---
title: "VTCompressionSessionCompleteFrames(_:untilPresentationTimeStamp:)"
framework: videotoolbox
role: symbol
role_heading: Function
path: "videotoolbox/vtcompressionsessioncompleteframes(_:untilpresentationtimestamp:)"
---

# VTCompressionSessionCompleteFrames(_:untilPresentationTimeStamp:)

Forces the compression session to complete the encoding of frames.

## Declaration

```swift
func VTCompressionSessionCompleteFrames(_ session: VTCompressionSession, untilPresentationTimeStamp completeUntilPresentationTimeStamp: CMTime) -> OSStatus
```

## Parameters

- `session`: The compression session.
- `completeUntilPresentationTimeStamp`: The timestamp at which to complete frame encoding.

## Discussion

Discussion If completeUntilPresentationTimeStamp is numeric, frames with presentation timestamps up to and including this timestamp are emitted before the function returns. If completeUntilPresentationTimeStamp is non-numeric, all pending frames are emitted before the function returns.

## See Also

### Encoding Frames

- [VTCompressionSessionGetPixelBufferPool(_:)](videotoolbox/vtcompressionsessiongetpixelbufferpool(_:).md)
- [VTCompressionSessionPrepareToEncodeFrames(_:)](videotoolbox/vtcompressionsessionpreparetoencodeframes(_:).md)
- [VTCompressionSessionEncodeFrame(_:imageBuffer:presentationTimeStamp:duration:frameProperties:sourceFrameRefcon:infoFlagsOut:)](videotoolbox/vtcompressionsessionencodeframe(_:imagebuffer:presentationtimestamp:duration:frameproperties:sourceframerefcon:infoflagsout:).md)
- [VTCompressionSessionEncodeFrame(_:imageBuffer:presentationTimeStamp:duration:frameProperties:infoFlagsOut:outputHandler:)](videotoolbox/vtcompressionsessionencodeframe(_:imagebuffer:presentationtimestamp:duration:frameproperties:infoflagsout:outputhandler:).md)