RE: CCTV camera on TV

["Paul Gordon" <paul@xxxxxxxxxxxxxxxxxxxxx>]

I have seen something like this before, and IIRC it was something to do
with the "video overlay" mode... If I have understood the concept
of
what was going on correctly, (and it's *extremely* likely that I
haven't!), I think the problem was something along the lines of the PC
graphics card is not responsible for rendering the video part of the
display, but instead just leaves a blank "hole" in the screen
where
another bit of hardware or software then "fills in" the gap with
the
video...

I saw this result in an annoying feature of my Matrox G400 dual-head
graphics card that only (as I now know) supports video overlay on one of
the two displays. This meant that when I tried to play DVD's, media
player would come up; I'd get the sound, but no video... It took me ages
to figure out what was going on, since I thought I had the wrong codec's
installed or something, and since the two displays were in different
locations (and couldn't both be seen at once), it took me a while to
realise that the video displayed OK on the other monitor.... swapped the
VGA plugs around, and viola, I had the DVD video on the display where I
wanted it...

This sounds like it could be your problem, and since the graphics card
isn't rendering the video part of the display, I guess there's no way
you'll ever capture it by doing a screen grab, which I guess just grabs
the data stream from the graphics card...

Sound plausible? - If not, I'm sure someone far more knowledgeable on
this subject will be along shortly to correct me...

Paul G.



-----Original Message-----
From: Stephen Jones [mailto:ukha@xxxxxxx]
Sent: 30 December 2004 18:51
To: ukha_d@xxxxxxx
Subject: RE: [ukha_d] CCTV camera on TV


Mark

Recently I tried to modulate the "TV Out" of the graphics cards
but for
some
reason couldn't get the GV images to be displayed on the TV.

I could get the PC video to be displayed on the TV but the GV images
would
not. IIRC everything was being displayed on the TV apart from the GV
images.
Even if I took a screenshot using "PrintScreen" and then tried
viewing
the
jpeg using an app like Paint it still wouldn't display the camera image.

Have anyone ever heard of that happening before? Maybe it was just that
particular video card.

Steve

-----Original Message-----
From: Mark McCall [mailto:lists@xxxxxxx]
Sent: 30 December 2004 17:56
To: ukha_d@xxxxxxx
Subject: RE: [ukha_d] CCTV camera on TV

> like to be able to display the output on the TVs. To do this I think I
> need the Real Time Display card - correct?.

I modulate mine round all the TVs in the house (without the relatime
card) -
look here...
http://www.automatedhome.co.uk/contentid-7.html

I just use the composite "TV Out" from my graphics card and feed
it into
a
modulator.  I think the difference the realtime card gives you is max
framerate on each camera, rather than the restricted frame rate of your
card.

> some way to chose which one or select which one I want to view??

You can display multiple cams at once like this...
http://www.biometria.com.pe/geovision19.jpg
http://mipagina.cantv.net/redondo/gv_principal.jpg
or you can have them on a timer showing in sequence etc.

M.