How to Capture Video on a Computer
People have been using computers for video capture and editing for years. After all, it's much easier to manipulate your footage when it's a digital file than when it's stuck on a tape where you have to fast forward and rewind to get to the good parts.
How Do You Choose a Capture Card?
Choosing the right video capture card for your computer starts with the computer. As with any accessory, the first thing you have to do is make sure that the card can physically fit in your motherboard. First off, this means you need a desktop computer with room in the case for the expansion card and enough hard drive space to store the resulting files. Note that uncompressed analog video can take up a lot of storage capacity. Most internal cards use one of two interfaces:
- PCI: Most common on older computers, the PCI interface is a 32-bit parallel interface offering 133 MB/sec of total bandwidth.
- PCI-Express: This newer interface is much faster, offering a minimum of 250 MB/sec per lane, but also less common on many computers.
What Kind of Inputs Do You Need?
The obvious answer to this question is that you need whatever inputs match your sources, but that's also a bit misleading. Many Pinnacle capture cards feature a breakout box that includes extra input, so you may not be limited to just the ones on the card. Breakout boxes are also popular because you don't have to reach around the back of the computer. Also, since most digital files can directly transfer to your computer without the need for a video capture card, you will primarily use it for analog inputs. There are three connectors you should consider:
- Composite: Composite video relies on a single analog cable to carry both color and luminance (brightness) information. It's easy to use but it can suffer in quality due to crosstalk between the two parts of the video signal.
- S-Video: This uses a single DIN connector with separate wires for color and luminance. It's also analog but has the advantage of increased quality because there's no interference between the two signals.
- FireWire: This digital port gives you a direct connection to MiniDV camcorders so you can capture digital video from tape.
Many PCI cards can use Pinnacle Studio software to capture video in the MPEG-1 format, which is about the same quality as VHS. Note that in order to record TV signals you need both an analog source and a TV tuner as the majority of cards do not come with digital video inputs beyond FireWire, which primarily appears on camcorders rather than TVs or cable boxes.