terminal. In FIG. 1, it can be seen that the clock required for modulation is used to modulate the color signal using two signals shifted by 0 ° and 90 ° phase after four divisions of the 4fsc clock of the oscillator 50. The encoder and the Y / C mixer 40 are blocks for processing analog signals. Specifically, the encoder and the Y / C mixer 40 receive analog signals of Y, RY and BY as inputs, insert synchronization into the Y signals, and input the RY / BY baseband signals. After the modulated color signal is generated using the fsc clock, the final video signal is output by adding the Y signal as the luminance signal.

In the encoder and Y / C mixer 40 of FIG. 1, it can be seen that the necessary signals are a burst gate pulse for inserting a burst signal, a compound synchronization signal, and an fsc (3.58 MHz) color subcarrier signal.

However, since the conventional technology as shown in FIG. 1 is analog signal processing, it is difficult to make ASIC, and a new encoder IC is required separately from the digital signal part, resulting in an increase in cost. In this case, the number of pins increases because a signal required for encoding must be output from a digital IC.

Accordingly, an object of the present invention is to provide an apparatus capable of digitally encoding an encoder and at the same time providing a necessary video signal according to the usage form of the video signal output.

It is another object of the present invention to provide an apparatus for realizing a conventional analog encoder and a mixer with a digital circuit and selectively obtaining a video signal output according to a use type.

In order to achieve the above object, the digital image signal processing apparatus of the present invention comprises: first means for inserting a composite synchronous signal into a luminance signal; Second means for providing a mixed and limited final composite video signal to a luminance signal output stage; Third means for receiving an input signal and various control signals to perform color modulation; And fourth means for selectively converting the color difference signals into a binary complement signal. When generating a digital composite video signal according to a desired output format, the apparatus uses digital logic to properly output the functions of color encoding, Y / C mixing, and composite synchronous synthesis, which have been processed in an existing analog encoder circuit according to a function selection. It is a circuit, which is responsible for the overall control for outputting the composite video signal through the Y, RY and BY outputs as well as the output in synchronization with the Y signal and the Y data output.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. 2 is a circuit diagram of the digital image signal processing apparatus according to the present invention, and FIGS. 3 and 4 are specific circuit diagrams of the mixer 200 and the color modulator 300 of FIG. 5 is an operation timing diagram of signals used and output in FIG. 2, and FIG. 6 is an operation table diagram related to the modulation operation of the color modulator 300 of FIG.

First, in the overall circuit diagram of FIG. 2, LAT1-LAT3 is an 8-bit flip-flop circuit for latching the Y, RY and BY signals, which are input digital baseband signals, and YCOMP is used to insert the Y signal when the video signal is inserted into the Y signal. A Y amplitude 3/4 compression block for scaling, ADD1 is a circuit that adds an offset value from the synchronous position by adding 64 values to this signal. MUX2 is a circuit for selectively outputting a sinkless Y signal or a sinking Y signal according to the selection of the input signal SYNCADD, and INV, NAND, and AND1 (8) are actually used to input a CSYNCB signal when the signal SYNCADD is a high signal. It is a circuit to insert. The Y / C mixer 201 and the limiter 202 are circuits for limiting the mixing and mixing of the Y signal with the modulated color signal. The color modulator 300 is a block in charge of modulating the color signal, and AND2 is a gate for output ON / OFF of the composite video signal. CONV1 and CONV2 are ON / OFF circuits for converting to straight codes, and LAT4-LAT6 are Y, R-Y, and B-Y final latches.

A detailed circuit diagram of the block 200, which is a second means for mixing and limiting the final composite video signal and providing it to the luminance signal output terminal, is shown in FIG. In FIG. 3, Add10 is a circuit for inserting two zeros into the MSB of the straight code for the Y signal and extending only the sine (sign) because the C signal is a binary complement code. NOR1 and NOR2 are Y / Limiter according to MSB 2 bit state after C mixing.

