Editing Video > Previewing a video program > Working with preview files
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Working with preview files


When you preview a program, Premiere creates temporary files on your hard disk. These preview files contain the results of any effects that Premiere processed during a preview. If you preview the same work area more than once without making any changes, Premiere instantly plays back the preview files instead of processing the Timeline again. Similarly, preview files can save time when you export the final video program by using the processed effects already stored. Premiere stores the preview files in a folder you can specify.

To further save time, Premiere maintains existing preview files whenever possible. Preview files move along with their associated segment of the Timeline as you edit your project. When a segment of the Timeline is changed, Premiere automatically trims the corresponding preview file, saving the remaining unchanged segment.

The preview status for each clip in the Timeline window is indicated by a colored bar above the time ruler. When a preview file doesn't exist for a segment and needs to be generated, the indicator bar above that segment is red. When a preview file for the video segment exists, the indicator bar is green. When a preview for the audio segment exists, an additional bar attached below the indicator bar is light green. If all effects in a segment can be played in real time, there is no colored bar.

Note: To find the properties for audio preview files, choose Project > Project Settings > Audio. For information on audio project settings, see Audio settings.

To specify the disk location for preview files:

1 Choose Edit > Preferences > Scratch Disks/Device Control.

2 For the Video Previews and Audio Previews menus in the Scratch Disks section, choose a location for video and audio preview temporary files, respectively. The disk you choose must be large and fast enough to support video playback, so choose a hard disk attached to your computer, not a network drive. Also, because Premiere must be able to locate the preview files when you open a project, avoid specifying removable media.

3 Click OK.

To delete preview files:

Do one of the following:
  • To delete all preview files, move the cursor to the indicator bar while holding down Ctrl+Alt+Shift (Windows) or Command+Option+Shift (Mac OS). Click the indicator bar when the cursor becomes a trash can.
  • To delete video preview files only, move the cursor to the indicator bar while holding down Ctrl+Alt (Windows) or Command+Option (Mac OS). Click the indicator bar when the cursor becomes a trash can labelled with the letter "V."
  • To delete audio preview files only, move the cursor to the indicator bar while holding down Ctrl+Shift (Windows) or Command+Shift (Mac OS). Click the indicator bar when the cursor becomes a trash can labelled with the letter "A."

    • Editing Video > Previewing a video program > Working with preview files