The interoperability of DTV and consumer electronics
Nov 5, 2006 8:00 AM
The latest rage in consumer electronics interconnectivity is the plug’n’play installation and configuration of displays, DVD players and other media sources made possible by HDMI (High Definition Multimedia Interface). Nearly 60 million consumer electronics devices sold this year will have HDMI capability, and the number is expected to grow to more than 250 million devices by 2009.
Even though a consumer electronics consortium developed the specification, professionals in the movie industry were the main motivators to include content protection in the HDMI standard. They were alarmed by the impact that peer-to-peer downloading and unauthorized file sharing had on the music industry, and were concerned about the extent of DVD pirating. As a result, creators and distributors sought a method to protect their rights. HDCP (High-bandwidth Digital Copy Protection), developed by Intel, has allayed the Motion Picture Association of America’s (MPAA) pirating concerns and is incorporated in the HDMI specification.
The concern then shifted to consumers who had already purchased HDTV displays without an HDMI interface. Producers and manufacturers wanted to switch over to these new standards, essentially ending analog distribution, but also wanted to avoid disenfranchising a loyal customer base. The solution was an agreement between the producers and manufacturers to delay analog shutoff until 2009, when HDMI will have penetrated the market enough to virtually eliminate the problem of component connectivity.
Bidirectional communicationBidirectional communication is at the core of HDMI technology. Information exchanged between sending and receiving devices minimizes the need for manual set up; this HMDI “handshake” should automatically negotiate video and audio formats. The information necessary to accomplish this is contained in the EDID (Extended Display Identification Data). The receiving device, usually a display, communicates its format capabilities to the sending device, and the content is sent in the specified format.
HDCP follows a multikey exchange algorithm used by many access control and rights management technologies that confirms authentication every two seconds. Because the authentication process happens so often, replacing a legal device with an illegal copying device is virtually impossible.
Home network connectivityDuring the next few years, as DTV receivers and display prices continue to drop, consumers will purchase smaller displays with HDMI capabilities to replace analog televisions throughout their homes. HDMI facilitates distribution of audio and video content to any of these viewing locations.
This is fine now, but as enhanced and interactive DTV data services become more prevalent, the latest HDMI 1.3 specification cannot support these advanced features. Because much of this information, such as program guides, is conveyed in the transport stream PSIP data packets, it is not available downstream from the STB or ATSC receiver.
A downstream HDMI-connected digital television is also not able to provide many iTV features, because this information is contained in transport stream ACAP (Advanced Common Application Platform) or OCAP (Open Cable Applications Platform) packets.
Unfortunately, this means that HDMI will not facilitate tomorrow's home digital network. Will this open the door for Internet-delivered television (IPTV)? All the technology is in place for home distribution using IP. With IP, one wire with sufficient bandwidth can deliver content and interactive features to every network-connected device.
| Want to use this article? Click here for options! |  |
