TV Tuner Cards

What is a TV tuner?

Digital TV has slowly gathered momentum in Australia thanks to its clear advantages over traditional analogue broadcasting. Digital set top boxes have come down in price over the last year but are still relatively costly. The good news is, if you've already got a PC you're a couple of short steps away from enjoying DVD-quality TV at home.

Australian TV networks have been broadcasting digital content since January 2001. Initially, the broadcast area was limited, but it has grown steadily, and now encompasses most of Australia's populated regions. Digital television brings a range of benefits to consumers, including support for widescreen broadcasts (in a 16:9 aspect ratio,) higher quality sound including the Dolby Digital 5.1 surround format, and high definition support, where broadcast images are at a higher resolution than standard TV or DVD.

Since 2001, the promise of digital television has been hampered by government regulations. One of the most exciting things about digital television was the potential of multi-channel broadcasting. This is where a television network could broadcast more than one channel in their transport stream. SBS had a service called SBS Essential that ran from October 14, 2002 to January 25, 2007. It was a support channel for SBS which gave constant news, weather and sports headlines as well as SBS programming schedules. Currently SBS has a dedicated news channel and ABC has an ABC 2, a channel with new and time-shifted content. Due to restrictions from government media regulations, the commercial channels have not been able to use multi-channeling to its potential. The second channels of the seven, nine and ten consist of nothing but scheduling information. However, many of the restrictions were lifted with the new media ownership laws passed through parliament on October 18, 2006. Whether they adopt the concept of multi-channeling remains to be seen.

Another, possibly more compelling, reason to move to digital is the fact that the signal isn't subject to interference. Because the stream is broadcast as digital MPEG-2 video (the same format used for DVD, albeit at a slightly different quality), the image is clear and crisp. What's more, the digital signal is broadcast in the same spectrum as analogue UHF, so the signal can generally be received without needing to upgrade the antennas. Making the switch to digital is simply a matter of installing a compatible tuner (as either a digital set top box or expansion card for a PC).

Where dedicated digital TV set top boxes are designed to sit in a lounge room and enable a regular TV to receive digital content, digital TV tuner cards are designed to receive digital television broadcasts for playback on a PC. They're relatively good value compared to dedicated set top boxes as the computer can perform some of the required signal processing, therefore simplifying the tuner.

Home Theatre PCs (HTPCs) have been popular in geek circles for years, but the relatively recent availability of MPEG-2 TV Tuners and Microsoft's Windows Vista and XP Media Centre Edition 2005 operating systems have sparked widespread interest. PC-based digital TV tuners come in three flavours: High Definition (HD), Standard Definition (SD) and a hybrid of the two. More on that later...

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How it works

Digital TV Tuner cards for computers are relatively simple pieces of hardware: in essence, they include a regular coaxial aerial connector, a RF tuner, and a decoder. The signal hits the antenna, is passed down to the tuner and then to the decoder. The information is then processed by either a dedicated MPEG-2 decoder or the computer's processor. A basic digital TV tuner kit will include a TV tuner card and some software to record and watch TV.

Most mid-range TV tuner bundles also include a remote control and infrared receiver, which is used to drive the tuner software. These will often include a digital radio tuner, too, which also allows the user to receive digital radio broadcasts. Basic models often forego the remote control, but if you're planning on using the computer as a TV, it's a crucial component.

Interface: Internal or External

The first choice to make after deciding to go with a digital TV tuner card is figuring out whether you want to opt for an internal or external solution. Digital TV tuners are available as both internal cards that fit into a PCI slot or as external USB devices.

An internal card requires a spare PCI slot, as well as a desire to open your computer up to install it. This isn't technically challenging, just a little daunting if you've never done it. PCI Express models are also available that take advantage of the PCI Express bus found on newer motherboards. These are functionally similar to the internal PCI models but are designed to fit the PCI Express slot instead. Internal cards tend to be cheaper than their external brethren, but they're a little less flexible.

Internal cards start around $99 and go up to $250. Generally, a basic model will include a card, some tuner software, and little else. The card will include a coaxial aerial connector, but you'll have to go shopping for coaxial cable yourself, and if you're serious about watching TV from a distance you'll also have to add a third-party USB or Serial infrared remote control. These cards are generally adequate for recording shows though, and if your primary goal is to be able to watch TV while sitting at a PC this solution is ideal. Higher-end models will generally include more cabling, a wider range of connectors, a remote control, richer software bundle, as well as extra filters to clean the image. As a result, they'll offer a slightly superior picture to less expensive models, but the difference isn't enormous.

Some high-end tuners will even include analogue inputs, allowing the user to record footage from a VCR. This sort of device can do double duty: it can be used to receive and record broadcast TV and also for converting old VHS, Super 8 or Beta tapes into a digital format.

An external device is the only viable solution for notebook users while also favouring those that don't want to mess around opening their computers. Better yet, they're portable. You're generally looking at a slight price premium to move from an internal to external solution. When buying an external tuner, the best bet is to go for a USB 2.0 or Firewire model. This is because the limited speed of USB 1.1 (11Mbps) isn't adequate for the data passing between the tuner and the PC. To avoid any playback glitches, Firewire (400Mbps) and USB 2.0 (480Mbps) of bandwidth respectively, which is plenty to cover the demands of a digital TV tuner. External tuners start at around $120 and go up to $300. Like their internal counterparts, the more expensive models feature extra software, cabling and often ship with a remote control.

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Chipset

One of the key features to keep an eye out for when shopping around is the chipset used by the tuner. The chipset refers to the manufacturer of the decoder chip and can often be a good indicator of the quality of the image that you will get and the available software support. It's always best to go for a popular chipset if possible, as this will increase the number of compatible software packages that will work with the card. In particular, keep an eye out for cards with chipsets manufactured by Philips. The chipset is generally listed on the packaging, so do a little shopping around before committing to a purchase. If you're shopping at a larger store, ask the shop staff for a demo of the product in operation. This way, you can judge for yourself if the display quality is adequate.

Technically, there are two types of digital TV broadcasts: Standard Definition (SD) and High Definition (HD). SD is broadcast at a resolution of 720x576 which is 576 lines of resolution, while HD supports up to a massive display resolution of 1920x1080 which is 1080 lines. Because HD is broadcasting much more information than SD, the decoding requirements are higher, but the broadcast image is astonishingly clear and crisp. Many channels offer separate analogue, SD and HD broadcasts simultaneously, but while HD is growing in popularity, it will still be a while before it takes over completely.

Availability

Though the rollout has been slower than many would like, digital TV is available across most of Australia. Standard definition is available in capitals and most regional centres (for a chart detailing what's available where, see DBA). All major channels are currently available in SD, so there's very little reason to opt for a regular analogue tuner these days.

If you live in a metropolitan centre, you may want to consider picking up a HD digital tuner. Keep in mind that not all your favourite shows are available in HD and there are periods of the day when no HD content is offered. It will be a couple of years before all the broadcasters make all their content available in HD, so check out the program availability before making the switch.

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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.

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Top tips for buying a TV tuner card

• Start by ensuring you can receive digital SD or HD broadcasts in your area by visiting DBA).
• Decide whether you prefer an external or internal tuner.
• Narrow down your possible choices by checking software bundles and chipsets.
• Choose a tuner with a remote control if you want to watch recordings from a distance.
• Ensure your software includes desirable features like CD/DVD burning, time shifting, and scheduling.
• Shop around. Prices can vary widely between stores, so it pays to contact a few vendors before committing.