You may think your brand-new Full HD TV looks good, but the future looks way, way better. It’s called 4K, looks like 35mm cinema, and is five times the resolution of 1,920 x 1,080.
TV is on the move again – with a new ultra-high definition format on the horizon. At this year’s Consumer Electronics Show in Las Vegas, several TV makers had proof-of-concept TVs supporting the next-generation content standard known as 4K. Named after an image with horizontal resolutions of up to 4,096 columns and 3,112 rows, 4K is the heir apparent to today's 1,920 x 1,080 HD content – approximating the detail of a 35mm cinema print.
Indeed, 4K sources have a genesis in commercial film production: extant digital-film and post-production standards offer four working resolutions, each with different aspect ratios. The highest, Full Aperture 4K, offers a 12.7MP image with a 1.32:1 ratio while Academy 4K (3,656 x 2,664) comprises 9.7MP at 1.37:1. Also on the roster is Digital Cinema 4K, at 4,096 x 1 714 (7MP at 2.39:1) or 3,996 x 2 160 (8.6MP at 1.85:1).
Little wonder the sets were being marketed at CES using terms like LG's 'ultra definition', which was used to describe an 84in monster offering pictures at up to 4K's 12.7MP. LG and Sharp are expecting to have 4K sets on the market later this year, although there's no indication yet on Australian availability – and most major electronics makers offer at least one monitor or projector that supports 4K.
4K video standards
Rolling out 4K ultra-high definition won’t be a trivial exercise. Apart from new TV sets, you need new cameras and different video recording formats and codecs to shoot and store the video. Raw footage shot in 4K produces big, big files: Sony's new F65 4K camcorder, which costs $US65,000, records around 17GB of uncompressed video per minute – that extant Blu-ray discs will struggle to carry content of meaningful length. Professionals shooting 4K video can only cram a few minutes' worth of footage onto an 8GB memory card, so it's easy to appreciate how rarefied the whole process is.
Producers of 4K content typically capture it as DPX (Digital Picture Exchange), a high-resolution, open ANSI standard (268M-2003) that's used to record 4K master files. Each DPX file – of which a two-hour motion picture requires 172,800 – stores a single image as a range of RGB, luma or chrominance-luminance data as well as a broad range of detailed metadata relevant to television or motion-picture broadcast. Sound is recorded and managed separately.
As with HD content, trade-offs between bandwidth and connection speed will determine the accessibility of 4K content for some time: a future 100Mbit/s national broadband network-based internet service, for example, could quite happily stream 4K video in real time – as long as the content host was able to push out data to multiple subscribers fast enough. And, for now, that's a big 'if'.
The content paradox
File sizes aren't the only thing complicating the 4K TV market; the shift towards 4K presents a paradox for TV makers, who face very real manufacturing constraints in delivering units that can make such high resolutions worthwhile.
New organic LED (OLED) HD TVs, which TV makers are pushing as the biggest short-term advance in TV technology, are so sharp already that cramming more pixels into average 42 and 50in panels isn't necessarily going to improve the overall viewing experience markedly. A 4K picture would of course shine on the likes of LG's 84in demonstrator or Panasonic's 152in proof of concept TH-152UX1 4K monitor – which debuted with a price tag of around $500,000 but has come down in the interim – yet such units are hardly mainstream purchases.
For consumers wanting the higher resolution, projectors may in fact become a popular display method because they can project the images at the massive sizes that make 4K shine, without the price tag of a panel-based TV. As manufacturing methods improve and TV makers look to differentiate their products with ever-larger screens, however, 4K compatibility is likely to become a bragging-rights feature in high-end flat panels.
Whatever devices consumers buy, there is virtually no 4K content available to display on them. Indeed, even HD content is still relatively rare in Australia, where free-to-air TV has scaled back its HD broadcasts and major sporting events are still broadcast in standard definition.
"As a commercial entity, you do start to come into issues in terms of having bandwidth and media able to deliver the file sizes that are necessary for 4K," says Brad Wright, national sales and marketing manager for AV with Samsung Electronics Australia. "The technical capabilities are there, but we're still a very long way from there being content that can really showcase the technology."
Even if 4K can trickle into the mass market – a process that this year's CES demonstrations were designed to kick off – it will be years before content producers get up to speed. That will restrict the technology to pre-recorded content delivered as streaming media from the likes of YouTube – which already allows 4K-resolution uploads.
In the shorter term, early 4K adopters may get the biggest benefit not from sourcing 4K-only content, but from using crossover devices that use up-scaling techniques to boost existing content to the new resolution. For these purposes, expect widespread usage of QFHD (Quad Full High Definition), another standard that offers 3,840 x 2,160 pixels – twice the horizontal and vertical resolution of 1080p HD, which makes it an easy target for scaling existing 1080p content. Sony and others are already developing up-scaling Blu-ray players that intelligently analyse a 1080p stream to produce 4K output – and may be out later this year.
