# Core Media Constants ## Overview This document describes constants defined in the Core Media framework not defined elsewhere in this reference. ## Topics ### Constants [`var COREMEDIA_DECLARE_BRIDGED_TYPES: Bool`](/documentation/CoreMedia/COREMEDIA_DECLARE_BRIDGED_TYPES) [`var COREMEDIA_DECLARE_NULLABILITY: Bool`](/documentation/CoreMedia/COREMEDIA_DECLARE_NULLABILITY) [`var COREMEDIA_DECLARE_NULLABILITY_BEGIN_END: Bool`](/documentation/CoreMedia/COREMEDIA_DECLARE_NULLABILITY_BEGIN_END) [`var COREMEDIA_DECLARE_RETURNS_NOT_RETAINED_ON_PARAMETERS: Bool`](/documentation/CoreMedia/COREMEDIA_DECLARE_RETURNS_NOT_RETAINED_ON_PARAMETERS) [`var COREMEDIA_DECLARE_RETURNS_RETAINED: Bool`](/documentation/CoreMedia/COREMEDIA_DECLARE_RETURNS_RETAINED) [`var COREMEDIA_DECLARE_RETURNS_RETAINED_ON_PARAMETERS: Bool`](/documentation/CoreMedia/COREMEDIA_DECLARE_RETURNS_RETAINED_ON_PARAMETERS) [`var COREMEDIA_USE_DERIVED_ENUMS_FOR_CONSTANTS: Bool`](/documentation/CoreMedia/COREMEDIA_USE_DERIVED_ENUMS_FOR_CONSTANTS) [`var CMITEMCOUNT_MAX: Int`](/documentation/CoreMedia/CMITEMCOUNT_MAX) [`var COREMEDIA_CMBASECLASS_VERSION_IS_POINTER_ALIGNED: Bool`](/documentation/CoreMedia/COREMEDIA_CMBASECLASS_VERSION_IS_POINTER_ALIGNED) [`var COREMEDIA_DECLARE_RELEASES_ARGUMENT: Bool`](/documentation/CoreMedia/COREMEDIA_DECLARE_RELEASES_ARGUMENT) [`var COREMEDIA_FALSE: Bool`](/documentation/CoreMedia/COREMEDIA_FALSE) [`var COREMEDIA_TRUE: Bool`](/documentation/CoreMedia/COREMEDIA_TRUE) [`var COREMEDIA_USE_ALIGNED_CMBASECLASS_VERSION: Bool`](/documentation/CoreMedia/COREMEDIA_USE_ALIGNED_CMBASECLASS_VERSION) [`var CMTIMEBASE_USE_SOURCE_TERMINOLOGY: Int32`](/documentation/CoreMedia/CMTIMEBASE_USE_SOURCE_TERMINOLOGY) [`var COREMEDIA_DECLARE_RETURNS_RETAINED_BLOCK: Bool`](/documentation/CoreMedia/COREMEDIA_DECLARE_RETURNS_RETAINED_BLOCK) [`let kCMFormatDescriptionExtension_ProjectionKind: CFString`](/documentation/CoreMedia/kCMFormatDescriptionExtension_ProjectionKind) [`let kCMFormatDescriptionExtension_ViewPackingKind: CFString`](/documentation/CoreMedia/kCMFormatDescriptionExtension_ViewPackingKind) [`let kCMFormatDescriptionLogTransferFunction_AppleLog: CFString`](/documentation/CoreMedia/kCMFormatDescriptionLogTransferFunction_AppleLog) [`let kCMFormatDescriptionProjectionKind_Rectilinear: CFString`](/documentation/CoreMedia/kCMFormatDescriptionProjectionKind_Rectilinear) [`let kCMFormatDescriptionViewPackingKind_OverUnder: CFString`](/documentation/CoreMedia/kCMFormatDescriptionViewPackingKind_OverUnder) [`let kCMFormatDescriptionViewPackingKind_SideBySide: CFString`](/documentation/CoreMedia/kCMFormatDescriptionViewPackingKind_SideBySide) [`let kCMMetadataDataType_QuickTimeMetadataMilliLux: CFString`](/documentation/CoreMedia/kCMMetadataDataType_QuickTimeMetadataMilliLux) [`let kCMMetadataDataType_QuickTimeMetadataUUID: CFString`](/documentation/CoreMedia/kCMMetadataDataType_QuickTimeMetadataUUID) [`let kCMMetadataIdentifier_QuickTimeMetadataSceneIlluminance: