HDMI cable
HDMI is an acronym for High-Definition Multimedia Interface. Version 1.0 of the HDMI specification was released in December of 2002, followed by version 1.1 in May of 2004. Like the DVI spec, there are both single and dual link version of HDMI. The single link version is known as “Type A” and the dual link version is “Type B”. At the time of this writing, Type B has been defined, but I have not seen any equipment or cables that support it. So for practical purposes, HDMI Type A is the only one that we need to be concerned with at this time.
Like DVI single link, HDMI Type A supports video pixel rates up to 165 MHz. The spec was designed with HDTV in mind, so naturally, it supports all HDTV video formats up to 1080p. In addition, up to eight digital audio channels are supported.
Because only one flavor is currently in use, compatibility is very simple. If have two HDMI-enabled components, any HDMI cable can be used to connect them.
In addition, HDMI Type A is compatible with DVI-D single link using simple passive adapters and conversion cables, with the understanding that the special features of each format are not supported in the other. For example, an HDMI to DVI connection will not support HDMI digital audio. Likewise, a DVI to HDMI connection will not support analog video. DVI and HDMI accessories, such as switchers and splitters are compatible in the same way. For the purposes of digital video, the two interfaces are functionally identical.
The maximum length for a “standard” HDMI cable approaches 15 meters, although I would comment that “standard” cables do not work with all equipment combinations. Fortunately, high-performance cables are available, and 15 meters (49.2 feet) is easily attained with good cables. For very long runs, a CAT5 or optical extender can be used. The one caveat here would be in the case of DVI/HDMI conversion cables. DVI is more sensitive to distance than HDMI, so a 15 meter DVI cable must be much better than a 15 meter HDMI cable in order to accomplish the same goal. As such, long cable runs should be considered from a DVI perspective. If the cable is good enough to handle a DVI connection, then it will easily handle HDMI over that same distance.
