extensions A dictionary that contains all of the extensions. Declarationvar extensions: CMFormatDescription.Extensions { get } See AlsoInspecting Format DescriptionsaudioFormatListaudioStreamBasicDescriptionaudioChannelLayoutdimensionsframeDurationframeQuantaidentifiersmagicCookiemediaSubTypemediaTypemostCompatibleFormatnalUnitHeaderLengthparameterSetsrichestDecodableFormattimeCodeFlags