Video capture usually refers to the various methods of digitizing analog
video to a computer from an outside source, such as a VCR or TV signal.
The term "video capture" is sometimes used interchangeably with the term
"video encoding". Analog video is digitally encoded during capture. However,
"capture" is usually used to describe analog to digital conversion, and
"encoding" is usually used to describe digital to digital conversion. A notable
exception to this is the transfer of DV video from a digital DV tape to a
computer via FireWire, which is nearly universally referred to as "DV capture".
Capturing full-motion video of what is displayed on a computer screen (to the
same computer) is sometimes also called "video capture", but the correct terms
for this are "video screen capture" or "screencast".
Capturing video from an outside source requires special hardware - like a
video capture card (such as
PCI or
PCI Express),
PCMCIA, or
USB or
Firewire based video capture device, and Video Capture Software.
Capturing video of what is displayed on the computer screen usually requires
special software. Operating systems do not have built-in mechanisms to record
videos of the screen (recording how the user moves his mouse around, clicks
icons, types text etc. as a movie). A multitude of utilities are available,
though. Many computer games have built-in video screen capture capabilities.
Video capture can also include the capture of TV from a
TV Tuner device that can be connected to the computer. Once captured, a VGA
to NTSC
video converter may be required to display the captured video on a regular
TV set (though many computers now have an NTSC video out port).
