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# kVTCompressionPropertyKey_MaxKeyFrameIntervalDuration

The maximum duration from one key frame to the next in seconds.

```
let kVTCompressionPropertyKey_MaxKeyFrameIntervalDuration: CFString
```

## Discussion

The default value is `0`, which means no limit.  This property is particularly useful when the frame rate is variable. See [`kVTCompressionPropertyKey_MaxKeyFrameIntervalDuration`](/documentation/VideoToolbox/kVTCompressionPropertyKey_MaxKeyFrameIntervalDuration) for more discussion of key frames.

This key can be set in conjunction with [`kVTCompressionPropertyKey_MaxKeyFrameIntervalDuration`](/documentation/VideoToolbox/kVTCompressionPropertyKey_MaxKeyFrameIntervalDuration), which requires a keyframe every `X` frames or every `Y` seconds, whichever comes first.

---

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