HDMI

Analog video cables, such as component, composite or S-Video, are currently the main methods used to transfer picture signals in an average home system. Component is the highest quality analog cable as it breaks down the picture signal into three different cables - one each for red, blue and green. When you've got analog cabling connecting digital sources (such as an LCD or plasma screen with a DVD), the digital video or sound signals have to be converted into analog to travel through the cable, before being re-converted back into digital at the receiving end.

This could lead to some signal degradation and a resulting loss in output quality.
HDMI can deliver high quality sound or vision without the risk of quality loss due to the conversion or compression of a video or audio signal. HDMI pictures should be smoother and sharper, with a distinct reduction in video noise.

Sound should be crisp and taut, without any distortion. And of course, using the single cable HDMI can get rid of a lot of snaking around your home theatre kit.
Because of its digital nature, HDMI also works well with fixed-pixel displays such as LCD, plasma or DLP screens and projectors.

A HDMI cable allows you to exactly match pixel-by pixel the native resolution of the screen with whatever source device you've got connected. HDMI systems will also automatically convert a picture into its most appropriate format, such as 16:9 or 4:3.
HDMI has some built-in smarts that allow you to control any device connected via HDMI through the one remote.

Since the HDMI connection allows two-way communication between devices, it gives you basic universal remote-like functions which, for example, can tell a HDMI-linked system at a press of a button which components to turn on or off when you want to watch a DVD.
You may have heard of digital video interface (DVI), which is another all-digital connector for video. DVI has been around for longer, and can be found in many more televisions and other devices than HDMI.

DVI was initially developed as a connector between PCs and monitors, but eventually found its way into the home entertainment world.
The HDMI standard is actually based on DVI, so picture quality on both should be similar. Where HDMI has it over DVI is its audio capabilities - DVI can only carry video signals.

HDMI cables can also be made longer than DVI - HDMI can go up to 15m in length. And from an aesthetic viewpoint, HDMI connectors are less bulky than DVI ones. HDMI connects like a USB device for PCs, while DVI still has screw pins on its connector.

Never fear - HDMI is fully backwards compatible with DVI, so you won't be making your DVI products obsolete if you buy something with an HDMI connector. For example, HDMI televisions will display video received from existing DVI-equipped products, while a HDMI DVD player will play on a DVI-equipped television. All you'll need is a HDMI/DVI adaptor.

Just be aware that doing this will lose you the added functionality of HDMI, such as automatic screen format conversion and universal remote control.
HDMI is still relatively new to the Australian market, so finding HDMI-enabled devices can be a difficult task. There are more and more HDMI products coming out every day, however, and they're not all high end gear.

On the display side of the equation, there are now several screens, projectors and DVD players to choose from. Toshiba, for example, have come out with a full range of home entertainment gear all sporting HDMI connections (check out our First Take of the HDMI enabled set top box). has long been a supporter of HDMI, with its plasmas some of the first to sport the new connector.

has also got in on the act, with its 50" plasma also sporting HDMI. recently released a DVD player with HDMI, while and also recently debuted two affordable projectors with the new connector.
Things are a bit bleaker when it comes to audio, though.

There are very few receivers that support HDMI, which means that to get full surround sound from your HDMI-enabled DVD player, you'll still need to plug audio in via a separate audio cable (such as a digital optical or coaxial).
If you're lucky enough to own a component with HDMI but don't have a cable for it, then there are several cable manufacturers now who sell HDMI gear. , for example, sell HDMI cables and HDMI to DVI cables under their Pure AV range of interconnects.

also has a comprehensive selection of HDMI products. HDMI cables and adapters by Monster Cable have been developed in a joint partnership with HDMI's founder, Silicon Image. Don't expect these cables to be too cheap, though: as with any new technology, it starts off pricey before eventually coming down.

As a standard, HDMI has the backing of companies such as Hitachi, Panasonic, Philips, Sony, Thomson and Toshiba. With such heavyweights behind it, coupled with the fact that HDMI is fairly inexpensive to integrate into devices from a manufacturing point of view, it's likely that the numbers of HDMI products coming to market will increase significantly
That's the future: for now, HDMI is stymied by a serious lack of products currently available. While more video products are coming out with HDMI, consumers will need to wait before gear such as receivers start supporting it from an audio point of view before HDMI becomes a fixture in all of our living rooms.