HDMI 1.3 Certification - A Real Dilemma

So what's so special about certification? Nothing, if you're running a 3 foot HDMI from the DVD player to an LCD panel. Just about any old cable will do. However, if you are going to install a cable that is in danger of hitting upon the maximum potential of the format and you're putting that cable into a wall or ceiling - you might want to spend a little extra and buy from a company that guarantees and tests its products.

The interesting thing about certification, however, is that HDMI Licensing, LLC doesn't even account for the real-world situation where chip manufacturers don't fully support 3.4 Gbit/s bitrates. No one we know of supports the theoretical maximums. As a result, the real-world bit-rates of 2.2275 for 1080p at 12-bit color needs to be tested using the same criteria as the 1080i cable that only needs to pass 742.5 Mbit/s. That's right, there is currently no certification for 1080p at 12-bit. Are you scared? You should be.

So far, from what we understand, HDMI certification is largely a very fast and loose (not to mention expensive and apparently profitable) program that does nothing to truly ensure any of the manufacturer's production cables meet or exceed any practical current specification. Why do we say this? Simple. The HDMI testing standard has two categories currently:

• Category 1 is for 720p and 1080i cables at 8-bit color. This is the "chump change" spec that was business as usual before HDMI 1.3 and, unless the connectors fall off, any Chinese-made cable is going to hit this for at least 4-5 meters without a hiccup.
  
• Category 2 is the balls-to-the-wall 3.4 Gbit/s (non-existent) standard. The only silicone that exists on the market beyond Category 1 is rated to handle up to 2.25Gbit/s. For certification you either test level 1 (duh) or level 2 (meaning you must over-design your product.)
  

What the HDMI people should have done is inserted a real Category 2 certification for real-world 1080p/60 12-bit color (~2.25Gbit/s) since that bitrate is supported by silicon chipsets. "Category 3" could then take on the theoretical maximums of 3.4Gbit/s for future-ready products such as cables (since no electronics can pass the theoretical maximums at present).

Conclusion

So where does this all lead? To a grand new adventure. Progress is good, but HDMI v1.3 was a bit of an artificial "nudge" in a direction consumers didn't necessarily feel the need to take. Even so, I believe it will all work out on the end and it did allow cable manufacturers (the serious ones) to quickly realize the need for active solutions to ensure signal stability and integrity for longer cable runs. Without the increased bitrates this may have taken longer and more consumers would be installing cables that wouldn't pass the high bitrate signals now present in an ever-increasing amount of consumer electronics. The key to remember is that you cannot install an HDMI cable in your ceiling or wall that is designed to pass Category 1 specs (742.5 Mbit/s) and assume they will be just fine for features such as 1080p and 12-bit Deep Color. Pay attention and ask questions so that you aren't pulling your hair out down the line as you rip open your walls and curse your custom installer for letting you take the cheap way out!

Special thanks to Steven Barlow of DVIGear for technical contributions to this article.