Visual QuickStart Guide [Electronic resources] : Final Cut Express HD for Mac OS X نسخه متنی

Rendering Strategies

To take full advantage of the media manipulation techniques that are possible with Final Cut Express, you will need to render to produce your finished results; you'll also need to render to review your sequence and evaluate any effects you've created. The rendering strategies in this section fall into three basic categories:

• Tips for avoiding unnecessary rendering

• Techniques for speeding up rendering times

• Schemes for preserving render files

Avoiding unnecessary rendering

Final Cut Express allows you to add source material whose frame rate and compression settings do not match your sequence settings. However, if the frame rate, frame size, or video or audio compression settings in your source media are different from the settings in your sequence, those frames need to be rendered before the sequence can be exported or printed to video.

If a particular group of source clips looks normal when you open it from the Browser window (Figure 18.17 ) but requires rendering or changes size or shape when you add it to a sequence and view it in the Canvas window (Figure 18.18 ), you probably have a settings mismatch between your source clips and your sequence settings.

Important: To avoid rendering when creating a sequence with cuts only, make sure that the sequence's editing timebase, frame size, and compression settings are the same as the frame rate, frame size, and compression settings of your source media.

How do you compare source clip and sequence settings? Open the clip's Item Properties window and note the clip's video rate, frame rate, frame size, and compression settings (Chapter 3, "Presets and Preferences."

Disabling rendering

There are two ways to delay rendering your sequence until you have completed your desired adjustments: you can enable the Play Base Layer Only option in the RT pop-up menu, or you can press the Caps Lock key to temporarily disable rendering.

The Play Base Layer Only option allows playback with minimal rendering. With Play Base Layer Only enabled, Final Cut Express will play the lowest opaque track in the sequence and all audio tracks rather than displaying the "Unrendered" message in areas that still require rendering. Cuts will be substituted for unrendered transitions. Motion will not be applied to clips or sequences when played back in the Viewer.

Reducing rendering time

Following are a few strategies that can help you minimize your rendering time. Using a lower-resolution draft quality saves disk space as well as time, because lower-resolution render files are smaller.

Using draft mode

Use a low-resolution render quality to perfect element positioning, motion paths, scaling, and other basic design decisions. After you are satisfied with the timing and movement of your effects sequence, start including your most calculation-intensive effects. Render short test sections first and then review them to evaluate your final image quality. If you are set up to use an external NTSC or PAL monitor, check your output on the monitor to see that your render quality is sufficient.

Rendering in stages

If you are building a highly complex effects sequence, you may want to render your elements in stages. For example, you might perfect just the motion paths and interactions of your composited layers and then render just that portion of your sequence in high quality by exporting and re-importing your rendered elements. The export process creates a new piece of source media, and you can continue to sculpt your sequence using the new composited clip as a fully rendered base track. Exporting to preserve a render file is described later in this chapter.

Batch rendering

Use the batch render feature to render all your projects while you're busy elsewhere.

Preserving render files

You may spend days creating a polished effects or title sequence in Final Cut Express and wait hours for your final product to render. How can you protect your time investment?

Following are a few strategies to help you hold onto your render files.

Salvaging renders with Undo

Final Cut Express allows multiple undos. If you just want to try a new idea on material you've already rendered, when you're done, you can undo (Command-Z) your experiment until you have reverted to your previously rendered file. Careful use of the Undo function can give you freedom to experiment without risking rendered sequence material.

FCE protocol dictates that when you invalidate a render file by changing a sequence, the invalid render file becomes unrecoverable either when you next save the project or when you are past the point where you can use Undo to make the render file valid again, whichever is later.

Exporting to preserve render files

Exporting creates a physical copy of your rendered file on your hard disk. Exporting is the safest way to preserve rendered material. Once you have exported render files, you can re-import and use them just as you would raw captured media. For your render file to be exported without re-rendering, the export settings must match the render file's settings.

Chapter 4, "Projects, Sequences, and Clips."

Tips

Before rendering a sequence that you intend to nest in a parent sequence, make sure that the nested sequence has the same render settings (frame rate, frame size, and compression settings) as the parent sequence to avoid having to render the nested sequence again. Final Cut Express cannot reliably track down all nested sub-sequence material that requires rendering when you perform a Render All process. If you have built multiple levels of nested, unrendered sub-sequences into your project, this tip's for you: Try rendering at least one element in each nested sequence to help FCE track down the nested rendering required. Double-check your rendered sequences before you invite your client in for a screening.