---
title: overallDurationHint
framework: avfoundation
role: symbol
role_heading: Instance Property
path: avfoundation/avcomposition/overalldurationhint
---

# overallDurationHint

The total duration of fragments that currently exist, or may exist in the future.

## Declaration

```swift
var overallDurationHint: CMTime { get }
```

## Discussion

Discussion For QuickTime movie files and MPEG-4 files, the asset retrieves this value from the mehd box of the mvex box, if present. If no total fragment duration hint is available, the value of this property is invalid.

## See Also

### Determining fragment support

- [canContainFragments](avfoundation/avcomposition/cancontainfragments.md)
- [containsFragments](avfoundation/avcomposition/containsfragments.md)