---
title: getDuration
framework: coremedia
role: symbol
role_heading: Instance Property
path: coremedia/cmbuffercallbacks/getduration
---

# getDuration

This callback is called (once) during enqueue and dequeue operations to update the total duration of the queue.

## Declaration

```swift
var getDuration: CMBufferGetTimeCallback
```

## Discussion

Discussion This must not be NULL.

## See Also

### Properties

- [compare](coremedia/cmbuffercallbacks/compare.md)
- [CMBufferCompareCallback](coremedia/cmbuffercomparecallback.md)
- [CMBufferGetBooleanCallback](coremedia/cmbuffergetbooleancallback.md)
- [CMBufferGetTimeCallback](coremedia/cmbuffergettimecallback.md)
- [dataBecameReadyNotification](coremedia/cmbuffercallbacks/databecamereadynotification.md)
- [getDecodeTimeStamp](coremedia/cmbuffercallbacks/getdecodetimestamp.md)
- [getPresentationTimeStamp](coremedia/cmbuffercallbacks/getpresentationtimestamp.md)
- [getSize](coremedia/cmbuffercallbacks/getsize.md)
- [isDataReady](coremedia/cmbuffercallbacks/isdataready.md)
- [refcon](coremedia/cmbuffercallbacks/refcon.md)
- [version](coremedia/cmbuffercallbacks/version.md)