---
title: "CMBufferQueueGetFirstPresentationTimeStamp(_:)"
framework: coremedia
role: symbol
role_heading: Function
path: "coremedia/cmbufferqueuegetfirstpresentationtimestamp(_:)"
---

# CMBufferQueueGetFirstPresentationTimeStamp(_:)

Gets the presentation timestamp of the first buffer in a buffer queue.

## Declaration

```swift
func CMBufferQueueGetFirstPresentationTimeStamp(_ queue: CMBufferQueue) -> CMTime
```

## Parameters

- `queue`: CMBufferQueue being interrogated.

## Return Value

Return Value The presentation timestamp of the first buffer in the interrogated CMBufferQueue.

## Discussion

Discussion This API is is a faster alternative to CMBufferQueueTestTrigger(_:triggerToken:),                but only works if you know your queue is sorted by presentation                timestamp. If the getPresentationTimeStamp callback is NULL,                kCMTimeInvalid will be returned.

## See Also

### Inspecting Duration and Timing

- [CMBufferQueueGetDuration(_:)](coremedia/cmbufferqueuegetduration(_:).md)
- [CMBufferQueueGetMinDecodeTimeStamp(_:)](coremedia/cmbufferqueuegetmindecodetimestamp(_:).md)
- [CMBufferQueueGetFirstDecodeTimeStamp(_:)](coremedia/cmbufferqueuegetfirstdecodetimestamp(_:).md)
- [CMBufferQueueGetMinPresentationTimeStamp(_:)](coremedia/cmbufferqueuegetminpresentationtimestamp(_:).md)
- [CMBufferQueueGetEndPresentationTimeStamp(_:)](coremedia/cmbufferqueuegetendpresentationtimestamp(_:).md)
- [CMBufferQueueGetMaxPresentationTimeStamp(_:)](coremedia/cmbufferqueuegetmaxpresentationtimestamp(_:).md)
- [CMBufferQueueGetCallbacksForSampleBuffersSortedByOutputPTS()](coremedia/cmbufferqueuegetcallbacksforsamplebufferssortedbyoutputpts().md)
- [CMBufferQueueGetCallbacksForUnsortedSampleBuffers()](coremedia/cmbufferqueuegetcallbacksforunsortedsamplebuffers().md)