Thursday, July 23, 2009

HDMI to DVI? to VGA?

HDMI or High Definition Multimedia Interface, developed to transmit high-quality sound and picture over one cable, has rapidly become the standard for digital TVs. Brand-new TVs and home theater components usually have HDMI – but since the technology is so new, you probably own electronic audio/video gadgets that don’t have it.
Going from the present back, back in time: HDMI is digital. DVI is sort of a compromise. VGA is analog. (And if, like me, you remember black-and-white TV and three channels, you are a dinosaur. Hold the HDMI cable in your hand and repeat after me, “Wow. High definition video and eight channels of audio transmitted on this little cable.”)
Of course you want to use your old equipment with your new equipment.
I needed to use HDMI output from a new computer to run a projector, which had only VGA and DVI inputs. This one was easy – there’s a cable you can buy which goes from HDMI to DVI. That gets you a picture with DVI.
On the other hand, if I want to use a projector, monitor, or television that only has VGA, there’s a much bigger gap to bridge. I have a humongous high-def projection television in my family room with only VGA input. An ordinary converter cable won’t work.
The problem here is that HDMI includes a technology called HDCP, High-Bandwidth Digital Content Protection. This security scheme (which is either a copy protection strategy or simply to ensure high-quality content, a matter of opinion) uses special information that gets passed between the sending device and the receiving device. If the video-sending, HDMI equipped gadget doesn’t receive that signal, all you’ll get for your trouble is a black screen on your television, monitor, or projector. To send pictures from HDMI to your VGA equipment, you need a special powered converter and appropriate cables.
One that I saw, doing some searches, is the HD Fury, about $140 (no affiliation).

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