CFString`](/documentation/CoreMedia/kCMMetadataIdentifier_QuickTimeMetadataSceneIlluminance) [`let kCMMetadataIdentifier_QuickTimeMetadataSegmentIdentifier: CFString`](/documentation/CoreMedia/kCMMetadataIdentifier_QuickTimeMetadataSegmentIdentifier) [`let kCMSampleAttachmentKey_HDR10PlusPerFrameData: CFString`](/documentation/CoreMedia/kCMSampleAttachmentKey_HDR10PlusPerFrameData) [`let kCMTagProjectionTypeHalfEquirectangular: __CMTag`](/documentation/CoreMedia/kCMTagProjectionTypeHalfEquirectangular) [`let kCMTextMarkupAttribute_FontFamilyNameList: CFString`](/documentation/CoreMedia/kCMTextMarkupAttribute_FontFamilyNameList) [`let kCMFormatDescriptionExtension_ConvertedFromExternalSphericalTags: CFString`](/documentation/CoreMedia/kCMFormatDescriptionExtension_ConvertedFromExternalSphericalTags) [`let kCMFormatDescriptionProjectionKind_AppleImmersiveVideo: CFString`](/documentation/CoreMedia/kCMFormatDescriptionProjectionKind_AppleImmersiveVideo) [`let kCMFormatDescriptionProjectionKind_Equirectangular: CFString`](/documentation/CoreMedia/kCMFormatDescriptionProjectionKind_Equirectangular) [`let kCMFormatDescriptionProjectionKind_HalfEquirectangular: CFString`](/documentation/CoreMedia/kCMFormatDescriptionProjectionKind_HalfEquirectangular) [`let kCMFormatDescriptionProjectionKind_ParametricImmersive: CFString`](/documentation/CoreMedia/kCMFormatDescriptionProjectionKind_ParametricImmersive) [`let kCMMetadataBaseDataType_ExtendedRasterRectangleValue: CFString`](/documentation/CoreMedia/kCMMetadataBaseDataType_ExtendedRasterRectangleValue) [`let kCMMetadataBaseDataType_RasterRectangleValue: CFString`](/documentation/CoreMedia/kCMMetadataBaseDataType_RasterRectangleValue) [`let kCMMetadataIdentifier_QuickTimeMetadataDisplayMaskRectangleMono: CFString`](/documentation/CoreMedia/kCMMetadataIdentifier_QuickTimeMetadataDisplayMaskRectangleMono) [`let kCMMetadataIdentifier_QuickTimeMetadataDisplayMaskRectangleStereoLeft: CFString`](/documentation/CoreMedia/kCMMetadataIdentifier_QuickTimeMetadataDisplayMaskRectangleStereoLeft) [`let kCMMetadataIdentifier_QuickTimeMetadataDisplayMaskRectangleStereoRight: CFString`](/documentation/CoreMedia/kCMMetadataIdentifier_QuickTimeMetadataDisplayMaskRectangleStereoRight) [`let kCMMetadataIdentifier_QuickTimeMetadataPresentationImmersiveMedia: CFString`](/documentation/CoreMedia/kCMMetadataIdentifier_QuickTimeMetadataPresentationImmersiveMedia) [`let kCMMetadataIdentifier_QuickTimeMetadataSpatialAudioMix: CFString`](/documentation/CoreMedia/kCMMetadataIdentifier_QuickTimeMetadataSpatialAudioMix) [Camera calibration](/documentation/CoreMedia/camera-calibration-constants) Constants that identify camera calibration extensions. ### Type Aliases [`typealias CMBaseClassVersion`](/documentation/CoreMedia/CMBaseClassVersion) [`typealias CMStructVersion`](/documentation/CoreMedia/CMStructVersion) --- Copyright © 2026 Apple Inc. 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