How to Build a DVR

TV Capture Cards

A typical computer doesn't have a video input that can accept a signal from a antenna or a set-top cable or satellite box. You'll need a TV capture card, which has its own tuner to receive television signals, to take the incoming signal and read it. Better capture cards have onboard processors that handle the encoding of the signal into the digital format the show will be saved as. A capture card that does its own encoding takes a lot of stress off the computer's main processor. In fact, if you use this type of card, you won't need a powerful main processor.

One important thing to look for in a video capture card is the ability to accept an MPEG-2 transport stream in both DBV and ATSC, sometimes referred to as digital hardware cards. That technical jargon simply refers to the format that TV shows are transmitted in over digital broadcasting networks. With the United States and many other countries switching to all-digital broadcasting, you'll want to avoid older capture cards that only accept analog signals. Many cards can handle both analog and digital signals.

A typical capture card will allow a user to record up to two programs at the same time while watching a third. If you want to record even more programs simultaneously, you'll need to install an additional capture card. But remember to make sure your power supply can handle the extra load.

Installing a video capture card isn't difficult. Most cards are PCI or PCI-Express cards -- they fit into slots on the motherboard of your computer. After removing the cover of your computer, the card is installed by pressing it firmly into the appropriate slot. The card is then secured with a single screw. There are also video capture devices available that are even easier to install. They plug into to any available USB 2.0 port.

In the next section, we'll find out what software you can use to watch and record TV programs.