In FIG. 4, the AND1 of the color modulator 300 outputs an R2FSC signal when the MODON is a high signal, the MUX2 is responsible for multiplexing RY / BY according to the AND1 output, and Neg generates a negative value of the MUX2 signal. , AND2 / AND3 are MUX 4 selection signals generated according to the BFP position signal and RFSC, and INV and AND4 are the gates for generating the burst signal in the section where BFP is 1, and MUX 4 is the data and burst according to all input conditions. A circuit for multiplexing a signal. First, for Y signal, SYNCADD If the output of AND1 in FIG. 2 is a simple Y data output, but SYNCADD is 1, the output of AND1 in FIG. In YCOMP, the input Y signal is prescaled by 3/4, and then the image signal (Y) is shaped like 5D in the form of Add 1 to 64, and then the synchronized Y signal such as 5E timing is obtained through NAND and AND1. . This signal becomes a composite video signal through the Y / C mixer and limiter circuit of FIG. In FIG. 3, the Y signal is inserted into the MSB with 0 2 bits, and the modulated C signal is added with 2 bits of code extension and summed. If MSB is 1, the final output is unconditional (nex), bit (9: 8) is 1, the final output is FF. This is a limiting operation because Add10's operation is overflowed. That is, if bit (9: 8) of Add10 is 0, it is normal video signal, if it is 1, (+) overflow, 10 is not generated and 11 is (-) overflow.

Again, in FIG. 2, the output of the color modulator 300, which is a color modulation circuit, is transmitted to the Y / C mixer and simultaneously input to CONV1 for output only when color modulation is turned off or when color modulation is turned off. The B-Y signal is output via CONV2 at the separate output. Color modulation will be described with reference to FIG. First, when MODON is 0 (modulation off), AND1 is 0, MUX2 outputs R-Y, AND2 / AND3 are both 0, and MUX4 outputs R-Y signal to CMOD (7: 0). When MODON is 1, the output is determined according to BFP (Burst Flag Pulse), as shown in FIG. RFSC and R2FSC represent the subcarrier frequency fsc and 2fsc, which is twice the frequency. In the interval with BFP 1, burst signals repeating 0, -32, 0, 32 are inserted, and RY / BY-(RY) / The-(BY) signal is repeatedly multiplexed. The 8-bit data (7: 0) of inputs 2 and 3 of MUX 4 is a simple design of -32, +32, and 0, and can be composed of INV and AND4 only.

As described above, according to the apparatus of the present invention, it is possible to omit the external chroma encoder IC and the Y / C mixer circuit by the addition of the conventional analog circuit, and also to integrate the circuit by digital one chip. Then, the output of the desired format can be selected through the final Y terminal and the R-Y terminal. This has the effect of allowing a wide selection of the Y signal only, the composite Y signal, only the modulation signal C, R-Y / B-Y separated output, and the output of the Y / C mixed composite video signal.

Claims (7)

A digital video signal processing apparatus comprising: first means for inserting a composite synchronous signal into a luminance signal; Second means for providing, to a luminance signal output terminal, a final composite video signal in which the output signal of the first means is mixed and limited in order to provide a necessary video signal selectively according to the usage form of the output video signal; Third means for receiving an input signal and various control signals to perform color modulation; And fourth means for selectively converting the color difference signals into a binary complement signal. An apparatus according to claim 1, wherein said second means comprises an adder and a limiter. The apparatus of claim 1 wherein said third means comprises at least a multiplexer. The apparatus of claim 1, wherein the input signal is a color difference signal. 2. The apparatus of claim 1, wherein said fourth means further comprises a latch for latching a signal. In the digital video signal processing apparatus, in the digital logic, a signal in which the compound synchronous signal is inserted into the luminance signal is mixed and provided to the luminance signal output terminal, and the input signal and various control signals are received to selectively perform color modulation. An apparatus characterized by converting and outputting a binary complementary signal. A digital video signal processing method; Inserting a composite synchronous signal into the luminance signal; Mixing and limiting the final composite video signal to provide the brightness signal output terminal; Receiving an input signal and various control signals to perform color modulation; And selectively converting the color difference signals into a binary complement signal.