Back to March 2013 ITS Newsletter

High Bandwidth Digital Content Protection

By Tim Hicks

HDCP?  Analog Sunset?  EDID? How these will affect your presentations?

High-bandwidth Digital Content Protection (HDCP) commonly, though incorrectly, referred to as High-Definition Copy(right) Protection is designed  to prevent the copying of digital video and audio content.  The projection system will stop HDCP encrypted material from being played on unauthorized devices and devices designed to make a duplication of the material.  Playback devices such as cable boxes, DVD decks, Blu-ray decks and more importantly computer video cards are HDCP compliant and are programmed to exchange "a handshake" between their output and the display device. 

Ok, what’s the big deal?

Let’s say you created a presentation on your laptop with a video clip embedded in the presentation.  You plug your laptop into the presentation system (a podium cable cubby or a portable projector), start the presentation and everything is working fine. Until you attempt to view the video clip. Then the projector goes to static or you see a message that says you do not have the rights to display this video. 

My embedded video in my PowerPoint presentation doesn't work!!

It was working fine in your office, why not now?  Your laptop knows you’re displaying the image on two devices, the laptop screen and the projector.  Your presentation may only contain 30 seconds of video, well within the fair use guidelines for educational use, but HDCP does not measure the length of the movie clip; it does not care if it is 10 seconds or two hours and it will disable the output.

In the short term, it is possible to bypass HDCP issues by hooking up your laptop with the analog (VGA) output rather than the digital (Mini Display port, HDMI) output.  Your image will be of lower quality but at least it will play.  This brings us to part two, the quickly approaching analog sunset. 

Analog Sunset

Analog Sunset refers to the demise of analog connections by 2015. VGA, component and composite video (the red, white and yellow connectors) on laptops, Blu-ray players, LCD screens, switchers and projectors will soon be gone.  We will no longer have the option to view material at this lower resolution because the industry will be removing the connections, forcing us to use the digital outputs and thus having to work within the HDCP standards.


If you’re thinking you’ll just keep your old laptop with its good old VGA output that works, I’m sorry to say that the needed Extended Display Identification Data (EDID) handshake will make this a problem.

Extended Display Identification Data

Extended Display Identification Data (EDID) is designed to enable a digital device to know what kind of display is connected to it in order to supply the best possible resolution.  As helpful as EDID is designed to be, if for some reason the projection system does not receive or provide the EDID information, then the signal is shut down and you have no display.

So what does this really mean for you?  Hamilton has over 120 projection systems in classrooms, conference rooms, labs, studios, and public spaces. Some of these are eight years old while others are just a few months old.  A person trying to connect a brand new laptop to the eight year old system in your lab will most likely not have the VGA signal the system requires.  Similarly, a guest presenter with a five year old laptop trying to connect to a brand new system will likely have trouble. 

What are we doing?

ITS and Audiovisual Services are working hard to make the transition into the digital world as smooth as possible.  For the next few years as the industry moves to all digital display outputs, we will be updating the TE classroom systems.  We will keep the analog cables in the cable cubbies for the foreseeable future and add the choice of an HDMI (High Definition Multimedia Interface) cable. In the meantime, if you have any questions about these changes, we encourage you to call us at x4120.

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