---
title: start()
framework: avfoundation
role: symbol
role_heading: Instance Method
path: avfoundation/avassetreader/start()
---

# start()

Prepares the reader to read media data from the asset.

## Declaration

```swift
func start() throws
```

## Discussion

Discussion note: An error if reading fails to start.

## See Also

### Controlling reading

- [startReading()](avfoundation/avassetreader/startreading().md)
- [cancelReading()](avfoundation/avassetreader/cancelreading().md)