JPH01216682A - Blanking period processing circuit - Google Patents

Abstract

PURPOSE:To output a video data in a blanking period accurately in the same form as the input by setting a FF circuit when a BLK value is obtained in a part to be applied with video data processing, holding it till the succeeding BLK value is obtained and outputting the video data as it is in the blanking period. CONSTITUTION:A 1-frame memory output is branched into three, a signal passing through the calculation for a picture processing circuit 14, a signal passing through a delay circuit 15 having the same delay as that of the picture processing circuit 14 for bypassing and a signal passing through a circuit 16 detecting a blanking value. When a blanking value is detected by the detection circuit 16, one-pulse is fed to a FF 17, where a consecutive BLK signal 18 is obtained. A selector 19 is turned to the position of the delay circuit 15 for the blanking period only and the input data is outputted as it is as the video processing output 20 during horizontal and vertical BLK periods. Thus, stable blanking period is reproduced in any phase different from the input phase and various kinds of information of the blanking period is held till the output without being lost.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a blanking period processing circuit.

[Conventional technology]

In conventional blanking period processing circuits, information contained within the blanking of a television video signal may disappear or be transformed by video processing.

[Problem to be solved by the invention]

In the conventional method described above, the information included in the blanking of the television video signal may disappear or be transformed by video processing. The current situation is that text information and text information are transformed midway through.

The purpose of the present invention is to be able to easily reproduce the blanking period no matter what phase the video data is in compared to the input video, to stop the video processing during blanking, and to reproduce the video data in the same way as by one person. The objective is to provide a circuit that can output accurately.

[Means to solve the problem]

In order to achieve the above object, the blanking period processing circuit of the present invention converts a television video signal into PCM data by A/D converting it, and then converts the input video signal into PCM data in a device that processes the video PCM data. means for forcing the leading and trailing edges of the BLK signal representing the blanking period obtained by the synchronized blanking period generator to a predetermined value (value B1) for at least l clock periods; If there is video data with the same value as the BLK value before switching to the BLK value, there is a means to shift the value by ILSB, and in the part that processes the video data, BL
When a K value is obtained, a flip-flop circuit is set and held until the next BLK value is obtained, a blanking period is determined, and the video data is output as is without processing during the blanking period. It has the following.

〔Example〕 Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

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

FIG. 2 is a conceptual diagram of the shift of video data and the phase of BLK value implantation.

In FIG. 1, 1 the present invention is an A/D conversion circuit 2.

Data shift circuit 3 and blanking implant circuit 4
, a synchronization separation circuit 5 , a clock generation circuit 6 , a blanking period generation circuit 7 , and a memory control circuit 11
, a one-frame memory 12 , an image processing circuit 14 , a delay circuit 15 , a BLK value detection circuit 16 , a flip-flop (F/F) 17 , and a selector 19 .

Next, the operation of the present invention will be explained using FIGS. 1 and 2.

The video input signal 1 is converted into a PCM signal by the A/D conversion circuit 2, and then converted into a value (here, 3C (1
(hex)) is included as video data, I
Shift the LSB value and replace it with a 3D value. In the blanking implantation circuit 4, the blanking period generation circuit 7
A blanking value is embedded in the video data according to the BLK signal 8 supplied from the video data. The above concept is illustrated in FIG. On the other hand, the blanking period generation circuit 7 determines a blanking period synchronized with the input based on the horizontal and vertical information 9 obtained from the human video synchronization separation circuit 5 and the clock signal 10 obtained from the clock generation circuit 6. The embodiment shown in FIG. 1 shows a case where the present invention is used in a video special effects device (DVE). Writing and reading of one frame memory 12 is controlled by the memory control circuit 11 from the signal 9.10. In the one-frame memory, human video data is written as is, and various calculations are performed on the reading side, but during the H and V blanking periods, continuous blanking information 13 from the blanking period generating circuit 7 causes continuous reading operations.

The L frame memory output is a signal that passes through the calculation for 1 image processing circuit 14 and a signal that passes through the operation for image processing circuit 1 for bypass.
The signal is divided into three branches: a signal passing through a delay circuit 15 having the same delay as 4, and a signal passing through a circuit 16 for detecting a blanking value. When the blanking value is detected by the detection circuit 16,
One pulse is supplied to the flip-flop 17, and the F/F 17 generates a continuous BLK signal 18.

Continuous BLK signal 18 is sent to selector 1 only during the blanking period.
9 to the delay circuit 15, and during the horizontal and vertical BLK periods, human data is output as is as the video processing output 2o.

〔Effect of the invention〕

As described above, the present invention has the advantage that a stable blanking period can be regenerated at any phase different from the input phase, and furthermore, various information of the blanking period can be maintained without loss until output.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 2 is a conceptual diagram of the shift of video data and the phase of BLK value implantation.

Claims (1)

[Claims] 1. Represents the blanking period obtained by a blanking period generator synchronized with the input video signal in a device that processes the video PCM data after A/D converting the television video signal to PCM data. A means for forcibly changing the leading edge and trailing edge of a BLK signal to one predetermined value (BLK value) for at least one clock period, and when there is video data with the same value as the BLK value before changing to the BLK value. There is a means to shift the value by 1LSB, and in the part that processes video data, when a BLK value is obtained, a flip-flop circuit is set and held until the next BLK value is obtained, and a blanking period is set. 1. A blanking period processing circuit comprising means for determining a blanking period and outputting video data as it is without performing any processing during the blanking period.