While high-definition television promises pin-sharp pictures of this summer’s soccer World Cup, the technology is also promising greater clarity and separation around the back of those widescreen displays.
HDMI – high-definition multimedia interface – is a simple connector that can reduce a tangle of cables at the back of a set to just one. The HDMI link carries digitised HD video and eight-channel audio combined, as well as providing a channel for other functions, such as reducing the number of remote controls needed to operate systems.
As always there are other standards and acronyms out there, but HDMI seems set to dominate high-definition transmission and avoid the kind of battle taking place in the same arena between Sony and Toshiba over Blu-Ray or HD-DVD – their rival high-definition DVD standards.
An alliance of companies is behind HDMI, but the prime mover is little-known Silicon Image, a semiconductor company founded in Silicon Valley a decade ago.
In 1999, Silicon Image sought to improve on the VGA (Video Graphics Adapter) connections that linked PCs and monitors through analogue-to-digital and digital-to-analogue conversions. It developed, in partnership with Intel, Compaq, HP, IBM, NEC and Fujitsu, the purely digital DVI (Digital Visual Interface) connections. DVI connectors are now available next to VGA ones on PCs, with 50 per cent penetration of the market achieved.
DVI also found favour with the movie industry for its ability to include high-bandwidth digital content protection (HDCP) that would encrypt data as it was transmitted, preventing movies from being intercepted and pirated.
The consumer electronics industry was also attracted by DVI, but wanted a smaller connector and support for audio – leading to Hitachi, Matsushita (Panasonic), Philips, Sony, Thomson and Toshiba teaming with Silicon Image in 2002 to create the HDMI standard.
HDMI offers uncompressed video and the latest version due by mid-2006 will offer uncompressed audio formats, higher speeds of more than 10 gigabits a second, “deep colour” capable of rendering more than 1bn colours and a new mini connector that will see its adoption on smaller devices such as camcorders and notebooks PCs. Panasonic will this year introduce a range of home theatre systems and DVD recorders that uses a control protocol in HDMI to allow playing a movie by pressing one button on a single remote, or turning off a whole system by pressing the off button on the TV.
A different solution put forward by the newly formed High-Definition Audio-Video Network Alliance (Hana) will also allow control of devices from a single remote. But Hana – with JVC, Mitsubishi, NBC Universal, Samsung and Sun Microsystems among its members – is focusing on networking high-definition content around the home to different devices, at first using coaxial cable and eventually relying on wireless technologies such as Ultra Wide Band (UWB). Hana is basing its solution on the IEEE 1394 or Firewire standard common in computers today that allows daisy-chaining of devices from different manufacturers.
Dick Sillman, chief technology officer for Sun’s Communications Media and Entertainment group, says Hana will help ensure interoperability between different HD devices. “HDMI is probably going to be the primary way that a receiver talks to a high-definition television, in a point-to-point connection, as opposed to a network where devices can announce their presence to other members [as they are plugged in],” he says.
But Steve Tirado, Silicon Image chief executive, says solutions based on software stacks, such as Hana’s and that of a similar grouping – the Digital Living Network Alliance – will introduce unwanted bugs and administration tasks.
“DLNA and Hana and a lot of these initiatives in the marketplace are trying to borrow from the IT world and then put that in the consumer electronics world. Our drive is to stay focused on very highly integrated semiconductor implementations,” he says.
HDMI already has a significant lead over six-months-old Hana with 300 companies adopting the standard and more than 1,000 devices in the market. Sony’s PlayStation 3 console, due this year, will have an HDMI connection. “I think HDMI is going to be the baseline universal digital interface,” says Gerry Kaufhold, analyst with the In-Stat research company.
“But a lot of TV sets will have other interfaces such as 1394 [Hana] and analogue component video – manufacturers can differentiate their systems by supporting these others as optional extras.”