|There's a debate going on in the professional video world that's eerily reminiscent of one that occurred back in the mid '90s when the DV format made its first appearance.
Back then, the discussion focused on whether DV would one day replace the much-revered Betacam SP analog video format and the higher-end DigiBeta format. At the time, many dismissed DV as a toy for consumers, arguing its low quality was incapable of meeting the needs of true video professionals. But time proved the fallacy of such arguments, as the DV format slowly but surely infiltrated even the highest ends of the professional video world.
Today, a similar debate has emerged around HDV—a new high-definition video format that promises to make HD production affordable for nearly everyone. Since its introduction a year and a half ago, more and more vendors of video cameras and non-linear editing (NLE) software have announced their support for the format, and the list of HDV users continues to grow.
|Introduced last year, JVC's JY-HD10U is the only HDV camcorder on the market, although Sony plans to ship a competing product in the US later this year.
But the big questions about the ultimate role of HDV remain: Is HDV really bringing affordable HD production to consumers and video professionals alike? Does the emergence of HDV spell the end of the DV format? Will HDV equipment one day replace the need for the more expensive HD equipment currently on the market?
One of the most common myths about HDV is that it is the invention of one company, JVC. This misconception stems from the fact that JVC brought the first HDV camcorder to market back in April 2003, and even now, more than a year and a half later, its JY-HD10U remains the only HDV camcorder available.
Despite that, however, the HDV specification was actually developed jointly by JVC, Canon, Sony, and Sharp. And both Sony and Canon are expected to bring their own HDV camcorders to market sometime soon. In fact, Sony has announced it will begin shipping a new HDV model in Japan this month and will make it available globally by the end of the year.
According to Dave Walton, marketing communication manager at JVC, the HDV format was developed because of a need to create a more affordable way to produce HD content, a need made more urgent by the growing popularity of HD television sets. "The ability to view and display HD programming is growing at an incredible rate," he says. "However, until now, there has been a limited number of ways to shoot and record HD video, and those options have existed only at the high end of the price spectrum. And that's because HD video consumes a lot of data, so it has required high-capacity, data-driven systems."
To solve that problem, JVC and its vendor partners built the HDV specification around the same MPEG-2 compression scheme adopted by US broadcasters. While higher-end HD camcorders use an intra-frame compression scheme—which basically means each frame of video is compressed separately—the MPEG-2 format uses interframe compression (see "Comparing Compression Schemes," pg. 30). This eliminates some of the redundancy between frames, and allows the video to be recorded at a 19mb/sec data rate, low enough to allow the video to be recorded on DV cassettes, which can handle up to 25mb/sec.
The fact that the HDV format uses the same cassette case, tape speed, and track pitch as the DV format is a key factor in its affordability. It not only allows HDV to be highly compatible with the DV format, but it eliminates the need for vendors to redesign tape-recorder mechanisms. As a result, JVC was able to bring its HDV camcorder to market for just $3995.
|Cineform's Aspect HD is a plug-in program for Adobe Premiere Pro that lets Premiere users edit HDV in real time using a variety of resolutions and frame rates.
At the moment, HDV users are able to shoot HD video at 720p at 30 frames per second (fps), the only HD mode supported by JVC's single-chip JY-HD10U camcorder. (The camera can also record in standard definition at 480p at 60fps.) However, the HDV specification also supports 1080i HD video, and at the last NAB show, Sony and JVC demonstrated prototypes of three-chip HDV camcorders that will support that mode.
Excited by the ability of HDV cameras to provide nearly three times more resolution than DV cameras, Dave Taylor, CEO of Cineform, is bullish on HDV's future, even in the short term. That's not surprising, given that Cineform was one of the first vendors to provide NLE software for HDV.
The product is Aspect HD, a software-based plug-in for Adobe Premiere Pro that lets Premiere users edit HDV in real time in a variety of resolutions and frame rates, including 480p60, 576p50, 720p30, 720p60, and 1080i60. Unlike most other HDV NLE systems that have since come to market, Aspect HD is not a native HDV editor. That is, it does not edit the video in the MPEG-2 format in which the video is captured. Instead, it converts the video to Cineform's wavelet-based compressed format, which, Taylor contends, is better suited to the needs of the postproduction suite because video compressed with wavelet technology holds its quality through multiple generations.
