With producers of commercial content placing their material under protection, systems integrators have faced a frustrating challenge: what happens when the project design dictates the routing of multiple video sources to a number of different outputs?
The answer is, not much—unless you take the right measures. The playback of copyrighted video content requires HDCP (High Bandwidth Digital Content Protection) compliant routers, which themselves call for digital video in the form of HDMI (High Definition Multimedia Interface) or DVI (Digital Video Interface). With this technology, users can, for example, playback multiple DVDs to several displays for digital signage, entertainment, or exhibition applications, without risking degradation to the audio/video signals. The problem is, these digital video signals aren’t as easy to integrate as those that systems contractors have grown accustomed to working with, and there are a number of issues, including shorter transmission distances and different termination methods, that must be addressed.
Initially, HDCP was developed to support consumer applications, such as a residence featuring a satellite box, a DVD player, and a television. This limited the number of displays that could be connected to a single source. “You could connect one display to the source and everything would work,” explained Dan Jackson, marketing and development engineer at Crestron Electronics. “If you connected two displays to the source, the source would shut down and not transmit any of the content unless you disconnected one of the displays.”
Jackson’s colleague, vice president of technology Fred Bargetzi, illustrated a common scenario: an organization that wants to display headline news across four displays, with a satellite box that holds only two keys. “What will happen is, the first two displays will turn on, and when you go to route it to the third display, all of the displays will shut off,” he said.
HDCP requires each source to receive a key from each display that it’s going to; it verifies that the key is correct, that the display is valid, and only then will it show the content. If the source doesn’t receive the appropriate key, it won’t output anything.
RTcom USA has addressed these issues with the introduction of its HS-66M and HS-88M HDMI matrix routers, as well as the DS-66HM DVI router, all of which are HDCP compliant. The units allow for the transmission of high-definition audio and video signals from a number of different sources, such as AV receivers, satellite set top boxes, and Blu-ray disc players—up to six or eight different displays without signal degradation. “With our product, we are distributing that signal from the sources to the display to make sure that they are handshaking correctly,” explained Joon Ryu, president and CEO of RTcom. “The content protection is based on that handshake between the sources and displays so that they are communicating with each other, and if the signal is HDCP compliant, it will be displayed.”
Crestron has responded to the need for HDCP compliant systems with its DigitalMedia line, slated to ship soon. Aimed at the residential market, DigitalMedia is an HD AV distribution system that enables a number of AV sources to be routed from a centralized rack location, and supports a complete range of analog and digital signals through one switcher. Each signal remains in its native resolution and audio format to ensure that there are no losses along the signal path. The system also allows for the integration of media servers, computers, and video game consoles.
Morganville, New Jersey-based control systems manufacturer Aurora Multimedia’s video processor/scaler Dido is also capable of accepting HDCP content. Andy Fliss, vice president of sales and marketing, points out that because Dido is also a format converter, integrators must be careful about how the mix analog and digital signals. “It can take in analog or digital and output analog or digital, but if I put HDCP on the input of the device, all analog is shut down,” he explained. Take, for example, a system featuring five inputs (two of them being digital, two being analog) and two outputs: “If all of a sudden I introduce an HDCP source, I lose access to outputting those other sources. I can no longer output analog. With anybody who is compliant with HDCP licensing, it will shut down their analog ports as soon as there is a presence of an HDCP signal.”
Fliss noted that the reason for this is because the content protection is designed so that the output cannot be recorded. “Once we go to analog, it’s recordable,” he said.
Bargetzi acknowledged that while many integrators might prefer to continue working with analog, pretty soon, they will have no choice but to migrate over to digital. “The people that are driving the content are dictating the format that it’s going to come out on, and whether we like it or not, HDMI with HDCP is the standard.”