JPH04319878A - Video synthesizing device - Google Patents

Abstract

PURPOSE:To execute the various video synthesis without being restricted by the priority at the time of video synthesis. CONSTITUTION:A video signal switching circuit 1 is provided with at least (m+n) pieces of input terminals for receiving video signals V1-Vm and output video signals V11-V1n of video mixing amplifying circuits 11-1n, and also, provided with 2n pieces of output terminals and one piece of video synthesizing output terminal for selecting the video signal and outputting it to each video mixing amplifying circuit. A key signal switching circuit 2 is provided with at least (x+y) pieces of input terminals for receiving a key signal from key signal generating circuits 21-2x, 31-3y, and also, (n) pieces of output terminals for selecting the key signal and outputting it to each video mixing amplifying circuit. The video mixing amplifying circuits 11-1n synthesize two video signals selected by the video signal switching circuit 1, respectively in accordance with the key signal selected by the key signal switching circuit 2.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for synthesizing television signals.

0002

2. Description of the Related Art A conventional video synthesis apparatus, as shown in FIG. A plurality of key signal generation circuits 45 to 47 are provided corresponding to the mixing amplification circuits. The key signal generation circuit 45 is a circuit that independently generates a key signal, while the key signal generation circuits 46 and 47 are circuits that process external video signals and generate key signals. Video mixing amplification circuits 42 to 44 combine two video signals in accordance with the respective key signals from key signal generation circuits 45 to 47. As shown in FIG. 3, the video mixing amplification circuit 42 combines video signals S1 and S2 according to the key signal KY1 and outputs a composite video signal S10. The video mixing amplification circuit 43 combines the video signal S3 and the composite video signal S10 according to the key signal KY2, and outputs the composite video signal S20. Similarly, although not shown, the video mixing amplifier circuit 44 combines the video signal synthesized by the video mixing amplifier circuit 43 and the video signal S4 from the video signal switching circuit 41.

0003

[Problems to be Solved by the Invention] In the above-mentioned conventional video synthesis device, the key signal generation circuit is fixedly set corresponding to each video mixing amplification circuit. The problem is that the priority during synthesis is set.

[0004] An object of the present invention is to provide a video compositing device that can perform various video compositing without being restricted by the priority of video compositing.

[0005]

[Means for Solving the Problems] The video synthesis device of the present invention provides a plurality of (n) video signals for synthesizing two video signals according to a key signal.
) video mixing amplification circuits, a plurality (k) of key signal generation circuits that generate the key signals, n composite signals output from the video mixing amplification circuits, and a plurality (m) of composite signals input from the outside. a video signal switching circuit having at least n+m input terminals for receiving video signals, and having at least 2n+1 output terminals for selecting and outputting the video signal according to a control signal; and a key output by the key signal generation circuit. a key signal switching circuit having at least k input terminals for receiving signals and having at least n output terminals for selecting and outputting a key signal according to a control signal; and a switching control circuit for generating the control signal. Configured with the necessary features.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the video synthesis device of the present invention, which includes a video signal switching circuit 1 that selects and outputs a plurality of input video signals, and a video signal switching circuit 1 that selects and outputs a plurality of input video signals. a key signal switching circuit 2 that outputs a key signal, a switching control circuit 3 that controls switching between the video signal switching circuit 1 and the key signal switching circuit 2, and a plurality of video mixing amplifiers that synthesize two video signals according to the key signal. Circuits 11 to 1n,
A plurality of key signal generation circuits 21 to 21 generate key signals by themselves.
2x, and a plurality of key signal generation circuits 31 to 3y that process external video signals to generate key signals.

The video signal switching circuit 1 receives a plurality of external video signals V1 to Vm and video mixing amplification circuits 11 to 1.
In order to receive composite video signals V11 to V1n from
It has at least m+n video signal input terminals,
In addition, the video mixing amplification circuit 1 selects the video signal to be input.
2n output terminals for sending to 1 to 1n, and 1
It has two video synthesis output terminals.

The key signal switching circuit 2 has at least x+y key signal input terminals for receiving key signals from the key signal generating circuits 21 to 2x and 31 to 3y, and also has at least x+y key signal input terminals. It has n key signal output terminals for selecting and sending out key signals K1 to Kn to a plurality of video mixing amplification circuits 11 to 1n.

The video mixing amplification circuits 11 to 1n convert the two video signals selected by the video signal switching circuit 1 into key signals K1 to Kn selected by the key signal switching circuit 2.
Combine them accordingly.

In this way, the video signals synthesized by the video mixing and amplifying circuits 11 to 1n are supplied to the input terminal of the video signal switching circuit 1 for selection as appropriate, and the key signal switching circuit 2 selects a plurality of key signals as appropriate. By doing so, it is possible to arbitrarily control the combining priority regardless of the connection order of the video mixing amplification circuits.

0012

As explained above, the present invention provides a video signal switching circuit and a key signal switching circuit, and transfers composite video signals output from a plurality of video mixing amplification circuits and external video signals to the video signal switching circuit. In addition to supplying the key signals to the input terminals and making the appropriate selections, the key signals output from the plurality of key signal generation circuits are also supplied to the key signal switching circuits, which make the appropriate selections and supplying them to each video mixing amplification circuit. Depending on the connection order of the video mixing amplification circuits, it is possible to perform a variety of video combinations without being constrained by the priority during video combination.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a block diagram showing an example of a conventional video compositing device.

FIG. 3 is a diagram illustrating an example of the operation of the conventional video synthesis apparatus shown in FIG. 2;

[Explanation of symbols]

1 Video signal switching circuit 2 Key signal switching circuit 3 Switching control circuit 11-1n Video mixing amplification circuit 21-2x, 31-3y Key signal generation circuit V1
~Vm Video signal V11~V1n Combined video signal K1~Kn Key signal

Claims (1)

[Claims] 1. A plurality of (n) video mixing amplification circuits that synthesize two video signals according to a key signal, a plurality (k) of key signal generation circuits that generate the key signal, and a plurality of (k) video mixing amplifier circuits that synthesize two video signals according to a key signal; At least 2n+1 input terminals that have at least n+m input terminals that receive n composite signals output from the amplifier circuit and a plurality (m) of video signals input from the outside, and that select and output video signals according to control signals. a video signal switching circuit having an output terminal; and at least n output terminals having at least k input terminals for receiving key signals output from the key signal generation circuit and selecting and outputting a key signal according to a control signal. A video synthesizing device comprising: a key signal switching circuit having a terminal; and a switching control circuit generating the control signal.