Apple Pro Training Series: Optimizing Your Final Cut Pro System: A Technical Guide to RealWorld PostProduction [Electronic resources] نسخه متنی

Priming Final Cut Pro

Unlike some turnkey solutions, Final Cut Pro provides a flexible software environment and is able to support a wide variety of hardware solutions and accommodate a diverse range of tasks. In order to create the optimum conditions for your specific workflow, you need to set up FCP to take the best advantage of your system's resources. In this section of the lesson, you'll learn how to set scratch disks, manage the way memory is allocated, adjust real-time performance, and configure audio outputs.

Assigning Scratch Disks

Scratch disk is a generic term used to identify space on a hard drive for temporary, rather than permanent, data storage. When you're working with Final Cut Pro, media files, caches, and the

Autosave Vault are all considered transientyou work with them on individual projects and then clear space ready for the next. You can create a scratch disk on a separate physical drive, a partition, or a combination of both. Usually, when you're setting up a high-end system, you should use different locations to optimize performance. All you need to do is tell FCP exactly where to put your files.

Setting the Primary Scratch Disk

You can't actually run Final Cut Pro without a designated scratch diskyou're prompted to choose the default location when you launch the application for the very first time. Once you set your scratch disks, that information is stored in your FCP preference files. Whenever you trash the preference files everything will be reset to the initial settings the next time you launch FCP.

Tip

To prevent problems during capture, use distinctive names for your drivesuse dissimilar combinations such as Alpha and Beta, Artoo and Threepio, or Murch and Schoonmaker rather than Media and Media 1. Unless you're working with Xsan and shared storage, you should be able to change the names of your partitions or disks without reformatting. You can also assign names in Disk Utility when you initially set up your drives. Refer to Apple's Web site for further details: http://docs.info.apple.com/articl182?artnum=36726.

Resetting Scratch Disks

Unless you're working on a system with a single local hard drive, you'll need to change the default location of your scratch disks to specific media directories. Occasionally, you might also encounter a Missing Disk alert, which means at least one of your scratch disks is offline and needs to be reconnected or reset. The process of setting scratch disks in both cases is identical.

Note

Select an area on your media drives, or designate an area on your startup disk if no other drives are available. If you are working with a SAN solution, do not create the scratch disk at the root level of your network drive. Refer to the Xsan lesson in this book for further details

This exercise involves deleting your Scratch Disk folder, after which you will not be able to retrieve its contents.

Assigning Separate Media Scratch Disks

Unless you're working with low-resolution media, or editing on a PowerBook G4, when you're creating and optimizing a high-end system the optimal place to store media is on a fast, dedicated hard drive. (Refer to Lesson 9 and Lesson 15 to review the different options for storage and Xsan implementation, respectively.) You can set up to 12 separate scratch disks for your media files at once, and separate video from audio and captured files from rendered files. FCP always uses the disk with the most space first and moves onto the next one only when the original is full.

Managing Waveforms and Thumbnails

By using cache folders, FCP doesn't need to redraw waveforms and create

thumbnails . Without the Waveform Cache, FCP would constantly need to analyze audio files and create a new picture of the sound. Similarly, without the Thumbnail Cache, FCP would access video files and create preview images all the time. Storing and reusing the images files in this way is much more efficient because FCP is relieved from the task of re-creating a waveform or thumbnail whenever they are required.

As with media files, your Waveform and Thumbnail Caches need a home. Storing the data on a fast media drive may mean that your system can access them quicker, but it also means that your dedicated drive is no longer focused on its primary task, which may slow performance. In a later lesson on Xsan integration, you will learn that you

should not store your cache folders on Xsan volumes. Storing the cache files on a local drive, including your startup disk, will not trouble most systems, but because the cache files are not project specific, nor is there need to back up the data, you

should not store them in your projects directory.

In the event that either your Waveform or Thumbnail Cache becomes corrupt, simply delete the individual directories in the Finder. The next time you launch Final Cut Pro, the cache folders will be re-created.

