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Shooting HVX200 for DVD

May 9, 2006 5:29 PM, Barry Braverman

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Many folks have trouble grasping a simple fact that the DVD player is a native 24p device. This means that optimal SD DVD workflow from image acquisition to encoding to DVD-compliant MPEG-2 should ideally be performed at 24p. It need not and should not entail interlacing à la NTSC (or PAL) until the last possible moment, and that being the final output from the DVD player to the display.

That DVD players should operate natively at 24 FPS ought not be surprising. After all, Hollywood product is typically photographed on film and finished at 24 FPS so encoding to DVD at other frame rates would be both inefficient and counter-intuitive.

Encoding 24p (film) programming at 29.97 NTSC invites not only ugly artifacts but also negatively impacts a project’s bit budget; the higher frame rate requiring 25-percent more disc space with no associated benefit. Thus shooting, editing, and encoding 24p makes ultimate sense if your primary release vehicle is standard definition DVD.

The advent of the Panasonic HVX200 P2 camera introduces a new wrinkle in today’s preferred 24p workflow. This is because the HVX camera shoots in at least 81 different formats and modes, including multiple frame rates and resolutions; indeed the camera can record 24p in at least ten different ways! So the question becomes which 24p option makes the most sense for ultimate output to SD DVD.

In my recent book VIDEO SHOOTER (CMP Books/2006), I explained the logic behind shooting HD for SD release. The additional fineness that HD cameras offer at the 480-line standard definition cutoff is readily apparent; the marked increase in contrast lending itself to stellar-looking images when shooting DVCPRO HD or even HDV for ultimate encoding and distribution in MPEG-2 standard definition DVD.

The HVX200 expands this 24p mandate significantly, offering shooters the ability to shoot 100 Mbps DVCPRO HD at 1080p24. This option combines the advantages of a 24p workflow with the HVX imager’s 1080p capability, the camera sampling initially at 60 FPS before downconverting as required from there. The “1080i” options in the HVX at 24 FPS and 30 FPS are in actuality progressive scans, the clock speed of the camera processor being slowed in the off-imager processing to enable the reduced frame rates.

HVX200 shooters for DVD should be aware of the erroneously placed “i” in the setting descriptions in the camera’s RECORDING FORMAT menu. The resolution/frame rate of particular interest to SD DVD shooters, is indicated as “1080i24p” despite the fact that images are scanned natively in progressive mode and not therefore derived from or the result of field blending of the interlaced frame.

The 1080-resolution settings described as 1080i24p and 1080i30p would be more properly identified as “1080p24” and “1080p30”. There is simply nothing interlaced about either of these two settings, the camera’s clock speed being reduced proportionately during capture, and the resulting 24p or 30p images retaining the original 1080-line progressive scanning albeit at a reduced frame rate.

The recommended shooting-for-DVD frame rate of 1080p24 outputs a transmittable video stream over FireWire and thus can be recorded to an external recording medium such as a laptop’s hard drive* or Firestore FS-100 HDD recorder. No P2 card need be installed to shoot at the 1080p24 frame rate so extended run times up to 90 minutes to the Firestore (or more to a larger generic drive) are possible.

At 720p, HVX shooters face additional choices since the camera can shoot 720p24 over 60 FPS like a Varicam, or at 720p24pn. In the latter native mode, the HVX200 does not output video over FireWire; the individual data frames (not transmittable as video) being only recordable to the camera’s internal P2 card. Shooting 24p with the HVX200 in either Varicam or native mode produces an identical quality frame, the advantage of shooting 24p at a native frame rate being the 2.5X greater capacity enabled in the P2 media.

Whatever workflow the small-format HD shooter adopts, whether recording to a laptop, Firestore or P2 card, shooting 24p for standard definition DVD makes eminent sense. With the advent of the HVX200 and its true 1080p24 capability (albeit improperly identified as 1080i24p), shooters have the option to produce stunning HD images optimized for output to standard definition DVD.

For several years, we shooters and producers of DVDs exploited cameras like the Panasonic DVX100 to take advantage of an all-24p workflow. The HVX200 leverages the 24p workflow advantage, adding now 1080p image acquisition to a winning formula.

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