Serial Digital

Recently, it seems, an update to Apple computers with a DisplayPort or Mini DisplayPort interface (that’s MacBook, MacBook Pro, Mac Mini, Imac, and Mac Pro machines) has caused HDCP to activate whenever the devices are connected to an HDCP compatible device.

What this means, for example, is that if you connect a MacBook Pro to a D/A (splitter) that supports HDCP, the copy protection standard will activate. Which is fine – as long as everything else in the chain also supports HDCP. In many cases, devices after the D/A will include things like Barco Encore or ScreenPRO II devices – which do not support HDCP – and will therefore see sync, but a black screen, or sometimes a ‘snow’ effect (a result of the raw encrypted signal).

I you connect a Mac using a DisplayPort to DVI adaptor to a device that does not support HDCP – for instance, directly into the background input of a ScreenPRO II, or into an ImagePRO HD, HDCP will not activate from the Mac, and the signal will flow through correctly.

HDCP is designed to prevent piracy – if you wish to play back a Blu-ray disc or copy-protected movie, the player (or computer) that it is connected to must support HDCP, and each display device connected to the player (or computer) must either also support HDCP, or be disabled. This is inherent to the HDCP (and DisplayPort) specification, and cannot be circumvented under license. HOWEVER, as Apple has done – they can prevent Blu-ray or copy-protected movies from playing back when non-compliant hardware is connected, but still allow that hardware to display other content (for example, a Keynote presentation).

At this stage, the Apple hardware is a little too smart for its own good – choosing to activate or disable HDCP depending on the first device connected to the Mac being either HDCP compliant or not. What we really need is a work-around to disable HDCP support on demand, which will mean we can connect it to an HDCP compliant D/A (or a unit like the Barco DCS-200), and still support other equipment further down-stream which is not HDCP compliant – in exchange for disabling playback of Blu-ray discs or copy-protected movies (which is typically fine for AV applications).

Work-around: For the time being, a slightly expensive work-around is to connect the Mac to an ImagePRO HD, and then take either/or both the DVI out, and DVI loop-out ports to connect to other equipment (HDCP compliant or not).

If anyone comes across a ‘hack’ for OS X or new Apple hardware that will disable HDCP support for the sake of connecting to AV equipment (and also maintains legitimacy by disabling Blu-ray and copy-protected movie playback), we’d all be grateful if you could leave a comment here or let us know so we can spread the word!