Note

Because FCP uses the Waveform and Thumbnail Caches to keep track of data, their sudden absence can cause unpredictable behavior. You should always quit the application before you delete them.

The way data is stored in the two cache folders is quite different. There are only two files in the Thumbnail Cache: a Cache file and Data file, which contain the current information about

all open projects and sequences. In the Waveform Cache, each clip acquires a unique file, and the cache folder may contain many hundreds of files, including some from projects that are no longer current.

One way to improve all-around performance is to reduce the number of thumbnails and waveforms you're working with.

Create the Autosave Vault Folder

The Autosave feature of Final Cut Pro provides a level of protection for your project files. By default, once you've saved and named a project, FCP will automatically save a copy of the project at predefined intervals. What this means is that should something untoward happen to your project file, and it is rendered unusable, you have the option of

reverting to a version in the Autosave Vault.

Each file in the Autosave Vault is an exact copy of your project, with a change to the filename, which is appended with a timestamp to indicate the moment the backup was created. By naming files sequentially in this way, FCP can store multiple versions of your project and give you the option of recovering different stages in your edit.

Note

Despite all its benefits and functionality, you should use the Autosave Vault to augment your manual backup routine rather than replace it.

Setting up your Autosave Vault is a two-step process: specifying the location and setting the interval between each save and the number of iterations to be kept.

Lesson 12, you'll learn how to use the Restore feature to select and open archived projects.

Managing Memory Resources

One way to maximize performance in FCP is to limit the use of virtual memory by Mac OS X. The first step is to make sure that you have enough RAM installed in your system to support your workflow. Then you can use memory management features in Final Cut Pro to allocate memory, as it is required.

Memory and Cache Settings

Memory resources are configured using the Memory & Cache tab of the System Settings window. When you change the settings, you should choose values based on the needs of your workflow and customize settings for specific tasksevery time you assign more RAM to one feature, you'll reduce the amount allocated to other areas.

Levels of Undo

Final Cut Pro can support up to 99 levels of undo; the default is 10. The ability to undo actions is definitely usefulit's great to experiment and try things outbut working with a lot of levels can quickly become unwieldy. Final Cut Pro also needs to store each change you make to your project in case you want to step back; too many levels of

undo will begin to affect system performance.

Zero levels of undo would make the least demands on your system, but it's likely to interfere with your ability to work effectively. To optimize performance, limit the number of undo levels to something practicala setting that you actually use regularlyand integrate other tools, such as Revert and Restore, or techniques, such as incremental saves. At a certain point, creating new versions of your sequences becomes more efficient than testing ideas and undoing a multiple series of steps. The Autosave Vault and the Revert featureboth of which are covered in the next lessoncan also help you recover earlier versions of your project.

Recent Clips

The List Recent Clips preference controls the number of clips that appear in the Viewer's Recent Clips pop-up menu. The default value is 10 clips, and the maximum is 20. As with levels of undo, the way you work should guide your choice. FCP stores information in order to track each clip, so for optimum performance, you need to find a balance between what's practical and the allocation of system resources.

The only way to reset the Recent Clips pop-up without quitting FCP is to use the List Recent Clips setting in the

User Preferences window.

Establishing Real-Time Performance Levels

Though real-time performance is ultimately determined by your system configuration, the filters you're working with, and the amount of memory currently assigned to Final Cut Pro, a number of tools and strategies can help you make the most of your existing hardware.

Optimizing RT Video Performance

The technology that drives real-time performance in Final Cut Pro is called

RT Extreme ; it's intended to remove the need to render effects while you edit. There are a range of RT Extreme settings that modify the way FCP will handle video performance. Exactly how you should set up your system depends very much on your hardware and the needs of your particular workflow. If your system is fast enough, you'll be able to play several streams of high-resolution video, or apply a series of high-quality filters, effects, titles, and transitions without affecting your ability to play back your video in real-time. On smaller systems, such as a PowerBook G4, you'll be able to make use of the different quality settings to preview complex edits and effects. You need to understand the different options, and you should test real-time performance to develop a complete profile of the full capabilities of your system.

