JPH06189347A - Video signal converter - Google Patents

Abstract

PURPOSE:To convert all video signals recorded by a D-2 equipment into signals with a format for a D-1 equipment and to convert all video signals recorded by the D-1 equipment into signals with a format for the D-2 equipment. CONSTITUTION:A luminance signal Y of a component video signal inputted from a D-1 equipment 1 is fed to a Y signal level converter 6, in which nonlinear processing is applied to a video signal whose level is a prescribed level or below. The luminance signal Y subject to nonlinear processing is fed to an encoder 7, in which the signal forms a composite signal with a chroma signal C. The composite signal is fed to a D-2 equipment 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal conversion device capable of converting the format of a digital video signal.

[0002]

2. Description of the Related Art In a VTR for recording a digital signal, a digital VTR intended for a component signal
A digital VTR (hereinafter, referred to as a D-1 machine) (hereinafter, referred to as a D-1 machine) and a composite signal are known. By the way, in the D-2 machine, a signal at a level which is not used in the video signal of the D-1 machine format is used for the special processing of the video signal. This signal is recorded as a signal (hereinafter referred to as a key signal) having a level lower than the black level of the video signal used in the D-2 machine.

The signal standard defined by the D-2 machine is different from the signal standard defined by the D-1 machine. Further, in the video signal recorded by the D-1 machine, a start active video signal (hereinafter referred to as SAV) indicating its start point and an end active video signal (hereinafter referred to as EAV) indicating its end point are included. Is added. The following is a table of 8-bit and 10-bit values of video signals in the D-1 standard and the D-2 format.

[0004]

[0005]

Here, for editing, for example, the video signal recorded by the D-2 machine is converted into a video signal of the format of the D-1 machine, and the video signal is further converted into a D-video format. -Refer to the case of recording with two units.
The minimum level of the relative level between the D-1 aircraft and the D-2 aircraft is different, and when the minimum level of the D-1 aircraft is made to correspond to the minimum level of the D-2 aircraft and expressed as a relative level, the minimum level of the D-1 aircraft is The level is -6,85%. By the way, the level of the key signal recorded in the video signal of the D-2 machine is -10 to -3.
0% (8IRE% or less based on black level)
Is. Therefore, the key signal present in the video signal of the D-2 machine cannot be obtained in the video signal of the format of the D-1 machine.

Therefore, an object of the present invention is to edit a video signal using the D-1 and D-2 machines.
It is an object of the present invention to provide a video signal conversion device capable of obtaining a signal corresponding to the key signal of the D-2 machine even in the D-1 machine.

[0007]

SUMMARY OF THE INVENTION The present invention is a video which is provided with a first video signal recorded in a first format and which converts the first video signal into a second video signal in a second format. A signal conversion device, which is a video signal conversion device having conversion means for performing non-linear processing on a signal of a predetermined value or less in a first video signal to convert it into a second video signal.

[0008]

The key signal in the video signal recorded in the format of D-2 machine is subjected to the non-linear processing to be converted into the video signal of the format of D-1 machine. Also, D-1
A signal of a predetermined value or less in the video signal of the D-2 format is subjected to non-linear processing and converted into a video signal of the D-2 format.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a video signal converter according to the present invention will be described below with reference to the drawings. The video signal conversion system of FIG. 1 includes a D-1 machine 1, a video signal conversion device 2 and a D-2 machine 3. The video signal recorded in the D-1 machine 1 (for example, the video signal recorded in the format of the D-2 machine) is supplied to the interface 4 of the video signal conversion device 2. Here, the luminance signal Y and the chroma signal C are formed from the component signals. In addition, D-
When the video signal recorded in the one unit 1 is the original video signal of the D-1 unit, the interface 4 detects the SAV and EAV in the video signal in addition to the formation of the luminance signal Y and the chroma signal C. . The SAV and EAV have information indicating whether they are horizontal active video or vertical active video, and whether the interlaced field is an even field or an odd field. It also has information to indicate.

The luminance signal Y is supplied to the Y signal rate converter 5 and converted into the Y signal of the standard of the D-2 machine. That is, the sampling frequency of the luminance signal Y is 13.5 MHz
Is converted to 14,318 MHz. Thereafter, the Y signal level converter 6 having a non-linear characteristic converts the video signal level in the format of the D-1 machine into the video signal level in the format of the D-2 machine, and the encoder 7
Is supplied to. On the other hand, the chroma signal C is supplied to the C signal rate converter 8 and converted into the C signal of the standard of the D-2 machine. That is, the sampling rate of the color signal C is half that of the luminance signal Y, so that the sampling frequency of the color signal C is converted from 6,75 MHz to 7,16 MHz. After that, the C signal level converter 9 having a linear characteristic converts the video signal level of the format of the D-1 machine 1 into the video signal level of the format of the D-2 machine 3 and supplies it to the encoder 7.

