---
title: sourceFrame
framework: videotoolbox
role: symbol
role_heading: Instance Property
path: videotoolbox/vtopticalflowparameters/sourceframe
---

# sourceFrame

The current source frame.

## Declaration

```swift
var sourceFrame: VTFrameProcessorFrame { get }
```

## Discussion

Discussion This must be a non-nil value.

## See Also

### Inspecting the parameters

- [nextFrame](videotoolbox/vtopticalflowparameters/nextframe.md)
- [destinationOpticalFlow](videotoolbox/vtopticalflowparameters/destinationopticalflow.md)
- [submissionMode](videotoolbox/vtopticalflowparameters/submissionmode-swift.property.md)
- [VTOpticalFlowParameters.SubmissionMode](videotoolbox/vtopticalflowparameters/submissionmode-swift.enum.md)