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Native HDV on Final Cut Pro 5

DV workflow for HD footage? By Charlie White

Until recently, high definition video production has been too expensive for mere mortals. Now, the HDV format has changed all that. But isnt there still a lot of data being bandied about? How will the footage be edited? Apples newest version 5 of Final Cut Pro has a solution to this problem, where the object of the game is to keep the HDV signal as untouched as possible as it winds its way through the computer and then back out to tape. Heres a close-up look at this native HDV editing process in Final Cut Pro 5.

The HDV format is appealing to video producers, mainly because of its low-cost high definition production workflow. The holy grail of this brave new world is the ability to shoot and edit high definition video using the same workflow weve all come to know and love when using DV camcorders and editing systems. Moving this dream closer to reality is the fact that even though a 1080i/60 HDV frame contains four times the pixels of its DV counterparts, its data takes up the same bandwidth as regular DV (otherwise known as DV25) and uses the same  MiniDV tapes.

HDV editing systems of the various purveyors take different approaches to the problem of editing this highly compressed HDV footage, crunched into a small space using an MPEG-2 technique called long-GOP (group of pictures) compression. Its difficult to edit because only certain frames, called I-frames, contain all the information necessary to create a picture. The frames between are just noting the differences between the last I-frame and the next one. So, its tricky to cut between I-frames, and its also challenging to keep this footage in its native format. Some developers, such as Sony with its Vegas editing software and Adobe, with Premiere Pro 1.5, both of whom use a variant of the CineForm HDV editing codec, have solved this problem by converting the footage as its captured into a different, editable format. The problem with this is the extra time needed to ?transcode, or render all that footage into an editable format. This format also results in much larger files, taking up a lot more disk space. So this is a problematic solution, because you must start rendering even before youve edited anything.

Enter native HDV editing, first introduced by Pinnacle and now available using a similar approach by Apple in Final Cut Pro 5. Apples technique lets you pass HDV footage into your computer untouched, and leaves it in its native state until you want to add an effect or a cut. For a cut, it only needs to add an extra I-frame around that cut, and rendering that small amount of data doesnt take nearly as long as it would if you had to render the entire clip. Even so, if youve added an effect such as color correction to a whole clip, the entire length of it must be rendered on its way out of the computer and back to tape.  

So just like in the early days of DV, you will need to render any effects on their way out of the computer, whether its to a file, DVD image or back to HDV tape. How you preview your edits in your computer is another story, however. Heres where the ability to natively edit HDV footage is an advantage. The good news is that with Final Cut Pro 5, multiple layers of HDV can be previewed in real time, and if youre just doing mostly cuts and a few dissolves with an occasional text key, you can preview it all in real time. But beyond a certain point if you want to preview these effects youll have to render them. If all youve done is cuts-only, the only rendering that takes place is when the footage is on its way out of your computer. Best of all, in this native HDV scheme of things, the only frames that need rendering are those that have been changed, say, where effects or cuts have occurred. Lets see how this works in Final Cut Pro 5.

Once youve installed Final Cut Pro 5, the first dialog box that appears is Choose Setup. Although it defaults to DV NTSC, its pulldown menu gives you the choice of a multitude of various resolutions. And there sits the one were going to use: HDV, 1080i/60. Among the others are DVCPro HD in 1080/50 or /60, along with DVCPro HD 720p/24, 30 and 60. Youre also given the choice of HDV 720p/30, the first-out-of-the-gate format that was so popular a couple of years ago with JVCs first foray into the lower-resolution version of the HDV spec.

After choosing that resolution and frame rate in the dialog box, it was a simple matter to plug in the FireWire cable from our Sony model HVR-10U HDV deck into the back of the Mac using an ordinary FireWire cable. The Sony deck was acting a bit balky at first, where the software and hardware wouldnt recognize the FireWire deck. After fiddling with the menus and telling the machine to output HDV instead of automatically selecting between HDV and DV, Final Cut Pro recognized the HDV signal coming into it via FireWire. We then realized as we played an HDV tape with the deck into Final Cut Pro, it would have automatically switched over to HDV anyway.

The next quandary was how are we going to monitor this magnificent high-definition video signal? Since the Sony deck gives you a variety of monitoring choices, we wanted to use S-Video out into a conventional monitor using a letter box format. Sure, its not high-definition video, but we figured it would give us a good idea of what were doing. But there was a problem with that. We were reminded of the old days of DV and Final Cut Pro when we discovered (and Apple confirmed) the inability of the software to loop through an HDV preview. Thats because HDVs long-GOP MPEG-2 doesnt encode as fast as it decodes for playback. The hardware is just not fast enough yet to encode the footage back into the HDV format on its way out. However, there are other ways to be able to see your HDV video in all its glory?you can use your primary or secondary computer monitor and use Apples Digital Cinema Desktop by hitting Command-F12. A second method is to use an inexpensive (about $600) DeckLink HD card that gives you a basic HD output on an external HDTV monitor. Of course, using a DeckLink card would also require you to purchase an HDTV monitor, so it might be more cost-effective to just get another Apple HD Cinema Display ($1500 for a 23-inch display  or $800 for a 20-inch model) to act as your HDV preview device. The weakness of this is that for color correction, you cant actually see what your final output will look like on a true HDTV monitor. But then, for editing, the Apple display works just fine. Of course, if youre doing color-critical work such as color correction, Apple recommends using a proper broadcast monitor with the associated output card.  

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Related Keywords:high definition video production, expensive, HDV format, Apple, Final Cut Pro 5, native HDV editing


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