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# overallDurationHint

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

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

## 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 <doc://com.apple.documentation/documentation/CoreMedia/CMTime/invalid>.

---

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