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# outputMediaDataWillChange(_:)

Tells the delegate that new samples are about to arrive.

```
optional func outputMediaDataWillChange(_ sender: AVPlayerItemOutput)
```

## Parameters

`sender`

The output object that sent the message.

## Discussion

You can use this method to prepare for any new sample data. This method is called at some point after a call to your video output object’s `requestNotificationOfMediaDataChangeWithAdvanceInterval:` method.

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