Dividing or Deleting Sections of Source Clips Before Editing

Before you edit your media in Final Cut Pro, you have the option of further dividing or eliminating parts of source clips. If you used a batch capture list and device control for capturing, you may have captured your source clip files exactly as you want them. On the other hand, you may feel that the captured source clips need to be broken down into individual takes, or you may want to eliminate some of the content you captured before you begin editing in order to make efficient use of available disk space.

Strategies for Breaking Down Source Clips Before Editing

Before you begin, if the edge code number-to-timecode relationship is not continuous throughout the camera roll from which a source clip came, be aware that there are a couple of important things you need to do after you break down source clips:

  • Create a new database record for the new source clip that is created when you break down a clip, and make sure the new source clip is connected to the database record.

  • Update the clip’s database record so that the edge code number information is correct for the clip’s new first frame. (This is necessary only if you delete material from the beginning of a clip.)

    Note: See Is Your Edge Code Number-to-Timecode Relationship Continuous or Noncontinuous? for more information.

There are a variety of ways to break down source clips before editing:

  • An easy way to break source clip files into smaller source clips is to use Final Cut Pro. First, make one or more subclips from the clip in the Browser. You can then use the Media Manager to delete any part of the clip that you did not select as a subclip. See the section about creating and working with subclips in the Final Cut Pro documentation for more information.

  • Another way to select and save portions of a clip is to use QuickTime Pro. If you use QuickTime Pro for this purpose, make sure to choose “Make movie self-contained” in the “Save as” dialog. See The Difference Between Self-Contained and Reference Media Files for more information.

  • If you are using hole-punched or otherwise marked frames (rather than window burn) to identify the key numbers for each of your source clips, make sure you do not trim off any of the marked frames.

  • If the telecine transfer involved the 3:2 pull-down method, it’s a good idea to start each source clip on an A frame. After the 3:2 pull-down, A frames are the only film frames that are not divided into two video frames. Because of this and because the A frame is the start of the video five-frame pattern, it is preferable to have one as the first frame in all video clips. See About A Frames for more information.

The Difference Between Self-Contained and Reference Media Files

There are two basic video and audio file types that you need to be aware of, especially if you are breaking a large media file into smaller ones using QuickTime Pro. Because video files tend to be large, the type of media file you create can have a large impact on your hard disk space.

  • Self-contained media files: A self-contained media file is complete; you can delete the original file and its duplicate will still play on its own. For that reason, self-contained media files are typically large files. It’s a good idea to save your media as self-contained if you intend not to use large portions of the original, and then you can delete the original once you have saved the bits you want.
  • Reference media files: A reference media file is a file with dependencies on the original media file. Reference files do not contain any actual media content—they contain only pointers to a specific part of the original media file. The files for these clips are small. If you delete, move, or rename the original media file, any files that refer to it will no longer play, because they cannot locate the original.

One way to tell if a media file is self-contained or reference is to open it in the Cinema Tools Clip window and click the Analysis button. The Analysis pane displays this information. Another way to tell is to look at its file size—media files with dependencies have small (20 kilobyte or so) file sizes, whereas self-contained media files, even short ones, can have file sizes up to hundreds of megabytes or more.

Deleting a Source Clip File

To eliminate an unwanted source clip file before you start editing, drag the clip to the Trash. Then, if there is a record for that clip in the Cinema Tools database, delete that database record. Refer to Deleting a Database Record for more information.