First there was high definition television. Now, we have HD radio, HD audio, HD furniture for your home theater, and even an HD church! It should be no surprise, then, that the first class-action lawsuit has been filed - over HDTV.

According to TVWeek.com, Plaintiff Philip Cohen, himself an attorney from California, claims in a class action filing that DirecTV doesn’t really transmit full high definition TV through its direct-broadcast satellite (DBS) service.

Rather, Cohen maintains that DirecTV has compressed its HD programs so much that picture quality has been severely downgraded. As a result, he is paying a premium for a service he’s not getting, which constitutes a fraud. The original suit was filed back in 2004, but DirecTV’s motion to go to arbitration was denied recently by a Los Angeles court, presumably allowing the suit to go forward.

It’s not exactly a big secret that broadcasters, DBS operators, and cable TV companies all employ varying degrees of digital compression to conserve expensive bandwidth and maximize channel availability. The sticky wicket is just how much compression to use.

For the past several years, I have presented a seminar on digital TV that includes a discussion of MPEG compression and its effect on the picture quality of 720p and 1080i HDTV broadcasts. The equation I ask my audience to consider involves the three B’s: (1) Bit rate vs. (2) Bandwidth vs. (3) Bucks.

Since #2 is usually fixed and expensive, many content providers choose to maximize #3 at the expense of #1. Think of a see-saw with bandwidth at the center of the board, and bit rate and bucks sitting at either end - as one end goes up, the other must come down.

Compression might not be a problem if the viewer at home is using a small HDTV screen, such as a 32-inch CRT set. But compression artifacts will clearly be seen on larger screens with higher resolution, and as market trends have shown, 37-inch and larger 720p and 1080p sets are selling in ever-increasing numbers.

Cohen’s suit alleges that DirecTV allowed the bit rate of its HD channels to drop down as far as 6.6 megabits per second (Mb/s), far below the maximum allowable ATSC bit rate of 19.39 Mb/s. This action in turn severely decreased picture resolution.

There are no statutes regulating the quality of HDTV, unlike the weights and measures stamps seen on gas pumps or the sanitary certifications of restaurants. Nor should there be. The decision to compress (and multicast other channels as a result) should be left up to the content provider.

However, it is the responsibility of HDTV content providers to audit their own picture quality. The CBS network broadcasts all of its 1080i HDTV programming at 18 Mb/s from its owned-and-operated TV stations, and the network engineering department monitors picture quality on a variety of HDTV sets as large as 60 inches.

In contrast, some MPEG stream analyses I conducted a week ago in upstate New York and Pennsylvania showed smaller-market DTV stations compressing their 1080i and 720p HD signals as low as 8 - 9 Mb/s in order to carry more secondary channels. The resulting deterioration in image quality is noticeable, particularly when broadcasting live sports like football - ironically, the very thing that drives sales of big-screen HDTV sets.

Even major market stations aren’t immune to the problem. Last night, I watched the Monday Night Football game in 720p HD, originated by ESPN and carried by my local off-air ABC affiliate, WPVI-DT. It was clearly evident that WPVI’s MPEG encoder was not set up correctly, as the HD football images shifted from very crisp and detailed to soft and fuzzy each time the MNF logo spun across the screen.

Was the broadcast HDTV? Certainly ESPN’s feed of the game was clean going to WPVI, as well as cable head-ends, DirecTV, and Dish. But the difference between 720p picture quality in the ESPN HD transmission and WPVI’s HDTV re-transmission was astounding, to say the least. I’ve seen better images from DVDs!

Plaintiff Cohen may be on to something, although legal experts say he’s in for a tough battle to even make it to court in California. Still, the odds are that we’ll see more of these filings as consumers upgrade to bigger HDTV sets, shell out plenty of dollars for "premium" HDTV services to their cable and DBS providers, then realize they’ve just paid filet mignon prices for hamburger…