High Definition Television
High Definition Television (HDTV) promises a revolution in the delivery of television to our homes. With large plasma and LCD screens becoming more affordable, HDTV will provide us with the quality of picture that a large screen requires.
Most people will understand resolution in accordance with their computer monitor settings. An 800x600 screen contains 800 pixels (small spots of colour) horizontally, and 600 pixels displaying vertically.
The lowest resolution that anybody uses on their computer screen is 640x480 pixels, with most users setting their resolution at 1024x768 pixels.
Standard television suffers in comparison to this level of detail. A normal UK television screen will utilize just 720x576 pixels. The bigger the screen, the more these pixels are stretched, resulting in poor picture quality, or definition.
HDTV is set to change all that. HDTV is high-resolution digital television (DTV) combined with Dolby Digital surround sound (AC-3). This combination creates a stunning image with stunning sound.
Production Requirements
HDTV requires new production and transmission equipment at the producer’s end, as well as new equipment for reception by the consumer.
Unfortunately for the producers, this means some serious investment in new equipment that is capable of producing Hi-Def content. Many lower end semi-professional cameras are already capable of filming in Hi-Def, but editing and production equipment needs to be upgraded.
The main problem with the Hi-Def format is that more pixels means bigger file sizes. For example, a one-minute clip encoded at 720p = 49MB. The same clip encoded at 1080p will require 63MB of storage space.
These large file sizes require huge storage devices and fast transfer to ensure smooth production.
The formats used in HDTV are:
· 720p – 1280x720 pixels progressive
· 1080i – 1920x1080 pixels interlaced
· 1080p – 1920x1080 pixels progressive
"Interlaced" or "progressive" refers to the scanning system. In an interlaced format, the screen shows every odd line at one scan of the screen, and then follows that up with the even lines in a second scan. Since there are 30 frames shown per second, the screen shows one half of the frame every sixtieth of a second. For smaller screens, this is less noticeable. As screens get larger, the problem with interlacing is flicker.
Progressive scanning shows the whole picture, every line in one showing, every sixtieth of a second. This provides for a much smoother picture, but uses slightly more bandwidth.
Mpeg-2
MPEG-2 is the format in which Hi-Def content is produced. The use of MPEG-2 permits an HDTV receiver to interact with computer multimedia applications directly. For example, an HDTV show could be recorded on a multimedia computer, and CD-ROM applications could be played on HDTV systems. A digital TV decodes the MPEG-2 signal and displays it just as a computer monitor does, giving it high resolution and stability.
Hi-Def DVD players are practically nonexistent in the UK. Apart from subscription-only foreign satellite stations, the only way to experience HD content is via your PC.
Many HDTV sets have inputs that allow the user to plug their PC into the back of the television. In the UK, this is currently the only free way to access HDTV content.
PC requirements
Hi-Def content will not play on any old PC. The minimum requirements are as follows:
Minimum configuration
(to play 720p video)
· Windows XP
· Windows Media Player 9 Series / DivX player
· 2.4GHz processor or equivalent
· 384MB of RAM
· 64MB video card
· DVD drive
· 1024x768 screen resolution
· 16-bit sound card
· speakers
Optimum configuration
(to play 1080p video with 5.1 surround sound)
· Windows XP
· Windows Media Player 9 Series / Div X Player
· DirectX 9.0
· 3.0GHz processor or equivalent
· 512MB of RAM
· 128MB video card
· DVD drive
· 1920x1440 screen resolution
· 24-bit 96kHz multichannel sound card
· 5.1 surround sound speaker system
Media Center PCs
Media Center PCs are the first glimpse into the future of home media convergence. Instead of a separate DVD player, recorder, freeview box, CD player, MP3 player, image viewer etc., the media center provides all of these formats in a single box. Often it doesn’t even look like a PC, but more like a traditional set-top box.
Powered by Windows XP Media Center Edition, Media Center PCs are complete Windows XP PCs enhanced for home entertainment. These computers represent the evolution of home PCs into digital media hubs that bring together your entertainment choices and let you access them with one remote control. Media Center PCs come equipped with all the necessary hardware to deliver powerful computing and an enjoyable home entertainment experience (www.wmvhd.com).
Content
There is currently very little content available for Hi-Def users. If you have purchased an HD-ready television set, you will be disappointed to discover that TV stations are yet to broadcast Hi-Def content, and that a format-war, akin to the old VHS/Beta dispute, is raging across the world.
Format Wars: Hd-Dvd V Blu Ray
The two formats fighting for supremacy as the next-generation videodisc format are HD-DVD (developed by Toshiba and NEC) and Blu-ray (developed by Sony).
Blu-ray has Sony-owned Columbia Tri-Star behind them; adding to this powerhouse, Sony just bought MGM. Twentieth Century Fox and Disney have also committed themselves to Blu-ray, although a high-ranking executive at Disney has said that they still aspire to and would argue for a unified format. HD-DVD is backed by Time Warner (Warner Bros., HBO and New Line), Universal (DreamWorks) and Paramount. At the 2005 Consumer Electronics Show in Las Vegas, the HD-DVD camp announced that they will be releasing a slew of titles on HD-DVD before the year's end, including Batman Begins, Braveheart and the Harry Potter series. However, the launch has now been delayed until February or March 2006.
Both formats look strong and, sadly, it looks like a format war is unavoidable. But a war can be tough on the success of high-definition content on DVD and may create hesitation on the part of consumers eager to invest in it. (See www.hdtv.org).
But even then, it isn’t as straightforward as it seems. Some experts are predicting that the two formats above will be superseded within five years by even more advanced DVD technology, which has been in development for several years. This revolutionary technology promises to deliver profound advances in data storage, allowing up to 10 TBytes of data to be stored on a CD-sized disk – over 2,000 times more than current DVDs allow.
Holographic Data Storage (HDS), as it is known, is predicted to become the next-generation storage technology beyond CDs, DVDs and other conventional optical storage technologies. It promises to offer the ability to store up to 10 TBytes on a standard 120mm disc, with read/write speeds in excess of 6Gb/sec and access time in the order of microseconds.
Current work on media using existing materials and technologies continues to suffer from a number of weaknesses, including low sensitivity and instability. The developers of HDS believe that this revolutionary medium will solve these problems and they are seeking a drive-manufacturing partner to roll it out in a commercial system.
Upscaling
Currently the best way for users to utilise their large plasma/LCD screens is through upscaling. This is a process that mathematically matches the pixel count of the output of a standard or non-Hi-Def signal (such as standard DVD) to the physical pixel count on an HDTV, which is typically 1280x720 (720p) or 1920x1080 (1080i). Put simply, the “upscaling” DVD player fills in the gap between pixels that will occur when you try to stretch a picture too thinly over a large screen. It isn’t perfect, but until genuine high-definition players and content arrives, it’s the best solution.
The only content available to the early adopters keen to utilise their new systems are video trailers and amateur films made available on the following websites:
http://www.wmvhd.com
www.divx.com
The Broadcasting Future
Sky TV recently announced that they expect to offer an HDTV subscription service early in 2006. Initially it appears that this will be very expensive, at several hundred pounds for a Sky HD box, plus a monthly subscription fee.
The BBC has announced that it will broadcast some programmes in high definition, but you will still need a HD decoder, such as the Sky HD box, in order to view it.
An opportunity?
It would seem that anybody who would be prepared to offer high-quality, high-definition content online would be guaranteed an enthusiastic audience worldwide. There is a very small window of opportunity here to create huge worldwide interest in any production that has the resources to offer enough bandwidth for downloadable content.