High definition video is the next big thing for Australia. We explain the essential technologies for your TV or living room PC, and what to expect from our broadcasters.
The expectation has been building for years, the TV sets continue to be heavily promoted in stores, and now Australia’s major free-to-air broadcasters are sending next generation television over the airwaves. That is, of course, a very simple summary of what is becoming one of Australia’s biggest technological revolutions. This feature looks at the technology, the complexity and the politics – and why your PC is at the centre of it all.
If you’ve not seen HD video in action, there’s no written description that can bring the technology to life – you just have to experience it. Increasing the resolution to 1280 x 720 or 1920 x 1080 (the two standard HDTV formats) unleashes some major enhancements: the image looks clearer and brighter; colour gradations are smoother and more realistic; you can see more intricate forms or textures. The image looks both more lifelike and more cinematic. Some compare it to looking out of a clean window, but here’s something easier to grasp – it’s like comparing an image taken with a 1-megapixel digital camera to an image taken by a 2- or 4-megapixel model. You’re getting between double and four times the detail.
And, in theory, the PC is perfectly equipped for this. Most of us have displays capable of a 720p image (more on this later), even if we use a 1280 x 1024 LCD monitor or a 1280 x 800 laptop. What’s more, HD content is already available, from downloadable demo clips to HD trailers on Apple’s QuickTime site. With the right software – Windows Media Player 10 or QuickTime 7 - we can enjoy video recorded in the H.264 and WMV 9 (Windows Media Video) HD formats, and most recent graphics cards from NVIDIA and ATI have listed H.264 acceleration among their features. Both HD-DVD and Blu-ray PC drives are on their way, and we even have HD digital video cameras capable of shooting 1080i resolutions. What’s more, Avid, Pinnacle and Ulead have produced HD editing software to match.
But HDTV, whether for your television or your PC-connected widescreen LCD, is a minefield, and there will be winners and losers from television’s HD revolution. From the recording studio, through the broadcast network and into your living room or study, every link in the chain must be ready.
The technology
As well as the tremendous increase in resolution, HDTV also promises a more stable image, and it’s important to be clear about the different terminology. The old CRT televisions were built to handle an interlaced picture, where the image was converted into two fields of odd and even lines that alternated 50 times per second, fooling the eye into perceiving a single 25fps image. The problem is that the eye isn’t that easily fooled – it notices the slight flicker, and registers unnatural motion. The 100Hz sets were designed to fix this, but the digital processing required often resulted in noticeable digital artefacts, particularly in sequences with lots of fast movement.
The LCD and plasma screens that make up the bulk of HDTV sets use a different system, called progressive scan. Here, the whole image is updated one frame at a time at a constant 25fps or 30fps. As a result, HDTV is designed to run in three formats: 720p (1280 x 720 pixels, progressive scan), 1080i (1920 x 1080, interlaced) or 1080p (1920 x 1080, progressive scan). It’s here where Australia differs controversially from the rest of the world, where the Digital Broadcasting Australia association states that the lesser 576p (720 x 576 progressive) standard also qualifies as high definition video.
Which you use will depend on first, your set, and second, the resolutions supported by your broadcaster or source equipment. Basic HDTV sets may support only a particular resolution; most current HDTV broadcasters in the US, for example, broadcast only in 720p or 1080i; the Xbox 360 games console outputs only 720p or 1080i, and the same goes for the next-generation HD DVD format; and in Australia, you’ll find 576p and 1080i. However, both the Blu-ray format and the PlayStation 3 console are expected to support 1080p. Perhaps that’s why Sony, which produces both, is so keen to describe 1080p as the true high-definition format.
Is the premium for a 1080p set worth paying? Well, while there’s some doubt about whether 1080i is an improvement over 720p – you have to trade off added detail for that interlace flicker – there’s little doubt that 1080p offers noticeable benefits, particularly if the screen goes above 40in or you’re sitting closer to it. That added detail and smooth playback add up to a very pleasurable experience.
The final key benefit is audio. Depending on your source, you can expect anything from 5.1 Dolby Digital (in the case of Channel Nine), or Dolby Digital 2.0. HDTV services are designed to work with a full 5.1 signal.