Re: HELP! Detecting Video Black and VCR Single Frame Recording

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Article #383

#383

From: Gary Coffman
Date: Tue, 03 Nov 1992 01:01

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In article <1992Oct30.154558.504@cho006.cho.ge.com> sant_m@cho006.cho.ge.com writes:
>>>... I need some way to detect the difference between
>>>video black (ie the short 'blank' spot between commercials) and anything
>>>else (ie any other signal or picture) on a video tape.

True TV black has nothing above the 7.5 IRE blanking level. So all you
have to do is clamp the video to the back porch of H sync and use a 
comparator to detect any voltage above 7.5 IRE. If you find any, you're
not looking at black. Simple.

Gary

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Message-ID: <1992Nov3.010130.21683@ke4zv.uucp>

Path: arc1-ca.pugleaf.net!sparky!uunet!cis.ohio-state.edu!zaphod.mps.ohio-state.edu!swrinde!emory!kd4nc!ke4zv!gary

References: <1992Oct22.101318.492@cho006.cho.ge.com> <BwnotA.Jn4@zoo.toronto.edu> <1992Oct30.154558.504@cho006.cho.ge.com>

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Newsgroups: sci.electronics,rec.video
Path: arc1-ca.pugleaf.net!sparky!uunet!cis.ohio-state.edu!zaphod.mps.ohio-state.edu!swrinde!emory!kd4nc!ke4zv!gary
From: gary@ke4zv.uucp (Gary Coffman)
Subject: Re: HELP! Detecting Video Black and VCR Single Frame Recording
Message-ID: <1992Nov3.010130.21683@ke4zv.uucp>
Reply-To: gary@ke4zv.UUCP (Gary Coffman)
Organization: Gannett Technologies Group
References: <1992Oct22.101318.492@cho006.cho.ge.com> <BwnotA.Jn4@zoo.toronto.edu> <1992Oct30.154558.504@cho006.cho.ge.com>
Date: Tue, 3 Nov 1992 01:01:30 GMT
Lines: 12

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