Sessions & Tracks : Importing and Exporting Session Data : Audio Conversion on Import

Audio Conversion on Import
For more information, see the following topics:
Depending on the properties of the audio files you are importing, you can add, copy, or convert the files:
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When files are added to a Pro Tools session, they remain at their current hard drive location and are not moved or copied. The session references the original files wherever they are on your system. Additionally, the files referenced by the session retain their original file format, sample rate, and bit depth.
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When files are copied into the session, the original files remain wherever they are on your system and are copied to the session’s Audio Files folder and are then added to the session. The session references the copied files, not the original files. Additionally, the copied files referenced by the session retain their original file format, sample rate, and bit depth.
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When files are converted into the session, the original files remain wherever they are on your system, converted to the session file format, sample rate, and bit depth, and are written to the session’s Audio Files folder. The session references the converted files, not the original files.
Files that Can Be Added to a Session without Conversion
Any audio file of a supported file format (WAV and AIFF) and bit depth (16, 24, and 32-bit float) can be added to sessions without conversion. Audio files with sample rates that do not match the session sample rate can be added to the session without conversion, but will playback at a different pitch and speed from files that match the session sample rate.
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You can enable the Automatically Copy Files on Import option in the Processing Preferences page to be sure to always copy files to the session’s Audio Files folder when importing audio by drag and drop.
Files that Must Be Converted on Import
Audio files formats other than WAV and AIFF must be converted on import. Pro Tools automatically converts these files to the current session file format on import. Also, if the session is not enabled for Interleaved files, Pro Tools splits interleaved audio files into multiple mono files on import.
If clip definitions are present in an audio file, you can convert and import the audio for a clip without importing the entire parent audio file using the Import Audio command.
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Pro Tools 7.x and higher does not support audio file names that contain certain ASCII characters (see Opening a Session that Contains Audio File Names with Illegal Characters).