Without additional hardware, Final Cut Pro attempts to play back composites and transitional effects without rendering them first, depending on your hardware configuration. Again, the faster your setup, the more-reliable and more-complex real-time effects you can achieve. Depending on your computer's speed, you might have to render effects eventually to print them back to DV tape in any case if they are DV. Real-time (RT) effects are being done with capture card additions such as those from Aurora, Matrox, AJA, and Pinnacle. They might add real-time effects that you cannot achieve with RT Extreme alone.
If you click the RT button in the upper-left corner of the Timeline window, you can set your playback of real time to Unlimited RT. Using this to preview effects you've added to your sequence allows you to see them in real time as long as they are real-time effects with their names in bold.
They might not play back smoothly, but they allow you to see changes before you waste time rendering them if further changes are required. For more information, see Figure 3.21 in Chapter 3, "Understanding Final Cut Pro's Interface: An Overview," and the render bar discussion in the section "Composites and Renders " earlier in this chapter.
There are some additional caveats here. Not all effects play back in real time. Only the bold effects in the list of filters and transitions will work in a preview without rendering. Not all Macintoshes can play back real-time effects. The faster your computer's processor is, the more real-time playback you can achieve. Dual-processor machines show more RT previews than single processors. Only 500MHz G4s or faster show you any RT effects, according to Apple, but slower machines might show you some . What's more, if you are working in one of the OfflineRT modes, you can get more effects to preview. Confused? Join the club. Here's the last caveat: Typically only on the faster dual G4 computers can you get more than one RT preview effect at a time.
The bottom line is that if you can get some of the effects to preview for you in RT, great! It's not the end of the world if you can't. There are some nifty tricks you can do to look at the effect as it plays even if you're working on a G3, if you want to preview the effect and continue monitoring your video externally, or if you're working with effects that have no real-time preview.
Nifty Tricks When Real-Time Playback Isn't Enough
The first of these tricks is the Opt+P keyboard command. It renders any effect or set of effects and shows you the frames in the Canvas as it builds them. The faster your computer, the faster it shows you this preview. It's really great when you want to check a middle section of a composite or effect and you don't want to wait for a rendering to get there. Rendering starts with the first frame of the selected clip and goes frame by frame until it gets to the area of interest. Opt+P, on the other hand, shows you a slow playback from anywhere you place the position indicator in the Canvas or Timeline windows . If this area can be played in real time, it will be.
The second trick is to drag the position indicator through the effects or jump through them every few frames by clicking in forward steps in the Timeline window. You'll be able to see if you have indeed set up that flying move of 10 layers of picture-in-picture clips properly or if that background of a video transitional page turns just right.
Another tool to help you preview unrendered material is the QuickView window. It's discussed next .
The QuickView Window for Previewing Effects
The QuickView window gives you another way to preview your effects before you render them. As you play a specified area of your sequence, video is cached to RAM as it's played. If you are familiar with After Effects, it is a RAM previewing tool. As soon as the duration of the sequence you've specified for QuickView playback has played all the way through, subsequent loops of it play at the full frame rate because they're being played back directly from RAM.
The QuickView tool stores in RAM as much of the sequence between the In and Out points set in the Timeline as possible (determined by how much RAM you have installed) for accelerated playback. If only an In point is set in the Timeline, Final Cut Pro caches video from the In point for the duration you specify in the Range slider for playback in the QuickView window. If no points are set in the Timeline, Final Cut Pro uses the playhead's position, caching half of the duration specified by the Range slider before the playhead's position and half after the playhead for display in the QuickView window. When you choose an In and Out point in your sequence, the Range slider is defeated.
To activate QuickView, choose Tools, QuickView or press Opt+8. It opens in the Tool Bench and resides there with the Video Scopes. You can click the tabs there to switch between them or drag either tab to keep them both open .
Figure 11.36 shows this window's controls. The pop-up menu in the upper left allows you to cache the video in full, half, or quarter resolution. Using the lower-resolution modes not only lets you play back sooner than a render to disk and render the preview faster, it also lets you load more time into RAM. The View pop-up menu in the upper right allows you to select which window to view with or to automatically switch to the Viewer or Canvas window for a QuickView playback.
Figure 11.36. The QuickView window.
To activate the play button under the picture area, click it or press the spacebar to toggle it on and off. The Range slider slides from left to right, selecting more or fewer seconds to work with in the looping playback. You can click the position indicator just above the play button to scrub through the loop.
You can also select a specific range you want to preview in your sequence by setting an In and Out point within the sequence. When you do, the QuickView window assumes that this is the range you want to preview.
If you lower the playback's resolution, this tool becomes more powerful. Even though the picture becomes somewhat fuzzy, if you are animating titles or watching many layers of video play through, you can at least check positions of your clips to see if you have indeed programmed them correctly. It's much better than discovering that after you've waited for a long render, you have to rerender because you made a mistake. Unlike working with RT settings in the Timeline window, QuickView works with every effect you can add to a clip in Final Cut Pro, whether it's a bold RT effect or not.
Composite modes are discussed in detail in Chapter 13. They provide extremely powerful and useful effects. You'll discover some of their uses while editing the movie. They calculate differences between pixel values when you place images above each other. Using these modes gives you all sorts of interesting effects.