Your HDMI Cable Also Must Support 1080p
March 12, 2009

OK, so you paid more for your new 1080p HDTV to ensure you'll be able to view source programming actually delivered in 1080p at full high definition quality. Presumably you or your installer connected your HD source devices to the new TV using HDMI cables.

However, even if you are aware the lastest HDMI cable standard is governed by the 1.3a HDMI Specification, there are two categories specified. The Standard (Category 1) cable: supporting 480p, 720p, and 1080i or a frequency response up to 74 MHz., and the High-Speed (Category 2) cable: supporting 480p, 720p 1080i, 1080p/60, and 1080p/120 “Deep Color” or a frequency response up to 340 MHz. Note even more confusing is a 1.3b or 1.3c compliance only means the HDMI cable passed those testing specification levels, but may not actually be compliant with the 1.3a HDMI spec.

The translation of the above is: if you didn't use HDMI cables adhering to the 1.3a category 2 specification you may not be able to view a HD program in full 1080p format. Welcome to the club if you didn't know HDMI cables came in 2 flavors, Standard and High-Speed! But, you may be saved from your ignorance if the HDTV you bought compensates by boosting the standard HDMI signal to the high-speed level to achieve 1080p.

The fact is the HDMI 1.3a Specification has all types of goodies that will some day make connecting several HD sources to multiple HD displays or audio players possible by extending a single HDMI cable from device A to device B to device C and so forth by daisy-chaining the HD cables creating in effect a single HDMI buss. This "HDMI buss" will be able to carry more than just audio/video signals, but also control signals that will eliminate the need to use IR emitters for those devices being universally controlled by a single remote or integrated into a home automation system.

Well, when is that going to happen? Timing-wise we're not at all sure.

But these things must happen to the products involved to make this possible:

1. The universal remote or home controller must support an HDMI output to place the control signals on the HDMI buss and listen for a response.
2. A HDMI T-connector plugging into each A/V device HDMI port must be available to propagate the buss among all connected devices, or
3. Alternatively, each A/V device must provide a companion HDMI output for each HDMI input to allow the next cable to plug-in to extend the buss to the next HD device.
4. And, finally the firmware embedded in each A/V device must be upgraded to support the HDMI buss and react to the control signals sent over the buss.

Sounds like an interesting project for a capable engineer or two at each electronics company wishing to participate. Now don't you feel better about just having to worry about picking the right HDMI cable for now?

To review the High-Definition Multimedia Interface Specification Version 1.3a click here.