HDMI’s Dirty Little Secret

By Gary Kayye, CTS

By now, you’ve probably all seen the HDMI connector (the connector standard for high-resolution HD-TV content) on something. It’s everywhere.

It’s on HD-DVD players, Blu-ray Disc players, HD DirecTV set-top boxes, Explorer 8300 HD Cable TV boxes, HD-flat panel TV’s, Sony’s PlayStation 3 – everywhere you see HD content.

But, it’s also on progressive-scan DVD player.

And, that’s where it sucks!

Look, unless you’re outputting HD content that’s truly digital and high-resolution (not the crappy cheaply scaled progressive scan DVD player HD-like output) then don’t assume that HDMI is better than any other connector.

In fact, it’s actually worse – in EVERY CASE of progressive scan DVD player I’ve tested.

Every single one.

Here’s the deal. HDMI is simply a connector standard – not a signal standard. What’s on the HDMI connector isn’t governed by any board or HDMI police or anyone else for that matter. OK, well, true high-quality HDMI digital content is somewhat governed (or controlled) by Intel and Silicon Image (the creators of HDMI) but what someone eventually puts on the HDMI connector isn’t.

Obviously.

Hopefully everyone reading this already knows this – we’re in the AV industry.

Progressive scan is the consumer code marketing term for what we know as scaling. What’s inside a progressive scan DVD player is, in almost every case, the cheapest possible scaler chip-set on the planet that will take NTSC or PAL video and scale it up to VGA, XGA, etc. (or in this case, 720p or 1080i resolutions). So, although the manufacturers are converting the video coming from a DVD (natively encoded at 480i) to 720p, 1080i and even just 480p, their “scaler” chip-set isn’t doing much to improve the signal at all – in fact, our tests showed that they were actually adding in noise that made the picture look worse!

Why would the performance be worse? Well, actually, that’s not the point of my column, however, I can tell you that in many cases its because the cost of DVD players is dropping virtually every month and it doesn’t make any sense to spend one on improving the quality of a standard that’s dying a rapid death due to the impending switch to Blu-ray discs as the high definition standard (no, not HD-DVD).

But, more importantly, you need to know the facts. Why connect DVD players in a system via HDMI just because it’s there? Go Component Video or, better yet, S-Video. I know you must think I am nuts, but think carefully about what I am saying and w3hat I have presented you here.

Obviously the native resolution of most projectors we are installing is at least 1280 x 720 in the HomeAV market and 1024 x 768 in the ProAV market. And, the video coming from a DVD player must be scaled somewhere – in one of the two pieces of gear (the DVD player or the projector/flat-panel).

So, where do you think the better scaler resides – the $100 DVD player or the $3000 display?