Joel Silver's Tips When Using HDMI
1. Don't Rely on Factory Presets
We have a saying around here: give me the picture, the whole picture, and nothing but the picture. And you cannot depend on factory presets to get you the whole picture, especially when you're mixing different brands of components. So the first thing I look for are picture quality adjustments, not just on the TV but on my sources. I won't mention the brand but we recently bought four advanced DVD players, same model, same reseller, same city, and each required very different adjustments for brightness and contrast. In consumer-priced goods, this is the norm. To address this you need some kind of basic test-pattern disc – a cheap but indispensable tool if you want to deliver the whole picture to your client. For example, if black is set to PC black, you'll have a bad picture if you're watching television because the CE world defines black differently. Many devices have a switch for this: 0 vs. 7.5; "Enhanced black;" "Higher/Lower;" or "Darker/Brighter." If your test pattern shows under-black, you know you're not getting the right picture. If you want the whole picture, don't guess; test for it – and test both ends of the cable. It could be either device – don't blame the cable!
2. Optimize Aspect Ratio
If the source is high-def, we can assume wide screen. Thankfully, with HD-DVD and Blu-ray players, that's going to be the preset – one of the simpler things in our new world. But our old movies come in multiple formats: widescreen, old-fashioned letterbox, and old-fashioned TV, which is going to exist for many years whether we want it or not. So the installer has to make sure that's set correctly, and understand which TV setting is proper. The critical part of this is that we're now in a 1080p world. 1080p sources are common, and so are 1080p displays. But virtually all consumer TVs have an overscan feature, which magnifies the picture a bit to hide the ugly edges, so you're not really getting the full 1920x1080 picture. With an NTSC source, or with many satellite and cable systems, you may just be stuck with it – but you should never tolerate overscan when the source is HD-DVD or Blu-ray. There is no good scaling, period. So one of the new – and critical – aspect ratios is the one with no overscan, whatever the manufacturer calls it. New devices coming out soon will feature a "JUST" (Justify) setting, but it's also known as point-to-point or pixel-to-pixel, and it means a full 1080p image with no scaling. If you've pressed a button labeled "keystone," "horizontal," or "vertical," go back and unpress it. You can destroy the picture.
3. Invest in Test Tools
Should you own test tools? In a word, yes. They can get expensive, but any business requires a certain level of investment. Something fairly simple called a multiburst – a collection of vertical lines that get finer – is a good place to start. It documents to your eye whether the pixel mapping and aspect ratios are set correctly. You can get them on discs, you can get them in portable, battery powered generators – but you've got to have this. As we say around here, "We get paid to know what we're doing." We don't guess, we test.
4. Understand PC HDMI vs. CE HDMI
We're already seeing a lot of PCs in home theaters – especially with the younger clients – and we expect this trend to ramp up for two reasons. First, big-screen gaming is here to stay. Second, PCs will be recording HD from multiple sources by the end of '08 – let's call them servers, and whether they're CE-based or PC-based has nothing to do with it, they'll be HDMI-based. You'll have to deal with the PC sooner or later, and it's not without its challenges. The technology is very new, and often it's an adaptation of DVI, so don't expect the PC to work with every other HDMI device. But the Vista OS has a number of utilities to help you. First, make the most aggressive possible selection on talking to outside monitors. Second, look for something in the advanced menus called "EIA Timing," because 1080p/60 is not really 60 in the CE world, it's more like 59.94, a fraction, not a round number. Some TVs just won't mate with true 1080p/60 – they want a CE source, not a PC source.
5. Field Test for HDCP Issues
The handshake has to be compliant in both components or we have a failure to communicate – so look in both directions if you have a problem. Moreover, it has to be compliant whether the device is currently active as an input or not. Sometimes we encounter trouble switching back and forth between inputs. If this happens you may be forced to down-res to component video until you can upgrade the device's software (or upgrade the device itself). If you have four sources, switch repetitively between all four, in every order you can think of, multiple times before you walk away from the job site. They need to be compliant whether you're watching them or not, in the on state going to off state and vice-versa. Never guess; always test. Change inputs, spend some time powering devices up and down; do this while you're at the job site or you'll be going back to the job site. And whether it's Blu-ray or HD-DVD, it's absolutely critical to make sure you have the latest firmware updates for the device. Keep in mind that the software behind HDCP is a moving target, and can be updated at any point to stay ahead of piracy. Make sure these devices are online, or plan on coming back on a regular basis to update them. If you schedule yearly visits to recalibrate, as many installers do, you can update all the firmware while you're there. Clients should be educated on this issue, so they understand that they may need new firmware, and that this may require a service call.
6. Choose the Right Cable
Are all HDMI connectors the same? No – and I learned this the hard way myself. I used to encounter 1080p failures on a regular basis because I didn't know Cat 1 from Cat 2. If you're running 1080p, or longer than 10 feet, why risk it? Use Cat 2 cables. And don't treat them like analog cables: don't stretch, don't tug; they're not for chin-ups. Remember that you can't field-terminate if you break one. Personally, if it's more than a meter, I don't go for cheap cable. And if it's in a rack that's going to move, I buy for durability. A little extra armoring – making sure the actual metal of the wire is connected to the metal of the connector with some stress relief – is never a bad idea. It's the way we work – we're not surgeons. Sometimes we don't have time to do things perfectly, we ram things in and we pull them around. Hedge your bets. Cables are cheap, components are expensive.
The views and opinions expressed herein are those of the author and do
not necessarily represent the views and opinions of HDMI Licensing, LLC,
the HDMI Founders or any of their respective parent organizations or
affiliates.