Blu-ray Support

Blu-ray support

YouTube, MobileMe, and Apple TV are nice, but the feature that many HD producers have been clamoring for is Blu-ray support, which Apple also added to the suite. Here, Apple focused on the fast and easy production of simple projects such as the encoding of dailies and other videos for client approval, or simple tradeshow or business demos. Full-featured authoring was not the focus. Operationally, you insert chapter markers on the timeline as before, and then choose Blu-ray from the Share menu.

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Figure 6. Blu-ray menu creation (and preview) in Final Cut Pro.

Apple includes five HD menus. You can build your own in Motion, or customize in the Share menu by inserting a custom background image, logo, or title graphic. Final Cut Pro creates all required chapter menus and all links between all menus and chapter points. Navigation is all preset—menu to menu, and then to chapter points—so there’s no menu branching. You can use markers for closed captions, but there’s no provision for multiple audio tracks, pop-up Blu-ray menus, or the like, and no way to preview your title before burning to disc.

In addition to Blu-ray titles, you can also produce an AVCHD disc using the Share menu, which burns HD output with menus onto a DVD-R/+R disc using a standard DVD-R/+R (e.g. legacy drive). This is a nice option when you have limited footage (40 minutes maximum), though compatibility may be an issue. AVCHD discs don’t play on all Blu-ray players. Note that Apple’s own DVD player doesn’t play either AVCHD or Blu-ray Discs, which is unfortunate for producers who don’t have a compatible set-top player close at hand.

New ProRes formats

I’ve always liked Final Cut Pro for AVCHD production because working with material converted to ProRes is so much more efficient than editing AVCHD natively. Inside, however, I always cringe at the 147Mbps data rate that balloons the AVCHD file by a factor of about five.

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Figure 7. The Apple ProRes family: ProRes 4444, ProRes 422 (LT) and ProRes 422 (proxy) are the new members.

Apple addressed this concern with three new flavors of ProRes. At the high end is ProRes 4444, with the last 4 representing alpha channel. Aimed at high-end post and visual-effects houses, the bit rate at 1080i is a maximum of 330Mbps (without an alpha channel), compared to about 220Mbps for its older sibling ProRes 422 (HQ). At the low end are two new levels, ProRes 422 (LT) at 102Mbps and ProRes 422 (proxy) at 45Mbps, which should prove useful to AVCHD and HDV producers such as myself.

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Figure 8. A comparison of the three lowest-quality flavors of ProRes. Click here to see the image in detail.

As an aside, I asked the Apple product manager what we can know about the mathematical basis for ProRes—is it wavelets, fractals, JPEG, or other technology? He responded that Apple has never disclosed the underlying math because whatever the technology, it would predispose potential users one way or the other. Now you know why you don’t know.

At the demo, the rep showed me side-by-side comparisons of the ProRes versions all the way down to proxy, and they all looked very similar. Back in the lab, I converted my standard HD test clip to the three lowest-quality ProRes flavors and compared the results, which you can see in Figure 8, a screenshot of the three clips magnified 2X. On the right, the ProRes 422 (proxy) clip showed minor distortion and some blockiness in the two ballerinas’ faces, while the ProRes 422 (LT) clip was very, very close to the ProRes 422 clip.

Overall, the ProRes 422 (proxy) format is ideal for its namesake task. ProRes 422 (LT) seems like a useful alternative to ProRes 422, offering nearly equivalent quality at a data-rate savings of about 30 percent.


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