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# AVAssetReaderOutput

An abstract class that defines the interface to read media samples from an asset reader.

```
class AVAssetReaderOutput
```

## Overview

You add concrete output instances, such as [`AVAssetReaderTrackOutput`](/documentation/AVFoundation/AVAssetReaderTrackOutput) or [`AVAssetReaderVideoCompositionOutput`](/documentation/AVFoundation/AVAssetReaderVideoCompositionOutput), to an asset reader to perform specific tasks.

> Important:
> If you don’t require modifying sample data in-place, set the value of the ``doc://com.apple.avfoundation/documentation/AVFoundation/AVAssetReaderOutput/alwaysCopiesSampleData`` property to <doc://com.apple.documentation/documentation/Swift/false> to prevent the output from making unnecessary copies.

## Topics

### Configuring reading

[`alwaysCopiesSampleData`](/documentation/AVFoundation/AVAssetReaderOutput/alwaysCopiesSampleData)

A Boolean value that indicates whether the output vends copied sample data.

[`supportsRandomAccess`](/documentation/AVFoundation/AVAssetReaderOutput/supportsRandomAccess)

A Boolean value that indicates whether the output supports reconfiguring the time ranges it reads.

[`reset(forReadingTimeRanges:)`](/documentation/AVFoundation/AVAssetReaderOutput/reset(forReadingTimeRanges:))

Restarts reading with a new set of time ranges.

[`markConfigurationAsFinal()`](/documentation/AVFoundation/AVAssetReaderOutput/markConfigurationAsFinal())

Tells the output that it’s finished reconfiguring time ranges, and allows the asset reader to advance to a completed state.

### Copying sample buffers

[`copyNextSampleBuffer()`](/documentation/AVFoundation/AVAssetReaderOutput/copyNextSampleBuffer())

Copies the next sample buffer from the output.

[`AVAssetReaderOutput.Provider`](/documentation/AVFoundation/AVAssetReaderOutput/Provider)

An object that reads a collection of samples of a common media type from an asset reader.

[`AVAssetReaderOutput.RandomAccessController`](/documentation/AVFoundation/AVAssetReaderOutput/RandomAccessController)

Object used to reset an output provider to read specified time ranges.

[`AVAssetReaderOutput.SupportedPayload`](/documentation/AVFoundation/AVAssetReaderOutput/SupportedPayload)

### Inspecting the media type

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

The media type of samples that the output reads.


---

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