I almost didn't believe you there! https://developer.apple.com/documentation/coremedia/1489454-cmmetadataformatdescriptioncreat https://developer.apple.com/doc

I almost didn't believe you there! https://developer.apple.com/documentation/coremedia/1489454-cmmetadataformatdescriptioncreat https://developer.apple.com/documentation/coremedia/1489454-... "Creates a metadata format description by extending an existing description with the values you specify." The description doesn't sound so bad...