extraAttributes
A dictionary of additional attributes for a metadata item.
Declaration
var extraAttributes: [AVMetadataExtraAttributeKey : Any]? { get }Discussion
Extra attributes, when they’re present, are specific to metadata container formats and keys in their associated key-spaces. For example, a metadata item can represent the “attached picture” frame defined by the ID3 tag specification with keyspace id3 and key id3MetadataKeyAttachedPicture, a value that carries the image data, and extra attributes that include a description of the picture as carried in the ‘APIC’ frame of the ID3 tag.