Gets the number of user data items with a specified ID in a file.
- iOS 2.0+
- macOS 10.4+
- Mac Catalyst 13.0+
- tvOS 9.0+
The audio file whose user data items are to be counted.
The four-character code (such as
COMM) of the user data item.
On output, a pointer to the number of user data items of this type in the file.
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.