Special Features Available on Video Cards
In addition to performance factors and input/output connectors, the special features included on a video card should also be considered when choosing a card for your homebuilt PC. These features will greatly affect the usefulness of your finished homebuilt PC.
Some of the more popular features available on higher-end video cards include:
Some video cards include television tuners that can be used to receive input in the form of a radio-frequency television signal from a television antenna or cable TV system; or from any VCR, camcorder, security camera, or other device that outputs a broadcast-type RF television signal. The software accompanying the card usually allow the signal to be viewed on the computer as if it were a television, or exported in various formats to other programs for editing or archival.
Video cards are also available with HD (High Definition) tuners built in, and the tuners also are available as separate cards (or USB/Firewire devices). These allow you to view HDTV on the computer's monitor, or sometimes to be connected to an external television set or a Dish Television satellite box.
Hardware DVD Players
Many high-end video cards include hardware DVD players. Hardware DVD players decode and process most of the DVD data on the video card itself. By contrast, software DVD-viewing programs use the computer's resources to process the DVD data and present it to the user as audio and video. Hardware DVD players usually produce better playback quality while utilizing far fewer system resources. (Of course, to play DVD's on your computer, you will also need a DVD-ROM drive.)
Vidcap (short for "video capture") means making a still image from a video and saving it, usually as a JPEG file. It can also refer to a card that is able to capture a video from an external source (like a DVD player or camcorder) and save it as a file on the computer for later viewing or editing.
Some video cards include their own audio inputs and outputs, as well as audio processors that allow sound signals to be decoded from (or encoded into) mixed-media audio/video files or television signals. Often these cards utilize the HDMI interface, that is able to carry both audio and video.
Specialized Video Systems
Finally, a few video cards are specially designed to work as part of a dedicated audio/video editing system.
These systems used to cost tens of thousands of dollars and were used solely by professionals in the broadcasting or motion picture industries. Nowadays, however, very sophisticated systems capable of producing broadcast-quality video are available to amateur video enthusiasts for less than a thousand dollars (not including the cost of the computer itself).