• What is a TV tuner?
• How it works
• Interface: Internal or External
• Chipset
• Availability
• Software
• Time-shifting
• Electronic Program Guides
• Top tips for buying a TV tuner card

Software

One consideration that many overlook when shopping for digital TV tuner hardware is the software packages to drive the tuner. Because the hardware is next to useless without software, it's important to include the software that comes with the card as part of the buying decision. Poor software will make the tuner difficult to use, and a stable, full-featured and well-designed package will improve the TV viewing experience. Some of the features to look out for are time-shifting, scheduling (programming the tuner to record either a set show or for a set time period) and integration of an Electronic Program Guide (EPG). Some even include the ability to burn recorded TV directly to CD or DVD, which can be a massive time saver for serious users.

Time-shifting

Time-shifting is another compelling reason to go digital. Quite simply, time-shifting allows the viewer to pause a live TV broadcast and then resume it later on. Imagine you're watching a show and the phone rings. You press pause and answer the phone, but the computer keeps receiving the digital content while the show is paused. This information is written to the hard disk until you press pause again and continue playback. At this point, the recording will continue to buffer to the hard disk while you catch up. Using time-shifting, you can sit down to watch a half-hour show ten minutes after it started, and then press fast-forward to speed through all the advertisements while you're watching.

Time shifting also allows you to record shows and watch them later, and because digital TV is broadcast as an MPEG-2 stream, the computer only needs to decode the broadcast if it's playing it back. So, if you're not watching while you're recording, the PC can simply save the stream directly to the hard disk, which requires relatively little processing power. Bear in mind that this takes a large amount of hard disk space (approximately 1MB per second for an SD stream), so you'll want to regularly archive any recorded footage by burning it to CD or DVD. Also, keep in mind that if you are recording programs to the hard drive, you will require a significantly higher storage capacity to record HD programs as it records at between 2-3MB per second.

Electronic Program Guides

One issue that has stifled the uptake of digital tuners in Australia is the slow offering of an Electronic Program Guide (EPG). An EPG allows the user to schedule recordings based on the show listings. Instead of setting up a VCR to record a certain channel at a certain time, as in the past, you can set the software to record a certain show every day of the week. The software can be configured to start recording when the show comes on, and then turn off when the show finishes.

The program information is broadcast over the air as binary information that can be received by the software, or as a video stream that can be read by the user. There is also commercial EPG subscription-based services. Ice TV lists EPG information for Australia, which can automatically be downloaded to your PC and used for easier and detailed scheduling. They also offer a service called PIMP which allows you to schedule programs from any computer connected to the Internet or even using your 3G mobile phone.