# AudioFormatGetProperty(_:_:_:_:_:) Gets the value of an audio format property. ``` func AudioFormatGetProperty(_ inPropertyID: AudioFormatPropertyID, _ inSpecifierSize: UInt32, _ inSpecifier: UnsafeRawPointer?, _ ioPropertyDataSize: UnsafeMutablePointer?, _ outPropertyData: UnsafeMutableRawPointer?) -> OSStatus ``` ## Parameters `inPropertyID` An [`AudioFormatPropertyID`](/documentation/AudioToolbox/AudioFormatPropertyID) constant. For a list of these constants, see [Audio Format Property Identifiers](/documentation/AudioToolbox/1577853-audio-format-property-identifier). `inSpecifierSize` The size of the specifier data. `inSpecifier` A buffer of data used as an input argument for querying some of the properties. `ioPropertyDataSize` On input, the size of the `outPropertyData` buffer. On output, the number of bytes written to the buffer. `outPropertyData` The buffer to write the property data to. If the `outPropertyData` parameter is `NULL` and `ioPropertyDataSize` is not `NULL`, the amount that would have been written is reported. ## Return Value A result code. Returns `noErr` if successful. ## Discussion Some Core Audio property values are C types and others are Core Foundation objects. If you call this function to retrieve a value that is a Core Foundation object, then this function—despite the use of “Get” in its name—duplicates the object. You are responsible for releasing the object, as described in [The Create Rule](https://developer.apple.com/library/archive/documentation/CoreFoundation/Conceptual/CFMemoryMgmt/Concepts/Ownership.html#//apple_ref/doc/uid/20001148-103029) in [Memory Management Programming Guide for Core Foundation](https://developer.apple.com/library/archive/documentation/CoreFoundation/Conceptual/CFMemoryMgmt/CFMemoryMgmt.html#//apple_ref/doc/uid/10000127i). --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)