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# AVCaptionSettingsKey

A structure that defines dictionary keys to configure the caption converter and validator.

```
struct AVCaptionSettingsKey
```

## Topics

### Keys

[`mediaType`](/documentation/AVFoundation/AVCaptionSettingsKey/mediaType)

A key that identifies the output media type of a caption conversion operation.

[`mediaSubType`](/documentation/AVFoundation/AVCaptionSettingsKey/mediaSubType)

A key that identifies the output media subtype of a caption conversion operation.

[`timeCodeFrameDuration`](/documentation/AVFoundation/AVCaptionSettingsKey/timeCodeFrameDuration)

A key that identifies the frame duration that the system uses for the time code.

[`useDropFrameTimeCode`](/documentation/AVFoundation/AVCaptionSettingsKey/useDropFrameTimeCode)

A key that identifies whether the system uses drop frame time code.

### Initializers

[`init(rawValue:)`](/documentation/AVFoundation/AVCaptionSettingsKey/init(rawValue:))

Creates a settings key with a string.


---

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