HDTV Terms

If you've recent found our show because you're shopping for an HDTV or Home Theater component for Christmas, we're glad you've found us.  We also realize that there may be a bunch of terms and tech talk floating around that you don't fully understand.  Let's see if we can't clear up some of the confusion.  For those of you who've been listening to the show for a while, this will come as a review, so we'll go through each term very quickly.  That's the beauty of podcasting - if we move to quickly for some of you, you can simply rewind and play the explanation again.  We'll also provide links on the website for more detailed information about each topic.

1080p
First off, 1080p.  Sometimes referred to as "true high definition" or "full high definition," 1080p describes what you're watching.  The 1080 indicates how many vertical lines of resolution make up one image on the screen.  Just remember, the bigger the better on this one.  The 'p' stands for progressive, which is how the images are actually drawn on the TV.  Another format, 1080i, also has 1080 lines of resolution, but is drawn in an interlaced fashion, thus the 'i'.  High Definition TV is 1080p, 1080i, or 720p.  DVDs can be 480p or 480i.  Standard Definition TV is 480i.  You can see from the numbers that 1080i HD is a huge improvement over 480i SD.  Not to mention 1080p, which leads us to the i's and p's...

Interlaced and Progressive
In the days before digital displays, video signals were drawn on the screen in an interlaced manner.  Instead of drawing the full image, the TV would draw it in two passes, first drawing the odd lines, then immediately drawing the even lines.  It happens so fast that we can't even see it.  Then with digital display technology, we had the ability to display the whole picture at once, all the odd and even lines together.  This is called a progressive display.  For NTSC, the television displays 30 images (or frames) per second, which means it has to redraw 60 times per second because each drawing is only half of the picture.  With progressive video, we can get up to 60 complete pictures per second.  This is great for fast action, making the video much, much smoother.

More information

HDMI
Another hot topic is HDMI.  This seems to be the cable of choice nowadays for watching HDTV (unless your an Xbox 360, but that's a different story altogether).  HDMI stands for High Definition Multimedia Interface and is one cable that can carry both digital audio and video.  That in itself makes it very convenient.  In the early days of HDMI, the video part of the cable was equivalent to DVI, or Digital Video Interface.  With recent advancements in the HDMI spec, the two have diverged and HDMI is now the superior format.  Things to know about HDMI:

1. It is a digital cable, so a $15 HDMI cable will work just as well as a $250 HDMI cable
2. It supports HDCP or High Bandwidth Digital Copy Protection - so make sure any HDMI devices you purchase include support for this standard as well
3. It is required to get the best audio formats ('HD' Audio from Dolby and DTS) from both Blu-ray and HD DVD players

Display Types
Although they are on their way out, and many manufacturers are no longer making them, analog (CRT based) HDTV sets are still available.  They can usually be purchased for a very good price and although they tend to lack the detail and clarity of the newer digital displays, they have excellent color and impeccable black levels.  Most people will, however, be shopping for digital displays this year.  If you're going slim and sexy, you'll be looking at plasma or LCD.  As a rule of thumb, buy LCD for anything 40" or less, and buy plasma for bigger sizes.  If you want a bigger TV and want to save some money, the Rear Projection digitals are excellent.  The three types are DLP, made by most manufacturers, namely Samsung and Mitsubishi, LCD, also made by many companies including Sony and Hitachi, and LCoS, made primarily by Sony (as SXRD), JVC (as HD-ILA) and Olevia (as LCoS).

Surround Sound
As we've often said, HDTV without surround sound is only half the story.  To get surround sound you need a processor, often called a receiver, and a bunch of speakers.  The receiver will decode all the digital formats you can throw at it, except for the very new ones on the Blu-ray and HD DVD discs, but luckily those players will decode it for you.  After decoding the audio, your receiver will send the appropriate noise to each of the speakers you've placed around the room.  In a 5.1 setup, you have 3 speakers in the front of the room (Left, Center and Right) and 2 on either side.  A 6.1 setup introduces one speaker behind you, and a 7.1 setup introduces 2 speakers behind you.  The 'point 1' is your subwoofer - very important, don't forget the sub.  HDTV is 5.1, most DVDs are 5.1 and some are 6.1, Blu-ray and HD-DVD can go up to 7.1.

Remember, most of the sales people at the large electronics stores know little more than you do.  If you're ever confused, don't take their word for it, do some research.  Read up on it online, ask a friend, or email the HT Guys.  Merry Christmas and Happy Shopping.  Here's to a Holiday filled with HDTV, HDMI and 1080p - now that we all know what they are!