HDV's coming up.(high definition video)

If you're not that familiar with HDV, it would be both a little surprising and completely understandable. After all, over the past year HDV has become one of the video industry's hottest buzz-acronyms and most eagerly awaited product classes. But for the working creative professional, that's the rub: There hasn't been much in the way of products to actually use, at least until now.

HDV is nothing more than a format--a future format at that--and so it is perhaps not all that interesting to the active videographer or designer. But HDV is arguably the most intriguing format to come along since MPEG-2 (which also got a lot of press before there were really any usable products). Simply put, HDV is an industry-standard way to write high-definition MPEG-2 video, either 720p or 1080i, onto standard DV tape.

The promise of HDV and, thus, the anticipation is very much like that of early DV nearly a decade ago. DV brought professional-quality digital acquisition to handheld camcorders and immediately shook up the high-end versus low-end industry caste system. DV's quality rivaled that of the then-standard professional tape format, Betacam SP, and while there was debate about which was better, more professional, and appropriate for what purposes, DV was an eye-opener on price alone. In the decade since, regardless of that debate, DV has found a comfortable place among the tools of the trade. Now HDV is likely to travel a similar course for high-definition acquisition.

Compression Concerns

The basics of HDV are actually remarkably straightforward. Instead of the 25Mb/sec intraframe compression of standard-definition DV, HDV uses the temporal, interframe compression of MPEG-2 to squeeze higher resolution into the same 25Mb/sec (for 1080i, 19Mb/sec for 720p) bitstream of standard DV. There's greater compression at work, but mostly it's just more efficient use of the available storage capacity.

Makers of professional editing systems have long favored intraframe compression formats, such as Motion JPEG and DV for editing, and there are a couple of important reasons why. First, since most individual frames don't exist separately in interframe compression, and instead use data from neighboring frames, they often have to be rebuilt on the fly for an editor to be able cut on an exact frame, or to step or shuttle forward or backward through a specific clip or transition. Historically, re-creating frames that fast has been difficult to do. But with today's CPUs churning through data so quickly, it is becoming less of a concern.

Interestingly, it's the editing systems vendors--especially editing software companies that cater to a more price-sensitive audience-that are the most anxious for HDV camcorders to hit the market. While they focus on what is here today--most of them privately, and some not so privately--all see HDV as a big part of their future.