Most modern computers come with an ethernet adapter that has the capability to connect to another ethernet adapter without a crossover cable. This is called Auto-MDIX. Simply connect the network interface from one computer to the network interface on the other computer.
Once they're plugged in, there might be some sort of automatically-configured network setup. That may work in some cases, but not others. For fun and extra credit, let's create a new subnet for you to use just between the two computers.
First, we need to pick a "subnet" to use. It's easiest to use one different from your internal network. Let's choose 192.168.253.0/24. When you connect the two systems together, you'll need to give each system an IP address, as well as configure host names. Make sure you're configuring the wired, ethernet interface and not the wireless interface. All of this configuration can be done through the GUI.
Here's your network configuration for the Windows machine ("Use the following IP address"):
IP Address: 192.168.253.1
Subnet Mask: 255.255.255.0
Default Gateway: blank
While we're at it, don't configure DNS either, we'll do that later.
Here's your network configuration for the Ubuntu machine (Probably want to use some sort of "static" option, not sure on Ubuntu...)
IP Address: 192.168.253.2
Subnet Mask: 255.255.255.0
Default Gateway: blank
If everything's hooked up, you should be able to address each computer by their respective IP addresses. This lets you ensure that you are connecting to the wired, and not wireless interface. If you want to add hostname resolution, let's just make a change to the hosts file:
On Windows:
edit %SystemRoot%\system32\drivers\etc\hosts
, notepad will do.
Add the following line:
192.168.253.2 ubuntu-wired
You can replace ubuntu-wired with whatever name you want to use for that system.
And save.
On Linux:
edit /etc/hosts
, you'll need to do this as root with sudo or su.
Add the following line:
192.168.253.1 windows-wired
To test whether this works, ping each system using the name. The syntax is the same on both OSes. Open up a terminal window, and run the following:
ping HOSTNAME
, where HOSTNAME is the name you used above for the opposite machine.
Best Answer
You would need an adapter to convert the analog BNC video into a digital equivalent.
You could use a PCI card to maximize compatibility: http://www.newegg.com/Product/Product.aspx?Item=N82E16881127001
or try a simply USB adapted: http://www.dealextreme.com/p/bnc-to-usb-video-converter-cable-40cm-length-51935
google around for BNC to USB or PCI adapters and you'll have a ton of options. This is very possible, as well as cheaply and easily.