Sync and Video : Working with Video in Pro Tools : Extracting Audio from QuickTime and Windows Media Video : Sample Rate Conversion Quality

Sample Rate Conversion Quality
If you import QuickTime audio that was not originally recorded at the session’s sample rate, the sample rate is converted to match the audio to your session. Pro Tools allows you to choose the quality of the sample rate conversion by means of the Conversion Quality setting in the Editing Preferences page.
There are five possible settings, ranging from Low (lowest quality) to Tweak Head (highest quality). The higher the quality of sample rate conversion, the longer it takes to convert the bounced file.
To set the sample rate conversion quality:
1 Choose Setup > Preferences and click the Processing tab.
2 Click the Conversion Quality pop-up menu and select a conversion setting.