---
title: AVCompositionTrackSegment
framework: avfoundation
role: symbol
role_heading: Class
path: avfoundation/avcompositiontracksegment
---

# AVCompositionTrackSegment

A track segment that maps a time from the source media track to the composition track.

## Declaration

```swift
class AVCompositionTrackSegment
```

## Overview

Overview You typically use this class to save a low-level representation of a composition.

## Topics

### Creating a segment

- [init(timeRange:)](avfoundation/avcompositiontracksegment/init(timerange:).md)
- [init(url:trackID:sourceTimeRange:targetTimeRange:)](avfoundation/avcompositiontracksegment/init(url:trackid:sourcetimerange:targettimerange:)-4rc2g.md)

### Accessing segment properties

- [sourceURL](avfoundation/avcompositiontracksegment/sourceurl.md)
- [sourceTrackID](avfoundation/avcompositiontracksegment/sourcetrackid.md)
- [isEmpty](avfoundation/avcompositiontracksegment/isempty.md)

### Initializers

- [init(URL:trackID:sourceTimeRange:targetTimeRange:)](avfoundation/avcompositiontracksegment/init(url:trackid:sourcetimerange:targettimerange:)-9shbx.md)
- [init(URL:trackID:sourceTimeRange:targetTimeRange:)](avfoundation/avcompositiontracksegment/init(url:trackid:sourcetimerange:targettimerange:)-qoz.md)

## Relationships

### Inherits From

- [AVAssetTrackSegment](avfoundation/avassettracksegment.md)

### Conforms To

- [CVarArg](swift/cvararg.md)
- [CustomDebugStringConvertible](swift/customdebugstringconvertible.md)
- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)
- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)

## See Also

### Compositions

- [AVComposition](avfoundation/avcomposition.md)
- [AVCompositionTrack](avfoundation/avcompositiontrack.md)