Gets the value of an audio unit property.
- iOS 2.0+
- macOS 10.0+
- Mac Catalyst 13.0+
- tvOS 9.0+
The audio unit that you want to get a property value from.
The identifier for the property.
The audio unit scope for the property.
The audio unit element for the property.
On successful output, the current value for the specified audio unit property. Set this parameter to
NULLwhen calling this function if you only want to determine how much memory to allocate for a variable size property.
On input, the expected size of the property value, as pointed to by the
outparameter. On output, the size of the data that was returned.
A result code.
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 in Memory Management Programming Guide for Core Foundation.