Nochains said:
I am about to order for a new PC to my PC vendor. My needs are regular
office work, internet, movies, music etc.
Now I need to add another feature to my PC, watching & recording(maybe)
my newly installed surveillance cameras.
Can any one help me, I need the cheapest and the best route, without
obstructing my regular office work.
Also can one use two monitors in one PC, one monitor could cotinously
display the camera while I work on the other.
Regards,
Kaal
Many video cards can support two monitors. Make sure the video card
comes with any necessary adapters (like a DVI-I to VGA dongle).
Some cards have a VGA connector (monitor #1) and a DVI-I connector
(monitor #2). A DVI-I to VGA adapter plug fits into the DVI-I
connector, if the second monitor has a VGA interface.
*******
For capture, there are a couple basic approaches. Capture a
video stream on a capture card, and compress the stream in
hardware. The result is a low bandwidth stream, which is easy to
carry for the system bus.
When the compressed stream gets to your processor, it has to be
decompressed. You would be decompressing four streams, to display
all four cameras at the same time. If you had a dual core
processor, one core could be pretty busy all the time,
decompressing the streams for display purposes.
A compressing video card, makes it easy on your system busses, but
makes it hard for the processor.
A second approach is to capture video in an uncompressed format.
This means a lot of data travels across the bus. But the processor
might not have a lot to do, since the data can immediately go to
the display. An example of this technology, is the BT848/BT878
series of capture chips (a quite old product). There are a ton of
cards using those chips on the market, ranging from some old WinTV
cards, to no-name products coming straight from Hong Kong via Ebay.
Now, to handle four cameras without any compromises, you would
want a card with four chips. Each chip captures all the data that
the camera has to offer. To send 640x480 at 30 frames per second
(30FPS) or 60 fields per second, would take 640x480 x 30 x 2 bytes,
if each pixel could be represented by 2 bytes of data. That is
18.4MB/sec per camera, or 73.6MB/sec for the whole card. If the
format used by the chip took 3 bytes per pixel, the numbers increase
to 27.6MB/sec per camera, or 110.4MB/sec. That would be about the
maximum that the PCI bus could handle, meaning if you got a motherboard,
you would aim to ensure the peripheral chips did not sit on the
same bus as the capture card. (I don't know what representation is
used for a pixel, on a BT878 card, and that is why I mentioned
both potential bus transfer rates.)
There is a *huge* web page, which lists all kinds of capture products.
If you are on dialup, this could take all night to load. When I
printed this page for future reference, it actually caused my
machine to start swapping
http://pvrhw.goldfish.org/bttv/
The first interesting "no-compromises" product I saw mentioned,
was this one. This is four BT878 chips, and a PCI 64 bit 66MHz
bus bridge. This is a no-compromises solution. This card can DMA
the captured frames directly to the frame buffer on the video card,
so there is no processor load (as long as you are not capturing to disk).
http://www.euresys.com/Products/picolo/PicoloTetra.asp
To use a card like that, you need a wider PCI bus. Most desktop
motherboards have a PCI 32 bit 33MHz bus. It takes a bit of
searching to find a board, that uses modern desktop processors,
and has a bus like that.
On the Intel side, I'd try something like this:
P5WDG2-WS (only suitable for LGA775 Intel processors but not Core 2 Duo)
http://usa.asus.com/products4.aspx?modelmenu=2&model=1031&l1=3&l2=11&l3=248
P5WDG2 WS Professional (LGA775 Intel processors including Core 2 Duo)
http://www.asus.com/products4.aspx?modelmenu=2&model=1289&l1=3&l2=11&l3=248
The "Professional" is the latest version, and supports Intel Core 2 Duo
processors. That is the one I would buy, and not the original version
(which may still be selling at retail).
This page compares the feature set:
http://usa.asus.com/products_compare_show.aspx?array_model=1031&array_model=1289
This is the Asus support page listing for E6600 Core 2 Duo processors. You
can see the "Professional" version of P5WDG2 listed near the bottom.
http://support.asus.com.tw/cpusuppo....40GHz,1066FSB,L2:4MB,rev.B2)&SLanguage=en-us
Asus P5WDG2 WS Professional 975X $329.99
http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=247090
On that motherboard, there are two busses. The bottom two slots are
PCI 32 bit 33MHz, and sit on their own bus. The next two slots are
PCI-X slots, and interface to a 6702 bus bridge. That separates
the PCI-X slots, and means you have two independent busses at
work. You can plug the Picolo Tetra product into the PCI-X.
AFAIK, the PCI-X slots are keyed for 3.3V. That means only a
3.3V PCI card, or a 3.3V/5V universal PCI card could go in there.
PCI-X cards are all 3.3V only. So you have to check the keying on
any cards you want to use, before buying them.
The bottom two PCI cards are keyed for 5V. A lot of single chip
BT878 based capture cards are 5V (they have a slot cut for the
5V key to fit). That means the BT878 based cards are not
universal cards. (A universal card has two slots cut, one slot
is cut for 3.3V and the second slot is cut for 5V.) So if you
bought individual capture cards (one capture card per camera),
you might need to buy different models to fit the lower two
PCI slots, versus the middle two PCI-X slots.
*******
The next proposed solution, might also work without compromises.
But it is hard to say.
In this case, I scour Ebay, looking for a PCI 32 bit 33Mhz bridged
quad BT878 type card. This product handles 16 cameras time multiplexed
(which you don't want) and handles 4 cameras in real time. Depending
on the PCI bus performance and other system limits, you might get
640x480 on four cameras at 15FPS or 320x240 on four cameras at
full frame rate. I don't know if it could run flat out, like the
Picolo above. (In the picture, I think the keying is for 5V PCI,
which is fine with most motherboard 32 bit 33MHz slots.)
http://cgi.ebay.com/CCTV-surveillan...6630807QQihZ015QQcategoryZ60839QQcmdZViewItem
For a motherboard, I look for a board which doesn't put the onboard
chips on the PCI bus. That way, only the video capture card
sits on the bus.
Asus P5B
http://www.asus.com/products4.aspx?modelmenu=2&model=1178&l1=3&l2=11&l3=307
The P5B uses a Realtek PCI Express ethernet chip and a Jmicron
JMB363 PCI Express storage chip. And that means there is nothing on
the motherboard that uses the old PCI bus. Then you plug your
"Ebay capture card", into one of the three PCI slots.
*******
If you wanted to use an AMD Athlon64 X2 dual core processor, for
the AM2 socket, then a board like this one, plus that "Ebay
capture card", might work:
Asus M2N ( AM2 socket, DDR2 memory, ordinary PCI bus 32bit 33Mhz )
http://www.asus.com/products4.aspx?modelmenu=2&model=1340&l1=3&l2=101&l3=340
If you do eventually get a box built up for you, and actually
get to use all four cameras, please post back with how well
the system works. There are other occasional posters who
are interested in real time surveillance, like your application,
and they'd like to know how well it works.
HTH,
Paul