From Taylor's perspective, the HDV format is already gaining acceptance among people in film, news, corporate events, and the like. "We anticipate that over the next three to five years HDV will totally replace DV," he says. "There may be some lingering work done with older equipment. But new equipment sales will shift dramatically toward HDV."
Walton of JVC is also optimistic about HDV's potential, but he isn't ready to concede that HDV is poised to replace DV. In fact, he says, asking whether HDV will obsolete DV is essentially like asking whether HD video will replace SD video. The answer, he suggests, is yes, although it's likely to be a gradual process.
"The decision as to whether someone will shoot in DV or HDV depends on the playback capabilities of their viewers," Walton says. "Moreover, there is a whole infrastructure that has developed around DV. That is not going away anytime soon. But one of the key features of HDV products is that they will be switchable with DV. So it's not a matter of one obsolescing the other. With the addition of the HDV capabilities, I think the life span of DV might even be extended."
But there are some video pros who are ready to make the transition now. One is Geoffrey Pepos, an independent filmmaker and founder of Rhythm Films. Last year, Pepos was in the middle of shooting his newest film, Purgatorie Playhouse, when, as luck would have it, one of the DV cameras he was using was destroyed during a shoot of some horse footage. When he went looking to replace it, he stumbled upon the newly announced JVC HDV camcorder and decided to give it a try. He ended up liking it so much, he shot the rest of the film with it.
|During the production of Purgatorie Playhouse, filmmaker Geoff Pepos switched from a DV camcorder to JVC's new HDV camcorder. While the HDV camcorder lacked some professional features, he was thrilled with the resolution and the progressive for
For Pepos, his experience with the JY-HD10U camcorder represented his first foray into HD, but he says he'll never go back to using DV. "This has got to be the future. Even if I'm doing SD work, I'll shoot it on HDV and down-rez it. It's just like oversampling in music. You get extra data that let's you create a higher-quality image."
Not everyone, however, is ready to leap onto the HDV band-wagon. Kevin C.W. Wong, director of photography at 4 Lanes Productions, has been working with the HDV format for nearly a year, employing it for a music video, a television commercial, and an independent feature film. He also has experience shooting with both DV and HD video, as well as film.
In evaluating HDV, Wong says the picture quality is good, especially for the price, and he believes the format has a great deal of potential. But he's also been frustrated by the lack of professional features on JVC's HDV camcorder—such as precise control over focus and aperture size—as well as the still-immature infrastructure that surrounds the HDV format.
Brian Greene of Greene HD Productions, a dedicated user of HD video who produces documentaries for HD broadcasts, believes HDV is suitable for consumers and producers of corporate and industrial videos currently shooting in DV. But for higher-end users, he feels the limitations of HDV are too significant.
One big limitation, Greene says, is the fact that JVC's HDV camcorder comes with only a low-end, fixed lens. So much of an image's quality depends on the quality of the lens you use, he says, and there's no way for a low-cost, small-format camcorder without either a broadcast or HD lens to provide the same quality as the more expensive HD cameras.
|Pepos began shooting with HDV after his DV camera was destroyed while shooting footage of horses. The quality of the images produced by his HDV camcorder were so impressive, he says, he won't go back to shooting in DV.
Beyond that, Greene says, because the compression ratio of the HDV format is so high, even if you had a quality lens, you would run into image quality problems.
"If you're shooting a static image, you'll get something fairly passable with an HDV camera," Greene notes. "But if you start shooting something with lots of color and fast motion in it, the image falls apart because the compression ratio can't keep up with the rate. You begin to see blocking. The image starts falling apart."
Still, Greene does see a role for an HDV camcorder in two scenarios in the high-end HD world. The first would be for situations when you need to get a shot in an extremely tight location where a larger HD camera wouldn't fit. The second would be for physically risky shoots where the camera could easily be damaged. In both instances, he says, an HDV camcorder offers a solution that's more attractive than doing the shot with a DV camera.
Neither JVC's Walton nor Cineform's Taylor disagrees with Greene's assessment of HDV's inability to replace high-end HD equipment. On the other hand, they are quick to point out that many of the limitations that currently plague today's first-generation of HDV equipment will be resolved with future product releases.
