As the VGA connector continues its rapid transition towards obsolescence (referred to in Part I of this post) many people simply assume that using adapters (such as HDMI to VGA) will solve the digital-to-analog connectivity problem. While this may work in the short term, it ignores the looming problem of DRM (Digital Rights Management), a way of encrypting new media to protect against copyright infringement. DRM uses something called HDCP (High Bandwidth Digital Content Protection) to control which devices are allowed to receive the video signal. So how will you know if you’re using digitally protected content? Well, for starters, your adapter will just stop working.

Here’s how it works. A Blu-ray player or a computer with a digital output is connected to a digital display (like a computer monitor or a digital projector). The display sends a signal called EDID (Extended Display Identification Data) to the player to determine what resolutions and content protection to use. After a “brief” exchange of data, they work out the best signal based on both the player’s and the display’s available resolutions. When an HDCP protected disc is inserted into the player, the player asks the display for a “key” (a key is a number that allows the device to receive the protected content). The player determines that the display has an appropriate key and releases the encrypted video signal. As long as the key stays in place, the video can be sent. If anything interrupts the key (like a distribution amplifier, signal splitter, or adapter) the signal stops or never even starts!

In a home theater, where we are connecting a single Blu-ray player to a single flat screen display, this may work very effectively. But in the world of large scale Audio-Visual system design, we commonly want to send signals to numerous and varied displays. Digital signage systems in theaters, retails stores, and church lobbies send the same content to multiple displays. Auditoriums and arenas normally have more than one video screen for audience viewing (not to mention things like preview monitors for the production staff). Corporate Board rooms routinely send information to multiple displays in the main room as well as sending content offsite during video conferences. If your content source (like a computer) has a limited number of keys to use, what will you do if you’re one short? This is the real problem.

The writing is on the wall here my friends. The entertainment industry is pushing for all new media to be digitally encrypted with HDCP. While this can be a real positive advancement for movie studios and record labels (because it helps protect their copyrights), it can be a real headache for the rest of us.

Many of the organizations we work with (theatres, schools, churches, hospitals, etc.) have a heavy investment in their display technology, and they cannot afford to scrap their entire AV systems. Even if they can afford a new system, they’re afraid that the new one will quickly become obsolete by the newest and latest and greatest. While no one can design a “100% future-proof” AV system, we can adapt to the technology around us, making the right decisions for complex AV problems. And that’s why we’re here, to help make the connection.

ABD Engineering and Design

ABD Engineering and Design is one of North America’s leading independent acoustical consulting and AV design firms, serving clients across the United States and Canada, as well as other international markets from offices in Grand Rapids, MI and Portland, OR. Our specialized acoustical engineering and AV design practices help architects, building owners, engineers, facility directors, and municipalities design spaces, environments, and systems for optimal acoustical and audiovisual performance. Our consulting practice areas specialize in all aspects of architectural acoustics, environmental and industrial noise and vibration control, and audiovisual systems design.

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