Re: Convert CCTV to Digital

["Bob La Londe" <usenet@xxxxxxxxxxxxxxxx>]

"Matt Ion" <soundy@xxxxxxxxxxxxxxx> wrote in message
news:GFivf.254457$ki.185322@xxxxxxxxxxx
> Bob La Londe wrote:
> > "Matt Ion" <soundy@xxxxxxxxxxxxxxx> wrote in message
> > news:rSKqf.52930$2k.49334@xxxxxxxxxxx
> >
> >>Bob La Londe wrote:
> >>
> >>>"Matt Ion" <soundy@xxxxxxxxxxxxxxx> wrote in message
> >>>news:Wdhqf.165576$Gd6.160875@xxxxxxxxxxx
> >>>
> >>>
> >>>>anthony.clendenen@xxxxxxxxx wrote:
> >>>>
> >>>>
> >>>>>I am open to any solution.  My main points are to get the image
storage
> >>>>>up to the office so that if the store gets broken into they don't
take
> >>>>>the video with them and to get it to a digital signal.  Currently
there
> >>>>>is only the one BNC cable that is going up to the office so I was
> >>>>>hoping to avoid having to run more cable and just use the one cable
> >>>>>coming up to the office.
> >>>>>
> >>>>>Would it be possible to have the cameras connect to some kind of
> >>>>>multiplexer that could send the video wirelessly up to the office and
> >>>>>then to a DVR card?
> >>>>
> >>>>The problem is, a multiplexer by definition takes the separate signals
> >>>>and provides a combined output, so even wirelessly, the MUX output
would
> >>>>be the same as with your single cable.
> >>>
> >>>
> >>>Nope.  A quad does that, but a true multiplexor sends single full frame
> >>>images sequentially. Some can do it based on activity.  A single
channel
> >
> > DVR
> >
> >>>that has settings for different standard multiplexors will record it
> >>>properly.  The DSR2000e by Kalatel will work with multiplexors upto 16
> >>>channels.  It has some other problems, but...  I don't like that
> >
> > particular
> >
> >>>recorder because of other issues.
> >>
> >>Ah yes, you are correct... but then there's also the issue of missing
> >>frames as they switch.  If the MUX outputs at 4FPS, 1FPS per camera is
> >>the most you're going to get on the DVR, which on modern units is pretty
> >>minimal.
> >>
> >>Either way, it's a rather inelegant solution.
> >>
> >>
> >>
> >
> >
> > Have you done it?  Actually a mux outputs typically at a much higher
rate
> > than that.
>
> On the VCR output, yes, but then you'll get one input on the DVR
> recording a fast sequence of changing images.  You could record it with
> a higher frame rate, but it would be a serious bitch to monitor, because
> you've have no way to selectively view only one camera.  It would have
> to selectively show every fourth or ninth or sixteenth frame during
> playback, and you would have to have it record constantly to avoid the
> frames going out of sync as they would with motion-detect recording
> (actually, the motion-detect function in software would probably see the
> switching as motion and trigger recording constantly anyway).
>
> DVRs are typically designed WITH multiple inputs, to record a SINGLE
> source per input.  IF you could find one that will selectively show only
> every fourth or ninth frame on playback, it would work, but there would
> be little point to such a thing, and thus little point in anyone making
> one.  If you know of such a device, I'd be interested to be proved
> wrong, but I'd expect them to be pretty rare, and subsequently fairly
> expensive for a single-input machine.
>
> The point is, as I said, even if possible, it's far from elegant or
> efficient.
>
>

Actually when I what I was originally thinking was an application actually
sduggested by Robot many years ago.  Take a Multiplexor and feed all your
cameras into it, then send it all up one cable and hook up another
multiplexor to seperate it back out.  However in this case I was thinking...
multiplexer to DVR.  Then use a PC if available right there to monitor it
instead of monitor plugged into the unit.  There are DVRs specifically
designed to work with multiplexors including the one I mentioned.

Still one must weigh the costs as you say.  What would it cost to run more
cable?  Is there any cat 5 or even telco you can steel pairs off of instead?
We know that modulating the individual cameras onto TV or cable channels to
send up the coax and then demodulating at the other end would be cludgy and
expensive.

Ultimately will the labor of one solution cost more or less than the
equipment of another.


--
Bob La Londe
www.YumaBassMan.com




> ---
> avast! Antivirus: Outbound message clean.
> Virus Database (VPS): 0601-2, 01/05/2006
> Tested on: 1/5/2006 4:16:20 PM
> avast! - copyright (c) 1988-2005 ALWIL Software.
> http://www.avast.com
>
>
>