HDTV on Your Macby Erica Sadun, author of Modding Mac OS X
So the other night, I popped over to Target to pick up an antenna. You remember what those are, don't you? Those telescoping metallic things that connect to television sets? That predate cable? Rabbit ears? I was about to buy my first antenna in, what, something like 20 years? I am such a cable-generation baby. I felt I was walking into a time warp (and not the good Rocky Horror kind, either) until I walked into the actual aisle.
It was the packaging that hit me first. Target had about a dozen or so antennas on sale, and every single one (and let me repeat that, just to be emphatic, Every Single One) had an HDTV digital-ready sticker on it. I hadn't walked back into the past--I had just entered the present. This was the world of "Terrestrial HDTV": high-definition television broadcast over the airways. The GE "Futura™" unit I picked up (got to laugh at the name, but it was only ten bucks) proclaimed that it was "designed to receive the highest quality broadcast HDTV signal." You've just got to love that.
As a platform, Macintosh is a little late to the HDTV party. PC solutions (both Windows and Linux) are more abundant and better supported, but who wants to use a PC unless you have to? Sticking with Mac, you can either fork over the medium-to-big bucks to buy a turn-key solution, like ElGato's EyeTV 500 ($350 USD), or you can try to put together your own system using a decoder card, an antenna, some freeware software and a lot of love, elbow grease, and spit. Naturally, I chose the latter.
Author's note: This article discusses American NTSC broadcast of high-definition television. Apologies to readers from other countries.
When you watch TV on a traditional television set, you're watching fairly low-quality video. The analog signal contains 525 vertical scan lines with a horizontal resolution of, say, 400 to 500 dots. And of that whole picture, you can see maybe two-thirds of it because your good old picture-tube-based television set does something called "overscanning" to protect the picture tubes against the effects of aging. Enter something called ATSC. ATSC stands for Advanced Television Systems Committee, an American standards body that defined a way to transmit pure digital signals using MPEG-2 compression to your television set. (Yes, that's the same MPEG-2 compression used by DVDs.)
When you watch TV on a traditional analog set, the television (or a converter box) grabs this digital signal, converts it to analog format, and displays it. It may look better than the quality you're used to, but it's nowhere near as good as the quality you'd see on a purely digital set. Analog TVs can't even begin to do justice to HDTV's 720 or even 1080 broadcast lines of resolution, let alone the horizontal resolution of 1280 or 1920 dots per line. You could spend a lot of money buying a digital HDTV set, or you could arrange to watch things on your computer for a lot less money.
Types of Digital Video Broadcasts
In the United States, you can receive any of three kinds of digital video broadcasts. These include:
Terrestrial digital video, which is broadcast over the airways using the ATSC standard. Your local network affiliates and public television stations send out the signal from their local towers. This makes the signals directional, so some antenna adjustment may be needed to properly receive the broadcast.
Satellite digital video, which is broadcast via satellite television using a variety of standards, many of which are proprietary. Some satellite companies (like DirecTV and Dish) also provide terrestrial ATSC tuners to their customers to receive local network broadcasts.
Cable digital video is broadcast over cable systems that provide Digital TV service. HDTV channels are added as they are established, usually in the upper reaches of the numbering system. As with satellite broadcasts, cable providers use a number of standards including OpenCable and DVB-C.
From a Mac point of view, reception options are limited. ElGato's EyeTV 500 can receive, display, and record both terrestrial and (some) cable signals. Existing solutions for the U.S. do-it-yourselfer are currently limited to receiving terrestrial ATSC signals and unencoded OpenCable transmissions. (Unfortunately, few cable companies transmit unencrypted HDTV.)
Finding a Broadcast
If you want to find digital broadcasts in your area, point your browser to Antenna Web. You'll need to enter your zip code to perform the search.
To start, enter your zip code and click Submit. A new page opens, displaying all the over-the-air broadcasts in your vicinity. Click the Show Digital Stations Only radio button. This limits the display to digital broadcasts.
For the example shown here, it'd be best to aim your antenna due West. At 270 degrees, you'd have the best chance of receiving broadcasts.
Step 1: Getting Started
In order to start watching HDTV on your Macintosh, you need to have a certain number of items on hand. These include the following:
A higher-end Mac. You'll need a dual 1GHz Mac or a single 1.44GHz Mac at a minimum. Even faster is even better. HDTV takes up a lot of processing speed. Also make sure you have lots and lots of free disk space, so you can record your programs as you watch them. You'll need to use a tower-type system with at least one open PCI slot.
Tip: Want to save a couple of bucks at Copperbox? If you have a spare opossum picture (even road kill), email it to to claim your discount. My brother-in-law once gave me a set of 'possum coasters, complete with tire tracks. Finally, they (and my handy-dandy flatbed scanner) came in useful for something!
An antenna. Target. 10 bucks, give or take.
It's easy to get set up. Just crack open your Mac case and install the PCI card. Close the case back up, connect your antenna to the card and you're set. You'll need to install a driver and the proper viewing software, as you'll see in the next section.
Step 2: Download the Software
You can find most of the software you'll need at John Dalgliesh's defyne.org website. John is the author of iTele, tunetest, and more. (He is also a kind and patient man, who helpfully answered many technical questions for me.) Here's a list of the software you'll want to have on hand.
The MMInputFamily Device Drivers. In order to view HDTV, you'll need to install these device drivers so your software can communicate properly with your capture card.
iTele, a viewing application that lets you watch your HDTV programs. iTele can automatically scan the airwaves for active signals, display them for you to watch, and record them to disk. It's currently at version 0.5.7.
Mplayer. Mplayer is a port of the Linux movie-viewing application. iTele supports two ways of watching video. You can use an internal viewer (that is to say, within the iTele program itself) or Mplayer as an external viewer. Download your copy of the OS X MPlayer from Source Forge. The current version is 2b8r4.
Step 3: Install the Drivers
Follow these steps to download and install the MultiMedia Input drivers for your new HDTV video card.
Double-click the .dmg file to mount its disk image on your desktop.
Open the newly mounted disk image. Inside you'll find the installer software.
Run the installer.
Read the instructions carefully. As John says on his site: "[D]o not just click through them!"
You don't have to reboot your computer to continue, but it won't hurt.
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