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# Clean Aperture Extension Constants

Constants that identify clean aperture extensions.

## Topics

### Constants

[`let kCMFormatDescriptionKey_CleanApertureHeight: CFString`](/documentation/CoreMedia/kCMFormatDescriptionKey_CleanApertureHeight-swift.var)

A key that identifies the clean aperture height value.

[`let kCMFormatDescriptionKey_CleanApertureHeightRational: CFString`](/documentation/CoreMedia/kCMFormatDescriptionKey_CleanApertureHeightRational)

A key that identifies the clean aperture height rational value.

[`let kCMFormatDescriptionKey_CleanApertureHorizontalOffset: CFString`](/documentation/CoreMedia/kCMFormatDescriptionKey_CleanApertureHorizontalOffset-swift.var)

A key that describes the clean aperture height horizontal offset value.

[`let kCMFormatDescriptionKey_CleanApertureHorizontalOffsetRational: CFString`](/documentation/CoreMedia/kCMFormatDescriptionKey_CleanApertureHorizontalOffsetRational)

A key that identifies the clean aperture horizontal offset rational value.

[`let kCMFormatDescriptionKey_CleanApertureVerticalOffset: CFString`](/documentation/CoreMedia/kCMFormatDescriptionKey_CleanApertureVerticalOffset-swift.var)

A key that identifies the clean aperture vertical offset value.

[`let kCMFormatDescriptionKey_CleanApertureVerticalOffsetRational: CFString`](/documentation/CoreMedia/kCMFormatDescriptionKey_CleanApertureVerticalOffsetRational)

A key that identifies the clean aperture vertical offset rational value.

[`let kCMFormatDescriptionKey_CleanApertureWidth: CFString`](/documentation/CoreMedia/kCMFormatDescriptionKey_CleanApertureWidth-swift.var)

A key that identifies the clean aperture width value.

[`let kCMFormatDescriptionKey_CleanApertureWidthRational: CFString`](/documentation/CoreMedia/kCMFormatDescriptionKey_CleanApertureWidthRational)

A key that identifies the clean aperture width rational value.


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