My HDMI Conundrum
Columnist John Caldwell says HDMI is great in theory, but the technology isn't where it needs to be.
Mar. 23, 2007 — by John Caldwell
I really want to believe in High-Definition Multimedia Interface (HDMI). I really do.
Uncompressed digital streams, unified component interoperability, and a reduction in the bird’s nest of cables that make up A/V systems are all things that warm hearts of custom designers, installers and high performance enthusiasts. But based on my experience and the horror stories I hear everyday from countless custom installers around the world, all is not well.
The problems with HDMI are numerous and have to do primarily with technical factors revolving around Digital Rights Management (DRM), High-bandwidth Digital Content Protection (HDCP) specifications, and something you’re going to be hearing a lot more about in the next few years: Image Constraint Tokens.
What prompted my rant this week is the simple act of taking the HDMI output from one HD DVD player and sending its video signal to two displays: in this case two high-def video projectors. This had me and a bunch of industry vets flummoxed last weekend while at the Electronic House Expo (Disclosure: EHX is run by ElectronicHouse.com’s parent company, EH Publishing).
We tried using a couple of different HDMI splitters from Gefen—one of the growing number of cottage industry suppliers making little “black boxes” for just such a common application. But alas, our plan for a really cool but simple side-by-side demo of 720p vs 1080p projectors went down in flames. Even the guys from Gefen couldn’t figure it out. We could get one side of the splitter to work, but not the other simultaneously. We could reverse the whole set up and get the other side to work but not the first. Uff dah! So we resorted to using two identical sources with two of the same HD DVDs to do the comparison. The horror.
This type of application should be routine; one that theoretically should take place in millions of homes everyday with one HD DVD player and two plasmas or one plasma and one projector.
My inability to make this simple distribution of one HDMI signal to two outputs is backed by the frustration I often hear from installers. So what’s an installer to do? Well, they run old-school analog component video cables and hope for the best. But the dirty little secret is that their clients see something that looks like an HD picture, but it’s certainly not as good as it can be. And once Image Constraint Tokens are switched on in 2010 or 2012 (they’re already inside many new DVD players, waiting like little time bombs) then these unfortunate consumers are likely to be receiving an even lower down-rezed picture.
I’m also disappointed with the HDMI connector. Unlike DVI cables that connect sources to computer monitors and projectors with lock-down thumb screws, the current HDMI connector design for A/V use has no such provision. It can easily be knocked out or fall out of its socket when you don’t plan for adequate strain relief.
In addition, there are no A/V preamp processors or A/V receivers on the market that can adequately switch and route the full capability of the current version of HDMI (1.3). Could it be that the manufacturers are having the same problem I ran into last weekend?
With HDMI 1.3, the HDMI cable carries full high-def video, full bandwidth multi-channel audio, as well as command sets and low-voltage power for sources. HDMI 1.3 supports output of Dolby TrueHD and DTS-HD Master Audio streams for external decoding by A/V receivers. TrueHD and DTS-HD are lossless audio codec formats used on HD DVDs and Blu-ray discs.
While there were all sorts of announcements made by suppliers last year about being able to finally switch to HDMI 1.3, there hasn’t been any appreciable deliveries as of yet. And that has system designers hurrying up and waiting. So I ask again: What’s an installer to do? None that I’ve spoken to feel like they can trust HDMI for anything more than direct from source to display video connections right now. Audio connections for the foreseeable future will remain in the analog cable domain for multi-channel HD audio and digital coaxial or toslink fiber for DVD and TV audio. This keeps the cost and installation complexity of A/V and home theater higher than it needs to be—and it’s keeping more people from enjoying this wonderful technology.
The current state of HDMI puts dealers and designers in the unfortunate situation of either knowingly or unknowingly delivering less than what the client paid for. Neither is good. So make sure you are doing business with a professional who knows that the compromises he may have to make to get your system up and running today aren’t forgotten about once this whole transition to HDMI gets sorted out.
Arm yourself with knowledge, but certainly don’t wait to buy. There’s too much fun and entertainment that awaits you.
Good listening and viewing!
John Caldwell is a 28-year grizzled veteran of the A/V business
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and co-founder of StJohn Group, Inc.