Gets the size of a user data item in an audio file.
- iOS 2.0+
- macOS 10.4+
- Mac Catalyst 13.0+
- tvOS 9.0+
The audio file whose user data item size you want.
The four-character code of the designated user data item.
An index specifying which user data item with the four-character code specified in the
inparameter you want to query.
User Data ID
On output, a pointer the size of the user data item.
A result code. See Result Codes.
In the context of this function, user data refers to chunks in AIFF, CAF, and WAVE files, to resources in Sound Designer II files, and possibly to other types of information in other files.