"We have to realize there are huge technology gains coming," says Taylor. "My argument is that second-generation cameras will have good lenses and other features demanded by the professionals in that marketplace. It is not a limitation of HDV. This was just simply a feature design spec that JVC used in its first-generation camera."
In addition to better lenses, the next cameras to hit the market will offer increased frame rates, 1080i resolution, and three CCD chips. Those kinds of improvements, argues Taylor, will represent an important step up for the HDV format.
Walton agrees. "Right now, the limiting factor is the camera itself," he says. "But as the camera technology improves, we are confident the format will accommodate the higher quality of the camera and thus deliver a much higher quality image."
|Pinnacle's Liquid HD Edition video editing system, which is scheduled to begin shipping this fall, will support native HDV editing.
While users will welcome those improvements, Pepos says that he's already able to overcome many current limitations through some creative work in postproduction. For example, he says, "HDV video does have a certain amount of chroma noise in it, especially if the contrast ratio isn't right. In lower light, it tends to get noisier. But if you look at the luminance of the camera, it's perfect. The resolution is there. So I've created a bunch of filter specs in Adobe After Effects—different ones for different types of scenes—and I've been able to smooth out the chroma. There are work-arounds for everything, and they are not really that troublesome."
That kind of creative spirit is something Walton thinks is essential for anyone willing to take up the HDV format in this early stage of its life. "There's no question that the SD products we and others sell are a lot more mature, and they have a lot of the subtleties that are appreciated by professionals. But if you want to do HD, you are going to have to put up with some inconveniences. That's simply the characteristic of a new technology. But people eager to be on the cutting edge are willing to do that."
In addition to the introduction of more HDV cameras with more professional features, there's one other development that many say must occur before HDV can really take off, namely the introduction of an affordable distribution medium for HD content. And the distribution medium that will most likely serve the need is HD DVD.
Unfortunately, the effort to create an HD DVD specification is still ongoing, a process complicated by the fact that there are two different groups of vendors supporting two different versions of an HD DVD standard. But the hope is that the first wave of HD DVD recorders may start hitting the marketplace by the end of the year.
Once HD DVD finally arrives, says Taylor, "I would expect there would be a fairly large adoption of HDV cameras. After all, why would anybody ever use anything but high definition once you can shoot and distribute it in HD?"
In the meantime, the HDV format is already receiving a big boost from the rapidly growing number of NLE software vendors and video board makers who are bringing their own HDV-compatible products to market. Among the vendors that have either recently announced new HDV-compatible products or have announced plans to offer them are Pinnacle, Ulead, Canopus, Matrox, Sony Pictures Digital Networks, Boxx Technologies, and Blackmagic Design.
Many of these announcements were made at NAB in April, and they represented a show of support for HDV that JVC's Walton, for one, feels was important. "This is an area that the editing companies really want to be involved in," he says, "because they know that the companies that get there first with the most elegant solutions are going to be in the driver's seat."
Alas, editing MPEG-2 interframe recordings is not as easy as editing intraframe video, Walton notes. So it is a challenge for the NLE systems to move over to a new standard. "But this is cool stuff," he says. "And I think it's going to be a hot area for the next few years."
Stephen Porter is a contributing editor of Computer Graphics World and a freelance writer who covers video, graphics, and digital content creation technologies and applications. He can be reached at firstname.lastname@example.org.
The main difference between HDV and mainstream HD formats is in the way they compress video. Unlike existing HD camcorders that use intraframe compression, the HDV specification is built around MPEG-2, an interframe compression scheme.
With intraframe compression, every frame of a video is compressed separately. In contrast, interframe compression strives to reduce the size of a video file by eliminating redundancies between frames.
In other words, if there is certain imagery that does not change from one frame to the next, an interframe compression scheme records that data only once and then re-creates it as necessary for each frame. The process is analogous to the way a copy-and-paste function works in a word processor, where the same information is used multiple times so it does not need to be re-created each time.
A big advantage of interframe compression is that it allows you to achieve a higher degree of compression, since less data is needed to create imagery for each frame.
On the downside is the fact that interframe compressed video can be harder to edit since cut points don't always fall neatly between frames as they would with intraframe compressed video. In addition, because interframe compressed video consists of less data, the video will not hold its quality as well when it goes through multiple generations, which often happens during the video editing and postproduction process.