This directory contains three Xcode config files that are used to setup certain build variables and some entries in the various Info.plist files that help define the frameworks and AUv3 app extensions. The Common.xcconfig file holds the common settings, all having to do with configuring the audio unit component that is embedded in the macOS and iOS app extensions. The Dev.xcconfig and Staging.xcconfig files include the Common.xcconfig and then define their own customizations.

Here are the elements in the Common.xcconfig and their reason for being:

• AU_BASE_NAME (LPF) — defines the display name for bundles; app extensions will have " AUv3" appended to it
• AU_COMPONENT_NAME (B-Ray: Low-pass) — defines the audio unit component name which by convention is made up of the manufacturer name and the audio unit name separated by a ':'
• AU_COMPONENT_TYPE (aufx) — the value for the componentType attribute in the AudioComponentDescription object. The value aufx indicates an audio effects unit.
• AU_COMPONENT_SUBTYPE (lpas) — the value for the componentSubType attribute in the AudioComponentDescription object.
• AU_COMPONENT_MANUFACTURER (BRay) — the value for the componentManufacturer attribute in the AudioComponentDescription object. This is the unique identifier for the entity that is distributing the audio unit, and according to Apple it cannot be all lower-case.
• AU_FACTORY_FUNCTION (LowPassFilterFramework.FilterViewController) — identifies the bundle path to the entity that derives from AUAudioUnitFactory protocol for creating new audio unit entities from an AudioComponentDescription