In the following exercise, you'll configure FCP to display the highest-quality video. Once you've established the extent of your system's capabilities, you can begin to modify each setting to increase real-time performance.

More Info

Not all codecs support playback by RT Extreme. Refer to the Supported RT Extreme Playback Codecs section of the FCP user's manual for additional details.

Once you've established how many real-time video tracks your system can support at the highest quality settings, you can repeat the test using different configurations to create a complete profile of your system's real-time performance.

Testing Video Filters

The performance of real-time effects is based on your hardware configuration, including CPU speed, RAM, third-party video acceleration, and external playback. It also depends on the video format you're working with, your current RT settings, and which filters you're using. Some video filters require more processing power than others. RT Extreme can also be used to increase real-time performance when you're working with filters to reduce the amount of rendering you need to do. When you do need to render, there are some steps that limit the time you spend rendering.

Once you've established how many Gaussian Blur filters you can apply to a clip and still play back a high-quality image in real time, you can duplicate the test with different RT settings and other filters to fully understand how your system performs.

Note

When you do need to render, you can use Final Cut Pro's Auto Render feature (located under the General tab in the System Preferences window) to make the most efficient use of your time. With the Auto Render options turned on, your computer will render sequences while you're away from your computer.

Hardware Accelerators

As an alternative to the software-based RT Extreme engine, you can also improve real-time performance by using third-party hardware accelerators. (Refer to the PCI cards section of the hardware and interfaces lesson for details on individual cards.)

Optimizing RT Audio Performance

The Real-time Audio Mixing preference enables you to set the maximum number of individual tracks you can mix in real-timegiven the necessary hardware support. Once that limit has been exceeded, you'll need to render your audio before you can play it. By working with this setting judiciously, you'll be able to control the way audio is handled in FCP and reduce or increase performance as your workflow requires.

More Info

See the "Real-Time Audio and Video Options" section of the Final Cut Pro user's manual for specific information about differences between the Audio Playback Quality settings.

As with video performance, simply adding tracks to the Real-time Audio Mixing preference doesn't override the fundamental fact that real-time performance is determined by your hardware and the complexity of your work. Before you embark on a project, you should run some performance tests to fully appreciate how your system performs.

As with video performance, once you've determined how many real-time audio tracks your system can support at the High setting, you should repeat the test at different Audio Playback Quality options to develop a profile of your system performance.

Testing Audio Filters

As you begin to apply filters and transitions, real-time performance will be affected by the additional demands they place on your system. You'll see the red audio render bar and hear a series of beeps when FCP needs to render your audio. The Beep When Playing Unrendered Audio check box in the Playback Control tab of System Settings toggles the beeps on and off.

Tip

Render video effects and audio filters, or use the Mixdown command, to further optimize real-time performance.

Like video filters, different audio filters require varying amounts of processing power, and they'll affect your system's real-time performance when you work with them. In terms of CPU usage and your system configuration, individual filters can sometimes occupy the equivalent of several real-time tracks.

The exact number of real-time tracks the filter requires varies from system to system. Remove the filter and repeat the test with other individual filters to see the demands that they will place on your system and how they will affect real-time performance.

Note

If FCP is performing high quality conversions on your audio clips, it will also increase the demands on your system and reduce RT performance. Use a low quality setting or standardize your files using QuickTime Conversion.

Audio Outputs

Depending on your hardware configuration, you may need to customize FCP's Audio Output settings to match your setup and workflow. If you have the appropriate hardware, FCP can output up to 24 discrete tracks of audio. Once you have connected your output device, you assign outputs in either User Preferences (to create universal settings) or Sequence Settings (to define outputs for individual sequences).

Note

Your audio device must support Core Audio or have a compatible Core Audio driver.