Silicon Image debuts new DVI chip for uncompressed HD
Silicon Image, a Sunnyvale, CA-based chip developer has introduced new silicon that it says is the first to add audio capability to the Digital Visual Interface (DVI) connection standard, expanding the market for uncompressed high definition video.
The SiI 190 PanelLink transmitter and SiI 991PanelLink receivers couple digital audio and video data in a single, secure, all-digital interface capable of supporting uncompressed HD content. The SiI 190 transmitter is designed for an array of consumer electronics host devices, including set-top boxes, DVD players, D-VHS players and game consoles, while the SiI 991 receiver is compatible with CRT, LCD, plasma and DLP-based HDTVs and projectors.
DVI is an alternative digital interface to the more popular 1394 or "firewire" standard that has been widely seen as the preferred connection between digital devices. Developed by the Digital Display Working Group (DDWG), a consortium of PC manufacturers including Intel, Compaq and HP, DVI is more popular among PC advocates and is touted for its ability to quickly transmit uncompressed video between devices. However, the standard is unable to transmit compressed video and with MPEG-2 as the standard for DTV, the standard faces an uphill battle in its quest for acceptance among DTV manufacturers.
Nevertheless, Microsoft and consumer electronics giants JVC and Samsung have come out in support for DVI as a preferred interface because of its content security scheme, known as High-Bandwidth Digital Content Protection (HDCP). EchoStar is also a fan of DVI.
"DVI with High-bandwidth Digital Content Protection (HDCP) will be a key component in future high-definition set-top boxes that implement advanced features," says Dave Kummer, VP of Engineering for EchoStar. "Furthermore, since we first became aware of DVI and HDCP, we believe the ability to transmit and receive digital audio data over the same uncompressed digital link as the video data would make the solution even more robust. EchoStar is pleased to know that Silicon Image is addressing this need, and we are excited at the prospect of offering integrated digital audio functionality over the DVI link to our customers in the future."
Audio adds functionality
Building upon the recent availability of HDCP, audio adds yet another layer of functionality to the robust, high-bandwidth DVI link. DVI with HDCP enables the encryption of premium HD video between digital CE host and display devices, addressing the motion picture industry's concerns about unauthorized duplication and piracy of their most valuable copyrighted content.
With the addition of audio capability to the same DVI link, CE manufacturers can now transmit and receive all digital surround-sound formats, including Dolby Digital, Digital Theater Systems (DTS) and PCM Stereo, while eliminating the need for a separate audio connector and cables. No additional pins are used as the audio data is embedded within the existing DVI clock channel with an advanced method of data modulation developed by Silicon Image.
By reducing the number of system components, embedded audio simplifies OEM system design, lowers component costs and improves ease of use for the consumer.
Martin Reynolds, vice president and research fellow for Gartner Dataquest, noted, "Even with today's near-gigabit interfaces, consumer digital AV interconnects require the use of compression. Compressed data drives built-in obsolescence in the display, or a messy and expensive external decoder. Neither is a satisfactory solution for the consumer, who requires a single connection that carries all audio and video between devices and long life of the expensive display subsystem. Also, the interconnect must be encrypted end-to-end to encourage the release of high-definition content, a real challenge to analog solutions."
Support from major studios
Constituencies responsible for the widespread release and availability of premium HD content in the home have already indicated their support for DVI with HDCP, including Warner Bros., Disney, Universal Studios and Fox.
"Audio strengthens the existing case for DVI as the digital interface for the critical connection between digital host devices and digital TVs," says Steve Tirado, COO for Silicon Image. "HDCP offers the promise of the highest quality video available, and DVI is the only digital interface with enough bandwidth to accommodate it. In addition, DVI is simple and cost-effective to implement in terms of both software and hardware because it's a point-to-point interface, unlike IEEE 1394."
Bandwidth of 2.2 Gigabits/sec. is required to support uncompressed HD video transmission. With bandwidth of up to 5 Gbps for a single DVI link, compared to the 400 Megabits/sec. supported by IEEE 1394, DVI is the only digital interface capable of accommodating uncompressed digital data such as HD video. Data transmitted in compressed format must first be compressed by the host device and subsequently decompressed by the HDTV upon receipt. This poses several problems, according to Silicon Image.
First, the compression and decompression sequence degrades image quality. Second, it requires additional components in both the host and display device, namely an MPEG encoder and decoder, respectively. DVI eliminates the need for these costly components, Silicon Image notes.
Additionally, DVI has excess bandwidth to support additional functionality beyond audio and HDCP that may be added in the future, again reducing the need for additional connectors. DVI also has the bandwidth to support higher audio fidelity, such as more channels of surround sound or 96 KHz sampling rates, as well as higher video resolution such as 1080p-ensuring no risk of long-term obsolescence.
The SiI 190 transmitter and SiI 991 receiver are projected to be sampling in Q2 2001 and begin shipping in production volumes during Q3 2001.
Source: Silicon Image
With contributions by Tom Butts, Managing Editor