The encoder 7 generates a composite signal based on the component signal supplied from the D-1 unit 1 and outputs a video signal corresponding to the standard of the D-2 unit 3 to the D- unit.
Supply to 2 aircraft 3.

FIG. 2 shows a detailed circuit block diagram of the Y signal level converter 6 formed in the video signal converter 2 according to the present invention. In FIG. 2, the video signal V from the Y signal rate converter 5 is supplied to the terminal 11. Further, the reference signal D is input to the terminal 12.
The reference signal D is replaced with the video signal V when the video signal V is equal to or lower than a predetermined value, and corresponds to the level of the key signal of the D-2 machine. The video signal V is supplied to one input terminal of the comparator 13 and one terminal 14 a of the selector 14. The reference signal D is supplied to one input terminal of the comparator 13 and the other terminal 14 b of the selector 14. The output terminal 14c of the selector 14 is connected to the encoder 7 via the terminal 15.

The comparator 13 compares the input video signal V with the reference signal D. here,
When the video signal V is larger than the reference signal D, the control signal CS is output from the output terminal of the comparator 13 to the selector 1
4 is supplied. By this control signal CS, the selector 1
The four output terminals 14c are connected to the terminal 14a. Therefore, the video signal V is supplied to the encoder 7 via the terminal 15. When the video signal V is smaller than the reference signal D, the control signal CS is not supplied to the selector 14. Therefore, its output terminal 14c is connected to the terminal 14b. As a result, the reference signal D is supplied to the encoder 7 via the terminal 15. In this way, it is detected whether or not the video signal V is less than or equal to the predetermined value, and if the signal is greater than the predetermined value, the video signal V is detected, and if the signal is less than or equal to the predetermined value, the reference signal D is detected. Is supplied to the encoder 7. As a result, it becomes possible to convert all the video signals supplied from the D-1 unit 1 into video signals conforming to the format of the D-2 unit 3.

FIG. 3 shows a PROM of the Y signal level converter 6 formed in the video signal converter 2 according to the present invention.
A circuit block diagram in the case of the above configuration is shown. In FIG. 3, the video signal V from the Y signal rate converter 5 is supplied to the PROM 22 via the terminal 21. PROM2
2 is provided with a non-linear table, and the signal corresponding to the input signal (minimum level) of a predetermined address is D-
It is set as a key signal of the format of 2 units 3. Therefore, when the minimum level signal is supplied to the PROM 22, its output is supplied to the encoder 7 via the terminal 23 as a key signal in the format of the D-2 machine.

The structure of the Y signal level converter 6 is not limited to that described above, and the same effect can be obtained by using a combination circuit such as TTL.

[0016]

According to the present invention, when a video signal recorded in the format of the D-2 machine is converted into the format of the D-1 machine and then converted again into the format of the D-2 machine, it is originally present. The key signal can be converted again, and the video signal can be easily edited. Also, record the underlying video signal with a D-1 machine and
In the case of editing with the -2 device, the key signal can be created from the original video signal, the workability of editing and the like can be improved, and a highly accurate signal can be obtained. Therefore, the editing efficiency can be improved and the range of use of the D-1 and D-2 machines can be expanded.

[Brief description of drawings]

FIG. 1 is a circuit block diagram of a video signal conversion system to which a video signal conversion device according to the present invention is applied.

FIG. 2 is a circuit block diagram of a Y signal level converter.

FIG. 3 is a circuit block diagram when the Y signal level converter is configured by a PROM.

[Explanation of symbols]

 2 video signal converter 5 Y signal rate converter 6 Y signal level converter 13 comparator 22 PROM

Claims (3)

[Claims] 1. A video signal conversion device which is supplied with a first video signal recorded in a first format and converts the first video signal into a second video signal in a second format, A video signal conversion device having a conversion means for performing non-linear processing on a signal of a predetermined value or less in the first video signal to convert the signal into the second video signal. 2. The video signal conversion apparatus according to claim 1, wherein the conversion means is a ROM. 3. The video signal conversion device according to claim 1, wherein the conversion means comprises a comparator.