When Adobe Media Encoder imports video and audio in some formats, it processes and caches versions of these items that it can readily access. Imported audio files are each conformed to a new .cfa file, and MPEG files are indexed to a new .mpgindex file.
When you first import a file, you may experience a delay while the media is being processed and cached.
A database retains links to each of the cached media files. This media cache database is shared with Adobe Media Encoder, Adobe Premiere Pro, and After Effects so that each of these applications can each read from and write to the same set of cached media files. If you change the location of the database from within any of these applications, the location is updated for other applications, too. Each application can use its own cache folder, but the same database keeps track of them all.
You can change the locations of the media cache database and the cached files using Edit>Preferences>Media>Media Cache Files. For more information, see Preferences.)
To change the location of the media cache database or the media cache itself, click one of the Browse buttons in the Media preferences.
To remove conformed and indexed files from the cache and to remove their entries from the database, click Clean. This command only removes files associated with items for which the source file is no longer available.
Before you click the Clean button, make sure that any storage devices that contain your currently used source media are connected to your computer. If the footage is determined to be missing because the storage device on which it is located is not connected, the associated files in the media cache will be removed. Following this, you would need to reconform or re-index the footage when you attempt to use the footage later.
Cleaning the database and cache using the Clean button does not remove files that are associated with footage items for which the source files are still available. To manually remove the conformed files and index files, navigate to the media cache folder and delete the files. The location of the media cache folder is shown in the Media preferences. If the path is truncated, click the Browse button to show the path.