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# AVCaptureVideoDataOutputSampleBufferDelegate

Methods for receiving sample buffers from, and monitoring the status of, a video data output.

```
protocol AVCaptureVideoDataOutputSampleBufferDelegate : NSObjectProtocol
```

## Overview

This protocol defines an interface for delegates of an [`AVCaptureVideoDataOutput`](/documentation/AVFoundation/AVCaptureVideoDataOutput) object to receive captured video sample buffers and be notified of late sample buffers that were dropped.

The delegate of an [`AVCaptureVideoDataOutput`](/documentation/AVFoundation/AVCaptureVideoDataOutput) object must adopt the `AVCaptureVideoDataOutputSampleBufferDelegate` protocol. The methods in this protocol are optional.

## Topics

### Managing sample buffer behavior

[`captureOutput(_:didOutput:from:)`](/documentation/AVFoundation/AVCaptureVideoDataOutputSampleBufferDelegate/captureOutput(_:didOutput:from:))

Notifies the delegate that a new video frame was written.

[`captureOutput(_:didDrop:from:)`](/documentation/AVFoundation/AVCaptureVideoDataOutputSampleBufferDelegate/captureOutput(_:didDrop:from:))

Notifies the delegate that a video frame was discarded.


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